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1612.00534
Bo Li
Bo Li, Tianfu Wu, Shuai Shao, Lun Zhang and Rufeng Chu
Object Detection via Aspect Ratio and Context Aware Region-based Convolutional Networks
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Jointly integrating aspect ratio and context has been extensively studied and shown performance improvement in traditional object detection systems such as the DPMs. It, however, has been largely ignored in deep neural network based detection systems. This paper presents a method of integrating a mixture of object models and region-based convolutional networks for accurate object detection. Each mixture component accounts for both object aspect ratio and multi-scale contextual information explicitly: (i) it exploits a mixture of tiling configurations in the RoI pooling to remedy the warping artifacts caused by a single type RoI pooling (e.g., with equally-sized 7 x 7 cells), and to respect the underlying object shapes more; (ii) it "looks from both the inside and the outside of a RoI" by incorporating contextual information at two scales: global context pooled from the whole image and local context pooled from the surrounding of a RoI. To facilitate accurate detection, this paper proposes a multi-stage detection scheme for integrating the mixture of object models, which utilizes the detection results of the model at the previous stage as the proposals for the current in both training and testing. The proposed method is called the aspect ratio and context aware region-based convolutional network (ARC-R-CNN). In experiments, ARC-R-CNN shows very competitive results with Faster R-CNN [41] and R-FCN [10] on two datasets: the PASCAL VOC and the Microsoft COCO. It obtains significantly better mAP performance using high IoU thresholds on both datasets.
[ { "version": "v1", "created": "Fri, 2 Dec 2016 01:20:02 GMT" }, { "version": "v2", "created": "Wed, 22 Mar 2017 16:28:24 GMT" } ]
2017-03-23T00:00:00
[ [ "Li", "Bo", "" ], [ "Wu", "Tianfu", "" ], [ "Shao", "Shuai", "" ], [ "Zhang", "Lun", "" ], [ "Chu", "Rufeng", "" ] ]
TITLE: Object Detection via Aspect Ratio and Context Aware Region-based Convolutional Networks ABSTRACT: Jointly integrating aspect ratio and context has been extensively studied and shown performance improvement in traditional object detection systems such as the DPMs. It, however, has been largely ignored in deep neural network based detection systems. This paper presents a method of integrating a mixture of object models and region-based convolutional networks for accurate object detection. Each mixture component accounts for both object aspect ratio and multi-scale contextual information explicitly: (i) it exploits a mixture of tiling configurations in the RoI pooling to remedy the warping artifacts caused by a single type RoI pooling (e.g., with equally-sized 7 x 7 cells), and to respect the underlying object shapes more; (ii) it "looks from both the inside and the outside of a RoI" by incorporating contextual information at two scales: global context pooled from the whole image and local context pooled from the surrounding of a RoI. To facilitate accurate detection, this paper proposes a multi-stage detection scheme for integrating the mixture of object models, which utilizes the detection results of the model at the previous stage as the proposals for the current in both training and testing. The proposed method is called the aspect ratio and context aware region-based convolutional network (ARC-R-CNN). In experiments, ARC-R-CNN shows very competitive results with Faster R-CNN [41] and R-FCN [10] on two datasets: the PASCAL VOC and the Microsoft COCO. It obtains significantly better mAP performance using high IoU thresholds on both datasets.
no_new_dataset
0.954223
1702.05060
Xuanzhe Liu
Xuanzhe Liu, Huoran Li, Xuan Lu, Tao Xie, Qiaozhu Mei, Hong Mei, Feng Feng
Mining Behavioral Patterns from Millions of Android Users
29pages
IEEE Transactions on Software Engineering, 2017
10.1109/TSE.2017.2685387
null
cs.CY cs.SE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The prevalence of smart mobile devices has promoted the popularity of mobile applications (a.k.a. apps). Supporting mobility has become a promising trend in software engineering research. This article presents an empirical study of behavioral service profiles collected from millions of users whose devices are deployed with Wandoujia, a leading Android app store service in China. The dataset of Wandoujia service profiles consists of two kinds of user behavioral data from using 0.28 million free Android apps, including (1) app management activities (i.e., downloading, updating, and uninstalling apps) from over 17 million unique users and (2) app network usage from over 6 million unique users. We explore multiple aspects of such behavioral data and present patterns of app usage. Based on the findings as well as derived knowledge, we also suggest some new open opportunities and challenges that can be explored by the research community, including app development, deployment, delivery, revenue, etc.
[ { "version": "v1", "created": "Tue, 14 Feb 2017 11:31:13 GMT" }, { "version": "v2", "created": "Wed, 22 Mar 2017 12:07:29 GMT" } ]
2017-03-23T00:00:00
[ [ "Liu", "Xuanzhe", "" ], [ "Li", "Huoran", "" ], [ "Lu", "Xuan", "" ], [ "Xie", "Tao", "" ], [ "Mei", "Qiaozhu", "" ], [ "Mei", "Hong", "" ], [ "Feng", "Feng", "" ] ]
TITLE: Mining Behavioral Patterns from Millions of Android Users ABSTRACT: The prevalence of smart mobile devices has promoted the popularity of mobile applications (a.k.a. apps). Supporting mobility has become a promising trend in software engineering research. This article presents an empirical study of behavioral service profiles collected from millions of users whose devices are deployed with Wandoujia, a leading Android app store service in China. The dataset of Wandoujia service profiles consists of two kinds of user behavioral data from using 0.28 million free Android apps, including (1) app management activities (i.e., downloading, updating, and uninstalling apps) from over 17 million unique users and (2) app network usage from over 6 million unique users. We explore multiple aspects of such behavioral data and present patterns of app usage. Based on the findings as well as derived knowledge, we also suggest some new open opportunities and challenges that can be explored by the research community, including app development, deployment, delivery, revenue, etc.
new_dataset
0.896433
1703.02437
Santiago Manen
Santiago Manen, Michael Gygli, Dengxin Dai, Luc Van Gool
PathTrack: Fast Trajectory Annotation with Path Supervision
10 pages, ICCV submission
null
null
null
cs.CV cs.LG cs.MM
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Progress in Multiple Object Tracking (MOT) has been historically limited by the size of the available datasets. We present an efficient framework to annotate trajectories and use it to produce a MOT dataset of unprecedented size. In our novel path supervision the annotator loosely follows the object with the cursor while watching the video, providing a path annotation for each object in the sequence. Our approach is able to turn such weak annotations into dense box trajectories. Our experiments on existing datasets prove that our framework produces more accurate annotations than the state of the art, in a fraction of the time. We further validate our approach by crowdsourcing the PathTrack dataset, with more than 15,000 person trajectories in 720 sequences. Tracking approaches can benefit training on such large-scale datasets, as did object recognition. We prove this by re-training an off-the-shelf person matching network, originally trained on the MOT15 dataset, almost halving the misclassification rate. Additionally, training on our data consistently improves tracking results, both on our dataset and on MOT15. On the latter, we improve the top-performing tracker (NOMT) dropping the number of IDSwitches by 18% and fragments by 5%.
[ { "version": "v1", "created": "Tue, 7 Mar 2017 15:36:39 GMT" }, { "version": "v2", "created": "Wed, 22 Mar 2017 07:08:34 GMT" } ]
2017-03-23T00:00:00
[ [ "Manen", "Santiago", "" ], [ "Gygli", "Michael", "" ], [ "Dai", "Dengxin", "" ], [ "Van Gool", "Luc", "" ] ]
TITLE: PathTrack: Fast Trajectory Annotation with Path Supervision ABSTRACT: Progress in Multiple Object Tracking (MOT) has been historically limited by the size of the available datasets. We present an efficient framework to annotate trajectories and use it to produce a MOT dataset of unprecedented size. In our novel path supervision the annotator loosely follows the object with the cursor while watching the video, providing a path annotation for each object in the sequence. Our approach is able to turn such weak annotations into dense box trajectories. Our experiments on existing datasets prove that our framework produces more accurate annotations than the state of the art, in a fraction of the time. We further validate our approach by crowdsourcing the PathTrack dataset, with more than 15,000 person trajectories in 720 sequences. Tracking approaches can benefit training on such large-scale datasets, as did object recognition. We prove this by re-training an off-the-shelf person matching network, originally trained on the MOT15 dataset, almost halving the misclassification rate. Additionally, training on our data consistently improves tracking results, both on our dataset and on MOT15. On the latter, we improve the top-performing tracker (NOMT) dropping the number of IDSwitches by 18% and fragments by 5%.
new_dataset
0.665574
1703.05884
Ashton Fagg
Hamed Kiani Galoogahi, Ashton Fagg, Chen Huang, Deva Ramanan, Simon Lucey
Need for Speed: A Benchmark for Higher Frame Rate Object Tracking
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we propose the first higher frame rate video dataset (called Need for Speed - NfS) and benchmark for visual object tracking. The dataset consists of 100 videos (380K frames) captured with now commonly available higher frame rate (240 FPS) cameras from real world scenarios. All frames are annotated with axis aligned bounding boxes and all sequences are manually labelled with nine visual attributes - such as occlusion, fast motion, background clutter, etc. Our benchmark provides an extensive evaluation of many recent and state-of-the-art trackers on higher frame rate sequences. We ranked each of these trackers according to their tracking accuracy and real-time performance. One of our surprising conclusions is that at higher frame rates, simple trackers such as correlation filters outperform complex methods based on deep networks. This suggests that for practical applications (such as in robotics or embedded vision), one needs to carefully tradeoff bandwidth constraints associated with higher frame rate acquisition, computational costs of real-time analysis, and the required application accuracy. Our dataset and benchmark allows for the first time (to our knowledge) systematic exploration of such issues, and will be made available to allow for further research in this space.
[ { "version": "v1", "created": "Fri, 17 Mar 2017 04:18:25 GMT" }, { "version": "v2", "created": "Tue, 21 Mar 2017 22:35:09 GMT" } ]
2017-03-23T00:00:00
[ [ "Galoogahi", "Hamed Kiani", "" ], [ "Fagg", "Ashton", "" ], [ "Huang", "Chen", "" ], [ "Ramanan", "Deva", "" ], [ "Lucey", "Simon", "" ] ]
TITLE: Need for Speed: A Benchmark for Higher Frame Rate Object Tracking ABSTRACT: In this paper, we propose the first higher frame rate video dataset (called Need for Speed - NfS) and benchmark for visual object tracking. The dataset consists of 100 videos (380K frames) captured with now commonly available higher frame rate (240 FPS) cameras from real world scenarios. All frames are annotated with axis aligned bounding boxes and all sequences are manually labelled with nine visual attributes - such as occlusion, fast motion, background clutter, etc. Our benchmark provides an extensive evaluation of many recent and state-of-the-art trackers on higher frame rate sequences. We ranked each of these trackers according to their tracking accuracy and real-time performance. One of our surprising conclusions is that at higher frame rates, simple trackers such as correlation filters outperform complex methods based on deep networks. This suggests that for practical applications (such as in robotics or embedded vision), one needs to carefully tradeoff bandwidth constraints associated with higher frame rate acquisition, computational costs of real-time analysis, and the required application accuracy. Our dataset and benchmark allows for the first time (to our knowledge) systematic exploration of such issues, and will be made available to allow for further research in this space.
new_dataset
0.967595
1703.07255
Hao Wang
Hao Wang, Xiaodan Liang, Hao Zhang, Dit-Yan Yeung, Eric P. Xing
ZM-Net: Real-time Zero-shot Image Manipulation Network
null
null
null
null
cs.CV cs.AI cs.GR cs.LG stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Many problems in image processing and computer vision (e.g. colorization, style transfer) can be posed as 'manipulating' an input image into a corresponding output image given a user-specified guiding signal. A holy-grail solution towards generic image manipulation should be able to efficiently alter an input image with any personalized signals (even signals unseen during training), such as diverse paintings and arbitrary descriptive attributes. However, existing methods are either inefficient to simultaneously process multiple signals (let alone generalize to unseen signals), or unable to handle signals from other modalities. In this paper, we make the first attempt to address the zero-shot image manipulation task. We cast this problem as manipulating an input image according to a parametric model whose key parameters can be conditionally generated from any guiding signal (even unseen ones). To this end, we propose the Zero-shot Manipulation Net (ZM-Net), a fully-differentiable architecture that jointly optimizes an image-transformation network (TNet) and a parameter network (PNet). The PNet learns to generate key transformation parameters for the TNet given any guiding signal while the TNet performs fast zero-shot image manipulation according to both signal-dependent parameters from the PNet and signal-invariant parameters from the TNet itself. Extensive experiments show that our ZM-Net can perform high-quality image manipulation conditioned on different forms of guiding signals (e.g. style images and attributes) in real-time (tens of milliseconds per image) even for unseen signals. Moreover, a large-scale style dataset with over 20,000 style images is also constructed to promote further research.
[ { "version": "v1", "created": "Tue, 21 Mar 2017 15:01:59 GMT" }, { "version": "v2", "created": "Wed, 22 Mar 2017 17:08:40 GMT" } ]
2017-03-23T00:00:00
[ [ "Wang", "Hao", "" ], [ "Liang", "Xiaodan", "" ], [ "Zhang", "Hao", "" ], [ "Yeung", "Dit-Yan", "" ], [ "Xing", "Eric P.", "" ] ]
TITLE: ZM-Net: Real-time Zero-shot Image Manipulation Network ABSTRACT: Many problems in image processing and computer vision (e.g. colorization, style transfer) can be posed as 'manipulating' an input image into a corresponding output image given a user-specified guiding signal. A holy-grail solution towards generic image manipulation should be able to efficiently alter an input image with any personalized signals (even signals unseen during training), such as diverse paintings and arbitrary descriptive attributes. However, existing methods are either inefficient to simultaneously process multiple signals (let alone generalize to unseen signals), or unable to handle signals from other modalities. In this paper, we make the first attempt to address the zero-shot image manipulation task. We cast this problem as manipulating an input image according to a parametric model whose key parameters can be conditionally generated from any guiding signal (even unseen ones). To this end, we propose the Zero-shot Manipulation Net (ZM-Net), a fully-differentiable architecture that jointly optimizes an image-transformation network (TNet) and a parameter network (PNet). The PNet learns to generate key transformation parameters for the TNet given any guiding signal while the TNet performs fast zero-shot image manipulation according to both signal-dependent parameters from the PNet and signal-invariant parameters from the TNet itself. Extensive experiments show that our ZM-Net can perform high-quality image manipulation conditioned on different forms of guiding signals (e.g. style images and attributes) in real-time (tens of milliseconds per image) even for unseen signals. Moreover, a large-scale style dataset with over 20,000 style images is also constructed to promote further research.
no_new_dataset
0.948728
1703.07362
James Bagrow
James P. Bagrow
Information spreading during emergencies and anomalous events
19 pages, 11 figures
null
null
null
cs.SI cs.CY physics.data-an physics.soc-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The most critical time for information to spread is in the aftermath of a serious emergency, crisis, or disaster. Individuals affected by such situations can now turn to an array of communication channels, from mobile phone calls and text messages to social media posts, when alerting social ties. These channels drastically improve the speed of information in a time-sensitive event, and provide extant records of human dynamics during and afterward the event. Retrospective analysis of such anomalous events provides researchers with a class of "found experiments" that may be used to better understand social spreading. In this chapter, we study information spreading due to a number of emergency events, including the Boston Marathon Bombing and a plane crash at a western European airport. We also contrast the different information which may be gleaned by social media data compared with mobile phone data and we estimate the rate of anomalous events in a mobile phone dataset using a proposed anomaly detection method.
[ { "version": "v1", "created": "Tue, 21 Mar 2017 18:00:07 GMT" } ]
2017-03-23T00:00:00
[ [ "Bagrow", "James P.", "" ] ]
TITLE: Information spreading during emergencies and anomalous events ABSTRACT: The most critical time for information to spread is in the aftermath of a serious emergency, crisis, or disaster. Individuals affected by such situations can now turn to an array of communication channels, from mobile phone calls and text messages to social media posts, when alerting social ties. These channels drastically improve the speed of information in a time-sensitive event, and provide extant records of human dynamics during and afterward the event. Retrospective analysis of such anomalous events provides researchers with a class of "found experiments" that may be used to better understand social spreading. In this chapter, we study information spreading due to a number of emergency events, including the Boston Marathon Bombing and a plane crash at a western European airport. We also contrast the different information which may be gleaned by social media data compared with mobile phone data and we estimate the rate of anomalous events in a mobile phone dataset using a proposed anomaly detection method.
no_new_dataset
0.939081
1703.07402
Nicolai Wojke
Nicolai Wojke and Alex Bewley and Dietrich Paulus
Simple Online and Realtime Tracking with a Deep Association Metric
5 pages, 1 figure
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Simple Online and Realtime Tracking (SORT) is a pragmatic approach to multiple object tracking with a focus on simple, effective algorithms. In this paper, we integrate appearance information to improve the performance of SORT. Due to this extension we are able to track objects through longer periods of occlusions, effectively reducing the number of identity switches. In spirit of the original framework we place much of the computational complexity into an offline pre-training stage where we learn a deep association metric on a large-scale person re-identification dataset. During online application, we establish measurement-to-track associations using nearest neighbor queries in visual appearance space. Experimental evaluation shows that our extensions reduce the number of identity switches by 45%, achieving overall competitive performance at high frame rates.
[ { "version": "v1", "created": "Tue, 21 Mar 2017 19:40:25 GMT" } ]
2017-03-23T00:00:00
[ [ "Wojke", "Nicolai", "" ], [ "Bewley", "Alex", "" ], [ "Paulus", "Dietrich", "" ] ]
TITLE: Simple Online and Realtime Tracking with a Deep Association Metric ABSTRACT: Simple Online and Realtime Tracking (SORT) is a pragmatic approach to multiple object tracking with a focus on simple, effective algorithms. In this paper, we integrate appearance information to improve the performance of SORT. Due to this extension we are able to track objects through longer periods of occlusions, effectively reducing the number of identity switches. In spirit of the original framework we place much of the computational complexity into an offline pre-training stage where we learn a deep association metric on a large-scale person re-identification dataset. During online application, we establish measurement-to-track associations using nearest neighbor queries in visual appearance space. Experimental evaluation shows that our extensions reduce the number of identity switches by 45%, achieving overall competitive performance at high frame rates.
no_new_dataset
0.951142
1703.07403
Kevin Moerman
Andr\'e M.J. Sprengers, Matthan W.A. Caan, Kevin M. Moerman, Aart J. Nederveen, Rolf M.J.N. Lamerichs, Jaap Stoker
A scale space based algorithm for automated segmentation of single shot tagged MRI of shearing deformation
null
Magnetic Resonance Materials in Physics, Biology and Medicine, April 2013, Volume 26, Issue 2, pp 229-238
10.1007/s10334-012-0332-9
null
physics.med-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Object This study proposes a scale space based algorithm for automated segmentation of single-shot tagged images of modest SNR. Furthermore the algorithm was designed for analysis of discontinuous or shearing types of motion, i.e. segmentation of broken tag patterns. Materials and methods The proposed algorithm utilizes non-linear scale space for automatic segmentation of single-shot tagged images. The algorithm's ability to automatically segment tagged shearing motion was evaluated in a numerical simulation and in vivo. A typical shearing deformation was simulated in a Shepp-Logan phantom allowing for quantitative evaluation of the algorithm's success rate as a function of both SNR and the amount of deformation. For a qualitative in vivo evaluation tagged images showing deformations in the calf muscles and eye movement in a healthy volunteer were acquired. Results Both the numerical simulation and the in vivo tagged data demonstrated the algorithm's ability for automated segmentation of single-shot tagged MR provided that SNR of the images is above 10 and the amount of deformation does not exceed the tag spacing. The latter constraint can be met by adjusting the tag delay or the tag spacing. Conclusion The scale space based algorithm for automatic segmentation of single-shot tagged MR enables the application of tagged MR to complex (shearing) deformation and the processing of datasets with relatively low SNR.
[ { "version": "v1", "created": "Tue, 21 Mar 2017 19:41:27 GMT" } ]
2017-03-23T00:00:00
[ [ "Sprengers", "André M. J.", "" ], [ "Caan", "Matthan W. A.", "" ], [ "Moerman", "Kevin M.", "" ], [ "Nederveen", "Aart J.", "" ], [ "Lamerichs", "Rolf M. J. N.", "" ], [ "Stoker", "Jaap", "" ] ]
TITLE: A scale space based algorithm for automated segmentation of single shot tagged MRI of shearing deformation ABSTRACT: Object This study proposes a scale space based algorithm for automated segmentation of single-shot tagged images of modest SNR. Furthermore the algorithm was designed for analysis of discontinuous or shearing types of motion, i.e. segmentation of broken tag patterns. Materials and methods The proposed algorithm utilizes non-linear scale space for automatic segmentation of single-shot tagged images. The algorithm's ability to automatically segment tagged shearing motion was evaluated in a numerical simulation and in vivo. A typical shearing deformation was simulated in a Shepp-Logan phantom allowing for quantitative evaluation of the algorithm's success rate as a function of both SNR and the amount of deformation. For a qualitative in vivo evaluation tagged images showing deformations in the calf muscles and eye movement in a healthy volunteer were acquired. Results Both the numerical simulation and the in vivo tagged data demonstrated the algorithm's ability for automated segmentation of single-shot tagged MR provided that SNR of the images is above 10 and the amount of deformation does not exceed the tag spacing. The latter constraint can be met by adjusting the tag delay or the tag spacing. Conclusion The scale space based algorithm for automatic segmentation of single-shot tagged MR enables the application of tagged MR to complex (shearing) deformation and the processing of datasets with relatively low SNR.
no_new_dataset
0.952042
1703.07473
Niko S\"underhauf
Feras Dayoub, Niko S\"underhauf, Peter Corke
Episode-Based Active Learning with Bayesian Neural Networks
null
null
null
null
cs.CV cs.LG stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate different strategies for active learning with Bayesian deep neural networks. We focus our analysis on scenarios where new, unlabeled data is obtained episodically, such as commonly encountered in mobile robotics applications. An evaluation of different strategies for acquisition, updating, and final training on the CIFAR-10 dataset shows that incremental network updates with final training on the accumulated acquisition set are essential for best performance, while limiting the amount of required human labeling labor.
[ { "version": "v1", "created": "Tue, 21 Mar 2017 23:56:51 GMT" } ]
2017-03-23T00:00:00
[ [ "Dayoub", "Feras", "" ], [ "Sünderhauf", "Niko", "" ], [ "Corke", "Peter", "" ] ]
TITLE: Episode-Based Active Learning with Bayesian Neural Networks ABSTRACT: We investigate different strategies for active learning with Bayesian deep neural networks. We focus our analysis on scenarios where new, unlabeled data is obtained episodically, such as commonly encountered in mobile robotics applications. An evaluation of different strategies for acquisition, updating, and final training on the CIFAR-10 dataset shows that incremental network updates with final training on the accumulated acquisition set are essential for best performance, while limiting the amount of required human labeling labor.
no_new_dataset
0.950273
1703.07506
Marc Goessling
Marc Goessling
LogitBoost autoregressive networks
null
null
10.1016/j.csda.2017.03.010
null
stat.ML cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Multivariate binary distributions can be decomposed into products of univariate conditional distributions. Recently popular approaches have modeled these conditionals through neural networks with sophisticated weight-sharing structures. It is shown that state-of-the-art performance on several standard benchmark datasets can actually be achieved by training separate probability estimators for each dimension. In that case, model training can be trivially parallelized over data dimensions. On the other hand, complexity control has to be performed for each learned conditional distribution. Three possible methods are considered and experimentally compared. The estimator that is employed for each conditional is LogitBoost. Similarities and differences between the proposed approach and autoregressive models based on neural networks are discussed in detail.
[ { "version": "v1", "created": "Wed, 22 Mar 2017 03:26:32 GMT" } ]
2017-03-23T00:00:00
[ [ "Goessling", "Marc", "" ] ]
TITLE: LogitBoost autoregressive networks ABSTRACT: Multivariate binary distributions can be decomposed into products of univariate conditional distributions. Recently popular approaches have modeled these conditionals through neural networks with sophisticated weight-sharing structures. It is shown that state-of-the-art performance on several standard benchmark datasets can actually be achieved by training separate probability estimators for each dimension. In that case, model training can be trivially parallelized over data dimensions. On the other hand, complexity control has to be performed for each learned conditional distribution. Three possible methods are considered and experimentally compared. The estimator that is employed for each conditional is LogitBoost. Similarities and differences between the proposed approach and autoregressive models based on neural networks are discussed in detail.
no_new_dataset
0.943556
1703.07579
Zhongwen Xu
Fan Wu, Zhongwen Xu, Yi Yang
An End-to-End Approach to Natural Language Object Retrieval via Context-Aware Deep Reinforcement Learning
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose an end-to-end approach to the natural language object retrieval task, which localizes an object within an image according to a natural language description, i.e., referring expression. Previous works divide this problem into two independent stages: first, compute region proposals from the image without the exploration of the language description; second, score the object proposals with regard to the referring expression and choose the top-ranked proposals. The object proposals are generated independently from the referring expression, which makes the proposal generation redundant and even irrelevant to the referred object. In this work, we train an agent with deep reinforcement learning, which learns to move and reshape a bounding box to localize the object according to the referring expression. We incorporate both the spatial and temporal context information into the training procedure. By simultaneously exploiting local visual information, the spatial and temporal context and the referring language a priori, the agent selects an appropriate action to take at each time. A special action is defined to indicate when the agent finds the referred object, and terminate the procedure. We evaluate our model on various datasets, and our algorithm significantly outperforms the compared algorithms. Notably, the accuracy improvement of our method over the recent method GroundeR and SCRC on the ReferItGame dataset are 7.67% and 18.25%, respectively.
[ { "version": "v1", "created": "Wed, 22 Mar 2017 09:25:49 GMT" } ]
2017-03-23T00:00:00
[ [ "Wu", "Fan", "" ], [ "Xu", "Zhongwen", "" ], [ "Yang", "Yi", "" ] ]
TITLE: An End-to-End Approach to Natural Language Object Retrieval via Context-Aware Deep Reinforcement Learning ABSTRACT: We propose an end-to-end approach to the natural language object retrieval task, which localizes an object within an image according to a natural language description, i.e., referring expression. Previous works divide this problem into two independent stages: first, compute region proposals from the image without the exploration of the language description; second, score the object proposals with regard to the referring expression and choose the top-ranked proposals. The object proposals are generated independently from the referring expression, which makes the proposal generation redundant and even irrelevant to the referred object. In this work, we train an agent with deep reinforcement learning, which learns to move and reshape a bounding box to localize the object according to the referring expression. We incorporate both the spatial and temporal context information into the training procedure. By simultaneously exploiting local visual information, the spatial and temporal context and the referring language a priori, the agent selects an appropriate action to take at each time. A special action is defined to indicate when the agent finds the referred object, and terminate the procedure. We evaluate our model on various datasets, and our algorithm significantly outperforms the compared algorithms. Notably, the accuracy improvement of our method over the recent method GroundeR and SCRC on the ReferItGame dataset are 7.67% and 18.25%, respectively.
no_new_dataset
0.947381
1703.07617
Jun Sun
Yuanzhen Ji, Jun Sun, Anisoara Nica, Zbigniew Jerzak, Gregor Hackenbroich, Christof Fetzer
Quality-Driven Disorder Handling for M-way Sliding Window Stream Joins
12 pages, 11 figures, IEEE ICDE 2016
null
10.1109/ICDE.2016.7498265
null
cs.DB
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Sliding window join is one of the most important operators for stream applications. To produce high quality join results, a stream processing system must deal with the ubiquitous disorder within input streams which is caused by network delay, asynchronous source clocks, etc. Disorder handling involves an inevitable tradeoff between the latency and the quality of produced join results. To meet different requirements of stream applications, it is desirable to provide a user-configurable result-latency vs. result-quality tradeoff. Existing disorder handling approaches either do not provide such configurability, or support only user-specified latency constraints. In this work, we advocate the idea of quality-driven disorder handling, and propose a buffer-based disorder handling approach for sliding window joins, which minimizes sizes of input-sorting buffers, thus the result latency, while respecting user-specified result-quality requirements. The core of our approach is an analytical model which directly captures the relationship between sizes of input buffers and the produced result quality. Our approach is generic. It supports m-way sliding window joins with arbitrary join conditions. Experiments on real-world and synthetic datasets show that, compared to the state of the art, our approach can reduce the result latency incurred by disorder handling by up to 95% while providing the same level of result quality.
[ { "version": "v1", "created": "Wed, 22 Mar 2017 12:27:21 GMT" } ]
2017-03-23T00:00:00
[ [ "Ji", "Yuanzhen", "" ], [ "Sun", "Jun", "" ], [ "Nica", "Anisoara", "" ], [ "Jerzak", "Zbigniew", "" ], [ "Hackenbroich", "Gregor", "" ], [ "Fetzer", "Christof", "" ] ]
TITLE: Quality-Driven Disorder Handling for M-way Sliding Window Stream Joins ABSTRACT: Sliding window join is one of the most important operators for stream applications. To produce high quality join results, a stream processing system must deal with the ubiquitous disorder within input streams which is caused by network delay, asynchronous source clocks, etc. Disorder handling involves an inevitable tradeoff between the latency and the quality of produced join results. To meet different requirements of stream applications, it is desirable to provide a user-configurable result-latency vs. result-quality tradeoff. Existing disorder handling approaches either do not provide such configurability, or support only user-specified latency constraints. In this work, we advocate the idea of quality-driven disorder handling, and propose a buffer-based disorder handling approach for sliding window joins, which minimizes sizes of input-sorting buffers, thus the result latency, while respecting user-specified result-quality requirements. The core of our approach is an analytical model which directly captures the relationship between sizes of input buffers and the produced result quality. Our approach is generic. It supports m-way sliding window joins with arbitrary join conditions. Experiments on real-world and synthetic datasets show that, compared to the state of the art, our approach can reduce the result latency incurred by disorder handling by up to 95% while providing the same level of result quality.
no_new_dataset
0.948775
1703.07625
Joris Gu\'erin
Joris Gu\'erin, Olivier Gibaru, St\'ephane Thiery and Eric Nyiri
Clustering for Different Scales of Measurement - the Gap-Ratio Weighted K-means Algorithm
13 pages, 6 figures, 2 tables. This paper is under the review process for AIAP 2017
null
null
null
cs.LG cs.DS stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper describes a method for clustering data that are spread out over large regions and which dimensions are on different scales of measurement. Such an algorithm was developed to implement a robotics application consisting in sorting and storing objects in an unsupervised way. The toy dataset used to validate such application consists of Lego bricks of different shapes and colors. The uncontrolled lighting conditions together with the use of RGB color features, respectively involve data with a large spread and different levels of measurement between data dimensions. To overcome the combination of these two characteristics in the data, we have developed a new weighted K-means algorithm, called gap-ratio K-means, which consists in weighting each dimension of the feature space before running the K-means algorithm. The weight associated with a feature is proportional to the ratio of the biggest gap between two consecutive data points, and the average of all the other gaps. This method is compared with two other variants of K-means on the Lego bricks clustering problem as well as two other common classification datasets.
[ { "version": "v1", "created": "Wed, 22 Mar 2017 12:50:15 GMT" } ]
2017-03-23T00:00:00
[ [ "Guérin", "Joris", "" ], [ "Gibaru", "Olivier", "" ], [ "Thiery", "Stéphane", "" ], [ "Nyiri", "Eric", "" ] ]
TITLE: Clustering for Different Scales of Measurement - the Gap-Ratio Weighted K-means Algorithm ABSTRACT: This paper describes a method for clustering data that are spread out over large regions and which dimensions are on different scales of measurement. Such an algorithm was developed to implement a robotics application consisting in sorting and storing objects in an unsupervised way. The toy dataset used to validate such application consists of Lego bricks of different shapes and colors. The uncontrolled lighting conditions together with the use of RGB color features, respectively involve data with a large spread and different levels of measurement between data dimensions. To overcome the combination of these two characteristics in the data, we have developed a new weighted K-means algorithm, called gap-ratio K-means, which consists in weighting each dimension of the feature space before running the K-means algorithm. The weight associated with a feature is proportional to the ratio of the biggest gap between two consecutive data points, and the average of all the other gaps. This method is compared with two other variants of K-means on the Lego bricks clustering problem as well as two other common classification datasets.
new_dataset
0.578322
1512.05742
Iulian Vlad Serban
Iulian Vlad Serban, Ryan Lowe, Peter Henderson, Laurent Charlin, Joelle Pineau
A Survey of Available Corpora for Building Data-Driven Dialogue Systems
56 pages including references and appendix, 5 tables and 1 figure; Under review for the Dialogue & Discourse journal. Update: paper has been rewritten and now includes several new datasets
null
null
null
cs.CL cs.AI cs.HC cs.LG stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
During the past decade, several areas of speech and language understanding have witnessed substantial breakthroughs from the use of data-driven models. In the area of dialogue systems, the trend is less obvious, and most practical systems are still built through significant engineering and expert knowledge. Nevertheless, several recent results suggest that data-driven approaches are feasible and quite promising. To facilitate research in this area, we have carried out a wide survey of publicly available datasets suitable for data-driven learning of dialogue systems. We discuss important characteristics of these datasets, how they can be used to learn diverse dialogue strategies, and their other potential uses. We also examine methods for transfer learning between datasets and the use of external knowledge. Finally, we discuss appropriate choice of evaluation metrics for the learning objective.
[ { "version": "v1", "created": "Thu, 17 Dec 2015 19:52:39 GMT" }, { "version": "v2", "created": "Tue, 22 Dec 2015 04:58:05 GMT" }, { "version": "v3", "created": "Tue, 21 Mar 2017 01:15:32 GMT" } ]
2017-03-22T00:00:00
[ [ "Serban", "Iulian Vlad", "" ], [ "Lowe", "Ryan", "" ], [ "Henderson", "Peter", "" ], [ "Charlin", "Laurent", "" ], [ "Pineau", "Joelle", "" ] ]
TITLE: A Survey of Available Corpora for Building Data-Driven Dialogue Systems ABSTRACT: During the past decade, several areas of speech and language understanding have witnessed substantial breakthroughs from the use of data-driven models. In the area of dialogue systems, the trend is less obvious, and most practical systems are still built through significant engineering and expert knowledge. Nevertheless, several recent results suggest that data-driven approaches are feasible and quite promising. To facilitate research in this area, we have carried out a wide survey of publicly available datasets suitable for data-driven learning of dialogue systems. We discuss important characteristics of these datasets, how they can be used to learn diverse dialogue strategies, and their other potential uses. We also examine methods for transfer learning between datasets and the use of external knowledge. Finally, we discuss appropriate choice of evaluation metrics for the learning objective.
no_new_dataset
0.945399
1603.06765
Xiao Liu
Xiao Liu, Tian Xia, Jiang Wang, Yi Yang, Feng Zhou, Yuanqing Lin
Fully Convolutional Attention Networks for Fine-Grained Recognition
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Fine-grained recognition is challenging due to its subtle local inter-class differences versus large intra-class variations such as poses. A key to address this problem is to localize discriminative parts to extract pose-invariant features. However, ground-truth part annotations can be expensive to acquire. Moreover, it is hard to define parts for many fine-grained classes. This work introduces Fully Convolutional Attention Networks (FCANs), a reinforcement learning framework to optimally glimpse local discriminative regions adaptive to different fine-grained domains. Compared to previous methods, our approach enjoys three advantages: 1) the weakly-supervised reinforcement learning procedure requires no expensive part annotations; 2) the fully-convolutional architecture speeds up both training and testing; 3) the greedy reward strategy accelerates the convergence of the learning. We demonstrate the effectiveness of our method with extensive experiments on four challenging fine-grained benchmark datasets, including CUB-200-2011, Stanford Dogs, Stanford Cars and Food-101.
[ { "version": "v1", "created": "Tue, 22 Mar 2016 12:45:20 GMT" }, { "version": "v2", "created": "Sat, 4 Jun 2016 11:46:30 GMT" }, { "version": "v3", "created": "Mon, 21 Nov 2016 11:12:45 GMT" }, { "version": "v4", "created": "Tue, 21 Mar 2017 02:08:15 GMT" } ]
2017-03-22T00:00:00
[ [ "Liu", "Xiao", "" ], [ "Xia", "Tian", "" ], [ "Wang", "Jiang", "" ], [ "Yang", "Yi", "" ], [ "Zhou", "Feng", "" ], [ "Lin", "Yuanqing", "" ] ]
TITLE: Fully Convolutional Attention Networks for Fine-Grained Recognition ABSTRACT: Fine-grained recognition is challenging due to its subtle local inter-class differences versus large intra-class variations such as poses. A key to address this problem is to localize discriminative parts to extract pose-invariant features. However, ground-truth part annotations can be expensive to acquire. Moreover, it is hard to define parts for many fine-grained classes. This work introduces Fully Convolutional Attention Networks (FCANs), a reinforcement learning framework to optimally glimpse local discriminative regions adaptive to different fine-grained domains. Compared to previous methods, our approach enjoys three advantages: 1) the weakly-supervised reinforcement learning procedure requires no expensive part annotations; 2) the fully-convolutional architecture speeds up both training and testing; 3) the greedy reward strategy accelerates the convergence of the learning. We demonstrate the effectiveness of our method with extensive experiments on four challenging fine-grained benchmark datasets, including CUB-200-2011, Stanford Dogs, Stanford Cars and Food-101.
no_new_dataset
0.948058
1606.09284
Jacopo Grilli
Jacopo Grilli, Matteo Osella, Andrew S. Kennard, Marco Cosentino Lagomarsino
Relevant parameters in models of cell division control
15 pages, 5 figures
Phys. Rev. E 95, 032411 (2017)
10.1103/PhysRevE.95.032411
null
q-bio.CB cond-mat.stat-mech physics.bio-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A recent burst of dynamic single-cell growth-division data makes it possible to characterize the stochastic dynamics of cell division control in bacteria. Different modeling frameworks were used to infer specific mechanisms from such data, but the links between frameworks are poorly explored, with relevant consequences for how well any particular mechanism can be supported by the data. Here, we describe a simple and generic framework in which two common formalisms can be used interchangeably: (i) a continuous-time division process described by a hazard function and (ii) a discrete-time equation describing cell size across generations (where the unit of time is a cell cycle). In our framework, this second process is a discrete-time Langevin equation with a simple physical analogue. By perturbative expansion around the mean initial size (or inter-division time), we show explicitly how this framework describes a wide range of division control mechanisms, including combinations of time and size control, as well as the constant added size mechanism recently found to capture several aspects of the cell division behavior of different bacteria. As we show by analytical estimates and numerical simulation, the available data are characterized with great precision by the first-order approximation of this expansion. Hence, a single dimensionless parameter defines the strength and the action of the division control. However, this parameter may emerge from several mechanisms, which are distinguished only by higher-order terms in our perturbative expansion. An analytical estimate of the sample size needed to distinguish between second-order effects shows that this is larger than what is available in the current datasets. These results provide a unified framework for future studies and clarify the relevant parameters at play in the control of cell division.
[ { "version": "v1", "created": "Wed, 29 Jun 2016 20:58:36 GMT" } ]
2017-03-22T00:00:00
[ [ "Grilli", "Jacopo", "" ], [ "Osella", "Matteo", "" ], [ "Kennard", "Andrew S.", "" ], [ "Lagomarsino", "Marco Cosentino", "" ] ]
TITLE: Relevant parameters in models of cell division control ABSTRACT: A recent burst of dynamic single-cell growth-division data makes it possible to characterize the stochastic dynamics of cell division control in bacteria. Different modeling frameworks were used to infer specific mechanisms from such data, but the links between frameworks are poorly explored, with relevant consequences for how well any particular mechanism can be supported by the data. Here, we describe a simple and generic framework in which two common formalisms can be used interchangeably: (i) a continuous-time division process described by a hazard function and (ii) a discrete-time equation describing cell size across generations (where the unit of time is a cell cycle). In our framework, this second process is a discrete-time Langevin equation with a simple physical analogue. By perturbative expansion around the mean initial size (or inter-division time), we show explicitly how this framework describes a wide range of division control mechanisms, including combinations of time and size control, as well as the constant added size mechanism recently found to capture several aspects of the cell division behavior of different bacteria. As we show by analytical estimates and numerical simulation, the available data are characterized with great precision by the first-order approximation of this expansion. Hence, a single dimensionless parameter defines the strength and the action of the division control. However, this parameter may emerge from several mechanisms, which are distinguished only by higher-order terms in our perturbative expansion. An analytical estimate of the sample size needed to distinguish between second-order effects shows that this is larger than what is available in the current datasets. These results provide a unified framework for future studies and clarify the relevant parameters at play in the control of cell division.
no_new_dataset
0.946448
1607.02204
Giuseppe Lisanti
Giuseppe Lisanti, Svebor Karaman, Iacopo Masi
Multi Channel-Kernel Canonical Correlation Analysis for Cross-View Person Re-Identification
The latest/updated version of the manuscript with more experiments can be found at https://doi.org/10.1145/3038916. Please cite the paper using https://doi.org/10.1145/3038916
ACM Transactions on Multimedia Computing, Communications, and Applications (TOMM), Volume 13 Issue 2, March 2017
10.1145/3038916
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we introduce a method to overcome one of the main challenges of person re-identification in multi-camera networks, namely cross-view appearance changes. The proposed solution addresses the extreme variability of person appearance in different camera views by exploiting multiple feature representations. For each feature, Kernel Canonical Correlation Analysis (KCCA) with different kernels is exploited to learn several projection spaces in which the appearance correlation between samples of the same person observed from different cameras is maximized. An iterative logistic regression is finally used to select and weigh the contributions of each feature projections and perform the matching between the two views. Experimental evaluation shows that the proposed solution obtains comparable performance on VIPeR and PRID 450s datasets and improves on PRID and CUHK01 datasets with respect to the state of the art.
[ { "version": "v1", "created": "Fri, 8 Jul 2016 00:40:38 GMT" }, { "version": "v2", "created": "Tue, 21 Mar 2017 10:14:10 GMT" } ]
2017-03-22T00:00:00
[ [ "Lisanti", "Giuseppe", "" ], [ "Karaman", "Svebor", "" ], [ "Masi", "Iacopo", "" ] ]
TITLE: Multi Channel-Kernel Canonical Correlation Analysis for Cross-View Person Re-Identification ABSTRACT: In this paper we introduce a method to overcome one of the main challenges of person re-identification in multi-camera networks, namely cross-view appearance changes. The proposed solution addresses the extreme variability of person appearance in different camera views by exploiting multiple feature representations. For each feature, Kernel Canonical Correlation Analysis (KCCA) with different kernels is exploited to learn several projection spaces in which the appearance correlation between samples of the same person observed from different cameras is maximized. An iterative logistic regression is finally used to select and weigh the contributions of each feature projections and perform the matching between the two views. Experimental evaluation shows that the proposed solution obtains comparable performance on VIPeR and PRID 450s datasets and improves on PRID and CUHK01 datasets with respect to the state of the art.
no_new_dataset
0.950641
1611.08906
Yiannis Andreopoulos
Aaron Chadha and Yiannis Andreopoulos
Voronoi-based compact image descriptors: Efficient Region-of-Interest retrieval with VLAD and deep-learning-based descriptors
IEEE Transaction on Multimedia, to appear
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the problem of image retrieval based on visual queries when the latter comprise arbitrary regions-of-interest (ROI) rather than entire images. Our proposal is a compact image descriptor that combines the state-of-the-art in content-based descriptor extraction with a multi-level, Voronoi-based spatial partitioning of each dataset image. The proposed multi-level Voronoi-based encoding uses a spatial hierarchical K-means over interest-point locations, and computes a content-based descriptor over each cell. In order to reduce the matching complexity with minimal or no sacrifice in retrieval performance: (i) we utilize the tree structure of the spatial hierarchical K-means to perform a top-to-bottom pruning for local similarity maxima; (ii) we propose a new image similarity score that combines relevant information from all partition levels into a single measure for similarity; (iii) we combine our proposal with a novel and efficient approach for optimal bit allocation within quantized descriptor representations. By deriving both a Voronoi-based VLAD descriptor (termed as Fast-VVLAD) and a Voronoi-based deep convolutional neural network (CNN) descriptor (termed as Fast-VDCNN), we demonstrate that our Voronoi-based framework is agnostic to the descriptor basis, and can easily be slotted into existing frameworks. Via a range of ROI queries in two standard datasets, it is shown that the Voronoi-based descriptors achieve comparable or higher mean Average Precision against conventional grid-based spatial search, while offering more than two-fold reduction in complexity. Finally, beyond ROI queries, we show that Voronoi partitioning improves the geometric invariance of compact CNN descriptors, thereby resulting in competitive performance to the current state-of-the-art on whole image retrieval.
[ { "version": "v1", "created": "Sun, 27 Nov 2016 20:35:48 GMT" }, { "version": "v2", "created": "Mon, 20 Mar 2017 18:37:56 GMT" } ]
2017-03-22T00:00:00
[ [ "Chadha", "Aaron", "" ], [ "Andreopoulos", "Yiannis", "" ] ]
TITLE: Voronoi-based compact image descriptors: Efficient Region-of-Interest retrieval with VLAD and deep-learning-based descriptors ABSTRACT: We investigate the problem of image retrieval based on visual queries when the latter comprise arbitrary regions-of-interest (ROI) rather than entire images. Our proposal is a compact image descriptor that combines the state-of-the-art in content-based descriptor extraction with a multi-level, Voronoi-based spatial partitioning of each dataset image. The proposed multi-level Voronoi-based encoding uses a spatial hierarchical K-means over interest-point locations, and computes a content-based descriptor over each cell. In order to reduce the matching complexity with minimal or no sacrifice in retrieval performance: (i) we utilize the tree structure of the spatial hierarchical K-means to perform a top-to-bottom pruning for local similarity maxima; (ii) we propose a new image similarity score that combines relevant information from all partition levels into a single measure for similarity; (iii) we combine our proposal with a novel and efficient approach for optimal bit allocation within quantized descriptor representations. By deriving both a Voronoi-based VLAD descriptor (termed as Fast-VVLAD) and a Voronoi-based deep convolutional neural network (CNN) descriptor (termed as Fast-VDCNN), we demonstrate that our Voronoi-based framework is agnostic to the descriptor basis, and can easily be slotted into existing frameworks. Via a range of ROI queries in two standard datasets, it is shown that the Voronoi-based descriptors achieve comparable or higher mean Average Precision against conventional grid-based spatial search, while offering more than two-fold reduction in complexity. Finally, beyond ROI queries, we show that Voronoi partitioning improves the geometric invariance of compact CNN descriptors, thereby resulting in competitive performance to the current state-of-the-art on whole image retrieval.
no_new_dataset
0.956022
1703.05161
Christian Reinbacher
Christian Reinbacher and Gottfried Munda and Thomas Pock
Real-Time Panoramic Tracking for Event Cameras
Accepted to International Conference on Computational Photography 2017
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Event cameras are a paradigm shift in camera technology. Instead of full frames, the sensor captures a sparse set of events caused by intensity changes. Since only the changes are transferred, those cameras are able to capture quick movements of objects in the scene or of the camera itself. In this work we propose a novel method to perform camera tracking of event cameras in a panoramic setting with three degrees of freedom. We propose a direct camera tracking formulation, similar to state-of-the-art in visual odometry. We show that the minimal information needed for simultaneous tracking and mapping is the spatial position of events, without using the appearance of the imaged scene point. We verify the robustness to fast camera movements and dynamic objects in the scene on a recently proposed dataset and self-recorded sequences.
[ { "version": "v1", "created": "Wed, 15 Mar 2017 14:03:47 GMT" }, { "version": "v2", "created": "Tue, 21 Mar 2017 13:08:49 GMT" } ]
2017-03-22T00:00:00
[ [ "Reinbacher", "Christian", "" ], [ "Munda", "Gottfried", "" ], [ "Pock", "Thomas", "" ] ]
TITLE: Real-Time Panoramic Tracking for Event Cameras ABSTRACT: Event cameras are a paradigm shift in camera technology. Instead of full frames, the sensor captures a sparse set of events caused by intensity changes. Since only the changes are transferred, those cameras are able to capture quick movements of objects in the scene or of the camera itself. In this work we propose a novel method to perform camera tracking of event cameras in a panoramic setting with three degrees of freedom. We propose a direct camera tracking formulation, similar to state-of-the-art in visual odometry. We show that the minimal information needed for simultaneous tracking and mapping is the spatial position of events, without using the appearance of the imaged scene point. We verify the robustness to fast camera movements and dynamic objects in the scene on a recently proposed dataset and self-recorded sequences.
new_dataset
0.956594
1703.06585
Abhishek Das
Abhishek Das, Satwik Kottur, Jos\'e M. F. Moura, Stefan Lee, Dhruv Batra
Learning Cooperative Visual Dialog Agents with Deep Reinforcement Learning
11 pages, 4 figures, 2 tables, webpage: http://visualdialog.org/
null
null
null
cs.CV cs.AI cs.CL cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We introduce the first goal-driven training for visual question answering and dialog agents. Specifically, we pose a cooperative 'image guessing' game between two agents -- Qbot and Abot -- who communicate in natural language dialog so that Qbot can select an unseen image from a lineup of images. We use deep reinforcement learning (RL) to learn the policies of these agents end-to-end -- from pixels to multi-agent multi-round dialog to game reward. We demonstrate two experimental results. First, as a 'sanity check' demonstration of pure RL (from scratch), we show results on a synthetic world, where the agents communicate in ungrounded vocabulary, i.e., symbols with no pre-specified meanings (X, Y, Z). We find that two bots invent their own communication protocol and start using certain symbols to ask/answer about certain visual attributes (shape/color/style). Thus, we demonstrate the emergence of grounded language and communication among 'visual' dialog agents with no human supervision. Second, we conduct large-scale real-image experiments on the VisDial dataset, where we pretrain with supervised dialog data and show that the RL 'fine-tuned' agents significantly outperform SL agents. Interestingly, the RL Qbot learns to ask questions that Abot is good at, ultimately resulting in more informative dialog and a better team.
[ { "version": "v1", "created": "Mon, 20 Mar 2017 03:50:57 GMT" }, { "version": "v2", "created": "Tue, 21 Mar 2017 17:41:23 GMT" } ]
2017-03-22T00:00:00
[ [ "Das", "Abhishek", "" ], [ "Kottur", "Satwik", "" ], [ "Moura", "José M. F.", "" ], [ "Lee", "Stefan", "" ], [ "Batra", "Dhruv", "" ] ]
TITLE: Learning Cooperative Visual Dialog Agents with Deep Reinforcement Learning ABSTRACT: We introduce the first goal-driven training for visual question answering and dialog agents. Specifically, we pose a cooperative 'image guessing' game between two agents -- Qbot and Abot -- who communicate in natural language dialog so that Qbot can select an unseen image from a lineup of images. We use deep reinforcement learning (RL) to learn the policies of these agents end-to-end -- from pixels to multi-agent multi-round dialog to game reward. We demonstrate two experimental results. First, as a 'sanity check' demonstration of pure RL (from scratch), we show results on a synthetic world, where the agents communicate in ungrounded vocabulary, i.e., symbols with no pre-specified meanings (X, Y, Z). We find that two bots invent their own communication protocol and start using certain symbols to ask/answer about certain visual attributes (shape/color/style). Thus, we demonstrate the emergence of grounded language and communication among 'visual' dialog agents with no human supervision. Second, we conduct large-scale real-image experiments on the VisDial dataset, where we pretrain with supervised dialog data and show that the RL 'fine-tuned' agents significantly outperform SL agents. Interestingly, the RL Qbot learns to ask questions that Abot is good at, ultimately resulting in more informative dialog and a better team.
no_new_dataset
0.939969
1703.06902
Juncheng Li
Juncheng Li, Wei Dai, Florian Metze, Shuhui Qu, Samarjit Das
A Comparison of deep learning methods for environmental sound
5 pages including reference
published at ICASSP 2017
null
null
cs.SD cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Environmental sound detection is a challenging application of machine learning because of the noisy nature of the signal, and the small amount of (labeled) data that is typically available. This work thus presents a comparison of several state-of-the-art Deep Learning models on the IEEE challenge on Detection and Classification of Acoustic Scenes and Events (DCASE) 2016 challenge task and data, classifying sounds into one of fifteen common indoor and outdoor acoustic scenes, such as bus, cafe, car, city center, forest path, library, train, etc. In total, 13 hours of stereo audio recordings are available, making this one of the largest datasets available. We perform experiments on six sets of features, including standard Mel-frequency cepstral coefficients (MFCC), Binaural MFCC, log Mel-spectrum and two different large- scale temporal pooling features extracted using OpenSMILE. On these features, we apply five models: Gaussian Mixture Model (GMM), Deep Neural Network (DNN), Recurrent Neural Network (RNN), Convolutional Deep Neural Net- work (CNN) and i-vector. Using the late-fusion approach, we improve the performance of the baseline 72.5% by 15.6% in 4-fold Cross Validation (CV) avg. accuracy and 11% in test accuracy, which matches the best result of the DCASE 2016 challenge. With large feature sets, deep neural network models out- perform traditional methods and achieve the best performance among all the studied methods. Consistent with other work, the best performing single model is the non-temporal DNN model, which we take as evidence that sounds in the DCASE challenge do not exhibit strong temporal dynamics.
[ { "version": "v1", "created": "Mon, 20 Mar 2017 18:11:47 GMT" } ]
2017-03-22T00:00:00
[ [ "Li", "Juncheng", "" ], [ "Dai", "Wei", "" ], [ "Metze", "Florian", "" ], [ "Qu", "Shuhui", "" ], [ "Das", "Samarjit", "" ] ]
TITLE: A Comparison of deep learning methods for environmental sound ABSTRACT: Environmental sound detection is a challenging application of machine learning because of the noisy nature of the signal, and the small amount of (labeled) data that is typically available. This work thus presents a comparison of several state-of-the-art Deep Learning models on the IEEE challenge on Detection and Classification of Acoustic Scenes and Events (DCASE) 2016 challenge task and data, classifying sounds into one of fifteen common indoor and outdoor acoustic scenes, such as bus, cafe, car, city center, forest path, library, train, etc. In total, 13 hours of stereo audio recordings are available, making this one of the largest datasets available. We perform experiments on six sets of features, including standard Mel-frequency cepstral coefficients (MFCC), Binaural MFCC, log Mel-spectrum and two different large- scale temporal pooling features extracted using OpenSMILE. On these features, we apply five models: Gaussian Mixture Model (GMM), Deep Neural Network (DNN), Recurrent Neural Network (RNN), Convolutional Deep Neural Net- work (CNN) and i-vector. Using the late-fusion approach, we improve the performance of the baseline 72.5% by 15.6% in 4-fold Cross Validation (CV) avg. accuracy and 11% in test accuracy, which matches the best result of the DCASE 2016 challenge. With large feature sets, deep neural network models out- perform traditional methods and achieve the best performance among all the studied methods. Consistent with other work, the best performing single model is the non-temporal DNN model, which we take as evidence that sounds in the DCASE challenge do not exhibit strong temporal dynamics.
no_new_dataset
0.946794
1703.07004
Marzyeh Ghassemi
Harini Suresh, Peter Szolovits, Marzyeh Ghassemi
The Use of Autoencoders for Discovering Patient Phenotypes
null
NIPS Workshop on Machine Learning for Healthcare (NIPS ML4HC) 2016
null
null
cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We use autoencoders to create low-dimensional embeddings of underlying patient phenotypes that we hypothesize are a governing factor in determining how different patients will react to different interventions. We compare the performance of autoencoders that take fixed length sequences of concatenated timesteps as input with a recurrent sequence-to-sequence autoencoder. We evaluate our methods on around 35,500 patients from the latest MIMIC III dataset from Beth Israel Deaconess Hospital.
[ { "version": "v1", "created": "Mon, 20 Mar 2017 23:30:40 GMT" } ]
2017-03-22T00:00:00
[ [ "Suresh", "Harini", "" ], [ "Szolovits", "Peter", "" ], [ "Ghassemi", "Marzyeh", "" ] ]
TITLE: The Use of Autoencoders for Discovering Patient Phenotypes ABSTRACT: We use autoencoders to create low-dimensional embeddings of underlying patient phenotypes that we hypothesize are a governing factor in determining how different patients will react to different interventions. We compare the performance of autoencoders that take fixed length sequences of concatenated timesteps as input with a recurrent sequence-to-sequence autoencoder. We evaluate our methods on around 35,500 patients from the latest MIMIC III dataset from Beth Israel Deaconess Hospital.
no_new_dataset
0.945651
1703.07090
Jun Zhang
Xu Tian, Jun Zhang, Zejun Ma, Yi He, Juan Wei, Peihao Wu, Wenchang Situ, Shuai Li, Yang Zhang
Deep LSTM for Large Vocabulary Continuous Speech Recognition
8 pages. arXiv admin note: text overlap with arXiv:1703.01024
null
null
null
cs.CL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recurrent neural networks (RNNs), especially long short-term memory (LSTM) RNNs, are effective network for sequential task like speech recognition. Deeper LSTM models perform well on large vocabulary continuous speech recognition, because of their impressive learning ability. However, it is more difficult to train a deeper network. We introduce a training framework with layer-wise training and exponential moving average methods for deeper LSTM models. It is a competitive framework that LSTM models of more than 7 layers are successfully trained on Shenma voice search data in Mandarin and they outperform the deep LSTM models trained by conventional approach. Moreover, in order for online streaming speech recognition applications, the shallow model with low real time factor is distilled from the very deep model. The recognition accuracy have little loss in the distillation process. Therefore, the model trained with the proposed training framework reduces relative 14\% character error rate, compared to original model which has the similar real-time capability. Furthermore, the novel transfer learning strategy with segmental Minimum Bayes-Risk is also introduced in the framework. The strategy makes it possible that training with only a small part of dataset could outperform full dataset training from the beginning.
[ { "version": "v1", "created": "Tue, 21 Mar 2017 08:24:50 GMT" } ]
2017-03-22T00:00:00
[ [ "Tian", "Xu", "" ], [ "Zhang", "Jun", "" ], [ "Ma", "Zejun", "" ], [ "He", "Yi", "" ], [ "Wei", "Juan", "" ], [ "Wu", "Peihao", "" ], [ "Situ", "Wenchang", "" ], [ "Li", "Shuai", "" ], [ "Zhang", "Yang", "" ] ]
TITLE: Deep LSTM for Large Vocabulary Continuous Speech Recognition ABSTRACT: Recurrent neural networks (RNNs), especially long short-term memory (LSTM) RNNs, are effective network for sequential task like speech recognition. Deeper LSTM models perform well on large vocabulary continuous speech recognition, because of their impressive learning ability. However, it is more difficult to train a deeper network. We introduce a training framework with layer-wise training and exponential moving average methods for deeper LSTM models. It is a competitive framework that LSTM models of more than 7 layers are successfully trained on Shenma voice search data in Mandarin and they outperform the deep LSTM models trained by conventional approach. Moreover, in order for online streaming speech recognition applications, the shallow model with low real time factor is distilled from the very deep model. The recognition accuracy have little loss in the distillation process. Therefore, the model trained with the proposed training framework reduces relative 14\% character error rate, compared to original model which has the similar real-time capability. Furthermore, the novel transfer learning strategy with segmental Minimum Bayes-Risk is also introduced in the framework. The strategy makes it possible that training with only a small part of dataset could outperform full dataset training from the beginning.
no_new_dataset
0.952042
1703.07115
Mandar Kulkarni Mr.
Mandar Kulkarni, Shirish Karande
Layer-wise training of deep networks using kernel similarity
null
Deep Learning for Pattern Recognition (DLPR) workshop at ICPR 2016
null
null
cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Deep learning has shown promising results in many machine learning applications. The hierarchical feature representation built by deep networks enable compact and precise encoding of the data. A kernel analysis of the trained deep networks demonstrated that with deeper layers, more simple and more accurate data representations are obtained. In this paper, we propose an approach for layer-wise training of a deep network for the supervised classification task. A transformation matrix of each layer is obtained by solving an optimization aimed at a better representation where a subsequent layer builds its representation on the top of the features produced by a previous layer. We compared the performance of our approach with a DNN trained using back-propagation which has same architecture as ours. Experimental results on the real image datasets demonstrate efficacy of our approach. We also performed kernel analysis of layer representations to validate the claim of better feature encoding.
[ { "version": "v1", "created": "Tue, 21 Mar 2017 09:53:51 GMT" } ]
2017-03-22T00:00:00
[ [ "Kulkarni", "Mandar", "" ], [ "Karande", "Shirish", "" ] ]
TITLE: Layer-wise training of deep networks using kernel similarity ABSTRACT: Deep learning has shown promising results in many machine learning applications. The hierarchical feature representation built by deep networks enable compact and precise encoding of the data. A kernel analysis of the trained deep networks demonstrated that with deeper layers, more simple and more accurate data representations are obtained. In this paper, we propose an approach for layer-wise training of a deep network for the supervised classification task. A transformation matrix of each layer is obtained by solving an optimization aimed at a better representation where a subsequent layer builds its representation on the top of the features produced by a previous layer. We compared the performance of our approach with a DNN trained using back-propagation which has same architecture as ours. Experimental results on the real image datasets demonstrate efficacy of our approach. We also performed kernel analysis of layer representations to validate the claim of better feature encoding.
no_new_dataset
0.951953
1703.07131
Mandar Kulkarni Mr.
Mandar Kulkarni, Kalpesh Patil, Shirish Karande
Knowledge distillation using unlabeled mismatched images
null
null
null
null
cs.CV cs.LG stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Current approaches for Knowledge Distillation (KD) either directly use training data or sample from the training data distribution. In this paper, we demonstrate effectiveness of 'mismatched' unlabeled stimulus to perform KD for image classification networks. For illustration, we consider scenarios where this is a complete absence of training data, or mismatched stimulus has to be used for augmenting a small amount of training data. We demonstrate that stimulus complexity is a key factor for distillation's good performance. Our examples include use of various datasets for stimulating MNIST and CIFAR teachers.
[ { "version": "v1", "created": "Tue, 21 Mar 2017 10:34:59 GMT" } ]
2017-03-22T00:00:00
[ [ "Kulkarni", "Mandar", "" ], [ "Patil", "Kalpesh", "" ], [ "Karande", "Shirish", "" ] ]
TITLE: Knowledge distillation using unlabeled mismatched images ABSTRACT: Current approaches for Knowledge Distillation (KD) either directly use training data or sample from the training data distribution. In this paper, we demonstrate effectiveness of 'mismatched' unlabeled stimulus to perform KD for image classification networks. For illustration, we consider scenarios where this is a complete absence of training data, or mismatched stimulus has to be used for augmenting a small amount of training data. We demonstrate that stimulus complexity is a key factor for distillation's good performance. Our examples include use of various datasets for stimulating MNIST and CIFAR teachers.
no_new_dataset
0.950549
1703.07144
Bumsub Ham
Bumsub Ham, Minsu Cho, Cordelia Schmid, Jean Ponce
Proposal Flow: Semantic Correspondences from Object Proposals
arXiv admin note: text overlap with arXiv:1511.05065
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Finding image correspondences remains a challenging problem in the presence of intra-class variations and large changes in scene layout. Semantic flow methods are designed to handle images depicting different instances of the same object or scene category. We introduce a novel approach to semantic flow, dubbed proposal flow, that establishes reliable correspondences using object proposals. Unlike prevailing semantic flow approaches that operate on pixels or regularly sampled local regions, proposal flow benefits from the characteristics of modern object proposals, that exhibit high repeatability at multiple scales, and can take advantage of both local and geometric consistency constraints among proposals. We also show that the corresponding sparse proposal flow can effectively be transformed into a conventional dense flow field. We introduce two new challenging datasets that can be used to evaluate both general semantic flow techniques and region-based approaches such as proposal flow. We use these benchmarks to compare different matching algorithms, object proposals, and region features within proposal flow, to the state of the art in semantic flow. This comparison, along with experiments on standard datasets, demonstrates that proposal flow significantly outperforms existing semantic flow methods in various settings.
[ { "version": "v1", "created": "Tue, 21 Mar 2017 10:57:27 GMT" } ]
2017-03-22T00:00:00
[ [ "Ham", "Bumsub", "" ], [ "Cho", "Minsu", "" ], [ "Schmid", "Cordelia", "" ], [ "Ponce", "Jean", "" ] ]
TITLE: Proposal Flow: Semantic Correspondences from Object Proposals ABSTRACT: Finding image correspondences remains a challenging problem in the presence of intra-class variations and large changes in scene layout. Semantic flow methods are designed to handle images depicting different instances of the same object or scene category. We introduce a novel approach to semantic flow, dubbed proposal flow, that establishes reliable correspondences using object proposals. Unlike prevailing semantic flow approaches that operate on pixels or regularly sampled local regions, proposal flow benefits from the characteristics of modern object proposals, that exhibit high repeatability at multiple scales, and can take advantage of both local and geometric consistency constraints among proposals. We also show that the corresponding sparse proposal flow can effectively be transformed into a conventional dense flow field. We introduce two new challenging datasets that can be used to evaluate both general semantic flow techniques and region-based approaches such as proposal flow. We use these benchmarks to compare different matching algorithms, object proposals, and region features within proposal flow, to the state of the art in semantic flow. This comparison, along with experiments on standard datasets, demonstrates that proposal flow significantly outperforms existing semantic flow methods in various settings.
new_dataset
0.958187
1703.07334
Shichao Yang
Shichao Yang, Yu Song, Michael Kaess, Sebastian Scherer
Pop-up SLAM: Semantic Monocular Plane SLAM for Low-texture Environments
International Conference on Intelligent Robots and Systems (IROS) 2016
null
null
null
cs.CV cs.RO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Existing simultaneous localization and mapping (SLAM) algorithms are not robust in challenging low-texture environments because there are only few salient features. The resulting sparse or semi-dense map also conveys little information for motion planning. Though some work utilize plane or scene layout for dense map regularization, they require decent state estimation from other sources. In this paper, we propose real-time monocular plane SLAM to demonstrate that scene understanding could improve both state estimation and dense mapping especially in low-texture environments. The plane measurements come from a pop-up 3D plane model applied to each single image. We also combine planes with point based SLAM to improve robustness. On a public TUM dataset, our algorithm generates a dense semantic 3D model with pixel depth error of 6.2 cm while existing SLAM algorithms fail. On a 60 m long dataset with loops, our method creates a much better 3D model with state estimation error of 0.67%.
[ { "version": "v1", "created": "Tue, 21 Mar 2017 17:41:46 GMT" } ]
2017-03-22T00:00:00
[ [ "Yang", "Shichao", "" ], [ "Song", "Yu", "" ], [ "Kaess", "Michael", "" ], [ "Scherer", "Sebastian", "" ] ]
TITLE: Pop-up SLAM: Semantic Monocular Plane SLAM for Low-texture Environments ABSTRACT: Existing simultaneous localization and mapping (SLAM) algorithms are not robust in challenging low-texture environments because there are only few salient features. The resulting sparse or semi-dense map also conveys little information for motion planning. Though some work utilize plane or scene layout for dense map regularization, they require decent state estimation from other sources. In this paper, we propose real-time monocular plane SLAM to demonstrate that scene understanding could improve both state estimation and dense mapping especially in low-texture environments. The plane measurements come from a pop-up 3D plane model applied to each single image. We also combine planes with point based SLAM to improve robustness. On a public TUM dataset, our algorithm generates a dense semantic 3D model with pixel depth error of 6.2 cm while existing SLAM algorithms fail. On a 60 m long dataset with loops, our method creates a much better 3D model with state estimation error of 0.67%.
no_new_dataset
0.951459
1511.03376
Yue Wang
Yue Wang and Jaewoo Lee and Daniel Kifer
Revisiting Differentially Private Hypothesis Tests for Categorical Data
null
null
null
null
cs.CR stat.ME
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we consider methods for performing hypothesis tests on data protected by a statistical disclosure control technology known as differential privacy. Previous approaches to differentially private hypothesis testing either perturbed the test statistic with random noise having large variance (and resulted in a significant loss of power) or added smaller amounts of noise directly to the data but failed to adjust the test in response to the added noise (resulting in biased, unreliable $p$-values). In this paper, we develop a variety of practical hypothesis tests that address these problems. Using a different asymptotic regime that is more suited to hypothesis testing with privacy, we show a modified equivalence between chi-squared tests and likelihood ratio tests. We then develop differentially private likelihood ratio and chi-squared tests for a variety of applications on tabular data (i.e., independence, sample proportions, and goodness-of-fit tests). Experimental evaluations on small and large datasets using a wide variety of privacy settings demonstrate the practicality and reliability of our methods.
[ { "version": "v1", "created": "Wed, 11 Nov 2015 03:36:38 GMT" }, { "version": "v2", "created": "Sat, 13 Feb 2016 03:19:19 GMT" }, { "version": "v3", "created": "Fri, 2 Dec 2016 04:09:27 GMT" }, { "version": "v4", "created": "Sat, 18 Mar 2017 06:55:30 GMT" } ]
2017-03-21T00:00:00
[ [ "Wang", "Yue", "" ], [ "Lee", "Jaewoo", "" ], [ "Kifer", "Daniel", "" ] ]
TITLE: Revisiting Differentially Private Hypothesis Tests for Categorical Data ABSTRACT: In this paper, we consider methods for performing hypothesis tests on data protected by a statistical disclosure control technology known as differential privacy. Previous approaches to differentially private hypothesis testing either perturbed the test statistic with random noise having large variance (and resulted in a significant loss of power) or added smaller amounts of noise directly to the data but failed to adjust the test in response to the added noise (resulting in biased, unreliable $p$-values). In this paper, we develop a variety of practical hypothesis tests that address these problems. Using a different asymptotic regime that is more suited to hypothesis testing with privacy, we show a modified equivalence between chi-squared tests and likelihood ratio tests. We then develop differentially private likelihood ratio and chi-squared tests for a variety of applications on tabular data (i.e., independence, sample proportions, and goodness-of-fit tests). Experimental evaluations on small and large datasets using a wide variety of privacy settings demonstrate the practicality and reliability of our methods.
no_new_dataset
0.953837
1606.02185
Harrison Edwards
Harrison Edwards, Amos Storkey
Towards a Neural Statistician
Updated to camera ready version for ICLR 2017
null
null
null
stat.ML cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
An efficient learner is one who reuses what they already know to tackle a new problem. For a machine learner, this means understanding the similarities amongst datasets. In order to do this, one must take seriously the idea of working with datasets, rather than datapoints, as the key objects to model. Towards this goal, we demonstrate an extension of a variational autoencoder that can learn a method for computing representations, or statistics, of datasets in an unsupervised fashion. The network is trained to produce statistics that encapsulate a generative model for each dataset. Hence the network enables efficient learning from new datasets for both unsupervised and supervised tasks. We show that we are able to learn statistics that can be used for: clustering datasets, transferring generative models to new datasets, selecting representative samples of datasets and classifying previously unseen classes. We refer to our model as a neural statistician, and by this we mean a neural network that can learn to compute summary statistics of datasets without supervision.
[ { "version": "v1", "created": "Tue, 7 Jun 2016 15:36:39 GMT" }, { "version": "v2", "created": "Mon, 20 Mar 2017 17:18:16 GMT" } ]
2017-03-21T00:00:00
[ [ "Edwards", "Harrison", "" ], [ "Storkey", "Amos", "" ] ]
TITLE: Towards a Neural Statistician ABSTRACT: An efficient learner is one who reuses what they already know to tackle a new problem. For a machine learner, this means understanding the similarities amongst datasets. In order to do this, one must take seriously the idea of working with datasets, rather than datapoints, as the key objects to model. Towards this goal, we demonstrate an extension of a variational autoencoder that can learn a method for computing representations, or statistics, of datasets in an unsupervised fashion. The network is trained to produce statistics that encapsulate a generative model for each dataset. Hence the network enables efficient learning from new datasets for both unsupervised and supervised tasks. We show that we are able to learn statistics that can be used for: clustering datasets, transferring generative models to new datasets, selecting representative samples of datasets and classifying previously unseen classes. We refer to our model as a neural statistician, and by this we mean a neural network that can learn to compute summary statistics of datasets without supervision.
no_new_dataset
0.946001
1609.09747
Antoine Deleforge
Saurabh Kataria (IIT Kanpur, Panama), Cl\'ement Gaultier (Panama), Antoine Deleforge (Panama)
Hearing in a shoe-box : binaural source position and wall absorption estimation using virtually supervised learning
2017 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP), Mar 2017, New-Orleans, United States
null
null
hal-01372435
cs.SD
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper introduces a new framework for supervised sound source localization referred to as virtually-supervised learning. An acoustic shoe-box room simulator is used to generate a large number of binaural single-source audio scenes. These scenes are used to build a dataset of spatial binaural features annotated with acoustic properties such as the 3D source position and the walls' absorption coefficients. A probabilistic high- to low-dimensional regression framework is used to learn a mapping from these features to the acoustic properties. Results indicate that this mapping successfully estimates the azimuth and elevation of new sources, but also their range and even the walls' absorption coefficients solely based on binaural signals. Results also reveal that incorporating random-diffusion effects in the data significantly improves the estimation of all parameters.
[ { "version": "v1", "created": "Fri, 30 Sep 2016 14:20:56 GMT" }, { "version": "v2", "created": "Mon, 20 Mar 2017 13:39:49 GMT" } ]
2017-03-21T00:00:00
[ [ "Kataria", "Saurabh", "", "IIT Kanpur, Panama" ], [ "Gaultier", "Clément", "", "Panama" ], [ "Deleforge", "Antoine", "", "Panama" ] ]
TITLE: Hearing in a shoe-box : binaural source position and wall absorption estimation using virtually supervised learning ABSTRACT: This paper introduces a new framework for supervised sound source localization referred to as virtually-supervised learning. An acoustic shoe-box room simulator is used to generate a large number of binaural single-source audio scenes. These scenes are used to build a dataset of spatial binaural features annotated with acoustic properties such as the 3D source position and the walls' absorption coefficients. A probabilistic high- to low-dimensional regression framework is used to learn a mapping from these features to the acoustic properties. Results indicate that this mapping successfully estimates the azimuth and elevation of new sources, but also their range and even the walls' absorption coefficients solely based on binaural signals. Results also reveal that incorporating random-diffusion effects in the data significantly improves the estimation of all parameters.
no_new_dataset
0.809276
1611.01436
Tom Kwiatkowski
Kenton Lee, Shimi Salant, Tom Kwiatkowski, Ankur Parikh, Dipanjan Das, Jonathan Berant
Learning Recurrent Span Representations for Extractive Question Answering
null
null
null
null
cs.CL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The reading comprehension task, that asks questions about a given evidence document, is a central problem in natural language understanding. Recent formulations of this task have typically focused on answer selection from a set of candidates pre-defined manually or through the use of an external NLP pipeline. However, Rajpurkar et al. (2016) recently released the SQuAD dataset in which the answers can be arbitrary strings from the supplied text. In this paper, we focus on this answer extraction task, presenting a novel model architecture that efficiently builds fixed length representations of all spans in the evidence document with a recurrent network. We show that scoring explicit span representations significantly improves performance over other approaches that factor the prediction into separate predictions about words or start and end markers. Our approach improves upon the best published results of Wang & Jiang (2016) by 5% and decreases the error of Rajpurkar et al.'s baseline by > 50%.
[ { "version": "v1", "created": "Fri, 4 Nov 2016 16:12:46 GMT" }, { "version": "v2", "created": "Fri, 17 Mar 2017 18:11:12 GMT" } ]
2017-03-21T00:00:00
[ [ "Lee", "Kenton", "" ], [ "Salant", "Shimi", "" ], [ "Kwiatkowski", "Tom", "" ], [ "Parikh", "Ankur", "" ], [ "Das", "Dipanjan", "" ], [ "Berant", "Jonathan", "" ] ]
TITLE: Learning Recurrent Span Representations for Extractive Question Answering ABSTRACT: The reading comprehension task, that asks questions about a given evidence document, is a central problem in natural language understanding. Recent formulations of this task have typically focused on answer selection from a set of candidates pre-defined manually or through the use of an external NLP pipeline. However, Rajpurkar et al. (2016) recently released the SQuAD dataset in which the answers can be arbitrary strings from the supplied text. In this paper, we focus on this answer extraction task, presenting a novel model architecture that efficiently builds fixed length representations of all spans in the evidence document with a recurrent network. We show that scoring explicit span representations significantly improves performance over other approaches that factor the prediction into separate predictions about words or start and end markers. Our approach improves upon the best published results of Wang & Jiang (2016) by 5% and decreases the error of Rajpurkar et al.'s baseline by > 50%.
new_dataset
0.961461
1611.01560
R\'obert Beck
R\'obert Beck, L\'aszl\'o Dobos, Tam\'as Budav\'ari, Alexander S. Szalay, Istv\'an Csabai
Photo-z-SQL: integrated, flexible photometric redshift computation in a database
14 pages, 5 figures. Minor revision accepted by Astronomy & Computing on 2017 March 11
null
10.1016/j.ascom.2017.03.002
null
astro-ph.GA astro-ph.IM cs.DB
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a flexible template-based photometric redshift estimation framework, implemented in C#, that can be seamlessly integrated into a SQL database (or DB) server and executed on-demand in SQL. The DB integration eliminates the need to move large photometric datasets outside a database for redshift estimation, and utilizes the computational capabilities of DB hardware. The code is able to perform both maximum likelihood and Bayesian estimation, and can handle inputs of variable photometric filter sets and corresponding broad-band magnitudes. It is possible to take into account the full covariance matrix between filters, and filter zero points can be empirically calibrated using measurements with given redshifts. The list of spectral templates and the prior can be specified flexibly, and the expensive synthetic magnitude computations are done via lazy evaluation, coupled with a caching of results. Parallel execution is fully supported. For large upcoming photometric surveys such as the LSST, the ability to perform in-place photo-z calculation would be a significant advantage. Also, the efficient handling of variable filter sets is a necessity for heterogeneous databases, for example the Hubble Source Catalog, and for cross-match services such as SkyQuery. We illustrate the performance of our code on two reference photo-z estimation testing datasets, and provide an analysis of execution time and scalability with respect to different configurations. The code is available for download at https://github.com/beckrob/Photo-z-SQL.
[ { "version": "v1", "created": "Fri, 4 Nov 2016 22:48:06 GMT" }, { "version": "v2", "created": "Mon, 20 Mar 2017 11:46:57 GMT" } ]
2017-03-21T00:00:00
[ [ "Beck", "Róbert", "" ], [ "Dobos", "László", "" ], [ "Budavári", "Tamás", "" ], [ "Szalay", "Alexander S.", "" ], [ "Csabai", "István", "" ] ]
TITLE: Photo-z-SQL: integrated, flexible photometric redshift computation in a database ABSTRACT: We present a flexible template-based photometric redshift estimation framework, implemented in C#, that can be seamlessly integrated into a SQL database (or DB) server and executed on-demand in SQL. The DB integration eliminates the need to move large photometric datasets outside a database for redshift estimation, and utilizes the computational capabilities of DB hardware. The code is able to perform both maximum likelihood and Bayesian estimation, and can handle inputs of variable photometric filter sets and corresponding broad-band magnitudes. It is possible to take into account the full covariance matrix between filters, and filter zero points can be empirically calibrated using measurements with given redshifts. The list of spectral templates and the prior can be specified flexibly, and the expensive synthetic magnitude computations are done via lazy evaluation, coupled with a caching of results. Parallel execution is fully supported. For large upcoming photometric surveys such as the LSST, the ability to perform in-place photo-z calculation would be a significant advantage. Also, the efficient handling of variable filter sets is a necessity for heterogeneous databases, for example the Hubble Source Catalog, and for cross-match services such as SkyQuery. We illustrate the performance of our code on two reference photo-z estimation testing datasets, and provide an analysis of execution time and scalability with respect to different configurations. The code is available for download at https://github.com/beckrob/Photo-z-SQL.
no_new_dataset
0.945751
1611.05216
Yemin Shi Shi
Yemin Shi and Yonghong Tian and Yaowei Wang and Tiejun Huang
Learning long-term dependencies for action recognition with a biologically-inspired deep network
9 pages, 4 figures
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Despite a lot of research efforts devoted in recent years, how to efficiently learn long-term dependencies from sequences still remains a pretty challenging task. As one of the key models for sequence learning, recurrent neural network (RNN) and its variants such as long short term memory (LSTM) and gated recurrent unit (GRU) are still not powerful enough in practice. One possible reason is that they have only feedforward connections, which is different from the biological neural system that is typically composed of both feedforward and feedback connections. To address this problem, this paper proposes a biologically-inspired deep network, called shuttleNet\footnote{Our code is available at \url{https://github.com/shiyemin/shuttlenet}}. Technologically, the shuttleNet consists of several processors, each of which is a GRU while associated with multiple groups of cells and states. Unlike traditional RNNs, all processors inside shuttleNet are loop connected to mimic the brain's feedforward and feedback connections, in which they are shared across multiple pathways in the loop connection. Attention mechanism is then employed to select the best information flow pathway. Extensive experiments conducted on two benchmark datasets (i.e UCF101 and HMDB51) show that we can beat state-of-the-art methods by simply embedding shuttleNet into a CNN-RNN framework.
[ { "version": "v1", "created": "Wed, 16 Nov 2016 10:49:43 GMT" }, { "version": "v2", "created": "Thu, 16 Mar 2017 15:55:14 GMT" }, { "version": "v3", "created": "Sun, 19 Mar 2017 08:27:24 GMT" } ]
2017-03-21T00:00:00
[ [ "Shi", "Yemin", "" ], [ "Tian", "Yonghong", "" ], [ "Wang", "Yaowei", "" ], [ "Huang", "Tiejun", "" ] ]
TITLE: Learning long-term dependencies for action recognition with a biologically-inspired deep network ABSTRACT: Despite a lot of research efforts devoted in recent years, how to efficiently learn long-term dependencies from sequences still remains a pretty challenging task. As one of the key models for sequence learning, recurrent neural network (RNN) and its variants such as long short term memory (LSTM) and gated recurrent unit (GRU) are still not powerful enough in practice. One possible reason is that they have only feedforward connections, which is different from the biological neural system that is typically composed of both feedforward and feedback connections. To address this problem, this paper proposes a biologically-inspired deep network, called shuttleNet\footnote{Our code is available at \url{https://github.com/shiyemin/shuttlenet}}. Technologically, the shuttleNet consists of several processors, each of which is a GRU while associated with multiple groups of cells and states. Unlike traditional RNNs, all processors inside shuttleNet are loop connected to mimic the brain's feedforward and feedback connections, in which they are shared across multiple pathways in the loop connection. Attention mechanism is then employed to select the best information flow pathway. Extensive experiments conducted on two benchmark datasets (i.e UCF101 and HMDB51) show that we can beat state-of-the-art methods by simply embedding shuttleNet into a CNN-RNN framework.
no_new_dataset
0.943712
1611.06013
Kui Jia
Kui Jia
Improving training of deep neural networks via Singular Value Bounding
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Deep learning methods achieve great success recently on many computer vision problems, with image classification and object detection as the prominent examples. In spite of these practical successes, optimization of deep networks remains an active topic in deep learning research. In this work, we focus on investigation of the network solution properties that can potentially lead to good performance. Our research is inspired by theoretical and empirical results that use orthogonal matrices to initialize networks, but we are interested in investigating how orthogonal weight matrices perform when network training converges. To this end, we propose to constrain the solutions of weight matrices in the orthogonal feasible set during the whole process of network training, and achieve this by a simple yet effective method called Singular Value Bounding (SVB). In SVB, all singular values of each weight matrix are simply bounded in a narrow band around the value of 1. Based on the same motivation, we also propose Bounded Batch Normalization (BBN), which improves Batch Normalization by removing its potential risk of ill-conditioned layer transform. We present both theoretical and empirical results to justify our proposed methods. Experiments on benchmark image classification datasets show the efficacy of our proposed SVB and BBN. In particular, we achieve the state-of-the-art results of 3.06% error rate on CIFAR10 and 16.90% on CIFAR100, using off-the-shelf network architectures (Wide ResNets). Our preliminary results on ImageNet also show the promise in large-scale learning.
[ { "version": "v1", "created": "Fri, 18 Nov 2016 09:09:56 GMT" }, { "version": "v2", "created": "Tue, 29 Nov 2016 09:49:11 GMT" }, { "version": "v3", "created": "Sat, 18 Mar 2017 07:27:09 GMT" } ]
2017-03-21T00:00:00
[ [ "Jia", "Kui", "" ] ]
TITLE: Improving training of deep neural networks via Singular Value Bounding ABSTRACT: Deep learning methods achieve great success recently on many computer vision problems, with image classification and object detection as the prominent examples. In spite of these practical successes, optimization of deep networks remains an active topic in deep learning research. In this work, we focus on investigation of the network solution properties that can potentially lead to good performance. Our research is inspired by theoretical and empirical results that use orthogonal matrices to initialize networks, but we are interested in investigating how orthogonal weight matrices perform when network training converges. To this end, we propose to constrain the solutions of weight matrices in the orthogonal feasible set during the whole process of network training, and achieve this by a simple yet effective method called Singular Value Bounding (SVB). In SVB, all singular values of each weight matrix are simply bounded in a narrow band around the value of 1. Based on the same motivation, we also propose Bounded Batch Normalization (BBN), which improves Batch Normalization by removing its potential risk of ill-conditioned layer transform. We present both theoretical and empirical results to justify our proposed methods. Experiments on benchmark image classification datasets show the efficacy of our proposed SVB and BBN. In particular, we achieve the state-of-the-art results of 3.06% error rate on CIFAR10 and 16.90% on CIFAR100, using off-the-shelf network architectures (Wide ResNets). Our preliminary results on ImageNet also show the promise in large-scale learning.
no_new_dataset
0.946941
1611.09340
Adriana Romero
Adriana Romero, Pierre Luc Carrier, Akram Erraqabi, Tristan Sylvain, Alex Auvolat, Etienne Dejoie, Marc-Andr\'e Legault, Marie-Pierre Dub\'e, Julie G. Hussin, Yoshua Bengio
Diet Networks: Thin Parameters for Fat Genomics
null
ICLR 2017
null
null
cs.LG stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Learning tasks such as those involving genomic data often poses a serious challenge: the number of input features can be orders of magnitude larger than the number of training examples, making it difficult to avoid overfitting, even when using the known regularization techniques. We focus here on tasks in which the input is a description of the genetic variation specific to a patient, the single nucleotide polymorphisms (SNPs), yielding millions of ternary inputs. Improving the ability of deep learning to handle such datasets could have an important impact in precision medicine, where high-dimensional data regarding a particular patient is used to make predictions of interest. Even though the amount of data for such tasks is increasing, this mismatch between the number of examples and the number of inputs remains a concern. Naive implementations of classifier neural networks involve a huge number of free parameters in their first layer: each input feature is associated with as many parameters as there are hidden units. We propose a novel neural network parametrization which considerably reduces the number of free parameters. It is based on the idea that we can first learn or provide a distributed representation for each input feature (e.g. for each position in the genome where variations are observed), and then learn (with another neural network called the parameter prediction network) how to map a feature's distributed representation to the vector of parameters specific to that feature in the classifier neural network (the weights which link the value of the feature to each of the hidden units). We show experimentally on a population stratification task of interest to medical studies that the proposed approach can significantly reduce both the number of parameters and the error rate of the classifier.
[ { "version": "v1", "created": "Mon, 28 Nov 2016 20:50:32 GMT" }, { "version": "v2", "created": "Fri, 6 Jan 2017 18:51:52 GMT" }, { "version": "v3", "created": "Thu, 16 Mar 2017 21:09:28 GMT" } ]
2017-03-21T00:00:00
[ [ "Romero", "Adriana", "" ], [ "Carrier", "Pierre Luc", "" ], [ "Erraqabi", "Akram", "" ], [ "Sylvain", "Tristan", "" ], [ "Auvolat", "Alex", "" ], [ "Dejoie", "Etienne", "" ], [ "Legault", "Marc-André", "" ], [ "Dubé", "Marie-Pierre", "" ], [ "Hussin", "Julie G.", "" ], [ "Bengio", "Yoshua", "" ] ]
TITLE: Diet Networks: Thin Parameters for Fat Genomics ABSTRACT: Learning tasks such as those involving genomic data often poses a serious challenge: the number of input features can be orders of magnitude larger than the number of training examples, making it difficult to avoid overfitting, even when using the known regularization techniques. We focus here on tasks in which the input is a description of the genetic variation specific to a patient, the single nucleotide polymorphisms (SNPs), yielding millions of ternary inputs. Improving the ability of deep learning to handle such datasets could have an important impact in precision medicine, where high-dimensional data regarding a particular patient is used to make predictions of interest. Even though the amount of data for such tasks is increasing, this mismatch between the number of examples and the number of inputs remains a concern. Naive implementations of classifier neural networks involve a huge number of free parameters in their first layer: each input feature is associated with as many parameters as there are hidden units. We propose a novel neural network parametrization which considerably reduces the number of free parameters. It is based on the idea that we can first learn or provide a distributed representation for each input feature (e.g. for each position in the genome where variations are observed), and then learn (with another neural network called the parameter prediction network) how to map a feature's distributed representation to the vector of parameters specific to that feature in the classifier neural network (the weights which link the value of the feature to each of the hidden units). We show experimentally on a population stratification task of interest to medical studies that the proposed approach can significantly reduce both the number of parameters and the error rate of the classifier.
no_new_dataset
0.951594
1701.00180
Hamid Hamraz
Hamid Hamraz, Marco A. Contreras, and Jun Zhang
A scalable approach for tree segmentation within small-footprint airborne LiDAR data
The replacement version is exactly the same and only the journal biblio information and the DOI of the published version was added
Computers and Geosciences 102 (pp. 139-147): Elsevier (2017)
10.1016/j.cageo.2017.02.017
null
cs.DC cs.CE
http://creativecommons.org/licenses/by/4.0/
This paper presents a distributed approach that scales up to segment tree crowns within a LiDAR point cloud representing an arbitrarily large forested area. The approach uses a single-processor tree segmentation algorithm as a building block in order to process the data delivered in the shape of tiles in parallel. The distributed processing is performed in a master-slave manner, in which the master maintains the global map of the tiles and coordinates the slaves that segment tree crowns within and across the boundaries of the tiles. A minimal bias was introduced to the number of detected trees because of trees lying across the tile boundaries, which was quantified and adjusted for. Theoretical and experimental analyses of the runtime of the approach revealed a near linear speedup. The estimated number of trees categorized by crown class and the associated error margins as well as the height distribution of the detected trees aligned well with field estimations, verifying that the distributed approach works correctly. The approach enables providing information of individual tree locations and point cloud segments for a forest-level area in a timely manner, which can be used to create detailed remotely sensed forest inventories. Although the approach was presented for tree segmentation within LiDAR point clouds, the idea can also be generalized to scale up processing other big spatial datasets. Highlights: - A scalable distributed approach for tree segmentation was developed and theoretically analyzed. - ~2 million trees in a 7440 ha forest was segmented in 2.5 hours using 192 cores. - 2% false positive trees were identified as a result of the distributed run. - The approach can be used to scale up processing other big spatial data
[ { "version": "v1", "created": "Sun, 1 Jan 2017 00:10:42 GMT" }, { "version": "v2", "created": "Sun, 19 Mar 2017 21:13:31 GMT" } ]
2017-03-21T00:00:00
[ [ "Hamraz", "Hamid", "" ], [ "Contreras", "Marco A.", "" ], [ "Zhang", "Jun", "" ] ]
TITLE: A scalable approach for tree segmentation within small-footprint airborne LiDAR data ABSTRACT: This paper presents a distributed approach that scales up to segment tree crowns within a LiDAR point cloud representing an arbitrarily large forested area. The approach uses a single-processor tree segmentation algorithm as a building block in order to process the data delivered in the shape of tiles in parallel. The distributed processing is performed in a master-slave manner, in which the master maintains the global map of the tiles and coordinates the slaves that segment tree crowns within and across the boundaries of the tiles. A minimal bias was introduced to the number of detected trees because of trees lying across the tile boundaries, which was quantified and adjusted for. Theoretical and experimental analyses of the runtime of the approach revealed a near linear speedup. The estimated number of trees categorized by crown class and the associated error margins as well as the height distribution of the detected trees aligned well with field estimations, verifying that the distributed approach works correctly. The approach enables providing information of individual tree locations and point cloud segments for a forest-level area in a timely manner, which can be used to create detailed remotely sensed forest inventories. Although the approach was presented for tree segmentation within LiDAR point clouds, the idea can also be generalized to scale up processing other big spatial datasets. Highlights: - A scalable distributed approach for tree segmentation was developed and theoretically analyzed. - ~2 million trees in a 7440 ha forest was segmented in 2.5 hours using 192 cores. - 2% false positive trees were identified as a result of the distributed run. - The approach can be used to scale up processing other big spatial data
no_new_dataset
0.954563
1701.05524
Xingchao Peng
Xingchao Peng, Kate Saenko
Synthetic to Real Adaptation with Generative Correlation Alignment Networks
13 pages, 8 figures
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Synthetic images rendered from 3D CAD models are useful for augmenting training data for object recognition algorithms. However, the generated images are non-photorealistic and do not match real image statistics. This leads to a large domain discrepancy, causing models trained on synthetic data to perform poorly on real domains. Recent work has shown the great potential of deep convolutional neural networks to generate realistic images, but has not utilized generative models to address synthetic-to-real domain adaptation. In this work, we propose a Deep Generative Correlation Alignment Network (DGCAN) to synthesize images using a novel domain adaption algorithm. DGCAN leverages a shape preserving loss and a low level statistic matching loss to minimize the domain discrepancy between synthetic and real images in deep feature space. Experimentally, we show training off-the-shelf classifiers on the newly generated data can significantly boost performance when testing on the real image domains (PASCAL VOC 2007 benchmark and Office dataset), improving upon several existing methods.
[ { "version": "v1", "created": "Thu, 19 Jan 2017 17:42:00 GMT" }, { "version": "v2", "created": "Thu, 9 Mar 2017 20:41:32 GMT" }, { "version": "v3", "created": "Sat, 18 Mar 2017 12:56:45 GMT" } ]
2017-03-21T00:00:00
[ [ "Peng", "Xingchao", "" ], [ "Saenko", "Kate", "" ] ]
TITLE: Synthetic to Real Adaptation with Generative Correlation Alignment Networks ABSTRACT: Synthetic images rendered from 3D CAD models are useful for augmenting training data for object recognition algorithms. However, the generated images are non-photorealistic and do not match real image statistics. This leads to a large domain discrepancy, causing models trained on synthetic data to perform poorly on real domains. Recent work has shown the great potential of deep convolutional neural networks to generate realistic images, but has not utilized generative models to address synthetic-to-real domain adaptation. In this work, we propose a Deep Generative Correlation Alignment Network (DGCAN) to synthesize images using a novel domain adaption algorithm. DGCAN leverages a shape preserving loss and a low level statistic matching loss to minimize the domain discrepancy between synthetic and real images in deep feature space. Experimentally, we show training off-the-shelf classifiers on the newly generated data can significantly boost performance when testing on the real image domains (PASCAL VOC 2007 benchmark and Office dataset), improving upon several existing methods.
no_new_dataset
0.952175
1703.04566
Mohammad Azzeh
Mohammad Azzeh
Model tree based adaption strategy for software effort estimation by analogy
null
null
null
null
cs.SE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Background: Adaptation technique is a crucial task for analogy based estimation. Current adaptation techniques often use linear size or linear similarity adjustment mechanisms which are often not suitable for datasets that have complex structure with many categorical attributes. Furthermore, the use of nonlinear adaptation technique such as neural network and genetic algorithms needs many user interactions and parameters optimization for configuring them (such as network model, number of neurons, activation functions, training functions, mutation, selection, crossover, ... etc.). Aims: In response to the abovementioned challenges, the present paper proposes a new adaptation strategy using Model Tree based attribute distance to adjust estimation by analogy and derive new estimates. Using Model Tree has an advantage to deal with categorical attributes, minimize user interaction and improve efficiency of model learning through classification. Method: Seven well known datasets have been used with 3-Fold cross validation to empirically validate the proposed approach. The proposed method has been investigated using various K analogies from 1 to 3. Results: Experimental results showed that the proposed approach produced better results when compared with those obtained by using estimation by analogy based linear size adaptation, linear similarity adaptation, 'regression towards the mean' and null adaptation. Conclusions: Model Tree could form a useful extension for estimation by analogy especially for complex data sets with large number of categorical attributes.
[ { "version": "v1", "created": "Sat, 11 Mar 2017 20:22:34 GMT" } ]
2017-03-21T00:00:00
[ [ "Azzeh", "Mohammad", "" ] ]
TITLE: Model tree based adaption strategy for software effort estimation by analogy ABSTRACT: Background: Adaptation technique is a crucial task for analogy based estimation. Current adaptation techniques often use linear size or linear similarity adjustment mechanisms which are often not suitable for datasets that have complex structure with many categorical attributes. Furthermore, the use of nonlinear adaptation technique such as neural network and genetic algorithms needs many user interactions and parameters optimization for configuring them (such as network model, number of neurons, activation functions, training functions, mutation, selection, crossover, ... etc.). Aims: In response to the abovementioned challenges, the present paper proposes a new adaptation strategy using Model Tree based attribute distance to adjust estimation by analogy and derive new estimates. Using Model Tree has an advantage to deal with categorical attributes, minimize user interaction and improve efficiency of model learning through classification. Method: Seven well known datasets have been used with 3-Fold cross validation to empirically validate the proposed approach. The proposed method has been investigated using various K analogies from 1 to 3. Results: Experimental results showed that the proposed approach produced better results when compared with those obtained by using estimation by analogy based linear size adaptation, linear similarity adaptation, 'regression towards the mean' and null adaptation. Conclusions: Model Tree could form a useful extension for estimation by analogy especially for complex data sets with large number of categorical attributes.
no_new_dataset
0.952442
1703.04575
Mohammad Azzeh
Mohammad Azzeh
Dataset Quality Assessment: An extension for analogy based effort estimation
null
null
null
null
cs.SE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Estimation by Analogy (EBA) is an increasingly active research method in the area of software engineering. The fundamental assumption of this method is that the similar projects in terms of attribute values will also be similar in terms of effort values. It is well recognized that the quality of software datasets has a considerable impact on the reliability and accuracy of such method. Therefore, if the software dataset does not satisfy the aforementioned assumption then it is not rather useful for EBA method. This paper presents a new method based on Kendall's row-wise rank correlation that enables data quality evaluation and providing a data preprocessing stage for EBA. The proposed method provides sound statistical basis and justification for the process of data quality evaluation. Unlike Analogy-X, our method has the ability to deal with categorical attributes individually without the need for partitioning the dataset. Experimental results showed that the proposed method could form a useful extension for EBA as it enables: dataset quality evaluation, attribute selection and identifying abnormal observations.
[ { "version": "v1", "created": "Sat, 11 Mar 2017 20:36:17 GMT" } ]
2017-03-21T00:00:00
[ [ "Azzeh", "Mohammad", "" ] ]
TITLE: Dataset Quality Assessment: An extension for analogy based effort estimation ABSTRACT: Estimation by Analogy (EBA) is an increasingly active research method in the area of software engineering. The fundamental assumption of this method is that the similar projects in terms of attribute values will also be similar in terms of effort values. It is well recognized that the quality of software datasets has a considerable impact on the reliability and accuracy of such method. Therefore, if the software dataset does not satisfy the aforementioned assumption then it is not rather useful for EBA method. This paper presents a new method based on Kendall's row-wise rank correlation that enables data quality evaluation and providing a data preprocessing stage for EBA. The proposed method provides sound statistical basis and justification for the process of data quality evaluation. Unlike Analogy-X, our method has the ability to deal with categorical attributes individually without the need for partitioning the dataset. Experimental results showed that the proposed method could form a useful extension for EBA as it enables: dataset quality evaluation, attribute selection and identifying abnormal observations.
no_new_dataset
0.945298
1703.05002
Donghui Wang
Yanan Li, Donghui Wang, Huanhang Hu, Yuetan Lin, Yueting Zhuang
Zero-Shot Recognition using Dual Visual-Semantic Mapping Paths
Accepted as a full paper in IEEE Computer Vision and Pattern Recognition (CVPR) 2017
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Zero-shot recognition aims to accurately recognize objects of unseen classes by using a shared visual-semantic mapping between the image feature space and the semantic embedding space. This mapping is learned on training data of seen classes and is expected to have transfer ability to unseen classes. In this paper, we tackle this problem by exploiting the intrinsic relationship between the semantic space manifold and the transfer ability of visual-semantic mapping. We formalize their connection and cast zero-shot recognition as a joint optimization problem. Motivated by this, we propose a novel framework for zero-shot recognition, which contains dual visual-semantic mapping paths. Our analysis shows this framework can not only apply prior semantic knowledge to infer underlying semantic manifold in the image feature space, but also generate optimized semantic embedding space, which can enhance the transfer ability of the visual-semantic mapping to unseen classes. The proposed method is evaluated for zero-shot recognition on four benchmark datasets, achieving outstanding results.
[ { "version": "v1", "created": "Wed, 15 Mar 2017 08:28:58 GMT" }, { "version": "v2", "created": "Mon, 20 Mar 2017 01:46:27 GMT" } ]
2017-03-21T00:00:00
[ [ "Li", "Yanan", "" ], [ "Wang", "Donghui", "" ], [ "Hu", "Huanhang", "" ], [ "Lin", "Yuetan", "" ], [ "Zhuang", "Yueting", "" ] ]
TITLE: Zero-Shot Recognition using Dual Visual-Semantic Mapping Paths ABSTRACT: Zero-shot recognition aims to accurately recognize objects of unseen classes by using a shared visual-semantic mapping between the image feature space and the semantic embedding space. This mapping is learned on training data of seen classes and is expected to have transfer ability to unseen classes. In this paper, we tackle this problem by exploiting the intrinsic relationship between the semantic space manifold and the transfer ability of visual-semantic mapping. We formalize their connection and cast zero-shot recognition as a joint optimization problem. Motivated by this, we propose a novel framework for zero-shot recognition, which contains dual visual-semantic mapping paths. Our analysis shows this framework can not only apply prior semantic knowledge to infer underlying semantic manifold in the image feature space, but also generate optimized semantic embedding space, which can enhance the transfer ability of the visual-semantic mapping to unseen classes. The proposed method is evaluated for zero-shot recognition on four benchmark datasets, achieving outstanding results.
no_new_dataset
0.949529
1703.05908
Yao-Hung Tsai
Yao-Hung Hubert Tsai and Liang-Kang Huang and Ruslan Salakhutdinov
Learning Robust Visual-Semantic Embeddings
12 pages
null
null
null
cs.CV cs.CL cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Many of the existing methods for learning joint embedding of images and text use only supervised information from paired images and its textual attributes. Taking advantage of the recent success of unsupervised learning in deep neural networks, we propose an end-to-end learning framework that is able to extract more robust multi-modal representations across domains. The proposed method combines representation learning models (i.e., auto-encoders) together with cross-domain learning criteria (i.e., Maximum Mean Discrepancy loss) to learn joint embeddings for semantic and visual features. A novel technique of unsupervised-data adaptation inference is introduced to construct more comprehensive embeddings for both labeled and unlabeled data. We evaluate our method on Animals with Attributes and Caltech-UCSD Birds 200-2011 dataset with a wide range of applications, including zero and few-shot image recognition and retrieval, from inductive to transductive settings. Empirically, we show that our framework improves over the current state of the art on many of the considered tasks.
[ { "version": "v1", "created": "Fri, 17 Mar 2017 06:59:51 GMT" }, { "version": "v2", "created": "Mon, 20 Mar 2017 00:28:07 GMT" } ]
2017-03-21T00:00:00
[ [ "Tsai", "Yao-Hung Hubert", "" ], [ "Huang", "Liang-Kang", "" ], [ "Salakhutdinov", "Ruslan", "" ] ]
TITLE: Learning Robust Visual-Semantic Embeddings ABSTRACT: Many of the existing methods for learning joint embedding of images and text use only supervised information from paired images and its textual attributes. Taking advantage of the recent success of unsupervised learning in deep neural networks, we propose an end-to-end learning framework that is able to extract more robust multi-modal representations across domains. The proposed method combines representation learning models (i.e., auto-encoders) together with cross-domain learning criteria (i.e., Maximum Mean Discrepancy loss) to learn joint embeddings for semantic and visual features. A novel technique of unsupervised-data adaptation inference is introduced to construct more comprehensive embeddings for both labeled and unlabeled data. We evaluate our method on Animals with Attributes and Caltech-UCSD Birds 200-2011 dataset with a wide range of applications, including zero and few-shot image recognition and retrieval, from inductive to transductive settings. Empirically, we show that our framework improves over the current state of the art on many of the considered tasks.
no_new_dataset
0.940844
1703.06151
Sheng Zou
Sheng Zou, Hao Sun, Alina Zare
Hyperspectral Unmixing with Endmember Variability using Semi-supervised Partial Membership Latent Dirichlet Allocation
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A semi-supervised Partial Membership Latent Dirichlet Allocation approach is developed for hyperspectral unmixing and endmember estimation while accounting for spectral variability and spatial information. Partial Membership Latent Dirichlet Allocation is an effective approach for spectral unmixing while representing spectral variability and leveraging spatial information. In this work, we extend Partial Membership Latent Dirichlet Allocation to incorporate any available (imprecise) label information to help guide unmixing. Experimental results on two hyperspectral datasets show that the proposed semi-supervised PM-LDA can yield improved hyperspectral unmixing and endmember estimation results.
[ { "version": "v1", "created": "Fri, 17 Mar 2017 18:13:59 GMT" } ]
2017-03-21T00:00:00
[ [ "Zou", "Sheng", "" ], [ "Sun", "Hao", "" ], [ "Zare", "Alina", "" ] ]
TITLE: Hyperspectral Unmixing with Endmember Variability using Semi-supervised Partial Membership Latent Dirichlet Allocation ABSTRACT: A semi-supervised Partial Membership Latent Dirichlet Allocation approach is developed for hyperspectral unmixing and endmember estimation while accounting for spectral variability and spatial information. Partial Membership Latent Dirichlet Allocation is an effective approach for spectral unmixing while representing spectral variability and leveraging spatial information. In this work, we extend Partial Membership Latent Dirichlet Allocation to incorporate any available (imprecise) label information to help guide unmixing. Experimental results on two hyperspectral datasets show that the proposed semi-supervised PM-LDA can yield improved hyperspectral unmixing and endmember estimation results.
no_new_dataset
0.949435
1703.06300
Lech Madeyski
Jaros{\l}aw Hryszko and Lech Madeyski and Marta D\k{a}browska and Piotr Konopka
Defect prediction with bad smells in code
Chapter 10 in Software Engineering: Improving Practice through Research (B. Hnatkowska and M. \'Smia{\l}ek, eds.), pp. 163-176, 2016
null
null
null
cs.SE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Background: Defect prediction in software can be highly beneficial for development projects, when prediction is highly effective and defect-prone areas are predicted correctly. One of the key elements to gain effective software defect prediction is proper selection of metrics used for dataset preparation. Objective: The purpose of this research is to verify, whether code smells metrics, collected using Microsoft CodeAnalysis tool, added to basic metric set, can improve defect prediction in industrial software development project. Results: We verified, if dataset extension by the code smells sourced metrics, change the effectiveness of the defect prediction by comparing prediction results for datasets with and without code smells-oriented metrics. In a result, we observed only small improvement of effectiveness of defect prediction when dataset extended with bad smells metrics was used: average accuracy value increased by 0.0091 and stayed within the margin of error. However, when only use of code smells based metrics were used for prediction (without basic set of metrics), such process resulted with surprisingly high accuracy (0.8249) and F-measure (0.8286) results. We also elaborated data anomalies and problems we observed when two different metric sources were used to prepare one, consistent set of data. Conclusion: Extending the dataset by the code smells sourced metric does not significantly improve the prediction effectiveness. Achieved result did not compensate effort needed to collect additional metrics. However, we observed that defect prediction based on the code smells only is still highly effective and can be used especially where other metrics hardly be used.
[ { "version": "v1", "created": "Sat, 18 Mar 2017 13:55:50 GMT" } ]
2017-03-21T00:00:00
[ [ "Hryszko", "Jarosław", "" ], [ "Madeyski", "Lech", "" ], [ "Dąbrowska", "Marta", "" ], [ "Konopka", "Piotr", "" ] ]
TITLE: Defect prediction with bad smells in code ABSTRACT: Background: Defect prediction in software can be highly beneficial for development projects, when prediction is highly effective and defect-prone areas are predicted correctly. One of the key elements to gain effective software defect prediction is proper selection of metrics used for dataset preparation. Objective: The purpose of this research is to verify, whether code smells metrics, collected using Microsoft CodeAnalysis tool, added to basic metric set, can improve defect prediction in industrial software development project. Results: We verified, if dataset extension by the code smells sourced metrics, change the effectiveness of the defect prediction by comparing prediction results for datasets with and without code smells-oriented metrics. In a result, we observed only small improvement of effectiveness of defect prediction when dataset extended with bad smells metrics was used: average accuracy value increased by 0.0091 and stayed within the margin of error. However, when only use of code smells based metrics were used for prediction (without basic set of metrics), such process resulted with surprisingly high accuracy (0.8249) and F-measure (0.8286) results. We also elaborated data anomalies and problems we observed when two different metric sources were used to prepare one, consistent set of data. Conclusion: Extending the dataset by the code smells sourced metric does not significantly improve the prediction effectiveness. Achieved result did not compensate effort needed to collect additional metrics. However, we observed that defect prediction based on the code smells only is still highly effective and can be used especially where other metrics hardly be used.
no_new_dataset
0.952131
1703.06361
Lewis Mitchell
James P. Bagrow, Christopher M. Danforth, Lewis Mitchell
Which friends are more popular than you? Contact strength and the friendship paradox in social networks
null
null
null
null
cs.SI cs.CY physics.soc-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The friendship paradox states that in a social network, egos tend to have lower degree than their alters, or, "your friends have more friends than you do". Most research has focused on the friendship paradox and its implications for information transmission, but treating the network as static and unweighted. Yet, people can dedicate only a finite fraction of their attention budget to each social interaction: a high-degree individual may have less time to dedicate to individual social links, forcing them to modulate the quantities of contact made to their different social ties. Here we study the friendship paradox in the context of differing contact volumes between egos and alters, finding a connection between contact volume and the strength of the friendship paradox. The most frequently contacted alters exhibit a less pronounced friendship paradox compared with the ego, whereas less-frequently contacted alters are more likely to be high degree and give rise to the paradox. We argue therefore for a more nuanced version of the friendship paradox: "your closest friends have slightly more friends than you do", and in certain networks even: "your best friend has no more friends than you do". We demonstrate that this relationship is robust, holding in both a social media and a mobile phone dataset. These results have implications for information transfer and influence in social networks, which we explore using a simple dynamical model.
[ { "version": "v1", "created": "Sat, 18 Mar 2017 22:50:02 GMT" } ]
2017-03-21T00:00:00
[ [ "Bagrow", "James P.", "" ], [ "Danforth", "Christopher M.", "" ], [ "Mitchell", "Lewis", "" ] ]
TITLE: Which friends are more popular than you? Contact strength and the friendship paradox in social networks ABSTRACT: The friendship paradox states that in a social network, egos tend to have lower degree than their alters, or, "your friends have more friends than you do". Most research has focused on the friendship paradox and its implications for information transmission, but treating the network as static and unweighted. Yet, people can dedicate only a finite fraction of their attention budget to each social interaction: a high-degree individual may have less time to dedicate to individual social links, forcing them to modulate the quantities of contact made to their different social ties. Here we study the friendship paradox in the context of differing contact volumes between egos and alters, finding a connection between contact volume and the strength of the friendship paradox. The most frequently contacted alters exhibit a less pronounced friendship paradox compared with the ego, whereas less-frequently contacted alters are more likely to be high degree and give rise to the paradox. We argue therefore for a more nuanced version of the friendship paradox: "your closest friends have slightly more friends than you do", and in certain networks even: "your best friend has no more friends than you do". We demonstrate that this relationship is robust, holding in both a social media and a mobile phone dataset. These results have implications for information transfer and influence in social networks, which we explore using a simple dynamical model.
no_new_dataset
0.946794
1703.06380
Shichao Yang
Shichao Yang, Sebastian Scherer
Direct Monocular Odometry Using Points and Lines
ICRA 2017
null
null
null
cs.CV cs.RO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Most visual odometry algorithm for a monocular camera focuses on points, either by feature matching, or direct alignment of pixel intensity, while ignoring a common but important geometry entity: edges. In this paper, we propose an odometry algorithm that combines points and edges to benefit from the advantages of both direct and feature based methods. It works better in texture-less environments and is also more robust to lighting changes and fast motion by increasing the convergence basin. We maintain a depth map for the keyframe then in the tracking part, the camera pose is recovered by minimizing both the photometric error and geometric error to the matched edge in a probabilistic framework. In the mapping part, edge is used to speed up and increase stereo matching accuracy. On various public datasets, our algorithm achieves better or comparable performance than state-of-the-art monocular odometry methods. In some challenging texture-less environments, our algorithm reduces the state estimation error over 50%.
[ { "version": "v1", "created": "Sun, 19 Mar 2017 01:59:53 GMT" } ]
2017-03-21T00:00:00
[ [ "Yang", "Shichao", "" ], [ "Scherer", "Sebastian", "" ] ]
TITLE: Direct Monocular Odometry Using Points and Lines ABSTRACT: Most visual odometry algorithm for a monocular camera focuses on points, either by feature matching, or direct alignment of pixel intensity, while ignoring a common but important geometry entity: edges. In this paper, we propose an odometry algorithm that combines points and edges to benefit from the advantages of both direct and feature based methods. It works better in texture-less environments and is also more robust to lighting changes and fast motion by increasing the convergence basin. We maintain a depth map for the keyframe then in the tracking part, the camera pose is recovered by minimizing both the photometric error and geometric error to the matched edge in a probabilistic framework. In the mapping part, edge is used to speed up and increase stereo matching accuracy. On various public datasets, our algorithm achieves better or comparable performance than state-of-the-art monocular odometry methods. In some challenging texture-less environments, our algorithm reduces the state estimation error over 50%.
no_new_dataset
0.955402
1703.06541
Shervin Malmasi Ph.D.
Shervin Malmasi and Mark Dras
Native Language Identification using Stacked Generalization
null
null
null
null
cs.CL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Ensemble methods using multiple classifiers have proven to be the most successful approach for the task of Native Language Identification (NLI), achieving the current state of the art. However, a systematic examination of ensemble methods for NLI has yet to be conducted. Additionally, deeper ensemble architectures such as classifier stacking have not been closely evaluated. We present a set of experiments using three ensemble-based models, testing each with multiple configurations and algorithms. This includes a rigorous application of meta-classification models for NLI, achieving state-of-the-art results on three datasets from different languages. We also present the first use of statistical significance testing for comparing NLI systems, showing that our results are significantly better than the previous state of the art. We make available a collection of test set predictions to facilitate future statistical tests.
[ { "version": "v1", "created": "Sun, 19 Mar 2017 23:42:28 GMT" } ]
2017-03-21T00:00:00
[ [ "Malmasi", "Shervin", "" ], [ "Dras", "Mark", "" ] ]
TITLE: Native Language Identification using Stacked Generalization ABSTRACT: Ensemble methods using multiple classifiers have proven to be the most successful approach for the task of Native Language Identification (NLI), achieving the current state of the art. However, a systematic examination of ensemble methods for NLI has yet to be conducted. Additionally, deeper ensemble architectures such as classifier stacking have not been closely evaluated. We present a set of experiments using three ensemble-based models, testing each with multiple configurations and algorithms. This includes a rigorous application of meta-classification models for NLI, achieving state-of-the-art results on three datasets from different languages. We also present the first use of statistical significance testing for comparing NLI systems, showing that our results are significantly better than the previous state of the art. We make available a collection of test set predictions to facilitate future statistical tests.
no_new_dataset
0.903465
1703.06618
Yuting Hu
Yuting Hu, Liang Zheng, Yi Yang, and Yongfeng Huang
Twitter100k: A Real-world Dataset for Weakly Supervised Cross-Media Retrieval
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper contributes a new large-scale dataset for weakly supervised cross-media retrieval, named Twitter100k. Current datasets, such as Wikipedia, NUS Wide and Flickr30k, have two major limitations. First, these datasets are lacking in content diversity, i.e., only some pre-defined classes are covered. Second, texts in these datasets are written in well-organized language, leading to inconsistency with realistic applications. To overcome these drawbacks, the proposed Twitter100k dataset is characterized by two aspects: 1) it has 100,000 image-text pairs randomly crawled from Twitter and thus has no constraint in the image categories; 2) text in Twitter100k is written in informal language by the users. Since strongly supervised methods leverage the class labels that may be missing in practice, this paper focuses on weakly supervised learning for cross-media retrieval, in which only text-image pairs are exploited during training. We extensively benchmark the performance of four subspace learning methods and three variants of the Correspondence AutoEncoder, along with various text features on Wikipedia, Flickr30k and Twitter100k. Novel insights are provided. As a minor contribution, inspired by the characteristic of Twitter100k, we propose an OCR-based cross-media retrieval method. In experiment, we show that the proposed OCR-based method improves the baseline performance.
[ { "version": "v1", "created": "Mon, 20 Mar 2017 06:56:33 GMT" } ]
2017-03-21T00:00:00
[ [ "Hu", "Yuting", "" ], [ "Zheng", "Liang", "" ], [ "Yang", "Yi", "" ], [ "Huang", "Yongfeng", "" ] ]
TITLE: Twitter100k: A Real-world Dataset for Weakly Supervised Cross-Media Retrieval ABSTRACT: This paper contributes a new large-scale dataset for weakly supervised cross-media retrieval, named Twitter100k. Current datasets, such as Wikipedia, NUS Wide and Flickr30k, have two major limitations. First, these datasets are lacking in content diversity, i.e., only some pre-defined classes are covered. Second, texts in these datasets are written in well-organized language, leading to inconsistency with realistic applications. To overcome these drawbacks, the proposed Twitter100k dataset is characterized by two aspects: 1) it has 100,000 image-text pairs randomly crawled from Twitter and thus has no constraint in the image categories; 2) text in Twitter100k is written in informal language by the users. Since strongly supervised methods leverage the class labels that may be missing in practice, this paper focuses on weakly supervised learning for cross-media retrieval, in which only text-image pairs are exploited during training. We extensively benchmark the performance of four subspace learning methods and three variants of the Correspondence AutoEncoder, along with various text features on Wikipedia, Flickr30k and Twitter100k. Novel insights are provided. As a minor contribution, inspired by the characteristic of Twitter100k, we propose an OCR-based cross-media retrieval method. In experiment, we show that the proposed OCR-based method improves the baseline performance.
new_dataset
0.969957
1610.02517
Ali Bou Nassif
Mohammad Azzeh, Ali Bou Nassif
A Hybrid Model for Estimating Software Project Effort from Use Case Points
null
null
10.1016/j.asoc.2016.05.008
null
cs.SE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Early software effort estimation is a hallmark of successful software project management. Building a reliable effort estimation model usually requires historical data. Unfortunately, since the information available at early stages of software development is scarce, it is recommended to use software size metrics as key cost factor of effort estimation. Use Case Points (UCP) is a prominent size measure designed mainly for object-oriented projects. Nevertheless, there are no established models that can translate UCP into its corresponding effort, therefore, most models use productivity as a second cost driver. The productivity in those models is usually guessed by experts and does not depend on historical data, which makes it subject to uncertainty. Thus, these models were not well examined using a large number of historical data. In this paper, we designed a hybrid model that consists of classification and prediction stages using a support vector machine and radial basis neural networks. The proposed model was constructed over a large number of observations collected from industrial and student projects. The proposed model was compared against previous UCP prediction models. The validation and empirical results demonstrated that the proposed model significantly surpasses these models on all datasets. The main conclusion is that the environmental factors of UCP can be used to classify and estimate productivity.
[ { "version": "v1", "created": "Sat, 8 Oct 2016 12:18:18 GMT" } ]
2017-03-20T00:00:00
[ [ "Azzeh", "Mohammad", "" ], [ "Nassif", "Ali Bou", "" ] ]
TITLE: A Hybrid Model for Estimating Software Project Effort from Use Case Points ABSTRACT: Early software effort estimation is a hallmark of successful software project management. Building a reliable effort estimation model usually requires historical data. Unfortunately, since the information available at early stages of software development is scarce, it is recommended to use software size metrics as key cost factor of effort estimation. Use Case Points (UCP) is a prominent size measure designed mainly for object-oriented projects. Nevertheless, there are no established models that can translate UCP into its corresponding effort, therefore, most models use productivity as a second cost driver. The productivity in those models is usually guessed by experts and does not depend on historical data, which makes it subject to uncertainty. Thus, these models were not well examined using a large number of historical data. In this paper, we designed a hybrid model that consists of classification and prediction stages using a support vector machine and radial basis neural networks. The proposed model was constructed over a large number of observations collected from industrial and student projects. The proposed model was compared against previous UCP prediction models. The validation and empirical results demonstrated that the proposed model significantly surpasses these models on all datasets. The main conclusion is that the environmental factors of UCP can be used to classify and estimate productivity.
no_new_dataset
0.948537
1611.06947
Rongrong Tao
Rongrong Tao, Baojian Zhou, Feng Chen, Naifeng Liu, David Mares, Patrick Butler, Naren Ramakrishnan
Can Self-Censorship in News Media be Detected Algorithmically? A Case Study in Latin America
null
null
null
null
cs.SI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Censorship in social media has been well studied and provides insight into how governments stifle freedom of expression online. Comparatively less (or no) attention has been paid to detecting (self) censorship in traditional media (e.g., news) using social media as a bellweather. We present a novel unsupervised approach that views social media as a sensor to detect censorship in news media wherein statistically significant differences between information published in the news media and the correlated information published in social media are automatically identified as candidate censored events. We develop a hypothesis testing framework to identify and evaluate censored clusters of keywords, and a new near-linear-time algorithm (called GraphDPD) to identify the highest scoring clusters as indicators of censorship. We outline extensive experiments on semi-synthetic data as well as real datasets (with Twitter and local news media) from Mexico and Venezuela, highlighting the capability to accurately detect real-world self censorship events.
[ { "version": "v1", "created": "Mon, 21 Nov 2016 18:57:02 GMT" }, { "version": "v2", "created": "Fri, 17 Mar 2017 04:28:53 GMT" } ]
2017-03-20T00:00:00
[ [ "Tao", "Rongrong", "" ], [ "Zhou", "Baojian", "" ], [ "Chen", "Feng", "" ], [ "Liu", "Naifeng", "" ], [ "Mares", "David", "" ], [ "Butler", "Patrick", "" ], [ "Ramakrishnan", "Naren", "" ] ]
TITLE: Can Self-Censorship in News Media be Detected Algorithmically? A Case Study in Latin America ABSTRACT: Censorship in social media has been well studied and provides insight into how governments stifle freedom of expression online. Comparatively less (or no) attention has been paid to detecting (self) censorship in traditional media (e.g., news) using social media as a bellweather. We present a novel unsupervised approach that views social media as a sensor to detect censorship in news media wherein statistically significant differences between information published in the news media and the correlated information published in social media are automatically identified as candidate censored events. We develop a hypothesis testing framework to identify and evaluate censored clusters of keywords, and a new near-linear-time algorithm (called GraphDPD) to identify the highest scoring clusters as indicators of censorship. We outline extensive experiments on semi-synthetic data as well as real datasets (with Twitter and local news media) from Mexico and Venezuela, highlighting the capability to accurately detect real-world self censorship events.
no_new_dataset
0.948394
1701.04224
Chunlin Tian
Chunlin Tian, Weijun Ji
Auxiliary Multimodal LSTM for Audio-visual Speech Recognition and Lipreading
8 pages, 4 figures
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Aduio-visual Speech Recognition (AVSR) which employs both the video and audio information to do Automatic Speech Recognition (ASR) is one of the application of multimodal leaning making ASR system more robust and accuracy. The traditional models usually treated AVSR as inference or projection but strict prior limits its ability. As the revival of deep learning, Deep Neural Networks (DNN) becomes an important toolkit in many traditional classification tasks including ASR, image classification, natural language processing. Some DNN models were used in AVSR like Multimodal Deep Autoencoders (MDAEs), Multimodal Deep Belief Network (MDBN) and Multimodal Deep Boltzmann Machine (MDBM) that actually work better than traditional methods. However, such DNN models have several shortcomings: (1) They don't balance the modal fusion and temporal fusion, or even haven't temporal fusion; (2)The architecture of these models isn't end-to-end, the training and testing getting cumbersome. We propose a DNN model, Auxiliary Multimodal LSTM (am-LSTM), to overcome such weakness. The am-LSTM could be trained and tested once, moreover easy to train and preventing overfitting automatically. The extensibility and flexibility are also take into consideration. The experiments show that am-LSTM is much better than traditional methods and other DNN models in three datasets.
[ { "version": "v1", "created": "Mon, 16 Jan 2017 10:08:22 GMT" }, { "version": "v2", "created": "Fri, 17 Mar 2017 14:57:06 GMT" } ]
2017-03-20T00:00:00
[ [ "Tian", "Chunlin", "" ], [ "Ji", "Weijun", "" ] ]
TITLE: Auxiliary Multimodal LSTM for Audio-visual Speech Recognition and Lipreading ABSTRACT: The Aduio-visual Speech Recognition (AVSR) which employs both the video and audio information to do Automatic Speech Recognition (ASR) is one of the application of multimodal leaning making ASR system more robust and accuracy. The traditional models usually treated AVSR as inference or projection but strict prior limits its ability. As the revival of deep learning, Deep Neural Networks (DNN) becomes an important toolkit in many traditional classification tasks including ASR, image classification, natural language processing. Some DNN models were used in AVSR like Multimodal Deep Autoencoders (MDAEs), Multimodal Deep Belief Network (MDBN) and Multimodal Deep Boltzmann Machine (MDBM) that actually work better than traditional methods. However, such DNN models have several shortcomings: (1) They don't balance the modal fusion and temporal fusion, or even haven't temporal fusion; (2)The architecture of these models isn't end-to-end, the training and testing getting cumbersome. We propose a DNN model, Auxiliary Multimodal LSTM (am-LSTM), to overcome such weakness. The am-LSTM could be trained and tested once, moreover easy to train and preventing overfitting automatically. The extensibility and flexibility are also take into consideration. The experiments show that am-LSTM is much better than traditional methods and other DNN models in three datasets.
no_new_dataset
0.942029
1703.02769
Kiran Garimella
Kiran Garimella, Ingmar Weber
A Long-Term Analysis of Polarization on Twitter
This is a preprint of a short paper accepted at ICWSM'17. Please cite that version instead
null
null
null
cs.SI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Social media has played an important role in shaping political discourse over the last decade. At the same time, it is often perceived to have increased political polarization, thanks to the scale of discussions and their public nature. In this paper, we try to answer the question of whether political polarization in the US on Twitter has increased over the last eight years. We analyze a large longitudinal Twitter dataset of 679,000 users and look at signs of polarization in their (i) network - how people follow political and media accounts, (ii) tweeting behavior - whether they retweet content from both sides, and (iii) content - how partisan the hashtags they use are. Our analysis shows that online polarization has indeed increased over the past eight years and that, depending on the measure, the relative change is 10%-20%. Our study is one of very few with such a long-term perspective, encompassing two US presidential elections and two mid-term elections, providing a rare longitudinal analysis.
[ { "version": "v1", "created": "Wed, 8 Mar 2017 10:12:45 GMT" }, { "version": "v2", "created": "Fri, 17 Mar 2017 06:15:59 GMT" } ]
2017-03-20T00:00:00
[ [ "Garimella", "Kiran", "" ], [ "Weber", "Ingmar", "" ] ]
TITLE: A Long-Term Analysis of Polarization on Twitter ABSTRACT: Social media has played an important role in shaping political discourse over the last decade. At the same time, it is often perceived to have increased political polarization, thanks to the scale of discussions and their public nature. In this paper, we try to answer the question of whether political polarization in the US on Twitter has increased over the last eight years. We analyze a large longitudinal Twitter dataset of 679,000 users and look at signs of polarization in their (i) network - how people follow political and media accounts, (ii) tweeting behavior - whether they retweet content from both sides, and (iii) content - how partisan the hashtags they use are. Our analysis shows that online polarization has indeed increased over the past eight years and that, depending on the measure, the relative change is 10%-20%. Our study is one of very few with such a long-term perspective, encompassing two US presidential elections and two mid-term elections, providing a rare longitudinal analysis.
no_new_dataset
0.911101
1703.04564
Mohammad Azzeh
Mohammad Azzeh, Ali Bou Nassif
Analogy-based effort estimation: a new method to discover set of analogies from dataset characteristics
null
null
null
null
cs.SE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Analogy-based effort estimation (ABE) is one of the efficient methods for software effort estimation because of its outstanding performance and capability of handling noisy datasets. Conventional ABE models usually use the same number of analogies for all projects in the datasets in order to make good estimates. The authors' claim is that using same number of analogies may produce overall best performance for the whole dataset but not necessarily best performance for each individual project. Therefore there is a need to better understand the dataset characteristics in order to discover the optimum set of analogies for each project rather than using a static k nearest projects. Method: We propose a new technique based on Bisecting k-medoids clustering algorithm to come up with the best set of analogies for each individual project before making the prediction. Results & Conclusions: With Bisecting k-medoids it is possible to better understand the dataset characteristic, and automatically find best set of analogies for each test project. Performance figures of the proposed estimation method are promising and better than those of other regular ABE models
[ { "version": "v1", "created": "Sat, 11 Mar 2017 20:27:08 GMT" } ]
2017-03-20T00:00:00
[ [ "Azzeh", "Mohammad", "" ], [ "Nassif", "Ali Bou", "" ] ]
TITLE: Analogy-based effort estimation: a new method to discover set of analogies from dataset characteristics ABSTRACT: Analogy-based effort estimation (ABE) is one of the efficient methods for software effort estimation because of its outstanding performance and capability of handling noisy datasets. Conventional ABE models usually use the same number of analogies for all projects in the datasets in order to make good estimates. The authors' claim is that using same number of analogies may produce overall best performance for the whole dataset but not necessarily best performance for each individual project. Therefore there is a need to better understand the dataset characteristics in order to discover the optimum set of analogies for each project rather than using a static k nearest projects. Method: We propose a new technique based on Bisecting k-medoids clustering algorithm to come up with the best set of analogies for each individual project before making the prediction. Results & Conclusions: With Bisecting k-medoids it is possible to better understand the dataset characteristic, and automatically find best set of analogies for each test project. Performance figures of the proposed estimation method are promising and better than those of other regular ABE models
no_new_dataset
0.950549
1703.04565
Mohammad Azzeh
Mohammad Azzeh, Ali Bou Nassif
Fuzzy Model Tree For Early Effort Estimation
null
null
null
null
cs.SE cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Use Case Points (UCP) is a well-known method to estimate the project size, based on Use Case diagram, at early phases of software development. Although the Use Case diagram is widely accepted as a de-facto model for analyzing object oriented software requirements over the world, UCP method did not take sufficient amount of attention because, as yet, there is no consensus on how to produce software effort from UCP. This paper aims to study the potential of using Fuzzy Model Tree to derive effort estimates based on UCP size measure using a dataset collected for that purpose. The proposed approach has been validated against Treeboost model, Multiple Linear Regression and classical effort estimation based on the UCP model. The obtained results are promising and show better performance than those obtained by classical UCP, Multiple Linear Regression and slightly better than those obtained by Tree boost model.
[ { "version": "v1", "created": "Sat, 11 Mar 2017 20:24:06 GMT" } ]
2017-03-20T00:00:00
[ [ "Azzeh", "Mohammad", "" ], [ "Nassif", "Ali Bou", "" ] ]
TITLE: Fuzzy Model Tree For Early Effort Estimation ABSTRACT: Use Case Points (UCP) is a well-known method to estimate the project size, based on Use Case diagram, at early phases of software development. Although the Use Case diagram is widely accepted as a de-facto model for analyzing object oriented software requirements over the world, UCP method did not take sufficient amount of attention because, as yet, there is no consensus on how to produce software effort from UCP. This paper aims to study the potential of using Fuzzy Model Tree to derive effort estimates based on UCP size measure using a dataset collected for that purpose. The proposed approach has been validated against Treeboost model, Multiple Linear Regression and classical effort estimation based on the UCP model. The obtained results are promising and show better performance than those obtained by classical UCP, Multiple Linear Regression and slightly better than those obtained by Tree boost model.
no_new_dataset
0.899387
1703.04567
Mohammad Azzeh
Mohammad Azzeh, Yousef Elsheikh
Learning best K analogies from data distribution for case-based software effort estimation
arXiv admin note: substantial text overlap with arXiv: 1703.04564
null
null
null
cs.SE cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Case-Based Reasoning (CBR) has been widely used to generate good software effort estimates. The predictive performance of CBR is a dataset dependent and subject to extremely large space of configuration possibilities. Regardless of the type of adaptation technique, deciding on the optimal number of similar cases to be used before applying CBR is a key challenge. In this paper we propose a new technique based on Bisecting k-medoids clustering algorithm to better understanding the structure of a dataset and discovering the the optimal cases for each individual project by excluding irrelevant cases. Results obtained showed that understanding of the data characteristic prior prediction stage can help in automatically finding the best number of cases for each test project. Performance figures of the proposed estimation method are better than those of other regular K-based CBR methods.
[ { "version": "v1", "created": "Sat, 11 Mar 2017 20:19:05 GMT" } ]
2017-03-20T00:00:00
[ [ "Azzeh", "Mohammad", "" ], [ "Elsheikh", "Yousef", "" ] ]
TITLE: Learning best K analogies from data distribution for case-based software effort estimation ABSTRACT: Case-Based Reasoning (CBR) has been widely used to generate good software effort estimates. The predictive performance of CBR is a dataset dependent and subject to extremely large space of configuration possibilities. Regardless of the type of adaptation technique, deciding on the optimal number of similar cases to be used before applying CBR is a key challenge. In this paper we propose a new technique based on Bisecting k-medoids clustering algorithm to better understanding the structure of a dataset and discovering the the optimal cases for each individual project by excluding irrelevant cases. Results obtained showed that understanding of the data characteristic prior prediction stage can help in automatically finding the best number of cases for each test project. Performance figures of the proposed estimation method are better than those of other regular K-based CBR methods.
no_new_dataset
0.951006
1703.04568
Mohammad Azzeh
Mohammad Azzeh, Ali Bou Nassif, Leandro L Minku
An empirical evaluation of ensemble adjustment methods for analogy-based effort estimation
null
null
10.1016/j.jss.2015.01.028
null
cs.SE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Objective: This paper investigates the potential of ensemble learning for variants of adjustment methods used in analogy-based effort estimation. The number k of analogies to be used is also investigated. Method We perform a large scale comparison study where many ensembles constructed from n out of 40 possible valid variants of adjustment methods are applied to eight datasets. The performance of each method was evaluated based on standardized accuracy and effect size. Results: The results have been subjected to statistical significance testing, and show reasonable significant improvements on the predictive performance where ensemble methods are applied. Conclusion: Our conclusions suggest that ensembles of adjustment methods can work well and achieve good performance, even though they are not always superior to single methods. We also recommend constructing ensembles from only linear adjustment methods, as they have shown better performance and were frequently ranked higher.
[ { "version": "v1", "created": "Sat, 11 Mar 2017 20:16:37 GMT" } ]
2017-03-20T00:00:00
[ [ "Azzeh", "Mohammad", "" ], [ "Nassif", "Ali Bou", "" ], [ "Minku", "Leandro L", "" ] ]
TITLE: An empirical evaluation of ensemble adjustment methods for analogy-based effort estimation ABSTRACT: Objective: This paper investigates the potential of ensemble learning for variants of adjustment methods used in analogy-based effort estimation. The number k of analogies to be used is also investigated. Method We perform a large scale comparison study where many ensembles constructed from n out of 40 possible valid variants of adjustment methods are applied to eight datasets. The performance of each method was evaluated based on standardized accuracy and effect size. Results: The results have been subjected to statistical significance testing, and show reasonable significant improvements on the predictive performance where ensemble methods are applied. Conclusion: Our conclusions suggest that ensembles of adjustment methods can work well and achieve good performance, even though they are not always superior to single methods. We also recommend constructing ensembles from only linear adjustment methods, as they have shown better performance and were frequently ranked higher.
no_new_dataset
0.950088
1703.05778
Ali Sharifara
Ali Sharifara, and Amir Ghaderi
Medical Image Watermarking using 2D-DWT with Enhanced security and capacity
null
null
null
null
cs.MM cs.CR
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Teleradiology enables medical images to be transferred over the computer networks for many purposes including clinical interpretation, diagnosis, archive, etc. In telemedicine, medical images can be manipulated while transferring. In addition, medical information security requirements are specified by the legislative rules, and concerned entities must adhere to them. In this research, we propose a new scheme based on 2-dimensional Discrete Wavelet Transform (2D DWT) to improve the robustness and authentication of medical images. In addition, the current research improves security and capacity of watermarking using encryption and compression in medical images. The evaluation is performed on the personal dataset, which contains 194 CTI and 68 MRI cases.
[ { "version": "v1", "created": "Thu, 16 Mar 2017 18:05:32 GMT" } ]
2017-03-20T00:00:00
[ [ "Sharifara", "Ali", "" ], [ "Ghaderi", "Amir", "" ] ]
TITLE: Medical Image Watermarking using 2D-DWT with Enhanced security and capacity ABSTRACT: Teleradiology enables medical images to be transferred over the computer networks for many purposes including clinical interpretation, diagnosis, archive, etc. In telemedicine, medical images can be manipulated while transferring. In addition, medical information security requirements are specified by the legislative rules, and concerned entities must adhere to them. In this research, we propose a new scheme based on 2-dimensional Discrete Wavelet Transform (2D DWT) to improve the robustness and authentication of medical images. In addition, the current research improves security and capacity of watermarking using encryption and compression in medical images. The evaluation is performed on the personal dataset, which contains 194 CTI and 68 MRI cases.
new_dataset
0.956391
1703.05819
Dmytro Karamshuk
Dmytro Karamshuk, Tetyana Lokot, Oleksandr Pryymak, Nishanth Sastry
Identifying Partisan Slant in News Articles and Twitter during Political Crises
International Conference on Social Informatics (SocInfo 2016)
null
10.1007/978-3-319-47880-7_16
null
cs.SI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we are interested in understanding the interrelationships between mainstream and social media in forming public opinion during mass crises, specifically in regards to how events are framed in the mainstream news and on social networks and to how the language used in those frames may allow to infer political slant and partisanship. We study the lingual choices for political agenda setting in mainstream and social media by analyzing a dataset of more than 40M tweets and more than 4M news articles from the mass protests in Ukraine during 2013-2014 - known as "Euromaidan" - and the post-Euromaidan conflict between Russian, pro-Russian and Ukrainian forces in eastern Ukraine and Crimea. We design a natural language processing algorithm to analyze at scale the linguistic markers which point to a particular political leaning in online media and show that political slant in news articles and Twitter posts can be inferred with a high level of accuracy. These findings allow us to better understand the dynamics of partisan opinion formation during mass crises and the interplay between main- stream and social media in such circumstances.
[ { "version": "v1", "created": "Thu, 16 Mar 2017 21:07:59 GMT" } ]
2017-03-20T00:00:00
[ [ "Karamshuk", "Dmytro", "" ], [ "Lokot", "Tetyana", "" ], [ "Pryymak", "Oleksandr", "" ], [ "Sastry", "Nishanth", "" ] ]
TITLE: Identifying Partisan Slant in News Articles and Twitter during Political Crises ABSTRACT: In this paper, we are interested in understanding the interrelationships between mainstream and social media in forming public opinion during mass crises, specifically in regards to how events are framed in the mainstream news and on social networks and to how the language used in those frames may allow to infer political slant and partisanship. We study the lingual choices for political agenda setting in mainstream and social media by analyzing a dataset of more than 40M tweets and more than 4M news articles from the mass protests in Ukraine during 2013-2014 - known as "Euromaidan" - and the post-Euromaidan conflict between Russian, pro-Russian and Ukrainian forces in eastern Ukraine and Crimea. We design a natural language processing algorithm to analyze at scale the linguistic markers which point to a particular political leaning in online media and show that political slant in news articles and Twitter posts can be inferred with a high level of accuracy. These findings allow us to better understand the dynamics of partisan opinion formation during mass crises and the interplay between main- stream and social media in such circumstances.
no_new_dataset
0.910067
1703.06003
Huy Phan
Huy Q. Phan, Hongbo Fu, and Antoni B. Chan
Color Orchestra: Ordering Color Palettes for Interpolation and Prediction
IEEE Transactions on Visualization and Computer Graphics
null
null
null
cs.CV cs.GR
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Color theme or color palette can deeply influence the quality and the feeling of a photograph or a graphical design. Although color palettes may come from different sources such as online crowd-sourcing, photographs and graphical designs, in this paper, we consider color palettes extracted from fine art collections, which we believe to be an abundant source of stylistic and unique color themes. We aim to capture color styles embedded in these collections by means of statistical models and to build practical applications upon these models. As artists often use their personal color themes in their paintings, making these palettes appear frequently in the dataset, we employed density estimation to capture the characteristics of palette data. Via density estimation, we carried out various predictions and interpolations on palettes, which led to promising applications such as photo-style exploration, real-time color suggestion, and enriched photo recolorization. It was, however, challenging to apply density estimation to palette data as palettes often come as unordered sets of colors, which make it difficult to use conventional metrics on them. To this end, we developed a divide-and-conquer sorting algorithm to rearrange the colors in the palettes in a coherent order, which allows meaningful interpolation between color palettes. To confirm the performance of our model, we also conducted quantitative experiments on datasets of digitized paintings collected from the Internet and received favorable results.
[ { "version": "v1", "created": "Fri, 17 Mar 2017 13:25:49 GMT" } ]
2017-03-20T00:00:00
[ [ "Phan", "Huy Q.", "" ], [ "Fu", "Hongbo", "" ], [ "Chan", "Antoni B.", "" ] ]
TITLE: Color Orchestra: Ordering Color Palettes for Interpolation and Prediction ABSTRACT: Color theme or color palette can deeply influence the quality and the feeling of a photograph or a graphical design. Although color palettes may come from different sources such as online crowd-sourcing, photographs and graphical designs, in this paper, we consider color palettes extracted from fine art collections, which we believe to be an abundant source of stylistic and unique color themes. We aim to capture color styles embedded in these collections by means of statistical models and to build practical applications upon these models. As artists often use their personal color themes in their paintings, making these palettes appear frequently in the dataset, we employed density estimation to capture the characteristics of palette data. Via density estimation, we carried out various predictions and interpolations on palettes, which led to promising applications such as photo-style exploration, real-time color suggestion, and enriched photo recolorization. It was, however, challenging to apply density estimation to palette data as palettes often come as unordered sets of colors, which make it difficult to use conventional metrics on them. To this end, we developed a divide-and-conquer sorting algorithm to rearrange the colors in the palettes in a coherent order, which allows meaningful interpolation between color palettes. To confirm the performance of our model, we also conducted quantitative experiments on datasets of digitized paintings collected from the Internet and received favorable results.
no_new_dataset
0.955858
1703.06063
Mansaf Alam Dr
Samiya Khan, Mansaf Alam
Outcome-Based Quality Assessment Framework for Higher Education
null
null
null
null
cs.CY
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This research paper proposes a quality framework for higher education that evaluates the performance of institutions on the basis of performance of outgoing students. Literature was surveyed to evaluate existing quality frameworks and develop a framework that provides insights on an unexplored dimension of quality. In order to implement and test the framework, cloud-based big data technology, BigQuery, was used with R to perform analytics. It was found that how the students fair after passing out of a course is the outcome of educational process. This aspect can also be used as a quality metric for performance evaluation and management of educational organizations. However, it has not been taken into account in existing research. The lack of an integrated data collection system and rich datasets for educational intelligence applications, are some of the limitations that plague this area of research. Educational organizations are responsible for the performance of their students even after they complete their course. The inclusion of this dimension to quality assessment shall allow evaluation of educational institutions on these grounds. Assurance of this quality dimension shall boost enrolments in postgraduate and research degrees. Moreover, educational institutions will be motivated to groom students for placements or higher studies.
[ { "version": "v1", "created": "Wed, 15 Mar 2017 09:59:23 GMT" } ]
2017-03-20T00:00:00
[ [ "Khan", "Samiya", "" ], [ "Alam", "Mansaf", "" ] ]
TITLE: Outcome-Based Quality Assessment Framework for Higher Education ABSTRACT: This research paper proposes a quality framework for higher education that evaluates the performance of institutions on the basis of performance of outgoing students. Literature was surveyed to evaluate existing quality frameworks and develop a framework that provides insights on an unexplored dimension of quality. In order to implement and test the framework, cloud-based big data technology, BigQuery, was used with R to perform analytics. It was found that how the students fair after passing out of a course is the outcome of educational process. This aspect can also be used as a quality metric for performance evaluation and management of educational organizations. However, it has not been taken into account in existing research. The lack of an integrated data collection system and rich datasets for educational intelligence applications, are some of the limitations that plague this area of research. Educational organizations are responsible for the performance of their students even after they complete their course. The inclusion of this dimension to quality assessment shall allow evaluation of educational institutions on these grounds. Assurance of this quality dimension shall boost enrolments in postgraduate and research degrees. Moreover, educational institutions will be motivated to groom students for placements or higher studies.
no_new_dataset
0.940572
1703.06108
Nemanja Spasojevic
Prantik Bhattacharyya, Nemanja Spasojevic
Global Entity Ranking Across Multiple Languages
2 Pages, 1 Figure, 2 Tables, WWW2017 Companion, WWW 2017 Companion
null
10.1145/3041021.3054213
null
cs.IR cs.CL cs.SI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present work on building a global long-tailed ranking of entities across multiple languages using Wikipedia and Freebase knowledge bases. We identify multiple features and build a model to rank entities using a ground-truth dataset of more than 10 thousand labels. The final system ranks 27 million entities with 75% precision and 48% F1 score. We provide performance evaluation and empirical evidence of the quality of ranking across languages, and open the final ranked lists for future research.
[ { "version": "v1", "created": "Fri, 17 Mar 2017 17:16:02 GMT" } ]
2017-03-20T00:00:00
[ [ "Bhattacharyya", "Prantik", "" ], [ "Spasojevic", "Nemanja", "" ] ]
TITLE: Global Entity Ranking Across Multiple Languages ABSTRACT: We present work on building a global long-tailed ranking of entities across multiple languages using Wikipedia and Freebase knowledge bases. We identify multiple features and build a model to rank entities using a ground-truth dataset of more than 10 thousand labels. The final system ranks 27 million entities with 75% precision and 48% F1 score. We provide performance evaluation and empirical evidence of the quality of ranking across languages, and open the final ranked lists for future research.
no_new_dataset
0.941547
1510.02969
Pooya Khorrami
Pooya Khorrami, Tom Le Paine, Thomas S. Huang
Do Deep Neural Networks Learn Facial Action Units When Doing Expression Recognition?
Accepted at ICCV 2015 CV4AC Workshop. Corrected numbers in Tables 2 and 3
null
null
null
cs.CV cs.LG cs.NE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Despite being the appearance-based classifier of choice in recent years, relatively few works have examined how much convolutional neural networks (CNNs) can improve performance on accepted expression recognition benchmarks and, more importantly, examine what it is they actually learn. In this work, not only do we show that CNNs can achieve strong performance, but we also introduce an approach to decipher which portions of the face influence the CNN's predictions. First, we train a zero-bias CNN on facial expression data and achieve, to our knowledge, state-of-the-art performance on two expression recognition benchmarks: the extended Cohn-Kanade (CK+) dataset and the Toronto Face Dataset (TFD). We then qualitatively analyze the network by visualizing the spatial patterns that maximally excite different neurons in the convolutional layers and show how they resemble Facial Action Units (FAUs). Finally, we use the FAU labels provided in the CK+ dataset to verify that the FAUs observed in our filter visualizations indeed align with the subject's facial movements.
[ { "version": "v1", "created": "Sat, 10 Oct 2015 18:53:21 GMT" }, { "version": "v2", "created": "Fri, 28 Oct 2016 06:12:07 GMT" }, { "version": "v3", "created": "Thu, 16 Mar 2017 03:07:21 GMT" } ]
2017-03-17T00:00:00
[ [ "Khorrami", "Pooya", "" ], [ "Paine", "Tom Le", "" ], [ "Huang", "Thomas S.", "" ] ]
TITLE: Do Deep Neural Networks Learn Facial Action Units When Doing Expression Recognition? ABSTRACT: Despite being the appearance-based classifier of choice in recent years, relatively few works have examined how much convolutional neural networks (CNNs) can improve performance on accepted expression recognition benchmarks and, more importantly, examine what it is they actually learn. In this work, not only do we show that CNNs can achieve strong performance, but we also introduce an approach to decipher which portions of the face influence the CNN's predictions. First, we train a zero-bias CNN on facial expression data and achieve, to our knowledge, state-of-the-art performance on two expression recognition benchmarks: the extended Cohn-Kanade (CK+) dataset and the Toronto Face Dataset (TFD). We then qualitatively analyze the network by visualizing the spatial patterns that maximally excite different neurons in the convolutional layers and show how they resemble Facial Action Units (FAUs). Finally, we use the FAU labels provided in the CK+ dataset to verify that the FAUs observed in our filter visualizations indeed align with the subject's facial movements.
no_new_dataset
0.939582
1604.07513
Hirokatsu Kataoka
Teppei Suzuki, Soma Shirakabe, Yudai Miyashita, Akio Nakamura, Yutaka Satoh, Hirokatsu Kataoka
Semantic Change Detection with Hypermaps
null
null
null
null
cs.CV cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Change detection is the study of detecting changes between two different images of a scene taken at different times. By the detected change areas, however, a human cannot understand how different the two images. Therefore, a semantic understanding is required in the change detection research such as disaster investigation. The paper proposes the concept of semantic change detection, which involves intuitively inserting semantic meaning into detected change areas. We mainly focus on the novel semantic segmentation in addition to a conventional change detection approach. In order to solve this problem and obtain a high-level of performance, we propose an improvement to the hypercolumns representation, hereafter known as hypermaps, which effectively uses convolutional maps obtained from convolutional neural networks (CNNs). We also employ multi-scale feature representation captured by different image patches. We applied our method to the TSUNAMI Panoramic Change Detection dataset, and re-annotated the changed areas of the dataset via semantic classes. The results show that our multi-scale hypermaps provided outstanding performance on the re-annotated TSUNAMI dataset.
[ { "version": "v1", "created": "Tue, 26 Apr 2016 04:31:31 GMT" }, { "version": "v2", "created": "Thu, 16 Mar 2017 01:46:37 GMT" } ]
2017-03-17T00:00:00
[ [ "Suzuki", "Teppei", "" ], [ "Shirakabe", "Soma", "" ], [ "Miyashita", "Yudai", "" ], [ "Nakamura", "Akio", "" ], [ "Satoh", "Yutaka", "" ], [ "Kataoka", "Hirokatsu", "" ] ]
TITLE: Semantic Change Detection with Hypermaps ABSTRACT: Change detection is the study of detecting changes between two different images of a scene taken at different times. By the detected change areas, however, a human cannot understand how different the two images. Therefore, a semantic understanding is required in the change detection research such as disaster investigation. The paper proposes the concept of semantic change detection, which involves intuitively inserting semantic meaning into detected change areas. We mainly focus on the novel semantic segmentation in addition to a conventional change detection approach. In order to solve this problem and obtain a high-level of performance, we propose an improvement to the hypercolumns representation, hereafter known as hypermaps, which effectively uses convolutional maps obtained from convolutional neural networks (CNNs). We also employ multi-scale feature representation captured by different image patches. We applied our method to the TSUNAMI Panoramic Change Detection dataset, and re-annotated the changed areas of the dataset via semantic classes. The results show that our multi-scale hypermaps provided outstanding performance on the re-annotated TSUNAMI dataset.
no_new_dataset
0.951006
1607.03476
Paul Henderson
Paul Henderson, Vittorio Ferrari
End-to-end training of object class detectors for mean average precision
This version has minor additions to results (ablation study) and discussion
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a method for training CNN-based object class detectors directly using mean average precision (mAP) as the training loss, in a truly end-to-end fashion that includes non-maximum suppression (NMS) at training time. This contrasts with the traditional approach of training a CNN for a window classification loss, then applying NMS only at test time, when mAP is used as the evaluation metric in place of classification accuracy. However, mAP following NMS forms a piecewise-constant structured loss over thousands of windows, with gradients that do not convey useful information for gradient descent. Hence, we define new, general gradient-like quantities for piecewise constant functions, which have wide applicability. We describe how to calculate these efficiently for mAP following NMS, enabling to train a detector based on Fast R-CNN directly for mAP. This model achieves equivalent performance to the standard Fast R-CNN on the PASCAL VOC 2007 and 2012 datasets, while being conceptually more appealing as the very same model and loss are used at both training and test time.
[ { "version": "v1", "created": "Tue, 12 Jul 2016 19:45:12 GMT" }, { "version": "v2", "created": "Thu, 16 Mar 2017 13:55:07 GMT" } ]
2017-03-17T00:00:00
[ [ "Henderson", "Paul", "" ], [ "Ferrari", "Vittorio", "" ] ]
TITLE: End-to-end training of object class detectors for mean average precision ABSTRACT: We present a method for training CNN-based object class detectors directly using mean average precision (mAP) as the training loss, in a truly end-to-end fashion that includes non-maximum suppression (NMS) at training time. This contrasts with the traditional approach of training a CNN for a window classification loss, then applying NMS only at test time, when mAP is used as the evaluation metric in place of classification accuracy. However, mAP following NMS forms a piecewise-constant structured loss over thousands of windows, with gradients that do not convey useful information for gradient descent. Hence, we define new, general gradient-like quantities for piecewise constant functions, which have wide applicability. We describe how to calculate these efficiently for mAP following NMS, enabling to train a detector based on Fast R-CNN directly for mAP. This model achieves equivalent performance to the standard Fast R-CNN on the PASCAL VOC 2007 and 2012 datasets, while being conceptually more appealing as the very same model and loss are used at both training and test time.
no_new_dataset
0.952042
1608.03542
Daniel Hewlett
Daniel Hewlett, Alexandre Lacoste, Llion Jones, Illia Polosukhin, Andrew Fandrianto, Jay Han, Matthew Kelcey, David Berthelot
WikiReading: A Novel Large-scale Language Understanding Task over Wikipedia
null
Proceedings of the 54th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers), 2016, pp. 1535-1545
null
null
cs.CL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present WikiReading, a large-scale natural language understanding task and publicly-available dataset with 18 million instances. The task is to predict textual values from the structured knowledge base Wikidata by reading the text of the corresponding Wikipedia articles. The task contains a rich variety of challenging classification and extraction sub-tasks, making it well-suited for end-to-end models such as deep neural networks (DNNs). We compare various state-of-the-art DNN-based architectures for document classification, information extraction, and question answering. We find that models supporting a rich answer space, such as word or character sequences, perform best. Our best-performing model, a word-level sequence to sequence model with a mechanism to copy out-of-vocabulary words, obtains an accuracy of 71.8%.
[ { "version": "v1", "created": "Thu, 11 Aug 2016 17:34:12 GMT" }, { "version": "v2", "created": "Wed, 15 Mar 2017 19:58:44 GMT" } ]
2017-03-17T00:00:00
[ [ "Hewlett", "Daniel", "" ], [ "Lacoste", "Alexandre", "" ], [ "Jones", "Llion", "" ], [ "Polosukhin", "Illia", "" ], [ "Fandrianto", "Andrew", "" ], [ "Han", "Jay", "" ], [ "Kelcey", "Matthew", "" ], [ "Berthelot", "David", "" ] ]
TITLE: WikiReading: A Novel Large-scale Language Understanding Task over Wikipedia ABSTRACT: We present WikiReading, a large-scale natural language understanding task and publicly-available dataset with 18 million instances. The task is to predict textual values from the structured knowledge base Wikidata by reading the text of the corresponding Wikipedia articles. The task contains a rich variety of challenging classification and extraction sub-tasks, making it well-suited for end-to-end models such as deep neural networks (DNNs). We compare various state-of-the-art DNN-based architectures for document classification, information extraction, and question answering. We find that models supporting a rich answer space, such as word or character sequences, perform best. Our best-performing model, a word-level sequence to sequence model with a mechanism to copy out-of-vocabulary words, obtains an accuracy of 71.8%.
new_dataset
0.960842
1612.07597
Andreas Henelius
Andreas Henelius, Antti Ukkonen, Kai Puolam\"aki
Finding Statistically Significant Attribute Interactions
9 pages, 4 tables, 1 figure
null
null
null
stat.ML cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In many data exploration tasks it is meaningful to identify groups of attribute interactions that are specific to a variable of interest. For instance, in a dataset where the attributes are medical markers and the variable of interest (class variable) is binary indicating presence/absence of disease, we would like to know which medical markers interact with respect to the binary class label. These interactions are useful in several practical applications, for example, to gain insight into the structure of the data, in feature selection, and in data anonymisation. We present a novel method, based on statistical significance testing, that can be used to verify if the data set has been created by a given factorised class-conditional joint distribution, where the distribution is parametrised by a partition of its attributes. Furthermore, we provide a method, named ASTRID, for automatically finding a partition of attributes describing the distribution that has generated the data. State-of-the-art classifiers are utilised to capture the interactions present in the data by systematically breaking attribute interactions and observing the effect of this breaking on classifier performance. We empirically demonstrate the utility of the proposed method with examples using real and synthetic data.
[ { "version": "v1", "created": "Thu, 22 Dec 2016 13:53:42 GMT" }, { "version": "v2", "created": "Thu, 16 Mar 2017 12:21:36 GMT" } ]
2017-03-17T00:00:00
[ [ "Henelius", "Andreas", "" ], [ "Ukkonen", "Antti", "" ], [ "Puolamäki", "Kai", "" ] ]
TITLE: Finding Statistically Significant Attribute Interactions ABSTRACT: In many data exploration tasks it is meaningful to identify groups of attribute interactions that are specific to a variable of interest. For instance, in a dataset where the attributes are medical markers and the variable of interest (class variable) is binary indicating presence/absence of disease, we would like to know which medical markers interact with respect to the binary class label. These interactions are useful in several practical applications, for example, to gain insight into the structure of the data, in feature selection, and in data anonymisation. We present a novel method, based on statistical significance testing, that can be used to verify if the data set has been created by a given factorised class-conditional joint distribution, where the distribution is parametrised by a partition of its attributes. Furthermore, we provide a method, named ASTRID, for automatically finding a partition of attributes describing the distribution that has generated the data. State-of-the-art classifiers are utilised to capture the interactions present in the data by systematically breaking attribute interactions and observing the effect of this breaking on classifier performance. We empirically demonstrate the utility of the proposed method with examples using real and synthetic data.
no_new_dataset
0.945349
1702.02628
Amin Ghafouri
Amin Ghafouri, Aron Laszka, Abhishek Dubey, and Xenofon Koutsoukos
Optimal Detection of Faulty Traffic Sensors Used in Route Planning
Proceedings of The 2nd Workshop on Science of Smart City Operations and Platforms Engineering (SCOPE 2017), Pittsburgh, PA USA, April 2017, 6 pages
null
10.1145/3063386.3063767
null
cs.AI cs.SY
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In a smart city, real-time traffic sensors may be deployed for various applications, such as route planning. Unfortunately, sensors are prone to failures, which result in erroneous traffic data. Erroneous data can adversely affect applications such as route planning, and can cause increased travel time. To minimize the impact of sensor failures, we must detect them promptly and accurately. However, typical detection algorithms may lead to a large number of false positives (i.e., false alarms) and false negatives (i.e., missed detections), which can result in suboptimal route planning. In this paper, we devise an effective detector for identifying faulty traffic sensors using a prediction model based on Gaussian Processes. Further, we present an approach for computing the optimal parameters of the detector which minimize losses due to false-positive and false-negative errors. We also characterize critical sensors, whose failure can have high impact on the route planning application. Finally, we implement our method and evaluate it numerically using a real-world dataset and the route planning platform OpenTripPlanner.
[ { "version": "v1", "created": "Wed, 8 Feb 2017 21:49:46 GMT" }, { "version": "v2", "created": "Thu, 16 Mar 2017 16:37:47 GMT" } ]
2017-03-17T00:00:00
[ [ "Ghafouri", "Amin", "" ], [ "Laszka", "Aron", "" ], [ "Dubey", "Abhishek", "" ], [ "Koutsoukos", "Xenofon", "" ] ]
TITLE: Optimal Detection of Faulty Traffic Sensors Used in Route Planning ABSTRACT: In a smart city, real-time traffic sensors may be deployed for various applications, such as route planning. Unfortunately, sensors are prone to failures, which result in erroneous traffic data. Erroneous data can adversely affect applications such as route planning, and can cause increased travel time. To minimize the impact of sensor failures, we must detect them promptly and accurately. However, typical detection algorithms may lead to a large number of false positives (i.e., false alarms) and false negatives (i.e., missed detections), which can result in suboptimal route planning. In this paper, we devise an effective detector for identifying faulty traffic sensors using a prediction model based on Gaussian Processes. Further, we present an approach for computing the optimal parameters of the detector which minimize losses due to false-positive and false-negative errors. We also characterize critical sensors, whose failure can have high impact on the route planning application. Finally, we implement our method and evaluate it numerically using a real-world dataset and the route planning platform OpenTripPlanner.
no_new_dataset
0.951818
1703.04103
Grigorios Kalliatakis M.A.
Grigorios Kalliatakis, Shoaib Ehsan, Maria Fasli, Ales Leonardis, Juergen Gall and Klaus D. McDonald-Maier
Detection of Human Rights Violations in Images: Can Convolutional Neural Networks help?
In Proceedings of the 12th International Conference on Computer Vision Theory and Applications (VISAPP 2017), 8 pages
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
After setting the performance benchmarks for image, video, speech and audio processing, deep convolutional networks have been core to the greatest advances in image recognition tasks in recent times. This raises the question of whether there are any benefit in targeting these remarkable deep architectures with the unattempted task of recognising human rights violations through digital images. Under this perspective, we introduce a new, well-sampled human rights-centric dataset called Human Rights Understanding (HRUN). We conduct a rigorous evaluation on a common ground by combining this dataset with different state-of-the-art deep convolutional architectures in order to achieve recognition of human rights violations. Experimental results on the HRUN dataset have shown that the best performing CNN architectures can achieve up to 88.10\% mean average precision. Additionally, our experiments demonstrate that increasing the size of the training samples is crucial for achieving an improvement on mean average precision principally when utilising very deep networks.
[ { "version": "v1", "created": "Sun, 12 Mar 2017 11:39:41 GMT" }, { "version": "v2", "created": "Thu, 16 Mar 2017 10:37:25 GMT" } ]
2017-03-17T00:00:00
[ [ "Kalliatakis", "Grigorios", "" ], [ "Ehsan", "Shoaib", "" ], [ "Fasli", "Maria", "" ], [ "Leonardis", "Ales", "" ], [ "Gall", "Juergen", "" ], [ "McDonald-Maier", "Klaus D.", "" ] ]
TITLE: Detection of Human Rights Violations in Images: Can Convolutional Neural Networks help? ABSTRACT: After setting the performance benchmarks for image, video, speech and audio processing, deep convolutional networks have been core to the greatest advances in image recognition tasks in recent times. This raises the question of whether there are any benefit in targeting these remarkable deep architectures with the unattempted task of recognising human rights violations through digital images. Under this perspective, we introduce a new, well-sampled human rights-centric dataset called Human Rights Understanding (HRUN). We conduct a rigorous evaluation on a common ground by combining this dataset with different state-of-the-art deep convolutional architectures in order to achieve recognition of human rights violations. Experimental results on the HRUN dataset have shown that the best performing CNN architectures can achieve up to 88.10\% mean average precision. Additionally, our experiments demonstrate that increasing the size of the training samples is crucial for achieving an improvement on mean average precision principally when utilising very deep networks.
new_dataset
0.964888
1703.04215
Jinliang Xu
Jinliang Xu, Shangguang Wang, Fangchun Yang, Jie Tang
Multiple User Context Inference by Fusing Data Sources
This paper has been withdrawn by the author due to a crucial sign error in some equations and figures
null
null
null
cs.IR cs.DC
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Inference of user context information, including user's gender, age, marital status, location and so on, has been proven to be valuable for building context aware recommender system. However, prevalent existing studies on user context inference have two shortcommings: 1. focusing on only a single data source (e.g. Internet browsing logs, or mobile call records), and 2. ignoring the interdependence of multiple user contexts (e.g. interdependence between age and marital status), which have led to poor inference performance. To solve this problem, in this paper, we first exploit tensor outer product to fuse multiple data sources in the feature space to obtain an extensional user feature representation. Following this, by taking this extensional user feature representation as input, we propose a multiple attribute probabilistic model called MulAProM to infer user contexts that can take advantage of the interdependence between them. Our study is based on large telecommunication datasets from the local mobile operator of Shanghai, China, and consists of two data sources, 4.6 million call detail records and 7.5 million data traffic records of 8,000 mobile users, collected in the course of six months. The experimental results show that our model can outperform other models in terms of \emph{recall}, \emph{precision}, and the \emph{F1-measure}.
[ { "version": "v1", "created": "Mon, 13 Mar 2017 01:23:17 GMT" }, { "version": "v2", "created": "Thu, 16 Mar 2017 15:06:20 GMT" } ]
2017-03-17T00:00:00
[ [ "Xu", "Jinliang", "" ], [ "Wang", "Shangguang", "" ], [ "Yang", "Fangchun", "" ], [ "Tang", "Jie", "" ] ]
TITLE: Multiple User Context Inference by Fusing Data Sources ABSTRACT: Inference of user context information, including user's gender, age, marital status, location and so on, has been proven to be valuable for building context aware recommender system. However, prevalent existing studies on user context inference have two shortcommings: 1. focusing on only a single data source (e.g. Internet browsing logs, or mobile call records), and 2. ignoring the interdependence of multiple user contexts (e.g. interdependence between age and marital status), which have led to poor inference performance. To solve this problem, in this paper, we first exploit tensor outer product to fuse multiple data sources in the feature space to obtain an extensional user feature representation. Following this, by taking this extensional user feature representation as input, we propose a multiple attribute probabilistic model called MulAProM to infer user contexts that can take advantage of the interdependence between them. Our study is based on large telecommunication datasets from the local mobile operator of Shanghai, China, and consists of two data sources, 4.6 million call detail records and 7.5 million data traffic records of 8,000 mobile users, collected in the course of six months. The experimental results show that our model can outperform other models in terms of \emph{recall}, \emph{precision}, and the \emph{F1-measure}.
no_new_dataset
0.947527
1703.04216
Jinliang Xu
Jinliang Xu, Shangguang Wang, Fangchun Yang, Rong N. Chang
Cognitive Inference of Demographic Data by User Ratings
This paper has been withdrawn by the author due to a crucial sign error in some equations and figures
null
null
null
cs.IR cs.DC
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Cognitive inference of user demographics, such as gender and age, plays an important role in creating user profiles for adjusting marketing strategies and generating personalized recommendations because user demographic data is usually not available due to data privacy concerns. At present, users can readily express feedback regarding products or services that they have purchased. During this process, user demographics are concealed, but the data has never yet been successfully utilized to contribute to the cognitive inference of user demographics. In this paper, we investigate the inference power of user ratings data, and propose a simple yet general cognitive inference model, called rating to profile (R2P), to infer user demographics from user provided ratings. In particular, the proposed R2P model can achieve the following: 1. Correctly integrate user ratings into model training. 2.Infer multiple demographic attributes of users simultaneously, capturing the underlying relevance between different demographic attributes. 3. Train its two components, i.e. feature extractor and classifier, in an integrated manner under a supervised learning paradigm, which effectively helps to discover useful hidden patterns from highly sparse ratings data. We introduce how to incorporate user ratings data into the research field of cognitive inference of user demographic data, and detail the model development and optimization process for the proposed R2P. Extensive experiments are conducted on two real-world ratings datasets against various compared state-of-the-art methods, and the results from multiple aspects demonstrate that our proposed R2P model can significantly improve on the cognitive inference performance of user demographic data.
[ { "version": "v1", "created": "Mon, 13 Mar 2017 01:23:31 GMT" }, { "version": "v2", "created": "Thu, 16 Mar 2017 15:07:33 GMT" } ]
2017-03-17T00:00:00
[ [ "Xu", "Jinliang", "" ], [ "Wang", "Shangguang", "" ], [ "Yang", "Fangchun", "" ], [ "Chang", "Rong N.", "" ] ]
TITLE: Cognitive Inference of Demographic Data by User Ratings ABSTRACT: Cognitive inference of user demographics, such as gender and age, plays an important role in creating user profiles for adjusting marketing strategies and generating personalized recommendations because user demographic data is usually not available due to data privacy concerns. At present, users can readily express feedback regarding products or services that they have purchased. During this process, user demographics are concealed, but the data has never yet been successfully utilized to contribute to the cognitive inference of user demographics. In this paper, we investigate the inference power of user ratings data, and propose a simple yet general cognitive inference model, called rating to profile (R2P), to infer user demographics from user provided ratings. In particular, the proposed R2P model can achieve the following: 1. Correctly integrate user ratings into model training. 2.Infer multiple demographic attributes of users simultaneously, capturing the underlying relevance between different demographic attributes. 3. Train its two components, i.e. feature extractor and classifier, in an integrated manner under a supervised learning paradigm, which effectively helps to discover useful hidden patterns from highly sparse ratings data. We introduce how to incorporate user ratings data into the research field of cognitive inference of user demographic data, and detail the model development and optimization process for the proposed R2P. Extensive experiments are conducted on two real-world ratings datasets against various compared state-of-the-art methods, and the results from multiple aspects demonstrate that our proposed R2P model can significantly improve on the cognitive inference performance of user demographic data.
no_new_dataset
0.943712
1703.05400
Shin-Ming Cheng
Shin-Ming Cheng and Pin-Yu Chen and Ching-Chao Lin and Hsu-Chun Hsiao
Traffic-aware Patching for Cyber Security in Mobile IoT
8 pages, 6 figures, To appear in July 2017 IEEE Communications Magazine, feature topic on "Traffic Measurements for Cyber Security"
null
null
null
cs.CR
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The various types of communication technologies and mobility features in Internet of Things (IoT) on the one hand enable fruitful and attractive applications, but on the other hand facilitates malware propagation, thereby raising new challenges on handling IoT-empowered malware for cyber security. Comparing with the malware propagation control scheme in traditional wireless networks where nodes can be directly repaired and secured, in IoT, compromised end devices are difficult to be patched. Alternatively, blocking malware via patching intermediate nodes turns out to be a more feasible and practical solution. Specifically, patching intermediate nodes can effectively prevent the proliferation of malware propagation by securing infrastructure links and limiting malware propagation to local device-to-device dissemination. This article proposes a novel traffic-aware patching scheme to select important intermediate nodes to patch, which applies to the IoT system with limited patching resources and response time constraint. Experiments on real-world trace datasets in IoT networks are conducted to demonstrate the advantage of the proposed traffic-aware patching scheme in alleviating malware propagation.
[ { "version": "v1", "created": "Wed, 15 Mar 2017 21:59:05 GMT" } ]
2017-03-17T00:00:00
[ [ "Cheng", "Shin-Ming", "" ], [ "Chen", "Pin-Yu", "" ], [ "Lin", "Ching-Chao", "" ], [ "Hsiao", "Hsu-Chun", "" ] ]
TITLE: Traffic-aware Patching for Cyber Security in Mobile IoT ABSTRACT: The various types of communication technologies and mobility features in Internet of Things (IoT) on the one hand enable fruitful and attractive applications, but on the other hand facilitates malware propagation, thereby raising new challenges on handling IoT-empowered malware for cyber security. Comparing with the malware propagation control scheme in traditional wireless networks where nodes can be directly repaired and secured, in IoT, compromised end devices are difficult to be patched. Alternatively, blocking malware via patching intermediate nodes turns out to be a more feasible and practical solution. Specifically, patching intermediate nodes can effectively prevent the proliferation of malware propagation by securing infrastructure links and limiting malware propagation to local device-to-device dissemination. This article proposes a novel traffic-aware patching scheme to select important intermediate nodes to patch, which applies to the IoT system with limited patching resources and response time constraint. Experiments on real-world trace datasets in IoT networks are conducted to demonstrate the advantage of the proposed traffic-aware patching scheme in alleviating malware propagation.
no_new_dataset
0.945298
1703.05411
Tien Thanh Nguyen
Tien Thanh Nguyen, Xuan Cuong Pham, Alan Wee-Chung Liew, Witold Pedrycz
Aggregation of Classifiers: A Justifiable Information Granularity Approach
33 pages, 3 figures
null
null
null
cs.LG stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this study, we introduce a new approach to combine multi-classifiers in an ensemble system. Instead of using numeric membership values encountered in fixed combining rules, we construct interval membership values associated with each class prediction at the level of meta-data of observation by using concepts of information granules. In the proposed method, uncertainty (diversity) of findings produced by the base classifiers is quantified by interval-based information granules. The discriminative decision model is generated by considering both the bounds and the length of the obtained intervals. We select ten and then fifteen learning algorithms to build a heterogeneous ensemble system and then conducted the experiment on a number of UCI datasets. The experimental results demonstrate that the proposed approach performs better than the benchmark algorithms including six fixed combining methods, one trainable combining method, AdaBoost, Bagging, and Random Subspace.
[ { "version": "v1", "created": "Wed, 15 Mar 2017 22:48:05 GMT" } ]
2017-03-17T00:00:00
[ [ "Nguyen", "Tien Thanh", "" ], [ "Pham", "Xuan Cuong", "" ], [ "Liew", "Alan Wee-Chung", "" ], [ "Pedrycz", "Witold", "" ] ]
TITLE: Aggregation of Classifiers: A Justifiable Information Granularity Approach ABSTRACT: In this study, we introduce a new approach to combine multi-classifiers in an ensemble system. Instead of using numeric membership values encountered in fixed combining rules, we construct interval membership values associated with each class prediction at the level of meta-data of observation by using concepts of information granules. In the proposed method, uncertainty (diversity) of findings produced by the base classifiers is quantified by interval-based information granules. The discriminative decision model is generated by considering both the bounds and the length of the obtained intervals. We select ten and then fifteen learning algorithms to build a heterogeneous ensemble system and then conducted the experiment on a number of UCI datasets. The experimental results demonstrate that the proposed approach performs better than the benchmark algorithms including six fixed combining methods, one trainable combining method, AdaBoost, Bagging, and Random Subspace.
no_new_dataset
0.951459
1703.05422
Travis Desell
Travis Desell
Large Scale Evolution of Convolutional Neural Networks Using Volunteer Computing
17 pages, 13 figures. Submitted to the 2017 Genetic and Evolutionary Computation Conference (GECCO 2017)
null
null
null
cs.NE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This work presents a new algorithm called evolutionary exploration of augmenting convolutional topologies (EXACT), which is capable of evolving the structure of convolutional neural networks (CNNs). EXACT is in part modeled after the neuroevolution of augmenting topologies (NEAT) algorithm, with notable exceptions to allow it to scale to large scale distributed computing environments and evolve networks with convolutional filters. In addition to multithreaded and MPI versions, EXACT has been implemented as part of a BOINC volunteer computing project, allowing large scale evolution. During a period of two months, over 4,500 volunteered computers on the Citizen Science Grid trained over 120,000 CNNs and evolved networks reaching 98.32% test data accuracy on the MNIST handwritten digits dataset. These results are even stronger as the backpropagation strategy used to train the CNNs was fairly rudimentary (ReLU units, L2 regularization and Nesterov momentum) and these were initial test runs done without refinement of the backpropagation hyperparameters. Further, the EXACT evolutionary strategy is independent of the method used to train the CNNs, so they could be further improved by advanced techniques like elastic distortions, pretraining and dropout. The evolved networks are also quite interesting, showing "organic" structures and significant differences from standard human designed architectures.
[ { "version": "v1", "created": "Wed, 15 Mar 2017 23:17:24 GMT" } ]
2017-03-17T00:00:00
[ [ "Desell", "Travis", "" ] ]
TITLE: Large Scale Evolution of Convolutional Neural Networks Using Volunteer Computing ABSTRACT: This work presents a new algorithm called evolutionary exploration of augmenting convolutional topologies (EXACT), which is capable of evolving the structure of convolutional neural networks (CNNs). EXACT is in part modeled after the neuroevolution of augmenting topologies (NEAT) algorithm, with notable exceptions to allow it to scale to large scale distributed computing environments and evolve networks with convolutional filters. In addition to multithreaded and MPI versions, EXACT has been implemented as part of a BOINC volunteer computing project, allowing large scale evolution. During a period of two months, over 4,500 volunteered computers on the Citizen Science Grid trained over 120,000 CNNs and evolved networks reaching 98.32% test data accuracy on the MNIST handwritten digits dataset. These results are even stronger as the backpropagation strategy used to train the CNNs was fairly rudimentary (ReLU units, L2 regularization and Nesterov momentum) and these were initial test runs done without refinement of the backpropagation hyperparameters. Further, the EXACT evolutionary strategy is independent of the method used to train the CNNs, so they could be further improved by advanced techniques like elastic distortions, pretraining and dropout. The evolved networks are also quite interesting, showing "organic" structures and significant differences from standard human designed architectures.
no_new_dataset
0.949059
1703.05423
Florian Strub
Florian Strub and Harm de Vries and Jeremie Mary and Bilal Piot and Aaron Courville and Olivier Pietquin
End-to-end optimization of goal-driven and visually grounded dialogue systems
null
null
null
null
cs.CL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
End-to-end design of dialogue systems has recently become a popular research topic thanks to powerful tools such as encoder-decoder architectures for sequence-to-sequence learning. Yet, most current approaches cast human-machine dialogue management as a supervised learning problem, aiming at predicting the next utterance of a participant given the full history of the dialogue. This vision is too simplistic to render the intrinsic planning problem inherent to dialogue as well as its grounded nature, making the context of a dialogue larger than the sole history. This is why only chit-chat and question answering tasks have been addressed so far using end-to-end architectures. In this paper, we introduce a Deep Reinforcement Learning method to optimize visually grounded task-oriented dialogues, based on the policy gradient algorithm. This approach is tested on a dataset of 120k dialogues collected through Mechanical Turk and provides encouraging results at solving both the problem of generating natural dialogues and the task of discovering a specific object in a complex picture.
[ { "version": "v1", "created": "Wed, 15 Mar 2017 23:34:20 GMT" } ]
2017-03-17T00:00:00
[ [ "Strub", "Florian", "" ], [ "de Vries", "Harm", "" ], [ "Mary", "Jeremie", "" ], [ "Piot", "Bilal", "" ], [ "Courville", "Aaron", "" ], [ "Pietquin", "Olivier", "" ] ]
TITLE: End-to-end optimization of goal-driven and visually grounded dialogue systems ABSTRACT: End-to-end design of dialogue systems has recently become a popular research topic thanks to powerful tools such as encoder-decoder architectures for sequence-to-sequence learning. Yet, most current approaches cast human-machine dialogue management as a supervised learning problem, aiming at predicting the next utterance of a participant given the full history of the dialogue. This vision is too simplistic to render the intrinsic planning problem inherent to dialogue as well as its grounded nature, making the context of a dialogue larger than the sole history. This is why only chit-chat and question answering tasks have been addressed so far using end-to-end architectures. In this paper, we introduce a Deep Reinforcement Learning method to optimize visually grounded task-oriented dialogues, based on the policy gradient algorithm. This approach is tested on a dataset of 120k dialogues collected through Mechanical Turk and provides encouraging results at solving both the problem of generating natural dialogues and the task of discovering a specific object in a complex picture.
no_new_dataset
0.937326
1703.05530
Vincent Andrearczyk
Vincent Andrearczyk and Paul F. Whelan
Convolutional Neural Network on Three Orthogonal Planes for Dynamic Texture Classification
19 pages, 10 figures
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Dynamic Textures (DTs) are sequences of images of moving scenes that exhibit certain stationarity properties in time such as smoke, vegetation and fire. The analysis of DT is important for recognition, segmentation, synthesis or retrieval for a range of applications including surveillance, medical imaging and remote sensing. Deep learning methods have shown impressive results and are now the new state of the art for a wide range of computer vision tasks including image and video recognition and segmentation. In particular, Convolutional Neural Networks (CNNs) have recently proven to be well suited for texture analysis with a design similar to a filter bank approach. In this paper, we develop a new approach to DT analysis based on a CNN method applied on three orthogonal planes x y , xt and y t . We train CNNs on spatial frames and temporal slices extracted from the DT sequences and combine their outputs to obtain a competitive DT classifier. Our results on a wide range of commonly used DT classification benchmark datasets prove the robustness of our approach. Significant improvement of the state of the art is shown on the larger datasets.
[ { "version": "v1", "created": "Thu, 16 Mar 2017 09:30:07 GMT" } ]
2017-03-17T00:00:00
[ [ "Andrearczyk", "Vincent", "" ], [ "Whelan", "Paul F.", "" ] ]
TITLE: Convolutional Neural Network on Three Orthogonal Planes for Dynamic Texture Classification ABSTRACT: Dynamic Textures (DTs) are sequences of images of moving scenes that exhibit certain stationarity properties in time such as smoke, vegetation and fire. The analysis of DT is important for recognition, segmentation, synthesis or retrieval for a range of applications including surveillance, medical imaging and remote sensing. Deep learning methods have shown impressive results and are now the new state of the art for a wide range of computer vision tasks including image and video recognition and segmentation. In particular, Convolutional Neural Networks (CNNs) have recently proven to be well suited for texture analysis with a design similar to a filter bank approach. In this paper, we develop a new approach to DT analysis based on a CNN method applied on three orthogonal planes x y , xt and y t . We train CNNs on spatial frames and temporal slices extracted from the DT sequences and combine their outputs to obtain a competitive DT classifier. Our results on a wide range of commonly used DT classification benchmark datasets prove the robustness of our approach. Significant improvement of the state of the art is shown on the larger datasets.
no_new_dataset
0.955236
1703.05584
Mohammad Azzeh
Mohammad Azzeh
Software effort estimation based on optimized model tree
null
null
null
null
cs.SE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Background: It is widely recognized that software effort estimation is a regression problem. Model Tree (MT) is one of the Machine Learning based regression techniques that is useful for software effort estimation, but as other machine learning algorithms, the MT has a large space of configuration and requires to carefully setting its parameters. The choice of such parameters is a dataset dependent so no general guideline can govern this process which forms the motivation of this work. Aims: This study investigates the effect of using the most recent optimization algorithm called Bees algorithm to specify the optimal choice of MT parameters that fit a dataset and therefore improve prediction accuracy. Method: We used MT with optimal parameters identified by the Bees algorithm to construct software effort estimation model. The model has been validated over eight datasets come from two main sources: PROMISE and ISBSG. Also we used 3-Fold cross validation to empirically assess the prediction accuracies of different estimation models. As benchmark, results are also compared to those obtained with Stepwise Regression Case-Based Reasoning and Multi-Layer Perceptron. Results: The results obtained from combination of MT and Bees algorithm are encouraging and outperforms other well-known estimation methods applied on employed datasets. They are also interesting enough to suggest the effectiveness of MT among the techniques that are suitable for effort estimation. Conclusions: The use of the Bees algorithm enabled us to automatically find optimal MT parameters required to construct effort estimation models that fit each individual dataset. Also it provided a significant improvement on prediction accuracy.
[ { "version": "v1", "created": "Mon, 13 Mar 2017 18:23:55 GMT" } ]
2017-03-17T00:00:00
[ [ "Azzeh", "Mohammad", "" ] ]
TITLE: Software effort estimation based on optimized model tree ABSTRACT: Background: It is widely recognized that software effort estimation is a regression problem. Model Tree (MT) is one of the Machine Learning based regression techniques that is useful for software effort estimation, but as other machine learning algorithms, the MT has a large space of configuration and requires to carefully setting its parameters. The choice of such parameters is a dataset dependent so no general guideline can govern this process which forms the motivation of this work. Aims: This study investigates the effect of using the most recent optimization algorithm called Bees algorithm to specify the optimal choice of MT parameters that fit a dataset and therefore improve prediction accuracy. Method: We used MT with optimal parameters identified by the Bees algorithm to construct software effort estimation model. The model has been validated over eight datasets come from two main sources: PROMISE and ISBSG. Also we used 3-Fold cross validation to empirically assess the prediction accuracies of different estimation models. As benchmark, results are also compared to those obtained with Stepwise Regression Case-Based Reasoning and Multi-Layer Perceptron. Results: The results obtained from combination of MT and Bees algorithm are encouraging and outperforms other well-known estimation methods applied on employed datasets. They are also interesting enough to suggest the effectiveness of MT among the techniques that are suitable for effort estimation. Conclusions: The use of the Bees algorithm enabled us to automatically find optimal MT parameters required to construct effort estimation models that fit each individual dataset. Also it provided a significant improvement on prediction accuracy.
no_new_dataset
0.9463
1703.05605
Li Liu
Li Liu, Fumin Shen, Yuming Shen, Xianglong Liu, and Ling Shao
Deep Sketch Hashing: Fast Free-hand Sketch-Based Image Retrieval
This paper will appear as a spotlight paper in CVPR2017
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Free-hand sketch-based image retrieval (SBIR) is a specific cross-view retrieval task, in which queries are abstract and ambiguous sketches while the retrieval database is formed with natural images. Work in this area mainly focuses on extracting representative and shared features for sketches and natural images. However, these can neither cope well with the geometric distortion between sketches and images nor be feasible for large-scale SBIR due to the heavy continuous-valued distance computation. In this paper, we speed up SBIR by introducing a novel binary coding method, named \textbf{Deep Sketch Hashing} (DSH), where a semi-heterogeneous deep architecture is proposed and incorporated into an end-to-end binary coding framework. Specifically, three convolutional neural networks are utilized to encode free-hand sketches, natural images and, especially, the auxiliary sketch-tokens which are adopted as bridges to mitigate the sketch-image geometric distortion. The learned DSH codes can effectively capture the cross-view similarities as well as the intrinsic semantic correlations between different categories. To the best of our knowledge, DSH is the first hashing work specifically designed for category-level SBIR with an end-to-end deep architecture. The proposed DSH is comprehensively evaluated on two large-scale datasets of TU-Berlin Extension and Sketchy, and the experiments consistently show DSH's superior SBIR accuracies over several state-of-the-art methods, while achieving significantly reduced retrieval time and memory footprint.
[ { "version": "v1", "created": "Thu, 16 Mar 2017 13:18:36 GMT" } ]
2017-03-17T00:00:00
[ [ "Liu", "Li", "" ], [ "Shen", "Fumin", "" ], [ "Shen", "Yuming", "" ], [ "Liu", "Xianglong", "" ], [ "Shao", "Ling", "" ] ]
TITLE: Deep Sketch Hashing: Fast Free-hand Sketch-Based Image Retrieval ABSTRACT: Free-hand sketch-based image retrieval (SBIR) is a specific cross-view retrieval task, in which queries are abstract and ambiguous sketches while the retrieval database is formed with natural images. Work in this area mainly focuses on extracting representative and shared features for sketches and natural images. However, these can neither cope well with the geometric distortion between sketches and images nor be feasible for large-scale SBIR due to the heavy continuous-valued distance computation. In this paper, we speed up SBIR by introducing a novel binary coding method, named \textbf{Deep Sketch Hashing} (DSH), where a semi-heterogeneous deep architecture is proposed and incorporated into an end-to-end binary coding framework. Specifically, three convolutional neural networks are utilized to encode free-hand sketches, natural images and, especially, the auxiliary sketch-tokens which are adopted as bridges to mitigate the sketch-image geometric distortion. The learned DSH codes can effectively capture the cross-view similarities as well as the intrinsic semantic correlations between different categories. To the best of our knowledge, DSH is the first hashing work specifically designed for category-level SBIR with an end-to-end deep architecture. The proposed DSH is comprehensively evaluated on two large-scale datasets of TU-Berlin Extension and Sketchy, and the experiments consistently show DSH's superior SBIR accuracies over several state-of-the-art methods, while achieving significantly reduced retrieval time and memory footprint.
no_new_dataset
0.946941
1703.05724
Sailesh Conjeti
Sailesh Conjeti, Magdalini Paschali, Amin Katouzian and Nassir Navab
Learning Robust Hash Codes for Multiple Instance Image Retrieval
10 pages, 7 figures, under review at MICCAI 2017
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, for the first time, we introduce a multiple instance (MI) deep hashing technique for learning discriminative hash codes with weak bag-level supervision suited for large-scale retrieval. We learn such hash codes by aggregating deeply learnt hierarchical representations across bag members through a dedicated MI pool layer. For better trainability and retrieval quality, we propose a two-pronged approach that includes robust optimization and training with an auxiliary single instance hashing arm which is down-regulated gradually. We pose retrieval for tumor assessment as an MI problem because tumors often coexist with benign masses and could exhibit complementary signatures when scanned from different anatomical views. Experimental validations on benchmark mammography and histology datasets demonstrate improved retrieval performance over the state-of-the-art methods.
[ { "version": "v1", "created": "Thu, 16 Mar 2017 17:07:26 GMT" } ]
2017-03-17T00:00:00
[ [ "Conjeti", "Sailesh", "" ], [ "Paschali", "Magdalini", "" ], [ "Katouzian", "Amin", "" ], [ "Navab", "Nassir", "" ] ]
TITLE: Learning Robust Hash Codes for Multiple Instance Image Retrieval ABSTRACT: In this paper, for the first time, we introduce a multiple instance (MI) deep hashing technique for learning discriminative hash codes with weak bag-level supervision suited for large-scale retrieval. We learn such hash codes by aggregating deeply learnt hierarchical representations across bag members through a dedicated MI pool layer. For better trainability and retrieval quality, we propose a two-pronged approach that includes robust optimization and training with an auxiliary single instance hashing arm which is down-regulated gradually. We pose retrieval for tumor assessment as an MI problem because tumors often coexist with benign masses and could exhibit complementary signatures when scanned from different anatomical views. Experimental validations on benchmark mammography and histology datasets demonstrate improved retrieval performance over the state-of-the-art methods.
no_new_dataset
0.945197
1312.2923
Adam Sykulski Dr
Adam M. Sykulski, Sofia C. Olhede, Jonathan M. Lilly, Eric Danioux
Lagrangian Time Series Models for Ocean Surface Drifter Trajectories
21 pages, 10 figures
Journal of the Royal Statistical Society (Series C, Applied Statistics), 65(1), 29-50, 2016
10.1111/rssc.12112
null
stat.AP physics.ao-ph physics.flu-dyn stat.ME
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper proposes stochastic models for the analysis of ocean surface trajectories obtained from freely-drifting satellite-tracked instruments. The proposed time series models are used to summarise large multivariate datasets and infer important physical parameters of inertial oscillations and other ocean processes. Nonstationary time series methods are employed to account for the spatiotemporal variability of each trajectory. Because the datasets are large, we construct computationally efficient methods through the use of frequency-domain modelling and estimation, with the data expressed as complex-valued time series. We detail how practical issues related to sampling and model misspecification may be addressed using semi-parametric techniques for time series, and we demonstrate the effectiveness of our stochastic models through application to both real-world data and to numerical model output.
[ { "version": "v1", "created": "Tue, 10 Dec 2013 19:34:43 GMT" }, { "version": "v2", "created": "Wed, 18 Mar 2015 22:44:56 GMT" }, { "version": "v3", "created": "Wed, 22 Apr 2015 00:05:09 GMT" } ]
2017-03-16T00:00:00
[ [ "Sykulski", "Adam M.", "" ], [ "Olhede", "Sofia C.", "" ], [ "Lilly", "Jonathan M.", "" ], [ "Danioux", "Eric", "" ] ]
TITLE: Lagrangian Time Series Models for Ocean Surface Drifter Trajectories ABSTRACT: This paper proposes stochastic models for the analysis of ocean surface trajectories obtained from freely-drifting satellite-tracked instruments. The proposed time series models are used to summarise large multivariate datasets and infer important physical parameters of inertial oscillations and other ocean processes. Nonstationary time series methods are employed to account for the spatiotemporal variability of each trajectory. Because the datasets are large, we construct computationally efficient methods through the use of frequency-domain modelling and estimation, with the data expressed as complex-valued time series. We detail how practical issues related to sampling and model misspecification may be addressed using semi-parametric techniques for time series, and we demonstrate the effectiveness of our stochastic models through application to both real-world data and to numerical model output.
no_new_dataset
0.949059
1602.06662
Mikael Henaff
Mikael Henaff, Arthur Szlam, Yann LeCun
Recurrent Orthogonal Networks and Long-Memory Tasks
null
null
null
null
cs.NE cs.AI cs.LG stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Although RNNs have been shown to be powerful tools for processing sequential data, finding architectures or optimization strategies that allow them to model very long term dependencies is still an active area of research. In this work, we carefully analyze two synthetic datasets originally outlined in (Hochreiter and Schmidhuber, 1997) which are used to evaluate the ability of RNNs to store information over many time steps. We explicitly construct RNN solutions to these problems, and using these constructions, illuminate both the problems themselves and the way in which RNNs store different types of information in their hidden states. These constructions furthermore explain the success of recent methods that specify unitary initializations or constraints on the transition matrices.
[ { "version": "v1", "created": "Mon, 22 Feb 2016 06:51:25 GMT" }, { "version": "v2", "created": "Wed, 15 Mar 2017 17:45:08 GMT" } ]
2017-03-16T00:00:00
[ [ "Henaff", "Mikael", "" ], [ "Szlam", "Arthur", "" ], [ "LeCun", "Yann", "" ] ]
TITLE: Recurrent Orthogonal Networks and Long-Memory Tasks ABSTRACT: Although RNNs have been shown to be powerful tools for processing sequential data, finding architectures or optimization strategies that allow them to model very long term dependencies is still an active area of research. In this work, we carefully analyze two synthetic datasets originally outlined in (Hochreiter and Schmidhuber, 1997) which are used to evaluate the ability of RNNs to store information over many time steps. We explicitly construct RNN solutions to these problems, and using these constructions, illuminate both the problems themselves and the way in which RNNs store different types of information in their hidden states. These constructions furthermore explain the success of recent methods that specify unitary initializations or constraints on the transition matrices.
no_new_dataset
0.94743
1610.02242
Samuli Laine
Samuli Laine, Timo Aila
Temporal Ensembling for Semi-Supervised Learning
Final ICLR 2017 version. Includes new results for CIFAR-100 with additional unlabeled data from Tiny Images dataset
null
null
null
cs.NE cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we present a simple and efficient method for training deep neural networks in a semi-supervised setting where only a small portion of training data is labeled. We introduce self-ensembling, where we form a consensus prediction of the unknown labels using the outputs of the network-in-training on different epochs, and most importantly, under different regularization and input augmentation conditions. This ensemble prediction can be expected to be a better predictor for the unknown labels than the output of the network at the most recent training epoch, and can thus be used as a target for training. Using our method, we set new records for two standard semi-supervised learning benchmarks, reducing the (non-augmented) classification error rate from 18.44% to 7.05% in SVHN with 500 labels and from 18.63% to 16.55% in CIFAR-10 with 4000 labels, and further to 5.12% and 12.16% by enabling the standard augmentations. We additionally obtain a clear improvement in CIFAR-100 classification accuracy by using random images from the Tiny Images dataset as unlabeled extra inputs during training. Finally, we demonstrate good tolerance to incorrect labels.
[ { "version": "v1", "created": "Fri, 7 Oct 2016 12:15:42 GMT" }, { "version": "v2", "created": "Mon, 7 Nov 2016 13:27:40 GMT" }, { "version": "v3", "created": "Wed, 15 Mar 2017 14:22:41 GMT" } ]
2017-03-16T00:00:00
[ [ "Laine", "Samuli", "" ], [ "Aila", "Timo", "" ] ]
TITLE: Temporal Ensembling for Semi-Supervised Learning ABSTRACT: In this paper, we present a simple and efficient method for training deep neural networks in a semi-supervised setting where only a small portion of training data is labeled. We introduce self-ensembling, where we form a consensus prediction of the unknown labels using the outputs of the network-in-training on different epochs, and most importantly, under different regularization and input augmentation conditions. This ensemble prediction can be expected to be a better predictor for the unknown labels than the output of the network at the most recent training epoch, and can thus be used as a target for training. Using our method, we set new records for two standard semi-supervised learning benchmarks, reducing the (non-augmented) classification error rate from 18.44% to 7.05% in SVHN with 500 labels and from 18.63% to 16.55% in CIFAR-10 with 4000 labels, and further to 5.12% and 12.16% by enabling the standard augmentations. We additionally obtain a clear improvement in CIFAR-100 classification accuracy by using random images from the Tiny Images dataset as unlabeled extra inputs during training. Finally, we demonstrate good tolerance to incorrect labels.
no_new_dataset
0.948155
1701.06454
Domagoj Vrgo\v{c}
Jorge Baier, Dietrich Daroch, Juan Reutter, Domagoj Vrgo\v{c}
Evaluating navigational RDF queries over the Web
null
null
null
null
cs.DB
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Semantic Web, and its underlying data format RDF, lend themselves naturally to navigational querying due to their graph-like structure. This is particularly evident when considering RDF data on the Web, where various separately published datasets reference each other and form a giant graph known as the Web of Linked Data. And while navigational queries over singular RDF datasets are supported through SPARQL property paths, not much is known about evaluating them over Linked Data. In this paper we propose a method for evaluating property path queries over the Web based on the classical AI search algorithm A*, show its optimality in the open world setting of the Web, and test it using real world queries which access a variety of RDF datasets available online.
[ { "version": "v1", "created": "Mon, 23 Jan 2017 15:31:17 GMT" }, { "version": "v2", "created": "Tue, 14 Mar 2017 20:24:41 GMT" } ]
2017-03-16T00:00:00
[ [ "Baier", "Jorge", "" ], [ "Daroch", "Dietrich", "" ], [ "Reutter", "Juan", "" ], [ "Vrgoč", "Domagoj", "" ] ]
TITLE: Evaluating navigational RDF queries over the Web ABSTRACT: Semantic Web, and its underlying data format RDF, lend themselves naturally to navigational querying due to their graph-like structure. This is particularly evident when considering RDF data on the Web, where various separately published datasets reference each other and form a giant graph known as the Web of Linked Data. And while navigational queries over singular RDF datasets are supported through SPARQL property paths, not much is known about evaluating them over Linked Data. In this paper we propose a method for evaluating property path queries over the Web based on the classical AI search algorithm A*, show its optimality in the open world setting of the Web, and test it using real world queries which access a variety of RDF datasets available online.
no_new_dataset
0.948537
1702.06740
Qiaolin Xia
Qiaolin Xia, Baobao Chang, Zhifang Sui
Improving Chinese SRL with Heterogeneous Annotations
This paper has been withdrawn by the author due to a crucial error in equation 10
null
null
null
cs.CL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Previous studies on Chinese semantic role labeling (SRL) have concentrated on single semantically annotated corpus. But the training data of single corpus is often limited. Meanwhile, there usually exists other semantically annotated corpora for Chinese SRL scattered across different annotation frameworks. Data sparsity remains a bottleneck. This situation calls for larger training datasets, or effective approaches which can take advantage of highly heterogeneous data. In these papers, we focus mainly on the latter, that is, to improve Chinese SRL by using heterogeneous corpora together. We propose a novel progressive learning model which augments the Progressive Neural Network with Gated Recurrent Adapters. The model can accommodate heterogeneous inputs and effectively transfer knowledge between them. We also release a new corpus, Chinese SemBank, for Chinese SRL. Experiments on CPB 1.0 show that ours model outperforms state-of-the-art methods.
[ { "version": "v1", "created": "Wed, 22 Feb 2017 10:34:47 GMT" }, { "version": "v2", "created": "Mon, 13 Mar 2017 06:46:12 GMT" }, { "version": "v3", "created": "Tue, 14 Mar 2017 13:05:23 GMT" } ]
2017-03-16T00:00:00
[ [ "Xia", "Qiaolin", "" ], [ "Chang", "Baobao", "" ], [ "Sui", "Zhifang", "" ] ]
TITLE: Improving Chinese SRL with Heterogeneous Annotations ABSTRACT: Previous studies on Chinese semantic role labeling (SRL) have concentrated on single semantically annotated corpus. But the training data of single corpus is often limited. Meanwhile, there usually exists other semantically annotated corpora for Chinese SRL scattered across different annotation frameworks. Data sparsity remains a bottleneck. This situation calls for larger training datasets, or effective approaches which can take advantage of highly heterogeneous data. In these papers, we focus mainly on the latter, that is, to improve Chinese SRL by using heterogeneous corpora together. We propose a novel progressive learning model which augments the Progressive Neural Network with Gated Recurrent Adapters. The model can accommodate heterogeneous inputs and effectively transfer knowledge between them. We also release a new corpus, Chinese SemBank, for Chinese SRL. Experiments on CPB 1.0 show that ours model outperforms state-of-the-art methods.
no_new_dataset
0.528651
1702.07021
Trang Pham
Trang Pham, Truyen Tran, Svetha Venkatesh
One Size Fits Many: Column Bundle for Multi-X Learning
null
null
null
null
stat.ML cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Much recent machine learning research has been directed towards leveraging shared statistics among labels, instances and data views, commonly referred to as multi-label, multi-instance and multi-view learning. The underlying premises are that there exist correlations among input parts and among output targets, and the predictive performance would increase when the correlations are incorporated. In this paper, we propose Column Bundle (CLB), a novel deep neural network for capturing the shared statistics in data. CLB is generic that the same architecture can be applied for various types of shared statistics by changing only input and output handling. CLB is capable of scaling to thousands of input parts and output labels by avoiding explicit modeling of pairwise relations. We evaluate CLB on different types of data: (a) multi-label, (b) multi-view, (c) multi-view/multi-label and (d) multi-instance. CLB demonstrates a comparable and competitive performance in all datasets against state-of-the-art methods designed specifically for each type.
[ { "version": "v1", "created": "Wed, 22 Feb 2017 21:54:12 GMT" }, { "version": "v2", "created": "Tue, 14 Mar 2017 00:44:14 GMT" } ]
2017-03-16T00:00:00
[ [ "Pham", "Trang", "" ], [ "Tran", "Truyen", "" ], [ "Venkatesh", "Svetha", "" ] ]
TITLE: One Size Fits Many: Column Bundle for Multi-X Learning ABSTRACT: Much recent machine learning research has been directed towards leveraging shared statistics among labels, instances and data views, commonly referred to as multi-label, multi-instance and multi-view learning. The underlying premises are that there exist correlations among input parts and among output targets, and the predictive performance would increase when the correlations are incorporated. In this paper, we propose Column Bundle (CLB), a novel deep neural network for capturing the shared statistics in data. CLB is generic that the same architecture can be applied for various types of shared statistics by changing only input and output handling. CLB is capable of scaling to thousands of input parts and output labels by avoiding explicit modeling of pairwise relations. We evaluate CLB on different types of data: (a) multi-label, (b) multi-view, (c) multi-view/multi-label and (d) multi-instance. CLB demonstrates a comparable and competitive performance in all datasets against state-of-the-art methods designed specifically for each type.
no_new_dataset
0.94887
1702.07025
Cristina Vasconcelos
Cristina Nader Vasconcelos, B\'arbara Nader Vasconcelos
Convolutional Neural Network Committees for Melanoma Classification with Classical And Expert Knowledge Based Image Transforms Data Augmentation
null
null
null
null
cs.CV
http://creativecommons.org/publicdomain/zero/1.0/
Skin cancer is a major public health problem, as is the most common type of cancer and represents more than half of cancer diagnoses worldwide. Early detection influences the outcome of the disease and motivates our work. We investigate the composition of CNN committees and data augmentation for the the ISBI 2017 Melanoma Classification Challenge (named Skin Lesion Analysis towards Melanoma Detection) facing the peculiarities of dealing with such a small, unbalanced, biological database. For that, we explore committees of Convolutional Neural Networks trained over the ISBI challenge training dataset artificially augmented by both classical image processing transforms and image warping guided by specialist knowledge about the lesion axis and improve the final classifier invariance to common melanoma variations.
[ { "version": "v1", "created": "Wed, 22 Feb 2017 22:17:13 GMT" }, { "version": "v2", "created": "Wed, 15 Mar 2017 11:50:58 GMT" } ]
2017-03-16T00:00:00
[ [ "Vasconcelos", "Cristina Nader", "" ], [ "Vasconcelos", "Bárbara Nader", "" ] ]
TITLE: Convolutional Neural Network Committees for Melanoma Classification with Classical And Expert Knowledge Based Image Transforms Data Augmentation ABSTRACT: Skin cancer is a major public health problem, as is the most common type of cancer and represents more than half of cancer diagnoses worldwide. Early detection influences the outcome of the disease and motivates our work. We investigate the composition of CNN committees and data augmentation for the the ISBI 2017 Melanoma Classification Challenge (named Skin Lesion Analysis towards Melanoma Detection) facing the peculiarities of dealing with such a small, unbalanced, biological database. For that, we explore committees of Convolutional Neural Networks trained over the ISBI challenge training dataset artificially augmented by both classical image processing transforms and image warping guided by specialist knowledge about the lesion axis and improve the final classifier invariance to common melanoma variations.
no_new_dataset
0.950457
1703.02180
Yunpeng Chen
Chen Yunpeng, Jin Xiaojie, Kang Bingyi, Feng Jiashi, Yan Shuicheng
Sharing Residual Units Through Collective Tensor Factorization in Deep Neural Networks
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Residual units are wildly used for alleviating optimization difficulties when building deep neural networks. However, the performance gain does not well compensate the model size increase, indicating low parameter efficiency in these residual units. In this work, we first revisit the residual function in several variations of residual units and demonstrate that these residual functions can actually be explained with a unified framework based on generalized block term decomposition. Then, based on the new explanation, we propose a new architecture, Collective Residual Unit (CRU), which enhances the parameter efficiency of deep neural networks through collective tensor factorization. CRU enables knowledge sharing across different residual units using shared factors. Experimental results show that our proposed CRU Network demonstrates outstanding parameter efficiency, achieving comparable classification performance to ResNet-200 with the model size of ResNet-50. By building a deeper network using CRU, we can achieve state-of-the-art single model classification accuracy on ImageNet-1k and Places365-Standard benchmark datasets. (Code and trained models are available on GitHub)
[ { "version": "v1", "created": "Tue, 7 Mar 2017 02:20:57 GMT" }, { "version": "v2", "created": "Wed, 15 Mar 2017 15:00:26 GMT" } ]
2017-03-16T00:00:00
[ [ "Yunpeng", "Chen", "" ], [ "Xiaojie", "Jin", "" ], [ "Bingyi", "Kang", "" ], [ "Jiashi", "Feng", "" ], [ "Shuicheng", "Yan", "" ] ]
TITLE: Sharing Residual Units Through Collective Tensor Factorization in Deep Neural Networks ABSTRACT: Residual units are wildly used for alleviating optimization difficulties when building deep neural networks. However, the performance gain does not well compensate the model size increase, indicating low parameter efficiency in these residual units. In this work, we first revisit the residual function in several variations of residual units and demonstrate that these residual functions can actually be explained with a unified framework based on generalized block term decomposition. Then, based on the new explanation, we propose a new architecture, Collective Residual Unit (CRU), which enhances the parameter efficiency of deep neural networks through collective tensor factorization. CRU enables knowledge sharing across different residual units using shared factors. Experimental results show that our proposed CRU Network demonstrates outstanding parameter efficiency, achieving comparable classification performance to ResNet-200 with the model size of ResNet-50. By building a deeper network using CRU, we can achieve state-of-the-art single model classification accuracy on ImageNet-1k and Places365-Standard benchmark datasets. (Code and trained models are available on GitHub)
no_new_dataset
0.947769
1703.03372
Dhanesh Ramachandram
Dhanesh Ramachandram and Terrance DeVries
LesionSeg: Semantic segmentation of skin lesions using Deep Convolutional Neural Network
null
null
null
null
cs.CV cs.AI cs.NE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a method for skin lesion segmentation for the ISIC 2017 Skin Lesion Segmentation Challenge. Our approach is based on a Fully Convolutional Network architecture which is trained end to end, from scratch, on a limited dataset. Our semantic segmentation architecture utilizes several recent innovations in particularly in the combined use of (i) use of atrous convolutions to increase the effective field of view of the network's receptive field without increasing the number of parameters, (ii) the use of network-in-network $1\times1$ convolution layers to add capacity to the network and (iii) state-of-art super-resolution upsampling of predictions using subpixel CNN layers. We reported a mean IOU score of 0.642 on the validation set provided by the organisers.
[ { "version": "v1", "created": "Thu, 9 Mar 2017 17:52:28 GMT" }, { "version": "v2", "created": "Fri, 10 Mar 2017 19:56:40 GMT" }, { "version": "v3", "created": "Wed, 15 Mar 2017 01:37:18 GMT" } ]
2017-03-16T00:00:00
[ [ "Ramachandram", "Dhanesh", "" ], [ "DeVries", "Terrance", "" ] ]
TITLE: LesionSeg: Semantic segmentation of skin lesions using Deep Convolutional Neural Network ABSTRACT: We present a method for skin lesion segmentation for the ISIC 2017 Skin Lesion Segmentation Challenge. Our approach is based on a Fully Convolutional Network architecture which is trained end to end, from scratch, on a limited dataset. Our semantic segmentation architecture utilizes several recent innovations in particularly in the combined use of (i) use of atrous convolutions to increase the effective field of view of the network's receptive field without increasing the number of parameters, (ii) the use of network-in-network $1\times1$ convolution layers to add capacity to the network and (iii) state-of-art super-resolution upsampling of predictions using subpixel CNN layers. We reported a mean IOU score of 0.642 on the validation set provided by the organisers.
no_new_dataset
0.951278
1703.03937
Xavier Alameda-Pineda
Xavier Alameda-Pineda and Andrea Pilzer and Dan Xu and Nicu Sebe and Elisa Ricci
Viraliency: Pooling Local Virality
Accepted at IEEE CVPR 2017
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In our overly-connected world, the automatic recognition of virality - the quality of an image or video to be rapidly and widely spread in social networks - is of crucial importance, and has recently awaken the interest of the computer vision community. Concurrently, recent progress in deep learning architectures showed that global pooling strategies allow the extraction of activation maps, which highlight the parts of the image most likely to contain instances of a certain class. We extend this concept by introducing a pooling layer that learns the size of the support area to be averaged: the learned top-N average (LENA) pooling. We hypothesize that the latent concepts (feature maps) describing virality may require such a rich pooling strategy. We assess the effectiveness of the LENA layer by appending it on top of a convolutional siamese architecture and evaluate its performance on the task of predicting and localizing virality. We report experiments on two publicly available datasets annotated for virality and show that our method outperforms state-of-the-art approaches.
[ { "version": "v1", "created": "Sat, 11 Mar 2017 10:01:11 GMT" }, { "version": "v2", "created": "Wed, 15 Mar 2017 07:36:58 GMT" } ]
2017-03-16T00:00:00
[ [ "Alameda-Pineda", "Xavier", "" ], [ "Pilzer", "Andrea", "" ], [ "Xu", "Dan", "" ], [ "Sebe", "Nicu", "" ], [ "Ricci", "Elisa", "" ] ]
TITLE: Viraliency: Pooling Local Virality ABSTRACT: In our overly-connected world, the automatic recognition of virality - the quality of an image or video to be rapidly and widely spread in social networks - is of crucial importance, and has recently awaken the interest of the computer vision community. Concurrently, recent progress in deep learning architectures showed that global pooling strategies allow the extraction of activation maps, which highlight the parts of the image most likely to contain instances of a certain class. We extend this concept by introducing a pooling layer that learns the size of the support area to be averaged: the learned top-N average (LENA) pooling. We hypothesize that the latent concepts (feature maps) describing virality may require such a rich pooling strategy. We assess the effectiveness of the LENA layer by appending it on top of a convolutional siamese architecture and evaluate its performance on the task of predicting and localizing virality. We report experiments on two publicly available datasets annotated for virality and show that our method outperforms state-of-the-art approaches.
no_new_dataset
0.946794
1703.04636
Giovanni Poggi
Luca D'Amiano, Davide Cozzolino, Giovanni Poggi, Luisa Verdoliva
A PatchMatch-based Dense-field Algorithm for Video Copy-Move Detection and Localization
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a new algorithm for the reliable detection and localization of video copy-move forgeries. Discovering well crafted video copy-moves may be very difficult, especially when some uniform background is copied to occlude foreground objects. To reliably detect both additive and occlusive copy-moves we use a dense-field approach, with invariant features that guarantee robustness to several post-processing operations. To limit complexity, a suitable video-oriented version of PatchMatch is used, with a multiresolution search strategy, and a focus on volumes of interest. Performance assessment relies on a new dataset, designed ad hoc, with realistic copy-moves and a wide variety of challenging situations. Experimental results show the proposed method to detect and localize video copy-moves with good accuracy even in adverse conditions.
[ { "version": "v1", "created": "Tue, 14 Mar 2017 18:08:49 GMT" } ]
2017-03-16T00:00:00
[ [ "D'Amiano", "Luca", "" ], [ "Cozzolino", "Davide", "" ], [ "Poggi", "Giovanni", "" ], [ "Verdoliva", "Luisa", "" ] ]
TITLE: A PatchMatch-based Dense-field Algorithm for Video Copy-Move Detection and Localization ABSTRACT: We propose a new algorithm for the reliable detection and localization of video copy-move forgeries. Discovering well crafted video copy-moves may be very difficult, especially when some uniform background is copied to occlude foreground objects. To reliably detect both additive and occlusive copy-moves we use a dense-field approach, with invariant features that guarantee robustness to several post-processing operations. To limit complexity, a suitable video-oriented version of PatchMatch is used, with a multiresolution search strategy, and a focus on volumes of interest. Performance assessment relies on a new dataset, designed ad hoc, with realistic copy-moves and a wide variety of challenging situations. Experimental results show the proposed method to detect and localize video copy-moves with good accuracy even in adverse conditions.
new_dataset
0.953057
1703.04664
Anshumali Shrivastava
Anshumali Shrivastava
Optimal Densification for Fast and Accurate Minwise Hashing
Fast Minwise Hashing
null
null
null
cs.DS cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Minwise hashing is a fundamental and one of the most successful hashing algorithm in the literature. Recent advances based on the idea of densification~\cite{Proc:OneHashLSH_ICML14,Proc:Shrivastava_UAI14} have shown that it is possible to compute $k$ minwise hashes, of a vector with $d$ nonzeros, in mere $(d + k)$ computations, a significant improvement over the classical $O(dk)$. These advances have led to an algorithmic improvement in the query complexity of traditional indexing algorithms based on minwise hashing. Unfortunately, the variance of the current densification techniques is unnecessarily high, which leads to significantly poor accuracy compared to vanilla minwise hashing, especially when the data is sparse. In this paper, we provide a novel densification scheme which relies on carefully tailored 2-universal hashes. We show that the proposed scheme is variance-optimal, and without losing the runtime efficiency, it is significantly more accurate than existing densification techniques. As a result, we obtain a significantly efficient hashing scheme which has the same variance and collision probability as minwise hashing. Experimental evaluations on real sparse and high-dimensional datasets validate our claims. We believe that given the significant advantages, our method will replace minwise hashing implementations in practice.
[ { "version": "v1", "created": "Tue, 14 Mar 2017 18:49:57 GMT" } ]
2017-03-16T00:00:00
[ [ "Shrivastava", "Anshumali", "" ] ]
TITLE: Optimal Densification for Fast and Accurate Minwise Hashing ABSTRACT: Minwise hashing is a fundamental and one of the most successful hashing algorithm in the literature. Recent advances based on the idea of densification~\cite{Proc:OneHashLSH_ICML14,Proc:Shrivastava_UAI14} have shown that it is possible to compute $k$ minwise hashes, of a vector with $d$ nonzeros, in mere $(d + k)$ computations, a significant improvement over the classical $O(dk)$. These advances have led to an algorithmic improvement in the query complexity of traditional indexing algorithms based on minwise hashing. Unfortunately, the variance of the current densification techniques is unnecessarily high, which leads to significantly poor accuracy compared to vanilla minwise hashing, especially when the data is sparse. In this paper, we provide a novel densification scheme which relies on carefully tailored 2-universal hashes. We show that the proposed scheme is variance-optimal, and without losing the runtime efficiency, it is significantly more accurate than existing densification techniques. As a result, we obtain a significantly efficient hashing scheme which has the same variance and collision probability as minwise hashing. Experimental evaluations on real sparse and high-dimensional datasets validate our claims. We believe that given the significant advantages, our method will replace minwise hashing implementations in practice.
no_new_dataset
0.9434
1703.04665
Alexander Broad S
Alexander Broad and Brenna Argall
Geometry-Based Region Proposals for Real-Time Robot Detection of Tabletop Objects
Update based on work presented at RSS 2016 Deep Learning Workshop
null
null
null
cs.RO cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a novel object detection pipeline for localization and recognition in three dimensional environments. Our approach makes use of an RGB-D sensor and combines state-of-the-art techniques from the robotics and computer vision communities to create a robust, real-time detection system. We focus specifically on solving the object detection problem for tabletop scenes, a common environment for assistive manipulators. Our detection pipeline locates objects in a point cloud representation of the scene. These clusters are subsequently used to compute a bounding box around each object in the RGB space. Each defined patch is then fed into a Convolutional Neural Network (CNN) for object recognition. We also demonstrate that our region proposal method can be used to develop novel datasets that are both large and diverse enough to train deep learning models, and easy enough to collect that end-users can develop their own datasets. Lastly, we validate the resulting system through an extensive analysis of the accuracy and run-time of the full pipeline.
[ { "version": "v1", "created": "Tue, 14 Mar 2017 18:51:18 GMT" } ]
2017-03-16T00:00:00
[ [ "Broad", "Alexander", "" ], [ "Argall", "Brenna", "" ] ]
TITLE: Geometry-Based Region Proposals for Real-Time Robot Detection of Tabletop Objects ABSTRACT: We present a novel object detection pipeline for localization and recognition in three dimensional environments. Our approach makes use of an RGB-D sensor and combines state-of-the-art techniques from the robotics and computer vision communities to create a robust, real-time detection system. We focus specifically on solving the object detection problem for tabletop scenes, a common environment for assistive manipulators. Our detection pipeline locates objects in a point cloud representation of the scene. These clusters are subsequently used to compute a bounding box around each object in the RGB space. Each defined patch is then fed into a Convolutional Neural Network (CNN) for object recognition. We also demonstrate that our region proposal method can be used to develop novel datasets that are both large and diverse enough to train deep learning models, and easy enough to collect that end-users can develop their own datasets. Lastly, we validate the resulting system through an extensive analysis of the accuracy and run-time of the full pipeline.
no_new_dataset
0.776114
1703.04670
Georgios Pavlakos
Georgios Pavlakos, Xiaowei Zhou, Aaron Chan, Konstantinos G. Derpanis, Kostas Daniilidis
6-DoF Object Pose from Semantic Keypoints
IEEE International Conference on Robotics and Automation (ICRA), 2017
null
null
null
cs.CV cs.RO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper presents a novel approach to estimating the continuous six degree of freedom (6-DoF) pose (3D translation and rotation) of an object from a single RGB image. The approach combines semantic keypoints predicted by a convolutional network (convnet) with a deformable shape model. Unlike prior work, we are agnostic to whether the object is textured or textureless, as the convnet learns the optimal representation from the available training image data. Furthermore, the approach can be applied to instance- and class-based pose recovery. Empirically, we show that the proposed approach can accurately recover the 6-DoF object pose for both instance- and class-based scenarios with a cluttered background. For class-based object pose estimation, state-of-the-art accuracy is shown on the large-scale PASCAL3D+ dataset.
[ { "version": "v1", "created": "Tue, 14 Mar 2017 18:58:46 GMT" } ]
2017-03-16T00:00:00
[ [ "Pavlakos", "Georgios", "" ], [ "Zhou", "Xiaowei", "" ], [ "Chan", "Aaron", "" ], [ "Derpanis", "Konstantinos G.", "" ], [ "Daniilidis", "Kostas", "" ] ]
TITLE: 6-DoF Object Pose from Semantic Keypoints ABSTRACT: This paper presents a novel approach to estimating the continuous six degree of freedom (6-DoF) pose (3D translation and rotation) of an object from a single RGB image. The approach combines semantic keypoints predicted by a convolutional network (convnet) with a deformable shape model. Unlike prior work, we are agnostic to whether the object is textured or textureless, as the convnet learns the optimal representation from the available training image data. Furthermore, the approach can be applied to instance- and class-based pose recovery. Empirically, we show that the proposed approach can accurately recover the 6-DoF object pose for both instance- and class-based scenarios with a cluttered background. For class-based object pose estimation, state-of-the-art accuracy is shown on the large-scale PASCAL3D+ dataset.
no_new_dataset
0.947575
1703.04697
Evgenii Chzhen
Evgenii Chzhen, Christophe Denis, Mohamed Hebiri, Joseph Salmon
On the benefits of output sparsity for multi-label classification
null
null
null
null
math.ST cs.LG stat.ML stat.TH
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The multi-label classification framework, where each observation can be associated with a set of labels, has generated a tremendous amount of attention over recent years. The modern multi-label problems are typically large-scale in terms of number of observations, features and labels, and the amount of labels can even be comparable with the amount of observations. In this context, different remedies have been proposed to overcome the curse of dimensionality. In this work, we aim at exploiting the output sparsity by introducing a new loss, called the sparse weighted Hamming loss. This proposed loss can be seen as a weighted version of classical ones, where active and inactive labels are weighted separately. Leveraging the influence of sparsity in the loss function, we provide improved generalization bounds for the empirical risk minimizer, a suitable property for large-scale problems. For this new loss, we derive rates of convergence linear in the underlying output-sparsity rather than linear in the number of labels. In practice, minimizing the associated risk can be performed efficiently by using convex surrogates and modern convex optimization algorithms. We provide experiments on various real-world datasets demonstrating the pertinence of our approach when compared to non-weighted techniques.
[ { "version": "v1", "created": "Tue, 14 Mar 2017 20:19:08 GMT" } ]
2017-03-16T00:00:00
[ [ "Chzhen", "Evgenii", "" ], [ "Denis", "Christophe", "" ], [ "Hebiri", "Mohamed", "" ], [ "Salmon", "Joseph", "" ] ]
TITLE: On the benefits of output sparsity for multi-label classification ABSTRACT: The multi-label classification framework, where each observation can be associated with a set of labels, has generated a tremendous amount of attention over recent years. The modern multi-label problems are typically large-scale in terms of number of observations, features and labels, and the amount of labels can even be comparable with the amount of observations. In this context, different remedies have been proposed to overcome the curse of dimensionality. In this work, we aim at exploiting the output sparsity by introducing a new loss, called the sparse weighted Hamming loss. This proposed loss can be seen as a weighted version of classical ones, where active and inactive labels are weighted separately. Leveraging the influence of sparsity in the loss function, we provide improved generalization bounds for the empirical risk minimizer, a suitable property for large-scale problems. For this new loss, we derive rates of convergence linear in the underlying output-sparsity rather than linear in the number of labels. In practice, minimizing the associated risk can be performed efficiently by using convex surrogates and modern convex optimization algorithms. We provide experiments on various real-world datasets demonstrating the pertinence of our approach when compared to non-weighted techniques.
no_new_dataset
0.943608
1703.04819
Sandra Avila
Afonso Menegola, Julia Tavares, Michel Fornaciali, Lin Tzy Li, Sandra Avila, Eduardo Valle
RECOD Titans at ISIC Challenge 2017
5 pages
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This extended abstract describes the participation of RECOD Titans in parts 1 and 3 of the ISIC Challenge 2017 "Skin Lesion Analysis Towards Melanoma Detection" (ISBI 2017). Although our team has a long experience with melanoma classification, the ISIC Challenge 2017 was the very first time we worked on skin-lesion segmentation. For part 1 (segmentation), our final submission used four of our models: two trained with all 2000 samples, without a validation split, for 250 and for 500 epochs respectively; and other two trained and validated with two different 1600/400 splits, for 220 epochs. Those four models, individually, achieved between 0.780 and 0.783 official validation scores. Our final submission averaged the output of those four models achieved a score of 0.793. For part 3 (classification), the submitted test run as well as our last official validation run were the result from a meta-model that assembled seven base deep-learning models: three based on Inception-V4 trained on our largest dataset; three based on Inception trained on our smallest dataset; and one based on ResNet-101 trained on our smaller dataset. The results of those component models were stacked in a meta-learning layer based on an SVM trained on the validation set of our largest dataset.
[ { "version": "v1", "created": "Tue, 14 Mar 2017 23:11:04 GMT" } ]
2017-03-16T00:00:00
[ [ "Menegola", "Afonso", "" ], [ "Tavares", "Julia", "" ], [ "Fornaciali", "Michel", "" ], [ "Li", "Lin Tzy", "" ], [ "Avila", "Sandra", "" ], [ "Valle", "Eduardo", "" ] ]
TITLE: RECOD Titans at ISIC Challenge 2017 ABSTRACT: This extended abstract describes the participation of RECOD Titans in parts 1 and 3 of the ISIC Challenge 2017 "Skin Lesion Analysis Towards Melanoma Detection" (ISBI 2017). Although our team has a long experience with melanoma classification, the ISIC Challenge 2017 was the very first time we worked on skin-lesion segmentation. For part 1 (segmentation), our final submission used four of our models: two trained with all 2000 samples, without a validation split, for 250 and for 500 epochs respectively; and other two trained and validated with two different 1600/400 splits, for 220 epochs. Those four models, individually, achieved between 0.780 and 0.783 official validation scores. Our final submission averaged the output of those four models achieved a score of 0.793. For part 3 (classification), the submitted test run as well as our last official validation run were the result from a meta-model that assembled seven base deep-learning models: three based on Inception-V4 trained on our largest dataset; three based on Inception trained on our smallest dataset; and one based on ResNet-101 trained on our smaller dataset. The results of those component models were stacked in a meta-learning layer based on an SVM trained on the validation set of our largest dataset.
no_new_dataset
0.942876
1703.04824
Jan Haji\v{c} Jr
Jan Haji\v{c} jr., Pavel Pecina
In Search of a Dataset for Handwritten Optical Music Recognition: Introducing MUSCIMA++
null
null
null
null
cs.CV
http://creativecommons.org/licenses/by-sa/4.0/
Optical Music Recognition (OMR) has long been without an adequate dataset and ground truth for evaluating OMR systems, which has been a major problem for establishing a state of the art in the field. Furthermore, machine learning methods require training data. We analyze how the OMR processing pipeline can be expressed in terms of gradually more complex ground truth, and based on this analysis, we design the MUSCIMA++ dataset of handwritten music notation that addresses musical symbol recognition and notation reconstruction. The MUSCIMA++ dataset version 0.9 consists of 140 pages of handwritten music, with 91255 manually annotated notation symbols and 82261 explicitly marked relationships between symbol pairs. The dataset allows training and evaluating models for symbol classification, symbol localization, and notation graph assembly, both in isolation and jointly. Open-source tools are provided for manipulating the dataset, visualizing the data and further annotation, and the dataset itself is made available under an open license.
[ { "version": "v1", "created": "Tue, 14 Mar 2017 23:21:26 GMT" } ]
2017-03-16T00:00:00
[ [ "Hajič", "Jan", "jr." ], [ "Pecina", "Pavel", "" ] ]
TITLE: In Search of a Dataset for Handwritten Optical Music Recognition: Introducing MUSCIMA++ ABSTRACT: Optical Music Recognition (OMR) has long been without an adequate dataset and ground truth for evaluating OMR systems, which has been a major problem for establishing a state of the art in the field. Furthermore, machine learning methods require training data. We analyze how the OMR processing pipeline can be expressed in terms of gradually more complex ground truth, and based on this analysis, we design the MUSCIMA++ dataset of handwritten music notation that addresses musical symbol recognition and notation reconstruction. The MUSCIMA++ dataset version 0.9 consists of 140 pages of handwritten music, with 91255 manually annotated notation symbols and 82261 explicitly marked relationships between symbol pairs. The dataset allows training and evaluating models for symbol classification, symbol localization, and notation graph assembly, both in isolation and jointly. Open-source tools are provided for manipulating the dataset, visualizing the data and further annotation, and the dataset itself is made available under an open license.
new_dataset
0.965348
1703.04835
Wei-An Lin
Wei-An Lin and Jun-Cheng Chen and Rama Chellappa
A Proximity-Aware Hierarchical Clustering of Faces
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we propose an unsupervised face clustering algorithm called "Proximity-Aware Hierarchical Clustering" (PAHC) that exploits the local structure of deep representations. In the proposed method, a similarity measure between deep features is computed by evaluating linear SVM margins. SVMs are trained using nearest neighbors of sample data, and thus do not require any external training data. Clusters are then formed by thresholding the similarity scores. We evaluate the clustering performance using three challenging unconstrained face datasets, including Celebrity in Frontal-Profile (CFP), IARPA JANUS Benchmark A (IJB-A), and JANUS Challenge Set 3 (JANUS CS3) datasets. Experimental results demonstrate that the proposed approach can achieve significant improvements over state-of-the-art methods. Moreover, we also show that the proposed clustering algorithm can be applied to curate a set of large-scale and noisy training dataset while maintaining sufficient amount of images and their variations due to nuisance factors. The face verification performance on JANUS CS3 improves significantly by finetuning a DCNN model with the curated MS-Celeb-1M dataset which contains over three million face images.
[ { "version": "v1", "created": "Tue, 14 Mar 2017 23:41:45 GMT" } ]
2017-03-16T00:00:00
[ [ "Lin", "Wei-An", "" ], [ "Chen", "Jun-Cheng", "" ], [ "Chellappa", "Rama", "" ] ]
TITLE: A Proximity-Aware Hierarchical Clustering of Faces ABSTRACT: In this paper, we propose an unsupervised face clustering algorithm called "Proximity-Aware Hierarchical Clustering" (PAHC) that exploits the local structure of deep representations. In the proposed method, a similarity measure between deep features is computed by evaluating linear SVM margins. SVMs are trained using nearest neighbors of sample data, and thus do not require any external training data. Clusters are then formed by thresholding the similarity scores. We evaluate the clustering performance using three challenging unconstrained face datasets, including Celebrity in Frontal-Profile (CFP), IARPA JANUS Benchmark A (IJB-A), and JANUS Challenge Set 3 (JANUS CS3) datasets. Experimental results demonstrate that the proposed approach can achieve significant improvements over state-of-the-art methods. Moreover, we also show that the proposed clustering algorithm can be applied to curate a set of large-scale and noisy training dataset while maintaining sufficient amount of images and their variations due to nuisance factors. The face verification performance on JANUS CS3 improves significantly by finetuning a DCNN model with the curated MS-Celeb-1M dataset which contains over three million face images.
no_new_dataset
0.92111
1703.04853
Homa Foroughi
Homa Foroughi, Moein Shakeri, Nilanjan Ray, Hong Zhang
Face Recognition using Multi-Modal Low-Rank Dictionary Learning
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Face recognition has been widely studied due to its importance in different applications; however, most of the proposed methods fail when face images are occluded or captured under illumination and pose variations. Recently several low-rank dictionary learning methods have been proposed and achieved promising results for noisy observations. While these methods are mostly developed for single-modality scenarios, recent studies demonstrated the advantages of feature fusion from multiple inputs. We propose a multi-modal structured low-rank dictionary learning method for robust face recognition, using raw pixels of face images and their illumination invariant representation. The proposed method learns robust and discriminative representations from contaminated face images, even if there are few training samples with large intra-class variations. Extensive experiments on different datasets validate the superior performance and robustness of our method to severe illumination variations and occlusion.
[ { "version": "v1", "created": "Wed, 15 Mar 2017 00:38:01 GMT" } ]
2017-03-16T00:00:00
[ [ "Foroughi", "Homa", "" ], [ "Shakeri", "Moein", "" ], [ "Ray", "Nilanjan", "" ], [ "Zhang", "Hong", "" ] ]
TITLE: Face Recognition using Multi-Modal Low-Rank Dictionary Learning ABSTRACT: Face recognition has been widely studied due to its importance in different applications; however, most of the proposed methods fail when face images are occluded or captured under illumination and pose variations. Recently several low-rank dictionary learning methods have been proposed and achieved promising results for noisy observations. While these methods are mostly developed for single-modality scenarios, recent studies demonstrated the advantages of feature fusion from multiple inputs. We propose a multi-modal structured low-rank dictionary learning method for robust face recognition, using raw pixels of face images and their illumination invariant representation. The proposed method learns robust and discriminative representations from contaminated face images, even if there are few training samples with large intra-class variations. Extensive experiments on different datasets validate the superior performance and robustness of our method to severe illumination variations and occlusion.
no_new_dataset
0.947478
1703.04873
Wei-Han Lee
Wei-Han Lee, Changchang Liu, Shouling Ji, Prateek Mittal, Ruby Lee
Quantification of De-anonymization Risks in Social Networks
Published in International Conference on Information Systems Security and Privacy, 2017
null
null
null
cs.SI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The risks of publishing privacy-sensitive data have received considerable attention recently. Several de-anonymization attacks have been proposed to re-identify individuals even if data anonymization techniques were applied. However, there is no theoretical quantification for relating the data utility that is preserved by the anonymization techniques and the data vulnerability against de-anonymization attacks. In this paper, we theoretically analyze the de-anonymization attacks and provide conditions on the utility of the anonymized data (denoted by anonymized utility) to achieve successful de-anonymization. To the best of our knowledge, this is the first work on quantifying the relationships between anonymized utility and de-anonymization capability. Unlike previous work, our quantification analysis requires no assumptions about the graph model, thus providing a general theoretical guide for developing practical de-anonymization/anonymization techniques. Furthermore, we evaluate state-of-the-art de-anonymization attacks on a real-world Facebook dataset to show the limitations of previous work. By comparing these experimental results and the theoretically achievable de-anonymization capability derived in our analysis, we further demonstrate the ineffectiveness of previous de-anonymization attacks and the potential of more powerful de-anonymization attacks in the future.
[ { "version": "v1", "created": "Wed, 15 Mar 2017 01:35:48 GMT" } ]
2017-03-16T00:00:00
[ [ "Lee", "Wei-Han", "" ], [ "Liu", "Changchang", "" ], [ "Ji", "Shouling", "" ], [ "Mittal", "Prateek", "" ], [ "Lee", "Ruby", "" ] ]
TITLE: Quantification of De-anonymization Risks in Social Networks ABSTRACT: The risks of publishing privacy-sensitive data have received considerable attention recently. Several de-anonymization attacks have been proposed to re-identify individuals even if data anonymization techniques were applied. However, there is no theoretical quantification for relating the data utility that is preserved by the anonymization techniques and the data vulnerability against de-anonymization attacks. In this paper, we theoretically analyze the de-anonymization attacks and provide conditions on the utility of the anonymized data (denoted by anonymized utility) to achieve successful de-anonymization. To the best of our knowledge, this is the first work on quantifying the relationships between anonymized utility and de-anonymization capability. Unlike previous work, our quantification analysis requires no assumptions about the graph model, thus providing a general theoretical guide for developing practical de-anonymization/anonymization techniques. Furthermore, we evaluate state-of-the-art de-anonymization attacks on a real-world Facebook dataset to show the limitations of previous work. By comparing these experimental results and the theoretically achievable de-anonymization capability derived in our analysis, we further demonstrate the ineffectiveness of previous de-anonymization attacks and the potential of more powerful de-anonymization attacks in the future.
no_new_dataset
0.946051
1703.04967
Holger Roth
Mohammad Eshghi, Holger R. Roth, Masahiro Oda, Min Suk Chung, Kensaku Mori
Comparison of the Deep-Learning-Based Automated Segmentation Methods for the Head Sectioned Images of the Virtual Korean Human Project
Accepted for presentation at the 15th IAPR Conference on Machine Vision Applications (MVA2017), Nagoya, Japan
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper presents an end-to-end pixelwise fully automated segmentation of the head sectioned images of the Visible Korean Human (VKH) project based on Deep Convolutional Neural Networks (DCNNs). By converting classification networks into Fully Convolutional Networks (FCNs), a coarse prediction map, with smaller size than the original input image, can be created for segmentation purposes. To refine this map and to obtain a dense pixel-wise output, standard FCNs use deconvolution layers to upsample the coarse map. However, upsampling based on deconvolution increases the number of network parameters and causes loss of detail because of interpolation. On the other hand, dilated convolution is a new technique introduced recently that attempts to capture multi-scale contextual information without increasing the network parameters while keeping the resolution of the prediction maps high. We used both a standard FCN and a dilated convolution based FCN for semantic segmentation of the head sectioned images of the VKH dataset. Quantitative results showed approximately 20% improvement in the segmentation accuracy when using FCNs with dilated convolutions.
[ { "version": "v1", "created": "Wed, 15 Mar 2017 06:49:01 GMT" } ]
2017-03-16T00:00:00
[ [ "Eshghi", "Mohammad", "" ], [ "Roth", "Holger R.", "" ], [ "Oda", "Masahiro", "" ], [ "Chung", "Min Suk", "" ], [ "Mori", "Kensaku", "" ] ]
TITLE: Comparison of the Deep-Learning-Based Automated Segmentation Methods for the Head Sectioned Images of the Virtual Korean Human Project ABSTRACT: This paper presents an end-to-end pixelwise fully automated segmentation of the head sectioned images of the Visible Korean Human (VKH) project based on Deep Convolutional Neural Networks (DCNNs). By converting classification networks into Fully Convolutional Networks (FCNs), a coarse prediction map, with smaller size than the original input image, can be created for segmentation purposes. To refine this map and to obtain a dense pixel-wise output, standard FCNs use deconvolution layers to upsample the coarse map. However, upsampling based on deconvolution increases the number of network parameters and causes loss of detail because of interpolation. On the other hand, dilated convolution is a new technique introduced recently that attempts to capture multi-scale contextual information without increasing the network parameters while keeping the resolution of the prediction maps high. We used both a standard FCN and a dilated convolution based FCN for semantic segmentation of the head sectioned images of the VKH dataset. Quantitative results showed approximately 20% improvement in the segmentation accuracy when using FCNs with dilated convolutions.
no_new_dataset
0.94887
1703.04980
Veronika Cheplygina
Veronika Cheplygina and Lauge S{\o}rensen and David M. J. Tax and Jesper Holst Pedersen and Marco Loog and Marleen de Bruijne
Classification of COPD with Multiple Instance Learning
Published at International Conference on Pattern Recognition (ICPR) 2014
null
10.1109/ICPR.2014.268
null
cs.CV stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Chronic obstructive pulmonary disease (COPD) is a lung disease where early detection benefits the survival rate. COPD can be quantified by classifying patches of computed tomography images, and combining patch labels into an overall diagnosis for the image. As labeled patches are often not available, image labels are propagated to the patches, incorrectly labeling healthy patches in COPD patients as being affected by the disease. We approach quantification of COPD from lung images as a multiple instance learning (MIL) problem, which is more suitable for such weakly labeled data. We investigate various MIL assumptions in the context of COPD and show that although a concept region with COPD-related disease patterns is present, considering the whole distribution of lung tissue patches improves the performance. The best method is based on averaging instances and obtains an AUC of 0.742, which is higher than the previously reported best of 0.713 on the same dataset. Using the full training set further increases performance to 0.776, which is significantly higher (DeLong test) than previous results.
[ { "version": "v1", "created": "Wed, 15 Mar 2017 07:41:49 GMT" } ]
2017-03-16T00:00:00
[ [ "Cheplygina", "Veronika", "" ], [ "Sørensen", "Lauge", "" ], [ "Tax", "David M. J.", "" ], [ "Pedersen", "Jesper Holst", "" ], [ "Loog", "Marco", "" ], [ "de Bruijne", "Marleen", "" ] ]
TITLE: Classification of COPD with Multiple Instance Learning ABSTRACT: Chronic obstructive pulmonary disease (COPD) is a lung disease where early detection benefits the survival rate. COPD can be quantified by classifying patches of computed tomography images, and combining patch labels into an overall diagnosis for the image. As labeled patches are often not available, image labels are propagated to the patches, incorrectly labeling healthy patches in COPD patients as being affected by the disease. We approach quantification of COPD from lung images as a multiple instance learning (MIL) problem, which is more suitable for such weakly labeled data. We investigate various MIL assumptions in the context of COPD and show that although a concept region with COPD-related disease patterns is present, considering the whole distribution of lung tissue patches improves the performance. The best method is based on averaging instances and obtains an AUC of 0.742, which is higher than the previously reported best of 0.713 on the same dataset. Using the full training set further increases performance to 0.776, which is significantly higher (DeLong test) than previous results.
no_new_dataset
0.95253
1703.04981
Veronika Cheplygina
Veronika Cheplygina and Annegreet van Opbroek and M. Arfan Ikram and Meike W. Vernooij and Marleen de Bruijne
Transfer Learning by Asymmetric Image Weighting for Segmentation across Scanners
null
null
null
null
cs.CV stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Supervised learning has been very successful for automatic segmentation of images from a single scanner. However, several papers report deteriorated performances when using classifiers trained on images from one scanner to segment images from other scanners. We propose a transfer learning classifier that adapts to differences between training and test images. This method uses a weighted ensemble of classifiers trained on individual images. The weight of each classifier is determined by the similarity between its training image and the test image. We examine three unsupervised similarity measures, which can be used in scenarios where no labeled data from a newly introduced scanner or scanning protocol is available. The measures are based on a divergence, a bag distance, and on estimating the labels with a clustering procedure. These measures are asymmetric. We study whether the asymmetry can improve classification. Out of the three similarity measures, the bag similarity measure is the most robust across different studies and achieves excellent results on four brain tissue segmentation datasets and three white matter lesion segmentation datasets, acquired at different centers and with different scanners and scanning protocols. We show that the asymmetry can indeed be informative, and that computing the similarity from the test image to the training images is more appropriate than the opposite direction.
[ { "version": "v1", "created": "Wed, 15 Mar 2017 07:43:10 GMT" } ]
2017-03-16T00:00:00
[ [ "Cheplygina", "Veronika", "" ], [ "van Opbroek", "Annegreet", "" ], [ "Ikram", "M. Arfan", "" ], [ "Vernooij", "Meike W.", "" ], [ "de Bruijne", "Marleen", "" ] ]
TITLE: Transfer Learning by Asymmetric Image Weighting for Segmentation across Scanners ABSTRACT: Supervised learning has been very successful for automatic segmentation of images from a single scanner. However, several papers report deteriorated performances when using classifiers trained on images from one scanner to segment images from other scanners. We propose a transfer learning classifier that adapts to differences between training and test images. This method uses a weighted ensemble of classifiers trained on individual images. The weight of each classifier is determined by the similarity between its training image and the test image. We examine three unsupervised similarity measures, which can be used in scenarios where no labeled data from a newly introduced scanner or scanning protocol is available. The measures are based on a divergence, a bag distance, and on estimating the labels with a clustering procedure. These measures are asymmetric. We study whether the asymmetry can improve classification. Out of the three similarity measures, the bag similarity measure is the most robust across different studies and achieves excellent results on four brain tissue segmentation datasets and three white matter lesion segmentation datasets, acquired at different centers and with different scanners and scanning protocols. We show that the asymmetry can indeed be informative, and that computing the similarity from the test image to the training images is more appropriate than the opposite direction.
no_new_dataset
0.949669