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1606.02492
Shreyas Saxena
Shreyas Saxena and Jakob Verbeek
Convolutional Neural Fabrics
Corrected typos (In proceedings of NIPS16 )
null
null
null
cs.CV cs.LG cs.NE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Despite the success of CNNs, selecting the optimal architecture for a given task remains an open problem. Instead of aiming to select a single optimal architecture, we propose a "fabric" that embeds an exponentially large number of architectures. The fabric consists of a 3D trellis that connects response maps at different layers, scales, and channels with a sparse homogeneous local connectivity pattern. The only hyper-parameters of a fabric are the number of channels and layers. While individual architectures can be recovered as paths, the fabric can in addition ensemble all embedded architectures together, sharing their weights where their paths overlap. Parameters can be learned using standard methods based on back-propagation, at a cost that scales linearly in the fabric size. We present benchmark results competitive with the state of the art for image classification on MNIST and CIFAR10, and for semantic segmentation on the Part Labels dataset.
[ { "version": "v1", "created": "Wed, 8 Jun 2016 10:17:51 GMT" }, { "version": "v2", "created": "Thu, 9 Jun 2016 16:21:57 GMT" }, { "version": "v3", "created": "Fri, 28 Oct 2016 13:10:05 GMT" }, { "version": "v4", "created": "Mon, 30 Jan 2017 12:28:29 GMT" } ]
2017-01-31T00:00:00
[ [ "Saxena", "Shreyas", "" ], [ "Verbeek", "Jakob", "" ] ]
TITLE: Convolutional Neural Fabrics ABSTRACT: Despite the success of CNNs, selecting the optimal architecture for a given task remains an open problem. Instead of aiming to select a single optimal architecture, we propose a "fabric" that embeds an exponentially large number of architectures. The fabric consists of a 3D trellis that connects response maps at different layers, scales, and channels with a sparse homogeneous local connectivity pattern. The only hyper-parameters of a fabric are the number of channels and layers. While individual architectures can be recovered as paths, the fabric can in addition ensemble all embedded architectures together, sharing their weights where their paths overlap. Parameters can be learned using standard methods based on back-propagation, at a cost that scales linearly in the fabric size. We present benchmark results competitive with the state of the art for image classification on MNIST and CIFAR10, and for semantic segmentation on the Part Labels dataset.
no_new_dataset
0.946349
1607.04673
Abhineet Singh
Abhineet Singh, Mennatullah Siam and Martin Jagersand
Unifying Registration based Tracking: A Case Study with Structural Similarity
Accepted at WACV 2017. Supplementary available at: http://webdocs.cs.ualberta.ca/~vis/mtf/ssim_supplementary.pdf arXiv admin note: text overlap with arXiv:1603.01292
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper adapts a popular image quality measure called structural similarity for high precision registration based tracking while also introducing a simpler and faster variant of the same. Further, these are evaluated comprehensively against existing measures using a unified approach to study registration based trackers that decomposes them into three constituent sub modules - appearance model, state space model and search method. Several popular trackers in literature are broken down using this method so that their contributions - as of this paper - are shown to be limited to only one or two of these submodules. An open source tracking framework is made available that follows this decomposition closely through extensive use of generic programming. It is used to perform all experiments on four publicly available datasets so the results are easily reproducible. This framework provides a convenient interface to plug in a new method for any sub module and combine it with existing methods for the other two. It can also serve as a fast and flexible solution for practical tracking needs due to its highly efficient implementation.
[ { "version": "v1", "created": "Fri, 15 Jul 2016 22:25:46 GMT" }, { "version": "v2", "created": "Fri, 7 Oct 2016 08:19:18 GMT" }, { "version": "v3", "created": "Mon, 17 Oct 2016 04:52:14 GMT" }, { "version": "v4", "created": "Mon, 30 Jan 2017 14:50:49 GMT" } ]
2017-01-31T00:00:00
[ [ "Singh", "Abhineet", "" ], [ "Siam", "Mennatullah", "" ], [ "Jagersand", "Martin", "" ] ]
TITLE: Unifying Registration based Tracking: A Case Study with Structural Similarity ABSTRACT: This paper adapts a popular image quality measure called structural similarity for high precision registration based tracking while also introducing a simpler and faster variant of the same. Further, these are evaluated comprehensively against existing measures using a unified approach to study registration based trackers that decomposes them into three constituent sub modules - appearance model, state space model and search method. Several popular trackers in literature are broken down using this method so that their contributions - as of this paper - are shown to be limited to only one or two of these submodules. An open source tracking framework is made available that follows this decomposition closely through extensive use of generic programming. It is used to perform all experiments on four publicly available datasets so the results are easily reproducible. This framework provides a convenient interface to plug in a new method for any sub module and combine it with existing methods for the other two. It can also serve as a fast and flexible solution for practical tracking needs due to its highly efficient implementation.
no_new_dataset
0.939692
1610.05861
Samarth Manoj Brahmbhatt
Samarth Brahmbhatt, Henrik I. Christensen and James Hays
StuffNet: Using 'Stuff' to Improve Object Detection
Camera-ready version for IEEE WACV 2017
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a Convolutional Neural Network (CNN) based algorithm - StuffNet - for object detection. In addition to the standard convolutional features trained for region proposal and object detection [31], StuffNet uses convolutional features trained for segmentation of objects and 'stuff' (amorphous categories such as ground and water). Through experiments on Pascal VOC 2010, we show the importance of features learnt from stuff segmentation for improving object detection performance. StuffNet improves performance from 18.8% mAP to 23.9% mAP for small objects. We also devise a method to train StuffNet on datasets that do not have stuff segmentation labels. Through experiments on Pascal VOC 2007 and 2012, we demonstrate the effectiveness of this method and show that StuffNet also significantly improves object detection performance on such datasets.
[ { "version": "v1", "created": "Wed, 19 Oct 2016 04:44:51 GMT" }, { "version": "v2", "created": "Mon, 30 Jan 2017 03:10:20 GMT" } ]
2017-01-31T00:00:00
[ [ "Brahmbhatt", "Samarth", "" ], [ "Christensen", "Henrik I.", "" ], [ "Hays", "James", "" ] ]
TITLE: StuffNet: Using 'Stuff' to Improve Object Detection ABSTRACT: We propose a Convolutional Neural Network (CNN) based algorithm - StuffNet - for object detection. In addition to the standard convolutional features trained for region proposal and object detection [31], StuffNet uses convolutional features trained for segmentation of objects and 'stuff' (amorphous categories such as ground and water). Through experiments on Pascal VOC 2010, we show the importance of features learnt from stuff segmentation for improving object detection performance. StuffNet improves performance from 18.8% mAP to 23.9% mAP for small objects. We also devise a method to train StuffNet on datasets that do not have stuff segmentation labels. Through experiments on Pascal VOC 2007 and 2012, we demonstrate the effectiveness of this method and show that StuffNet also significantly improves object detection performance on such datasets.
no_new_dataset
0.955361
1612.05079
Ankur Handa
John McCormac, Ankur Handa, Stefan Leutenegger, Andrew J. Davison
SceneNet RGB-D: 5M Photorealistic Images of Synthetic Indoor Trajectories with Ground Truth
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We introduce SceneNet RGB-D, expanding the previous work of SceneNet to enable large scale photorealistic rendering of indoor scene trajectories. It provides pixel-perfect ground truth for scene understanding problems such as semantic segmentation, instance segmentation, and object detection, and also for geometric computer vision problems such as optical flow, depth estimation, camera pose estimation, and 3D reconstruction. Random sampling permits virtually unlimited scene configurations, and here we provide a set of 5M rendered RGB-D images from over 15K trajectories in synthetic layouts with random but physically simulated object poses. Each layout also has random lighting, camera trajectories, and textures. The scale of this dataset is well suited for pre-training data-driven computer vision techniques from scratch with RGB-D inputs, which previously has been limited by relatively small labelled datasets in NYUv2 and SUN RGB-D. It also provides a basis for investigating 3D scene labelling tasks by providing perfect camera poses and depth data as proxy for a SLAM system. We host the dataset at http://robotvault.bitbucket.io/scenenet-rgbd.html
[ { "version": "v1", "created": "Thu, 15 Dec 2016 14:22:38 GMT" }, { "version": "v2", "created": "Fri, 16 Dec 2016 01:37:54 GMT" }, { "version": "v3", "created": "Mon, 30 Jan 2017 11:06:14 GMT" } ]
2017-01-31T00:00:00
[ [ "McCormac", "John", "" ], [ "Handa", "Ankur", "" ], [ "Leutenegger", "Stefan", "" ], [ "Davison", "Andrew J.", "" ] ]
TITLE: SceneNet RGB-D: 5M Photorealistic Images of Synthetic Indoor Trajectories with Ground Truth ABSTRACT: We introduce SceneNet RGB-D, expanding the previous work of SceneNet to enable large scale photorealistic rendering of indoor scene trajectories. It provides pixel-perfect ground truth for scene understanding problems such as semantic segmentation, instance segmentation, and object detection, and also for geometric computer vision problems such as optical flow, depth estimation, camera pose estimation, and 3D reconstruction. Random sampling permits virtually unlimited scene configurations, and here we provide a set of 5M rendered RGB-D images from over 15K trajectories in synthetic layouts with random but physically simulated object poses. Each layout also has random lighting, camera trajectories, and textures. The scale of this dataset is well suited for pre-training data-driven computer vision techniques from scratch with RGB-D inputs, which previously has been limited by relatively small labelled datasets in NYUv2 and SUN RGB-D. It also provides a basis for investigating 3D scene labelling tasks by providing perfect camera poses and depth data as proxy for a SLAM system. We host the dataset at http://robotvault.bitbucket.io/scenenet-rgbd.html
new_dataset
0.955068
1701.07368
Zhenzhong Lan
Zhenzhong Lan, Yi Zhu, Alexander G. Hauptmann
Deep Local Video Feature for Action Recognition
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the problem of representing an entire video using CNN features for human action recognition. Currently, limited by GPU memory, we have not been able to feed a whole video into CNN/RNNs for end-to-end learning. A common practice is to use sampled frames as inputs and video labels as supervision. One major problem of this popular approach is that the local samples may not contain the information indicated by global labels. To deal with this problem, we propose to treat the deep networks trained on local inputs as local feature extractors. After extracting local features, we aggregate them into global features and train another mapping function on the same training data to map the global features into global labels. We study a set of problems regarding this new type of local features such as how to aggregate them into global features. Experimental results on HMDB51 and UCF101 datasets show that, for these new local features, a simple maximum pooling on the sparsely sampled features lead to significant performance improvement.
[ { "version": "v1", "created": "Wed, 25 Jan 2017 16:23:17 GMT" }, { "version": "v2", "created": "Sat, 28 Jan 2017 13:50:09 GMT" } ]
2017-01-31T00:00:00
[ [ "Lan", "Zhenzhong", "" ], [ "Zhu", "Yi", "" ], [ "Hauptmann", "Alexander G.", "" ] ]
TITLE: Deep Local Video Feature for Action Recognition ABSTRACT: We investigate the problem of representing an entire video using CNN features for human action recognition. Currently, limited by GPU memory, we have not been able to feed a whole video into CNN/RNNs for end-to-end learning. A common practice is to use sampled frames as inputs and video labels as supervision. One major problem of this popular approach is that the local samples may not contain the information indicated by global labels. To deal with this problem, we propose to treat the deep networks trained on local inputs as local feature extractors. After extracting local features, we aggregate them into global features and train another mapping function on the same training data to map the global features into global labels. We study a set of problems regarding this new type of local features such as how to aggregate them into global features. Experimental results on HMDB51 and UCF101 datasets show that, for these new local features, a simple maximum pooling on the sparsely sampled features lead to significant performance improvement.
no_new_dataset
0.944177
1701.08241
Yansong Gao
Yansong Gao, Hua Ma, Geifei Li, Shaza Zeitouni, Said F. Al-Sarawi, Derek Abbott, Ahmad-Reza Sadeghi, Damith C. Ranasinghe
Exploiting PUF Models for Error Free Response Generation
null
null
null
null
cs.CR
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Physical unclonable functions (PUF) extract secrets from randomness inherent in manufacturing processes. PUFs are utilized for basic cryptographic tasks such as authentication and key generation, and more recently, to realize key exchange and bit commitment requiring a large number of error free responses from a strong PUF. We propose an approach to eliminate the need to implement expensive on-chip error correction logic implementation and the associated helper data storage to reconcile naturally noisy PUF responses. In particular, we exploit a statistical model of an Arbiter PUF (APUF) constructed under the nominal operating condition during the challenge response enrollment phase by a trusted party to judiciously select challenges that yield error-free responses even across a wide operating conditions, specifically, a $ \pm 20\% $ supply voltage variation and a $ 40^{\crc} $ temperature variation. We validate our approach using measurements from two APUF datasets. Experimental results indicate that large number of error-free responses can be generated on demand under worst-case when PUF response error rate is up to 16.68\%.
[ { "version": "v1", "created": "Sat, 28 Jan 2017 03:06:33 GMT" } ]
2017-01-31T00:00:00
[ [ "Gao", "Yansong", "" ], [ "Ma", "Hua", "" ], [ "Li", "Geifei", "" ], [ "Zeitouni", "Shaza", "" ], [ "Al-Sarawi", "Said F.", "" ], [ "Abbott", "Derek", "" ], [ "Sadeghi", "Ahmad-Reza", "" ], [ "Ranasinghe", "Damith C.", "" ] ]
TITLE: Exploiting PUF Models for Error Free Response Generation ABSTRACT: Physical unclonable functions (PUF) extract secrets from randomness inherent in manufacturing processes. PUFs are utilized for basic cryptographic tasks such as authentication and key generation, and more recently, to realize key exchange and bit commitment requiring a large number of error free responses from a strong PUF. We propose an approach to eliminate the need to implement expensive on-chip error correction logic implementation and the associated helper data storage to reconcile naturally noisy PUF responses. In particular, we exploit a statistical model of an Arbiter PUF (APUF) constructed under the nominal operating condition during the challenge response enrollment phase by a trusted party to judiciously select challenges that yield error-free responses even across a wide operating conditions, specifically, a $ \pm 20\% $ supply voltage variation and a $ 40^{\crc} $ temperature variation. We validate our approach using measurements from two APUF datasets. Experimental results indicate that large number of error-free responses can be generated on demand under worst-case when PUF response error rate is up to 16.68\%.
no_new_dataset
0.947039
1701.08291
Ilke Cugu
\.Ilke \c{C}u\u{g}u, Eren \c{S}ener, \c{C}a\u{g}r{\i} Erciyes, Burak Balc{\i}, Emre Ak{\i}n, It{\i}r \"Onal, Ahmet O\u{g}uz Aky\"uz
Treelogy: A Novel Tree Classifier Utilizing Deep and Hand-crafted Representations
null
null
null
null
cs.CV
http://creativecommons.org/licenses/by-nc-sa/4.0/
We propose a novel tree classification system called Treelogy, that fuses deep representations with hand-crafted features obtained from leaf images to perform leaf-based plant classification. Key to this system are segmentation of the leaf from an untextured background, using convolutional neural networks (CNNs) for learning deep representations, extracting hand-crafted features with a number of image processing techniques, training a linear SVM with feature vectors, merging SVM and CNN results, and identifying the species from a dataset of 57 trees. Our classification results show that fusion of deep representations with hand-crafted features leads to the highest accuracy. The proposed algorithm is embedded in a smart-phone application, which is publicly available. Furthermore, our novel dataset comprised of 5408 leaf images is also made public for use of other researchers.
[ { "version": "v1", "created": "Sat, 28 Jan 2017 13:41:49 GMT" } ]
2017-01-31T00:00:00
[ [ "Çuğu", "İlke", "" ], [ "Şener", "Eren", "" ], [ "Erciyes", "Çağrı", "" ], [ "Balcı", "Burak", "" ], [ "Akın", "Emre", "" ], [ "Önal", "Itır", "" ], [ "Akyüz", "Ahmet Oğuz", "" ] ]
TITLE: Treelogy: A Novel Tree Classifier Utilizing Deep and Hand-crafted Representations ABSTRACT: We propose a novel tree classification system called Treelogy, that fuses deep representations with hand-crafted features obtained from leaf images to perform leaf-based plant classification. Key to this system are segmentation of the leaf from an untextured background, using convolutional neural networks (CNNs) for learning deep representations, extracting hand-crafted features with a number of image processing techniques, training a linear SVM with feature vectors, merging SVM and CNN results, and identifying the species from a dataset of 57 trees. Our classification results show that fusion of deep representations with hand-crafted features leads to the highest accuracy. The proposed algorithm is embedded in a smart-phone application, which is publicly available. Furthermore, our novel dataset comprised of 5408 leaf images is also made public for use of other researchers.
new_dataset
0.95877
1701.08318
Xueliang (Leon) Liu
Xueliang Liu
Deep Recurrent Neural Network for Protein Function Prediction from Sequence
null
null
null
null
q-bio.QM cs.LG q-bio.BM stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
As high-throughput biological sequencing becomes faster and cheaper, the need to extract useful information from sequencing becomes ever more paramount, often limited by low-throughput experimental characterizations. For proteins, accurate prediction of their functions directly from their primary amino-acid sequences has been a long standing challenge. Here, machine learning using artificial recurrent neural networks (RNN) was applied towards classification of protein function directly from primary sequence without sequence alignment, heuristic scoring or feature engineering. The RNN models containing long-short-term-memory (LSTM) units trained on public, annotated datasets from UniProt achieved high performance for in-class prediction of four important protein functions tested, particularly compared to other machine learning algorithms using sequence-derived protein features. RNN models were used also for out-of-class predictions of phylogenetically distinct protein families with similar functions, including proteins of the CRISPR-associated nuclease, ferritin-like iron storage and cytochrome P450 families. Applying the trained RNN models on the partially unannotated UniRef100 database predicted not only candidates validated by existing annotations but also currently unannotated sequences. Some RNN predictions for the ferritin-like iron sequestering function were experimentally validated, even though their sequences differ significantly from known, characterized proteins and from each other and cannot be easily predicted using popular bioinformatics methods. As sequencing and experimental characterization data increases rapidly, the machine-learning approach based on RNN could be useful for discovery and prediction of homologues for a wide range of protein functions.
[ { "version": "v1", "created": "Sat, 28 Jan 2017 19:33:59 GMT" } ]
2017-01-31T00:00:00
[ [ "Liu", "Xueliang", "" ] ]
TITLE: Deep Recurrent Neural Network for Protein Function Prediction from Sequence ABSTRACT: As high-throughput biological sequencing becomes faster and cheaper, the need to extract useful information from sequencing becomes ever more paramount, often limited by low-throughput experimental characterizations. For proteins, accurate prediction of their functions directly from their primary amino-acid sequences has been a long standing challenge. Here, machine learning using artificial recurrent neural networks (RNN) was applied towards classification of protein function directly from primary sequence without sequence alignment, heuristic scoring or feature engineering. The RNN models containing long-short-term-memory (LSTM) units trained on public, annotated datasets from UniProt achieved high performance for in-class prediction of four important protein functions tested, particularly compared to other machine learning algorithms using sequence-derived protein features. RNN models were used also for out-of-class predictions of phylogenetically distinct protein families with similar functions, including proteins of the CRISPR-associated nuclease, ferritin-like iron storage and cytochrome P450 families. Applying the trained RNN models on the partially unannotated UniRef100 database predicted not only candidates validated by existing annotations but also currently unannotated sequences. Some RNN predictions for the ferritin-like iron sequestering function were experimentally validated, even though their sequences differ significantly from known, characterized proteins and from each other and cannot be easily predicted using popular bioinformatics methods. As sequencing and experimental characterization data increases rapidly, the machine-learning approach based on RNN could be useful for discovery and prediction of homologues for a wide range of protein functions.
no_new_dataset
0.951142
1701.08380
Martin Thoma
Martin Thoma
The HASYv2 dataset
null
null
null
null
cs.CV
http://creativecommons.org/licenses/by/4.0/
This paper describes the HASYv2 dataset. HASY is a publicly available, free of charge dataset of single symbols similar to MNIST. It contains 168233 instances of 369 classes. HASY contains two challenges: A classification challenge with 10 pre-defined folds for 10-fold cross-validation and a verification challenge.
[ { "version": "v1", "created": "Sun, 29 Jan 2017 13:42:14 GMT" } ]
2017-01-31T00:00:00
[ [ "Thoma", "Martin", "" ] ]
TITLE: The HASYv2 dataset ABSTRACT: This paper describes the HASYv2 dataset. HASY is a publicly available, free of charge dataset of single symbols similar to MNIST. It contains 168233 instances of 369 classes. HASY contains two challenges: A classification challenge with 10 pre-defined folds for 10-fold cross-validation and a verification challenge.
new_dataset
0.959875
1701.08694
Saiful Islam Md
Md. Saiful Islam, Fazla Elahi Md Jubayer and Syed Ikhtiar Ahmed
A Comparative Study on Different Types of Approaches to Bengali document Categorization
6 pages
null
null
null
cs.CL cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Document categorization is a technique where the category of a document is determined. In this paper three well-known supervised learning techniques which are Support Vector Machine(SVM), Na\"ive Bayes(NB) and Stochastic Gradient Descent(SGD) compared for Bengali document categorization. Besides classifier, classification also depends on how feature is selected from dataset. For analyzing those classifier performances on predicting a document against twelve categories several feature selection techniques are also applied in this article namely Chi square distribution, normalized TFIDF (term frequency-inverse document frequency) with word analyzer. So, we attempt to explore the efficiency of those three-classification algorithms by using two different feature selection techniques in this article.
[ { "version": "v1", "created": "Fri, 27 Jan 2017 13:08:08 GMT" } ]
2017-01-31T00:00:00
[ [ "Islam", "Md. Saiful", "" ], [ "Jubayer", "Fazla Elahi Md", "" ], [ "Ahmed", "Syed Ikhtiar", "" ] ]
TITLE: A Comparative Study on Different Types of Approaches to Bengali document Categorization ABSTRACT: Document categorization is a technique where the category of a document is determined. In this paper three well-known supervised learning techniques which are Support Vector Machine(SVM), Na\"ive Bayes(NB) and Stochastic Gradient Descent(SGD) compared for Bengali document categorization. Besides classifier, classification also depends on how feature is selected from dataset. For analyzing those classifier performances on predicting a document against twelve categories several feature selection techniques are also applied in this article namely Chi square distribution, normalized TFIDF (term frequency-inverse document frequency) with word analyzer. So, we attempt to explore the efficiency of those three-classification algorithms by using two different feature selection techniques in this article.
no_new_dataset
0.953362
1604.03489
Xavier Gir\'o-i-Nieto
Victor Campos, Brendan Jou and Xavier Giro-i-Nieto
From Pixels to Sentiment: Fine-tuning CNNs for Visual Sentiment Prediction
Accepted for publication in Image and Vision Computing. Models and source code available at https://github.com/imatge-upc/sentiment-2016
null
null
null
cs.CV cs.MM
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Visual multimedia have become an inseparable part of our digital social lives, and they often capture moments tied with deep affections. Automated visual sentiment analysis tools can provide a means of extracting the rich feelings and latent dispositions embedded in these media. In this work, we explore how Convolutional Neural Networks (CNNs), a now de facto computational machine learning tool particularly in the area of Computer Vision, can be specifically applied to the task of visual sentiment prediction. We accomplish this through fine-tuning experiments using a state-of-the-art CNN and via rigorous architecture analysis, we present several modifications that lead to accuracy improvements over prior art on a dataset of images from a popular social media platform. We additionally present visualizations of local patterns that the network learned to associate with image sentiment for insight into how visual positivity (or negativity) is perceived by the model.
[ { "version": "v1", "created": "Tue, 12 Apr 2016 17:24:39 GMT" }, { "version": "v2", "created": "Fri, 27 Jan 2017 18:02:16 GMT" } ]
2017-01-30T00:00:00
[ [ "Campos", "Victor", "" ], [ "Jou", "Brendan", "" ], [ "Giro-i-Nieto", "Xavier", "" ] ]
TITLE: From Pixels to Sentiment: Fine-tuning CNNs for Visual Sentiment Prediction ABSTRACT: Visual multimedia have become an inseparable part of our digital social lives, and they often capture moments tied with deep affections. Automated visual sentiment analysis tools can provide a means of extracting the rich feelings and latent dispositions embedded in these media. In this work, we explore how Convolutional Neural Networks (CNNs), a now de facto computational machine learning tool particularly in the area of Computer Vision, can be specifically applied to the task of visual sentiment prediction. We accomplish this through fine-tuning experiments using a state-of-the-art CNN and via rigorous architecture analysis, we present several modifications that lead to accuracy improvements over prior art on a dataset of images from a popular social media platform. We additionally present visualizations of local patterns that the network learned to associate with image sentiment for insight into how visual positivity (or negativity) is perceived by the model.
no_new_dataset
0.946547
1608.07102
Qiang Liu
Qiang Liu, Shu Wu, Liang Wang
Multi-behavioral Sequential Prediction with Recurrent Log-bilinear Model
IEEE Transactions on Knowledge and Data Engineering (TKDE), to appear
null
null
null
cs.IR
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
With the rapid growth of Internet applications, sequential prediction in collaborative filtering has become an emerging and crucial task. Given the behavioral history of a specific user, predicting his or her next choice plays a key role in improving various online services. Meanwhile, there are more and more scenarios with multiple types of behaviors, while existing works mainly study sequences with a single type of behavior. As a widely used approach, Markov chain based models are based on a strong independence assumption. As two classical neural network methods for modeling sequences, recurrent neural networks cannot well model short-term contexts, and the log-bilinear model is not suitable for long-term contexts. In this paper, we propose a Recurrent Log-BiLinear (RLBL) model. It can model multiple types of behaviors in historical sequences with behavior-specific transition matrices. RLBL applies a recurrent structure for modeling long-term contexts. It models several items in each hidden layer and employs position-specific transition matrices for modeling short-term contexts. Moreover, considering continuous time difference in behavioral history is a key factor for dynamic prediction, we further extend RLBL and replace position-specific transition matrices with time-specific transition matrices, and accordingly propose a Time-Aware Recurrent Log-BiLinear (TA-RLBL) model. Experimental results show that the proposed RLBL model and TA-RLBL model yield significant improvements over the competitive compared methods on three datasets, i.e., Movielens-1M dataset, Global Terrorism Database and Tmall dataset with different numbers of behavior types.
[ { "version": "v1", "created": "Thu, 25 Aug 2016 12:01:18 GMT" }, { "version": "v2", "created": "Mon, 10 Oct 2016 09:08:40 GMT" }, { "version": "v3", "created": "Thu, 8 Dec 2016 06:58:18 GMT" }, { "version": "v4", "created": "Fri, 27 Jan 2017 09:53:14 GMT" } ]
2017-01-30T00:00:00
[ [ "Liu", "Qiang", "" ], [ "Wu", "Shu", "" ], [ "Wang", "Liang", "" ] ]
TITLE: Multi-behavioral Sequential Prediction with Recurrent Log-bilinear Model ABSTRACT: With the rapid growth of Internet applications, sequential prediction in collaborative filtering has become an emerging and crucial task. Given the behavioral history of a specific user, predicting his or her next choice plays a key role in improving various online services. Meanwhile, there are more and more scenarios with multiple types of behaviors, while existing works mainly study sequences with a single type of behavior. As a widely used approach, Markov chain based models are based on a strong independence assumption. As two classical neural network methods for modeling sequences, recurrent neural networks cannot well model short-term contexts, and the log-bilinear model is not suitable for long-term contexts. In this paper, we propose a Recurrent Log-BiLinear (RLBL) model. It can model multiple types of behaviors in historical sequences with behavior-specific transition matrices. RLBL applies a recurrent structure for modeling long-term contexts. It models several items in each hidden layer and employs position-specific transition matrices for modeling short-term contexts. Moreover, considering continuous time difference in behavioral history is a key factor for dynamic prediction, we further extend RLBL and replace position-specific transition matrices with time-specific transition matrices, and accordingly propose a Time-Aware Recurrent Log-BiLinear (TA-RLBL) model. Experimental results show that the proposed RLBL model and TA-RLBL model yield significant improvements over the competitive compared methods on three datasets, i.e., Movielens-1M dataset, Global Terrorism Database and Tmall dataset with different numbers of behavior types.
no_new_dataset
0.953579
1611.04741
K. M. Annervaz
Biswajit Paria, K. M. Annervaz, Ambedkar Dukkipati, Ankush Chatterjee, Sanjay Podder
A Neural Architecture Mimicking Humans End-to-End for Natural Language Inference
8 pages, 2 figures
null
null
null
cs.CL
http://creativecommons.org/publicdomain/zero/1.0/
In this work we use the recent advances in representation learning to propose a neural architecture for the problem of natural language inference. Our approach is aligned to mimic how a human does the natural language inference process given two statements. The model uses variants of Long Short Term Memory (LSTM), attention mechanism and composable neural networks, to carry out the task. Each part of our model can be mapped to a clear functionality humans do for carrying out the overall task of natural language inference. The model is end-to-end differentiable enabling training by stochastic gradient descent. On Stanford Natural Language Inference(SNLI) dataset, the proposed model achieves better accuracy numbers than all published models in literature.
[ { "version": "v1", "created": "Tue, 15 Nov 2016 08:48:22 GMT" }, { "version": "v2", "created": "Fri, 27 Jan 2017 05:36:05 GMT" } ]
2017-01-30T00:00:00
[ [ "Paria", "Biswajit", "" ], [ "Annervaz", "K. M.", "" ], [ "Dukkipati", "Ambedkar", "" ], [ "Chatterjee", "Ankush", "" ], [ "Podder", "Sanjay", "" ] ]
TITLE: A Neural Architecture Mimicking Humans End-to-End for Natural Language Inference ABSTRACT: In this work we use the recent advances in representation learning to propose a neural architecture for the problem of natural language inference. Our approach is aligned to mimic how a human does the natural language inference process given two statements. The model uses variants of Long Short Term Memory (LSTM), attention mechanism and composable neural networks, to carry out the task. Each part of our model can be mapped to a clear functionality humans do for carrying out the overall task of natural language inference. The model is end-to-end differentiable enabling training by stochastic gradient descent. On Stanford Natural Language Inference(SNLI) dataset, the proposed model achieves better accuracy numbers than all published models in literature.
no_new_dataset
0.951188
1611.09630
Jakub Tomczak Ph.D.
Jakub M. Tomczak and Max Welling
Improving Variational Auto-Encoders using Householder Flow
A corrected version of the paper submitted to Bayesian Deep Learning Workshop (NIPS 2016)
null
null
null
cs.LG stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Variational auto-encoders (VAE) are scalable and powerful generative models. However, the choice of the variational posterior determines tractability and flexibility of the VAE. Commonly, latent variables are modeled using the normal distribution with a diagonal covariance matrix. This results in computational efficiency but typically it is not flexible enough to match the true posterior distribution. One fashion of enriching the variational posterior distribution is application of normalizing flows, i.e., a series of invertible transformations to latent variables with a simple posterior. In this paper, we follow this line of thinking and propose a volume-preserving flow that uses a series of Householder transformations. We show empirically on MNIST dataset and histopathology data that the proposed flow allows to obtain more flexible variational posterior and competitive results comparing to other normalizing flows.
[ { "version": "v1", "created": "Tue, 29 Nov 2016 13:49:31 GMT" }, { "version": "v2", "created": "Wed, 7 Dec 2016 12:04:28 GMT" }, { "version": "v3", "created": "Sun, 22 Jan 2017 18:49:14 GMT" }, { "version": "v4", "created": "Fri, 27 Jan 2017 00:36:51 GMT" } ]
2017-01-30T00:00:00
[ [ "Tomczak", "Jakub M.", "" ], [ "Welling", "Max", "" ] ]
TITLE: Improving Variational Auto-Encoders using Householder Flow ABSTRACT: Variational auto-encoders (VAE) are scalable and powerful generative models. However, the choice of the variational posterior determines tractability and flexibility of the VAE. Commonly, latent variables are modeled using the normal distribution with a diagonal covariance matrix. This results in computational efficiency but typically it is not flexible enough to match the true posterior distribution. One fashion of enriching the variational posterior distribution is application of normalizing flows, i.e., a series of invertible transformations to latent variables with a simple posterior. In this paper, we follow this line of thinking and propose a volume-preserving flow that uses a series of Householder transformations. We show empirically on MNIST dataset and histopathology data that the proposed flow allows to obtain more flexible variational posterior and competitive results comparing to other normalizing flows.
no_new_dataset
0.950088
1701.07901
Jingkuan Song Dr.
Jingkuan Song, Tao He, Lianli Gao, Xing Xu, Heng Tao Shen
Deep Region Hashing for Efficient Large-scale Instance Search from Images
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Instance Search (INS) is a fundamental problem for many applications, while it is more challenging comparing to traditional image search since the relevancy is defined at the instance level. Existing works have demonstrated the success of many complex ensemble systems that are typically conducted by firstly generating object proposals, and then extracting handcrafted and/or CNN features of each proposal for matching. However, object bounding box proposals and feature extraction are often conducted in two separated steps, thus the effectiveness of these methods collapses. Also, due to the large amount of generated proposals, matching speed becomes the bottleneck that limits its application to large-scale datasets. To tackle these issues, in this paper we propose an effective and efficient Deep Region Hashing (DRH) approach for large-scale INS using an image patch as the query. Specifically, DRH is an end-to-end deep neural network which consists of object proposal, feature extraction, and hash code generation. DRH shares full-image convolutional feature map with the region proposal network, thus enabling nearly cost-free region proposals. Also, each high-dimensional, real-valued region features are mapped onto a low-dimensional, compact binary codes for the efficient object region level matching on large-scale dataset. Experimental results on four datasets show that our DRH can achieve even better performance than the state-of-the-arts in terms of MAP, while the efficiency is improved by nearly 100 times.
[ { "version": "v1", "created": "Thu, 26 Jan 2017 23:18:58 GMT" } ]
2017-01-30T00:00:00
[ [ "Song", "Jingkuan", "" ], [ "He", "Tao", "" ], [ "Gao", "Lianli", "" ], [ "Xu", "Xing", "" ], [ "Shen", "Heng Tao", "" ] ]
TITLE: Deep Region Hashing for Efficient Large-scale Instance Search from Images ABSTRACT: Instance Search (INS) is a fundamental problem for many applications, while it is more challenging comparing to traditional image search since the relevancy is defined at the instance level. Existing works have demonstrated the success of many complex ensemble systems that are typically conducted by firstly generating object proposals, and then extracting handcrafted and/or CNN features of each proposal for matching. However, object bounding box proposals and feature extraction are often conducted in two separated steps, thus the effectiveness of these methods collapses. Also, due to the large amount of generated proposals, matching speed becomes the bottleneck that limits its application to large-scale datasets. To tackle these issues, in this paper we propose an effective and efficient Deep Region Hashing (DRH) approach for large-scale INS using an image patch as the query. Specifically, DRH is an end-to-end deep neural network which consists of object proposal, feature extraction, and hash code generation. DRH shares full-image convolutional feature map with the region proposal network, thus enabling nearly cost-free region proposals. Also, each high-dimensional, real-valued region features are mapped onto a low-dimensional, compact binary codes for the efficient object region level matching on large-scale dataset. Experimental results on four datasets show that our DRH can achieve even better performance than the state-of-the-arts in terms of MAP, while the efficiency is improved by nearly 100 times.
no_new_dataset
0.949059
1701.08022
Sebastian Deorowicz
Marek Kokot and Maciej D{\l}ugosz and Sebastian Deorowicz
KMC 3: counting and manipulating k-mer statistics
null
null
null
null
q-bio.GN cs.DC cs.DS
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Summary: Counting all k-mers in a given dataset is a standard procedure in many bioinformatics applications. We introduce KMC3, a significant improvement of the former KMC2 algorithm together with KMC tools for manipulating k-mer databases. Usefulness of the tools is shown on a few real problems. Availability: Program is freely available at http://sun.aei.polsl.pl/REFRESH/kmc. Contact: [email protected]
[ { "version": "v1", "created": "Fri, 27 Jan 2017 12:04:30 GMT" } ]
2017-01-30T00:00:00
[ [ "Kokot", "Marek", "" ], [ "Długosz", "Maciej", "" ], [ "Deorowicz", "Sebastian", "" ] ]
TITLE: KMC 3: counting and manipulating k-mer statistics ABSTRACT: Summary: Counting all k-mers in a given dataset is a standard procedure in many bioinformatics applications. We introduce KMC3, a significant improvement of the former KMC2 algorithm together with KMC tools for manipulating k-mer databases. Usefulness of the tools is shown on a few real problems. Availability: Program is freely available at http://sun.aei.polsl.pl/REFRESH/kmc. Contact: [email protected]
no_new_dataset
0.944791
1701.08128
Gabriele Santi Mr
Gabriele Santi and Leonardo De Laurentiis
Evaluating a sublinear-time algorithm for the Minimum Spanning Tree Weight problem
23 pages, 13 figures, project developed during Master's Degree studies
null
null
null
cs.DS
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present an implementation and an experimental evaluation of an algorithm that, given a connected graph G (represented by adjacency lists), estimates in sublinear time, with a relative error, the Minimum Spanning Tree Weight of G; the original algorithm has been presented in "Approximating the minimum spanning tree weight in sublinear time", by Bernard Chazelle, Ronitt Rubinfeld, and Luca Trevisan (published with SIAM, DOI 10.1137/S0097539702403244). Since the theoretical performances have already been shown and demonstrated in the above-mentioned paper, our goal is, exclusively, to experimental evaluate the algorithm and at last to present the results. Initially we discuss about some theoretical aspects that arose while we were valuating the asymptotic complexity of our specific implementation. Some technical insights are then given on the implementation of the algorithm and on the dataset used in the test phase, hence to show how the experiment has been carried out even for reproducibility purposes; the results are then evaluated empirically and widely discussed, comparing these with the performances of the Prim algorithm and the Kruskal algorithm, launching several runs on a heterogeneous set of graphs and different theoretical models for them.
[ { "version": "v1", "created": "Fri, 27 Jan 2017 17:45:04 GMT" } ]
2017-01-30T00:00:00
[ [ "Santi", "Gabriele", "" ], [ "De Laurentiis", "Leonardo", "" ] ]
TITLE: Evaluating a sublinear-time algorithm for the Minimum Spanning Tree Weight problem ABSTRACT: We present an implementation and an experimental evaluation of an algorithm that, given a connected graph G (represented by adjacency lists), estimates in sublinear time, with a relative error, the Minimum Spanning Tree Weight of G; the original algorithm has been presented in "Approximating the minimum spanning tree weight in sublinear time", by Bernard Chazelle, Ronitt Rubinfeld, and Luca Trevisan (published with SIAM, DOI 10.1137/S0097539702403244). Since the theoretical performances have already been shown and demonstrated in the above-mentioned paper, our goal is, exclusively, to experimental evaluate the algorithm and at last to present the results. Initially we discuss about some theoretical aspects that arose while we were valuating the asymptotic complexity of our specific implementation. Some technical insights are then given on the implementation of the algorithm and on the dataset used in the test phase, hence to show how the experiment has been carried out even for reproducibility purposes; the results are then evaluated empirically and widely discussed, comparing these with the performances of the Prim algorithm and the Kruskal algorithm, launching several runs on a heterogeneous set of graphs and different theoretical models for them.
no_new_dataset
0.940463
1507.04921
Chi Ho Yeung
Chi Ho Yeung
Do recommender systems benefit users?
15 pages, 6 figures
J. Stat. Mech. 043401 (2016)
10.1088/1742-5468/2016/04/043401
null
cs.CY cs.IR cs.SI physics.soc-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recommender systems are present in many web applications to guide our choices. They increase sales and benefit sellers, but whether they benefit customers by providing relevant products is questionable. Here we introduce a model to examine the benefit of recommender systems for users, and found that recommendations from the system can be equivalent to random draws if one relies too strongly on the system. Nevertheless, with sufficient information about user preferences, recommendations become accurate and an abrupt transition to this accurate regime is observed for some algorithms. On the other hand, we found that a high accuracy evaluated by common accuracy metrics does not necessarily correspond to a high real accuracy nor a benefit for users, which serves as an alarm for operators and researchers of recommender systems. We tested our model with a real dataset and observed similar behaviors. Finally, a recommendation approach with improved accuracy is suggested. These results imply that recommender systems can benefit users, but relying too strongly on the system may render the system ineffective.
[ { "version": "v1", "created": "Sun, 5 Jul 2015 14:56:11 GMT" } ]
2017-01-27T00:00:00
[ [ "Yeung", "Chi Ho", "" ] ]
TITLE: Do recommender systems benefit users? ABSTRACT: Recommender systems are present in many web applications to guide our choices. They increase sales and benefit sellers, but whether they benefit customers by providing relevant products is questionable. Here we introduce a model to examine the benefit of recommender systems for users, and found that recommendations from the system can be equivalent to random draws if one relies too strongly on the system. Nevertheless, with sufficient information about user preferences, recommendations become accurate and an abrupt transition to this accurate regime is observed for some algorithms. On the other hand, we found that a high accuracy evaluated by common accuracy metrics does not necessarily correspond to a high real accuracy nor a benefit for users, which serves as an alarm for operators and researchers of recommender systems. We tested our model with a real dataset and observed similar behaviors. Finally, a recommendation approach with improved accuracy is suggested. These results imply that recommender systems can benefit users, but relying too strongly on the system may render the system ineffective.
no_new_dataset
0.949856
1701.07483
Ashwin Venkataraman
Srikanth Jagabathula, Lakshminarayanan Subramanian, Ashwin Venkataraman
A Model-based Projection Technique for Segmenting Customers
51 pages, 3 figures, 4 tables
null
null
null
stat.ME cs.LG stat.AP stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the problem of segmenting a large population of customers into non-overlapping groups with similar preferences, using diverse preference observations such as purchases, ratings, clicks, etc. over subsets of items. We focus on the setting where the universe of items is large (ranging from thousands to millions) and unstructured (lacking well-defined attributes) and each customer provides observations for only a few items. These data characteristics limit the applicability of existing techniques in marketing and machine learning. To overcome these limitations, we propose a model-based projection technique, which transforms the diverse set of observations into a more comparable scale and deals with missing data by projecting the transformed data onto a low-dimensional space. We then cluster the projected data to obtain the customer segments. Theoretically, we derive precise necessary and sufficient conditions that guarantee asymptotic recovery of the true customer segments. Empirically, we demonstrate the speed and performance of our method in two real-world case studies: (a) 84% improvement in the accuracy of new movie recommendations on the MovieLens data set and (b) 6% improvement in the performance of similar item recommendations algorithm on an offline dataset at eBay. We show that our method outperforms standard latent-class and demographic-based techniques.
[ { "version": "v1", "created": "Wed, 25 Jan 2017 20:47:40 GMT" } ]
2017-01-27T00:00:00
[ [ "Jagabathula", "Srikanth", "" ], [ "Subramanian", "Lakshminarayanan", "" ], [ "Venkataraman", "Ashwin", "" ] ]
TITLE: A Model-based Projection Technique for Segmenting Customers ABSTRACT: We consider the problem of segmenting a large population of customers into non-overlapping groups with similar preferences, using diverse preference observations such as purchases, ratings, clicks, etc. over subsets of items. We focus on the setting where the universe of items is large (ranging from thousands to millions) and unstructured (lacking well-defined attributes) and each customer provides observations for only a few items. These data characteristics limit the applicability of existing techniques in marketing and machine learning. To overcome these limitations, we propose a model-based projection technique, which transforms the diverse set of observations into a more comparable scale and deals with missing data by projecting the transformed data onto a low-dimensional space. We then cluster the projected data to obtain the customer segments. Theoretically, we derive precise necessary and sufficient conditions that guarantee asymptotic recovery of the true customer segments. Empirically, we demonstrate the speed and performance of our method in two real-world case studies: (a) 84% improvement in the accuracy of new movie recommendations on the MovieLens data set and (b) 6% improvement in the performance of similar item recommendations algorithm on an offline dataset at eBay. We show that our method outperforms standard latent-class and demographic-based techniques.
no_new_dataset
0.948822
1701.07490
RoopTeja Muppalla
Michele Miller, Dr. Tanvi Banerjee, RoopTeja Muppalla, Dr. William Romine, Dr. Amit Sheth
What Are People Tweeting about Zika? An Exploratory Study Concerning Symptoms, Treatment, Transmission, and Prevention
null
null
null
null
cs.SI q-bio.OT
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The purpose of this study was to do a dataset distribution analysis, a classification performance analysis, and a topical analysis concerning what people are tweeting about four disease characteristics: symptoms, transmission, prevention, and treatment. A combination of natural language processing and machine learning techniques were used to determine what people are tweeting about Zika. Specifically, a two-stage classifier system was built to find relevant tweets on Zika, and then categorize these into the four disease categories. Tweets in each disease category were then examined using latent dirichlet allocation (LDA) to determine the five main tweet topics for each disease characteristic. Results 1,234,605 tweets were collected. Tweets by males and females were similar (28% and 23% respectively). The classifier performed well on the training and test data for relevancy (F=0.87 and 0.99 respectively) and disease characteristics (F=0.79 and 0.90 respectively). Five topics for each category were found and discussed with a focus on the symptoms category. Through this process, we demonstrate how misinformation can be discovered so that public health officials can respond to the tweets with misinformation.
[ { "version": "v1", "created": "Tue, 17 Jan 2017 18:52:22 GMT" } ]
2017-01-27T00:00:00
[ [ "Miller", "Michele", "" ], [ "Banerjee", "Dr. Tanvi", "" ], [ "Muppalla", "RoopTeja", "" ], [ "Romine", "Dr. William", "" ], [ "Sheth", "Dr. Amit", "" ] ]
TITLE: What Are People Tweeting about Zika? An Exploratory Study Concerning Symptoms, Treatment, Transmission, and Prevention ABSTRACT: The purpose of this study was to do a dataset distribution analysis, a classification performance analysis, and a topical analysis concerning what people are tweeting about four disease characteristics: symptoms, transmission, prevention, and treatment. A combination of natural language processing and machine learning techniques were used to determine what people are tweeting about Zika. Specifically, a two-stage classifier system was built to find relevant tweets on Zika, and then categorize these into the four disease categories. Tweets in each disease category were then examined using latent dirichlet allocation (LDA) to determine the five main tweet topics for each disease characteristic. Results 1,234,605 tweets were collected. Tweets by males and females were similar (28% and 23% respectively). The classifier performed well on the training and test data for relevancy (F=0.87 and 0.99 respectively) and disease characteristics (F=0.79 and 0.90 respectively). Five topics for each category were found and discussed with a focus on the symptoms category. Through this process, we demonstrate how misinformation can be discovered so that public health officials can respond to the tweets with misinformation.
no_new_dataset
0.946646
1701.07732
Liang Zheng
Liang Zheng, Yujia Huang, Huchuan Lu, Yi Yang
Pose Invariant Embedding for Deep Person Re-identification
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Pedestrian misalignment, which mainly arises from detector errors and pose variations, is a critical problem for a robust person re-identification (re-ID) system. With bad alignment, the background noise will significantly compromise the feature learning and matching process. To address this problem, this paper introduces the pose invariant embedding (PIE) as a pedestrian descriptor. First, in order to align pedestrians to a standard pose, the PoseBox structure is introduced, which is generated through pose estimation followed by affine transformations. Second, to reduce the impact of pose estimation errors and information loss during PoseBox construction, we design a PoseBox fusion (PBF) CNN architecture that takes the original image, the PoseBox, and the pose estimation confidence as input. The proposed PIE descriptor is thus defined as the fully connected layer of the PBF network for the retrieval task. Experiments are conducted on the Market-1501, CUHK03, and VIPeR datasets. We show that PoseBox alone yields decent re-ID accuracy and that when integrated in the PBF network, the learned PIE descriptor produces competitive performance compared with the state-of-the-art approaches.
[ { "version": "v1", "created": "Thu, 26 Jan 2017 14:59:19 GMT" } ]
2017-01-27T00:00:00
[ [ "Zheng", "Liang", "" ], [ "Huang", "Yujia", "" ], [ "Lu", "Huchuan", "" ], [ "Yang", "Yi", "" ] ]
TITLE: Pose Invariant Embedding for Deep Person Re-identification ABSTRACT: Pedestrian misalignment, which mainly arises from detector errors and pose variations, is a critical problem for a robust person re-identification (re-ID) system. With bad alignment, the background noise will significantly compromise the feature learning and matching process. To address this problem, this paper introduces the pose invariant embedding (PIE) as a pedestrian descriptor. First, in order to align pedestrians to a standard pose, the PoseBox structure is introduced, which is generated through pose estimation followed by affine transformations. Second, to reduce the impact of pose estimation errors and information loss during PoseBox construction, we design a PoseBox fusion (PBF) CNN architecture that takes the original image, the PoseBox, and the pose estimation confidence as input. The proposed PIE descriptor is thus defined as the fully connected layer of the PBF network for the retrieval task. Experiments are conducted on the Market-1501, CUHK03, and VIPeR datasets. We show that PoseBox alone yields decent re-ID accuracy and that when integrated in the PBF network, the learned PIE descriptor produces competitive performance compared with the state-of-the-art approaches.
no_new_dataset
0.946892
1701.07773
Bodhitha Jayatilaka
S. Amerio, S. Behari, J. Boyd, M. Brochmann, R. Culbertson, M. Diesburg, J. Freeman, L. Garren, H. Greenlee, K. Herner, R. Illingworth, B. Jayatilaka, A. Jonckheere, Q. Li, S. Naymola, G. Oleynik, W. Sakumotob, E. Varnes, C. Vellidis, G. Watts, S. White
Data preservation at the Fermilab Tevatron
null
Nucl. Instrum. Methods Phys. Res. Sect. A, 851, 1 (2017)
10.1016/j.nima.2017.01.043
FERMILAB-PUB-16-552-CD
hep-ex physics.ins-det
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Fermilab Tevatron collider's data-taking run ended in September 2011, yielding a dataset with rich scientific potential. The CDF and D0 experiments each have approximately 9 PB of collider and simulated data stored on tape. A large computing infrastructure consisting of tape storage, disk cache, and distributed grid computing for physics analysis with the Tevatron data is present at Fermilab. The Fermilab Run II data preservation project intends to keep this analysis capability sustained through the year 2020 and beyond. To achieve this goal, we have implemented a system that utilizes virtualization, automated validation, and migration to new standards in both software and data storage technology and leverages resources available from currently-running experiments at Fermilab. These efforts have also provided useful lessons in ensuring long-term data access for numerous experiments, and enable high-quality scientific output for years to come.
[ { "version": "v1", "created": "Thu, 26 Jan 2017 16:54:34 GMT" } ]
2017-01-27T00:00:00
[ [ "Amerio", "S.", "" ], [ "Behari", "S.", "" ], [ "Boyd", "J.", "" ], [ "Brochmann", "M.", "" ], [ "Culbertson", "R.", "" ], [ "Diesburg", "M.", "" ], [ "Freeman", "J.", "" ], [ "Garren", "L.", "" ], [ "Greenlee", "H.", "" ], [ "Herner", "K.", "" ], [ "Illingworth", "R.", "" ], [ "Jayatilaka", "B.", "" ], [ "Jonckheere", "A.", "" ], [ "Li", "Q.", "" ], [ "Naymola", "S.", "" ], [ "Oleynik", "G.", "" ], [ "Sakumotob", "W.", "" ], [ "Varnes", "E.", "" ], [ "Vellidis", "C.", "" ], [ "Watts", "G.", "" ], [ "White", "S.", "" ] ]
TITLE: Data preservation at the Fermilab Tevatron ABSTRACT: The Fermilab Tevatron collider's data-taking run ended in September 2011, yielding a dataset with rich scientific potential. The CDF and D0 experiments each have approximately 9 PB of collider and simulated data stored on tape. A large computing infrastructure consisting of tape storage, disk cache, and distributed grid computing for physics analysis with the Tevatron data is present at Fermilab. The Fermilab Run II data preservation project intends to keep this analysis capability sustained through the year 2020 and beyond. To achieve this goal, we have implemented a system that utilizes virtualization, automated validation, and migration to new standards in both software and data storage technology and leverages resources available from currently-running experiments at Fermilab. These efforts have also provided useful lessons in ensuring long-term data access for numerous experiments, and enable high-quality scientific output for years to come.
no_new_dataset
0.938294
1602.03468
Abdolrahim Kadkhodamohammadi
Abdolrahim Kadkhodamohammadi, Afshin Gangi, Michel de Mathelin and Nicolas Padoy
Articulated Clinician Detection Using 3D Pictorial Structures on RGB-D Data
The supplementary video is available at https://youtu.be/iabbGSqRSgE
null
10.1016/j.media.2016.07.001
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Reliable human pose estimation (HPE) is essential to many clinical applications, such as surgical workflow analysis, radiation safety monitoring and human-robot cooperation. Proposed methods for the operating room (OR) rely either on foreground estimation using a multi-camera system, which is a challenge in real ORs due to color similarities and frequent illumination changes, or on wearable sensors or markers, which are invasive and therefore difficult to introduce in the room. Instead, we propose a novel approach based on Pictorial Structures (PS) and on RGB-D data, which can be easily deployed in real ORs. We extend the PS framework in two ways. First, we build robust and discriminative part detectors using both color and depth images. We also present a novel descriptor for depth images, called histogram of depth differences (HDD). Second, we extend PS to 3D by proposing 3D pairwise constraints and a new method that makes exact inference tractable. Our approach is evaluated for pose estimation and clinician detection on a challenging RGB-D dataset recorded in a busy operating room during live surgeries. We conduct series of experiments to study the different part detectors in conjunction with the various 2D or 3D pairwise constraints. Our comparisons demonstrate that 3D PS with RGB-D part detectors significantly improves the results in a visually challenging operating environment.
[ { "version": "v1", "created": "Wed, 10 Feb 2016 17:56:47 GMT" }, { "version": "v2", "created": "Mon, 22 Feb 2016 17:57:18 GMT" }, { "version": "v3", "created": "Mon, 4 Jul 2016 08:56:24 GMT" }, { "version": "v4", "created": "Wed, 6 Jul 2016 07:45:15 GMT" } ]
2017-01-26T00:00:00
[ [ "Kadkhodamohammadi", "Abdolrahim", "" ], [ "Gangi", "Afshin", "" ], [ "de Mathelin", "Michel", "" ], [ "Padoy", "Nicolas", "" ] ]
TITLE: Articulated Clinician Detection Using 3D Pictorial Structures on RGB-D Data ABSTRACT: Reliable human pose estimation (HPE) is essential to many clinical applications, such as surgical workflow analysis, radiation safety monitoring and human-robot cooperation. Proposed methods for the operating room (OR) rely either on foreground estimation using a multi-camera system, which is a challenge in real ORs due to color similarities and frequent illumination changes, or on wearable sensors or markers, which are invasive and therefore difficult to introduce in the room. Instead, we propose a novel approach based on Pictorial Structures (PS) and on RGB-D data, which can be easily deployed in real ORs. We extend the PS framework in two ways. First, we build robust and discriminative part detectors using both color and depth images. We also present a novel descriptor for depth images, called histogram of depth differences (HDD). Second, we extend PS to 3D by proposing 3D pairwise constraints and a new method that makes exact inference tractable. Our approach is evaluated for pose estimation and clinician detection on a challenging RGB-D dataset recorded in a busy operating room during live surgeries. We conduct series of experiments to study the different part detectors in conjunction with the various 2D or 3D pairwise constraints. Our comparisons demonstrate that 3D PS with RGB-D part detectors significantly improves the results in a visually challenging operating environment.
no_new_dataset
0.944893
1612.01725
Ron Slossberg
Ron Slossberg, Aaron Wetzler and Ron Kimmel
Deep Stereo Matching with Dense CRF Priors
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Stereo reconstruction from rectified images has recently been revisited within the context of deep learning. Using a deep Convolutional Neural Network to obtain patch-wise matching cost volumes has resulted in state of the art stereo reconstruction on classic datasets like Middlebury and Kitti. By introducing this cost into a classical stereo pipeline, the final results are improved dramatically over non-learning based cost models. However these pipelines typically include hand engineered post processing steps to effectively regularize and clean the result. Here, we show that it is possible to take a more holistic approach by training a fully end-to-end network which directly includes regularization in the form of a densely connected Conditional Random Field (CRF) that acts as a prior on inter-pixel interactions. We demonstrate that our approach on both synthetic and real world datasets outperforms an alternative end-to-end network and compares favorably to more hand engineered approaches.
[ { "version": "v1", "created": "Tue, 6 Dec 2016 09:51:21 GMT" }, { "version": "v2", "created": "Tue, 24 Jan 2017 20:08:28 GMT" } ]
2017-01-26T00:00:00
[ [ "Slossberg", "Ron", "" ], [ "Wetzler", "Aaron", "" ], [ "Kimmel", "Ron", "" ] ]
TITLE: Deep Stereo Matching with Dense CRF Priors ABSTRACT: Stereo reconstruction from rectified images has recently been revisited within the context of deep learning. Using a deep Convolutional Neural Network to obtain patch-wise matching cost volumes has resulted in state of the art stereo reconstruction on classic datasets like Middlebury and Kitti. By introducing this cost into a classical stereo pipeline, the final results are improved dramatically over non-learning based cost models. However these pipelines typically include hand engineered post processing steps to effectively regularize and clean the result. Here, we show that it is possible to take a more holistic approach by training a fully end-to-end network which directly includes regularization in the form of a densely connected Conditional Random Field (CRF) that acts as a prior on inter-pixel interactions. We demonstrate that our approach on both synthetic and real world datasets outperforms an alternative end-to-end network and compares favorably to more hand engineered approaches.
no_new_dataset
0.949482
1701.07114
Nayyar Zaidi
Nayyar A. Zaidi, Yang Du, Geoffrey I. Webb
On the Effectiveness of Discretizing Quantitative Attributes in Linear Classifiers
null
null
null
null
cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Learning algorithms that learn linear models often have high representation bias on real-world problems. In this paper, we show that this representation bias can be greatly reduced by discretization. Discretization is a common procedure in machine learning that is used to convert a quantitative attribute into a qualitative one. It is often motivated by the limitation of some learners to qualitative data. Discretization loses information, as fewer distinctions between instances are possible using discretized data relative to undiscretized data. In consequence, where discretization is not essential, it might appear desirable to avoid it. However, it has been shown that discretization often substantially reduces the error of the linear generative Bayesian classifier naive Bayes. This motivates a systematic study of the effectiveness of discretizing quantitative attributes for other linear classifiers. In this work, we study the effect of discretization on the performance of linear classifiers optimizing three distinct discriminative objective functions --- logistic regression (optimizing negative log-likelihood), support vector classifiers (optimizing hinge loss) and a zero-hidden layer artificial neural network (optimizing mean-square-error). We show that discretization can greatly increase the accuracy of these linear discriminative learners by reducing their representation bias, especially on big datasets. We substantiate our claims with an empirical study on $42$ benchmark datasets.
[ { "version": "v1", "created": "Tue, 24 Jan 2017 23:57:32 GMT" } ]
2017-01-26T00:00:00
[ [ "Zaidi", "Nayyar A.", "" ], [ "Du", "Yang", "" ], [ "Webb", "Geoffrey I.", "" ] ]
TITLE: On the Effectiveness of Discretizing Quantitative Attributes in Linear Classifiers ABSTRACT: Learning algorithms that learn linear models often have high representation bias on real-world problems. In this paper, we show that this representation bias can be greatly reduced by discretization. Discretization is a common procedure in machine learning that is used to convert a quantitative attribute into a qualitative one. It is often motivated by the limitation of some learners to qualitative data. Discretization loses information, as fewer distinctions between instances are possible using discretized data relative to undiscretized data. In consequence, where discretization is not essential, it might appear desirable to avoid it. However, it has been shown that discretization often substantially reduces the error of the linear generative Bayesian classifier naive Bayes. This motivates a systematic study of the effectiveness of discretizing quantitative attributes for other linear classifiers. In this work, we study the effect of discretization on the performance of linear classifiers optimizing three distinct discriminative objective functions --- logistic regression (optimizing negative log-likelihood), support vector classifiers (optimizing hinge loss) and a zero-hidden layer artificial neural network (optimizing mean-square-error). We show that discretization can greatly increase the accuracy of these linear discriminative learners by reducing their representation bias, especially on big datasets. We substantiate our claims with an empirical study on $42$ benchmark datasets.
no_new_dataset
0.943504
1701.07194
Dacheng Tao
Shan You, Chang Xu, Yunhe Wang, Chao Xu, Dacheng Tao
Privileged Multi-label Learning
null
null
null
null
stat.ML cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper presents privileged multi-label learning (PrML) to explore and exploit the relationship between labels in multi-label learning problems. We suggest that for each individual label, it cannot only be implicitly connected with other labels via the low-rank constraint over label predictors, but also its performance on examples can receive the explicit comments from other labels together acting as an \emph{Oracle teacher}. We generate privileged label feature for each example and its individual label, and then integrate it into the framework of low-rank based multi-label learning. The proposed algorithm can therefore comprehensively explore and exploit label relationships by inheriting all the merits of privileged information and low-rank constraints. We show that PrML can be efficiently solved by dual coordinate descent algorithm using iterative optimization strategy with cheap updates. Experiments on benchmark datasets show that through privileged label features, the performance can be significantly improved and PrML is superior to several competing methods in most cases.
[ { "version": "v1", "created": "Wed, 25 Jan 2017 07:43:13 GMT" } ]
2017-01-26T00:00:00
[ [ "You", "Shan", "" ], [ "Xu", "Chang", "" ], [ "Wang", "Yunhe", "" ], [ "Xu", "Chao", "" ], [ "Tao", "Dacheng", "" ] ]
TITLE: Privileged Multi-label Learning ABSTRACT: This paper presents privileged multi-label learning (PrML) to explore and exploit the relationship between labels in multi-label learning problems. We suggest that for each individual label, it cannot only be implicitly connected with other labels via the low-rank constraint over label predictors, but also its performance on examples can receive the explicit comments from other labels together acting as an \emph{Oracle teacher}. We generate privileged label feature for each example and its individual label, and then integrate it into the framework of low-rank based multi-label learning. The proposed algorithm can therefore comprehensively explore and exploit label relationships by inheriting all the merits of privileged information and low-rank constraints. We show that PrML can be efficiently solved by dual coordinate descent algorithm using iterative optimization strategy with cheap updates. Experiments on benchmark datasets show that through privileged label features, the performance can be significantly improved and PrML is superior to several competing methods in most cases.
no_new_dataset
0.946448
1701.07221
Polina Rozenshtein
Aristides Gionis, Polina Rozenshtein, Nikolaj Tatti and Evimaria Terzi
Community-aware network sparsification
null
null
null
null
cs.SI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Network sparsification aims to reduce the number of edges of a network while maintaining its structural properties; such properties include shortest paths, cuts, spectral measures, or network modularity. Sparsification has multiple applications, such as, speeding up graph-mining algorithms, graph visualization, as well as identifying the important network edges. In this paper we consider a novel formulation of the network-sparsification problem. In addition to the network, we also consider as input a set of communities. The goal is to sparsify the network so as to preserve the network structure with respect to the given communities. We introduce two variants of the community-aware sparsification problem, leading to sparsifiers that satisfy different connectedness community properties. From the technical point of view, we prove hardness results and devise effective approximation algorithms. Our experimental results on a large collection of datasets demonstrate the effectiveness of our algorithms.
[ { "version": "v1", "created": "Wed, 25 Jan 2017 09:32:15 GMT" } ]
2017-01-26T00:00:00
[ [ "Gionis", "Aristides", "" ], [ "Rozenshtein", "Polina", "" ], [ "Tatti", "Nikolaj", "" ], [ "Terzi", "Evimaria", "" ] ]
TITLE: Community-aware network sparsification ABSTRACT: Network sparsification aims to reduce the number of edges of a network while maintaining its structural properties; such properties include shortest paths, cuts, spectral measures, or network modularity. Sparsification has multiple applications, such as, speeding up graph-mining algorithms, graph visualization, as well as identifying the important network edges. In this paper we consider a novel formulation of the network-sparsification problem. In addition to the network, we also consider as input a set of communities. The goal is to sparsify the network so as to preserve the network structure with respect to the given communities. We introduce two variants of the community-aware sparsification problem, leading to sparsifiers that satisfy different connectedness community properties. From the technical point of view, we prove hardness results and devise effective approximation algorithms. Our experimental results on a large collection of datasets demonstrate the effectiveness of our algorithms.
no_new_dataset
0.9434
1701.07266
Kfir Levy Yehuda
Oren Anava, Kfir Y. Levy
k*-Nearest Neighbors: From Global to Local
null
null
null
null
stat.ML cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The weighted k-nearest neighbors algorithm is one of the most fundamental non-parametric methods in pattern recognition and machine learning. The question of setting the optimal number of neighbors as well as the optimal weights has received much attention throughout the years, nevertheless this problem seems to have remained unsettled. In this paper we offer a simple approach to locally weighted regression/classification, where we make the bias-variance tradeoff explicit. Our formulation enables us to phrase a notion of optimal weights, and to efficiently find these weights as well as the optimal number of neighbors efficiently and adaptively, for each data point whose value we wish to estimate. The applicability of our approach is demonstrated on several datasets, showing superior performance over standard locally weighted methods.
[ { "version": "v1", "created": "Wed, 25 Jan 2017 11:18:18 GMT" } ]
2017-01-26T00:00:00
[ [ "Anava", "Oren", "" ], [ "Levy", "Kfir Y.", "" ] ]
TITLE: k*-Nearest Neighbors: From Global to Local ABSTRACT: The weighted k-nearest neighbors algorithm is one of the most fundamental non-parametric methods in pattern recognition and machine learning. The question of setting the optimal number of neighbors as well as the optimal weights has received much attention throughout the years, nevertheless this problem seems to have remained unsettled. In this paper we offer a simple approach to locally weighted regression/classification, where we make the bias-variance tradeoff explicit. Our formulation enables us to phrase a notion of optimal weights, and to efficiently find these weights as well as the optimal number of neighbors efficiently and adaptively, for each data point whose value we wish to estimate. The applicability of our approach is demonstrated on several datasets, showing superior performance over standard locally weighted methods.
no_new_dataset
0.950365
1701.07354
David Villacis
David Villacis, Santeri Kaupinm\"aki, Samuli Siltanen, Teemu Helenius
Photographic dataset: playing cards
9 pages, 12 figures
null
null
null
cs.CV physics.data-an
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This is a photographic dataset collected for testing image processing algorithms. The idea is to have images that can exploit the properties of total variation, therefore a set of playing cards was distributed on the scene. The dataset is made available at www.fips.fi/photographic_dataset2.php
[ { "version": "v1", "created": "Wed, 25 Jan 2017 15:35:09 GMT" } ]
2017-01-26T00:00:00
[ [ "Villacis", "David", "" ], [ "Kaupinmäki", "Santeri", "" ], [ "Siltanen", "Samuli", "" ], [ "Helenius", "Teemu", "" ] ]
TITLE: Photographic dataset: playing cards ABSTRACT: This is a photographic dataset collected for testing image processing algorithms. The idea is to have images that can exploit the properties of total variation, therefore a set of playing cards was distributed on the scene. The dataset is made available at www.fips.fi/photographic_dataset2.php
new_dataset
0.960915
1701.07372
Abdolrahim Kadkhodamohammadi
Abdolrahim Kadkhodamohammadi, Afshin Gangi, Michel de Mathelin, Nicolas Padoy
A Multi-view RGB-D Approach for Human Pose Estimation in Operating Rooms
WACV 2017. Supplementary material video: https://youtu.be/L3A0BzT0FKQ
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Many approaches have been proposed for human pose estimation in single and multi-view RGB images. However, some environments, such as the operating room, are still very challenging for state-of-the-art RGB methods. In this paper, we propose an approach for multi-view 3D human pose estimation from RGB-D images and demonstrate the benefits of using the additional depth channel for pose refinement beyond its use for the generation of improved features. The proposed method permits the joint detection and estimation of the poses without knowing a priori the number of persons present in the scene. We evaluate this approach on a novel multi-view RGB-D dataset acquired during live surgeries and annotated with ground truth 3D poses.
[ { "version": "v1", "created": "Wed, 25 Jan 2017 16:43:41 GMT" } ]
2017-01-26T00:00:00
[ [ "Kadkhodamohammadi", "Abdolrahim", "" ], [ "Gangi", "Afshin", "" ], [ "de Mathelin", "Michel", "" ], [ "Padoy", "Nicolas", "" ] ]
TITLE: A Multi-view RGB-D Approach for Human Pose Estimation in Operating Rooms ABSTRACT: Many approaches have been proposed for human pose estimation in single and multi-view RGB images. However, some environments, such as the operating room, are still very challenging for state-of-the-art RGB methods. In this paper, we propose an approach for multi-view 3D human pose estimation from RGB-D images and demonstrate the benefits of using the additional depth channel for pose refinement beyond its use for the generation of improved features. The proposed method permits the joint detection and estimation of the poses without knowing a priori the number of persons present in the scene. We evaluate this approach on a novel multi-view RGB-D dataset acquired during live surgeries and annotated with ground truth 3D poses.
new_dataset
0.960212
1509.00504
Vijay Gadepally
Vijay Gadepally and Jeremy Kepner
Using a Power Law Distribution to describe Big Data
5 pages
null
10.1109/HPEC.2015.7322459
null
cs.SI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The gap between data production and user ability to access, compute and produce meaningful results calls for tools that address the challenges associated with big data volume, velocity and variety. One of the key hurdles is the inability to methodically remove expected or uninteresting elements from large data sets. This difficulty often wastes valuable researcher and computational time by expending resources on uninteresting parts of data. Social sensors, or sensors which produce data based on human activity, such as Wikipedia, Twitter, and Facebook have an underlying structure which can be thought of as having a Power Law distribution. Such a distribution implies that few nodes generate large amounts of data. In this article, we propose a technique to take an arbitrary dataset and compute a power law distributed background model that bases its parameters on observed statistics. This model can be used to determine the suitability of using a power law or automatically identify high degree nodes for filtering and can be scaled to work with big data.
[ { "version": "v1", "created": "Fri, 28 Aug 2015 22:36:32 GMT" } ]
2017-01-25T00:00:00
[ [ "Gadepally", "Vijay", "" ], [ "Kepner", "Jeremy", "" ] ]
TITLE: Using a Power Law Distribution to describe Big Data ABSTRACT: The gap between data production and user ability to access, compute and produce meaningful results calls for tools that address the challenges associated with big data volume, velocity and variety. One of the key hurdles is the inability to methodically remove expected or uninteresting elements from large data sets. This difficulty often wastes valuable researcher and computational time by expending resources on uninteresting parts of data. Social sensors, or sensors which produce data based on human activity, such as Wikipedia, Twitter, and Facebook have an underlying structure which can be thought of as having a Power Law distribution. Such a distribution implies that few nodes generate large amounts of data. In this article, we propose a technique to take an arbitrary dataset and compute a power law distributed background model that bases its parameters on observed statistics. This model can be used to determine the suitability of using a power law or automatically identify high degree nodes for filtering and can be scaled to work with big data.
no_new_dataset
0.949623
1510.03921
Yongjoo Park
Yongjoo Park, Michael Cafarella, and Barzan Mozafari
Visualization-Aware Sampling for Very Large Databases
null
Data Engineering (ICDE), 2016 IEEE 32nd International Conference on. IEEE, 2016
null
null
cs.DB
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Interactive visualizations are crucial in ad hoc data exploration and analysis. However, with the growing number of massive datasets, generating visualizations in interactive timescales is increasingly challenging. One approach for improving the speed of the visualization tool is via data reduction in order to reduce the computational overhead, but at a potential cost in visualization accuracy. Common data reduction techniques, such as uniform and stratified sampling, do not exploit the fact that the sampled tuples will be transformed into a visualization for human consumption. We propose a visualization-aware sampling (VAS) that guarantees high quality visualizations with a small subset of the entire dataset. We validate our method when applied to scatter and map plots for three common visualization goals: regression, density estimation, and clustering. The key to our sampling method's success is in choosing tuples which minimize a visualization-inspired loss function. Our user study confirms that optimizing this loss function correlates strongly with user success in using the resulting visualizations. We also show the NP-hardness of our optimization problem and propose an efficient approximation algorithm. Our experiments show that, compared to previous methods, (i) using the same sample size, VAS improves user's success by up to 35% in various visualization tasks, and (ii) VAS can achieve a required visualization quality up to 400 times faster.
[ { "version": "v1", "created": "Tue, 13 Oct 2015 22:51:36 GMT" }, { "version": "v2", "created": "Mon, 23 Jan 2017 23:47:49 GMT" } ]
2017-01-25T00:00:00
[ [ "Park", "Yongjoo", "" ], [ "Cafarella", "Michael", "" ], [ "Mozafari", "Barzan", "" ] ]
TITLE: Visualization-Aware Sampling for Very Large Databases ABSTRACT: Interactive visualizations are crucial in ad hoc data exploration and analysis. However, with the growing number of massive datasets, generating visualizations in interactive timescales is increasingly challenging. One approach for improving the speed of the visualization tool is via data reduction in order to reduce the computational overhead, but at a potential cost in visualization accuracy. Common data reduction techniques, such as uniform and stratified sampling, do not exploit the fact that the sampled tuples will be transformed into a visualization for human consumption. We propose a visualization-aware sampling (VAS) that guarantees high quality visualizations with a small subset of the entire dataset. We validate our method when applied to scatter and map plots for three common visualization goals: regression, density estimation, and clustering. The key to our sampling method's success is in choosing tuples which minimize a visualization-inspired loss function. Our user study confirms that optimizing this loss function correlates strongly with user success in using the resulting visualizations. We also show the NP-hardness of our optimization problem and propose an efficient approximation algorithm. Our experiments show that, compared to previous methods, (i) using the same sample size, VAS improves user's success by up to 35% in various visualization tasks, and (ii) VAS can achieve a required visualization quality up to 400 times faster.
no_new_dataset
0.944944
1604.03199
William Gray Roncal
William Gray Roncal, Eva L Dyer, Doga G\"ursoy, Konrad Kording, Narayanan Kasthuri
From sample to knowledge: Towards an integrated approach for neuroscience discovery
first two authors contributed equally. 8 pages, 2 figures. v2: added acknowledgments
null
null
null
q-bio.QM cs.SY q-bio.NC
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Imaging methods used in modern neuroscience experiments are quickly producing large amounts of data capable of providing increasing amounts of knowledge about neuroanatomy and function. A great deal of information in these datasets is relatively unexplored and untapped. One of the bottlenecks in knowledge extraction is that often there is no feedback loop between the knowledge produced (e.g., graph, density estimate, or other statistic) and the earlier stages of the pipeline (e.g., acquisition). We thus advocate for the development of sample-to-knowledge discovery pipelines that one can use to optimize acquisition and processing steps with a particular end goal (i.e., piece of knowledge) in mind. We therefore propose that optimization takes place not just within each processing stage but also between adjacent (and non-adjacent) steps of the pipeline. Furthermore, we explore the existing categories of knowledge representation and models to motivate the types of experiments and analysis needed to achieve the ultimate goal. To illustrate this approach, we provide an experimental paradigm to answer questions about large-scale synaptic distributions through a multimodal approach combining X-ray microtomography and electron microscopy.
[ { "version": "v1", "created": "Tue, 12 Apr 2016 01:41:48 GMT" }, { "version": "v2", "created": "Mon, 23 Jan 2017 19:30:41 GMT" } ]
2017-01-25T00:00:00
[ [ "Roncal", "William Gray", "" ], [ "Dyer", "Eva L", "" ], [ "Gürsoy", "Doga", "" ], [ "Kording", "Konrad", "" ], [ "Kasthuri", "Narayanan", "" ] ]
TITLE: From sample to knowledge: Towards an integrated approach for neuroscience discovery ABSTRACT: Imaging methods used in modern neuroscience experiments are quickly producing large amounts of data capable of providing increasing amounts of knowledge about neuroanatomy and function. A great deal of information in these datasets is relatively unexplored and untapped. One of the bottlenecks in knowledge extraction is that often there is no feedback loop between the knowledge produced (e.g., graph, density estimate, or other statistic) and the earlier stages of the pipeline (e.g., acquisition). We thus advocate for the development of sample-to-knowledge discovery pipelines that one can use to optimize acquisition and processing steps with a particular end goal (i.e., piece of knowledge) in mind. We therefore propose that optimization takes place not just within each processing stage but also between adjacent (and non-adjacent) steps of the pipeline. Furthermore, we explore the existing categories of knowledge representation and models to motivate the types of experiments and analysis needed to achieve the ultimate goal. To illustrate this approach, we provide an experimental paradigm to answer questions about large-scale synaptic distributions through a multimodal approach combining X-ray microtomography and electron microscopy.
no_new_dataset
0.945701
1607.05258
Mohammad Havaei
Mohammad Havaei and Nicolas Guizard and Hugo Larochelle and Pierre-Marc Jodoin
Deep learning trends for focal brain pathology segmentation in MRI
Published in Machine Learning for Health Informatics
null
10.1007/978-3-319-50478-0_6
null
cs.CV
http://creativecommons.org/licenses/by-nc-sa/4.0/
Segmentation of focal (localized) brain pathologies such as brain tumors and brain lesions caused by multiple sclerosis and ischemic strokes are necessary for medical diagnosis, surgical planning and disease development as well as other applications such as tractography. Over the years, attempts have been made to automate this process for both clinical and research reasons. In this regard, machine learning methods have long been a focus of attention. Over the past two years, the medical imaging field has seen a rise in the use of a particular branch of machine learning commonly known as deep learning. In the non-medical computer vision world, deep learning based methods have obtained state-of-the-art results on many datasets. Recent studies in computer aided diagnostics have shown deep learning methods (and especially convolutional neural networks - CNN) to yield promising results. In this chapter, we provide a survey of CNN methods applied to medical imaging with a focus on brain pathology segmentation. In particular, we discuss their characteristic peculiarities and their specific configuration and adjustments that are best suited to segment medical images. We also underline the intrinsic differences deep learning methods have with other machine learning methods.
[ { "version": "v1", "created": "Mon, 18 Jul 2016 19:52:00 GMT" }, { "version": "v2", "created": "Mon, 23 Jan 2017 16:41:46 GMT" }, { "version": "v3", "created": "Tue, 24 Jan 2017 02:44:48 GMT" } ]
2017-01-25T00:00:00
[ [ "Havaei", "Mohammad", "" ], [ "Guizard", "Nicolas", "" ], [ "Larochelle", "Hugo", "" ], [ "Jodoin", "Pierre-Marc", "" ] ]
TITLE: Deep learning trends for focal brain pathology segmentation in MRI ABSTRACT: Segmentation of focal (localized) brain pathologies such as brain tumors and brain lesions caused by multiple sclerosis and ischemic strokes are necessary for medical diagnosis, surgical planning and disease development as well as other applications such as tractography. Over the years, attempts have been made to automate this process for both clinical and research reasons. In this regard, machine learning methods have long been a focus of attention. Over the past two years, the medical imaging field has seen a rise in the use of a particular branch of machine learning commonly known as deep learning. In the non-medical computer vision world, deep learning based methods have obtained state-of-the-art results on many datasets. Recent studies in computer aided diagnostics have shown deep learning methods (and especially convolutional neural networks - CNN) to yield promising results. In this chapter, we provide a survey of CNN methods applied to medical imaging with a focus on brain pathology segmentation. In particular, we discuss their characteristic peculiarities and their specific configuration and adjustments that are best suited to segment medical images. We also underline the intrinsic differences deep learning methods have with other machine learning methods.
no_new_dataset
0.946547
1701.06643
Sergey Korolev
Sergey Korolev, Amir Safiullin, Mikhail Belyaev, Yulia Dodonova
Residual and Plain Convolutional Neural Networks for 3D Brain MRI Classification
IEEE International Symposium on Biomedical Imaging 2017
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the recent years there have been a number of studies that applied deep learning algorithms to neuroimaging data. Pipelines used in those studies mostly require multiple processing steps for feature extraction, although modern advancements in deep learning for image classification can provide a powerful framework for automatic feature generation and more straightforward analysis. In this paper, we show how similar performance can be achieved skipping these feature extraction steps with the residual and plain 3D convolutional neural network architectures. We demonstrate the performance of the proposed approach for classification of Alzheimer's disease versus mild cognitive impairment and normal controls on the Alzheimer's Disease National Initiative (ADNI) dataset of 3D structural MRI brain scans.
[ { "version": "v1", "created": "Mon, 23 Jan 2017 21:54:50 GMT" } ]
2017-01-25T00:00:00
[ [ "Korolev", "Sergey", "" ], [ "Safiullin", "Amir", "" ], [ "Belyaev", "Mikhail", "" ], [ "Dodonova", "Yulia", "" ] ]
TITLE: Residual and Plain Convolutional Neural Networks for 3D Brain MRI Classification ABSTRACT: In the recent years there have been a number of studies that applied deep learning algorithms to neuroimaging data. Pipelines used in those studies mostly require multiple processing steps for feature extraction, although modern advancements in deep learning for image classification can provide a powerful framework for automatic feature generation and more straightforward analysis. In this paper, we show how similar performance can be achieved skipping these feature extraction steps with the residual and plain 3D convolutional neural network architectures. We demonstrate the performance of the proposed approach for classification of Alzheimer's disease versus mild cognitive impairment and normal controls on the Alzheimer's Disease National Initiative (ADNI) dataset of 3D structural MRI brain scans.
no_new_dataset
0.949716
1701.06659
Cheng-Yang Fu
Cheng-Yang Fu, Wei Liu, Ananth Ranga, Ambrish Tyagi, Alexander C. Berg
DSSD : Deconvolutional Single Shot Detector
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The main contribution of this paper is an approach for introducing additional context into state-of-the-art general object detection. To achieve this we first combine a state-of-the-art classifier (Residual-101[14]) with a fast detection framework (SSD[18]). We then augment SSD+Residual-101 with deconvolution layers to introduce additional large-scale context in object detection and improve accuracy, especially for small objects, calling our resulting system DSSD for deconvolutional single shot detector. While these two contributions are easily described at a high-level, a naive implementation does not succeed. Instead we show that carefully adding additional stages of learned transformations, specifically a module for feed-forward connections in deconvolution and a new output module, enables this new approach and forms a potential way forward for further detection research. Results are shown on both PASCAL VOC and COCO detection. Our DSSD with $513 \times 513$ input achieves 81.5% mAP on VOC2007 test, 80.0% mAP on VOC2012 test, and 33.2% mAP on COCO, outperforming a state-of-the-art method R-FCN[3] on each dataset.
[ { "version": "v1", "created": "Mon, 23 Jan 2017 22:33:35 GMT" } ]
2017-01-25T00:00:00
[ [ "Fu", "Cheng-Yang", "" ], [ "Liu", "Wei", "" ], [ "Ranga", "Ananth", "" ], [ "Tyagi", "Ambrish", "" ], [ "Berg", "Alexander C.", "" ] ]
TITLE: DSSD : Deconvolutional Single Shot Detector ABSTRACT: The main contribution of this paper is an approach for introducing additional context into state-of-the-art general object detection. To achieve this we first combine a state-of-the-art classifier (Residual-101[14]) with a fast detection framework (SSD[18]). We then augment SSD+Residual-101 with deconvolution layers to introduce additional large-scale context in object detection and improve accuracy, especially for small objects, calling our resulting system DSSD for deconvolutional single shot detector. While these two contributions are easily described at a high-level, a naive implementation does not succeed. Instead we show that carefully adding additional stages of learned transformations, specifically a module for feed-forward connections in deconvolution and a new output module, enables this new approach and forms a potential way forward for further detection research. Results are shown on both PASCAL VOC and COCO detection. Our DSSD with $513 \times 513$ input achieves 81.5% mAP on VOC2007 test, 80.0% mAP on VOC2012 test, and 33.2% mAP on COCO, outperforming a state-of-the-art method R-FCN[3] on each dataset.
no_new_dataset
0.947624
1701.06715
Xiaohao Cai
Juheon Lee, David Coomes, Carola-Bibiane Schonlieb, Xiaohao Cai, Jan Lellmann, Michele Dalponte, Yadvinder Malhi, Nathalie Butt, Mike Morecroft
A graph cut approach to 3D tree delineation, using integrated airborne LiDAR and hyperspectral imagery
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recognising individual trees within remotely sensed imagery has important applications in forest ecology and management. Several algorithms for tree delineation have been suggested, mostly based on locating local maxima or inverted basins in raster canopy height models (CHMs) derived from Light Detection And Ranging (LiDAR) data or photographs. However, these algorithms often lead to inaccurate estimates of forest stand characteristics due to the limited information content of raster CHMs. Here we develop a 3D tree delineation method which uses graph cut to delineate trees from the full 3D LiDAR point cloud, and also makes use of any optical imagery available (hyperspectral imagery in our case). First, conventional methods are used to locate local maxima in the CHM and generate an initial map of trees. Second, a graph is built from the LiDAR point cloud, fused with the hyperspectral data. For computational efficiency, the feature space of hyperspectral imagery is reduced using robust PCA. Third, a multi-class normalised cut is applied to the graph, using the initial map of trees to constrain the number of clusters and their locations. Finally, recursive normalised cut is used to subdivide, if necessary, each of the clusters identified by the initial analysis. We call this approach Multiclass Cut followed by Recursive Cut (MCRC). The effectiveness of MCRC was tested using three datasets: i) NewFor, ii) a coniferous forest in the Italian Alps, and iii) a deciduous woodland in the UK. The performance of MCRC was usually superior to that of other delineation methods, and was further improved by including high-resolution optical imagery. Since MCRC delineates the entire LiDAR point cloud in 3D, it allows individual crown characteristics to be measured. By making full use of the data available, graph cut has the potential to considerably improve the accuracy of tree delineation.
[ { "version": "v1", "created": "Tue, 24 Jan 2017 02:41:30 GMT" } ]
2017-01-25T00:00:00
[ [ "Lee", "Juheon", "" ], [ "Coomes", "David", "" ], [ "Schonlieb", "Carola-Bibiane", "" ], [ "Cai", "Xiaohao", "" ], [ "Lellmann", "Jan", "" ], [ "Dalponte", "Michele", "" ], [ "Malhi", "Yadvinder", "" ], [ "Butt", "Nathalie", "" ], [ "Morecroft", "Mike", "" ] ]
TITLE: A graph cut approach to 3D tree delineation, using integrated airborne LiDAR and hyperspectral imagery ABSTRACT: Recognising individual trees within remotely sensed imagery has important applications in forest ecology and management. Several algorithms for tree delineation have been suggested, mostly based on locating local maxima or inverted basins in raster canopy height models (CHMs) derived from Light Detection And Ranging (LiDAR) data or photographs. However, these algorithms often lead to inaccurate estimates of forest stand characteristics due to the limited information content of raster CHMs. Here we develop a 3D tree delineation method which uses graph cut to delineate trees from the full 3D LiDAR point cloud, and also makes use of any optical imagery available (hyperspectral imagery in our case). First, conventional methods are used to locate local maxima in the CHM and generate an initial map of trees. Second, a graph is built from the LiDAR point cloud, fused with the hyperspectral data. For computational efficiency, the feature space of hyperspectral imagery is reduced using robust PCA. Third, a multi-class normalised cut is applied to the graph, using the initial map of trees to constrain the number of clusters and their locations. Finally, recursive normalised cut is used to subdivide, if necessary, each of the clusters identified by the initial analysis. We call this approach Multiclass Cut followed by Recursive Cut (MCRC). The effectiveness of MCRC was tested using three datasets: i) NewFor, ii) a coniferous forest in the Italian Alps, and iii) a deciduous woodland in the UK. The performance of MCRC was usually superior to that of other delineation methods, and was further improved by including high-resolution optical imagery. Since MCRC delineates the entire LiDAR point cloud in 3D, it allows individual crown characteristics to be measured. By making full use of the data available, graph cut has the potential to considerably improve the accuracy of tree delineation.
no_new_dataset
0.950549
1701.06751
Qiongkai Xu
Qiongkai Xu, Qing Wang, Chenchen Xu and Lizhen Qu
Collective Vertex Classification Using Recursive Neural Network
7 pages, 5 figures
null
null
null
cs.LG cs.SI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Collective classification of vertices is a task of assigning categories to each vertex in a graph based on both vertex attributes and link structure. Nevertheless, some existing approaches do not use the features of neighbouring vertices properly, due to the noise introduced by these features. In this paper, we propose a graph-based recursive neural network framework for collective vertex classification. In this framework, we generate hidden representations from both attributes of vertices and representations of neighbouring vertices via recursive neural networks. Under this framework, we explore two types of recursive neural units, naive recursive neural unit and long short-term memory unit. We have conducted experiments on four real-world network datasets. The experimental results show that our frame- work with long short-term memory model achieves better results and outperforms several competitive baseline methods.
[ { "version": "v1", "created": "Tue, 24 Jan 2017 07:07:15 GMT" } ]
2017-01-25T00:00:00
[ [ "Xu", "Qiongkai", "" ], [ "Wang", "Qing", "" ], [ "Xu", "Chenchen", "" ], [ "Qu", "Lizhen", "" ] ]
TITLE: Collective Vertex Classification Using Recursive Neural Network ABSTRACT: Collective classification of vertices is a task of assigning categories to each vertex in a graph based on both vertex attributes and link structure. Nevertheless, some existing approaches do not use the features of neighbouring vertices properly, due to the noise introduced by these features. In this paper, we propose a graph-based recursive neural network framework for collective vertex classification. In this framework, we generate hidden representations from both attributes of vertices and representations of neighbouring vertices via recursive neural networks. Under this framework, we explore two types of recursive neural units, naive recursive neural unit and long short-term memory unit. We have conducted experiments on four real-world network datasets. The experimental results show that our frame- work with long short-term memory model achieves better results and outperforms several competitive baseline methods.
no_new_dataset
0.951729
1701.06861
Panagiotis Papapetrou
Hend Kareem, Lars Asker, and Panagiotis Papapetrou
Detecting Hierarchical Ties Using Link-Analysis Ranking at Different Levels of Time Granularity
null
null
null
null
cs.SI physics.soc-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Social networks contain implicit knowledge that can be used to infer hierarchical relations that are not explicitly present in the available data. Interaction patterns are typically affected by users' social relations. We present an approach to inferring such information that applies a link-analysis ranking algorithm at different levels of time granularity. In addition, a voting scheme is employed for obtaining the hierarchical relations. The approach is evaluated on two datasets: the Enron email data set, where the goal is to infer manager-subordinate relationships, and the Co-author data set, where the goal is to infer PhD advisor-advisee relations. The experimental results indicate that the proposed approach outperforms more traditional approaches to inferring hierarchical relations from social networks.
[ { "version": "v1", "created": "Tue, 24 Jan 2017 13:23:40 GMT" } ]
2017-01-25T00:00:00
[ [ "Kareem", "Hend", "" ], [ "Asker", "Lars", "" ], [ "Papapetrou", "Panagiotis", "" ] ]
TITLE: Detecting Hierarchical Ties Using Link-Analysis Ranking at Different Levels of Time Granularity ABSTRACT: Social networks contain implicit knowledge that can be used to infer hierarchical relations that are not explicitly present in the available data. Interaction patterns are typically affected by users' social relations. We present an approach to inferring such information that applies a link-analysis ranking algorithm at different levels of time granularity. In addition, a voting scheme is employed for obtaining the hierarchical relations. The approach is evaluated on two datasets: the Enron email data set, where the goal is to infer manager-subordinate relationships, and the Co-author data set, where the goal is to infer PhD advisor-advisee relations. The experimental results indicate that the proposed approach outperforms more traditional approaches to inferring hierarchical relations from social networks.
no_new_dataset
0.948298
1701.06944
Michael Ying Yang
Michael Ying Yang, Hanno Ackermann, Weiyao Lin, Sitong Feng, Bodo Rosenhahn
Motion Segmentation via Global and Local Sparse Subspace Optimization
11 pages
null
null
null
cs.CV
http://creativecommons.org/licenses/by/4.0/
In this paper, we propose a new framework for segmenting feature-based moving objects under affine subspace model. Since the feature trajectories in practice are high-dimensional and contain a lot of noise, we firstly apply the sparse PCA to represent the original trajectories with a low-dimensional global subspace, which consists of the orthogonal sparse principal vectors. Subsequently, the local subspace separation will be achieved via automatically searching the sparse representation of the nearest neighbors for each projected data. In order to refine the local subspace estimation result and deal with the missing data problem, we propose an error estimation to encourage the projected data that span a same local subspace to be clustered together. In the end, the segmentation of different motions is achieved through the spectral clustering on an affinity matrix, which is constructed with both the error estimation and sparse neighbors optimization. We test our method extensively and compare it with state-of-the-art methods on the Hopkins 155 dataset and Freiburg-Berkeley Motion Segmentation dataset. The results show that our method is comparable with the other motion segmentation methods, and in many cases exceed them in terms of precision and computation time.
[ { "version": "v1", "created": "Tue, 24 Jan 2017 15:49:53 GMT" } ]
2017-01-25T00:00:00
[ [ "Yang", "Michael Ying", "" ], [ "Ackermann", "Hanno", "" ], [ "Lin", "Weiyao", "" ], [ "Feng", "Sitong", "" ], [ "Rosenhahn", "Bodo", "" ] ]
TITLE: Motion Segmentation via Global and Local Sparse Subspace Optimization ABSTRACT: In this paper, we propose a new framework for segmenting feature-based moving objects under affine subspace model. Since the feature trajectories in practice are high-dimensional and contain a lot of noise, we firstly apply the sparse PCA to represent the original trajectories with a low-dimensional global subspace, which consists of the orthogonal sparse principal vectors. Subsequently, the local subspace separation will be achieved via automatically searching the sparse representation of the nearest neighbors for each projected data. In order to refine the local subspace estimation result and deal with the missing data problem, we propose an error estimation to encourage the projected data that span a same local subspace to be clustered together. In the end, the segmentation of different motions is achieved through the spectral clustering on an affinity matrix, which is constructed with both the error estimation and sparse neighbors optimization. We test our method extensively and compare it with state-of-the-art methods on the Hopkins 155 dataset and Freiburg-Berkeley Motion Segmentation dataset. The results show that our method is comparable with the other motion segmentation methods, and in many cases exceed them in terms of precision and computation time.
no_new_dataset
0.948585
1507.04576
Maedeh Aghaei
Maedeh Aghaei and Mariella Dimiccoli and Petia Radeva
Multi-Face Tracking by Extended Bag-of-Tracklets in Egocentric Videos
27 pages, 18 figures, submitted to computer vision and image understanding journal
null
10.1016/j.cviu.2016.02.013
YCVIU2393
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Wearable cameras offer a hands-free way to record egocentric images of daily experiences, where social events are of special interest. The first step towards detection of social events is to track the appearance of multiple persons involved in it. In this paper, we propose a novel method to find correspondences of multiple faces in low temporal resolution egocentric videos acquired through a wearable camera. This kind of photo-stream imposes additional challenges to the multi-tracking problem with respect to conventional videos. Due to the free motion of the camera and to its low temporal resolution, abrupt changes in the field of view, in illumination condition and in the target location are highly frequent. To overcome such difficulties, we propose a multi-face tracking method that generates a set of tracklets through finding correspondences along the whole sequence for each detected face and takes advantage of the tracklets redundancy to deal with unreliable ones. Similar tracklets are grouped into the so called extended bag-of-tracklets (eBoT), which is aimed to correspond to a specific person. Finally, a prototype tracklet is extracted for each eBoT, where the occurred occlusions are estimated by relying on a new measure of confidence. We validated our approach over an extensive dataset of egocentric photo-streams and compared it to state of the art methods, demonstrating its effectiveness and robustness.
[ { "version": "v1", "created": "Thu, 16 Jul 2015 13:51:47 GMT" }, { "version": "v2", "created": "Wed, 13 Jan 2016 12:26:09 GMT" } ]
2017-01-24T00:00:00
[ [ "Aghaei", "Maedeh", "" ], [ "Dimiccoli", "Mariella", "" ], [ "Radeva", "Petia", "" ] ]
TITLE: Multi-Face Tracking by Extended Bag-of-Tracklets in Egocentric Videos ABSTRACT: Wearable cameras offer a hands-free way to record egocentric images of daily experiences, where social events are of special interest. The first step towards detection of social events is to track the appearance of multiple persons involved in it. In this paper, we propose a novel method to find correspondences of multiple faces in low temporal resolution egocentric videos acquired through a wearable camera. This kind of photo-stream imposes additional challenges to the multi-tracking problem with respect to conventional videos. Due to the free motion of the camera and to its low temporal resolution, abrupt changes in the field of view, in illumination condition and in the target location are highly frequent. To overcome such difficulties, we propose a multi-face tracking method that generates a set of tracklets through finding correspondences along the whole sequence for each detected face and takes advantage of the tracklets redundancy to deal with unreliable ones. Similar tracklets are grouped into the so called extended bag-of-tracklets (eBoT), which is aimed to correspond to a specific person. Finally, a prototype tracklet is extracted for each eBoT, where the occurred occlusions are estimated by relying on a new measure of confidence. We validated our approach over an extensive dataset of egocentric photo-streams and compared it to state of the art methods, demonstrating its effectiveness and robustness.
no_new_dataset
0.923247
1605.05590
Matteo Ceccarello
Matteo Ceccarello, Andrea Pietracaprina, Geppino Pucci, Eli Upfal
MapReduce and Streaming Algorithms for Diversity Maximization in Metric Spaces of Bounded Doubling Dimension
Extended version of http://www.vldb.org/pvldb/vol10/p469-ceccarello.pdf, PVLDB Volume 10, No. 5, January 2017
null
null
null
cs.DC
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Given a dataset of points in a metric space and an integer $k$, a diversity maximization problem requires determining a subset of $k$ points maximizing some diversity objective measure, e.g., the minimum or the average distance between two points in the subset. Diversity maximization is computationally hard, hence only approximate solutions can be hoped for. Although its applications are mainly in massive data analysis, most of the past research on diversity maximization focused on the sequential setting. In this work we present space and pass/round-efficient diversity maximization algorithms for the Streaming and MapReduce models and analyze their approximation guarantees for the relevant class of metric spaces of bounded doubling dimension. Like other approaches in the literature, our algorithms rely on the determination of high-quality core-sets, i.e., (much) smaller subsets of the input which contain good approximations to the optimal solution for the whole input. For a variety of diversity objective functions, our algorithms attain an $(\alpha+\epsilon)$-approximation ratio, for any constant $\epsilon>0$, where $\alpha$ is the best approximation ratio achieved by a polynomial-time, linear-space sequential algorithm for the same diversity objective. This improves substantially over the approximation ratios attainable in Streaming and MapReduce by state-of-the-art algorithms for general metric spaces. We provide extensive experimental evidence of the effectiveness of our algorithms on both real world and synthetic datasets, scaling up to over a billion points.
[ { "version": "v1", "created": "Wed, 18 May 2016 14:11:31 GMT" }, { "version": "v2", "created": "Mon, 20 Jun 2016 12:55:52 GMT" }, { "version": "v3", "created": "Sun, 16 Oct 2016 13:04:51 GMT" }, { "version": "v4", "created": "Mon, 23 Jan 2017 16:10:19 GMT" } ]
2017-01-24T00:00:00
[ [ "Ceccarello", "Matteo", "" ], [ "Pietracaprina", "Andrea", "" ], [ "Pucci", "Geppino", "" ], [ "Upfal", "Eli", "" ] ]
TITLE: MapReduce and Streaming Algorithms for Diversity Maximization in Metric Spaces of Bounded Doubling Dimension ABSTRACT: Given a dataset of points in a metric space and an integer $k$, a diversity maximization problem requires determining a subset of $k$ points maximizing some diversity objective measure, e.g., the minimum or the average distance between two points in the subset. Diversity maximization is computationally hard, hence only approximate solutions can be hoped for. Although its applications are mainly in massive data analysis, most of the past research on diversity maximization focused on the sequential setting. In this work we present space and pass/round-efficient diversity maximization algorithms for the Streaming and MapReduce models and analyze their approximation guarantees for the relevant class of metric spaces of bounded doubling dimension. Like other approaches in the literature, our algorithms rely on the determination of high-quality core-sets, i.e., (much) smaller subsets of the input which contain good approximations to the optimal solution for the whole input. For a variety of diversity objective functions, our algorithms attain an $(\alpha+\epsilon)$-approximation ratio, for any constant $\epsilon>0$, where $\alpha$ is the best approximation ratio achieved by a polynomial-time, linear-space sequential algorithm for the same diversity objective. This improves substantially over the approximation ratios attainable in Streaming and MapReduce by state-of-the-art algorithms for general metric spaces. We provide extensive experimental evidence of the effectiveness of our algorithms on both real world and synthetic datasets, scaling up to over a billion points.
no_new_dataset
0.947962
1605.06276
Alexander Gorban
A.N. Gorban, E.M. Mirkes, A. Zinovyev
Piece-wise quadratic approximations of arbitrary error functions for fast and robust machine learning
Edited and extended version with algortihms of regularized regression
Neural Networks, Volume 84, December 2016, 28-38
10.1016/j.neunet.2016.08.007
null
cs.LG stat.ML
http://creativecommons.org/licenses/by/4.0/
Most of machine learning approaches have stemmed from the application of minimizing the mean squared distance principle, based on the computationally efficient quadratic optimization methods. However, when faced with high-dimensional and noisy data, the quadratic error functionals demonstrated many weaknesses including high sensitivity to contaminating factors and dimensionality curse. Therefore, a lot of recent applications in machine learning exploited properties of non-quadratic error functionals based on $L_1$ norm or even sub-linear potentials corresponding to quasinorms $L_p$ ($0<p<1$). The back side of these approaches is increase in computational cost for optimization. Till so far, no approaches have been suggested to deal with {\it arbitrary} error functionals, in a flexible and computationally efficient framework. In this paper, we develop a theory and basic universal data approximation algorithms ($k$-means, principal components, principal manifolds and graphs, regularized and sparse regression), based on piece-wise quadratic error potentials of subquadratic growth (PQSQ potentials). We develop a new and universal framework to minimize {\it arbitrary sub-quadratic error potentials} using an algorithm with guaranteed fast convergence to the local or global error minimum. The theory of PQSQ potentials is based on the notion of the cone of minorant functions, and represents a natural approximation formalism based on the application of min-plus algebra. The approach can be applied in most of existing machine learning methods, including methods of data approximation and regularized and sparse regression, leading to the improvement in the computational cost/accuracy trade-off. We demonstrate that on synthetic and real-life datasets PQSQ-based machine learning methods achieve orders of magnitude faster computational performance than the corresponding state-of-the-art methods.
[ { "version": "v1", "created": "Fri, 20 May 2016 10:25:47 GMT" }, { "version": "v2", "created": "Sun, 21 Aug 2016 12:44:25 GMT" } ]
2017-01-24T00:00:00
[ [ "Gorban", "A. N.", "" ], [ "Mirkes", "E. M.", "" ], [ "Zinovyev", "A.", "" ] ]
TITLE: Piece-wise quadratic approximations of arbitrary error functions for fast and robust machine learning ABSTRACT: Most of machine learning approaches have stemmed from the application of minimizing the mean squared distance principle, based on the computationally efficient quadratic optimization methods. However, when faced with high-dimensional and noisy data, the quadratic error functionals demonstrated many weaknesses including high sensitivity to contaminating factors and dimensionality curse. Therefore, a lot of recent applications in machine learning exploited properties of non-quadratic error functionals based on $L_1$ norm or even sub-linear potentials corresponding to quasinorms $L_p$ ($0<p<1$). The back side of these approaches is increase in computational cost for optimization. Till so far, no approaches have been suggested to deal with {\it arbitrary} error functionals, in a flexible and computationally efficient framework. In this paper, we develop a theory and basic universal data approximation algorithms ($k$-means, principal components, principal manifolds and graphs, regularized and sparse regression), based on piece-wise quadratic error potentials of subquadratic growth (PQSQ potentials). We develop a new and universal framework to minimize {\it arbitrary sub-quadratic error potentials} using an algorithm with guaranteed fast convergence to the local or global error minimum. The theory of PQSQ potentials is based on the notion of the cone of minorant functions, and represents a natural approximation formalism based on the application of min-plus algebra. The approach can be applied in most of existing machine learning methods, including methods of data approximation and regularized and sparse regression, leading to the improvement in the computational cost/accuracy trade-off. We demonstrate that on synthetic and real-life datasets PQSQ-based machine learning methods achieve orders of magnitude faster computational performance than the corresponding state-of-the-art methods.
no_new_dataset
0.946498
1607.05836
Jiaping Zhao
Jiaping Zhao and Laurent Itti
Improved Deep Learning of Object Category using Pose Information
10 pages, accepted by WACV 2017
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Despite significant recent progress, the best available computer vision algorithms still lag far behind human capabilities, even for recognizing individual discrete objects under various poses, illuminations, and backgrounds. Here we present a new approach to using object pose information to improve deep network learning. While existing large-scale datasets, e.g. ImageNet, do not have pose information, we leverage the newly published turntable dataset, iLab-20M, which has ~22M images of 704 object instances shot under different lightings, camera viewpoints and turntable rotations, to do more controlled object recognition experiments. We introduce a new convolutional neural network architecture, what/where CNN (2W-CNN), built on a linear-chain feedforward CNN (e.g., AlexNet), augmented by hierarchical layers regularized by object poses. Pose information is only used as feedback signal during training, in addition to category information; during test, the feedforward network only predicts category. To validate the approach, we train both 2W-CNN and AlexNet using a fraction of the dataset, and 2W-CNN achieves 6% performance improvement in category prediction. We show mathematically that 2W-CNN has inherent advantages over AlexNet under the stochastic gradient descent (SGD) optimization procedure. Further more, we fine-tune object recognition on ImageNet by using the pretrained 2W-CNN and AlexNet features on iLab-20M, results show that significant improvements have been achieved, compared with training AlexNet from scratch. Moreover, fine-tuning 2W-CNN features performs even better than fine-tuning the pretrained AlexNet features. These results show pretrained features on iLab- 20M generalizes well to natural image datasets, and 2WCNN learns even better features for object recognition than AlexNet.
[ { "version": "v1", "created": "Wed, 20 Jul 2016 07:11:08 GMT" }, { "version": "v2", "created": "Wed, 31 Aug 2016 19:07:10 GMT" }, { "version": "v3", "created": "Sun, 22 Jan 2017 23:53:15 GMT" } ]
2017-01-24T00:00:00
[ [ "Zhao", "Jiaping", "" ], [ "Itti", "Laurent", "" ] ]
TITLE: Improved Deep Learning of Object Category using Pose Information ABSTRACT: Despite significant recent progress, the best available computer vision algorithms still lag far behind human capabilities, even for recognizing individual discrete objects under various poses, illuminations, and backgrounds. Here we present a new approach to using object pose information to improve deep network learning. While existing large-scale datasets, e.g. ImageNet, do not have pose information, we leverage the newly published turntable dataset, iLab-20M, which has ~22M images of 704 object instances shot under different lightings, camera viewpoints and turntable rotations, to do more controlled object recognition experiments. We introduce a new convolutional neural network architecture, what/where CNN (2W-CNN), built on a linear-chain feedforward CNN (e.g., AlexNet), augmented by hierarchical layers regularized by object poses. Pose information is only used as feedback signal during training, in addition to category information; during test, the feedforward network only predicts category. To validate the approach, we train both 2W-CNN and AlexNet using a fraction of the dataset, and 2W-CNN achieves 6% performance improvement in category prediction. We show mathematically that 2W-CNN has inherent advantages over AlexNet under the stochastic gradient descent (SGD) optimization procedure. Further more, we fine-tune object recognition on ImageNet by using the pretrained 2W-CNN and AlexNet features on iLab-20M, results show that significant improvements have been achieved, compared with training AlexNet from scratch. Moreover, fine-tuning 2W-CNN features performs even better than fine-tuning the pretrained AlexNet features. These results show pretrained features on iLab- 20M generalizes well to natural image datasets, and 2WCNN learns even better features for object recognition than AlexNet.
no_new_dataset
0.946597
1607.05851
Jiaping Zhao
Jiaping Zhao, Chin-kai Chang and Laurent Itti
Learning to Recognize Objects by Retaining other Factors of Variation
9 pages, accepted by WACV 2017
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Natural images are generated under many factors, including shape, pose, illumination etc. Most existing ConvNets formulate object recognition from natural images as a single task classification problem, and attempt to learn features useful for object categories, but invariant to other factors of variation as much as possible. These architectures do not explicitly learn other factors, like pose and lighting, instead, they usually discard them by pooling and normalization. In this work, we take the opposite approach: we train ConvNets for object recognition by retaining other factors (pose in our case) and learn them jointly with object category. We design a new multi-task leaning (MTL) ConvNet, named disentangling CNN (disCNN), which explicitly enforces the disentangled representations of object identity and pose, and is trained to predict object categories and pose transformations. We show that disCNN achieves significantly better object recognition accuracies than AlexNet trained solely to predict object categories on the iLab-20M dataset, which is a large scale turntable dataset with detailed object pose and lighting information. We further show that the pretrained disCNN/AlexNet features on iLab- 20M generalize to object recognition on both Washington RGB-D and ImageNet datasets, and the pretrained disCNN features are significantly better than the pretrained AlexNet features for fine-tuning object recognition on the ImageNet dataset.
[ { "version": "v1", "created": "Wed, 20 Jul 2016 07:58:57 GMT" }, { "version": "v2", "created": "Wed, 31 Aug 2016 19:05:35 GMT" }, { "version": "v3", "created": "Sun, 22 Jan 2017 23:56:42 GMT" } ]
2017-01-24T00:00:00
[ [ "Zhao", "Jiaping", "" ], [ "Chang", "Chin-kai", "" ], [ "Itti", "Laurent", "" ] ]
TITLE: Learning to Recognize Objects by Retaining other Factors of Variation ABSTRACT: Natural images are generated under many factors, including shape, pose, illumination etc. Most existing ConvNets formulate object recognition from natural images as a single task classification problem, and attempt to learn features useful for object categories, but invariant to other factors of variation as much as possible. These architectures do not explicitly learn other factors, like pose and lighting, instead, they usually discard them by pooling and normalization. In this work, we take the opposite approach: we train ConvNets for object recognition by retaining other factors (pose in our case) and learn them jointly with object category. We design a new multi-task leaning (MTL) ConvNet, named disentangling CNN (disCNN), which explicitly enforces the disentangled representations of object identity and pose, and is trained to predict object categories and pose transformations. We show that disCNN achieves significantly better object recognition accuracies than AlexNet trained solely to predict object categories on the iLab-20M dataset, which is a large scale turntable dataset with detailed object pose and lighting information. We further show that the pretrained disCNN/AlexNet features on iLab- 20M generalize to object recognition on both Washington RGB-D and ImageNet datasets, and the pretrained disCNN features are significantly better than the pretrained AlexNet features for fine-tuning object recognition on the ImageNet dataset.
no_new_dataset
0.948822
1609.00085
Rajasekar Venkatesan
Rajasekar Venkatesan, Meng Joo Er
A Novel Progressive Learning Technique for Multi-class Classification
23 pages, 13 tables, 11 figures
null
null
null
cs.LG cs.AI cs.NE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, a progressive learning technique for multi-class classification is proposed. This newly developed learning technique is independent of the number of class constraints and it can learn new classes while still retaining the knowledge of previous classes. Whenever a new class (non-native to the knowledge learnt thus far) is encountered, the neural network structure gets remodeled automatically by facilitating new neurons and interconnections, and the parameters are calculated in such a way that it retains the knowledge learnt thus far. This technique is suitable for real-world applications where the number of classes is often unknown and online learning from real-time data is required. The consistency and the complexity of the progressive learning technique are analyzed. Several standard datasets are used to evaluate the performance of the developed technique. A comparative study shows that the developed technique is superior.
[ { "version": "v1", "created": "Thu, 1 Sep 2016 01:50:18 GMT" }, { "version": "v2", "created": "Sun, 22 Jan 2017 09:52:06 GMT" } ]
2017-01-24T00:00:00
[ [ "Venkatesan", "Rajasekar", "" ], [ "Er", "Meng Joo", "" ] ]
TITLE: A Novel Progressive Learning Technique for Multi-class Classification ABSTRACT: In this paper, a progressive learning technique for multi-class classification is proposed. This newly developed learning technique is independent of the number of class constraints and it can learn new classes while still retaining the knowledge of previous classes. Whenever a new class (non-native to the knowledge learnt thus far) is encountered, the neural network structure gets remodeled automatically by facilitating new neurons and interconnections, and the parameters are calculated in such a way that it retains the knowledge learnt thus far. This technique is suitable for real-world applications where the number of classes is often unknown and online learning from real-time data is required. The consistency and the complexity of the progressive learning technique are analyzed. Several standard datasets are used to evaluate the performance of the developed technique. A comparative study shows that the developed technique is superior.
no_new_dataset
0.948632
1611.08749
Randall Balestriero
Herve Glotin, Julien Ricard, Randall Balestriero
Fast Chirplet Transform to Enhance CNN Machine Listening - Validation on Animal calls and Speech
null
null
null
null
cs.SD
http://creativecommons.org/licenses/by-nc-sa/4.0/
The scattering framework offers an optimal hierarchical convolutional decomposition according to its kernels. Convolutional Neural Net (CNN) can be seen as an optimal kernel decomposition, nevertheless it requires large amount of training data to learn its kernels. We propose a trade-off between these two approaches: a Chirplet kernel as an efficient Q constant bioacoustic representation to pretrain CNN. First we motivate Chirplet bioinspired auditory representation. Second we give the first algorithm (and code) of a Fast Chirplet Transform (FCT). Third, we demonstrate the computation efficiency of FCT on large environmental data base: months of Orca recordings, and 1000 Birds species from the LifeClef challenge. Fourth, we validate FCT on the vowels subset of the Speech TIMIT dataset. The results show that FCT accelerates CNN when it pretrains low level layers: it reduces training duration by -28\% for birds classification, and by -26% for vowels classification. Scores are also enhanced by FCT pretraining, with a relative gain of +7.8% of Mean Average Precision on birds, and +2.3\% of vowel accuracy against raw audio CNN. We conclude on perspectives on tonotopic FCT deep machine listening, and inter-species bioacoustic transfer learning to generalise the representation of animal communication systems.
[ { "version": "v1", "created": "Sat, 26 Nov 2016 22:16:35 GMT" }, { "version": "v2", "created": "Sun, 22 Jan 2017 22:28:47 GMT" } ]
2017-01-24T00:00:00
[ [ "Glotin", "Herve", "" ], [ "Ricard", "Julien", "" ], [ "Balestriero", "Randall", "" ] ]
TITLE: Fast Chirplet Transform to Enhance CNN Machine Listening - Validation on Animal calls and Speech ABSTRACT: The scattering framework offers an optimal hierarchical convolutional decomposition according to its kernels. Convolutional Neural Net (CNN) can be seen as an optimal kernel decomposition, nevertheless it requires large amount of training data to learn its kernels. We propose a trade-off between these two approaches: a Chirplet kernel as an efficient Q constant bioacoustic representation to pretrain CNN. First we motivate Chirplet bioinspired auditory representation. Second we give the first algorithm (and code) of a Fast Chirplet Transform (FCT). Third, we demonstrate the computation efficiency of FCT on large environmental data base: months of Orca recordings, and 1000 Birds species from the LifeClef challenge. Fourth, we validate FCT on the vowels subset of the Speech TIMIT dataset. The results show that FCT accelerates CNN when it pretrains low level layers: it reduces training duration by -28\% for birds classification, and by -26% for vowels classification. Scores are also enhanced by FCT pretraining, with a relative gain of +7.8% of Mean Average Precision on birds, and +2.3\% of vowel accuracy against raw audio CNN. We conclude on perspectives on tonotopic FCT deep machine listening, and inter-species bioacoustic transfer learning to generalise the representation of animal communication systems.
no_new_dataset
0.950319
1612.06027
Ryan Cotterell Ryan D Cotterell
Katharina Kann and Ryan Cotterell and Hinrich Sch\"utze
Neural Multi-Source Morphological Reinflection
Accepted at EACL 2017. Camera Ready Version
null
null
null
cs.CL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We explore the task of multi-source morphological reinflection, which generalizes the standard, single-source version. The input consists of (i) a target tag and (ii) multiple pairs of source form and source tag for a lemma. The motivation is that it is beneficial to have access to more than one source form since different source forms can provide complementary information, e.g., different stems. We further present a novel extension to the encoder- decoder recurrent neural architecture, consisting of multiple encoders, to better solve the task. We show that our new architecture outperforms single-source reinflection models and publish our dataset for multi-source morphological reinflection to facilitate future research.
[ { "version": "v1", "created": "Mon, 19 Dec 2016 02:21:24 GMT" }, { "version": "v2", "created": "Mon, 26 Dec 2016 06:22:45 GMT" }, { "version": "v3", "created": "Sun, 22 Jan 2017 09:30:10 GMT" } ]
2017-01-24T00:00:00
[ [ "Kann", "Katharina", "" ], [ "Cotterell", "Ryan", "" ], [ "Schütze", "Hinrich", "" ] ]
TITLE: Neural Multi-Source Morphological Reinflection ABSTRACT: We explore the task of multi-source morphological reinflection, which generalizes the standard, single-source version. The input consists of (i) a target tag and (ii) multiple pairs of source form and source tag for a lemma. The motivation is that it is beneficial to have access to more than one source form since different source forms can provide complementary information, e.g., different stems. We further present a novel extension to the encoder- decoder recurrent neural architecture, consisting of multiple encoders, to better solve the task. We show that our new architecture outperforms single-source reinflection models and publish our dataset for multi-source morphological reinflection to facilitate future research.
new_dataset
0.947962
1701.05923
Fathi Salem
Rahul Dey and Fathi M. Salem
Gate-Variants of Gated Recurrent Unit (GRU) Neural Networks
5 pages, 8 Figures, 4 Tables
null
null
null
cs.NE stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The paper evaluates three variants of the Gated Recurrent Unit (GRU) in recurrent neural networks (RNN) by reducing parameters in the update and reset gates. We evaluate the three variant GRU models on MNIST and IMDB datasets and show that these GRU-RNN variant models perform as well as the original GRU RNN model while reducing the computational expense.
[ { "version": "v1", "created": "Fri, 20 Jan 2017 20:53:51 GMT" } ]
2017-01-24T00:00:00
[ [ "Dey", "Rahul", "" ], [ "Salem", "Fathi M.", "" ] ]
TITLE: Gate-Variants of Gated Recurrent Unit (GRU) Neural Networks ABSTRACT: The paper evaluates three variants of the Gated Recurrent Unit (GRU) in recurrent neural networks (RNN) by reducing parameters in the update and reset gates. We evaluate the three variant GRU models on MNIST and IMDB datasets and show that these GRU-RNN variant models perform as well as the original GRU RNN model while reducing the computational expense.
no_new_dataset
0.953751
1701.05982
Sudhakar Singh
Sudhakar Singh, Rakhi Garg, P. K. Mishra
Observations on Factors Affecting Performance of MapReduce based Apriori on Hadoop Cluster
8 pages, 8 figures, International Conference on Computing, Communication and Automation (ICCCA2016)
2016 International Conference on Computing, Communication and Automation (ICCCA), Greater Noida, India, 2016, pp. 87-94
10.1109/CCAA.2016.7813695
466
cs.DB cs.DC cs.DS
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Designing fast and scalable algorithm for mining frequent itemsets is always being a most eminent and promising problem of data mining. Apriori is one of the most broadly used and popular algorithm of frequent itemset mining. Designing efficient algorithms on MapReduce framework to process and analyze big datasets is contemporary research nowadays. In this paper, we have focused on the performance of MapReduce based Apriori on homogeneous as well as on heterogeneous Hadoop cluster. We have investigated a number of factors that significantly affects the execution time of MapReduce based Apriori running on homogeneous and heterogeneous Hadoop Cluster. Factors are specific to both algorithmic and non-algorithmic improvements. Considered factors specific to algorithmic improvements are filtered transactions and data structures. Experimental results show that how an appropriate data structure and filtered transactions technique drastically reduce the execution time. The non-algorithmic factors include speculative execution, nodes with poor performance, data locality & distribution of data blocks, and parallelism control with input split size. We have applied strategies against these factors and fine tuned the relevant parameters in our particular application. Experimental results show that if cluster specific parameters are taken care of then there is a significant reduction in execution time. Also we have discussed the issues regarding MapReduce implementation of Apriori which may significantly influence the performance.
[ { "version": "v1", "created": "Sat, 21 Jan 2017 05:12:13 GMT" } ]
2017-01-24T00:00:00
[ [ "Singh", "Sudhakar", "" ], [ "Garg", "Rakhi", "" ], [ "Mishra", "P. K.", "" ] ]
TITLE: Observations on Factors Affecting Performance of MapReduce based Apriori on Hadoop Cluster ABSTRACT: Designing fast and scalable algorithm for mining frequent itemsets is always being a most eminent and promising problem of data mining. Apriori is one of the most broadly used and popular algorithm of frequent itemset mining. Designing efficient algorithms on MapReduce framework to process and analyze big datasets is contemporary research nowadays. In this paper, we have focused on the performance of MapReduce based Apriori on homogeneous as well as on heterogeneous Hadoop cluster. We have investigated a number of factors that significantly affects the execution time of MapReduce based Apriori running on homogeneous and heterogeneous Hadoop Cluster. Factors are specific to both algorithmic and non-algorithmic improvements. Considered factors specific to algorithmic improvements are filtered transactions and data structures. Experimental results show that how an appropriate data structure and filtered transactions technique drastically reduce the execution time. The non-algorithmic factors include speculative execution, nodes with poor performance, data locality & distribution of data blocks, and parallelism control with input split size. We have applied strategies against these factors and fine tuned the relevant parameters in our particular application. Experimental results show that if cluster specific parameters are taken care of then there is a significant reduction in execution time. Also we have discussed the issues regarding MapReduce implementation of Apriori which may significantly influence the performance.
no_new_dataset
0.946646
1701.06075
Linhong Zhu
Dingxiong Deng, Fan Bai, Yiqi Tang, Shuigeng Zhou, Cyrus Shahabi, Linhong Zhu
Label Propagation on K-partite Graphs with Heterophily
null
null
null
null
cs.LG cs.AI cs.SI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, for the first time, we study label propagation in heterogeneous graphs under heterophily assumption. Homophily label propagation (i.e., two connected nodes share similar labels) in homogeneous graph (with same types of vertices and relations) has been extensively studied before. Unfortunately, real-life networks are heterogeneous, they contain different types of vertices (e.g., users, images, texts) and relations (e.g., friendships, co-tagging) and allow for each node to propagate both the same and opposite copy of labels to its neighbors. We propose a $\mathcal{K}$-partite label propagation model to handle the mystifying combination of heterogeneous nodes/relations and heterophily propagation. With this model, we develop a novel label inference algorithm framework with update rules in near-linear time complexity. Since real networks change over time, we devise an incremental approach, which supports fast updates for both new data and evidence (e.g., ground truth labels) with guaranteed efficiency. We further provide a utility function to automatically determine whether an incremental or a re-modeling approach is favored. Extensive experiments on real datasets have verified the effectiveness and efficiency of our approach, and its superiority over the state-of-the-art label propagation methods.
[ { "version": "v1", "created": "Sat, 21 Jan 2017 19:47:38 GMT" } ]
2017-01-24T00:00:00
[ [ "Deng", "Dingxiong", "" ], [ "Bai", "Fan", "" ], [ "Tang", "Yiqi", "" ], [ "Zhou", "Shuigeng", "" ], [ "Shahabi", "Cyrus", "" ], [ "Zhu", "Linhong", "" ] ]
TITLE: Label Propagation on K-partite Graphs with Heterophily ABSTRACT: In this paper, for the first time, we study label propagation in heterogeneous graphs under heterophily assumption. Homophily label propagation (i.e., two connected nodes share similar labels) in homogeneous graph (with same types of vertices and relations) has been extensively studied before. Unfortunately, real-life networks are heterogeneous, they contain different types of vertices (e.g., users, images, texts) and relations (e.g., friendships, co-tagging) and allow for each node to propagate both the same and opposite copy of labels to its neighbors. We propose a $\mathcal{K}$-partite label propagation model to handle the mystifying combination of heterogeneous nodes/relations and heterophily propagation. With this model, we develop a novel label inference algorithm framework with update rules in near-linear time complexity. Since real networks change over time, we devise an incremental approach, which supports fast updates for both new data and evidence (e.g., ground truth labels) with guaranteed efficiency. We further provide a utility function to automatically determine whether an incremental or a re-modeling approach is favored. Extensive experiments on real datasets have verified the effectiveness and efficiency of our approach, and its superiority over the state-of-the-art label propagation methods.
no_new_dataset
0.951459
1701.06207
Akash Das Sarma
Ayush Jain, Akash Das Sarma, Aditya Parameswaran, Jennifer Widom
Understanding Workers, Developing Effective Tasks, and Enhancing Marketplace Dynamics: A Study of a Large Crowdsourcing Marketplace
null
null
null
null
cs.HC
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We conduct an experimental analysis of a dataset comprising over 27 million microtasks performed by over 70,000 workers issued to a large crowdsourcing marketplace between 2012-2016. Using this data---never before analyzed in an academic context---we shed light on three crucial aspects of crowdsourcing: (1) Task design --- helping requesters understand what constitutes an effective task, and how to go about designing one; (2) Marketplace dynamics --- helping marketplace administrators and designers understand the interaction between tasks and workers, and the corresponding marketplace load; and (3) Worker behavior --- understanding worker attention spans, lifetimes, and general behavior, for the improvement of the crowdsourcing ecosystem as a whole.
[ { "version": "v1", "created": "Sun, 22 Jan 2017 19:04:27 GMT" } ]
2017-01-24T00:00:00
[ [ "Jain", "Ayush", "" ], [ "Sarma", "Akash Das", "" ], [ "Parameswaran", "Aditya", "" ], [ "Widom", "Jennifer", "" ] ]
TITLE: Understanding Workers, Developing Effective Tasks, and Enhancing Marketplace Dynamics: A Study of a Large Crowdsourcing Marketplace ABSTRACT: We conduct an experimental analysis of a dataset comprising over 27 million microtasks performed by over 70,000 workers issued to a large crowdsourcing marketplace between 2012-2016. Using this data---never before analyzed in an academic context---we shed light on three crucial aspects of crowdsourcing: (1) Task design --- helping requesters understand what constitutes an effective task, and how to go about designing one; (2) Marketplace dynamics --- helping marketplace administrators and designers understand the interaction between tasks and workers, and the corresponding marketplace load; and (3) Worker behavior --- understanding worker attention spans, lifetimes, and general behavior, for the improvement of the crowdsourcing ecosystem as a whole.
no_new_dataset
0.675765
1701.06225
Omar Montasser
Omar Montasser and Daniel Kifer
Predicting Demographics of High-Resolution Geographies with Geotagged Tweets
6 pages, AAAI-17 preprint
null
null
null
cs.LG cs.SI stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we consider the problem of predicting demographics of geographic units given geotagged Tweets that are composed within these units. Traditional survey methods that offer demographics estimates are usually limited in terms of geographic resolution, geographic boundaries, and time intervals. Thus, it would be highly useful to develop computational methods that can complement traditional survey methods by offering demographics estimates at finer geographic resolutions, with flexible geographic boundaries (i.e. not confined to administrative boundaries), and at different time intervals. While prior work has focused on predicting demographics and health statistics at relatively coarse geographic resolutions such as the county-level or state-level, we introduce an approach to predict demographics at finer geographic resolutions such as the blockgroup-level. For the task of predicting gender and race/ethnicity counts at the blockgroup-level, an approach adapted from prior work to our problem achieves an average correlation of 0.389 (gender) and 0.569 (race) on a held-out test dataset. Our approach outperforms this prior approach with an average correlation of 0.671 (gender) and 0.692 (race).
[ { "version": "v1", "created": "Sun, 22 Jan 2017 22:16:46 GMT" } ]
2017-01-24T00:00:00
[ [ "Montasser", "Omar", "" ], [ "Kifer", "Daniel", "" ] ]
TITLE: Predicting Demographics of High-Resolution Geographies with Geotagged Tweets ABSTRACT: In this paper, we consider the problem of predicting demographics of geographic units given geotagged Tweets that are composed within these units. Traditional survey methods that offer demographics estimates are usually limited in terms of geographic resolution, geographic boundaries, and time intervals. Thus, it would be highly useful to develop computational methods that can complement traditional survey methods by offering demographics estimates at finer geographic resolutions, with flexible geographic boundaries (i.e. not confined to administrative boundaries), and at different time intervals. While prior work has focused on predicting demographics and health statistics at relatively coarse geographic resolutions such as the county-level or state-level, we introduce an approach to predict demographics at finer geographic resolutions such as the blockgroup-level. For the task of predicting gender and race/ethnicity counts at the blockgroup-level, an approach adapted from prior work to our problem achieves an average correlation of 0.389 (gender) and 0.569 (race) on a held-out test dataset. Our approach outperforms this prior approach with an average correlation of 0.671 (gender) and 0.692 (race).
no_new_dataset
0.946101
1701.06247
Hongjie Shi
Hongjie Shi, Takashi Ushio, Mitsuru Endo, Katsuyoshi Yamagami, Noriaki Horii
A Multichannel Convolutional Neural Network For Cross-language Dialog State Tracking
Copyright 2016 IEEE. Published in the 2016 IEEE Workshop on Spoken Language Technology (SLT 2016)
null
null
null
cs.CL cs.AI cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The fifth Dialog State Tracking Challenge (DSTC5) introduces a new cross-language dialog state tracking scenario, where the participants are asked to build their trackers based on the English training corpus, while evaluating them with the unlabeled Chinese corpus. Although the computer-generated translations for both English and Chinese corpus are provided in the dataset, these translations contain errors and careless use of them can easily hurt the performance of the built trackers. To address this problem, we propose a multichannel Convolutional Neural Networks (CNN) architecture, in which we treat English and Chinese language as different input channels of one single CNN model. In the evaluation of DSTC5, we found that such multichannel architecture can effectively improve the robustness against translation errors. Additionally, our method for DSTC5 is purely machine learning based and requires no prior knowledge about the target language. We consider this a desirable property for building a tracker in the cross-language context, as not every developer will be familiar with both languages.
[ { "version": "v1", "created": "Mon, 23 Jan 2017 01:36:10 GMT" } ]
2017-01-24T00:00:00
[ [ "Shi", "Hongjie", "" ], [ "Ushio", "Takashi", "" ], [ "Endo", "Mitsuru", "" ], [ "Yamagami", "Katsuyoshi", "" ], [ "Horii", "Noriaki", "" ] ]
TITLE: A Multichannel Convolutional Neural Network For Cross-language Dialog State Tracking ABSTRACT: The fifth Dialog State Tracking Challenge (DSTC5) introduces a new cross-language dialog state tracking scenario, where the participants are asked to build their trackers based on the English training corpus, while evaluating them with the unlabeled Chinese corpus. Although the computer-generated translations for both English and Chinese corpus are provided in the dataset, these translations contain errors and careless use of them can easily hurt the performance of the built trackers. To address this problem, we propose a multichannel Convolutional Neural Networks (CNN) architecture, in which we treat English and Chinese language as different input channels of one single CNN model. In the evaluation of DSTC5, we found that such multichannel architecture can effectively improve the robustness against translation errors. Additionally, our method for DSTC5 is purely machine learning based and requires no prior knowledge about the target language. We consider this a desirable property for building a tracker in the cross-language context, as not every developer will be familiar with both languages.
no_new_dataset
0.943815
1701.06276
Georgios Stylianou
Georgios Stylianou
Stay-point Identification as Curve Extrema
null
null
null
null
cs.OH
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In a nutshell, stay-points are locations that a person has stopped for some amount of time. Previous work depends mainly on stay-point identification methods using experimentally fine tuned threshold values. These behave well on their experimental datasets but may exhibit reduced performance on other datasets. In this work, we demonstrate the potential of a geometry-based method for stay-point extraction. This is accomplished by transforming the user's trajectory path to a two-dimensional discrete time series curve that in turn transforms the stay-points to the local minima of the first derivative of this curve. To demonstrate the soundness of the proposed method, we evaluated it on raw, noisy trajectory data acquired over the period of 28 different days using four different techniques. The results demonstrate, among others, that given a good trajectory tracking technique, we can identify correctly 86% to 98% of the stay-points.
[ { "version": "v1", "created": "Mon, 23 Jan 2017 06:45:01 GMT" } ]
2017-01-24T00:00:00
[ [ "Stylianou", "Georgios", "" ] ]
TITLE: Stay-point Identification as Curve Extrema ABSTRACT: In a nutshell, stay-points are locations that a person has stopped for some amount of time. Previous work depends mainly on stay-point identification methods using experimentally fine tuned threshold values. These behave well on their experimental datasets but may exhibit reduced performance on other datasets. In this work, we demonstrate the potential of a geometry-based method for stay-point extraction. This is accomplished by transforming the user's trajectory path to a two-dimensional discrete time series curve that in turn transforms the stay-points to the local minima of the first derivative of this curve. To demonstrate the soundness of the proposed method, we evaluated it on raw, noisy trajectory data acquired over the period of 28 different days using four different techniques. The results demonstrate, among others, that given a good trajectory tracking technique, we can identify correctly 86% to 98% of the stay-points.
no_new_dataset
0.944995
1701.06439
Teik Koon Cheang
Teik Koon Cheang, Yong Shean Chong, Yong Haur Tay
Segmentation-free Vehicle License Plate Recognition using ConvNet-RNN
5 pages, 3 figures, International Workshop on Advanced Image Technology, January, 8-10, 2017. Penang, Malaysia. Proceeding IWAIT2017
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
While vehicle license plate recognition (VLPR) is usually done with a sliding window approach, it can have limited performance on datasets with characters that are of variable width. This can be solved by hand-crafting algorithms to prescale the characters. While this approach can work fairly well, the recognizer is only aware of the pixels within each detector window, and fails to account for other contextual information that might be present in other parts of the image. A sliding window approach also requires training data in the form of presegmented characters, which can be more difficult to obtain. In this paper, we propose a unified ConvNet-RNN model to recognize real-world captured license plate photographs. By using a Convolutional Neural Network (ConvNet) to perform feature extraction and using a Recurrent Neural Network (RNN) for sequencing, we address the problem of sliding window approaches being unable to access the context of the entire image by feeding the entire image as input to the ConvNet. This has the added benefit of being able to perform end-to-end training of the entire model on labelled, full license plate images. Experimental results comparing the ConvNet-RNN architecture to a sliding window-based approach shows that the ConvNet-RNN architecture performs significantly better.
[ { "version": "v1", "created": "Mon, 23 Jan 2017 15:11:12 GMT" } ]
2017-01-24T00:00:00
[ [ "Cheang", "Teik Koon", "" ], [ "Chong", "Yong Shean", "" ], [ "Tay", "Yong Haur", "" ] ]
TITLE: Segmentation-free Vehicle License Plate Recognition using ConvNet-RNN ABSTRACT: While vehicle license plate recognition (VLPR) is usually done with a sliding window approach, it can have limited performance on datasets with characters that are of variable width. This can be solved by hand-crafting algorithms to prescale the characters. While this approach can work fairly well, the recognizer is only aware of the pixels within each detector window, and fails to account for other contextual information that might be present in other parts of the image. A sliding window approach also requires training data in the form of presegmented characters, which can be more difficult to obtain. In this paper, we propose a unified ConvNet-RNN model to recognize real-world captured license plate photographs. By using a Convolutional Neural Network (ConvNet) to perform feature extraction and using a Recurrent Neural Network (RNN) for sequencing, we address the problem of sliding window approaches being unable to access the context of the entire image by feeding the entire image as input to the ConvNet. This has the added benefit of being able to perform end-to-end training of the entire model on labelled, full license plate images. Experimental results comparing the ConvNet-RNN architecture to a sliding window-based approach shows that the ConvNet-RNN architecture performs significantly better.
no_new_dataset
0.948202
1701.06450
Andrea Baisero
Andrea Baisero, Stefan Otte, Peter Englert and Marc Toussaint
Identification of Unmodeled Objects from Symbolic Descriptions
null
null
null
null
stat.ML cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Successful human-robot cooperation hinges on each agent's ability to process and exchange information about the shared environment and the task at hand. Human communication is primarily based on symbolic abstractions of object properties, rather than precise quantitative measures. A comprehensive robotic framework thus requires an integrated communication module which is able to establish a link and convert between perceptual and abstract information. The ability to interpret composite symbolic descriptions enables an autonomous agent to a) operate in unstructured and cluttered environments, in tasks which involve unmodeled or never seen before objects; and b) exploit the aggregation of multiple symbolic properties as an instance of ensemble learning, to improve identification performance even when the individual predicates encode generic information or are imprecisely grounded. We propose a discriminative probabilistic model which interprets symbolic descriptions to identify the referent object contextually w.r.t.\ the structure of the environment and other objects. The model is trained using a collected dataset of identifications, and its performance is evaluated by quantitative measures and a live demo developed on the PR2 robot platform, which integrates elements of perception, object extraction, object identification and grasping.
[ { "version": "v1", "created": "Mon, 23 Jan 2017 15:26:01 GMT" } ]
2017-01-24T00:00:00
[ [ "Baisero", "Andrea", "" ], [ "Otte", "Stefan", "" ], [ "Englert", "Peter", "" ], [ "Toussaint", "Marc", "" ] ]
TITLE: Identification of Unmodeled Objects from Symbolic Descriptions ABSTRACT: Successful human-robot cooperation hinges on each agent's ability to process and exchange information about the shared environment and the task at hand. Human communication is primarily based on symbolic abstractions of object properties, rather than precise quantitative measures. A comprehensive robotic framework thus requires an integrated communication module which is able to establish a link and convert between perceptual and abstract information. The ability to interpret composite symbolic descriptions enables an autonomous agent to a) operate in unstructured and cluttered environments, in tasks which involve unmodeled or never seen before objects; and b) exploit the aggregation of multiple symbolic properties as an instance of ensemble learning, to improve identification performance even when the individual predicates encode generic information or are imprecisely grounded. We propose a discriminative probabilistic model which interprets symbolic descriptions to identify the referent object contextually w.r.t.\ the structure of the environment and other objects. The model is trained using a collected dataset of identifications, and its performance is evaluated by quantitative measures and a live demo developed on the PR2 robot platform, which integrates elements of perception, object extraction, object identification and grasping.
no_new_dataset
0.943348
1701.06462
Eu Koon Cheang
Eu Koon Cheang, Teik Koon Cheang, Yong Haur Tay
Using Convolutional Neural Networks to Count Palm Trees in Satellite Images
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we propose a supervised learning system for counting and localizing palm trees in high-resolution, panchromatic satellite imagery (40cm/pixel to 1.5m/pixel). A convolutional neural network classifier trained on a set of palm and no-palm images is applied across a satellite image scene in a sliding window fashion. The resultant confidence map is smoothed with a uniform filter. A non-maximal suppression is applied onto the smoothed confidence map to obtain peaks. Trained with a small dataset of 500 images of size 40x40 cropped from satellite images, the system manages to achieve a tree count accuracy of over 99%.
[ { "version": "v1", "created": "Mon, 23 Jan 2017 15:38:52 GMT" } ]
2017-01-24T00:00:00
[ [ "Cheang", "Eu Koon", "" ], [ "Cheang", "Teik Koon", "" ], [ "Tay", "Yong Haur", "" ] ]
TITLE: Using Convolutional Neural Networks to Count Palm Trees in Satellite Images ABSTRACT: In this paper we propose a supervised learning system for counting and localizing palm trees in high-resolution, panchromatic satellite imagery (40cm/pixel to 1.5m/pixel). A convolutional neural network classifier trained on a set of palm and no-palm images is applied across a satellite image scene in a sliding window fashion. The resultant confidence map is smoothed with a uniform filter. A non-maximal suppression is applied onto the smoothed confidence map to obtain peaks. Trained with a small dataset of 500 images of size 40x40 cropped from satellite images, the system manages to achieve a tree count accuracy of over 99%.
no_new_dataset
0.627352
1609.04214
Shujun Li Dr.
Aamo Iorliam, Santosh Tirunagari, Anthony T.S. Ho, Shujun Li, Adrian Waller and Norman Poh
"Flow Size Difference" Can Make a Difference: Detecting Malicious TCP Network Flows Based on Benford's Law
13 pages, 3 figures
null
null
null
cs.CR cs.AI cs.NI
http://creativecommons.org/licenses/by-nc-sa/4.0/
Statistical characteristics of network traffic have attracted a significant amount of research for automated network intrusion detection, some of which looked at applications of natural statistical laws such as Zipf's law, Benford's law and the Pareto distribution. In this paper, we present the application of Benford's law to a new network flow metric "flow size difference", which have not been studied before by other researchers, to build an unsupervised flow-based intrusion detection system (IDS). The method was inspired by our observation on a large number of TCP flow datasets where normal flows tend to follow Benford's law closely but malicious flows tend to deviate significantly from it. The proposed IDS is unsupervised, so it can be easily deployed without any training. It has two simple operational parameters with a clear semantic meaning, allowing the IDS operator to set and adapt their values intuitively to adjust the overall performance of the IDS. We tested the proposed IDS on two (one closed and one public) datasets, and proved its efficiency in terms of AUC (area under the ROC curve). Our work showed the "flow size difference" has a great potential to improve the performance of any flow-based network IDSs.
[ { "version": "v1", "created": "Wed, 14 Sep 2016 10:51:00 GMT" }, { "version": "v2", "created": "Fri, 20 Jan 2017 18:22:47 GMT" } ]
2017-01-23T00:00:00
[ [ "Iorliam", "Aamo", "" ], [ "Tirunagari", "Santosh", "" ], [ "Ho", "Anthony T. S.", "" ], [ "Li", "Shujun", "" ], [ "Waller", "Adrian", "" ], [ "Poh", "Norman", "" ] ]
TITLE: "Flow Size Difference" Can Make a Difference: Detecting Malicious TCP Network Flows Based on Benford's Law ABSTRACT: Statistical characteristics of network traffic have attracted a significant amount of research for automated network intrusion detection, some of which looked at applications of natural statistical laws such as Zipf's law, Benford's law and the Pareto distribution. In this paper, we present the application of Benford's law to a new network flow metric "flow size difference", which have not been studied before by other researchers, to build an unsupervised flow-based intrusion detection system (IDS). The method was inspired by our observation on a large number of TCP flow datasets where normal flows tend to follow Benford's law closely but malicious flows tend to deviate significantly from it. The proposed IDS is unsupervised, so it can be easily deployed without any training. It has two simple operational parameters with a clear semantic meaning, allowing the IDS operator to set and adapt their values intuitively to adjust the overall performance of the IDS. We tested the proposed IDS on two (one closed and one public) datasets, and proved its efficiency in terms of AUC (area under the ROC curve). Our work showed the "flow size difference" has a great potential to improve the performance of any flow-based network IDSs.
no_new_dataset
0.950365
1701.05581
Diptesh Kanojia
Abhijit Mishra, Diptesh Kanojia, Seema Nagar, Kuntal Dey and Pushpak Bhattacharyya
Leveraging Cognitive Features for Sentiment Analysis
The SIGNLL Conference on Computational Natural Language Learning (CoNLL 2016)
null
null
null
cs.CL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Sentiments expressed in user-generated short text and sentences are nuanced by subtleties at lexical, syntactic, semantic and pragmatic levels. To address this, we propose to augment traditional features used for sentiment analysis and sarcasm detection, with cognitive features derived from the eye-movement patterns of readers. Statistical classification using our enhanced feature set improves the performance (F-score) of polarity detection by a maximum of 3.7% and 9.3% on two datasets, over the systems that use only traditional features. We perform feature significance analysis, and experiment on a held-out dataset, showing that cognitive features indeed empower sentiment analyzers to handle complex constructs.
[ { "version": "v1", "created": "Thu, 19 Jan 2017 19:58:26 GMT" } ]
2017-01-23T00:00:00
[ [ "Mishra", "Abhijit", "" ], [ "Kanojia", "Diptesh", "" ], [ "Nagar", "Seema", "" ], [ "Dey", "Kuntal", "" ], [ "Bhattacharyya", "Pushpak", "" ] ]
TITLE: Leveraging Cognitive Features for Sentiment Analysis ABSTRACT: Sentiments expressed in user-generated short text and sentences are nuanced by subtleties at lexical, syntactic, semantic and pragmatic levels. To address this, we propose to augment traditional features used for sentiment analysis and sarcasm detection, with cognitive features derived from the eye-movement patterns of readers. Statistical classification using our enhanced feature set improves the performance (F-score) of polarity detection by a maximum of 3.7% and 9.3% on two datasets, over the systems that use only traditional features. We perform feature significance analysis, and experiment on a held-out dataset, showing that cognitive features indeed empower sentiment analyzers to handle complex constructs.
no_new_dataset
0.935759
1701.05595
Mohammad Mahmoodi
Mohammad Reza Mahmoodi
Fast and Efficient Skin Detection for Facial Detection
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, an efficient skin detection system is proposed. The algorithm is based on a very fast efficient pre-processing step utilizing the concept of ternary conversion in order to identify candidate windows and subsequently, a novel local two-stage diffusion method which has F-score accuracy of 0.5978 on SDD dataset. The pre-processing step has been proven to be useful to boost the speed of the system by eliminating 82% of an image in average. This is obtained by keeping the true positive rate above 98%. In addition, a novel segmentation algorithm is also designed to process candidate windows which is quantitatively and qualitatively proven to be very efficient in term of accuracy. The algorithm has been implemented in FPGA to obtain real-time processing speed. The system is designed fully pipeline and the inherent parallel structure of the algorithm is fully exploited to maximize the performance. The system is implemented on a Spartan-6 LXT45 Xilinx FPGA and it is capable of processing 98 frames of 640*480 24-bit color images per second.
[ { "version": "v1", "created": "Thu, 19 Jan 2017 20:43:27 GMT" } ]
2017-01-23T00:00:00
[ [ "Mahmoodi", "Mohammad Reza", "" ] ]
TITLE: Fast and Efficient Skin Detection for Facial Detection ABSTRACT: In this paper, an efficient skin detection system is proposed. The algorithm is based on a very fast efficient pre-processing step utilizing the concept of ternary conversion in order to identify candidate windows and subsequently, a novel local two-stage diffusion method which has F-score accuracy of 0.5978 on SDD dataset. The pre-processing step has been proven to be useful to boost the speed of the system by eliminating 82% of an image in average. This is obtained by keeping the true positive rate above 98%. In addition, a novel segmentation algorithm is also designed to process candidate windows which is quantitatively and qualitatively proven to be very efficient in term of accuracy. The algorithm has been implemented in FPGA to obtain real-time processing speed. The system is designed fully pipeline and the inherent parallel structure of the algorithm is fully exploited to maximize the performance. The system is implemented on a Spartan-6 LXT45 Xilinx FPGA and it is capable of processing 98 frames of 640*480 24-bit color images per second.
no_new_dataset
0.949295
1701.05596
Roger Schaer
Dimitrios Markonis, Roger Schaer, Alba Garc\'ia Seco de Herrera, Henning M\"uller
The Parallel Distributed Image Search Engine (ParaDISE)
23 pages, 9 figures
null
null
null
cs.IR
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Image retrieval is a complex task that differs according to the context and the user requirements in any specific field, for example in a medical environment. Search by text is often not possible or optimal and retrieval by the visual content does not always succeed in modelling high-level concepts that a user is looking for. Modern image retrieval techniques consist of multiple steps and aim to retrieve information from large--scale datasets and not only based on global image appearance but local features and if possible in a connection between visual features and text or semantics. This paper presents the Parallel Distributed Image Search Engine (ParaDISE), an image retrieval system that combines visual search with text--based retrieval and that is available as open source and free of charge. The main design concepts of ParaDISE are flexibility, expandability, scalability and interoperability. These concepts constitute the system, able to be used both in real-world applications and as an image retrieval research platform. Apart from the architecture and the implementation of the system, two use cases are described, an application of ParaDISE in retrieval of images from the medical literature and a visual feature evaluation for medical image retrieval. Future steps include the creation of an open source community that will contribute and expand this platform based on the existing parts.
[ { "version": "v1", "created": "Thu, 19 Jan 2017 20:51:56 GMT" } ]
2017-01-23T00:00:00
[ [ "Markonis", "Dimitrios", "" ], [ "Schaer", "Roger", "" ], [ "de Herrera", "Alba García Seco", "" ], [ "Müller", "Henning", "" ] ]
TITLE: The Parallel Distributed Image Search Engine (ParaDISE) ABSTRACT: Image retrieval is a complex task that differs according to the context and the user requirements in any specific field, for example in a medical environment. Search by text is often not possible or optimal and retrieval by the visual content does not always succeed in modelling high-level concepts that a user is looking for. Modern image retrieval techniques consist of multiple steps and aim to retrieve information from large--scale datasets and not only based on global image appearance but local features and if possible in a connection between visual features and text or semantics. This paper presents the Parallel Distributed Image Search Engine (ParaDISE), an image retrieval system that combines visual search with text--based retrieval and that is available as open source and free of charge. The main design concepts of ParaDISE are flexibility, expandability, scalability and interoperability. These concepts constitute the system, able to be used both in real-world applications and as an image retrieval research platform. Apart from the architecture and the implementation of the system, two use cases are described, an application of ParaDISE in retrieval of images from the medical literature and a visual feature evaluation for medical image retrieval. Future steps include the creation of an open source community that will contribute and expand this platform based on the existing parts.
no_new_dataset
0.949342
1701.05632
Simon Angus
Klaus Ackermann, Simon D Angus, Paul A Raschky
The Internet as Quantitative Social Science Platform: Insights from a Trillion Observations
40 pages, including 4 main figures, and appendix
null
null
null
q-fin.EC cs.CY cs.SI physics.soc-ph stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
With the large-scale penetration of the internet, for the first time, humanity has become linked by a single, open, communications platform. Harnessing this fact, we report insights arising from a unified internet activity and location dataset of an unparalleled scope and accuracy drawn from over a trillion (1.5$\times 10^{12}$) observations of end-user internet connections, with temporal resolution of just 15min over 2006-2012. We first apply this dataset to the expansion of the internet itself over 1,647 urban agglomerations globally. We find that unique IP per capita counts reach saturation at approximately one IP per three people, and take, on average, 16.1 years to achieve; eclipsing the estimated 100- and 60- year saturation times for steam-power and electrification respectively. Next, we use intra-diurnal internet activity features to up-scale traditional over-night sleep observations, producing the first global estimate of over-night sleep duration in 645 cities over 7 years. We find statistically significant variation between continental, national and regional sleep durations including some evidence of global sleep duration convergence. Finally, we estimate the relationship between internet concentration and economic outcomes in 411 OECD regions and find that the internet's expansion is associated with negative or positive productivity gains, depending strongly on sectoral considerations. To our knowledge, our study is the first of its kind to use online/offline activity of the entire internet to infer social science insights, demonstrating the unparalleled potential of the internet as a social data-science platform.
[ { "version": "v1", "created": "Thu, 19 Jan 2017 22:35:46 GMT" } ]
2017-01-23T00:00:00
[ [ "Ackermann", "Klaus", "" ], [ "Angus", "Simon D", "" ], [ "Raschky", "Paul A", "" ] ]
TITLE: The Internet as Quantitative Social Science Platform: Insights from a Trillion Observations ABSTRACT: With the large-scale penetration of the internet, for the first time, humanity has become linked by a single, open, communications platform. Harnessing this fact, we report insights arising from a unified internet activity and location dataset of an unparalleled scope and accuracy drawn from over a trillion (1.5$\times 10^{12}$) observations of end-user internet connections, with temporal resolution of just 15min over 2006-2012. We first apply this dataset to the expansion of the internet itself over 1,647 urban agglomerations globally. We find that unique IP per capita counts reach saturation at approximately one IP per three people, and take, on average, 16.1 years to achieve; eclipsing the estimated 100- and 60- year saturation times for steam-power and electrification respectively. Next, we use intra-diurnal internet activity features to up-scale traditional over-night sleep observations, producing the first global estimate of over-night sleep duration in 645 cities over 7 years. We find statistically significant variation between continental, national and regional sleep durations including some evidence of global sleep duration convergence. Finally, we estimate the relationship between internet concentration and economic outcomes in 411 OECD regions and find that the internet's expansion is associated with negative or positive productivity gains, depending strongly on sectoral considerations. To our knowledge, our study is the first of its kind to use online/offline activity of the entire internet to infer social science insights, demonstrating the unparalleled potential of the internet as a social data-science platform.
no_new_dataset
0.932207
1701.05779
Sungho Jeon
Sungho Jeon, Jong-Woo Shin, Young-Jun Lee, Woong-Hee Kim, YoungHyoun Kwon, and Hae-Yong Yang
Empirical Study of Drone Sound Detection in Real-Life Environment with Deep Neural Networks
IEEE 5 Pages, Submitted
null
null
null
cs.SD cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This work aims to investigate the use of deep neural network to detect commercial hobby drones in real-life environments by analyzing their sound data. The purpose of work is to contribute to a system for detecting drones used for malicious purposes, such as for terrorism. Specifically, we present a method capable of detecting the presence of commercial hobby drones as a binary classification problem based on sound event detection. We recorded the sound produced by a few popular commercial hobby drones, and then augmented this data with diverse environmental sound data to remedy the scarcity of drone sound data in diverse environments. We investigated the effectiveness of state-of-the-art event sound classification methods, i.e., a Gaussian Mixture Model (GMM), Convolutional Neural Network (CNN), and Recurrent Neural Network (RNN), for drone sound detection. Our empirical results, which were obtained with a testing dataset collected on an urban street, confirmed the effectiveness of these models for operating in a real environment. In summary, our RNN models showed the best detection performance with an F-Score of 0.8009 with 240 ms of input audio with a short processing time, indicating their applicability to real-time detection systems.
[ { "version": "v1", "created": "Fri, 20 Jan 2017 12:48:02 GMT" } ]
2017-01-23T00:00:00
[ [ "Jeon", "Sungho", "" ], [ "Shin", "Jong-Woo", "" ], [ "Lee", "Young-Jun", "" ], [ "Kim", "Woong-Hee", "" ], [ "Kwon", "YoungHyoun", "" ], [ "Yang", "Hae-Yong", "" ] ]
TITLE: Empirical Study of Drone Sound Detection in Real-Life Environment with Deep Neural Networks ABSTRACT: This work aims to investigate the use of deep neural network to detect commercial hobby drones in real-life environments by analyzing their sound data. The purpose of work is to contribute to a system for detecting drones used for malicious purposes, such as for terrorism. Specifically, we present a method capable of detecting the presence of commercial hobby drones as a binary classification problem based on sound event detection. We recorded the sound produced by a few popular commercial hobby drones, and then augmented this data with diverse environmental sound data to remedy the scarcity of drone sound data in diverse environments. We investigated the effectiveness of state-of-the-art event sound classification methods, i.e., a Gaussian Mixture Model (GMM), Convolutional Neural Network (CNN), and Recurrent Neural Network (RNN), for drone sound detection. Our empirical results, which were obtained with a testing dataset collected on an urban street, confirmed the effectiveness of these models for operating in a real environment. In summary, our RNN models showed the best detection performance with an F-Score of 0.8009 with 240 ms of input audio with a short processing time, indicating their applicability to real-time detection systems.
no_new_dataset
0.941868
1701.05818
Nicolas Audebert
Nicolas Audebert (Palaiseau, OBELIX), Bertrand Le Saux (Palaiseau), S\'ebastien Lef\`evre (OBELIX)
Fusion of Heterogeneous Data in Convolutional Networks for Urban Semantic Labeling (Invited Paper)
Joint Urban Remote Sensing Event (JURSE), Mar 2017, Dubai, United Arab Emirates. Joint Urban Remote Sensing Event 2017
null
null
null
cs.NE cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work, we present a novel module to perform fusion of heterogeneous data using fully convolutional networks for semantic labeling. We introduce residual correction as a way to learn how to fuse predictions coming out of a dual stream architecture. Especially, we perform fusion of DSM and IRRG optical data on the ISPRS Vaihingen dataset over a urban area and obtain new state-of-the-art results.
[ { "version": "v1", "created": "Fri, 20 Jan 2017 15:10:09 GMT" } ]
2017-01-23T00:00:00
[ [ "Audebert", "Nicolas", "", "Palaiseau, OBELIX" ], [ "Saux", "Bertrand Le", "", "Palaiseau" ], [ "Lefèvre", "Sébastien", "", "OBELIX" ] ]
TITLE: Fusion of Heterogeneous Data in Convolutional Networks for Urban Semantic Labeling (Invited Paper) ABSTRACT: In this work, we present a novel module to perform fusion of heterogeneous data using fully convolutional networks for semantic labeling. We introduce residual correction as a way to learn how to fuse predictions coming out of a dual stream architecture. Especially, we perform fusion of DSM and IRRG optical data on the ISPRS Vaihingen dataset over a urban area and obtain new state-of-the-art results.
no_new_dataset
0.951278
1606.00061
Jiasen Lu
Jiasen Lu, Jianwei Yang, Dhruv Batra, Devi Parikh
Hierarchical Question-Image Co-Attention for Visual Question Answering
11 pages, 7 figures, 3 tables in 2016 Conference on Neural Information Processing Systems (NIPS)
null
null
null
cs.CV cs.CL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A number of recent works have proposed attention models for Visual Question Answering (VQA) that generate spatial maps highlighting image regions relevant to answering the question. In this paper, we argue that in addition to modeling "where to look" or visual attention, it is equally important to model "what words to listen to" or question attention. We present a novel co-attention model for VQA that jointly reasons about image and question attention. In addition, our model reasons about the question (and consequently the image via the co-attention mechanism) in a hierarchical fashion via a novel 1-dimensional convolution neural networks (CNN). Our model improves the state-of-the-art on the VQA dataset from 60.3% to 60.5%, and from 61.6% to 63.3% on the COCO-QA dataset. By using ResNet, the performance is further improved to 62.1% for VQA and 65.4% for COCO-QA.
[ { "version": "v1", "created": "Tue, 31 May 2016 22:02:01 GMT" }, { "version": "v2", "created": "Thu, 2 Jun 2016 01:51:13 GMT" }, { "version": "v3", "created": "Wed, 26 Oct 2016 02:15:57 GMT" }, { "version": "v4", "created": "Fri, 13 Jan 2017 16:18:03 GMT" }, { "version": "v5", "created": "Thu, 19 Jan 2017 05:03:33 GMT" } ]
2017-01-20T00:00:00
[ [ "Lu", "Jiasen", "" ], [ "Yang", "Jianwei", "" ], [ "Batra", "Dhruv", "" ], [ "Parikh", "Devi", "" ] ]
TITLE: Hierarchical Question-Image Co-Attention for Visual Question Answering ABSTRACT: A number of recent works have proposed attention models for Visual Question Answering (VQA) that generate spatial maps highlighting image regions relevant to answering the question. In this paper, we argue that in addition to modeling "where to look" or visual attention, it is equally important to model "what words to listen to" or question attention. We present a novel co-attention model for VQA that jointly reasons about image and question attention. In addition, our model reasons about the question (and consequently the image via the co-attention mechanism) in a hierarchical fashion via a novel 1-dimensional convolution neural networks (CNN). Our model improves the state-of-the-art on the VQA dataset from 60.3% to 60.5%, and from 61.6% to 63.3% on the COCO-QA dataset. By using ResNet, the performance is further improved to 62.1% for VQA and 65.4% for COCO-QA.
no_new_dataset
0.954774
1606.09075
John V Monaco
John V. Monaco
Robust Keystroke Biometric Anomaly Detection
null
null
null
null
cs.CR
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Keystroke Biometrics Ongoing Competition (KBOC) presented an anomaly detection challenge with a public keystroke dataset containing a large number of subjects and real-world aspects. Over 300 subjects typed case-insensitive repetitions of their first and last name, and as a result, keystroke sequences could vary in length and order depending on the usage of modifier keys. To deal with this, a keystroke alignment preprocessing algorithm was developed to establish a semantic correspondence between keystrokes in mismatched sequences. The method is robust in the sense that query keystroke sequences need only approximately match a target sequence, and alignment is agnostic to the particular anomaly detector used. This paper describes the fifteen best-performing anomaly detection systems submitted to the KBOC, which ranged from auto-encoding neural networks to ensemble methods. Manhattan distance achieved the lowest equal error rate of 5.32%, while all fifteen systems performed better than any other submission. Performance gains are shown to be due in large part not to the particular anomaly detector, but to preprocessing and score normalization techniques.
[ { "version": "v1", "created": "Wed, 29 Jun 2016 13:09:29 GMT" }, { "version": "v2", "created": "Wed, 18 Jan 2017 19:19:00 GMT" } ]
2017-01-20T00:00:00
[ [ "Monaco", "John V.", "" ] ]
TITLE: Robust Keystroke Biometric Anomaly Detection ABSTRACT: The Keystroke Biometrics Ongoing Competition (KBOC) presented an anomaly detection challenge with a public keystroke dataset containing a large number of subjects and real-world aspects. Over 300 subjects typed case-insensitive repetitions of their first and last name, and as a result, keystroke sequences could vary in length and order depending on the usage of modifier keys. To deal with this, a keystroke alignment preprocessing algorithm was developed to establish a semantic correspondence between keystrokes in mismatched sequences. The method is robust in the sense that query keystroke sequences need only approximately match a target sequence, and alignment is agnostic to the particular anomaly detector used. This paper describes the fifteen best-performing anomaly detection systems submitted to the KBOC, which ranged from auto-encoding neural networks to ensemble methods. Manhattan distance achieved the lowest equal error rate of 5.32%, while all fifteen systems performed better than any other submission. Performance gains are shown to be due in large part not to the particular anomaly detector, but to preprocessing and score normalization techniques.
no_new_dataset
0.783906
1701.05105
Zetao Chen
Zetao Chen, Adam Jacobson, Niko Sunderhauf, Ben Upcroft, Lingqiao Liu, Chunhua Shen, Ian Reid and Michael Milford
Deep Learning Features at Scale for Visual Place Recognition
8 pages, 10 figures. Accepted by International Conference on Robotics and Automation (ICRA) 2017. This is the submitted version. The final published version may be slightly different
null
null
null
cs.CV cs.RO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The success of deep learning techniques in the computer vision domain has triggered a range of initial investigations into their utility for visual place recognition, all using generic features from networks that were trained for other types of recognition tasks. In this paper, we train, at large scale, two CNN architectures for the specific place recognition task and employ a multi-scale feature encoding method to generate condition- and viewpoint-invariant features. To enable this training to occur, we have developed a massive Specific PlacEs Dataset (SPED) with hundreds of examples of place appearance change at thousands of different places, as opposed to the semantic place type datasets currently available. This new dataset enables us to set up a training regime that interprets place recognition as a classification problem. We comprehensively evaluate our trained networks on several challenging benchmark place recognition datasets and demonstrate that they achieve an average 10% increase in performance over other place recognition algorithms and pre-trained CNNs. By analyzing the network responses and their differences from pre-trained networks, we provide insights into what a network learns when training for place recognition, and what these results signify for future research in this area.
[ { "version": "v1", "created": "Wed, 18 Jan 2017 16:28:03 GMT" } ]
2017-01-20T00:00:00
[ [ "Chen", "Zetao", "" ], [ "Jacobson", "Adam", "" ], [ "Sunderhauf", "Niko", "" ], [ "Upcroft", "Ben", "" ], [ "Liu", "Lingqiao", "" ], [ "Shen", "Chunhua", "" ], [ "Reid", "Ian", "" ], [ "Milford", "Michael", "" ] ]
TITLE: Deep Learning Features at Scale for Visual Place Recognition ABSTRACT: The success of deep learning techniques in the computer vision domain has triggered a range of initial investigations into their utility for visual place recognition, all using generic features from networks that were trained for other types of recognition tasks. In this paper, we train, at large scale, two CNN architectures for the specific place recognition task and employ a multi-scale feature encoding method to generate condition- and viewpoint-invariant features. To enable this training to occur, we have developed a massive Specific PlacEs Dataset (SPED) with hundreds of examples of place appearance change at thousands of different places, as opposed to the semantic place type datasets currently available. This new dataset enables us to set up a training regime that interprets place recognition as a classification problem. We comprehensively evaluate our trained networks on several challenging benchmark place recognition datasets and demonstrate that they achieve an average 10% increase in performance over other place recognition algorithms and pre-trained CNNs. By analyzing the network responses and their differences from pre-trained networks, we provide insights into what a network learns when training for place recognition, and what these results signify for future research in this area.
new_dataset
0.956268
1701.05360
James Booth
James Booth, Epameinondas Antonakos, Stylianos Ploumpis, George Trigeorgis, Yannis Panagakis, and Stefanos Zafeiriou
3D Face Morphable Models "In-the-Wild"
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
3D Morphable Models (3DMMs) are powerful statistical models of 3D facial shape and texture, and among the state-of-the-art methods for reconstructing facial shape from single images. With the advent of new 3D sensors, many 3D facial datasets have been collected containing both neutral as well as expressive faces. However, all datasets are captured under controlled conditions. Thus, even though powerful 3D facial shape models can be learnt from such data, it is difficult to build statistical texture models that are sufficient to reconstruct faces captured in unconstrained conditions ("in-the-wild"). In this paper, we propose the first, to the best of our knowledge, "in-the-wild" 3DMM by combining a powerful statistical model of facial shape, which describes both identity and expression, with an "in-the-wild" texture model. We show that the employment of such an "in-the-wild" texture model greatly simplifies the fitting procedure, because there is no need to optimize with regards to the illumination parameters. Furthermore, we propose a new fast algorithm for fitting the 3DMM in arbitrary images. Finally, we have captured the first 3D facial database with relatively unconstrained conditions and report quantitative evaluations with state-of-the-art performance. Complementary qualitative reconstruction results are demonstrated on standard "in-the-wild" facial databases. An open source implementation of our technique is released as part of the Menpo Project.
[ { "version": "v1", "created": "Thu, 19 Jan 2017 10:27:38 GMT" } ]
2017-01-20T00:00:00
[ [ "Booth", "James", "" ], [ "Antonakos", "Epameinondas", "" ], [ "Ploumpis", "Stylianos", "" ], [ "Trigeorgis", "George", "" ], [ "Panagakis", "Yannis", "" ], [ "Zafeiriou", "Stefanos", "" ] ]
TITLE: 3D Face Morphable Models "In-the-Wild" ABSTRACT: 3D Morphable Models (3DMMs) are powerful statistical models of 3D facial shape and texture, and among the state-of-the-art methods for reconstructing facial shape from single images. With the advent of new 3D sensors, many 3D facial datasets have been collected containing both neutral as well as expressive faces. However, all datasets are captured under controlled conditions. Thus, even though powerful 3D facial shape models can be learnt from such data, it is difficult to build statistical texture models that are sufficient to reconstruct faces captured in unconstrained conditions ("in-the-wild"). In this paper, we propose the first, to the best of our knowledge, "in-the-wild" 3DMM by combining a powerful statistical model of facial shape, which describes both identity and expression, with an "in-the-wild" texture model. We show that the employment of such an "in-the-wild" texture model greatly simplifies the fitting procedure, because there is no need to optimize with regards to the illumination parameters. Furthermore, we propose a new fast algorithm for fitting the 3DMM in arbitrary images. Finally, we have captured the first 3D facial database with relatively unconstrained conditions and report quantitative evaluations with state-of-the-art performance. Complementary qualitative reconstruction results are demonstrated on standard "in-the-wild" facial databases. An open source implementation of our technique is released as part of the Menpo Project.
no_new_dataset
0.945651
1701.05378
Burak Civek
Burak C. Civek and Suleyman S. Kozat
Efficient Implementation Of Newton-Raphson Methods For Sequential Data Prediction
null
null
null
null
cs.DS cs.CC cs.NA
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the problem of sequential linear data prediction for real life big data applications. The second order algorithms, i.e., Newton-Raphson Methods, asymptotically achieve the performance of the "best" possible linear data predictor much faster compared to the first order algorithms, e.g., Online Gradient Descent. However, implementation of these methods is not usually feasible in big data applications because of the extremely high computational needs. Regular implementation of the Newton-Raphson Methods requires a computational complexity in the order of $O(M^2)$ for an $M$ dimensional feature vector, while the first order algorithms need only $O(M)$. To this end, in order to eliminate this gap, we introduce a highly efficient implementation reducing the computational complexity of the Newton-Raphson Methods from quadratic to linear scale. The presented algorithm provides the well-known merits of the second order methods while offering the computational complexity of $O(M)$. We utilize the shifted nature of the consecutive feature vectors and do not rely on any statistical assumptions. Therefore, both regular and fast implementations achieve the same performance in the sense of mean square error. We demonstrate the computational efficiency of our algorithm on real life sequential big datasets. We also illustrate that the presented algorithm is numerically stable.
[ { "version": "v1", "created": "Thu, 19 Jan 2017 11:34:17 GMT" } ]
2017-01-20T00:00:00
[ [ "Civek", "Burak C.", "" ], [ "Kozat", "Suleyman S.", "" ] ]
TITLE: Efficient Implementation Of Newton-Raphson Methods For Sequential Data Prediction ABSTRACT: We investigate the problem of sequential linear data prediction for real life big data applications. The second order algorithms, i.e., Newton-Raphson Methods, asymptotically achieve the performance of the "best" possible linear data predictor much faster compared to the first order algorithms, e.g., Online Gradient Descent. However, implementation of these methods is not usually feasible in big data applications because of the extremely high computational needs. Regular implementation of the Newton-Raphson Methods requires a computational complexity in the order of $O(M^2)$ for an $M$ dimensional feature vector, while the first order algorithms need only $O(M)$. To this end, in order to eliminate this gap, we introduce a highly efficient implementation reducing the computational complexity of the Newton-Raphson Methods from quadratic to linear scale. The presented algorithm provides the well-known merits of the second order methods while offering the computational complexity of $O(M)$. We utilize the shifted nature of the consecutive feature vectors and do not rely on any statistical assumptions. Therefore, both regular and fast implementations achieve the same performance in the sense of mean square error. We demonstrate the computational efficiency of our algorithm on real life sequential big datasets. We also illustrate that the presented algorithm is numerically stable.
no_new_dataset
0.946498
1701.05432
Anoop Cherian
Anoop Cherian, Piotr Koniusz, Stephen Gould
Higher-order Pooling of CNN Features via Kernel Linearization for Action Recognition
9 pages
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Most successful deep learning algorithms for action recognition extend models designed for image-based tasks such as object recognition to video. Such extensions are typically trained for actions on single video frames or very short clips, and then their predictions from sliding-windows over the video sequence are pooled for recognizing the action at the sequence level. Usually this pooling step uses the first-order statistics of frame-level action predictions. In this paper, we explore the advantages of using higher-order correlations; specifically, we introduce Higher-order Kernel (HOK) descriptors generated from the late fusion of CNN classifier scores from all the frames in a sequence. To generate these descriptors, we use the idea of kernel linearization. Specifically, a similarity kernel matrix, which captures the temporal evolution of deep classifier scores, is first linearized into kernel feature maps. The HOK descriptors are then generated from the higher-order co-occurrences of these feature maps, and are then used as input to a video-level classifier. We provide experiments on two fine-grained action recognition datasets and show that our scheme leads to state-of-the-art results.
[ { "version": "v1", "created": "Thu, 19 Jan 2017 14:30:49 GMT" } ]
2017-01-20T00:00:00
[ [ "Cherian", "Anoop", "" ], [ "Koniusz", "Piotr", "" ], [ "Gould", "Stephen", "" ] ]
TITLE: Higher-order Pooling of CNN Features via Kernel Linearization for Action Recognition ABSTRACT: Most successful deep learning algorithms for action recognition extend models designed for image-based tasks such as object recognition to video. Such extensions are typically trained for actions on single video frames or very short clips, and then their predictions from sliding-windows over the video sequence are pooled for recognizing the action at the sequence level. Usually this pooling step uses the first-order statistics of frame-level action predictions. In this paper, we explore the advantages of using higher-order correlations; specifically, we introduce Higher-order Kernel (HOK) descriptors generated from the late fusion of CNN classifier scores from all the frames in a sequence. To generate these descriptors, we use the idea of kernel linearization. Specifically, a similarity kernel matrix, which captures the temporal evolution of deep classifier scores, is first linearized into kernel feature maps. The HOK descriptors are then generated from the higher-order co-occurrences of these feature maps, and are then used as input to a video-level classifier. We provide experiments on two fine-grained action recognition datasets and show that our scheme leads to state-of-the-art results.
no_new_dataset
0.95222
1701.05449
Jerome Darmont
Varunya Attasena (ERIC), Nouria Harbi (ERIC), J\'er\^ome Darmont (ERIC)
A Novel Multi-Secret Sharing Approach for Secure Data Warehousing and On-Line Analysis Processing in the Cloud
null
International Journal of Data Warehousing and Mining, 11 (2), pp.22 - 43 (2015)
10.4018/ijdwm.2015040102
null
cs.DB cs.CR
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Cloud computing helps reduce costs, increase business agility and deploy solutions with a high return on investment for many types of applications, including data warehouses and on-line analytical processing. However, storing and transferring sensitive data into the cloud raises legitimate security concerns. In this paper, we propose a new multi-secret sharing approach for deploying data warehouses in the cloud and allowing on-line analysis processing, while enforcing data privacy, integrity and availability. We first validate the relevance of our approach theoretically and then experimentally with both a simple random dataset and the Star Schema Benchmark. We also demonstrate its superiority to related methods.
[ { "version": "v1", "created": "Thu, 19 Jan 2017 14:54:21 GMT" } ]
2017-01-20T00:00:00
[ [ "Attasena", "Varunya", "", "ERIC" ], [ "Harbi", "Nouria", "", "ERIC" ], [ "Darmont", "Jérôme", "", "ERIC" ] ]
TITLE: A Novel Multi-Secret Sharing Approach for Secure Data Warehousing and On-Line Analysis Processing in the Cloud ABSTRACT: Cloud computing helps reduce costs, increase business agility and deploy solutions with a high return on investment for many types of applications, including data warehouses and on-line analytical processing. However, storing and transferring sensitive data into the cloud raises legitimate security concerns. In this paper, we propose a new multi-secret sharing approach for deploying data warehouses in the cloud and allowing on-line analysis processing, while enforcing data privacy, integrity and availability. We first validate the relevance of our approach theoretically and then experimentally with both a simple random dataset and the Star Schema Benchmark. We also demonstrate its superiority to related methods.
no_new_dataset
0.949716
1701.05498
Tomas Hodan
Tomas Hodan, Pavel Haluza, Stepan Obdrzalek, Jiri Matas, Manolis Lourakis, Xenophon Zabulis
T-LESS: An RGB-D Dataset for 6D Pose Estimation of Texture-less Objects
WACV 2017
null
null
null
cs.CV cs.AI cs.RO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We introduce T-LESS, a new public dataset for estimating the 6D pose, i.e. translation and rotation, of texture-less rigid objects. The dataset features thirty industry-relevant objects with no significant texture and no discriminative color or reflectance properties. The objects exhibit symmetries and mutual similarities in shape and/or size. Compared to other datasets, a unique property is that some of the objects are parts of others. The dataset includes training and test images that were captured with three synchronized sensors, specifically a structured-light and a time-of-flight RGB-D sensor and a high-resolution RGB camera. There are approximately 39K training and 10K test images from each sensor. Additionally, two types of 3D models are provided for each object, i.e. a manually created CAD model and a semi-automatically reconstructed one. Training images depict individual objects against a black background. Test images originate from twenty test scenes having varying complexity, which increases from simple scenes with several isolated objects to very challenging ones with multiple instances of several objects and with a high amount of clutter and occlusion. The images were captured from a systematically sampled view sphere around the object/scene, and are annotated with accurate ground truth 6D poses of all modeled objects. Initial evaluation results indicate that the state of the art in 6D object pose estimation has ample room for improvement, especially in difficult cases with significant occlusion. The T-LESS dataset is available online at cmp.felk.cvut.cz/t-less.
[ { "version": "v1", "created": "Thu, 19 Jan 2017 16:16:36 GMT" } ]
2017-01-20T00:00:00
[ [ "Hodan", "Tomas", "" ], [ "Haluza", "Pavel", "" ], [ "Obdrzalek", "Stepan", "" ], [ "Matas", "Jiri", "" ], [ "Lourakis", "Manolis", "" ], [ "Zabulis", "Xenophon", "" ] ]
TITLE: T-LESS: An RGB-D Dataset for 6D Pose Estimation of Texture-less Objects ABSTRACT: We introduce T-LESS, a new public dataset for estimating the 6D pose, i.e. translation and rotation, of texture-less rigid objects. The dataset features thirty industry-relevant objects with no significant texture and no discriminative color or reflectance properties. The objects exhibit symmetries and mutual similarities in shape and/or size. Compared to other datasets, a unique property is that some of the objects are parts of others. The dataset includes training and test images that were captured with three synchronized sensors, specifically a structured-light and a time-of-flight RGB-D sensor and a high-resolution RGB camera. There are approximately 39K training and 10K test images from each sensor. Additionally, two types of 3D models are provided for each object, i.e. a manually created CAD model and a semi-automatically reconstructed one. Training images depict individual objects against a black background. Test images originate from twenty test scenes having varying complexity, which increases from simple scenes with several isolated objects to very challenging ones with multiple instances of several objects and with a high amount of clutter and occlusion. The images were captured from a systematically sampled view sphere around the object/scene, and are annotated with accurate ground truth 6D poses of all modeled objects. Initial evaluation results indicate that the state of the art in 6D object pose estimation has ample room for improvement, especially in difficult cases with significant occlusion. The T-LESS dataset is available online at cmp.felk.cvut.cz/t-less.
new_dataset
0.968381
1604.05417
Swami Sankaranarayanan
Swami Sankaranarayanan, Azadeh Alavi, Carlos Castillo, Rama Chellappa
Triplet Probabilistic Embedding for Face Verification and Clustering
Oral Paper in BTAS 2016; NVIDIA Best paper Award (http://ieee-biometrics.org/btas2016/awards.html)
null
10.1109/BTAS.2016.7791205
null
cs.CV cs.LG stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Despite significant progress made over the past twenty five years, unconstrained face verification remains a challenging problem. This paper proposes an approach that couples a deep CNN-based approach with a low-dimensional discriminative embedding learned using triplet probability constraints to solve the unconstrained face verification problem. Aside from yielding performance improvements, this embedding provides significant advantages in terms of memory and for post-processing operations like subject specific clustering. Experiments on the challenging IJB-A dataset show that the proposed algorithm performs comparably or better than the state of the art methods in verification and identification metrics, while requiring much less training data and training time. The superior performance of the proposed method on the CFP dataset shows that the representation learned by our deep CNN is robust to extreme pose variation. Furthermore, we demonstrate the robustness of the deep features to challenges including age, pose, blur and clutter by performing simple clustering experiments on both IJB-A and LFW datasets.
[ { "version": "v1", "created": "Tue, 19 Apr 2016 03:29:56 GMT" }, { "version": "v2", "created": "Sun, 8 May 2016 16:04:02 GMT" }, { "version": "v3", "created": "Wed, 18 Jan 2017 03:10:44 GMT" } ]
2017-01-19T00:00:00
[ [ "Sankaranarayanan", "Swami", "" ], [ "Alavi", "Azadeh", "" ], [ "Castillo", "Carlos", "" ], [ "Chellappa", "Rama", "" ] ]
TITLE: Triplet Probabilistic Embedding for Face Verification and Clustering ABSTRACT: Despite significant progress made over the past twenty five years, unconstrained face verification remains a challenging problem. This paper proposes an approach that couples a deep CNN-based approach with a low-dimensional discriminative embedding learned using triplet probability constraints to solve the unconstrained face verification problem. Aside from yielding performance improvements, this embedding provides significant advantages in terms of memory and for post-processing operations like subject specific clustering. Experiments on the challenging IJB-A dataset show that the proposed algorithm performs comparably or better than the state of the art methods in verification and identification metrics, while requiring much less training data and training time. The superior performance of the proposed method on the CFP dataset shows that the representation learned by our deep CNN is robust to extreme pose variation. Furthermore, we demonstrate the robustness of the deep features to challenges including age, pose, blur and clutter by performing simple clustering experiments on both IJB-A and LFW datasets.
no_new_dataset
0.949153
1701.04819
Primoz Kajdic
P. Kajdic, O. Alexandrova, M. Maksimovic, C. Lacombe and A. N. Fazakerley
Suprathermal electron strahl widths in the presence of narrow-band whistler waves in the solar wind
Published in ApJ
Kajdic et al., TheApJ, 833, 172, 2016
10.3847/1538-4357/833/2/172
null
physics.space-ph astro-ph.EP
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We perform the first statistical study of the effects of the interaction of suprathermal electrons with narrow-band whistler mode waves in the solar wind. We show that this interaction does occur and that it is associated with enhanced widths of the so called strahl component. The latter is directed along the inter- planetary magnetic field away from the Sun. We do the study by comparing the strahl pitch angle widths in the solar wind at 1AU in the absence of large scale discontinuities and transient structures, such as interplanetary shocks, interplanetary coronal mass ejections, stream interaction regions, etc. during times when the whistler mode waves were present and when they were absent. This is done by using the data from two Cluster instruments: STAFF data in frequency range between ~0.1 Hz and ~200 Hz were used for determining the wave properties and PEACE datasets at twelve central energies between ~57 eV (equivalent to ~10 typical electron thermal energies in the solar wind, E_T ) and ~676 eV (~113 E_T ) for pitch angle measurements. Statistical analysis shows that during the inter- vals with the whistler waves the strahl component on average exhibits pitch angle widths between 2 and 12 degrees larger than during the intervals when these waves are not present. The largest difference is obtained for the electron central energy of ~344 eV (~57 E_T ).
[ { "version": "v1", "created": "Tue, 17 Jan 2017 17:12:01 GMT" } ]
2017-01-19T00:00:00
[ [ "Kajdic", "P.", "" ], [ "Alexandrova", "O.", "" ], [ "Maksimovic", "M.", "" ], [ "Lacombe", "C.", "" ], [ "Fazakerley", "A. N.", "" ] ]
TITLE: Suprathermal electron strahl widths in the presence of narrow-band whistler waves in the solar wind ABSTRACT: We perform the first statistical study of the effects of the interaction of suprathermal electrons with narrow-band whistler mode waves in the solar wind. We show that this interaction does occur and that it is associated with enhanced widths of the so called strahl component. The latter is directed along the inter- planetary magnetic field away from the Sun. We do the study by comparing the strahl pitch angle widths in the solar wind at 1AU in the absence of large scale discontinuities and transient structures, such as interplanetary shocks, interplanetary coronal mass ejections, stream interaction regions, etc. during times when the whistler mode waves were present and when they were absent. This is done by using the data from two Cluster instruments: STAFF data in frequency range between ~0.1 Hz and ~200 Hz were used for determining the wave properties and PEACE datasets at twelve central energies between ~57 eV (equivalent to ~10 typical electron thermal energies in the solar wind, E_T ) and ~676 eV (~113 E_T ) for pitch angle measurements. Statistical analysis shows that during the inter- vals with the whistler waves the strahl component on average exhibits pitch angle widths between 2 and 12 degrees larger than during the intervals when these waves are not present. The largest difference is obtained for the electron central energy of ~344 eV (~57 E_T ).
no_new_dataset
0.946892
1701.04934
Swati Agarwal
Swati Agarwal and Ashish Sureka
Investigating the Application of Common-Sense Knowledge-Base for Identifying Term Obfuscation in Adversarial Communication
This paper is an extended and detailed version of our (same authors) previous paper (regular paper) published at COMSNETS2015
S. Agarwal and A. Sureka, "Using common-sense knowledge-base for detecting word obfuscation in adversarial communication," 2015 7th International Conference on Communication Systems and Networks (COMSNETS), Bangalore, 2015, pp. 1-6
null
null
cs.IR
http://creativecommons.org/licenses/by/4.0/
Word obfuscation or substitution means replacing one word with another word in a sentence to conceal the textual content or communication. Word obfuscation is used in adversarial communication by terrorist or criminals for conveying their messages without getting red-flagged by security and intelligence agencies intercepting or scanning messages (such as emails and telephone conversations). ConceptNet is a freely available semantic network represented as a directed graph consisting of nodes as concepts and edges as assertions of common sense about these concepts. We present a solution approach exploiting vast amount of semantic knowledge in ConceptNet for addressing the technically challenging problem of word substitution in adversarial communication. We frame the given problem as a textual reasoning and context inference task and utilize ConceptNet's natural-language-processing tool-kit for determining word substitution. We use ConceptNet to compute the conceptual similarity between any two given terms and define a Mean Average Conceptual Similarity (MACS) metric to identify out-of-context terms. The test-bed to evaluate our proposed approach consists of Enron email dataset (having over 600000 emails generated by 158 employees of Enron Corporation) and Brown corpus (totaling about a million words drawn from a wide variety of sources). We implement word substitution techniques used by previous researches to generate a test dataset. We conduct a series of experiments consisting of word substitution methods used in the past to evaluate our approach. Experimental results reveal that the proposed approach is effective.
[ { "version": "v1", "created": "Wed, 18 Jan 2017 03:36:33 GMT" } ]
2017-01-19T00:00:00
[ [ "Agarwal", "Swati", "" ], [ "Sureka", "Ashish", "" ] ]
TITLE: Investigating the Application of Common-Sense Knowledge-Base for Identifying Term Obfuscation in Adversarial Communication ABSTRACT: Word obfuscation or substitution means replacing one word with another word in a sentence to conceal the textual content or communication. Word obfuscation is used in adversarial communication by terrorist or criminals for conveying their messages without getting red-flagged by security and intelligence agencies intercepting or scanning messages (such as emails and telephone conversations). ConceptNet is a freely available semantic network represented as a directed graph consisting of nodes as concepts and edges as assertions of common sense about these concepts. We present a solution approach exploiting vast amount of semantic knowledge in ConceptNet for addressing the technically challenging problem of word substitution in adversarial communication. We frame the given problem as a textual reasoning and context inference task and utilize ConceptNet's natural-language-processing tool-kit for determining word substitution. We use ConceptNet to compute the conceptual similarity between any two given terms and define a Mean Average Conceptual Similarity (MACS) metric to identify out-of-context terms. The test-bed to evaluate our proposed approach consists of Enron email dataset (having over 600000 emails generated by 158 employees of Enron Corporation) and Brown corpus (totaling about a million words drawn from a wide variety of sources). We implement word substitution techniques used by previous researches to generate a test dataset. We conduct a series of experiments consisting of word substitution methods used in the past to evaluate our approach. Experimental results reveal that the proposed approach is effective.
new_dataset
0.960175
1701.04949
Volodymyr Turchenko
Volodymyr Turchenko, Eric Chalmers, Artur Luczak
A Deep Convolutional Auto-Encoder with Pooling - Unpooling Layers in Caffe
21 pages, 11 figures, 5 tables, 62 references
null
null
null
cs.NE cs.CV cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper presents the development of several models of a deep convolutional auto-encoder in the Caffe deep learning framework and their experimental evaluation on the example of MNIST dataset. We have created five models of a convolutional auto-encoder which differ architecturally by the presence or absence of pooling and unpooling layers in the auto-encoder's encoder and decoder parts. Our results show that the developed models provide very good results in dimensionality reduction and unsupervised clustering tasks, and small classification errors when we used the learned internal code as an input of a supervised linear classifier and multi-layer perceptron. The best results were provided by a model where the encoder part contains convolutional and pooling layers, followed by an analogous decoder part with deconvolution and unpooling layers without the use of switch variables in the decoder part. The paper also discusses practical details of the creation of a deep convolutional auto-encoder in the very popular Caffe deep learning framework. We believe that our approach and results presented in this paper could help other researchers to build efficient deep neural network architectures in the future.
[ { "version": "v1", "created": "Wed, 18 Jan 2017 05:24:24 GMT" } ]
2017-01-19T00:00:00
[ [ "Turchenko", "Volodymyr", "" ], [ "Chalmers", "Eric", "" ], [ "Luczak", "Artur", "" ] ]
TITLE: A Deep Convolutional Auto-Encoder with Pooling - Unpooling Layers in Caffe ABSTRACT: This paper presents the development of several models of a deep convolutional auto-encoder in the Caffe deep learning framework and their experimental evaluation on the example of MNIST dataset. We have created five models of a convolutional auto-encoder which differ architecturally by the presence or absence of pooling and unpooling layers in the auto-encoder's encoder and decoder parts. Our results show that the developed models provide very good results in dimensionality reduction and unsupervised clustering tasks, and small classification errors when we used the learned internal code as an input of a supervised linear classifier and multi-layer perceptron. The best results were provided by a model where the encoder part contains convolutional and pooling layers, followed by an analogous decoder part with deconvolution and unpooling layers without the use of switch variables in the decoder part. The paper also discusses practical details of the creation of a deep convolutional auto-encoder in the very popular Caffe deep learning framework. We believe that our approach and results presented in this paper could help other researchers to build efficient deep neural network architectures in the future.
no_new_dataset
0.950365
1701.05149
G\"urkan Alpaslan
G\"urkan Alpaslan
Comparison of the Efficiency of Different Algorithms on Recommendation System Design: a Case Study
null
null
null
null
cs.IR
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
By the growing trend of online shopping and e-commerce websites, recommendation systems have gained more importance in recent years in order to increase the sales ratios of companies. Different algorithms on recommendation systems are used and every one produce different results. Every algorithm on this area have positive and negative attributes. The purpose of the research is to test the different algorithms for choosing the best one according as structure of dataset and aims of developers. For this purpose, threshold and k-means based collaborative filtering and content-based filtering algorithms are utilized on the dataset contains 100*73421 matrix length. What are the differences and effects of these different algorithms on the same dataset? What are the challenges of the algorithms? What criteria are more important in order to evaluate a recommendation systems? In the study, we answer these crucial problems with the case study.
[ { "version": "v1", "created": "Sun, 1 Jan 2017 17:58:38 GMT" } ]
2017-01-19T00:00:00
[ [ "Alpaslan", "Gürkan", "" ] ]
TITLE: Comparison of the Efficiency of Different Algorithms on Recommendation System Design: a Case Study ABSTRACT: By the growing trend of online shopping and e-commerce websites, recommendation systems have gained more importance in recent years in order to increase the sales ratios of companies. Different algorithms on recommendation systems are used and every one produce different results. Every algorithm on this area have positive and negative attributes. The purpose of the research is to test the different algorithms for choosing the best one according as structure of dataset and aims of developers. For this purpose, threshold and k-means based collaborative filtering and content-based filtering algorithms are utilized on the dataset contains 100*73421 matrix length. What are the differences and effects of these different algorithms on the same dataset? What are the challenges of the algorithms? What criteria are more important in order to evaluate a recommendation systems? In the study, we answer these crucial problems with the case study.
no_new_dataset
0.950641
1605.03733
Riccardo Sven Risuleo
Riccardo Sven Risuleo and Giulio Bottegal and H{\aa}kan Hjalmarsson
Kernel-based system identification from noisy and incomplete input-output data
16 pages, submitted to IEEE Conference on Decision and Control 2016
null
10.1109/CDC.2016.7798567
null
cs.SY
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this contribution, we propose a kernel-based method for the identification of linear systems from noisy and incomplete input-output datasets. We model the impulse response of the system as a Gaussian process whose covariance matrix is given by the recently introduced stable spline kernel. We adopt an empirical Bayes approach to estimate the posterior distribution of the impulse response given the data. The noiseless and missing data samples, together with the kernel hyperparameters, are estimated maximizing the joint marginal likelihood of the input and output measurements. To compute the marginal-likelihood maximizer, we build a solution scheme based on the Expectation-Maximization method. Simulations on a benchmark dataset show the effectiveness of the method.
[ { "version": "v1", "created": "Thu, 12 May 2016 09:04:23 GMT" } ]
2017-01-18T00:00:00
[ [ "Risuleo", "Riccardo Sven", "" ], [ "Bottegal", "Giulio", "" ], [ "Hjalmarsson", "Håkan", "" ] ]
TITLE: Kernel-based system identification from noisy and incomplete input-output data ABSTRACT: In this contribution, we propose a kernel-based method for the identification of linear systems from noisy and incomplete input-output datasets. We model the impulse response of the system as a Gaussian process whose covariance matrix is given by the recently introduced stable spline kernel. We adopt an empirical Bayes approach to estimate the posterior distribution of the impulse response given the data. The noiseless and missing data samples, together with the kernel hyperparameters, are estimated maximizing the joint marginal likelihood of the input and output measurements. To compute the marginal-likelihood maximizer, we build a solution scheme based on the Expectation-Maximization method. Simulations on a benchmark dataset show the effectiveness of the method.
no_new_dataset
0.947769
1606.00305
Yang Li
Yang Li, Chunxiao Fan, Yong Li, Qiong Wu, Yue Ming
Improving Deep Neural Network with Multiple Parametric Exponential Linear Units
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Activation function is crucial to the recent successes of deep neural networks. In this paper, we first propose a new activation function, Multiple Parametric Exponential Linear Units (MPELU), aiming to generalize and unify the rectified and exponential linear units. As the generalized form, MPELU shares the advantages of Parametric Rectified Linear Unit (PReLU) and Exponential Linear Unit (ELU), leading to better classification performance and convergence property. In addition, weight initialization is very important to train very deep networks. The existing methods laid a solid foundation for networks using rectified linear units but not for exponential linear units. This paper complements the current theory and extends it to the wider range. Specifically, we put forward a way of initialization, enabling training of very deep networks using exponential linear units. Experiments demonstrate that the proposed initialization not only helps the training process but leads to better generalization performance. Finally, utilizing the proposed activation function and initialization, we present a deep MPELU residual architecture that achieves state-of-the-art performance on the CIFAR-10/100 datasets. The code is available at https://github.com/Coldmooon/Code-for-MPELU.
[ { "version": "v1", "created": "Wed, 1 Jun 2016 14:33:17 GMT" }, { "version": "v2", "created": "Tue, 9 Aug 2016 10:10:41 GMT" }, { "version": "v3", "created": "Tue, 17 Jan 2017 08:44:56 GMT" } ]
2017-01-18T00:00:00
[ [ "Li", "Yang", "" ], [ "Fan", "Chunxiao", "" ], [ "Li", "Yong", "" ], [ "Wu", "Qiong", "" ], [ "Ming", "Yue", "" ] ]
TITLE: Improving Deep Neural Network with Multiple Parametric Exponential Linear Units ABSTRACT: Activation function is crucial to the recent successes of deep neural networks. In this paper, we first propose a new activation function, Multiple Parametric Exponential Linear Units (MPELU), aiming to generalize and unify the rectified and exponential linear units. As the generalized form, MPELU shares the advantages of Parametric Rectified Linear Unit (PReLU) and Exponential Linear Unit (ELU), leading to better classification performance and convergence property. In addition, weight initialization is very important to train very deep networks. The existing methods laid a solid foundation for networks using rectified linear units but not for exponential linear units. This paper complements the current theory and extends it to the wider range. Specifically, we put forward a way of initialization, enabling training of very deep networks using exponential linear units. Experiments demonstrate that the proposed initialization not only helps the training process but leads to better generalization performance. Finally, utilizing the proposed activation function and initialization, we present a deep MPELU residual architecture that achieves state-of-the-art performance on the CIFAR-10/100 datasets. The code is available at https://github.com/Coldmooon/Code-for-MPELU.
no_new_dataset
0.952086
1610.05949
Raul Mur-Artal
Raul Mur-Artal and Juan D. Tardos
Visual-Inertial Monocular SLAM with Map Reuse
Accepted for publication in IEEE Robotics and Automation Letters
null
10.1109/LRA.2017.2653359
null
cs.RO cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In recent years there have been excellent results in Visual-Inertial Odometry techniques, which aim to compute the incremental motion of the sensor with high accuracy and robustness. However these approaches lack the capability to close loops, and trajectory estimation accumulates drift even if the sensor is continually revisiting the same place. In this work we present a novel tightly-coupled Visual-Inertial Simultaneous Localization and Mapping system that is able to close loops and reuse its map to achieve zero-drift localization in already mapped areas. While our approach can be applied to any camera configuration, we address here the most general problem of a monocular camera, with its well-known scale ambiguity. We also propose a novel IMU initialization method, which computes the scale, the gravity direction, the velocity, and gyroscope and accelerometer biases, in a few seconds with high accuracy. We test our system in the 11 sequences of a recent micro-aerial vehicle public dataset achieving a typical scale factor error of 1% and centimeter precision. We compare to the state-of-the-art in visual-inertial odometry in sequences with revisiting, proving the better accuracy of our method due to map reuse and no drift accumulation.
[ { "version": "v1", "created": "Wed, 19 Oct 2016 10:17:16 GMT" }, { "version": "v2", "created": "Tue, 17 Jan 2017 15:45:14 GMT" } ]
2017-01-18T00:00:00
[ [ "Mur-Artal", "Raul", "" ], [ "Tardos", "Juan D.", "" ] ]
TITLE: Visual-Inertial Monocular SLAM with Map Reuse ABSTRACT: In recent years there have been excellent results in Visual-Inertial Odometry techniques, which aim to compute the incremental motion of the sensor with high accuracy and robustness. However these approaches lack the capability to close loops, and trajectory estimation accumulates drift even if the sensor is continually revisiting the same place. In this work we present a novel tightly-coupled Visual-Inertial Simultaneous Localization and Mapping system that is able to close loops and reuse its map to achieve zero-drift localization in already mapped areas. While our approach can be applied to any camera configuration, we address here the most general problem of a monocular camera, with its well-known scale ambiguity. We also propose a novel IMU initialization method, which computes the scale, the gravity direction, the velocity, and gyroscope and accelerometer biases, in a few seconds with high accuracy. We test our system in the 11 sequences of a recent micro-aerial vehicle public dataset achieving a typical scale factor error of 1% and centimeter precision. We compare to the state-of-the-art in visual-inertial odometry in sequences with revisiting, proving the better accuracy of our method due to map reuse and no drift accumulation.
no_new_dataset
0.948298
1611.00303
Timothy O'Shea
Timothy J. O'Shea, Nathan West, Matthew Vondal, T. Charles Clancy
Semi-Supervised Radio Signal Identification
null
null
null
null
cs.LG cs.IT math.IT stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Radio emitter recognition in dense multi-user environments is an important tool for optimizing spectrum utilization, identifying and minimizing interference, and enforcing spectrum policy. Radio data is readily available and easy to obtain from an antenna, but labeled and curated data is often scarce making supervised learning strategies difficult and time consuming in practice. We demonstrate that semi-supervised learning techniques can be used to scale learning beyond supervised datasets, allowing for discerning and recalling new radio signals by using sparse signal representations based on both unsupervised and supervised methods for nonlinear feature learning and clustering methods.
[ { "version": "v1", "created": "Tue, 1 Nov 2016 17:21:50 GMT" }, { "version": "v2", "created": "Tue, 17 Jan 2017 18:23:49 GMT" } ]
2017-01-18T00:00:00
[ [ "O'Shea", "Timothy J.", "" ], [ "West", "Nathan", "" ], [ "Vondal", "Matthew", "" ], [ "Clancy", "T. Charles", "" ] ]
TITLE: Semi-Supervised Radio Signal Identification ABSTRACT: Radio emitter recognition in dense multi-user environments is an important tool for optimizing spectrum utilization, identifying and minimizing interference, and enforcing spectrum policy. Radio data is readily available and easy to obtain from an antenna, but labeled and curated data is often scarce making supervised learning strategies difficult and time consuming in practice. We demonstrate that semi-supervised learning techniques can be used to scale learning beyond supervised datasets, allowing for discerning and recalling new radio signals by using sparse signal representations based on both unsupervised and supervised methods for nonlinear feature learning and clustering methods.
no_new_dataset
0.949059
1612.00220
Mark Marsden
Mark Marsden, Kevin McGuinness, Suzanne Little, Noel E. O'Connor
Fully Convolutional Crowd Counting On Highly Congested Scenes
7 pages , VISAPP 2017
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we advance the state-of-the-art for crowd counting in high density scenes by further exploring the idea of a fully convolutional crowd counting model introduced by (Zhang et al., 2016). Producing an accurate and robust crowd count estimator using computer vision techniques has attracted significant research interest in recent years. Applications for crowd counting systems exist in many diverse areas including city planning, retail, and of course general public safety. Developing a highly generalised counting model that can be deployed in any surveillance scenario with any camera perspective is the key objective for research in this area. Techniques developed in the past have generally performed poorly in highly congested scenes with several thousands of people in frame (Rodriguez et al., 2011). Our approach, influenced by the work of (Zhang et al., 2016), consists of the following contributions: (1) A training set augmentation scheme that minimises redundancy among training samples to improve model generalisation and overall counting performance; (2) a deep, single column, fully convolutional network (FCN) architecture; (3) a multi-scale averaging step during inference. The developed technique can analyse images of any resolution or aspect ratio and achieves state-of-the-art counting performance on the Shanghaitech Part B and UCF CC 50 datasets as well as competitive performance on Shanghaitech Part A.
[ { "version": "v1", "created": "Thu, 1 Dec 2016 12:24:35 GMT" }, { "version": "v2", "created": "Tue, 17 Jan 2017 15:00:46 GMT" } ]
2017-01-18T00:00:00
[ [ "Marsden", "Mark", "" ], [ "McGuinness", "Kevin", "" ], [ "Little", "Suzanne", "" ], [ "O'Connor", "Noel E.", "" ] ]
TITLE: Fully Convolutional Crowd Counting On Highly Congested Scenes ABSTRACT: In this paper we advance the state-of-the-art for crowd counting in high density scenes by further exploring the idea of a fully convolutional crowd counting model introduced by (Zhang et al., 2016). Producing an accurate and robust crowd count estimator using computer vision techniques has attracted significant research interest in recent years. Applications for crowd counting systems exist in many diverse areas including city planning, retail, and of course general public safety. Developing a highly generalised counting model that can be deployed in any surveillance scenario with any camera perspective is the key objective for research in this area. Techniques developed in the past have generally performed poorly in highly congested scenes with several thousands of people in frame (Rodriguez et al., 2011). Our approach, influenced by the work of (Zhang et al., 2016), consists of the following contributions: (1) A training set augmentation scheme that minimises redundancy among training samples to improve model generalisation and overall counting performance; (2) a deep, single column, fully convolutional network (FCN) architecture; (3) a multi-scale averaging step during inference. The developed technique can analyse images of any resolution or aspect ratio and achieves state-of-the-art counting performance on the Shanghaitech Part B and UCF CC 50 datasets as well as competitive performance on Shanghaitech Part A.
no_new_dataset
0.952131
1701.04568
Mahesh Gorijala
Mahesh Gorijala, Ambedkar Dukkipati
Image Generation and Editing with Variational Info Generative AdversarialNetworks
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recently there has been an enormous interest in generative models for images in deep learning. In pursuit of this, Generative Adversarial Networks (GAN) and Variational Auto-Encoder (VAE) have surfaced as two most prominent and popular models. While VAEs tend to produce excellent reconstructions but blurry samples, GANs generate sharp but slightly distorted images. In this paper we propose a new model called Variational InfoGAN (ViGAN). Our aim is two fold: (i) To generated new images conditioned on visual descriptions, and (ii) modify the image, by fixing the latent representation of image and varying the visual description. We evaluate our model on Labeled Faces in the Wild (LFW), celebA and a modified version of MNIST datasets and demonstrate the ability of our model to generate new images as well as to modify a given image by changing attributes.
[ { "version": "v1", "created": "Tue, 17 Jan 2017 08:48:28 GMT" } ]
2017-01-18T00:00:00
[ [ "Gorijala", "Mahesh", "" ], [ "Dukkipati", "Ambedkar", "" ] ]
TITLE: Image Generation and Editing with Variational Info Generative AdversarialNetworks ABSTRACT: Recently there has been an enormous interest in generative models for images in deep learning. In pursuit of this, Generative Adversarial Networks (GAN) and Variational Auto-Encoder (VAE) have surfaced as two most prominent and popular models. While VAEs tend to produce excellent reconstructions but blurry samples, GANs generate sharp but slightly distorted images. In this paper we propose a new model called Variational InfoGAN (ViGAN). Our aim is two fold: (i) To generated new images conditioned on visual descriptions, and (ii) modify the image, by fixing the latent representation of image and varying the visual description. We evaluate our model on Labeled Faces in the Wild (LFW), celebA and a modified version of MNIST datasets and demonstrate the ability of our model to generate new images as well as to modify a given image by changing attributes.
no_new_dataset
0.951369
1701.04600
Amit Awekar
Siddhesh Khandelwal, Amit Awekar
Faster K-Means Cluster Estimation
6 pages, Accepted at ECIR 2017
null
null
null
cs.LG cs.IR
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
There has been considerable work on improving popular clustering algorithm `K-means' in terms of mean squared error (MSE) and speed, both. However, most of the k-means variants tend to compute distance of each data point to each cluster centroid for every iteration. We propose a fast heuristic to overcome this bottleneck with only marginal increase in MSE. We observe that across all iterations of K-means, a data point changes its membership only among a small subset of clusters. Our heuristic predicts such clusters for each data point by looking at nearby clusters after the first iteration of k-means. We augment well known variants of k-means with our heuristic to demonstrate effectiveness of our heuristic. For various synthetic and real-world datasets, our heuristic achieves speed-up of up-to 3 times when compared to efficient variants of k-means.
[ { "version": "v1", "created": "Tue, 17 Jan 2017 10:00:51 GMT" } ]
2017-01-18T00:00:00
[ [ "Khandelwal", "Siddhesh", "" ], [ "Awekar", "Amit", "" ] ]
TITLE: Faster K-Means Cluster Estimation ABSTRACT: There has been considerable work on improving popular clustering algorithm `K-means' in terms of mean squared error (MSE) and speed, both. However, most of the k-means variants tend to compute distance of each data point to each cluster centroid for every iteration. We propose a fast heuristic to overcome this bottleneck with only marginal increase in MSE. We observe that across all iterations of K-means, a data point changes its membership only among a small subset of clusters. Our heuristic predicts such clusters for each data point by looking at nearby clusters after the first iteration of k-means. We augment well known variants of k-means with our heuristic to demonstrate effectiveness of our heuristic. For various synthetic and real-world datasets, our heuristic achieves speed-up of up-to 3 times when compared to efficient variants of k-means.
no_new_dataset
0.945901
1701.04653
Marzieh Saeidi Marzieh Saeidi
Marzieh Saeidi, Alessandro Venerandi, Licia Capra and Sebastian Riedel
Community Question Answering Platforms vs. Twitter for Predicting Characteristics of Urban Neighbourhoods
Submitted to ICWSM2017
null
null
null
cs.CL cs.SI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we investigate whether text from a Community Question Answering (QA) platform can be used to predict and describe real-world attributes. We experiment with predicting a wide range of 62 demographic attributes for neighbourhoods of London. We use the text from QA platform of Yahoo! Answers and compare our results to the ones obtained from Twitter microblogs. Outcomes show that the correlation between the predicted demographic attributes using text from Yahoo! Answers discussions and the observed demographic attributes can reach an average Pearson correlation coefficient of \r{ho} = 0.54, slightly higher than the predictions obtained using Twitter data. Our qualitative analysis indicates that there is semantic relatedness between the highest correlated terms extracted from both datasets and their relative demographic attributes. Furthermore, the correlations highlight the different natures of the information contained in Yahoo! Answers and Twitter. While the former seems to offer a more encyclopedic content, the latter provides information related to the current sociocultural aspects or phenomena.
[ { "version": "v1", "created": "Tue, 17 Jan 2017 12:53:19 GMT" } ]
2017-01-18T00:00:00
[ [ "Saeidi", "Marzieh", "" ], [ "Venerandi", "Alessandro", "" ], [ "Capra", "Licia", "" ], [ "Riedel", "Sebastian", "" ] ]
TITLE: Community Question Answering Platforms vs. Twitter for Predicting Characteristics of Urban Neighbourhoods ABSTRACT: In this paper, we investigate whether text from a Community Question Answering (QA) platform can be used to predict and describe real-world attributes. We experiment with predicting a wide range of 62 demographic attributes for neighbourhoods of London. We use the text from QA platform of Yahoo! Answers and compare our results to the ones obtained from Twitter microblogs. Outcomes show that the correlation between the predicted demographic attributes using text from Yahoo! Answers discussions and the observed demographic attributes can reach an average Pearson correlation coefficient of \r{ho} = 0.54, slightly higher than the predictions obtained using Twitter data. Our qualitative analysis indicates that there is semantic relatedness between the highest correlated terms extracted from both datasets and their relative demographic attributes. Furthermore, the correlations highlight the different natures of the information contained in Yahoo! Answers and Twitter. While the former seems to offer a more encyclopedic content, the latter provides information related to the current sociocultural aspects or phenomena.
no_new_dataset
0.953101
1701.04693
Sepehr Valipour
Sepehr Valipour, Camilo Perez, Martin Jagersand
Incremental Learning for Robot Perception through HRI
null
null
null
null
cs.RO cs.HC cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Scene understanding and object recognition is a difficult to achieve yet crucial skill for robots. Recently, Convolutional Neural Networks (CNN), have shown success in this task. However, there is still a gap between their performance on image datasets and real-world robotics scenarios. We present a novel paradigm for incrementally improving a robot's visual perception through active human interaction. In this paradigm, the user introduces novel objects to the robot by means of pointing and voice commands. Given this information, the robot visually explores the object and adds images from it to re-train the perception module. Our base perception module is based on recent development in object detection and recognition using deep learning. Our method leverages state of the art CNNs from off-line batch learning, human guidance, robot exploration and incremental on-line learning.
[ { "version": "v1", "created": "Tue, 17 Jan 2017 14:29:05 GMT" } ]
2017-01-18T00:00:00
[ [ "Valipour", "Sepehr", "" ], [ "Perez", "Camilo", "" ], [ "Jagersand", "Martin", "" ] ]
TITLE: Incremental Learning for Robot Perception through HRI ABSTRACT: Scene understanding and object recognition is a difficult to achieve yet crucial skill for robots. Recently, Convolutional Neural Networks (CNN), have shown success in this task. However, there is still a gap between their performance on image datasets and real-world robotics scenarios. We present a novel paradigm for incrementally improving a robot's visual perception through active human interaction. In this paradigm, the user introduces novel objects to the robot by means of pointing and voice commands. Given this information, the robot visually explores the object and adds images from it to re-train the perception module. Our base perception module is based on recent development in object detection and recognition using deep learning. Our method leverages state of the art CNNs from off-line batch learning, human guidance, robot exploration and incremental on-line learning.
no_new_dataset
0.950273
1701.04769
Unaiza Ahsan
Unaiza Ahsan, Chen Sun, James Hays and Irfan Essa
Complex Event Recognition from Images with Few Training Examples
Accepted to Winter Applications of Computer Vision (WACV'17)
null
null
null
cs.CV
http://creativecommons.org/licenses/by/4.0/
We propose to leverage concept-level representations for complex event recognition in photographs given limited training examples. We introduce a novel framework to discover event concept attributes from the web and use that to extract semantic features from images and classify them into social event categories with few training examples. Discovered concepts include a variety of objects, scenes, actions and event sub-types, leading to a discriminative and compact representation for event images. Web images are obtained for each discovered event concept and we use (pretrained) CNN features to train concept classifiers. Extensive experiments on challenging event datasets demonstrate that our proposed method outperforms several baselines using deep CNN features directly in classifying images into events with limited training examples. We also demonstrate that our method achieves the best overall accuracy on a dataset with unseen event categories using a single training example.
[ { "version": "v1", "created": "Tue, 17 Jan 2017 17:16:55 GMT" } ]
2017-01-18T00:00:00
[ [ "Ahsan", "Unaiza", "" ], [ "Sun", "Chen", "" ], [ "Hays", "James", "" ], [ "Essa", "Irfan", "" ] ]
TITLE: Complex Event Recognition from Images with Few Training Examples ABSTRACT: We propose to leverage concept-level representations for complex event recognition in photographs given limited training examples. We introduce a novel framework to discover event concept attributes from the web and use that to extract semantic features from images and classify them into social event categories with few training examples. Discovered concepts include a variety of objects, scenes, actions and event sub-types, leading to a discriminative and compact representation for event images. Web images are obtained for each discovered event concept and we use (pretrained) CNN features to train concept classifiers. Extensive experiments on challenging event datasets demonstrate that our proposed method outperforms several baselines using deep CNN features directly in classifying images into events with limited training examples. We also demonstrate that our method achieves the best overall accuracy on a dataset with unseen event categories using a single training example.
no_new_dataset
0.950915
1701.04783
Lei Zheng
Lei Zheng, Vahid Noroozi, Philip S. Yu
Joint Deep Modeling of Users and Items Using Reviews for Recommendation
WSDM 2017
null
null
null
cs.LG cs.IR
http://creativecommons.org/licenses/by/4.0/
A large amount of information exists in reviews written by users. This source of information has been ignored by most of the current recommender systems while it can potentially alleviate the sparsity problem and improve the quality of recommendations. In this paper, we present a deep model to learn item properties and user behaviors jointly from review text. The proposed model, named Deep Cooperative Neural Networks (DeepCoNN), consists of two parallel neural networks coupled in the last layers. One of the networks focuses on learning user behaviors exploiting reviews written by the user, and the other one learns item properties from the reviews written for the item. A shared layer is introduced on the top to couple these two networks together. The shared layer enables latent factors learned for users and items to interact with each other in a manner similar to factorization machine techniques. Experimental results demonstrate that DeepCoNN significantly outperforms all baseline recommender systems on a variety of datasets.
[ { "version": "v1", "created": "Tue, 17 Jan 2017 17:46:04 GMT" } ]
2017-01-18T00:00:00
[ [ "Zheng", "Lei", "" ], [ "Noroozi", "Vahid", "" ], [ "Yu", "Philip S.", "" ] ]
TITLE: Joint Deep Modeling of Users and Items Using Reviews for Recommendation ABSTRACT: A large amount of information exists in reviews written by users. This source of information has been ignored by most of the current recommender systems while it can potentially alleviate the sparsity problem and improve the quality of recommendations. In this paper, we present a deep model to learn item properties and user behaviors jointly from review text. The proposed model, named Deep Cooperative Neural Networks (DeepCoNN), consists of two parallel neural networks coupled in the last layers. One of the networks focuses on learning user behaviors exploiting reviews written by the user, and the other one learns item properties from the reviews written for the item. A shared layer is introduced on the top to couple these two networks together. The shared layer enables latent factors learned for users and items to interact with each other in a manner similar to factorization machine techniques. Experimental results demonstrate that DeepCoNN significantly outperforms all baseline recommender systems on a variety of datasets.
no_new_dataset
0.950732
1606.00511
Xi He
Xi He and Dheevatsa Mudigere and Mikhail Smelyanskiy and Martin Tak\'a\v{c}
Distributed Hessian-Free Optimization for Deep Neural Network
null
null
null
null
cs.LG cs.DC math.OC
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Training deep neural network is a high dimensional and a highly non-convex optimization problem. Stochastic gradient descent (SGD) algorithm and it's variations are the current state-of-the-art solvers for this task. However, due to non-covexity nature of the problem, it was observed that SGD slows down near saddle point. Recent empirical work claim that by detecting and escaping saddle point efficiently, it's more likely to improve training performance. With this objective, we revisit Hessian-free optimization method for deep networks. We also develop its distributed variant and demonstrate superior scaling potential to SGD, which allows more efficiently utilizing larger computing resources thus enabling large models and faster time to obtain desired solution. Furthermore, unlike truncated Newton method (Marten's HF) that ignores negative curvature information by using na\"ive conjugate gradient method and Gauss-Newton Hessian approximation information - we propose a novel algorithm to explore negative curvature direction by solving the sub-problem with stabilized bi-conjugate method involving possible indefinite stochastic Hessian information. We show that these techniques accelerate the training process for both the standard MNIST dataset and also the TIMIT speech recognition problem, demonstrating robust performance with upto an order of magnitude larger batch sizes. This increased scaling potential is illustrated with near linear speed-up on upto 16 CPU nodes for a simple 4-layer network.
[ { "version": "v1", "created": "Thu, 2 Jun 2016 00:39:03 GMT" }, { "version": "v2", "created": "Sun, 15 Jan 2017 13:51:26 GMT" } ]
2017-01-17T00:00:00
[ [ "He", "Xi", "" ], [ "Mudigere", "Dheevatsa", "" ], [ "Smelyanskiy", "Mikhail", "" ], [ "Takáč", "Martin", "" ] ]
TITLE: Distributed Hessian-Free Optimization for Deep Neural Network ABSTRACT: Training deep neural network is a high dimensional and a highly non-convex optimization problem. Stochastic gradient descent (SGD) algorithm and it's variations are the current state-of-the-art solvers for this task. However, due to non-covexity nature of the problem, it was observed that SGD slows down near saddle point. Recent empirical work claim that by detecting and escaping saddle point efficiently, it's more likely to improve training performance. With this objective, we revisit Hessian-free optimization method for deep networks. We also develop its distributed variant and demonstrate superior scaling potential to SGD, which allows more efficiently utilizing larger computing resources thus enabling large models and faster time to obtain desired solution. Furthermore, unlike truncated Newton method (Marten's HF) that ignores negative curvature information by using na\"ive conjugate gradient method and Gauss-Newton Hessian approximation information - we propose a novel algorithm to explore negative curvature direction by solving the sub-problem with stabilized bi-conjugate method involving possible indefinite stochastic Hessian information. We show that these techniques accelerate the training process for both the standard MNIST dataset and also the TIMIT speech recognition problem, demonstrating robust performance with upto an order of magnitude larger batch sizes. This increased scaling potential is illustrated with near linear speed-up on upto 16 CPU nodes for a simple 4-layer network.
no_new_dataset
0.945851
1608.00486
Conrad Sanderson
ZongYuan Ge, Chris McCool, Conrad Sanderson, Peng Wang, Lingqiao Liu, Ian Reid, Peter Corke
Exploiting Temporal Information for DCNN-based Fine-Grained Object Classification
International Conference on Digital Image Computing: Techniques and Applications, 2016
null
10.1109/DICTA.2016.7797039
null
cs.CV cs.MM
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Fine-grained classification is a relatively new field that has concentrated on using information from a single image, while ignoring the enormous potential of using video data to improve classification. In this work we present the novel task of video-based fine-grained object classification, propose a corresponding new video dataset, and perform a systematic study of several recent deep convolutional neural network (DCNN) based approaches, which we specifically adapt to the task. We evaluate three-dimensional DCNNs, two-stream DCNNs, and bilinear DCNNs. Two forms of the two-stream approach are used, where spatial and temporal data from two independent DCNNs are fused either via early fusion (combination of the fully-connected layers) and late fusion (concatenation of the softmax outputs of the DCNNs). For bilinear DCNNs, information from the convolutional layers of the spatial and temporal DCNNs is combined via local co-occurrences. We then fuse the bilinear DCNN and early fusion of the two-stream approach to combine the spatial and temporal information at the local and global level (Spatio-Temporal Co-occurrence). Using the new and challenging video dataset of birds, classification performance is improved from 23.1% (using single images) to 41.1% when using the Spatio-Temporal Co-occurrence system. Incorporating automatically detected bounding box location further improves the classification accuracy to 53.6%.
[ { "version": "v1", "created": "Mon, 1 Aug 2016 16:34:16 GMT" }, { "version": "v2", "created": "Wed, 31 Aug 2016 01:23:47 GMT" }, { "version": "v3", "created": "Mon, 24 Oct 2016 06:40:02 GMT" } ]
2017-01-17T00:00:00
[ [ "Ge", "ZongYuan", "" ], [ "McCool", "Chris", "" ], [ "Sanderson", "Conrad", "" ], [ "Wang", "Peng", "" ], [ "Liu", "Lingqiao", "" ], [ "Reid", "Ian", "" ], [ "Corke", "Peter", "" ] ]
TITLE: Exploiting Temporal Information for DCNN-based Fine-Grained Object Classification ABSTRACT: Fine-grained classification is a relatively new field that has concentrated on using information from a single image, while ignoring the enormous potential of using video data to improve classification. In this work we present the novel task of video-based fine-grained object classification, propose a corresponding new video dataset, and perform a systematic study of several recent deep convolutional neural network (DCNN) based approaches, which we specifically adapt to the task. We evaluate three-dimensional DCNNs, two-stream DCNNs, and bilinear DCNNs. Two forms of the two-stream approach are used, where spatial and temporal data from two independent DCNNs are fused either via early fusion (combination of the fully-connected layers) and late fusion (concatenation of the softmax outputs of the DCNNs). For bilinear DCNNs, information from the convolutional layers of the spatial and temporal DCNNs is combined via local co-occurrences. We then fuse the bilinear DCNN and early fusion of the two-stream approach to combine the spatial and temporal information at the local and global level (Spatio-Temporal Co-occurrence). Using the new and challenging video dataset of birds, classification performance is improved from 23.1% (using single images) to 41.1% when using the Spatio-Temporal Co-occurrence system. Incorporating automatically detected bounding box location further improves the classification accuracy to 53.6%.
no_new_dataset
0.952618
1608.06770
Emanuele Sansone
E. Sansone, K. Apostolidis, N. Conci, G. Boato, V. Mezaris, F.G.B. De Natale
Automatic Synchronization of Multi-User Photo Galleries
ACCEPTED to IEEE Transactions on Multimedia
null
null
null
cs.MM cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we address the issue of photo galleries synchronization, where pictures related to the same event are collected by different users. Existing solutions to address the problem are usually based on unrealistic assumptions, like time consistency across photo galleries, and often heavily rely on heuristics, limiting therefore the applicability to real-world scenarios. We propose a solution that achieves better generalization performance for the synchronization task compared to the available literature. The method is characterized by three stages: at first, deep convolutional neural network features are used to assess the visual similarity among the photos; then, pairs of similar photos are detected across different galleries and used to construct a graph; eventually, a probabilistic graphical model is used to estimate the temporal offset of each pair of galleries, by traversing the minimum spanning tree extracted from this graph. The experimental evaluation is conducted on four publicly available datasets covering different types of events, demonstrating the strength of our proposed method. A thorough discussion of the obtained results is provided for a critical assessment of the quality in synchronization.
[ { "version": "v1", "created": "Wed, 24 Aug 2016 10:17:16 GMT" }, { "version": "v2", "created": "Mon, 16 Jan 2017 11:19:49 GMT" } ]
2017-01-17T00:00:00
[ [ "Sansone", "E.", "" ], [ "Apostolidis", "K.", "" ], [ "Conci", "N.", "" ], [ "Boato", "G.", "" ], [ "Mezaris", "V.", "" ], [ "De Natale", "F. G. B.", "" ] ]
TITLE: Automatic Synchronization of Multi-User Photo Galleries ABSTRACT: In this paper we address the issue of photo galleries synchronization, where pictures related to the same event are collected by different users. Existing solutions to address the problem are usually based on unrealistic assumptions, like time consistency across photo galleries, and often heavily rely on heuristics, limiting therefore the applicability to real-world scenarios. We propose a solution that achieves better generalization performance for the synchronization task compared to the available literature. The method is characterized by three stages: at first, deep convolutional neural network features are used to assess the visual similarity among the photos; then, pairs of similar photos are detected across different galleries and used to construct a graph; eventually, a probabilistic graphical model is used to estimate the temporal offset of each pair of galleries, by traversing the minimum spanning tree extracted from this graph. The experimental evaluation is conducted on four publicly available datasets covering different types of events, demonstrating the strength of our proposed method. A thorough discussion of the obtained results is provided for a critical assessment of the quality in synchronization.
no_new_dataset
0.945248
1610.09091
Shijia E
Shijia E, Yang Xiang, Mohan Zhang
Representation Learning Models for Entity Search
This paper has been withdrawn by the author because the proposed model need to be re-evaluate
null
null
null
cs.CL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We focus on the problem of learning distributed representations for entity search queries, named entities, and their short descriptions. With our representation learning models, the entity search query, named entity and description can be represented as low-dimensional vectors. Our goal is to develop a simple but effective model that can make the distributed representations of query related entities similar to the query in the vector space. Hence, we propose three kinds of learning strategies, and the difference between them mainly lies in how to deal with the relationship between an entity and its description. We analyze the strengths and weaknesses of each learning strategy and validate our methods on public datasets which contain four kinds of named entities, i.e., movies, TV shows, restaurants and celebrities. The experimental results indicate that our proposed methods can adapt to different types of entity search queries, and outperform the current state-of-the-art methods based on keyword matching and vanilla word2vec models. Besides, the proposed methods can be trained fast and be easily extended to other similar tasks.
[ { "version": "v1", "created": "Fri, 28 Oct 2016 06:33:33 GMT" }, { "version": "v2", "created": "Tue, 20 Dec 2016 02:19:01 GMT" }, { "version": "v3", "created": "Sun, 15 Jan 2017 13:57:23 GMT" } ]
2017-01-17T00:00:00
[ [ "E", "Shijia", "" ], [ "Xiang", "Yang", "" ], [ "Zhang", "Mohan", "" ] ]
TITLE: Representation Learning Models for Entity Search ABSTRACT: We focus on the problem of learning distributed representations for entity search queries, named entities, and their short descriptions. With our representation learning models, the entity search query, named entity and description can be represented as low-dimensional vectors. Our goal is to develop a simple but effective model that can make the distributed representations of query related entities similar to the query in the vector space. Hence, we propose three kinds of learning strategies, and the difference between them mainly lies in how to deal with the relationship between an entity and its description. We analyze the strengths and weaknesses of each learning strategy and validate our methods on public datasets which contain four kinds of named entities, i.e., movies, TV shows, restaurants and celebrities. The experimental results indicate that our proposed methods can adapt to different types of entity search queries, and outperform the current state-of-the-art methods based on keyword matching and vanilla word2vec models. Besides, the proposed methods can be trained fast and be easily extended to other similar tasks.
no_new_dataset
0.942718
1611.00463
Zahra Khatami
Zahra Khatami, Sungpack Hong, Jinsoo Lee, Siegfried Depner, Hassan Chafi, J. Ramanujam, and Hartmut Kaiser
A Load-Balanced Parallel and Distributed Sorting Algorithm Implemented with PGX.D
8 pages, 12 figures
null
null
null
cs.DC
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Sorting has been one of the most challenging studied problems in different scientific researches. Although many techniques and algorithms have been proposed on the theory of having efficient parallel sorting implementation, however achieving desired performance on different types of the architectures with large number of processors is still a challenging issue. Maximizing parallelism level in applications can be achieved by minimizing overheads due to load imbalance and waiting time due to memory latencies. In this paper, we present a distributed sorting algorithm implemented in PGX.D, a fast distributed graph processing system, which outperforms the Spark's distributed sorting implementation by around 2x-3x by hiding communication latencies and minimizing unnecessary overheads. Furthermore, it shows that the proposed PGX.D sorting method handles dataset containing many duplicated data entries efficiently and always results in keeping balanced workloads for different input data distribution types.
[ { "version": "v1", "created": "Wed, 2 Nov 2016 03:56:31 GMT" }, { "version": "v2", "created": "Sat, 14 Jan 2017 20:17:32 GMT" } ]
2017-01-17T00:00:00
[ [ "Khatami", "Zahra", "" ], [ "Hong", "Sungpack", "" ], [ "Lee", "Jinsoo", "" ], [ "Depner", "Siegfried", "" ], [ "Chafi", "Hassan", "" ], [ "Ramanujam", "J.", "" ], [ "Kaiser", "Hartmut", "" ] ]
TITLE: A Load-Balanced Parallel and Distributed Sorting Algorithm Implemented with PGX.D ABSTRACT: Sorting has been one of the most challenging studied problems in different scientific researches. Although many techniques and algorithms have been proposed on the theory of having efficient parallel sorting implementation, however achieving desired performance on different types of the architectures with large number of processors is still a challenging issue. Maximizing parallelism level in applications can be achieved by minimizing overheads due to load imbalance and waiting time due to memory latencies. In this paper, we present a distributed sorting algorithm implemented in PGX.D, a fast distributed graph processing system, which outperforms the Spark's distributed sorting implementation by around 2x-3x by hiding communication latencies and minimizing unnecessary overheads. Furthermore, it shows that the proposed PGX.D sorting method handles dataset containing many duplicated data entries efficiently and always results in keeping balanced workloads for different input data distribution types.
no_new_dataset
0.940188
1611.08069
Bo Li
Bo Li
3D Fully Convolutional Network for Vehicle Detection in Point Cloud
null
null
null
null
cs.CV cs.RO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
2D fully convolutional network has been recently successfully applied to object detection from images. In this paper, we extend the fully convolutional network based detection techniques to 3D and apply it to point cloud data. The proposed approach is verified on the task of vehicle detection from lidar point cloud for autonomous driving. Experiments on the KITTI dataset shows a significant performance improvement over the previous point cloud based detection approaches.
[ { "version": "v1", "created": "Thu, 24 Nov 2016 05:06:05 GMT" }, { "version": "v2", "created": "Mon, 16 Jan 2017 05:56:01 GMT" } ]
2017-01-17T00:00:00
[ [ "Li", "Bo", "" ] ]
TITLE: 3D Fully Convolutional Network for Vehicle Detection in Point Cloud ABSTRACT: 2D fully convolutional network has been recently successfully applied to object detection from images. In this paper, we extend the fully convolutional network based detection techniques to 3D and apply it to point cloud data. The proposed approach is verified on the task of vehicle detection from lidar point cloud for autonomous driving. Experiments on the KITTI dataset shows a significant performance improvement over the previous point cloud based detection approaches.
no_new_dataset
0.952397
1701.01500
Haiqiang Wang
Haiqiang Wang, Ioannis Katsavounidis, Jiantong Zhou, Jeonghoon Park, Shawmin Lei, Xin Zhou, Man-On Pun, Xin Jin, Ronggang Wang, Xu Wang, Yun Zhang, Jiwu Huang, Sam Kwong and C.-C. Jay Kuo
VideoSet: A Large-Scale Compressed Video Quality Dataset Based on JND Measurement
null
null
null
null
cs.MM
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A new methodology to measure coded image/video quality using the just-noticeable-difference (JND) idea was proposed. Several small JND-based image/video quality datasets were released by the Media Communications Lab at the University of Southern California. In this work, we present an effort to build a large-scale JND-based coded video quality dataset. The dataset consists of 220 5-second sequences in four resolutions (i.e., $1920 \times 1080$, $1280 \times 720$, $960 \times 540$ and $640 \times 360$). For each of the 880 video clips, we encode it using the H.264 codec with $QP=1, \cdots, 51$ and measure the first three JND points with 30+ subjects. The dataset is called the "VideoSet", which is an acronym for "Video Subject Evaluation Test (SET)". This work describes the subjective test procedure, detection and removal of outlying measured data, and the properties of collected JND data. Finally, the significance and implications of the VideoSet to future video coding research and standardization efforts are pointed out. All source/coded video clips as well as measured JND data included in the VideoSet are available to the public in the IEEE DataPort.
[ { "version": "v1", "created": "Thu, 5 Jan 2017 23:14:01 GMT" }, { "version": "v2", "created": "Sun, 15 Jan 2017 04:30:59 GMT" } ]
2017-01-17T00:00:00
[ [ "Wang", "Haiqiang", "" ], [ "Katsavounidis", "Ioannis", "" ], [ "Zhou", "Jiantong", "" ], [ "Park", "Jeonghoon", "" ], [ "Lei", "Shawmin", "" ], [ "Zhou", "Xin", "" ], [ "Pun", "Man-On", "" ], [ "Jin", "Xin", "" ], [ "Wang", "Ronggang", "" ], [ "Wang", "Xu", "" ], [ "Zhang", "Yun", "" ], [ "Huang", "Jiwu", "" ], [ "Kwong", "Sam", "" ], [ "Kuo", "C. -C. Jay", "" ] ]
TITLE: VideoSet: A Large-Scale Compressed Video Quality Dataset Based on JND Measurement ABSTRACT: A new methodology to measure coded image/video quality using the just-noticeable-difference (JND) idea was proposed. Several small JND-based image/video quality datasets were released by the Media Communications Lab at the University of Southern California. In this work, we present an effort to build a large-scale JND-based coded video quality dataset. The dataset consists of 220 5-second sequences in four resolutions (i.e., $1920 \times 1080$, $1280 \times 720$, $960 \times 540$ and $640 \times 360$). For each of the 880 video clips, we encode it using the H.264 codec with $QP=1, \cdots, 51$ and measure the first three JND points with 30+ subjects. The dataset is called the "VideoSet", which is an acronym for "Video Subject Evaluation Test (SET)". This work describes the subjective test procedure, detection and removal of outlying measured data, and the properties of collected JND data. Finally, the significance and implications of the VideoSet to future video coding research and standardization efforts are pointed out. All source/coded video clips as well as measured JND data included in the VideoSet are available to the public in the IEEE DataPort.
new_dataset
0.96395
1701.03162
Yifan Yang
Yifan Yang and Tian Qin and Yu-Heng Lei
Real-time eSports Match Result Prediction
8 pages, 8 figures
null
null
null
stat.AP cs.AI cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we try to predict the winning team of a match in the multiplayer eSports game Dota 2. To address the weaknesses of previous work, we consider more aspects of prior (pre-match) features from individual players' match history, as well as real-time (during-match) features at each minute as the match progresses. We use logistic regression, the proposed Attribute Sequence Model, and their combinations as the prediction models. In a dataset of 78362 matches where 20631 matches contain replay data, our experiments show that adding more aspects of prior features improves accuracy from 58.69% to 71.49%, and introducing real-time features achieves up to 93.73% accuracy when predicting at the 40th minute.
[ { "version": "v1", "created": "Sat, 10 Dec 2016 06:30:25 GMT" } ]
2017-01-17T00:00:00
[ [ "Yang", "Yifan", "" ], [ "Qin", "Tian", "" ], [ "Lei", "Yu-Heng", "" ] ]
TITLE: Real-time eSports Match Result Prediction ABSTRACT: In this paper, we try to predict the winning team of a match in the multiplayer eSports game Dota 2. To address the weaknesses of previous work, we consider more aspects of prior (pre-match) features from individual players' match history, as well as real-time (during-match) features at each minute as the match progresses. We use logistic regression, the proposed Attribute Sequence Model, and their combinations as the prediction models. In a dataset of 78362 matches where 20631 matches contain replay data, our experiments show that adding more aspects of prior features improves accuracy from 58.69% to 71.49%, and introducing real-time features achieves up to 93.73% accuracy when predicting at the 40th minute.
no_new_dataset
0.807916
1701.03869
Wenwen Ding
Wenwen Ding, Kai Liu
Learning Linear Dynamical Systems with High-Order Tensor Data for Skeleton based Action Recognition
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In recent years, there has been renewed interest in developing methods for skeleton-based human action recognition. A skeleton sequence can be naturally represented as a high-order tensor time series. In this paper, we model and analyze tensor time series with Linear Dynamical System (LDS) which is the most common for encoding spatio-temporal time-series data in various disciplines dut to its relative simplicity and efficiency. However, the traditional LDS treats the latent and observation state at each frame of video as a column vector. Such a vector representation fails to take into account the curse of dimensionality as well as valuable structural information with human action. Considering this fact, we propose generalized Linear Dynamical System (gLDS) for modeling tensor observation in the time series and employ Tucker decomposition to estimate the LDS parameters as action descriptors. Therefore, an action can be represented as a subspace corresponding to a point on a Grassmann manifold. Then we perform classification using dictionary learning and sparse coding over Grassmann manifold. Experiments on MSR Action3D Dataset, UCF Kinect Dataset and Northwestern-UCLA Multiview Action3D Dataset demonstrate that our proposed method achieves superior performance to the state-of-the-art algorithms.
[ { "version": "v1", "created": "Sat, 14 Jan 2017 02:07:23 GMT" } ]
2017-01-17T00:00:00
[ [ "Ding", "Wenwen", "" ], [ "Liu", "Kai", "" ] ]
TITLE: Learning Linear Dynamical Systems with High-Order Tensor Data for Skeleton based Action Recognition ABSTRACT: In recent years, there has been renewed interest in developing methods for skeleton-based human action recognition. A skeleton sequence can be naturally represented as a high-order tensor time series. In this paper, we model and analyze tensor time series with Linear Dynamical System (LDS) which is the most common for encoding spatio-temporal time-series data in various disciplines dut to its relative simplicity and efficiency. However, the traditional LDS treats the latent and observation state at each frame of video as a column vector. Such a vector representation fails to take into account the curse of dimensionality as well as valuable structural information with human action. Considering this fact, we propose generalized Linear Dynamical System (gLDS) for modeling tensor observation in the time series and employ Tucker decomposition to estimate the LDS parameters as action descriptors. Therefore, an action can be represented as a subspace corresponding to a point on a Grassmann manifold. Then we perform classification using dictionary learning and sparse coding over Grassmann manifold. Experiments on MSR Action3D Dataset, UCF Kinect Dataset and Northwestern-UCLA Multiview Action3D Dataset demonstrate that our proposed method achieves superior performance to the state-of-the-art algorithms.
no_new_dataset
0.950549
1701.03882
Natalia Antropova Natalia Antropova
Natalia Antropova, Benjamin Huynh, Maryellen Giger
Multi-task Learning in the Computerized Diagnosis of Breast Cancer on DCE-MRIs
null
null
null
null
physics.med-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Hand-crafted features extracted from dynamic contrast-enhanced magnetic resonance images (DCE-MRIs) have shown strong predictive abilities in characterization of breast lesions. However, heterogeneity across medical image datasets hinders the generalizability of these features. One of the sources of the heterogeneity is the variation of MR scanner magnet strength, which has a strong influence on image quality, leading to variations in the extracted image features. Thus, statistical decision algorithms need to account for such data heterogeneity. Despite the variations, we hypothesize that there exist underlying relationships between the features extracted from the datasets acquired with different magnet strength MR scanners. We compared the use of a multi-task learning (MTL) method that incorporates those relationships during the classifier training to support vector machines run on a merged dataset that includes cases with various MRI strength images. As a result, higher predictive power is achieved with the MTL method.
[ { "version": "v1", "created": "Sat, 14 Jan 2017 05:55:02 GMT" } ]
2017-01-17T00:00:00
[ [ "Antropova", "Natalia", "" ], [ "Huynh", "Benjamin", "" ], [ "Giger", "Maryellen", "" ] ]
TITLE: Multi-task Learning in the Computerized Diagnosis of Breast Cancer on DCE-MRIs ABSTRACT: Hand-crafted features extracted from dynamic contrast-enhanced magnetic resonance images (DCE-MRIs) have shown strong predictive abilities in characterization of breast lesions. However, heterogeneity across medical image datasets hinders the generalizability of these features. One of the sources of the heterogeneity is the variation of MR scanner magnet strength, which has a strong influence on image quality, leading to variations in the extracted image features. Thus, statistical decision algorithms need to account for such data heterogeneity. Despite the variations, we hypothesize that there exist underlying relationships between the features extracted from the datasets acquired with different magnet strength MR scanners. We compared the use of a multi-task learning (MTL) method that incorporates those relationships during the classifier training to support vector machines run on a merged dataset that includes cases with various MRI strength images. As a result, higher predictive power is achieved with the MTL method.
no_new_dataset
0.949201
1701.03937
Tuan Tran
Tuan Tran, Tu Ngoc Nguyen
Hedera: Scalable Indexing and Exploring Entities in Wikipedia Revision History
Pubished via CEUR-WS.org/Vol-1272
null
null
null
cs.AI cs.IR
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Much of work in semantic web relying on Wikipedia as the main source of knowledge often work on static snapshots of the dataset. The full history of Wikipedia revisions, while contains much more useful information, is still difficult to access due to its exceptional volume. To enable further research on this collection, we developed a tool, named Hedera, that efficiently extracts semantic information from Wikipedia revision history datasets. Hedera exploits Map-Reduce paradigm to achieve rapid extraction, it is able to handle one entire Wikipedia articles revision history within a day in a medium-scale cluster, and supports flexible data structures for various kinds of semantic web study.
[ { "version": "v1", "created": "Sat, 14 Jan 2017 15:47:06 GMT" } ]
2017-01-17T00:00:00
[ [ "Tran", "Tuan", "" ], [ "Nguyen", "Tu Ngoc", "" ] ]
TITLE: Hedera: Scalable Indexing and Exploring Entities in Wikipedia Revision History ABSTRACT: Much of work in semantic web relying on Wikipedia as the main source of knowledge often work on static snapshots of the dataset. The full history of Wikipedia revisions, while contains much more useful information, is still difficult to access due to its exceptional volume. To enable further research on this collection, we developed a tool, named Hedera, that efficiently extracts semantic information from Wikipedia revision history datasets. Hedera exploits Map-Reduce paradigm to achieve rapid extraction, it is able to handle one entire Wikipedia articles revision history within a day in a medium-scale cluster, and supports flexible data structures for various kinds of semantic web study.
no_new_dataset
0.943504