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1607.05140
Thanh-Toan Do
Thanh-Toan Do, Anh-Dzung Doan, Ngai-Man Cheung
Learning to Hash with Binary Deep Neural Network
Appearing in European Conference on Computer Vision (ECCV) 2016
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This work proposes deep network models and learning algorithms for unsupervised and supervised binary hashing. Our novel network design constrains one hidden layer to directly output the binary codes. This addresses a challenging issue in some previous works: optimizing non-smooth objective functions due to binarization. Moreover, we incorporate independence and balance properties in the direct and strict forms in the learning. Furthermore, we include similarity preserving property in our objective function. Our resulting optimization with these binary, independence, and balance constraints is difficult to solve. We propose to attack it with alternating optimization and careful relaxation. Experimental results on three benchmark datasets show that our proposed methods compare favorably with the state of the art.
[ { "version": "v1", "created": "Mon, 18 Jul 2016 15:48:58 GMT" } ]
2016-07-19T00:00:00
[ [ "Do", "Thanh-Toan", "" ], [ "Doan", "Anh-Dzung", "" ], [ "Cheung", "Ngai-Man", "" ] ]
TITLE: Learning to Hash with Binary Deep Neural Network ABSTRACT: This work proposes deep network models and learning algorithms for unsupervised and supervised binary hashing. Our novel network design constrains one hidden layer to directly output the binary codes. This addresses a challenging issue in some previous works: optimizing non-smooth objective functions due to binarization. Moreover, we incorporate independence and balance properties in the direct and strict forms in the learning. Furthermore, we include similarity preserving property in our objective function. Our resulting optimization with these binary, independence, and balance constraints is difficult to solve. We propose to attack it with alternating optimization and careful relaxation. Experimental results on three benchmark datasets show that our proposed methods compare favorably with the state of the art.
1607.05177
Aidean Sharghi
Aidean Sharghi, Boqing Gong, Mubarak Shah
Query-Focused Extractive Video Summarization
Accepted to ECCV 2016
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Video data is explosively growing. As a result of the "big video data", intelligent algorithms for automatic video summarization have re-emerged as a pressing need. We develop a probabilistic model, Sequential and Hierarchical Determinantal Point Process (SH-DPP), for query-focused extractive video summarization. Given a user query and a long video sequence, our algorithm returns a summary by selecting key shots from the video. The decision to include a shot in the summary depends on the shot's relevance to the user query and importance in the context of the video, jointly. We verify our approach on two densely annotated video datasets. The query-focused video summarization is particularly useful for search engines, e.g., to display snippets of videos.
[ { "version": "v1", "created": "Mon, 18 Jul 2016 16:49:19 GMT" } ]
2016-07-19T00:00:00
[ [ "Sharghi", "Aidean", "" ], [ "Gong", "Boqing", "" ], [ "Shah", "Mubarak", "" ] ]
TITLE: Query-Focused Extractive Video Summarization ABSTRACT: Video data is explosively growing. As a result of the "big video data", intelligent algorithms for automatic video summarization have re-emerged as a pressing need. We develop a probabilistic model, Sequential and Hierarchical Determinantal Point Process (SH-DPP), for query-focused extractive video summarization. Given a user query and a long video sequence, our algorithm returns a summary by selecting key shots from the video. The decision to include a shot in the summary depends on the shot's relevance to the user query and importance in the context of the video, jointly. We verify our approach on two densely annotated video datasets. The query-focused video summarization is particularly useful for search engines, e.g., to display snippets of videos.
1607.05194
Mohammad Havaei
Mohammad Havaei and Nicolas Guizard and Nicolas Chapados and Yoshua Bengio
HeMIS: Hetero-Modal Image Segmentation
Accepted as an oral presentation at MICCAI 2016
null
null
null
cs.CV
http://creativecommons.org/licenses/by-nc-sa/4.0/
We introduce a deep learning image segmentation framework that is extremely robust to missing imaging modalities. Instead of attempting to impute or synthesize missing data, the proposed approach learns, for each modality, an embedding of the input image into a single latent vector space for which arithmetic operations (such as taking the mean) are well defined. Points in that space, which are averaged over modalities available at inference time, can then be further processed to yield the desired segmentation. As such, any combinatorial subset of available modalities can be provided as input, without having to learn a combinatorial number of imputation models. Evaluated on two neurological MRI datasets (brain tumors and MS lesions), the approach yields state-of-the-art segmentation results when provided with all modalities; moreover, its performance degrades remarkably gracefully when modalities are removed, significantly more so than alternative mean-filling or other synthesis approaches.
[ { "version": "v1", "created": "Mon, 18 Jul 2016 17:11:57 GMT" } ]
2016-07-19T00:00:00
[ [ "Havaei", "Mohammad", "" ], [ "Guizard", "Nicolas", "" ], [ "Chapados", "Nicolas", "" ], [ "Bengio", "Yoshua", "" ] ]
TITLE: HeMIS: Hetero-Modal Image Segmentation ABSTRACT: We introduce a deep learning image segmentation framework that is extremely robust to missing imaging modalities. Instead of attempting to impute or synthesize missing data, the proposed approach learns, for each modality, an embedding of the input image into a single latent vector space for which arithmetic operations (such as taking the mean) are well defined. Points in that space, which are averaged over modalities available at inference time, can then be further processed to yield the desired segmentation. As such, any combinatorial subset of available modalities can be provided as input, without having to learn a combinatorial number of imputation models. Evaluated on two neurological MRI datasets (brain tumors and MS lesions), the approach yields state-of-the-art segmentation results when provided with all modalities; moreover, its performance degrades remarkably gracefully when modalities are removed, significantly more so than alternative mean-filling or other synthesis approaches.
1512.01818
Filipe Ribeiro Filipe Nunes Ribeiro
Filipe Nunes Ribeiro, Matheus Ara\'ujo, Pollyanna Gon\c{c}alves, Fabr\'icio Benevenuto, Marcos Andr\'e Gon\c{c}alves
SentiBench - a benchmark comparison of state-of-the-practice sentiment analysis methods
null
null
null
null
cs.CL cs.SI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the last few years thousands of scientific papers have investigated sentiment analysis, several startups that measure opinions on real data have emerged and a number of innovative products related to this theme have been developed. There are multiple methods for measuring sentiments, including lexical-based and supervised machine learning methods. Despite the vast interest on the theme and wide popularity of some methods, it is unclear which one is better for identifying the polarity (i.e., positive or negative) of a message. Accordingly, there is a strong need to conduct a thorough apple-to-apple comparison of sentiment analysis methods, \textit{as they are used in practice}, across multiple datasets originated from different data sources. Such a comparison is key for understanding the potential limitations, advantages, and disadvantages of popular methods. This article aims at filling this gap by presenting a benchmark comparison of twenty-four popular sentiment analysis methods (which we call the state-of-the-practice methods). Our evaluation is based on a benchmark of eighteen labeled datasets, covering messages posted on social networks, movie and product reviews, as well as opinions and comments in news articles. Our results highlight the extent to which the prediction performance of these methods varies considerably across datasets. Aiming at boosting the development of this research area, we open the methods' codes and datasets used in this article, deploying them in a benchmark system, which provides an open API for accessing and comparing sentence-level sentiment analysis methods.
[ { "version": "v1", "created": "Sun, 6 Dec 2015 18:52:51 GMT" }, { "version": "v2", "created": "Wed, 16 Dec 2015 00:32:23 GMT" }, { "version": "v3", "created": "Mon, 1 Feb 2016 18:54:51 GMT" }, { "version": "v4", "created": "Sat, 4 Jun 2016 16:52:29 GMT" }, { "version": "v5", "created": "Thu, 14 Jul 2016 22:51:39 GMT" } ]
2016-07-18T00:00:00
[ [ "Ribeiro", "Filipe Nunes", "" ], [ "Araújo", "Matheus", "" ], [ "Gonçalves", "Pollyanna", "" ], [ "Benevenuto", "Fabrício", "" ], [ "Gonçalves", "Marcos André", "" ] ]
TITLE: SentiBench - a benchmark comparison of state-of-the-practice sentiment analysis methods ABSTRACT: In the last few years thousands of scientific papers have investigated sentiment analysis, several startups that measure opinions on real data have emerged and a number of innovative products related to this theme have been developed. There are multiple methods for measuring sentiments, including lexical-based and supervised machine learning methods. Despite the vast interest on the theme and wide popularity of some methods, it is unclear which one is better for identifying the polarity (i.e., positive or negative) of a message. Accordingly, there is a strong need to conduct a thorough apple-to-apple comparison of sentiment analysis methods, \textit{as they are used in practice}, across multiple datasets originated from different data sources. Such a comparison is key for understanding the potential limitations, advantages, and disadvantages of popular methods. This article aims at filling this gap by presenting a benchmark comparison of twenty-four popular sentiment analysis methods (which we call the state-of-the-practice methods). Our evaluation is based on a benchmark of eighteen labeled datasets, covering messages posted on social networks, movie and product reviews, as well as opinions and comments in news articles. Our results highlight the extent to which the prediction performance of these methods varies considerably across datasets. Aiming at boosting the development of this research area, we open the methods' codes and datasets used in this article, deploying them in a benchmark system, which provides an open API for accessing and comparing sentence-level sentiment analysis methods.
1603.08120
Wenbin Li
Wenbin Li and Darren Cosker and Zhihan Lv and Matthew Brown
Nonrigid Optical Flow Ground Truth for Real-World Scenes with Time-Varying Shading Effects
preprint of our paper accepted by RA-L'16
null
10.1109/LRA.2016.2592513
null
cs.CV
http://creativecommons.org/licenses/by-nc-sa/4.0/
In this paper we present a dense ground truth dataset of nonrigidly deforming real-world scenes. Our dataset contains both long and short video sequences, and enables the quantitatively evaluation for RGB based tracking and registration methods. To construct ground truth for the RGB sequences, we simultaneously capture Near-Infrared (NIR) image sequences where dense markers - visible only in NIR - represent ground truth positions. This allows for comparison with automatically tracked RGB positions and the formation of error metrics. Most previous datasets containing nonrigidly deforming sequences are based on synthetic data. Our capture protocol enables us to acquire real-world deforming objects with realistic photometric effects - such as blur and illumination change - as well as occlusion and complex deformations. A public evaluation website is constructed to allow for ranking of RGB image based optical flow and other dense tracking algorithms, with various statistical measures. Furthermore, we present an RGB-NIR multispectral optical flow model allowing for energy optimization by adoptively combining featured information from both the RGB and the complementary NIR channels. In our experiments we evaluate eight existing RGB based optical flow methods on our new dataset. We also evaluate our hybrid optical flow algorithm by comparing to two existing multispectral approaches, as well as varying our input channels across RGB, NIR and RGB-NIR.
[ { "version": "v1", "created": "Sat, 26 Mar 2016 16:08:13 GMT" }, { "version": "v2", "created": "Sat, 25 Jun 2016 14:57:38 GMT" }, { "version": "v3", "created": "Fri, 15 Jul 2016 12:39:03 GMT" } ]
2016-07-18T00:00:00
[ [ "Li", "Wenbin", "" ], [ "Cosker", "Darren", "" ], [ "Lv", "Zhihan", "" ], [ "Brown", "Matthew", "" ] ]
TITLE: Nonrigid Optical Flow Ground Truth for Real-World Scenes with Time-Varying Shading Effects ABSTRACT: In this paper we present a dense ground truth dataset of nonrigidly deforming real-world scenes. Our dataset contains both long and short video sequences, and enables the quantitatively evaluation for RGB based tracking and registration methods. To construct ground truth for the RGB sequences, we simultaneously capture Near-Infrared (NIR) image sequences where dense markers - visible only in NIR - represent ground truth positions. This allows for comparison with automatically tracked RGB positions and the formation of error metrics. Most previous datasets containing nonrigidly deforming sequences are based on synthetic data. Our capture protocol enables us to acquire real-world deforming objects with realistic photometric effects - such as blur and illumination change - as well as occlusion and complex deformations. A public evaluation website is constructed to allow for ranking of RGB image based optical flow and other dense tracking algorithms, with various statistical measures. Furthermore, we present an RGB-NIR multispectral optical flow model allowing for energy optimization by adoptively combining featured information from both the RGB and the complementary NIR channels. In our experiments we evaluate eight existing RGB based optical flow methods on our new dataset. We also evaluate our hybrid optical flow algorithm by comparing to two existing multispectral approaches, as well as varying our input channels across RGB, NIR and RGB-NIR.
1607.04373
Ruining He
Ruining He, Chen Fang, Zhaowen Wang, Julian McAuley
Vista: A Visually, Socially, and Temporally-aware Model for Artistic Recommendation
8 pages, 3 figures
null
10.1145/2959100.2959152
null
cs.IR cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Understanding users' interactions with highly subjective content---like artistic images---is challenging due to the complex semantics that guide our preferences. On the one hand one has to overcome `standard' recommender systems challenges, such as dealing with large, sparse, and long-tailed datasets. On the other, several new challenges present themselves, such as the need to model content in terms of its visual appearance, or even social dynamics, such as a preference toward a particular artist that is independent of the art they create. In this paper we build large-scale recommender systems to model the dynamics of a vibrant digital art community, Behance, consisting of tens of millions of interactions (clicks and `appreciates') of users toward digital art. Methodologically, our main contributions are to model (a) rich content, especially in terms of its visual appearance; (b) temporal dynamics, in terms of how users prefer `visually consistent' content within and across sessions; and (c) social dynamics, in terms of how users exhibit preferences both towards certain art styles, as well as the artists themselves.
[ { "version": "v1", "created": "Fri, 15 Jul 2016 03:35:56 GMT" } ]
2016-07-18T00:00:00
[ [ "He", "Ruining", "" ], [ "Fang", "Chen", "" ], [ "Wang", "Zhaowen", "" ], [ "McAuley", "Julian", "" ] ]
TITLE: Vista: A Visually, Socially, and Temporally-aware Model for Artistic Recommendation ABSTRACT: Understanding users' interactions with highly subjective content---like artistic images---is challenging due to the complex semantics that guide our preferences. On the one hand one has to overcome `standard' recommender systems challenges, such as dealing with large, sparse, and long-tailed datasets. On the other, several new challenges present themselves, such as the need to model content in terms of its visual appearance, or even social dynamics, such as a preference toward a particular artist that is independent of the art they create. In this paper we build large-scale recommender systems to model the dynamics of a vibrant digital art community, Behance, consisting of tens of millions of interactions (clicks and `appreciates') of users toward digital art. Methodologically, our main contributions are to model (a) rich content, especially in terms of its visual appearance; (b) temporal dynamics, in terms of how users prefer `visually consistent' content within and across sessions; and (c) social dynamics, in terms of how users exhibit preferences both towards certain art styles, as well as the artists themselves.
1607.04378
Liping Jing Dr.
Liping Jing, Bo Liu, Jaeyoung Choi, Adam Janin, Julia Bernd, Michael W. Mahoney, and Gerald Friedland
DCAR: A Discriminative and Compact Audio Representation to Improve Event Detection
An abbreviated version of this paper will be published in ACM Multimedia 2016
null
null
null
cs.SD cs.MM
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper presents a novel two-phase method for audio representation, Discriminative and Compact Audio Representation (DCAR), and evaluates its performance at detecting events in consumer-produced videos. In the first phase of DCAR, each audio track is modeled using a Gaussian mixture model (GMM) that includes several components to capture the variability within that track. The second phase takes into account both global structure and local structure. In this phase, the components are rendered more discriminative and compact by formulating an optimization problem on Grassmannian manifolds, which we found represents the structure of audio effectively. Our experiments used the YLI-MED dataset (an open TRECVID-style video corpus based on YFCC100M), which includes ten events. The results show that the proposed DCAR representation consistently outperforms state-of-the-art audio representations. DCAR's advantage over i-vector, mv-vector, and GMM representations is significant for both easier and harder discrimination tasks. We discuss how these performance differences across easy and hard cases follow from how each type of model leverages (or doesn't leverage) the intrinsic structure of the data. Furthermore, DCAR shows a particularly notable accuracy advantage on events where humans have more difficulty classifying the videos, i.e., events with lower mean annotator confidence.
[ { "version": "v1", "created": "Fri, 15 Jul 2016 04:28:14 GMT" } ]
2016-07-18T00:00:00
[ [ "Jing", "Liping", "" ], [ "Liu", "Bo", "" ], [ "Choi", "Jaeyoung", "" ], [ "Janin", "Adam", "" ], [ "Bernd", "Julia", "" ], [ "Mahoney", "Michael W.", "" ], [ "Friedland", "Gerald", "" ] ]
TITLE: DCAR: A Discriminative and Compact Audio Representation to Improve Event Detection ABSTRACT: This paper presents a novel two-phase method for audio representation, Discriminative and Compact Audio Representation (DCAR), and evaluates its performance at detecting events in consumer-produced videos. In the first phase of DCAR, each audio track is modeled using a Gaussian mixture model (GMM) that includes several components to capture the variability within that track. The second phase takes into account both global structure and local structure. In this phase, the components are rendered more discriminative and compact by formulating an optimization problem on Grassmannian manifolds, which we found represents the structure of audio effectively. Our experiments used the YLI-MED dataset (an open TRECVID-style video corpus based on YFCC100M), which includes ten events. The results show that the proposed DCAR representation consistently outperforms state-of-the-art audio representations. DCAR's advantage over i-vector, mv-vector, and GMM representations is significant for both easier and harder discrimination tasks. We discuss how these performance differences across easy and hard cases follow from how each type of model leverages (or doesn't leverage) the intrinsic structure of the data. Furthermore, DCAR shows a particularly notable accuracy advantage on events where humans have more difficulty classifying the videos, i.e., events with lower mean annotator confidence.
1607.04379
Renzhi Cao
Renzhi Cao, Debswapna Bhattacharya, Jie Hou, and Jianlin Cheng
DeepQA: Improving the estimation of single protein model quality with deep belief networks
19 pages, 1 figure, 4 tables
null
null
null
cs.AI cs.LG q-bio.QM
http://creativecommons.org/licenses/by/4.0/
Protein quality assessment (QA) by ranking and selecting protein models has long been viewed as one of the major challenges for protein tertiary structure prediction. Especially, estimating the quality of a single protein model, which is important for selecting a few good models out of a large model pool consisting of mostly low-quality models, is still a largely unsolved problem. We introduce a novel single-model quality assessment method DeepQA based on deep belief network that utilizes a number of selected features describing the quality of a model from different perspectives, such as energy, physio-chemical characteristics, and structural information. The deep belief network is trained on several large datasets consisting of models from the Critical Assessment of Protein Structure Prediction (CASP) experiments, several publicly available datasets, and models generated by our in-house ab initio method. Our experiment demonstrate that deep belief network has better performance compared to Support Vector Machines and Neural Networks on the protein model quality assessment problem, and our method DeepQA achieves the state-of-the-art performance on CASP11 dataset. It also outperformed two well-established methods in selecting good outlier models from a large set of models of mostly low quality generated by ab initio modeling methods. DeepQA is a useful tool for protein single model quality assessment and protein structure prediction. The source code, executable, document and training/test datasets of DeepQA for Linux is freely available to non-commercial users at http://cactus.rnet.missouri.edu/DeepQA/.
[ { "version": "v1", "created": "Fri, 15 Jul 2016 04:28:55 GMT" } ]
2016-07-18T00:00:00
[ [ "Cao", "Renzhi", "" ], [ "Bhattacharya", "Debswapna", "" ], [ "Hou", "Jie", "" ], [ "Cheng", "Jianlin", "" ] ]
TITLE: DeepQA: Improving the estimation of single protein model quality with deep belief networks ABSTRACT: Protein quality assessment (QA) by ranking and selecting protein models has long been viewed as one of the major challenges for protein tertiary structure prediction. Especially, estimating the quality of a single protein model, which is important for selecting a few good models out of a large model pool consisting of mostly low-quality models, is still a largely unsolved problem. We introduce a novel single-model quality assessment method DeepQA based on deep belief network that utilizes a number of selected features describing the quality of a model from different perspectives, such as energy, physio-chemical characteristics, and structural information. The deep belief network is trained on several large datasets consisting of models from the Critical Assessment of Protein Structure Prediction (CASP) experiments, several publicly available datasets, and models generated by our in-house ab initio method. Our experiment demonstrate that deep belief network has better performance compared to Support Vector Machines and Neural Networks on the protein model quality assessment problem, and our method DeepQA achieves the state-of-the-art performance on CASP11 dataset. It also outperformed two well-established methods in selecting good outlier models from a large set of models of mostly low quality generated by ab initio modeling methods. DeepQA is a useful tool for protein single model quality assessment and protein structure prediction. The source code, executable, document and training/test datasets of DeepQA for Linux is freely available to non-commercial users at http://cactus.rnet.missouri.edu/DeepQA/.
1607.04593
Saurabh Prasad
Minshan Cui, Saurabh Prasad
Spatial Context based Angular Information Preserving Projection for Hyperspectral Image Classification
null
null
null
null
cs.CV
http://creativecommons.org/licenses/by/4.0/
Dimensionality reduction is a crucial preprocessing for hyperspectral data analysis - finding an appropriate subspace is often required for subsequent image classification. In recent work, we proposed supervised angular information based dimensionality reduction methods to find effective subspaces. Since unlabeled data are often more readily available compared to labeled data, we propose an unsupervised projection that finds a lower dimensional subspace where local angular information is preserved. To exploit spatial information from the hyperspectral images, we further extend our unsupervised projection to incorporate spatial contextual information around each pixel in the image. Additionally, we also propose a sparse representation based classifier which is optimized to exploit spatial information during classification - we hence assert that our proposed projection is particularly suitable for classifiers where local similarity and spatial context are both important. Experimental results with two real-world hyperspectral datasets demonstrate that our proposed methods provide a robust classification performance.
[ { "version": "v1", "created": "Fri, 15 Jul 2016 17:38:34 GMT" } ]
2016-07-18T00:00:00
[ [ "Cui", "Minshan", "" ], [ "Prasad", "Saurabh", "" ] ]
TITLE: Spatial Context based Angular Information Preserving Projection for Hyperspectral Image Classification ABSTRACT: Dimensionality reduction is a crucial preprocessing for hyperspectral data analysis - finding an appropriate subspace is often required for subsequent image classification. In recent work, we proposed supervised angular information based dimensionality reduction methods to find effective subspaces. Since unlabeled data are often more readily available compared to labeled data, we propose an unsupervised projection that finds a lower dimensional subspace where local angular information is preserved. To exploit spatial information from the hyperspectral images, we further extend our unsupervised projection to incorporate spatial contextual information around each pixel in the image. Additionally, we also propose a sparse representation based classifier which is optimized to exploit spatial information during classification - we hence assert that our proposed projection is particularly suitable for classifiers where local similarity and spatial context are both important. Experimental results with two real-world hyperspectral datasets demonstrate that our proposed methods provide a robust classification performance.
1412.7854
Seyedshams Feyzabadi
Seyedshams Feyzabadi
Joint Deep Learning for Car Detection
null
null
null
null
cs.CV
http://creativecommons.org/licenses/by/4.0/
Traditional object recognition approaches apply feature extraction, part deformation handling, occlusion handling and classification sequentially while they are independent from each other. Ouyang and Wang proposed a model for jointly learning of all of the mentioned processes using one deep neural network. We utilized, and manipulated their toolbox in order to apply it in car detection scenarios where it had not been tested. Creating a single deep architecture from these components, improves the interaction between them and can enhance the performance of the whole system. We believe that the approach can be used as a general purpose object detection toolbox. We tested the algorithm on UIUC car dataset, and achieved an outstanding result. The accuracy of our method was 97 % while the previously reported results showed an accuracy of up to 91 %. We strongly believe that having an experiment on a larger dataset can show the advantage of using deep models over shallow ones.
[ { "version": "v1", "created": "Thu, 25 Dec 2014 18:55:49 GMT" }, { "version": "v2", "created": "Thu, 14 Jul 2016 17:57:31 GMT" } ]
2016-07-15T00:00:00
[ [ "Feyzabadi", "Seyedshams", "" ] ]
TITLE: Joint Deep Learning for Car Detection ABSTRACT: Traditional object recognition approaches apply feature extraction, part deformation handling, occlusion handling and classification sequentially while they are independent from each other. Ouyang and Wang proposed a model for jointly learning of all of the mentioned processes using one deep neural network. We utilized, and manipulated their toolbox in order to apply it in car detection scenarios where it had not been tested. Creating a single deep architecture from these components, improves the interaction between them and can enhance the performance of the whole system. We believe that the approach can be used as a general purpose object detection toolbox. We tested the algorithm on UIUC car dataset, and achieved an outstanding result. The accuracy of our method was 97 % while the previously reported results showed an accuracy of up to 91 %. We strongly believe that having an experiment on a larger dataset can show the advantage of using deep models over shallow ones.
1604.05096
Jonas Uhrig
Jonas Uhrig, Marius Cordts, Uwe Franke, Thomas Brox
Pixel-level Encoding and Depth Layering for Instance-level Semantic Labeling
Accepted at GCPR 2016. Includes supplementary material
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recent approaches for instance-aware semantic labeling have augmented convolutional neural networks (CNNs) with complex multi-task architectures or computationally expensive graphical models. We present a method that leverages a fully convolutional network (FCN) to predict semantic labels, depth and an instance-based encoding using each pixel's direction towards its corresponding instance center. Subsequently, we apply low-level computer vision techniques to generate state-of-the-art instance segmentation on the street scene datasets KITTI and Cityscapes. Our approach outperforms existing works by a large margin and can additionally predict absolute distances of individual instances from a monocular image as well as a pixel-level semantic labeling.
[ { "version": "v1", "created": "Mon, 18 Apr 2016 11:24:39 GMT" }, { "version": "v2", "created": "Thu, 14 Jul 2016 14:46:35 GMT" } ]
2016-07-15T00:00:00
[ [ "Uhrig", "Jonas", "" ], [ "Cordts", "Marius", "" ], [ "Franke", "Uwe", "" ], [ "Brox", "Thomas", "" ] ]
TITLE: Pixel-level Encoding and Depth Layering for Instance-level Semantic Labeling ABSTRACT: Recent approaches for instance-aware semantic labeling have augmented convolutional neural networks (CNNs) with complex multi-task architectures or computationally expensive graphical models. We present a method that leverages a fully convolutional network (FCN) to predict semantic labels, depth and an instance-based encoding using each pixel's direction towards its corresponding instance center. Subsequently, we apply low-level computer vision techniques to generate state-of-the-art instance segmentation on the street scene datasets KITTI and Cityscapes. Our approach outperforms existing works by a large margin and can additionally predict absolute distances of individual instances from a monocular image as well as a pixel-level semantic labeling.
1606.08733
Ond\v{r}ej Pl\'atek
Ond\v{r}ej Pl\'atek and Petr B\v{e}lohl\'avek and Vojt\v{e}ch Hude\v{c}ek and Filip Jur\v{c}\'i\v{c}ek
Recurrent Neural Networks for Dialogue State Tracking
Accepted to slo-nlp 2016
null
null
null
cs.CL
http://creativecommons.org/licenses/by-sa/4.0/
This paper discusses models for dialogue state tracking using recurrent neural networks (RNN). We present experiments on the standard dialogue state tracking (DST) dataset, DSTC2. On the one hand, RNN models became the state of the art models in DST, on the other hand, most state-of-the-art models are only turn-based and require dataset-specific preprocessing (e.g. DSTC2-specific) in order to achieve such results. We implemented two architectures which can be used in incremental settings and require almost no preprocessing. We compare their performance to the benchmarks on DSTC2 and discuss their properties. With only trivial preprocessing, the performance of our models is close to the state-of- the-art results.
[ { "version": "v1", "created": "Tue, 28 Jun 2016 14:33:29 GMT" }, { "version": "v2", "created": "Wed, 13 Jul 2016 21:42:58 GMT" } ]
2016-07-15T00:00:00
[ [ "Plátek", "Ondřej", "" ], [ "Bělohlávek", "Petr", "" ], [ "Hudeček", "Vojtěch", "" ], [ "Jurčíček", "Filip", "" ] ]
TITLE: Recurrent Neural Networks for Dialogue State Tracking ABSTRACT: This paper discusses models for dialogue state tracking using recurrent neural networks (RNN). We present experiments on the standard dialogue state tracking (DST) dataset, DSTC2. On the one hand, RNN models became the state of the art models in DST, on the other hand, most state-of-the-art models are only turn-based and require dataset-specific preprocessing (e.g. DSTC2-specific) in order to achieve such results. We implemented two architectures which can be used in incremental settings and require almost no preprocessing. We compare their performance to the benchmarks on DSTC2 and discuss their properties. With only trivial preprocessing, the performance of our models is close to the state-of- the-art results.
1607.03990
Jerry Li
Jayadev Acharya, Ilias Diakonikolas, Jerry Li, Ludwig Schmidt
Fast Algorithms for Segmented Regression
27 pages, appeared in ICML 2016
null
null
null
cs.LG cs.DS math.ST stat.TH
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the fixed design segmented regression problem: Given noisy samples from a piecewise linear function $f$, we want to recover $f$ up to a desired accuracy in mean-squared error. Previous rigorous approaches for this problem rely on dynamic programming (DP) and, while sample efficient, have running time quadratic in the sample size. As our main contribution, we provide new sample near-linear time algorithms for the problem that -- while not being minimax optimal -- achieve a significantly better sample-time tradeoff on large datasets compared to the DP approach. Our experimental evaluation shows that, compared with the DP approach, our algorithms provide a convergence rate that is only off by a factor of $2$ to $4$, while achieving speedups of three orders of magnitude.
[ { "version": "v1", "created": "Thu, 14 Jul 2016 04:52:53 GMT" } ]
2016-07-15T00:00:00
[ [ "Acharya", "Jayadev", "" ], [ "Diakonikolas", "Ilias", "" ], [ "Li", "Jerry", "" ], [ "Schmidt", "Ludwig", "" ] ]
TITLE: Fast Algorithms for Segmented Regression ABSTRACT: We study the fixed design segmented regression problem: Given noisy samples from a piecewise linear function $f$, we want to recover $f$ up to a desired accuracy in mean-squared error. Previous rigorous approaches for this problem rely on dynamic programming (DP) and, while sample efficient, have running time quadratic in the sample size. As our main contribution, we provide new sample near-linear time algorithms for the problem that -- while not being minimax optimal -- achieve a significantly better sample-time tradeoff on large datasets compared to the DP approach. Our experimental evaluation shows that, compared with the DP approach, our algorithms provide a convergence rate that is only off by a factor of $2$ to $4$, while achieving speedups of three orders of magnitude.
1607.04186
Mathieu Acher
Mathieu Acher (DiverSe), Fran\c{c}ois Esnault (DiverSe)
Large-scale Analysis of Chess Games with Chess Engines: A Preliminary Report
null
null
null
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The strength of chess engines together with the availability of numerous chess games have attracted the attention of chess players, data scientists, and researchers during the last decades. State-of-the-art engines now provide an authoritative judgement that can be used in many applications like cheating detection, intrinsic ratings computation, skill assessment, or the study of human decision-making. A key issue for the research community is to gather a large dataset of chess games together with the judgement of chess engines. Unfortunately the analysis of each move takes lots of times. In this paper, we report our effort to analyse almost 5 millions chess games with a computing grid. During summer 2015, we processed 270 millions unique played positions using the Stockfish engine with a quite high depth (20). We populated a database of 1+ tera-octets of chess evaluations, representing an estimated time of 50 years of computation on a single machine. Our effort is a first step towards the replication of research results, the supply of open data and procedures for exploring new directions, and the investigation of software engineering/scalability issues when computing billions of moves.
[ { "version": "v1", "created": "Thu, 28 Apr 2016 08:37:43 GMT" } ]
2016-07-15T00:00:00
[ [ "Acher", "Mathieu", "", "DiverSe" ], [ "Esnault", "François", "", "DiverSe" ] ]
TITLE: Large-scale Analysis of Chess Games with Chess Engines: A Preliminary Report ABSTRACT: The strength of chess engines together with the availability of numerous chess games have attracted the attention of chess players, data scientists, and researchers during the last decades. State-of-the-art engines now provide an authoritative judgement that can be used in many applications like cheating detection, intrinsic ratings computation, skill assessment, or the study of human decision-making. A key issue for the research community is to gather a large dataset of chess games together with the judgement of chess engines. Unfortunately the analysis of each move takes lots of times. In this paper, we report our effort to analyse almost 5 millions chess games with a computing grid. During summer 2015, we processed 270 millions unique played positions using the Stockfish engine with a quite high depth (20). We populated a database of 1+ tera-octets of chess evaluations, representing an estimated time of 50 years of computation on a single machine. Our effort is a first step towards the replication of research results, the supply of open data and procedures for exploring new directions, and the investigation of software engineering/scalability issues when computing billions of moves.
1203.6276
Pekka Malo
Ankur Sinha, Pekka Malo, Timo Kuosmanen
A Multi-objective Exploratory Procedure for Regression Model Selection
in Journal of Computational and Graphical Statistics, Vol. 24, Iss. 1, 2015
null
10.1080/10618600.2014.899236
null
stat.CO cs.NE stat.AP
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Variable selection is recognized as one of the most critical steps in statistical modeling. The problems encountered in engineering and social sciences are commonly characterized by over-abundance of explanatory variables, non-linearities and unknown interdependencies between the regressors. An added difficulty is that the analysts may have little or no prior knowledge on the relative importance of the variables. To provide a robust method for model selection, this paper introduces the Multi-objective Genetic Algorithm for Variable Selection (MOGA-VS) that provides the user with an optimal set of regression models for a given data-set. The algorithm considers the regression problem as a two objective task, and explores the Pareto-optimal (best subset) models by preferring those models over the other which have less number of regression coefficients and better goodness of fit. The model exploration can be performed based on in-sample or generalization error minimization. The model selection is proposed to be performed in two steps. First, we generate the frontier of Pareto-optimal regression models by eliminating the dominated models without any user intervention. Second, a decision making process is executed which allows the user to choose the most preferred model using visualisations and simple metrics. The method has been evaluated on a recently published real dataset on Communities and Crime within United States.
[ { "version": "v1", "created": "Wed, 28 Mar 2012 14:15:24 GMT" }, { "version": "v2", "created": "Fri, 28 Sep 2012 15:54:33 GMT" }, { "version": "v3", "created": "Tue, 23 Jul 2013 22:34:01 GMT" }, { "version": "v4", "created": "Wed, 13 Jul 2016 07:53:01 GMT" } ]
2016-07-14T00:00:00
[ [ "Sinha", "Ankur", "" ], [ "Malo", "Pekka", "" ], [ "Kuosmanen", "Timo", "" ] ]
TITLE: A Multi-objective Exploratory Procedure for Regression Model Selection ABSTRACT: Variable selection is recognized as one of the most critical steps in statistical modeling. The problems encountered in engineering and social sciences are commonly characterized by over-abundance of explanatory variables, non-linearities and unknown interdependencies between the regressors. An added difficulty is that the analysts may have little or no prior knowledge on the relative importance of the variables. To provide a robust method for model selection, this paper introduces the Multi-objective Genetic Algorithm for Variable Selection (MOGA-VS) that provides the user with an optimal set of regression models for a given data-set. The algorithm considers the regression problem as a two objective task, and explores the Pareto-optimal (best subset) models by preferring those models over the other which have less number of regression coefficients and better goodness of fit. The model exploration can be performed based on in-sample or generalization error minimization. The model selection is proposed to be performed in two steps. First, we generate the frontier of Pareto-optimal regression models by eliminating the dominated models without any user intervention. Second, a decision making process is executed which allows the user to choose the most preferred model using visualisations and simple metrics. The method has been evaluated on a recently published real dataset on Communities and Crime within United States.
1604.05472
Arpita Biswas
Ragavendran Gopalakrishnan, Arpita Biswas, Alefiya Lightwala, Skanda Vasudevan, Partha Dutta, Abhishek Tripathi
Demand Prediction and Placement Optimization for Electric Vehicle Charging Stations
Published in the proceedings of the 25th International Joint Conference on Artificial Intelligence IJCAI 2016
null
null
null
cs.AI cs.DS
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Effective placement of charging stations plays a key role in Electric Vehicle (EV) adoption. In the placement problem, given a set of candidate sites, an optimal subset needs to be selected with respect to the concerns of both (a) the charging station service provider, such as the demand at the candidate sites and the budget for deployment, and (b) the EV user, such as charging station reachability and short waiting times at the station. This work addresses these concerns, making the following three novel contributions: (i) a supervised multi-view learning framework using Canonical Correlation Analysis (CCA) for demand prediction at candidate sites, using multiple datasets such as points of interest information, traffic density, and the historical usage at existing charging stations; (ii) a mixed-packing-and- covering optimization framework that models competing concerns of the service provider and EV users; (iii) an iterative heuristic to solve these problems by alternately invoking knapsack and set cover algorithms. The performance of the demand prediction model and the placement optimization heuristic are evaluated using real world data.
[ { "version": "v1", "created": "Tue, 19 Apr 2016 08:51:03 GMT" }, { "version": "v2", "created": "Wed, 13 Jul 2016 14:30:23 GMT" } ]
2016-07-14T00:00:00
[ [ "Gopalakrishnan", "Ragavendran", "" ], [ "Biswas", "Arpita", "" ], [ "Lightwala", "Alefiya", "" ], [ "Vasudevan", "Skanda", "" ], [ "Dutta", "Partha", "" ], [ "Tripathi", "Abhishek", "" ] ]
TITLE: Demand Prediction and Placement Optimization for Electric Vehicle Charging Stations ABSTRACT: Effective placement of charging stations plays a key role in Electric Vehicle (EV) adoption. In the placement problem, given a set of candidate sites, an optimal subset needs to be selected with respect to the concerns of both (a) the charging station service provider, such as the demand at the candidate sites and the budget for deployment, and (b) the EV user, such as charging station reachability and short waiting times at the station. This work addresses these concerns, making the following three novel contributions: (i) a supervised multi-view learning framework using Canonical Correlation Analysis (CCA) for demand prediction at candidate sites, using multiple datasets such as points of interest information, traffic density, and the historical usage at existing charging stations; (ii) a mixed-packing-and- covering optimization framework that models competing concerns of the service provider and EV users; (iii) an iterative heuristic to solve these problems by alternately invoking knapsack and set cover algorithms. The performance of the demand prediction model and the placement optimization heuristic are evaluated using real world data.
1607.03691
Gabriella Contardo
Gabriella Contardo, Ludovic Denoyer, Thierry Arti\`eres
Sequential Cost-Sensitive Feature Acquisition
12 pages, conference : accepted at IDA 2016
null
null
null
cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a reinforcement learning based approach to tackle the cost-sensitive learning problem where each input feature has a specific cost. The acquisition process is handled through a stochastic policy which allows features to be acquired in an adaptive way. The general architecture of our approach relies on representation learning to enable performing prediction on any partially observed sample, whatever the set of its observed features are. The resulting model is an original mix of representation learning and of reinforcement learning ideas. It is learned with policy gradient techniques to minimize a budgeted inference cost. We demonstrate the effectiveness of our proposed method with several experiments on a variety of datasets for the sparse prediction problem where all features have the same cost, but also for some cost-sensitive settings.
[ { "version": "v1", "created": "Wed, 13 Jul 2016 12:10:08 GMT" } ]
2016-07-14T00:00:00
[ [ "Contardo", "Gabriella", "" ], [ "Denoyer", "Ludovic", "" ], [ "Artières", "Thierry", "" ] ]
TITLE: Sequential Cost-Sensitive Feature Acquisition ABSTRACT: We propose a reinforcement learning based approach to tackle the cost-sensitive learning problem where each input feature has a specific cost. The acquisition process is handled through a stochastic policy which allows features to be acquired in an adaptive way. The general architecture of our approach relies on representation learning to enable performing prediction on any partially observed sample, whatever the set of its observed features are. The resulting model is an original mix of representation learning and of reinforcement learning ideas. It is learned with policy gradient techniques to minimize a budgeted inference cost. We demonstrate the effectiveness of our proposed method with several experiments on a variety of datasets for the sparse prediction problem where all features have the same cost, but also for some cost-sensitive settings.
1607.03705
Philippe Leray
Maroua Haddad (LINA, LARODEC), Philippe Leray (LINA), Nahla Ben Amor (LARODEC)
Possibilistic Networks: Parameters Learning from Imprecise Data and Evaluation strategy
null
null
null
null
cs.AI cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
There has been an ever-increasing interest in multidisciplinary research on representing and reasoning with imperfect data. Possibilistic networks present one of the powerful frameworks of interest for representing uncertain and imprecise information. This paper covers the problem of their parameters learning from imprecise datasets, i.e., containing multi-valued data. We propose in the rst part of this paper a possibilistic networks sampling process. In the second part, we propose a likelihood function which explores the link between random sets theory and possibility theory. This function is then deployed to parametrize possibilistic networks.
[ { "version": "v1", "created": "Wed, 13 Jul 2016 12:45:53 GMT" } ]
2016-07-14T00:00:00
[ [ "Haddad", "Maroua", "", "LINA, LARODEC" ], [ "Leray", "Philippe", "", "LINA" ], [ "Amor", "Nahla Ben", "", "LARODEC" ] ]
TITLE: Possibilistic Networks: Parameters Learning from Imprecise Data and Evaluation strategy ABSTRACT: There has been an ever-increasing interest in multidisciplinary research on representing and reasoning with imperfect data. Possibilistic networks present one of the powerful frameworks of interest for representing uncertain and imprecise information. This paper covers the problem of their parameters learning from imprecise datasets, i.e., containing multi-valued data. We propose in the rst part of this paper a possibilistic networks sampling process. In the second part, we propose a likelihood function which explores the link between random sets theory and possibility theory. This function is then deployed to parametrize possibilistic networks.
1603.01431
Devansh Arpit
Devansh Arpit, Yingbo Zhou, Bhargava U. Kota, Venu Govindaraju
Normalization Propagation: A Parametric Technique for Removing Internal Covariate Shift in Deep Networks
11 pages, ICML 2016, appendix added to the last version
null
null
null
stat.ML cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
While the authors of Batch Normalization (BN) identify and address an important problem involved in training deep networks-- Internal Covariate Shift-- the current solution has certain drawbacks. Specifically, BN depends on batch statistics for layerwise input normalization during training which makes the estimates of mean and standard deviation of input (distribution) to hidden layers inaccurate for validation due to shifting parameter values (especially during initial training epochs). Also, BN cannot be used with batch-size 1 during training. We address these drawbacks by proposing a non-adaptive normalization technique for removing internal covariate shift, that we call Normalization Propagation. Our approach does not depend on batch statistics, but rather uses a data-independent parametric estimate of mean and standard-deviation in every layer thus being computationally faster compared with BN. We exploit the observation that the pre-activation before Rectified Linear Units follow Gaussian distribution in deep networks, and that once the first and second order statistics of any given dataset are normalized, we can forward propagate this normalization without the need for recalculating the approximate statistics for hidden layers.
[ { "version": "v1", "created": "Fri, 4 Mar 2016 12:01:58 GMT" }, { "version": "v2", "created": "Wed, 9 Mar 2016 16:41:25 GMT" }, { "version": "v3", "created": "Mon, 23 May 2016 23:01:55 GMT" }, { "version": "v4", "created": "Mon, 30 May 2016 02:08:06 GMT" }, { "version": "v5", "created": "Sun, 3 Jul 2016 20:17:44 GMT" }, { "version": "v6", "created": "Tue, 12 Jul 2016 13:57:19 GMT" } ]
2016-07-13T00:00:00
[ [ "Arpit", "Devansh", "" ], [ "Zhou", "Yingbo", "" ], [ "Kota", "Bhargava U.", "" ], [ "Govindaraju", "Venu", "" ] ]
TITLE: Normalization Propagation: A Parametric Technique for Removing Internal Covariate Shift in Deep Networks ABSTRACT: While the authors of Batch Normalization (BN) identify and address an important problem involved in training deep networks-- Internal Covariate Shift-- the current solution has certain drawbacks. Specifically, BN depends on batch statistics for layerwise input normalization during training which makes the estimates of mean and standard deviation of input (distribution) to hidden layers inaccurate for validation due to shifting parameter values (especially during initial training epochs). Also, BN cannot be used with batch-size 1 during training. We address these drawbacks by proposing a non-adaptive normalization technique for removing internal covariate shift, that we call Normalization Propagation. Our approach does not depend on batch statistics, but rather uses a data-independent parametric estimate of mean and standard-deviation in every layer thus being computationally faster compared with BN. We exploit the observation that the pre-activation before Rectified Linear Units follow Gaussian distribution in deep networks, and that once the first and second order statistics of any given dataset are normalized, we can forward propagate this normalization without the need for recalculating the approximate statistics for hidden layers.
1603.05587
Mohammad Ghasemi Hamed
Mohammad Ghasemi Hamed and Masoud Ebadi Kivaj
Reliable Prediction Intervals for Local Linear Regression
40 pages,11 figures, 10 tables and 1 algorithm. arXiv admin note: text overlap with arXiv:1402.5874
null
null
null
stat.ME cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper introduces two methods for estimating reliable prediction intervals for local linear least-squares regressions, named Bounded Oscillation Prediction Intervals (BOPI). It also proposes a new measure for comparing interval prediction models named Equivalent Gaussian Standard Deviation (EGSD). The experimental results compare BOPI to other methods using coverage probability, Mean Interval Size and the introduced EGSD measure. The results were generally in favor of the BOPI on considered benchmark regression datasets. It also, reports simulation studies validating the BOPI method's reliability.
[ { "version": "v1", "created": "Thu, 17 Mar 2016 17:39:12 GMT" }, { "version": "v2", "created": "Fri, 18 Mar 2016 17:54:37 GMT" }, { "version": "v3", "created": "Wed, 30 Mar 2016 21:52:48 GMT" }, { "version": "v4", "created": "Fri, 1 Apr 2016 10:23:38 GMT" }, { "version": "v5", "created": "Tue, 12 Jul 2016 17:39:50 GMT" } ]
2016-07-13T00:00:00
[ [ "Hamed", "Mohammad Ghasemi", "" ], [ "Kivaj", "Masoud Ebadi", "" ] ]
TITLE: Reliable Prediction Intervals for Local Linear Regression ABSTRACT: This paper introduces two methods for estimating reliable prediction intervals for local linear least-squares regressions, named Bounded Oscillation Prediction Intervals (BOPI). It also proposes a new measure for comparing interval prediction models named Equivalent Gaussian Standard Deviation (EGSD). The experimental results compare BOPI to other methods using coverage probability, Mean Interval Size and the introduced EGSD measure. The results were generally in favor of the BOPI on considered benchmark regression datasets. It also, reports simulation studies validating the BOPI method's reliability.
1604.07939
Andre Araujo
Andre Araujo, Jason Chaves, Haricharan Lakshman, Roland Angst, Bernd Girod
Large-Scale Query-by-Image Video Retrieval Using Bloom Filters
null
null
null
null
cs.MM cs.DB cs.IR
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the problem of using image queries to retrieve videos from a database. Our focus is on large-scale applications, where it is infeasible to index each database video frame independently. Our main contribution is a framework based on Bloom filters, which can be used to index long video segments, enabling efficient image-to-video comparisons. Using this framework, we investigate several retrieval architectures, by considering different types of aggregation and different functions to encode visual information -- these play a crucial role in achieving high performance. Extensive experiments show that the proposed technique improves mean average precision by 24% on a public dataset, while being 4X faster, compared to the previous state-of-the-art.
[ { "version": "v1", "created": "Wed, 27 Apr 2016 05:46:52 GMT" }, { "version": "v2", "created": "Tue, 12 Jul 2016 17:58:16 GMT" } ]
2016-07-13T00:00:00
[ [ "Araujo", "Andre", "" ], [ "Chaves", "Jason", "" ], [ "Lakshman", "Haricharan", "" ], [ "Angst", "Roland", "" ], [ "Girod", "Bernd", "" ] ]
TITLE: Large-Scale Query-by-Image Video Retrieval Using Bloom Filters ABSTRACT: We consider the problem of using image queries to retrieve videos from a database. Our focus is on large-scale applications, where it is infeasible to index each database video frame independently. Our main contribution is a framework based on Bloom filters, which can be used to index long video segments, enabling efficient image-to-video comparisons. Using this framework, we investigate several retrieval architectures, by considering different types of aggregation and different functions to encode visual information -- these play a crucial role in achieving high performance. Extensive experiments show that the proposed technique improves mean average precision by 24% on a public dataset, while being 4X faster, compared to the previous state-of-the-art.
1607.03226
Xiaoyue Jiang
Xiaoyue Jiang, Dong Zhang and Xiaoyi Feng
Local feature hierarchy for face recognition across pose and illumination
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Even though face recognition in frontal view and normal lighting condition works very well, the performance degenerates sharply in extreme conditions. Recently there are many work dealing with pose and illumination problems, respectively. However both the lighting and pose variation will always be encountered at the same time. Accordingly we propose an end-to-end face recognition method to deal with pose and illumination simultaneously based on convolutional networks where the discriminative nonlinear features that are invariant to pose and illumination are extracted. Normally the global structure for images taken in different views is quite diverse. Therefore we propose to use the 1*1 convolutional kernel to extract the local features. Furthermore the parallel multi-stream multi-layer 1*1 convolution network is developed to extract multi-hierarchy features. In the experiments we obtained the average face recognition rate of 96.9% on multiPIE dataset,which improves the state-of-the-art of face recognition across poses and illumination by 7.5%. Especially for profile-wise positions, the average recognition rate of our proposed network is 97.8%, which increases the state-of-the-art recognition rate by 19%.
[ { "version": "v1", "created": "Tue, 12 Jul 2016 03:52:30 GMT" } ]
2016-07-13T00:00:00
[ [ "Jiang", "Xiaoyue", "" ], [ "Zhang", "Dong", "" ], [ "Feng", "Xiaoyi", "" ] ]
TITLE: Local feature hierarchy for face recognition across pose and illumination ABSTRACT: Even though face recognition in frontal view and normal lighting condition works very well, the performance degenerates sharply in extreme conditions. Recently there are many work dealing with pose and illumination problems, respectively. However both the lighting and pose variation will always be encountered at the same time. Accordingly we propose an end-to-end face recognition method to deal with pose and illumination simultaneously based on convolutional networks where the discriminative nonlinear features that are invariant to pose and illumination are extracted. Normally the global structure for images taken in different views is quite diverse. Therefore we propose to use the 1*1 convolutional kernel to extract the local features. Furthermore the parallel multi-stream multi-layer 1*1 convolution network is developed to extract multi-hierarchy features. In the experiments we obtained the average face recognition rate of 96.9% on multiPIE dataset,which improves the state-of-the-art of face recognition across poses and illumination by 7.5%. Especially for profile-wise positions, the average recognition rate of our proposed network is 97.8%, which increases the state-of-the-art recognition rate by 19%.
1607.03240
Sohil Shah
Sohil Shah, Kuldeep Kulkarni, Arijit Biswas, Ankit Gandhi, Om Deshmukh and Larry Davis
Weakly Supervised Learning of Heterogeneous Concepts in Videos
To appear at ECCV 2016
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Typical textual descriptions that accompany online videos are 'weak': i.e., they mention the main concepts in the video but not their corresponding spatio-temporal locations. The concepts in the description are typically heterogeneous (e.g., objects, persons, actions). Certain location constraints on these concepts can also be inferred from the description. The goal of this paper is to present a generalization of the Indian Buffet Process (IBP) that can (a) systematically incorporate heterogeneous concepts in an integrated framework, and (b) enforce location constraints, for efficient classification and localization of the concepts in the videos. Finally, we develop posterior inference for the proposed formulation using mean-field variational approximation. Comparative evaluations on the Casablanca and the A2D datasets show that the proposed approach significantly outperforms other state-of-the-art techniques: 24% relative improvement for pairwise concept classification in the Casablanca dataset and 9% relative improvement for localization in the A2D dataset as compared to the most competitive baseline.
[ { "version": "v1", "created": "Tue, 12 Jul 2016 06:49:49 GMT" } ]
2016-07-13T00:00:00
[ [ "Shah", "Sohil", "" ], [ "Kulkarni", "Kuldeep", "" ], [ "Biswas", "Arijit", "" ], [ "Gandhi", "Ankit", "" ], [ "Deshmukh", "Om", "" ], [ "Davis", "Larry", "" ] ]
TITLE: Weakly Supervised Learning of Heterogeneous Concepts in Videos ABSTRACT: Typical textual descriptions that accompany online videos are 'weak': i.e., they mention the main concepts in the video but not their corresponding spatio-temporal locations. The concepts in the description are typically heterogeneous (e.g., objects, persons, actions). Certain location constraints on these concepts can also be inferred from the description. The goal of this paper is to present a generalization of the Indian Buffet Process (IBP) that can (a) systematically incorporate heterogeneous concepts in an integrated framework, and (b) enforce location constraints, for efficient classification and localization of the concepts in the videos. Finally, we develop posterior inference for the proposed formulation using mean-field variational approximation. Comparative evaluations on the Casablanca and the A2D datasets show that the proposed approach significantly outperforms other state-of-the-art techniques: 24% relative improvement for pairwise concept classification in the Casablanca dataset and 9% relative improvement for localization in the A2D dataset as compared to the most competitive baseline.
1607.03250
Hengyuan Hu
Hengyuan Hu, Rui Peng, Yu-Wing Tai, Chi-Keung Tang
Network Trimming: A Data-Driven Neuron Pruning Approach towards Efficient Deep Architectures
null
null
null
null
cs.NE cs.CV cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
State-of-the-art neural networks are getting deeper and wider. While their performance increases with the increasing number of layers and neurons, it is crucial to design an efficient deep architecture in order to reduce computational and memory costs. Designing an efficient neural network, however, is labor intensive requiring many experiments, and fine-tunings. In this paper, we introduce network trimming which iteratively optimizes the network by pruning unimportant neurons based on analysis of their outputs on a large dataset. Our algorithm is inspired by an observation that the outputs of a significant portion of neurons in a large network are mostly zero, regardless of what inputs the network received. These zero activation neurons are redundant, and can be removed without affecting the overall accuracy of the network. After pruning the zero activation neurons, we retrain the network using the weights before pruning as initialization. We alternate the pruning and retraining to further reduce zero activations in a network. Our experiments on the LeNet and VGG-16 show that we can achieve high compression ratio of parameters without losing or even achieving higher accuracy than the original network.
[ { "version": "v1", "created": "Tue, 12 Jul 2016 07:43:01 GMT" } ]
2016-07-13T00:00:00
[ [ "Hu", "Hengyuan", "" ], [ "Peng", "Rui", "" ], [ "Tai", "Yu-Wing", "" ], [ "Tang", "Chi-Keung", "" ] ]
TITLE: Network Trimming: A Data-Driven Neuron Pruning Approach towards Efficient Deep Architectures ABSTRACT: State-of-the-art neural networks are getting deeper and wider. While their performance increases with the increasing number of layers and neurons, it is crucial to design an efficient deep architecture in order to reduce computational and memory costs. Designing an efficient neural network, however, is labor intensive requiring many experiments, and fine-tunings. In this paper, we introduce network trimming which iteratively optimizes the network by pruning unimportant neurons based on analysis of their outputs on a large dataset. Our algorithm is inspired by an observation that the outputs of a significant portion of neurons in a large network are mostly zero, regardless of what inputs the network received. These zero activation neurons are redundant, and can be removed without affecting the overall accuracy of the network. After pruning the zero activation neurons, we retrain the network using the weights before pruning as initialization. We alternate the pruning and retraining to further reduce zero activations in a network. Our experiments on the LeNet and VGG-16 show that we can achieve high compression ratio of parameters without losing or even achieving higher accuracy than the original network.
1607.03274
Maria Han Veiga
Maria Han Veiga and Carsten Eickhoff
A Cross-Platform Collection of Social Network Profiles
4 pages, 5 figures, SIGIR 2016, short paper. SIGIR 2016 Proceedings of the 39th International ACM SIGIR conference on Research and Development in Information Retrieval
null
10.1145/2911451.2914666
null
cs.IR cs.SI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The proliferation of Internet-enabled devices and services has led to a shifting balance between digital and analogue aspects of our everyday lives. In the face of this development there is a growing demand for the study of privacy hazards, the potential for unique user de-anonymization and information leakage between the various social media profiles many of us maintain. To enable the structured study of such adversarial effects, this paper presents a dedicated dataset of cross-platform social network personas (i.e., the same person has accounts on multiple platforms). The corpus comprises 850 users who generate predominantly English content. Each user object contains the online footprint of the same person in three distinct social networks: Twitter, Instagram and Foursquare. In total, it encompasses over 2.5M tweets, 340k check-ins and 42k Instagram posts. We describe the collection methodology, characteristics of the dataset, and how to obtain it. Finally, we discuss a common use case, cross-platform user identification.
[ { "version": "v1", "created": "Tue, 12 Jul 2016 09:09:58 GMT" } ]
2016-07-13T00:00:00
[ [ "Veiga", "Maria Han", "" ], [ "Eickhoff", "Carsten", "" ] ]
TITLE: A Cross-Platform Collection of Social Network Profiles ABSTRACT: The proliferation of Internet-enabled devices and services has led to a shifting balance between digital and analogue aspects of our everyday lives. In the face of this development there is a growing demand for the study of privacy hazards, the potential for unique user de-anonymization and information leakage between the various social media profiles many of us maintain. To enable the structured study of such adversarial effects, this paper presents a dedicated dataset of cross-platform social network personas (i.e., the same person has accounts on multiple platforms). The corpus comprises 850 users who generate predominantly English content. Each user object contains the online footprint of the same person in three distinct social networks: Twitter, Instagram and Foursquare. In total, it encompasses over 2.5M tweets, 340k check-ins and 42k Instagram posts. We describe the collection methodology, characteristics of the dataset, and how to obtain it. Finally, we discuss a common use case, cross-platform user identification.
1607.03305
Martin Cadik
Martin Cadik and Jan Vasicek and Michal Hradis and Filip Radenovic and Ondrej Chum
Camera Elevation Estimation from a Single Mountain Landscape Photograph
null
In Xianghua Xie, Mark W. Jones, and Gary K. L. Tam, editors, Proceedings of the British Machine Vision Conference (BMVC), pages 30.1-30.12. BMVA Press, September 2015
10.5244/C.29.30
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This work addresses the problem of camera elevation estimation from a single photograph in an outdoor environment. We introduce a new benchmark dataset of one-hundred thousand images with annotated camera elevation called Alps100K. We propose and experimentally evaluate two automatic data-driven approaches to camera elevation estimation: one based on convolutional neural networks, the other on local features. To compare the proposed methods to human performance, an experiment with 100 subjects is conducted. The experimental results show that both proposed approaches outperform humans and that the best result is achieved by their combination.
[ { "version": "v1", "created": "Tue, 12 Jul 2016 10:47:51 GMT" } ]
2016-07-13T00:00:00
[ [ "Cadik", "Martin", "" ], [ "Vasicek", "Jan", "" ], [ "Hradis", "Michal", "" ], [ "Radenovic", "Filip", "" ], [ "Chum", "Ondrej", "" ] ]
TITLE: Camera Elevation Estimation from a Single Mountain Landscape Photograph ABSTRACT: This work addresses the problem of camera elevation estimation from a single photograph in an outdoor environment. We introduce a new benchmark dataset of one-hundred thousand images with annotated camera elevation called Alps100K. We propose and experimentally evaluate two automatic data-driven approaches to camera elevation estimation: one based on convolutional neural networks, the other on local features. To compare the proposed methods to human performance, an experiment with 100 subjects is conducted. The experimental results show that both proposed approaches outperform humans and that the best result is achieved by their combination.
1607.03380
Yangqing Li
Yangqing Li and Saurabh Prasad and Wei Chen and Changchuan Yin and Zhu Han
An approximate message passing approach for compressive hyperspectral imaging using a simultaneous low-rank and joint-sparsity prior
null
null
null
null
cs.IT math.IT
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper considers a compressive sensing (CS) approach for hyperspectral data acquisition, which results in a practical compression ratio substantially higher than the state-of-the-art. Applying simultaneous low-rank and joint-sparse (L&S) model to the hyperspectral data, we propose a novel algorithm to joint reconstruction of hyperspectral data based on loopy belief propagation that enables the exploitation of both structured sparsity and amplitude correlations in the data. Experimental results with real hyperspectral datasets demonstrate that the proposed algorithm outperforms the state-of-the-art CS-based solutions with substantial reductions in reconstruction error.
[ { "version": "v1", "created": "Tue, 12 Jul 2016 14:49:05 GMT" } ]
2016-07-13T00:00:00
[ [ "Li", "Yangqing", "" ], [ "Prasad", "Saurabh", "" ], [ "Chen", "Wei", "" ], [ "Yin", "Changchuan", "" ], [ "Han", "Zhu", "" ] ]
TITLE: An approximate message passing approach for compressive hyperspectral imaging using a simultaneous low-rank and joint-sparsity prior ABSTRACT: This paper considers a compressive sensing (CS) approach for hyperspectral data acquisition, which results in a practical compression ratio substantially higher than the state-of-the-art. Applying simultaneous low-rank and joint-sparse (L&S) model to the hyperspectral data, we propose a novel algorithm to joint reconstruction of hyperspectral data based on loopy belief propagation that enables the exploitation of both structured sparsity and amplitude correlations in the data. Experimental results with real hyperspectral datasets demonstrate that the proposed algorithm outperforms the state-of-the-art CS-based solutions with substantial reductions in reconstruction error.
1607.03401
Qianqian Xu
Qianqian Xu, Jiechao Xiong, Xiaochun Cao, and Yuan Yao
Parsimonious Mixed-Effects HodgeRank for Crowdsourced Preference Aggregation
10 pages, ACM Multimedia (full paper) accepted
null
null
null
cs.HC cs.LG cs.MM
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In crowdsourced preference aggregation, it is often assumed that all the annotators are subject to a common preference or utility function which generates their comparison behaviors in experiments. However, in reality annotators are subject to variations due to multi-criteria, abnormal, or a mixture of such behaviors. In this paper, we propose a parsimonious mixed-effects model based on HodgeRank, which takes into account both the fixed effect that the majority of annotators follows a common linear utility model, and the random effect that a small subset of annotators might deviate from the common significantly and exhibits strongly personalized preferences. HodgeRank has been successfully applied to subjective quality evaluation of multimedia and resolves pairwise crowdsourced ranking data into a global consensus ranking and cyclic conflicts of interests. As an extension, our proposed methodology further explores the conflicts of interests through the random effect in annotator specific variations. The key algorithm in this paper establishes a dynamic path from the common utility to individual variations, with different levels of parsimony or sparsity on personalization, based on newly developed Linearized Bregman Algorithms with Inverse Scale Space method. Finally the validity of the methodology are supported by experiments with both simulated examples and three real-world crowdsourcing datasets, which shows that our proposed method exhibits better performance (i.e. smaller test error) compared with HodgeRank due to its parsimonious property.
[ { "version": "v1", "created": "Tue, 12 Jul 2016 15:30:10 GMT" } ]
2016-07-13T00:00:00
[ [ "Xu", "Qianqian", "" ], [ "Xiong", "Jiechao", "" ], [ "Cao", "Xiaochun", "" ], [ "Yao", "Yuan", "" ] ]
TITLE: Parsimonious Mixed-Effects HodgeRank for Crowdsourced Preference Aggregation ABSTRACT: In crowdsourced preference aggregation, it is often assumed that all the annotators are subject to a common preference or utility function which generates their comparison behaviors in experiments. However, in reality annotators are subject to variations due to multi-criteria, abnormal, or a mixture of such behaviors. In this paper, we propose a parsimonious mixed-effects model based on HodgeRank, which takes into account both the fixed effect that the majority of annotators follows a common linear utility model, and the random effect that a small subset of annotators might deviate from the common significantly and exhibits strongly personalized preferences. HodgeRank has been successfully applied to subjective quality evaluation of multimedia and resolves pairwise crowdsourced ranking data into a global consensus ranking and cyclic conflicts of interests. As an extension, our proposed methodology further explores the conflicts of interests through the random effect in annotator specific variations. The key algorithm in this paper establishes a dynamic path from the common utility to individual variations, with different levels of parsimony or sparsity on personalization, based on newly developed Linearized Bregman Algorithms with Inverse Scale Space method. Finally the validity of the methodology are supported by experiments with both simulated examples and three real-world crowdsourcing datasets, which shows that our proposed method exhibits better performance (i.e. smaller test error) compared with HodgeRank due to its parsimonious property.
1607.03425
Matthias Vestner
Matthias Vestner, Roee Litman, Alex Bronstein, Emanuele Rodol\`a and Daniel Cremers
Bayesian Inference of Bijective Non-Rigid Shape Correspondence
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Many algorithms for the computation of correspondences between deformable shapes rely on some variant of nearest neighbor matching in a descriptor space. Such are, for example, various point-wise correspondence recovery algorithms used as a postprocessing stage in the functional correspondence framework. In this paper, we show that such frequently used techniques in practice suffer from lack of accuracy and result in poor surjectivity. We propose an alternative recovery technique guaranteeing a bijective correspondence and producing significantly higher accuracy. We derive the proposed method from a statistical framework of Bayesian inference and demonstrate its performance on several challenging deformable 3D shape matching datasets.
[ { "version": "v1", "created": "Tue, 12 Jul 2016 16:04:54 GMT" } ]
2016-07-13T00:00:00
[ [ "Vestner", "Matthias", "" ], [ "Litman", "Roee", "" ], [ "Bronstein", "Alex", "" ], [ "Rodolà", "Emanuele", "" ], [ "Cremers", "Daniel", "" ] ]
TITLE: Bayesian Inference of Bijective Non-Rigid Shape Correspondence ABSTRACT: Many algorithms for the computation of correspondences between deformable shapes rely on some variant of nearest neighbor matching in a descriptor space. Such are, for example, various point-wise correspondence recovery algorithms used as a postprocessing stage in the functional correspondence framework. In this paper, we show that such frequently used techniques in practice suffer from lack of accuracy and result in poor surjectivity. We propose an alternative recovery technique guaranteeing a bijective correspondence and producing significantly higher accuracy. We derive the proposed method from a statistical framework of Bayesian inference and demonstrate its performance on several challenging deformable 3D shape matching datasets.
1607.03456
Moshe Salhov
Amit Bermanis, Aviv Rotbart, Moshe Salhov and Amir Averbuch
Incomplete Pivoted QR-based Dimensionality Reduction
null
null
null
null
cs.LG stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
High-dimensional big data appears in many research fields such as image recognition, biology and collaborative filtering. Often, the exploration of such data by classic algorithms is encountered with difficulties due to `curse of dimensionality' phenomenon. Therefore, dimensionality reduction methods are applied to the data prior to its analysis. Many of these methods are based on principal components analysis, which is statistically driven, namely they map the data into a low-dimension subspace that preserves significant statistical properties of the high-dimensional data. As a consequence, such methods do not directly address the geometry of the data, reflected by the mutual distances between multidimensional data point. Thus, operations such as classification, anomaly detection or other machine learning tasks may be affected. This work provides a dictionary-based framework for geometrically driven data analysis that includes dimensionality reduction, out-of-sample extension and anomaly detection. It embeds high-dimensional data in a low-dimensional subspace. This embedding preserves the original high-dimensional geometry of the data up to a user-defined distortion rate. In addition, it identifies a subset of landmark data points that constitute a dictionary for the analyzed dataset. The dictionary enables to have a natural extension of the low-dimensional embedding to out-of-sample data points, which gives rise to a distortion-based criterion for anomaly detection. The suggested method is demonstrated on synthetic and real-world datasets and achieves good results for classification, anomaly detection and out-of-sample tasks.
[ { "version": "v1", "created": "Tue, 12 Jul 2016 18:20:23 GMT" } ]
2016-07-13T00:00:00
[ [ "Bermanis", "Amit", "" ], [ "Rotbart", "Aviv", "" ], [ "Salhov", "Moshe", "" ], [ "Averbuch", "Amir", "" ] ]
TITLE: Incomplete Pivoted QR-based Dimensionality Reduction ABSTRACT: High-dimensional big data appears in many research fields such as image recognition, biology and collaborative filtering. Often, the exploration of such data by classic algorithms is encountered with difficulties due to `curse of dimensionality' phenomenon. Therefore, dimensionality reduction methods are applied to the data prior to its analysis. Many of these methods are based on principal components analysis, which is statistically driven, namely they map the data into a low-dimension subspace that preserves significant statistical properties of the high-dimensional data. As a consequence, such methods do not directly address the geometry of the data, reflected by the mutual distances between multidimensional data point. Thus, operations such as classification, anomaly detection or other machine learning tasks may be affected. This work provides a dictionary-based framework for geometrically driven data analysis that includes dimensionality reduction, out-of-sample extension and anomaly detection. It embeds high-dimensional data in a low-dimensional subspace. This embedding preserves the original high-dimensional geometry of the data up to a user-defined distortion rate. In addition, it identifies a subset of landmark data points that constitute a dictionary for the analyzed dataset. The dictionary enables to have a natural extension of the low-dimensional embedding to out-of-sample data points, which gives rise to a distortion-based criterion for anomaly detection. The suggested method is demonstrated on synthetic and real-world datasets and achieves good results for classification, anomaly detection and out-of-sample tasks.
1607.03475
Ping Li
Ping Li
Nystrom Method for Approximating the GMM Kernel
null
null
null
null
stat.ML cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The GMM (generalized min-max) kernel was recently proposed (Li, 2016) as a measure of data similarity and was demonstrated effective in machine learning tasks. In order to use the GMM kernel for large-scale datasets, the prior work resorted to the (generalized) consistent weighted sampling (GCWS) to convert the GMM kernel to linear kernel. We call this approach as ``GMM-GCWS''. In the machine learning literature, there is a popular algorithm which we call ``RBF-RFF''. That is, one can use the ``random Fourier features'' (RFF) to convert the ``radial basis function'' (RBF) kernel to linear kernel. It was empirically shown in (Li, 2016) that RBF-RFF typically requires substantially more samples than GMM-GCWS in order to achieve comparable accuracies. The Nystrom method is a general tool for computing nonlinear kernels, which again converts nonlinear kernels into linear kernels. We apply the Nystrom method for approximating the GMM kernel, a strategy which we name as ``GMM-NYS''. In this study, our extensive experiments on a set of fairly large datasets confirm that GMM-NYS is also a strong competitor of RBF-RFF.
[ { "version": "v1", "created": "Tue, 12 Jul 2016 19:42:40 GMT" } ]
2016-07-13T00:00:00
[ [ "Li", "Ping", "" ] ]
TITLE: Nystrom Method for Approximating the GMM Kernel ABSTRACT: The GMM (generalized min-max) kernel was recently proposed (Li, 2016) as a measure of data similarity and was demonstrated effective in machine learning tasks. In order to use the GMM kernel for large-scale datasets, the prior work resorted to the (generalized) consistent weighted sampling (GCWS) to convert the GMM kernel to linear kernel. We call this approach as ``GMM-GCWS''. In the machine learning literature, there is a popular algorithm which we call ``RBF-RFF''. That is, one can use the ``random Fourier features'' (RFF) to convert the ``radial basis function'' (RBF) kernel to linear kernel. It was empirically shown in (Li, 2016) that RBF-RFF typically requires substantially more samples than GMM-GCWS in order to achieve comparable accuracies. The Nystrom method is a general tool for computing nonlinear kernels, which again converts nonlinear kernels into linear kernels. We apply the Nystrom method for approximating the GMM kernel, a strategy which we name as ``GMM-NYS''. In this study, our extensive experiments on a set of fairly large datasets confirm that GMM-NYS is also a strong competitor of RBF-RFF.
1607.00148
Pankaj Malhotra Mr.
Pankaj Malhotra, Anusha Ramakrishnan, Gaurangi Anand, Lovekesh Vig, Puneet Agarwal, Gautam Shroff
LSTM-based Encoder-Decoder for Multi-sensor Anomaly Detection
Accepted at ICML 2016 Anomaly Detection Workshop, New York, NY, USA, 2016. Reference update in this version (v2)
null
null
null
cs.AI cs.LG stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Mechanical devices such as engines, vehicles, aircrafts, etc., are typically instrumented with numerous sensors to capture the behavior and health of the machine. However, there are often external factors or variables which are not captured by sensors leading to time-series which are inherently unpredictable. For instance, manual controls and/or unmonitored environmental conditions or load may lead to inherently unpredictable time-series. Detecting anomalies in such scenarios becomes challenging using standard approaches based on mathematical models that rely on stationarity, or prediction models that utilize prediction errors to detect anomalies. We propose a Long Short Term Memory Networks based Encoder-Decoder scheme for Anomaly Detection (EncDec-AD) that learns to reconstruct 'normal' time-series behavior, and thereafter uses reconstruction error to detect anomalies. We experiment with three publicly available quasi predictable time-series datasets: power demand, space shuttle, and ECG, and two real-world engine datasets with both predictive and unpredictable behavior. We show that EncDec-AD is robust and can detect anomalies from predictable, unpredictable, periodic, aperiodic, and quasi-periodic time-series. Further, we show that EncDec-AD is able to detect anomalies from short time-series (length as small as 30) as well as long time-series (length as large as 500).
[ { "version": "v1", "created": "Fri, 1 Jul 2016 08:25:48 GMT" }, { "version": "v2", "created": "Mon, 11 Jul 2016 09:33:48 GMT" } ]
2016-07-12T00:00:00
[ [ "Malhotra", "Pankaj", "" ], [ "Ramakrishnan", "Anusha", "" ], [ "Anand", "Gaurangi", "" ], [ "Vig", "Lovekesh", "" ], [ "Agarwal", "Puneet", "" ], [ "Shroff", "Gautam", "" ] ]
TITLE: LSTM-based Encoder-Decoder for Multi-sensor Anomaly Detection ABSTRACT: Mechanical devices such as engines, vehicles, aircrafts, etc., are typically instrumented with numerous sensors to capture the behavior and health of the machine. However, there are often external factors or variables which are not captured by sensors leading to time-series which are inherently unpredictable. For instance, manual controls and/or unmonitored environmental conditions or load may lead to inherently unpredictable time-series. Detecting anomalies in such scenarios becomes challenging using standard approaches based on mathematical models that rely on stationarity, or prediction models that utilize prediction errors to detect anomalies. We propose a Long Short Term Memory Networks based Encoder-Decoder scheme for Anomaly Detection (EncDec-AD) that learns to reconstruct 'normal' time-series behavior, and thereafter uses reconstruction error to detect anomalies. We experiment with three publicly available quasi predictable time-series datasets: power demand, space shuttle, and ECG, and two real-world engine datasets with both predictive and unpredictable behavior. We show that EncDec-AD is robust and can detect anomalies from predictable, unpredictable, periodic, aperiodic, and quasi-periodic time-series. Further, we show that EncDec-AD is able to detect anomalies from short time-series (length as small as 30) as well as long time-series (length as large as 500).
1607.02556
Jialin Wu
Jialin Wu, Gu Wang, Wukui Yang, Xiangyang Ji
Action Recognition with Joint Attention on Multi-Level Deep Features
13 pages, submitted to BMVC
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a novel deep supervised neural network for the task of action recognition in videos, which implicitly takes advantage of visual tracking and shares the robustness of both deep Convolutional Neural Network (CNN) and Recurrent Neural Network (RNN). In our method, a multi-branch model is proposed to suppress noise from background jitters. Specifically, we firstly extract multi-level deep features from deep CNNs and feed them into 3d-convolutional network. After that we feed those feature cubes into our novel joint LSTM module to predict labels and to generate attention regularization. We evaluate our model on two challenging datasets: UCF101 and HMDB51. The results show that our model achieves the state-of-art by only using convolutional features.
[ { "version": "v1", "created": "Sat, 9 Jul 2016 01:25:24 GMT" } ]
2016-07-12T00:00:00
[ [ "Wu", "Jialin", "" ], [ "Wang", "Gu", "" ], [ "Yang", "Wukui", "" ], [ "Ji", "Xiangyang", "" ] ]
TITLE: Action Recognition with Joint Attention on Multi-Level Deep Features ABSTRACT: We propose a novel deep supervised neural network for the task of action recognition in videos, which implicitly takes advantage of visual tracking and shares the robustness of both deep Convolutional Neural Network (CNN) and Recurrent Neural Network (RNN). In our method, a multi-branch model is proposed to suppress noise from background jitters. Specifically, we firstly extract multi-level deep features from deep CNNs and feed them into 3d-convolutional network. After that we feed those feature cubes into our novel joint LSTM module to predict labels and to generate attention regularization. We evaluate our model on two challenging datasets: UCF101 and HMDB51. The results show that our model achieves the state-of-art by only using convolutional features.
1607.02559
Xiaojun Chang
Sen Wang and Feiping Nie and Xiaojun Chang and Xue Li and Quan Z. Sheng and Lina Yao
Uncovering Locally Discriminative Structure for Feature Analysis
Accepted by ECML/PKDD2016
null
null
null
cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Manifold structure learning is often used to exploit geometric information among data in semi-supervised feature learning algorithms. In this paper, we find that local discriminative information is also of importance for semi-supervised feature learning. We propose a method that utilizes both the manifold structure of data and local discriminant information. Specifically, we define a local clique for each data point. The k-Nearest Neighbors (kNN) is used to determine the structural information within each clique. We then employ a variant of Fisher criterion model to each clique for local discriminant evaluation and sum all cliques as global integration into the framework. In this way, local discriminant information is embedded. Labels are also utilized to minimize distances between data from the same class. In addition, we use the kernel method to extend our proposed model and facilitate feature learning in a high-dimensional space after feature mapping. Experimental results show that our method is superior to all other compared methods over a number of datasets.
[ { "version": "v1", "created": "Sat, 9 Jul 2016 02:29:53 GMT" } ]
2016-07-12T00:00:00
[ [ "Wang", "Sen", "" ], [ "Nie", "Feiping", "" ], [ "Chang", "Xiaojun", "" ], [ "Li", "Xue", "" ], [ "Sheng", "Quan Z.", "" ], [ "Yao", "Lina", "" ] ]
TITLE: Uncovering Locally Discriminative Structure for Feature Analysis ABSTRACT: Manifold structure learning is often used to exploit geometric information among data in semi-supervised feature learning algorithms. In this paper, we find that local discriminative information is also of importance for semi-supervised feature learning. We propose a method that utilizes both the manifold structure of data and local discriminant information. Specifically, we define a local clique for each data point. The k-Nearest Neighbors (kNN) is used to determine the structural information within each clique. We then employ a variant of Fisher criterion model to each clique for local discriminant evaluation and sum all cliques as global integration into the framework. In this way, local discriminant information is embedded. Labels are also utilized to minimize distances between data from the same class. In addition, we use the kernel method to extend our proposed model and facilitate feature learning in a high-dimensional space after feature mapping. Experimental results show that our method is superior to all other compared methods over a number of datasets.
1607.02643
Mostafa Ibrahim Mostafa Ibrahim
Mostafa S. Ibrahim, Srikanth Muralidharan, Zhiwei Deng, Arash Vahdat, Greg Mori
Hierarchical Deep Temporal Models for Group Activity Recognition
arXiv admin note: text overlap with arXiv:1511.06040
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we present an approach for classifying the activity performed by a group of people in a video sequence. This problem of group activity recognition can be addressed by examining individual person actions and their relations. Temporal dynamics exist both at the level of individual person actions as well as at the level of group activity. Given a video sequence as input, methods can be developed to capture these dynamics at both person-level and group-level detail. We build a deep model to capture these dynamics based on LSTM (long short-term memory) models. In order to model both person-level and group-level dynamics, we present a 2-stage deep temporal model for the group activity recognition problem. In our approach, one LSTM model is designed to represent action dynamics of individual people in a video sequence and another LSTM model is designed to aggregate person-level information for group activity recognition. We collected a new dataset consisting of volleyball videos labeled with individual and group activities in order to evaluate our method. Experimental results on this new Volleyball Dataset and the standard benchmark Collective Activity Dataset demonstrate the efficacy of the proposed models.
[ { "version": "v1", "created": "Sat, 9 Jul 2016 18:23:36 GMT" } ]
2016-07-12T00:00:00
[ [ "Ibrahim", "Mostafa S.", "" ], [ "Muralidharan", "Srikanth", "" ], [ "Deng", "Zhiwei", "" ], [ "Vahdat", "Arash", "" ], [ "Mori", "Greg", "" ] ]
TITLE: Hierarchical Deep Temporal Models for Group Activity Recognition ABSTRACT: In this paper we present an approach for classifying the activity performed by a group of people in a video sequence. This problem of group activity recognition can be addressed by examining individual person actions and their relations. Temporal dynamics exist both at the level of individual person actions as well as at the level of group activity. Given a video sequence as input, methods can be developed to capture these dynamics at both person-level and group-level detail. We build a deep model to capture these dynamics based on LSTM (long short-term memory) models. In order to model both person-level and group-level dynamics, we present a 2-stage deep temporal model for the group activity recognition problem. In our approach, one LSTM model is designed to represent action dynamics of individual people in a video sequence and another LSTM model is designed to aggregate person-level information for group activity recognition. We collected a new dataset consisting of volleyball videos labeled with individual and group activities in order to evaluate our method. Experimental results on this new Volleyball Dataset and the standard benchmark Collective Activity Dataset demonstrate the efficacy of the proposed models.
1607.02678
Wei Li
Wei Li, Farnaz Abtahi, Christina Tsangouri, Zhigang Zhu
Towards an "In-the-Wild" Emotion Dataset Using a Game-based Framework
This paper is accepted at CVPR 2016 Workshop
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In order to create an "in-the-wild" dataset of facial emotions with large number of balanced samples, this paper proposes a game-based data collection framework. The framework mainly include three components: a game engine, a game interface, and a data collection and evaluation module. We use a deep learning approach to build an emotion classifier as the game engine. Then a emotion web game to allow gamers to enjoy the games, while the data collection module obtains automatically-labelled emotion images. Using our game, we have collected more than 15,000 images within a month of the test run and built an emotion dataset "GaMo". To evaluate the dataset, we compared the performance of two deep learning models trained on both GaMo and CIFE. The results of our experiments show that because of being large and balanced, GaMo can be used to build a more robust emotion detector than the emotion detector trained on CIFE, which was used in the game engine to collect the face images.
[ { "version": "v1", "created": "Sun, 10 Jul 2016 02:16:10 GMT" } ]
2016-07-12T00:00:00
[ [ "Li", "Wei", "" ], [ "Abtahi", "Farnaz", "" ], [ "Tsangouri", "Christina", "" ], [ "Zhu", "Zhigang", "" ] ]
TITLE: Towards an "In-the-Wild" Emotion Dataset Using a Game-based Framework ABSTRACT: In order to create an "in-the-wild" dataset of facial emotions with large number of balanced samples, this paper proposes a game-based data collection framework. The framework mainly include three components: a game engine, a game interface, and a data collection and evaluation module. We use a deep learning approach to build an emotion classifier as the game engine. Then a emotion web game to allow gamers to enjoy the games, while the data collection module obtains automatically-labelled emotion images. Using our game, we have collected more than 15,000 images within a month of the test run and built an emotion dataset "GaMo". To evaluate the dataset, we compared the performance of two deep learning models trained on both GaMo and CIFE. The results of our experiments show that because of being large and balanced, GaMo can be used to build a more robust emotion detector than the emotion detector trained on CIFE, which was used in the game engine to collect the face images.
1607.02769
Gitit Kehat
Gitit Kehat and James Pustejovsky
Annotation Methodologies for Vision and Language Dataset Creation
in Scene Understanding Workshop (SUNw) in CVPR 2016
null
null
null
cs.CV cs.CL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Annotated datasets are commonly used in the training and evaluation of tasks involving natural language and vision (image description generation, action recognition and visual question answering). However, many of the existing datasets reflect problems that emerge in the process of data selection and annotation. Here we point out some of the difficulties and problems one confronts when creating and validating annotated vision and language datasets.
[ { "version": "v1", "created": "Sun, 10 Jul 2016 18:11:27 GMT" } ]
2016-07-12T00:00:00
[ [ "Kehat", "Gitit", "" ], [ "Pustejovsky", "James", "" ] ]
TITLE: Annotation Methodologies for Vision and Language Dataset Creation ABSTRACT: Annotated datasets are commonly used in the training and evaluation of tasks involving natural language and vision (image description generation, action recognition and visual question answering). However, many of the existing datasets reflect problems that emerge in the process of data selection and annotation. Here we point out some of the difficulties and problems one confronts when creating and validating annotated vision and language datasets.
1607.02802
Franck Dernoncourt
Franck Dernoncourt
Mapping distributional to model-theoretic semantic spaces: a baseline
null
null
null
null
cs.CL cs.AI stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Word embeddings have been shown to be useful across state-of-the-art systems in many natural language processing tasks, ranging from question answering systems to dependency parsing. (Herbelot and Vecchi, 2015) explored word embeddings and their utility for modeling language semantics. In particular, they presented an approach to automatically map a standard distributional semantic space onto a set-theoretic model using partial least squares regression. We show in this paper that a simple baseline achieves a +51% relative improvement compared to their model on one of the two datasets they used, and yields competitive results on the second dataset.
[ { "version": "v1", "created": "Mon, 11 Jul 2016 01:20:57 GMT" } ]
2016-07-12T00:00:00
[ [ "Dernoncourt", "Franck", "" ] ]
TITLE: Mapping distributional to model-theoretic semantic spaces: a baseline ABSTRACT: Word embeddings have been shown to be useful across state-of-the-art systems in many natural language processing tasks, ranging from question answering systems to dependency parsing. (Herbelot and Vecchi, 2015) explored word embeddings and their utility for modeling language semantics. In particular, they presented an approach to automatically map a standard distributional semantic space onto a set-theoretic model using partial least squares regression. We show in this paper that a simple baseline achieves a +51% relative improvement compared to their model on one of the two datasets they used, and yields competitive results on the second dataset.
1607.02815
Chao-Yeh Chen
Chao-Yeh Chen and Kristen Grauman
Efficient Activity Detection in Untrimmed Video with Max-Subgraph Search
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose an efficient approach for activity detection in video that unifies activity categorization with space-time localization. The main idea is to pose activity detection as a maximum-weight connected subgraph problem. Offline, we learn a binary classifier for an activity category using positive video exemplars that are "trimmed" in time to the activity of interest. Then, given a novel \emph{untrimmed} video sequence, we decompose it into a 3D array of space-time nodes, which are weighted based on the extent to which their component features support the learned activity model. To perform detection, we then directly localize instances of the activity by solving for the maximum-weight connected subgraph in the test video's space-time graph. We show that this detection strategy permits an efficient branch-and-cut solution for the best-scoring---and possibly non-cubically shaped---portion of the video for a given activity classifier. The upshot is a fast method that can search a broader space of space-time region candidates than was previously practical, which we find often leads to more accurate detection. We demonstrate the proposed algorithm on four datasets, and we show its speed and accuracy advantages over multiple existing search strategies.
[ { "version": "v1", "created": "Mon, 11 Jul 2016 03:48:21 GMT" } ]
2016-07-12T00:00:00
[ [ "Chen", "Chao-Yeh", "" ], [ "Grauman", "Kristen", "" ] ]
TITLE: Efficient Activity Detection in Untrimmed Video with Max-Subgraph Search ABSTRACT: We propose an efficient approach for activity detection in video that unifies activity categorization with space-time localization. The main idea is to pose activity detection as a maximum-weight connected subgraph problem. Offline, we learn a binary classifier for an activity category using positive video exemplars that are "trimmed" in time to the activity of interest. Then, given a novel \emph{untrimmed} video sequence, we decompose it into a 3D array of space-time nodes, which are weighted based on the extent to which their component features support the learned activity model. To perform detection, we then directly localize instances of the activity by solving for the maximum-weight connected subgraph in the test video's space-time graph. We show that this detection strategy permits an efficient branch-and-cut solution for the best-scoring---and possibly non-cubically shaped---portion of the video for a given activity classifier. The upshot is a fast method that can search a broader space of space-time region candidates than was previously practical, which we find often leads to more accurate detection. We demonstrate the proposed algorithm on four datasets, and we show its speed and accuracy advantages over multiple existing search strategies.
1607.02858
Takuya Kitazawa
Takuya Kitazawa
Incremental Factorization Machines for Persistently Cold-starting Online Item Recommendation
4 pages, 6 figures, The 1st Workshop on Profiling User Preferences for Dynamic Online and Real-Time Recommendations, RecSys 2016
null
null
null
cs.LG cs.IR
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Real-world item recommenders commonly suffer from a persistent cold-start problem which is caused by dynamically changing users and items. In order to overcome the problem, several context-aware recommendation techniques have been recently proposed. In terms of both feasibility and performance, factorization machine (FM) is one of the most promising methods as generalization of the conventional matrix factorization techniques. However, since online algorithms are suitable for dynamic data, the static FMs are still inadequate. Thus, this paper proposes incremental FMs (iFMs), a general online factorization framework, and specially extends iFMs into an online item recommender. The proposed framework can be a promising baseline for further development of the production recommender systems. Evaluation is done empirically both on synthetic and real-world unstable datasets.
[ { "version": "v1", "created": "Mon, 11 Jul 2016 08:37:42 GMT" } ]
2016-07-12T00:00:00
[ [ "Kitazawa", "Takuya", "" ] ]
TITLE: Incremental Factorization Machines for Persistently Cold-starting Online Item Recommendation ABSTRACT: Real-world item recommenders commonly suffer from a persistent cold-start problem which is caused by dynamically changing users and items. In order to overcome the problem, several context-aware recommendation techniques have been recently proposed. In terms of both feasibility and performance, factorization machine (FM) is one of the most promising methods as generalization of the conventional matrix factorization techniques. However, since online algorithms are suitable for dynamic data, the static FMs are still inadequate. Thus, this paper proposes incremental FMs (iFMs), a general online factorization framework, and specially extends iFMs into an online item recommender. The proposed framework can be a promising baseline for further development of the production recommender systems. Evaluation is done empirically both on synthetic and real-world unstable datasets.
1607.03050
Daniel Jiwoong Im
Daniel Jiwoong Im, Graham W. Taylor
Learning a metric for class-conditional KNN
null
null
null
null
cs.LG stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Naive Bayes Nearest Neighbour (NBNN) is a simple and effective framework which addresses many of the pitfalls of K-Nearest Neighbour (KNN) classification. It has yielded competitive results on several computer vision benchmarks. Its central tenet is that during NN search, a query is not compared to every example in a database, ignoring class information. Instead, NN searches are performed within each class, generating a score per class. A key problem with NN techniques, including NBNN, is that they fail when the data representation does not capture perceptual (e.g.~class-based) similarity. NBNN circumvents this by using independent engineered descriptors (e.g.~SIFT). To extend its applicability outside of image-based domains, we propose to learn a metric which captures perceptual similarity. Similar to how Neighbourhood Components Analysis optimizes a differentiable form of KNN classification, we propose "Class Conditional" metric learning (CCML), which optimizes a soft form of the NBNN selection rule. Typical metric learning algorithms learn either a global or local metric. However, our proposed method can be adjusted to a particular level of locality by tuning a single parameter. An empirical evaluation on classification and retrieval tasks demonstrates that our proposed method clearly outperforms existing learned distance metrics across a variety of image and non-image datasets.
[ { "version": "v1", "created": "Mon, 11 Jul 2016 17:29:19 GMT" } ]
2016-07-12T00:00:00
[ [ "Im", "Daniel Jiwoong", "" ], [ "Taylor", "Graham W.", "" ] ]
TITLE: Learning a metric for class-conditional KNN ABSTRACT: Naive Bayes Nearest Neighbour (NBNN) is a simple and effective framework which addresses many of the pitfalls of K-Nearest Neighbour (KNN) classification. It has yielded competitive results on several computer vision benchmarks. Its central tenet is that during NN search, a query is not compared to every example in a database, ignoring class information. Instead, NN searches are performed within each class, generating a score per class. A key problem with NN techniques, including NBNN, is that they fail when the data representation does not capture perceptual (e.g.~class-based) similarity. NBNN circumvents this by using independent engineered descriptors (e.g.~SIFT). To extend its applicability outside of image-based domains, we propose to learn a metric which captures perceptual similarity. Similar to how Neighbourhood Components Analysis optimizes a differentiable form of KNN classification, we propose "Class Conditional" metric learning (CCML), which optimizes a soft form of the NBNN selection rule. Typical metric learning algorithms learn either a global or local metric. However, our proposed method can be adjusted to a particular level of locality by tuning a single parameter. An empirical evaluation on classification and retrieval tasks demonstrates that our proposed method clearly outperforms existing learned distance metrics across a variety of image and non-image datasets.
1607.03057
Pedro Saleiro
Pedro Saleiro, Carlos Soares
Learning from the News: Predicting Entity Popularity on Twitter
null
null
null
null
cs.SI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work, we tackle the problem of predicting entity popularity on Twitter based on the news cycle. We apply a supervised learn- ing approach and extract four types of features: (i) signal, (ii) textual, (iii) sentiment and (iv) semantic, which we use to predict whether the popularity of a given entity will be high or low in the following hours. We run several experiments on six different entities in a dataset of over 150M tweets and 5M news and obtained F1 scores over 0.70. Error analysis indicates that news perform better on predicting entity popularity on Twitter when they are the primary information source of the event, in opposition to events such as live TV broadcasts, political debates or football matches.
[ { "version": "v1", "created": "Mon, 11 Jul 2016 17:53:27 GMT" } ]
2016-07-12T00:00:00
[ [ "Saleiro", "Pedro", "" ], [ "Soares", "Carlos", "" ] ]
TITLE: Learning from the News: Predicting Entity Popularity on Twitter ABSTRACT: In this work, we tackle the problem of predicting entity popularity on Twitter based on the news cycle. We apply a supervised learn- ing approach and extract four types of features: (i) signal, (ii) textual, (iii) sentiment and (iv) semantic, which we use to predict whether the popularity of a given entity will be high or low in the following hours. We run several experiments on six different entities in a dataset of over 150M tweets and 5M news and obtained F1 scores over 0.70. Error analysis indicates that news perform better on predicting entity popularity on Twitter when they are the primary information source of the event, in opposition to events such as live TV broadcasts, political debates or football matches.
1502.06470
Eric Tramel
Eric W. Tramel and Ang\'elique Dr\'emeau and Florent Krzakala
Approximate Message Passing with Restricted Boltzmann Machine Priors
null
J. Stat. Mech. (2016) 073401
10.1088/1742-5468/2016/07/073401
null
cs.IT cond-mat.dis-nn math.IT physics.data-an stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Approximate Message Passing (AMP) has been shown to be an excellent statistical approach to signal inference and compressed sensing problem. The AMP framework provides modularity in the choice of signal prior; here we propose a hierarchical form of the Gauss-Bernouilli prior which utilizes a Restricted Boltzmann Machine (RBM) trained on the signal support to push reconstruction performance beyond that of simple iid priors for signals whose support can be well represented by a trained binary RBM. We present and analyze two methods of RBM factorization and demonstrate how these affect signal reconstruction performance within our proposed algorithm. Finally, using the MNIST handwritten digit dataset, we show experimentally that using an RBM allows AMP to approach oracle-support performance.
[ { "version": "v1", "created": "Mon, 23 Feb 2015 15:51:07 GMT" }, { "version": "v2", "created": "Tue, 9 Jun 2015 14:05:45 GMT" }, { "version": "v3", "created": "Thu, 10 Dec 2015 03:45:32 GMT" } ]
2016-07-11T00:00:00
[ [ "Tramel", "Eric W.", "" ], [ "Drémeau", "Angélique", "" ], [ "Krzakala", "Florent", "" ] ]
TITLE: Approximate Message Passing with Restricted Boltzmann Machine Priors ABSTRACT: Approximate Message Passing (AMP) has been shown to be an excellent statistical approach to signal inference and compressed sensing problem. The AMP framework provides modularity in the choice of signal prior; here we propose a hierarchical form of the Gauss-Bernouilli prior which utilizes a Restricted Boltzmann Machine (RBM) trained on the signal support to push reconstruction performance beyond that of simple iid priors for signals whose support can be well represented by a trained binary RBM. We present and analyze two methods of RBM factorization and demonstrate how these affect signal reconstruction performance within our proposed algorithm. Finally, using the MNIST handwritten digit dataset, we show experimentally that using an RBM allows AMP to approach oracle-support performance.
1511.02136
James Atwood
James Atwood and Don Towsley
Diffusion-Convolutional Neural Networks
Full paper
null
null
null
cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present diffusion-convolutional neural networks (DCNNs), a new model for graph-structured data. Through the introduction of a diffusion-convolution operation, we show how diffusion-based representations can be learned from graph-structured data and used as an effective basis for node classification. DCNNs have several attractive qualities, including a latent representation for graphical data that is invariant under isomorphism, as well as polynomial-time prediction and learning that can be represented as tensor operations and efficiently implemented on the GPU. Through several experiments with real structured datasets, we demonstrate that DCNNs are able to outperform probabilistic relational models and kernel-on-graph methods at relational node classification tasks.
[ { "version": "v1", "created": "Fri, 6 Nov 2015 16:09:32 GMT" }, { "version": "v2", "created": "Mon, 16 Nov 2015 14:33:30 GMT" }, { "version": "v3", "created": "Fri, 20 Nov 2015 14:38:08 GMT" }, { "version": "v4", "created": "Thu, 7 Jan 2016 19:33:18 GMT" }, { "version": "v5", "created": "Tue, 19 Jan 2016 20:36:29 GMT" }, { "version": "v6", "created": "Fri, 8 Jul 2016 15:05:17 GMT" } ]
2016-07-11T00:00:00
[ [ "Atwood", "James", "" ], [ "Towsley", "Don", "" ] ]
TITLE: Diffusion-Convolutional Neural Networks ABSTRACT: We present diffusion-convolutional neural networks (DCNNs), a new model for graph-structured data. Through the introduction of a diffusion-convolution operation, we show how diffusion-based representations can be learned from graph-structured data and used as an effective basis for node classification. DCNNs have several attractive qualities, including a latent representation for graphical data that is invariant under isomorphism, as well as polynomial-time prediction and learning that can be represented as tensor operations and efficiently implemented on the GPU. Through several experiments with real structured datasets, we demonstrate that DCNNs are able to outperform probabilistic relational models and kernel-on-graph methods at relational node classification tasks.
1511.05065
Bumsub Ham
Bumsub Ham, Minsu Cho, Cordelia Schmid, Jean Ponce
Proposal Flow
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Finding image correspondences remains a challenging problem in the presence of intra-class variations and large changes in scene layout.~Semantic flow methods are designed to handle images depicting different instances of the same object or scene category. We introduce a novel approach to semantic flow, dubbed proposal flow, that establishes reliable correspondences using object proposals. Unlike prevailing semantic flow approaches that operate on pixels or regularly sampled local regions, proposal flow benefits from the characteristics of modern object proposals, that exhibit high repeatability at multiple scales, and can take advantage of both local and geometric consistency constraints among proposals. We also show that proposal flow can effectively be transformed into a conventional dense flow field. We introduce a new dataset that can be used to evaluate both general semantic flow techniques and region-based approaches such as proposal flow. We use this benchmark to compare different matching algorithms, object proposals, and region features within proposal flow, to the state of the art in semantic flow. This comparison, along with experiments on standard datasets, demonstrates that proposal flow significantly outperforms existing semantic flow methods in various settings.
[ { "version": "v1", "created": "Mon, 16 Nov 2015 17:54:45 GMT" }, { "version": "v2", "created": "Fri, 4 Mar 2016 16:19:40 GMT" }, { "version": "v3", "created": "Fri, 8 Jul 2016 18:32:37 GMT" } ]
2016-07-11T00:00:00
[ [ "Ham", "Bumsub", "" ], [ "Cho", "Minsu", "" ], [ "Schmid", "Cordelia", "" ], [ "Ponce", "Jean", "" ] ]
TITLE: Proposal Flow ABSTRACT: Finding image correspondences remains a challenging problem in the presence of intra-class variations and large changes in scene layout.~Semantic flow methods are designed to handle images depicting different instances of the same object or scene category. We introduce a novel approach to semantic flow, dubbed proposal flow, that establishes reliable correspondences using object proposals. Unlike prevailing semantic flow approaches that operate on pixels or regularly sampled local regions, proposal flow benefits from the characteristics of modern object proposals, that exhibit high repeatability at multiple scales, and can take advantage of both local and geometric consistency constraints among proposals. We also show that proposal flow can effectively be transformed into a conventional dense flow field. We introduce a new dataset that can be used to evaluate both general semantic flow techniques and region-based approaches such as proposal flow. We use this benchmark to compare different matching algorithms, object proposals, and region features within proposal flow, to the state of the art in semantic flow. This comparison, along with experiments on standard datasets, demonstrates that proposal flow significantly outperforms existing semantic flow methods in various settings.
1511.05292
Jinghua Wang
Jinghua Wang, Gang Wang
Hierarchical Spatial Sum-Product Networks for Action Recognition in Still Images
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recognizing actions from still images is popularly studied recently. In this paper, we model an action class as a flexible number of spatial configurations of body parts by proposing a new spatial SPN (Sum-Product Networks). First, we discover a set of parts in image collections via unsupervised learning. Then, our new spatial SPN is applied to model the spatial relationship and also the high-order correlations of parts. To learn robust networks, we further develop a hierarchical spatial SPN method, which models pairwise spatial relationship between parts inside sub-images and models the correlation of sub-images via extra layers of SPN. Our method is shown to be effective on two benchmark datasets.
[ { "version": "v1", "created": "Tue, 17 Nov 2015 07:21:20 GMT" }, { "version": "v2", "created": "Mon, 23 Nov 2015 07:29:25 GMT" }, { "version": "v3", "created": "Fri, 8 Jul 2016 01:41:41 GMT" } ]
2016-07-11T00:00:00
[ [ "Wang", "Jinghua", "" ], [ "Wang", "Gang", "" ] ]
TITLE: Hierarchical Spatial Sum-Product Networks for Action Recognition in Still Images ABSTRACT: Recognizing actions from still images is popularly studied recently. In this paper, we model an action class as a flexible number of spatial configurations of body parts by proposing a new spatial SPN (Sum-Product Networks). First, we discover a set of parts in image collections via unsupervised learning. Then, our new spatial SPN is applied to model the spatial relationship and also the high-order correlations of parts. To learn robust networks, we further develop a hierarchical spatial SPN method, which models pairwise spatial relationship between parts inside sub-images and models the correlation of sub-images via extra layers of SPN. Our method is shown to be effective on two benchmark datasets.
1605.02112
Seyoung Park
Seyoung Park, Bruce Xiaohan Nie, Song-Chun Zhu
Attribute And-Or Grammar for Joint Parsing of Human Attributes, Part and Pose
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper presents an attribute and-or grammar (A-AOG) model for jointly inferring human body pose and human attributes in a parse graph with attributes augmented to nodes in the hierarchical representation. In contrast to other popular methods in the current literature that train separate classifiers for poses and individual attributes, our method explicitly represents the decomposition and articulation of body parts, and account for the correlations between poses and attributes. The A-AOG model is an amalgamation of three traditional grammar formulations: (i) Phrase structure grammar representing the hierarchical decomposition of the human body from whole to parts; (ii) Dependency grammar modeling the geometric articulation by a kinematic graph of the body pose; and (iii) Attribute grammar accounting for the compatibility relations between different parts in the hierarchy so that their appearances follow a consistent style. The parse graph outputs human detection, pose estimation, and attribute prediction simultaneously, which are intuitive and interpretable. We conduct experiments on two tasks on two datasets, and experimental results demonstrate the advantage of joint modeling in comparison with computing poses and attributes independently. Furthermore, our model obtains better performance over existing methods for both pose estimation and attribute prediction tasks.
[ { "version": "v1", "created": "Fri, 6 May 2016 22:23:41 GMT" }, { "version": "v2", "created": "Thu, 7 Jul 2016 20:10:52 GMT" } ]
2016-07-11T00:00:00
[ [ "Park", "Seyoung", "" ], [ "Nie", "Bruce Xiaohan", "" ], [ "Zhu", "Song-Chun", "" ] ]
TITLE: Attribute And-Or Grammar for Joint Parsing of Human Attributes, Part and Pose ABSTRACT: This paper presents an attribute and-or grammar (A-AOG) model for jointly inferring human body pose and human attributes in a parse graph with attributes augmented to nodes in the hierarchical representation. In contrast to other popular methods in the current literature that train separate classifiers for poses and individual attributes, our method explicitly represents the decomposition and articulation of body parts, and account for the correlations between poses and attributes. The A-AOG model is an amalgamation of three traditional grammar formulations: (i) Phrase structure grammar representing the hierarchical decomposition of the human body from whole to parts; (ii) Dependency grammar modeling the geometric articulation by a kinematic graph of the body pose; and (iii) Attribute grammar accounting for the compatibility relations between different parts in the hierarchy so that their appearances follow a consistent style. The parse graph outputs human detection, pose estimation, and attribute prediction simultaneously, which are intuitive and interpretable. We conduct experiments on two tasks on two datasets, and experimental results demonstrate the advantage of joint modeling in comparison with computing poses and attributes independently. Furthermore, our model obtains better performance over existing methods for both pose estimation and attribute prediction tasks.
1607.02171
Eric Nunes
Eric Nunes, Paulo Shakarian, Gerardo I. Simari, Andrew Ruef
Argumentation Models for Cyber Attribution
8 pages paper to be presented at International Symposium on Foundations of Open Source Intelligence and Security Informatics (FOSINT-SI) 2016 In conjunction with ASONAM 2016 San Francisco, CA, USA, August 19-20, 2016
null
null
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A major challenge in cyber-threat analysis is combining information from different sources to find the person or the group responsible for the cyber-attack. It is one of the most important technical and policy challenges in cyber-security. The lack of ground truth for an individual responsible for an attack has limited previous studies. In this paper, we take a first step towards overcoming this limitation by building a dataset from the capture-the-flag event held at DEFCON, and propose an argumentation model based on a formal reasoning framework called DeLP (Defeasible Logic Programming) designed to aid an analyst in attributing a cyber-attack. We build models from latent variables to reduce the search space of culprits (attackers), and show that this reduction significantly improves the performance of classification-based approaches from 37% to 62% in identifying the attacker.
[ { "version": "v1", "created": "Thu, 7 Jul 2016 21:01:06 GMT" } ]
2016-07-11T00:00:00
[ [ "Nunes", "Eric", "" ], [ "Shakarian", "Paulo", "" ], [ "Simari", "Gerardo I.", "" ], [ "Ruef", "Andrew", "" ] ]
TITLE: Argumentation Models for Cyber Attribution ABSTRACT: A major challenge in cyber-threat analysis is combining information from different sources to find the person or the group responsible for the cyber-attack. It is one of the most important technical and policy challenges in cyber-security. The lack of ground truth for an individual responsible for an attack has limited previous studies. In this paper, we take a first step towards overcoming this limitation by building a dataset from the capture-the-flag event held at DEFCON, and propose an argumentation model based on a formal reasoning framework called DeLP (Defeasible Logic Programming) designed to aid an analyst in attributing a cyber-attack. We build models from latent variables to reduce the search space of culprits (attackers), and show that this reduction significantly improves the performance of classification-based approaches from 37% to 62% in identifying the attacker.
1607.02174
Faiza Khattak Faiza Khattak
Faiza Khan Khattak, Ansaf Salleb-Aouissi
Toward a Robust Crowd-labeling Framework using Expert Evaluation and Pairwise Comparison
null
null
null
null
cs.HC
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Crowd-labeling emerged from the need to label large-scale and complex data, a tedious, expensive, and time-consuming task. One of the main challenges in the crowd-labeling task is to control for or determine in advance the proportion of low-quality/malicious labelers. If that proportion grows too high, there is often a phase transition leading to a steep, non-linear drop in labeling accuracy as noted by Karger et al. [2014]. To address these challenges, we propose a new framework called Expert Label Injected Crowd Estimation (ELICE) and extend it to different versions and variants that delay phase transition leading to a better labeling accuracy. ELICE automatically combines and boosts bulk crowd labels supported by labels from experts for limited number of instances from the dataset. The expert-labels help to estimate the individual ability of crowd labelers and difficulty of each instance, both of which are used to aggregate the labels. Empirical evaluation shows the superiority of ELICE as compared to other state-of-the-art methods. We also derive a lower bound on the number of expert-labeled instances needed to estimate the crowd ability and dataset difficulty as well as to get better quality labels.
[ { "version": "v1", "created": "Thu, 7 Jul 2016 21:23:20 GMT" } ]
2016-07-11T00:00:00
[ [ "Khattak", "Faiza Khan", "" ], [ "Salleb-Aouissi", "Ansaf", "" ] ]
TITLE: Toward a Robust Crowd-labeling Framework using Expert Evaluation and Pairwise Comparison ABSTRACT: Crowd-labeling emerged from the need to label large-scale and complex data, a tedious, expensive, and time-consuming task. One of the main challenges in the crowd-labeling task is to control for or determine in advance the proportion of low-quality/malicious labelers. If that proportion grows too high, there is often a phase transition leading to a steep, non-linear drop in labeling accuracy as noted by Karger et al. [2014]. To address these challenges, we propose a new framework called Expert Label Injected Crowd Estimation (ELICE) and extend it to different versions and variants that delay phase transition leading to a better labeling accuracy. ELICE automatically combines and boosts bulk crowd labels supported by labels from experts for limited number of instances from the dataset. The expert-labels help to estimate the individual ability of crowd labelers and difficulty of each instance, both of which are used to aggregate the labels. Empirical evaluation shows the superiority of ELICE as compared to other state-of-the-art methods. We also derive a lower bound on the number of expert-labeled instances needed to estimate the crowd ability and dataset difficulty as well as to get better quality labels.
1607.02257
Rigas Kouskouridas
Andreas Doumanoglou, Vassileios Balntas, Rigas Kouskouridas, Tae-Kyun Kim
Siamese Regression Networks with Efficient mid-level Feature Extraction for 3D Object Pose Estimation
9 pages, paper submitted to NIPS 2016, project page: http://www.iis.ee.ic.ac.uk/rkouskou/research/SRN.html
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we tackle the problem of estimating the 3D pose of object instances, using convolutional neural networks. State of the art methods usually solve the challenging problem of regression in angle space indirectly, focusing on learning discriminative features that are later fed into a separate architecture for 3D pose estimation. In contrast, we propose an end-to-end learning framework for directly regressing object poses by exploiting Siamese Networks. For a given image pair, we enforce a similarity measure between the representation of the sample images in the feature and pose space respectively, that is shown to boost regression performance. Furthermore, we argue that our pose-guided feature learning using our Siamese Regression Network generates more discriminative features that outperform the state of the art. Last, our feature learning formulation provides the ability of learning features that can perform under severe occlusions, demonstrating high performance on our novel hand-object dataset.
[ { "version": "v1", "created": "Fri, 8 Jul 2016 07:25:47 GMT" } ]
2016-07-11T00:00:00
[ [ "Doumanoglou", "Andreas", "" ], [ "Balntas", "Vassileios", "" ], [ "Kouskouridas", "Rigas", "" ], [ "Kim", "Tae-Kyun", "" ] ]
TITLE: Siamese Regression Networks with Efficient mid-level Feature Extraction for 3D Object Pose Estimation ABSTRACT: In this paper we tackle the problem of estimating the 3D pose of object instances, using convolutional neural networks. State of the art methods usually solve the challenging problem of regression in angle space indirectly, focusing on learning discriminative features that are later fed into a separate architecture for 3D pose estimation. In contrast, we propose an end-to-end learning framework for directly regressing object poses by exploiting Siamese Networks. For a given image pair, we enforce a similarity measure between the representation of the sample images in the feature and pose space respectively, that is shown to boost regression performance. Furthermore, we argue that our pose-guided feature learning using our Siamese Regression Network generates more discriminative features that outperform the state of the art. Last, our feature learning formulation provides the ability of learning features that can perform under severe occlusions, demonstrating high performance on our novel hand-object dataset.
1607.02329
Markus Wulfmeier
Markus Wulfmeier, Dominic Zeng Wang and Ingmar Posner
Watch This: Scalable Cost-Function Learning for Path Planning in Urban Environments
Accepted for publication in the Proceedings of the 2016 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS 2016)
null
null
null
cs.RO cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work, we present an approach to learn cost maps for driving in complex urban environments from a very large number of demonstrations of driving behaviour by human experts. The learned cost maps are constructed directly from raw sensor measurements, bypassing the effort of manually designing cost maps as well as features. When deploying the learned cost maps, the trajectories generated not only replicate human-like driving behaviour but are also demonstrably robust against systematic errors in putative robot configuration. To achieve this we deploy a Maximum Entropy based, non-linear IRL framework which uses Fully Convolutional Neural Networks (FCNs) to represent the cost model underlying expert driving behaviour. Using a deep, parametric approach enables us to scale efficiently to large datasets and complex behaviours by being run-time independent of dataset extent during deployment. We demonstrate the scalability and the performance of the proposed approach on an ambitious dataset collected over the course of one year including more than 25k demonstration trajectories extracted from over 120km of driving around pedestrianised areas in the city of Milton Keynes, UK. We evaluate the resulting cost representations by showing the advantages over a carefully manually designed cost map and, in addition, demonstrate its robustness to systematic errors by learning precise cost-maps even in the presence of system calibration perturbations.
[ { "version": "v1", "created": "Fri, 8 Jul 2016 11:59:51 GMT" } ]
2016-07-11T00:00:00
[ [ "Wulfmeier", "Markus", "" ], [ "Wang", "Dominic Zeng", "" ], [ "Posner", "Ingmar", "" ] ]
TITLE: Watch This: Scalable Cost-Function Learning for Path Planning in Urban Environments ABSTRACT: In this work, we present an approach to learn cost maps for driving in complex urban environments from a very large number of demonstrations of driving behaviour by human experts. The learned cost maps are constructed directly from raw sensor measurements, bypassing the effort of manually designing cost maps as well as features. When deploying the learned cost maps, the trajectories generated not only replicate human-like driving behaviour but are also demonstrably robust against systematic errors in putative robot configuration. To achieve this we deploy a Maximum Entropy based, non-linear IRL framework which uses Fully Convolutional Neural Networks (FCNs) to represent the cost model underlying expert driving behaviour. Using a deep, parametric approach enables us to scale efficiently to large datasets and complex behaviours by being run-time independent of dataset extent during deployment. We demonstrate the scalability and the performance of the proposed approach on an ambitious dataset collected over the course of one year including more than 25k demonstration trajectories extracted from over 120km of driving around pedestrianised areas in the city of Milton Keynes, UK. We evaluate the resulting cost representations by showing the advantages over a carefully manually designed cost map and, in addition, demonstrate its robustness to systematic errors by learning precise cost-maps even in the presence of system calibration perturbations.
1607.02383
Yoonchang Han
Yoonchang Han, Kyogu Lee
Acoustic scene classification using convolutional neural network and multiple-width frequency-delta data augmentation
11 pages, 5 figures, submitted to IEEE/ACM Transactions on Audio, Speech, and Language Processing on 08-July-2016
null
null
null
cs.SD
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In recent years, neural network approaches have shown superior performance to conventional hand-made features in numerous application areas. In particular, convolutional neural networks (ConvNets) exploit spatially local correlations across input data to improve the performance of audio processing tasks, such as speech recognition, musical chord recognition, and onset detection. Here we apply ConvNet to acoustic scene classification, and show that the error rate can be further decreased by using delta features in the frequency domain. We propose a multiple-width frequency-delta (MWFD) data augmentation method that uses static mel-spectrogram and frequency-delta features as individual input examples. In addition, we describe a ConvNet output aggregation method designed for MWFD augmentation, folded mean aggregation, which combines output probabilities of static and MWFD features from the same analysis window using multiplication first, rather than taking an average of all output probabilities. We describe calculation results using the DCASE 2016 challenge dataset, which shows that ConvNet outperforms both of the baseline system with hand-crafted features and a deep neural network approach by around 7%. The performance was further improved (by 5.7%) using the MWFD augmentation together with folded mean aggregation. The system exhibited a classification accuracy of 0.831 when classifying 15 acoustic scenes.
[ { "version": "v1", "created": "Fri, 8 Jul 2016 14:33:58 GMT" } ]
2016-07-11T00:00:00
[ [ "Han", "Yoonchang", "" ], [ "Lee", "Kyogu", "" ] ]
TITLE: Acoustic scene classification using convolutional neural network and multiple-width frequency-delta data augmentation ABSTRACT: In recent years, neural network approaches have shown superior performance to conventional hand-made features in numerous application areas. In particular, convolutional neural networks (ConvNets) exploit spatially local correlations across input data to improve the performance of audio processing tasks, such as speech recognition, musical chord recognition, and onset detection. Here we apply ConvNet to acoustic scene classification, and show that the error rate can be further decreased by using delta features in the frequency domain. We propose a multiple-width frequency-delta (MWFD) data augmentation method that uses static mel-spectrogram and frequency-delta features as individual input examples. In addition, we describe a ConvNet output aggregation method designed for MWFD augmentation, folded mean aggregation, which combines output probabilities of static and MWFD features from the same analysis window using multiplication first, rather than taking an average of all output probabilities. We describe calculation results using the DCASE 2016 challenge dataset, which shows that ConvNet outperforms both of the baseline system with hand-crafted features and a deep neural network approach by around 7%. The performance was further improved (by 5.7%) using the MWFD augmentation together with folded mean aggregation. The system exhibited a classification accuracy of 0.831 when classifying 15 acoustic scenes.
1607.02504
Xiao Yang
Xiao Yang, Roland Kwitt, Marc Niethammer
Fast Predictive Image Registration
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a method to predict image deformations based on patch-wise image appearance. Specifically, we design a patch-based deep encoder-decoder network which learns the pixel/voxel-wise mapping between image appearance and registration parameters. Our approach can predict general deformation parameterizations, however, we focus on the large deformation diffeomorphic metric mapping (LDDMM) registration model. By predicting the LDDMM momentum-parameterization we retain the desirable theoretical properties of LDDMM, while reducing computation time by orders of magnitude: combined with patch pruning, we achieve a 1500x/66x speed up compared to GPU-based optimization for 2D/3D image registration. Our approach has better prediction accuracy than predicting deformation or velocity fields and results in diffeomorphic transformations. Additionally, we create a Bayesian probabilistic version of our network, which allows evaluation of deformation field uncertainty through Monte Carlo sampling using dropout at test time. We show that deformation uncertainty highlights areas of ambiguous deformations. We test our method on the OASIS brain image dataset in 2D and 3D.
[ { "version": "v1", "created": "Fri, 8 Jul 2016 19:58:56 GMT" } ]
2016-07-11T00:00:00
[ [ "Yang", "Xiao", "" ], [ "Kwitt", "Roland", "" ], [ "Niethammer", "Marc", "" ] ]
TITLE: Fast Predictive Image Registration ABSTRACT: We present a method to predict image deformations based on patch-wise image appearance. Specifically, we design a patch-based deep encoder-decoder network which learns the pixel/voxel-wise mapping between image appearance and registration parameters. Our approach can predict general deformation parameterizations, however, we focus on the large deformation diffeomorphic metric mapping (LDDMM) registration model. By predicting the LDDMM momentum-parameterization we retain the desirable theoretical properties of LDDMM, while reducing computation time by orders of magnitude: combined with patch pruning, we achieve a 1500x/66x speed up compared to GPU-based optimization for 2D/3D image registration. Our approach has better prediction accuracy than predicting deformation or velocity fields and results in diffeomorphic transformations. Additionally, we create a Bayesian probabilistic version of our network, which allows evaluation of deformation field uncertainty through Monte Carlo sampling using dropout at test time. We show that deformation uncertainty highlights areas of ambiguous deformations. We test our method on the OASIS brain image dataset in 2D and 3D.
1406.2139
Conrad Sanderson
Masoud Faraki, Maziar Palhang, Conrad Sanderson
Log-Euclidean Bag of Words for Human Action Recognition
null
IET Computer Vision, Vol. 9, No. 3, 2015
10.1049/iet-cvi.2014.0018
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Representing videos by densely extracted local space-time features has recently become a popular approach for analysing actions. In this paper, we tackle the problem of categorising human actions by devising Bag of Words (BoW) models based on covariance matrices of spatio-temporal features, with the features formed from histograms of optical flow. Since covariance matrices form a special type of Riemannian manifold, the space of Symmetric Positive Definite (SPD) matrices, non-Euclidean geometry should be taken into account while discriminating between covariance matrices. To this end, we propose to embed SPD manifolds to Euclidean spaces via a diffeomorphism and extend the BoW approach to its Riemannian version. The proposed BoW approach takes into account the manifold geometry of SPD matrices during the generation of the codebook and histograms. Experiments on challenging human action datasets show that the proposed method obtains notable improvements in discrimination accuracy, in comparison to several state-of-the-art methods.
[ { "version": "v1", "created": "Mon, 9 Jun 2014 11:14:03 GMT" }, { "version": "v2", "created": "Tue, 8 Jul 2014 09:33:58 GMT" }, { "version": "v3", "created": "Thu, 7 Jul 2016 09:27:40 GMT" } ]
2016-07-08T00:00:00
[ [ "Faraki", "Masoud", "" ], [ "Palhang", "Maziar", "" ], [ "Sanderson", "Conrad", "" ] ]
TITLE: Log-Euclidean Bag of Words for Human Action Recognition ABSTRACT: Representing videos by densely extracted local space-time features has recently become a popular approach for analysing actions. In this paper, we tackle the problem of categorising human actions by devising Bag of Words (BoW) models based on covariance matrices of spatio-temporal features, with the features formed from histograms of optical flow. Since covariance matrices form a special type of Riemannian manifold, the space of Symmetric Positive Definite (SPD) matrices, non-Euclidean geometry should be taken into account while discriminating between covariance matrices. To this end, we propose to embed SPD manifolds to Euclidean spaces via a diffeomorphism and extend the BoW approach to its Riemannian version. The proposed BoW approach takes into account the manifold geometry of SPD matrices during the generation of the codebook and histograms. Experiments on challenging human action datasets show that the proposed method obtains notable improvements in discrimination accuracy, in comparison to several state-of-the-art methods.
1607.01794
Zhenyang Li
Zhenyang Li, Efstratios Gavves, Mihir Jain, Cees G. M. Snoek
VideoLSTM Convolves, Attends and Flows for Action Recognition
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a new architecture for end-to-end sequence learning of actions in video, we call VideoLSTM. Rather than adapting the video to the peculiarities of established recurrent or convolutional architectures, we adapt the architecture to fit the requirements of the video medium. Starting from the soft-Attention LSTM, VideoLSTM makes three novel contributions. First, video has a spatial layout. To exploit the spatial correlation we hardwire convolutions in the soft-Attention LSTM architecture. Second, motion not only informs us about the action content, but also guides better the attention towards the relevant spatio-temporal locations. We introduce motion-based attention. And finally, we demonstrate how the attention from VideoLSTM can be used for action localization by relying on just the action class label. Experiments and comparisons on challenging datasets for action classification and localization support our claims.
[ { "version": "v1", "created": "Wed, 6 Jul 2016 20:00:20 GMT" } ]
2016-07-08T00:00:00
[ [ "Li", "Zhenyang", "" ], [ "Gavves", "Efstratios", "" ], [ "Jain", "Mihir", "" ], [ "Snoek", "Cees G. M.", "" ] ]
TITLE: VideoLSTM Convolves, Attends and Flows for Action Recognition ABSTRACT: We present a new architecture for end-to-end sequence learning of actions in video, we call VideoLSTM. Rather than adapting the video to the peculiarities of established recurrent or convolutional architectures, we adapt the architecture to fit the requirements of the video medium. Starting from the soft-Attention LSTM, VideoLSTM makes three novel contributions. First, video has a spatial layout. To exploit the spatial correlation we hardwire convolutions in the soft-Attention LSTM architecture. Second, motion not only informs us about the action content, but also guides better the attention towards the relevant spatio-temporal locations. We introduce motion-based attention. And finally, we demonstrate how the attention from VideoLSTM can be used for action localization by relying on just the action class label. Experiments and comparisons on challenging datasets for action classification and localization support our claims.
1607.01977
Yuchao Dai Dr.
Xibin Song, Yuchao Dai, Xueying Qin
Deep Depth Super-Resolution : Learning Depth Super-Resolution using Deep Convolutional Neural Network
13 pages, 10 figures
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Depth image super-resolution is an extremely challenging task due to the information loss in sub-sampling. Deep convolutional neural network have been widely applied to color image super-resolution. Quite surprisingly, this success has not been matched to depth super-resolution. This is mainly due to the inherent difference between color and depth images. In this paper, we bridge up the gap and extend the success of deep convolutional neural network to depth super-resolution. The proposed deep depth super-resolution method learns the mapping from a low-resolution depth image to a high resolution one in an end-to-end style. Furthermore, to better regularize the learned depth map, we propose to exploit the depth field statistics and the local correlation between depth image and color image. These priors are integrated in an energy minimization formulation, where the deep neural network learns the unary term, the depth field statistics works as global model constraint and the color-depth correlation is utilized to enforce the local structure in depth images. Extensive experiments on various depth super-resolution benchmark datasets show that our method outperforms the state-of-the-art depth image super-resolution methods with a margin.
[ { "version": "v1", "created": "Thu, 7 Jul 2016 12:01:59 GMT" } ]
2016-07-08T00:00:00
[ [ "Song", "Xibin", "" ], [ "Dai", "Yuchao", "" ], [ "Qin", "Xueying", "" ] ]
TITLE: Deep Depth Super-Resolution : Learning Depth Super-Resolution using Deep Convolutional Neural Network ABSTRACT: Depth image super-resolution is an extremely challenging task due to the information loss in sub-sampling. Deep convolutional neural network have been widely applied to color image super-resolution. Quite surprisingly, this success has not been matched to depth super-resolution. This is mainly due to the inherent difference between color and depth images. In this paper, we bridge up the gap and extend the success of deep convolutional neural network to depth super-resolution. The proposed deep depth super-resolution method learns the mapping from a low-resolution depth image to a high resolution one in an end-to-end style. Furthermore, to better regularize the learned depth map, we propose to exploit the depth field statistics and the local correlation between depth image and color image. These priors are integrated in an energy minimization formulation, where the deep neural network learns the unary term, the depth field statistics works as global model constraint and the color-depth correlation is utilized to enforce the local structure in depth images. Extensive experiments on various depth super-resolution benchmark datasets show that our method outperforms the state-of-the-art depth image super-resolution methods with a margin.
1607.02003
Mihir Jain
Mihir Jain, Jan van Gemert, Herv\'e J\'egou, Patrick Bouthemy, Cees G.M. Snoek
Tubelets: Unsupervised action proposals from spatiotemporal super-voxels
submitted to International Journal of Computer Vision
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper considers the problem of localizing actions in videos as a sequences of bounding boxes. The objective is to generate action proposals that are likely to include the action of interest, ideally achieving high recall with few proposals. Our contributions are threefold. First, inspired by selective search for object proposals, we introduce an approach to generate action proposals from spatiotemporal super-voxels in an unsupervised manner, we call them Tubelets. Second, along with the static features from individual frames our approach advantageously exploits motion. We introduce independent motion evidence as a feature to characterize how the action deviates from the background and explicitly incorporate such motion information in various stages of the proposal generation. Finally, we introduce spatiotemporal refinement of Tubelets, for more precise localization of actions, and pruning to keep the number of Tubelets limited. We demonstrate the suitability of our approach by extensive experiments for action proposal quality and action localization on three public datasets: UCF Sports, MSR-II and UCF101. For action proposal quality, our unsupervised proposals beat all other existing approaches on the three datasets. For action localization, we show top performance on both the trimmed videos of UCF Sports and UCF101 as well as the untrimmed videos of MSR-II.
[ { "version": "v1", "created": "Thu, 7 Jul 2016 13:30:17 GMT" } ]
2016-07-08T00:00:00
[ [ "Jain", "Mihir", "" ], [ "van Gemert", "Jan", "" ], [ "Jégou", "Hervé", "" ], [ "Bouthemy", "Patrick", "" ], [ "Snoek", "Cees G. M.", "" ] ]
TITLE: Tubelets: Unsupervised action proposals from spatiotemporal super-voxels ABSTRACT: This paper considers the problem of localizing actions in videos as a sequences of bounding boxes. The objective is to generate action proposals that are likely to include the action of interest, ideally achieving high recall with few proposals. Our contributions are threefold. First, inspired by selective search for object proposals, we introduce an approach to generate action proposals from spatiotemporal super-voxels in an unsupervised manner, we call them Tubelets. Second, along with the static features from individual frames our approach advantageously exploits motion. We introduce independent motion evidence as a feature to characterize how the action deviates from the background and explicitly incorporate such motion information in various stages of the proposal generation. Finally, we introduce spatiotemporal refinement of Tubelets, for more precise localization of actions, and pruning to keep the number of Tubelets limited. We demonstrate the suitability of our approach by extensive experiments for action proposal quality and action localization on three public datasets: UCF Sports, MSR-II and UCF101. For action proposal quality, our unsupervised proposals beat all other existing approaches on the three datasets. For action localization, we show top performance on both the trimmed videos of UCF Sports and UCF101 as well as the untrimmed videos of MSR-II.
1607.02062
Georg Groh
Christoph Fuchs and Akash Nayyar and Ruth Nussbaumer and Georg Groh
Estimating the Dissemination of Social and Mobile Search in Categories of Information Needs Using Websites as Proxies
null
null
null
null
cs.CY cs.IR cs.SI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
With the increasing popularity of social means to satisfy information needs using Social Media (e.g., Social Media Question Asking, SMQA) or Social Information Retrieval approaches, this paper tries to identify types of information needs which are inherently social and therefore better suited for those techniques. We describe an experiment where prominent websites from various content categories are used to represent their respective content area and allow to correlate attributes of the content areas. The underlying assumption is that successful websites for focused content areas perfectly align with the information seekers' requirements when satisfying information needs in the respective content areas. Based on a manually collected dataset of URLs from websites covering a broad range of topics taken from Alexa (http://www.alexa.com} (retrieved 2015-11-04)) (a company that publishes statistics about web traffic), a crowdsourcing approach is employed to rate the information needs that could get solved by the respective URLs according to several dimensions (incl. sociality and mobility) to investigate possible correlations with other attributes. Our results suggest that information needs which do not require a certain formal expertise play an important role in social information retrieval and that some content areas are better suited for social information retrieval (e.g., Factual Knowledge & News, Games, Lifestyle) than others (e.g., Health & Lifestyle).
[ { "version": "v1", "created": "Thu, 7 Jul 2016 16:01:41 GMT" } ]
2016-07-08T00:00:00
[ [ "Fuchs", "Christoph", "" ], [ "Nayyar", "Akash", "" ], [ "Nussbaumer", "Ruth", "" ], [ "Groh", "Georg", "" ] ]
TITLE: Estimating the Dissemination of Social and Mobile Search in Categories of Information Needs Using Websites as Proxies ABSTRACT: With the increasing popularity of social means to satisfy information needs using Social Media (e.g., Social Media Question Asking, SMQA) or Social Information Retrieval approaches, this paper tries to identify types of information needs which are inherently social and therefore better suited for those techniques. We describe an experiment where prominent websites from various content categories are used to represent their respective content area and allow to correlate attributes of the content areas. The underlying assumption is that successful websites for focused content areas perfectly align with the information seekers' requirements when satisfying information needs in the respective content areas. Based on a manually collected dataset of URLs from websites covering a broad range of topics taken from Alexa (http://www.alexa.com} (retrieved 2015-11-04)) (a company that publishes statistics about web traffic), a crowdsourcing approach is employed to rate the information needs that could get solved by the respective URLs according to several dimensions (incl. sociality and mobility) to investigate possible correlations with other attributes. Our results suggest that information needs which do not require a certain formal expertise play an important role in social information retrieval and that some content areas are better suited for social information retrieval (e.g., Factual Knowledge & News, Games, Lifestyle) than others (e.g., Health & Lifestyle).
1607.01462
Yingfei Wang
Yingfei Wang and Warren Powell
An optimal learning method for developing personalized treatment regimes
null
null
null
null
stat.ML cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A treatment regime is a function that maps individual patient information to a recommended treatment, hence explicitly incorporating the heterogeneity in need for treatment across individuals. Patient responses are dichotomous and can be predicted through an unknown relationship that depends on the patient information and the selected treatment. The goal is to find the treatments that lead to the best patient responses on average. Each experiment is expensive, forcing us to learn the most from each experiment. We adopt a Bayesian approach both to incorporate possible prior information and to update our treatment regime continuously as information accrues, with the potential to allow smaller yet more informative trials and for patients to receive better treatment. By formulating the problem as contextual bandits, we introduce a knowledge gradient policy to guide the treatment assignment by maximizing the expected value of information, for which an approximation method is used to overcome computational challenges. We provide a detailed study on how to make sequential medical decisions under uncertainty to reduce health care costs on a real world knee replacement dataset. We use clustering and LASSO to deal with the intrinsic sparsity in health datasets. We show experimentally that even though the problem is sparse, through careful selection of physicians (versus picking them at random), we can significantly improve the success rates.
[ { "version": "v1", "created": "Wed, 6 Jul 2016 02:34:21 GMT" } ]
2016-07-07T00:00:00
[ [ "Wang", "Yingfei", "" ], [ "Powell", "Warren", "" ] ]
TITLE: An optimal learning method for developing personalized treatment regimes ABSTRACT: A treatment regime is a function that maps individual patient information to a recommended treatment, hence explicitly incorporating the heterogeneity in need for treatment across individuals. Patient responses are dichotomous and can be predicted through an unknown relationship that depends on the patient information and the selected treatment. The goal is to find the treatments that lead to the best patient responses on average. Each experiment is expensive, forcing us to learn the most from each experiment. We adopt a Bayesian approach both to incorporate possible prior information and to update our treatment regime continuously as information accrues, with the potential to allow smaller yet more informative trials and for patients to receive better treatment. By formulating the problem as contextual bandits, we introduce a knowledge gradient policy to guide the treatment assignment by maximizing the expected value of information, for which an approximation method is used to overcome computational challenges. We provide a detailed study on how to make sequential medical decisions under uncertainty to reduce health care costs on a real world knee replacement dataset. We use clustering and LASSO to deal with the intrinsic sparsity in health datasets. We show experimentally that even though the problem is sparse, through careful selection of physicians (versus picking them at random), we can significantly improve the success rates.
1607.01577
Le Dong
Le Dong, Ling He, Gaipeng Kong, Qianni Zhang, Xiaochun Cao, and Ebroul Izquierdo
CUNet: A Compact Unsupervised Network for Image Classification
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we propose a compact network called CUNet (compact unsupervised network) to counter the image classification challenge. Different from the traditional convolutional neural networks learning filters by the time-consuming stochastic gradient descent, CUNet learns the filter bank from diverse image patches with the simple K-means, which significantly avoids the requirement of scarce labeled training images, reduces the training consumption, and maintains the high discriminative ability. Besides, we propose a new pooling method named weighted pooling considering the different weight values of adjacent neurons, which helps to improve the robustness to small image distortions. In the output layer, CUNet integrates the feature maps gained in the last hidden layer, and straightforwardly computes histograms in non-overlapped blocks. To reduce feature redundancy, we implement the max-pooling operation on adjacent blocks to select the most competitive features. Comprehensive experiments are conducted to demonstrate the state-of-the-art classification performances with CUNet on CIFAR-10, STL-10, MNIST and Caltech101 benchmark datasets.
[ { "version": "v1", "created": "Wed, 6 Jul 2016 11:56:52 GMT" } ]
2016-07-07T00:00:00
[ [ "Dong", "Le", "" ], [ "He", "Ling", "" ], [ "Kong", "Gaipeng", "" ], [ "Zhang", "Qianni", "" ], [ "Cao", "Xiaochun", "" ], [ "Izquierdo", "Ebroul", "" ] ]
TITLE: CUNet: A Compact Unsupervised Network for Image Classification ABSTRACT: In this paper, we propose a compact network called CUNet (compact unsupervised network) to counter the image classification challenge. Different from the traditional convolutional neural networks learning filters by the time-consuming stochastic gradient descent, CUNet learns the filter bank from diverse image patches with the simple K-means, which significantly avoids the requirement of scarce labeled training images, reduces the training consumption, and maintains the high discriminative ability. Besides, we propose a new pooling method named weighted pooling considering the different weight values of adjacent neurons, which helps to improve the robustness to small image distortions. In the output layer, CUNet integrates the feature maps gained in the last hidden layer, and straightforwardly computes histograms in non-overlapped blocks. To reduce feature redundancy, we implement the max-pooling operation on adjacent blocks to select the most competitive features. Comprehensive experiments are conducted to demonstrate the state-of-the-art classification performances with CUNet on CIFAR-10, STL-10, MNIST and Caltech101 benchmark datasets.
1607.01582
Gerasimos Spanakis
Gerasimos Spanakis and Gerhard Weiss and Anne Roefs
Bagged Boosted Trees for Classification of Ecological Momentary Assessment Data
to be presented at ECAI2016
null
null
null
cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Ecological Momentary Assessment (EMA) data is organized in multiple levels (per-subject, per-day, etc.) and this particular structure should be taken into account in machine learning algorithms used in EMA like decision trees and its variants. We propose a new algorithm called BBT (standing for Bagged Boosted Trees) that is enhanced by a over/under sampling method and can provide better estimates for the conditional class probability function. Experimental results on a real-world dataset show that BBT can benefit EMA data classification and performance.
[ { "version": "v1", "created": "Wed, 6 Jul 2016 12:10:29 GMT" } ]
2016-07-07T00:00:00
[ [ "Spanakis", "Gerasimos", "" ], [ "Weiss", "Gerhard", "" ], [ "Roefs", "Anne", "" ] ]
TITLE: Bagged Boosted Trees for Classification of Ecological Momentary Assessment Data ABSTRACT: Ecological Momentary Assessment (EMA) data is organized in multiple levels (per-subject, per-day, etc.) and this particular structure should be taken into account in machine learning algorithms used in EMA like decision trees and its variants. We propose a new algorithm called BBT (standing for Bagged Boosted Trees) that is enhanced by a over/under sampling method and can provide better estimates for the conditional class probability function. Experimental results on a real-world dataset show that BBT can benefit EMA data classification and performance.
1607.01690
Cen Wan
Cen Wan and Alex A. Freitas
A New Hierarchical Redundancy Eliminated Tree Augmented Naive Bayes Classifier for Coping with Gene Ontology-based Features
International Conference on Machine Learning (ICML 2016) Computational Biology Workshop
null
null
null
cs.LG cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Tree Augmented Naive Bayes classifier is a type of probabilistic graphical model that can represent some feature dependencies. In this work, we propose a Hierarchical Redundancy Eliminated Tree Augmented Naive Bayes (HRE-TAN) algorithm, which considers removing the hierarchical redundancy during the classifier learning process, when coping with data containing hierarchically structured features. The experiments showed that HRE-TAN obtains significantly better predictive performance than the conventional Tree Augmented Naive Bayes classifier, and enhanced the robustness against imbalanced class distributions, in aging-related gene datasets with Gene Ontology terms used as features.
[ { "version": "v1", "created": "Wed, 6 Jul 2016 16:00:43 GMT" } ]
2016-07-07T00:00:00
[ [ "Wan", "Cen", "" ], [ "Freitas", "Alex A.", "" ] ]
TITLE: A New Hierarchical Redundancy Eliminated Tree Augmented Naive Bayes Classifier for Coping with Gene Ontology-based Features ABSTRACT: The Tree Augmented Naive Bayes classifier is a type of probabilistic graphical model that can represent some feature dependencies. In this work, we propose a Hierarchical Redundancy Eliminated Tree Augmented Naive Bayes (HRE-TAN) algorithm, which considers removing the hierarchical redundancy during the classifier learning process, when coping with data containing hierarchically structured features. The experiments showed that HRE-TAN obtains significantly better predictive performance than the conventional Tree Augmented Naive Bayes classifier, and enhanced the robustness against imbalanced class distributions, in aging-related gene datasets with Gene Ontology terms used as features.
1607.01719
Baochen Sun
Baochen Sun, Kate Saenko
Deep CORAL: Correlation Alignment for Deep Domain Adaptation
Extended Abstract
null
null
null
cs.CV cs.AI cs.LG cs.NE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Deep neural networks are able to learn powerful representations from large quantities of labeled input data, however they cannot always generalize well across changes in input distributions. Domain adaptation algorithms have been proposed to compensate for the degradation in performance due to domain shift. In this paper, we address the case when the target domain is unlabeled, requiring unsupervised adaptation. CORAL is a "frustratingly easy" unsupervised domain adaptation method that aligns the second-order statistics of the source and target distributions with a linear transformation. Here, we extend CORAL to learn a nonlinear transformation that aligns correlations of layer activations in deep neural networks (Deep CORAL). Experiments on standard benchmark datasets show state-of-the-art performance.
[ { "version": "v1", "created": "Wed, 6 Jul 2016 17:35:55 GMT" } ]
2016-07-07T00:00:00
[ [ "Sun", "Baochen", "" ], [ "Saenko", "Kate", "" ] ]
TITLE: Deep CORAL: Correlation Alignment for Deep Domain Adaptation ABSTRACT: Deep neural networks are able to learn powerful representations from large quantities of labeled input data, however they cannot always generalize well across changes in input distributions. Domain adaptation algorithms have been proposed to compensate for the degradation in performance due to domain shift. In this paper, we address the case when the target domain is unlabeled, requiring unsupervised adaptation. CORAL is a "frustratingly easy" unsupervised domain adaptation method that aligns the second-order statistics of the source and target distributions with a linear transformation. Here, we extend CORAL to learn a nonlinear transformation that aligns correlations of layer activations in deep neural networks (Deep CORAL). Experiments on standard benchmark datasets show state-of-the-art performance.
1511.04397
Ehsan Hosseini-Asl
Ehsan Hosseini-Asl, Angshuman Guha
Similarity-based Text Recognition by Deeply Supervised Siamese Network
Accepted for presenting at Future Technologies Conference - (FTC 2016) San Francisco, December 6-7, 2016
null
null
null
cs.CV cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we propose a new text recognition model based on measuring the visual similarity of text and predicting the content of unlabeled texts. First a Siamese convolutional network is trained with deep supervision on a labeled training dataset. This network projects texts into a similarity manifold. The Deeply Supervised Siamese network learns visual similarity of texts. Then a K-nearest neighbor classifier is used to predict unlabeled text based on similarity distance to labeled texts. The performance of the model is evaluated on three datasets of machine-print and hand-written text combined. We demonstrate that the model reduces the cost of human estimation by $50\%-85\%$. The error of the system is less than $0.5\%$. The proposed model outperform conventional Siamese network by finding visually-similar barely-readable and readable text, e.g. machine-printed, handwritten, due to deep supervision. The results also demonstrate that the predicted labels are sometimes better than human labels e.g. spelling correction.
[ { "version": "v1", "created": "Fri, 13 Nov 2015 18:46:01 GMT" }, { "version": "v2", "created": "Wed, 18 Nov 2015 20:59:10 GMT" }, { "version": "v3", "created": "Fri, 8 Jan 2016 00:37:29 GMT" }, { "version": "v4", "created": "Sun, 3 Jul 2016 16:38:35 GMT" }, { "version": "v5", "created": "Tue, 5 Jul 2016 01:21:08 GMT" } ]
2016-07-06T00:00:00
[ [ "Hosseini-Asl", "Ehsan", "" ], [ "Guha", "Angshuman", "" ] ]
TITLE: Similarity-based Text Recognition by Deeply Supervised Siamese Network ABSTRACT: In this paper, we propose a new text recognition model based on measuring the visual similarity of text and predicting the content of unlabeled texts. First a Siamese convolutional network is trained with deep supervision on a labeled training dataset. This network projects texts into a similarity manifold. The Deeply Supervised Siamese network learns visual similarity of texts. Then a K-nearest neighbor classifier is used to predict unlabeled text based on similarity distance to labeled texts. The performance of the model is evaluated on three datasets of machine-print and hand-written text combined. We demonstrate that the model reduces the cost of human estimation by $50\%-85\%$. The error of the system is less than $0.5\%$. The proposed model outperform conventional Siamese network by finding visually-similar barely-readable and readable text, e.g. machine-printed, handwritten, due to deep supervision. The results also demonstrate that the predicted labels are sometimes better than human labels e.g. spelling correction.
1603.05614
Qilian Yu
Qilian Yu, Easton Li Xu, Shuguang Cui
Streaming Algorithms for News and Scientific Literature Recommendation: Submodular Maximization with a d-Knapsack Constraint
11 pages, 5 figures
null
null
null
cs.LG cs.DS
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Submodular maximization problems belong to the family of combinatorial optimization problems and enjoy wide applications. In this paper, we focus on the problem of maximizing a monotone submodular function subject to a $d$-knapsack constraint, for which we propose a streaming algorithm that achieves a $\left(\frac{1}{1+2d}-\epsilon\right)$-approximation of the optimal value, while it only needs one single pass through the dataset without storing all the data in the memory. In our experiments, we extensively evaluate the effectiveness of our proposed algorithm via two applications: news recommendation and scientific literature recommendation. It is observed that the proposed streaming algorithm achieves both execution speedup and memory saving by several orders of magnitude, compared with existing approaches.
[ { "version": "v1", "created": "Thu, 17 Mar 2016 19:01:12 GMT" }, { "version": "v2", "created": "Mon, 4 Jul 2016 16:15:56 GMT" }, { "version": "v3", "created": "Tue, 5 Jul 2016 00:43:45 GMT" } ]
2016-07-06T00:00:00
[ [ "Yu", "Qilian", "" ], [ "Xu", "Easton Li", "" ], [ "Cui", "Shuguang", "" ] ]
TITLE: Streaming Algorithms for News and Scientific Literature Recommendation: Submodular Maximization with a d-Knapsack Constraint ABSTRACT: Submodular maximization problems belong to the family of combinatorial optimization problems and enjoy wide applications. In this paper, we focus on the problem of maximizing a monotone submodular function subject to a $d$-knapsack constraint, for which we propose a streaming algorithm that achieves a $\left(\frac{1}{1+2d}-\epsilon\right)$-approximation of the optimal value, while it only needs one single pass through the dataset without storing all the data in the memory. In our experiments, we extensively evaluate the effectiveness of our proposed algorithm via two applications: news recommendation and scientific literature recommendation. It is observed that the proposed streaming algorithm achieves both execution speedup and memory saving by several orders of magnitude, compared with existing approaches.
1604.07364
Sibasish Laha
Sibasish Laha, Francis P. Keenan, Gary J. Ferland, Catherine A. Ramsbottom, and Kanti M. Aggarwal
Ultraviolet emission lines of Si II in quasars --- investigating the "Si II disaster"
Accepted for publication in ApJ
null
10.3847/0004-637X/825/1/28
null
astro-ph.GA physics.atom-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The observed line intensity ratios of the Si II 1263 and 1307 \AA\ multiplets to that of Si II 1814\,\AA\ in the broad line region of quasars are both an order of magnitude larger than the theoretical values. This was first pointed out by Baldwin et al. (1996), who termed it the "Si II disaster", and it has remained unresolved. We investigate the problem in the light of newly-published atomic data for Si II. Specifically, we perform broad line region calculations using several different atomic datasets within the CLOUDY modeling code under optically thick quasar cloud conditions. In addition, we test for selective pumping by the source photons or intrinsic galactic reddening as possible causes for the discrepancy, and also consider blending with other species. However, we find that none of the options investigated resolves the Si II disaster, with the potential exception of microturbulent velocity broadening and line blending. We find that a larger microturbulent velocity ($\sim 500 \rm \, kms^{-1}$) may solve the Si II disaster through continuum pumping and other effects. The CLOUDY models indicate strong blending of the Si II 1307 \AA\ multiplet with emission lines of O I, although the predicted degree of blending is incompatible with the observed 1263/1307 intensity ratios. Clearly, more work is required on the quasar modelling of not just the Si II lines but also nearby transitions (in particular those of O I) to fully investigate if blending may be responsible for the Si II disaster.
[ { "version": "v1", "created": "Mon, 25 Apr 2016 19:01:58 GMT" } ]
2016-07-06T00:00:00
[ [ "Laha", "Sibasish", "" ], [ "Keenan", "Francis P.", "" ], [ "Ferland", "Gary J.", "" ], [ "Ramsbottom", "Catherine A.", "" ], [ "Aggarwal", "Kanti M.", "" ] ]
TITLE: Ultraviolet emission lines of Si II in quasars --- investigating the "Si II disaster" ABSTRACT: The observed line intensity ratios of the Si II 1263 and 1307 \AA\ multiplets to that of Si II 1814\,\AA\ in the broad line region of quasars are both an order of magnitude larger than the theoretical values. This was first pointed out by Baldwin et al. (1996), who termed it the "Si II disaster", and it has remained unresolved. We investigate the problem in the light of newly-published atomic data for Si II. Specifically, we perform broad line region calculations using several different atomic datasets within the CLOUDY modeling code under optically thick quasar cloud conditions. In addition, we test for selective pumping by the source photons or intrinsic galactic reddening as possible causes for the discrepancy, and also consider blending with other species. However, we find that none of the options investigated resolves the Si II disaster, with the potential exception of microturbulent velocity broadening and line blending. We find that a larger microturbulent velocity ($\sim 500 \rm \, kms^{-1}$) may solve the Si II disaster through continuum pumping and other effects. The CLOUDY models indicate strong blending of the Si II 1307 \AA\ multiplet with emission lines of O I, although the predicted degree of blending is incompatible with the observed 1263/1307 intensity ratios. Clearly, more work is required on the quasar modelling of not just the Si II lines but also nearby transitions (in particular those of O I) to fully investigate if blending may be responsible for the Si II disaster.
1606.09002
Cong Yao
Cong Yao, Xiang Bai, Nong Sang, Xinyu Zhou, Shuchang Zhou and Zhimin Cao
Scene Text Detection via Holistic, Multi-Channel Prediction
10 pages, 9 figures, 5 tables
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recently, scene text detection has become an active research topic in computer vision and document analysis, because of its great importance and significant challenge. However, vast majority of the existing methods detect text within local regions, typically through extracting character, word or line level candidates followed by candidate aggregation and false positive elimination, which potentially exclude the effect of wide-scope and long-range contextual cues in the scene. To take full advantage of the rich information available in the whole natural image, we propose to localize text in a holistic manner, by casting scene text detection as a semantic segmentation problem. The proposed algorithm directly runs on full images and produces global, pixel-wise prediction maps, in which detections are subsequently formed. To better make use of the properties of text, three types of information regarding text region, individual characters and their relationship are estimated, with a single Fully Convolutional Network (FCN) model. With such predictions of text properties, the proposed algorithm can simultaneously handle horizontal, multi-oriented and curved text in real-world natural images. The experiments on standard benchmarks, including ICDAR 2013, ICDAR 2015 and MSRA-TD500, demonstrate that the proposed algorithm substantially outperforms previous state-of-the-art approaches. Moreover, we report the first baseline result on the recently-released, large-scale dataset COCO-Text.
[ { "version": "v1", "created": "Wed, 29 Jun 2016 08:45:17 GMT" }, { "version": "v2", "created": "Tue, 5 Jul 2016 11:22:49 GMT" } ]
2016-07-06T00:00:00
[ [ "Yao", "Cong", "" ], [ "Bai", "Xiang", "" ], [ "Sang", "Nong", "" ], [ "Zhou", "Xinyu", "" ], [ "Zhou", "Shuchang", "" ], [ "Cao", "Zhimin", "" ] ]
TITLE: Scene Text Detection via Holistic, Multi-Channel Prediction ABSTRACT: Recently, scene text detection has become an active research topic in computer vision and document analysis, because of its great importance and significant challenge. However, vast majority of the existing methods detect text within local regions, typically through extracting character, word or line level candidates followed by candidate aggregation and false positive elimination, which potentially exclude the effect of wide-scope and long-range contextual cues in the scene. To take full advantage of the rich information available in the whole natural image, we propose to localize text in a holistic manner, by casting scene text detection as a semantic segmentation problem. The proposed algorithm directly runs on full images and produces global, pixel-wise prediction maps, in which detections are subsequently formed. To better make use of the properties of text, three types of information regarding text region, individual characters and their relationship are estimated, with a single Fully Convolutional Network (FCN) model. With such predictions of text properties, the proposed algorithm can simultaneously handle horizontal, multi-oriented and curved text in real-world natural images. The experiments on standard benchmarks, including ICDAR 2013, ICDAR 2015 and MSRA-TD500, demonstrate that the proposed algorithm substantially outperforms previous state-of-the-art approaches. Moreover, we report the first baseline result on the recently-released, large-scale dataset COCO-Text.
1607.01115
Suyog Jain
Suyog Dutt Jain, Kristen Grauman
Click Carving: Segmenting Objects in Video with Point Clicks
A preliminary version of the material in this document was filed as University of Texas technical report no. UT AI16-01
null
null
University of Texas Technical Report UT AI16-01
cs.CV cs.AI cs.HC
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a novel form of interactive video object segmentation where a few clicks by the user helps the system produce a full spatio-temporal segmentation of the object of interest. Whereas conventional interactive pipelines take the user's initialization as a starting point, we show the value in the system taking the lead even in initialization. In particular, for a given video frame, the system precomputes a ranked list of thousands of possible segmentation hypotheses (also referred to as object region proposals) using image and motion cues. Then, the user looks at the top ranked proposals, and clicks on the object boundary to carve away erroneous ones. This process iterates (typically 2-3 times), and each time the system revises the top ranked proposal set, until the user is satisfied with a resulting segmentation mask. Finally, the mask is propagated across the video to produce a spatio-temporal object tube. On three challenging datasets, we provide extensive comparisons with both existing work and simpler alternative methods. In all, the proposed Click Carving approach strikes an excellent balance of accuracy and human effort. It outperforms all similarly fast methods, and is competitive or better than those requiring 2 to 12 times the effort.
[ { "version": "v1", "created": "Tue, 5 Jul 2016 05:35:22 GMT" } ]
2016-07-06T00:00:00
[ [ "Jain", "Suyog Dutt", "" ], [ "Grauman", "Kristen", "" ] ]
TITLE: Click Carving: Segmenting Objects in Video with Point Clicks ABSTRACT: We present a novel form of interactive video object segmentation where a few clicks by the user helps the system produce a full spatio-temporal segmentation of the object of interest. Whereas conventional interactive pipelines take the user's initialization as a starting point, we show the value in the system taking the lead even in initialization. In particular, for a given video frame, the system precomputes a ranked list of thousands of possible segmentation hypotheses (also referred to as object region proposals) using image and motion cues. Then, the user looks at the top ranked proposals, and clicks on the object boundary to carve away erroneous ones. This process iterates (typically 2-3 times), and each time the system revises the top ranked proposal set, until the user is satisfied with a resulting segmentation mask. Finally, the mask is propagated across the video to produce a spatio-temporal object tube. On three challenging datasets, we provide extensive comparisons with both existing work and simpler alternative methods. In all, the proposed Click Carving approach strikes an excellent balance of accuracy and human effort. It outperforms all similarly fast methods, and is competitive or better than those requiring 2 to 12 times the effort.
1607.01152
Nicolas Goix
Nicolas Goix (LTCI)
How to Evaluate the Quality of Unsupervised Anomaly Detection Algorithms?
null
null
null
null
stat.ML cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
When sufficient labeled data are available, classical criteria based on Receiver Operating Characteristic (ROC) or Precision-Recall (PR) curves can be used to compare the performance of un-supervised anomaly detection algorithms. However , in many situations, few or no data are labeled. This calls for alternative criteria one can compute on non-labeled data. In this paper, two criteria that do not require labels are empirically shown to discriminate accurately (w.r.t. ROC or PR based criteria) between algorithms. These criteria are based on existing Excess-Mass (EM) and Mass-Volume (MV) curves, which generally cannot be well estimated in large dimension. A methodology based on feature sub-sampling and aggregating is also described and tested, extending the use of these criteria to high-dimensional datasets and solving major drawbacks inherent to standard EM and MV curves.
[ { "version": "v1", "created": "Tue, 5 Jul 2016 08:58:44 GMT" } ]
2016-07-06T00:00:00
[ [ "Goix", "Nicolas", "", "LTCI" ] ]
TITLE: How to Evaluate the Quality of Unsupervised Anomaly Detection Algorithms? ABSTRACT: When sufficient labeled data are available, classical criteria based on Receiver Operating Characteristic (ROC) or Precision-Recall (PR) curves can be used to compare the performance of un-supervised anomaly detection algorithms. However , in many situations, few or no data are labeled. This calls for alternative criteria one can compute on non-labeled data. In this paper, two criteria that do not require labels are empirically shown to discriminate accurately (w.r.t. ROC or PR based criteria) between algorithms. These criteria are based on existing Excess-Mass (EM) and Mass-Volume (MV) curves, which generally cannot be well estimated in large dimension. A methodology based on feature sub-sampling and aggregating is also described and tested, extending the use of these criteria to high-dimensional datasets and solving major drawbacks inherent to standard EM and MV curves.
1605.04797
Qingnan Zhou
Qingnan Zhou, Alec Jacobson
Thingi10K: A Dataset of 10,000 3D-Printing Models
null
null
null
null
cs.GR
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Empirically validating new 3D-printing related algorithms and implementations requires testing data representative of inputs encountered \emph{in the wild}. An ideal benchmarking dataset should not only draw from the same distribution of shapes people print in terms of class (e.g., toys, mechanisms, jewelry), representation type (e.g., triangle soup meshes) and complexity (e.g., number of facets), but should also capture problems and artifacts endemic to 3D printing models (e.g., self-intersections, non-manifoldness). We observe that the contextual and geometric characteristics of 3D printing models differ significantly from those used for computer graphics applications, not to mention standard models (e.g., Stanford bunny, Armadillo, Fertility). We present a new dataset of 10,000 models collected from an online 3D printing model-sharing database. Via analysis of both geometric (e.g., triangle aspect ratios, manifoldness) and contextual (e.g., licenses, tags, classes) characteristics, we demonstrate that this dataset represents a more concise summary of real-world models used for 3D printing compared to existing datasets. To facilitate future research endeavors, we also present an online query interface to select subsets of the dataset according to project-specific characteristics. The complete dataset and per-model statistical data are freely available to the public.
[ { "version": "v1", "created": "Mon, 16 May 2016 15:09:19 GMT" }, { "version": "v2", "created": "Sat, 2 Jul 2016 03:15:10 GMT" } ]
2016-07-05T00:00:00
[ [ "Zhou", "Qingnan", "" ], [ "Jacobson", "Alec", "" ] ]
TITLE: Thingi10K: A Dataset of 10,000 3D-Printing Models ABSTRACT: Empirically validating new 3D-printing related algorithms and implementations requires testing data representative of inputs encountered \emph{in the wild}. An ideal benchmarking dataset should not only draw from the same distribution of shapes people print in terms of class (e.g., toys, mechanisms, jewelry), representation type (e.g., triangle soup meshes) and complexity (e.g., number of facets), but should also capture problems and artifacts endemic to 3D printing models (e.g., self-intersections, non-manifoldness). We observe that the contextual and geometric characteristics of 3D printing models differ significantly from those used for computer graphics applications, not to mention standard models (e.g., Stanford bunny, Armadillo, Fertility). We present a new dataset of 10,000 models collected from an online 3D printing model-sharing database. Via analysis of both geometric (e.g., triangle aspect ratios, manifoldness) and contextual (e.g., licenses, tags, classes) characteristics, we demonstrate that this dataset represents a more concise summary of real-world models used for 3D printing compared to existing datasets. To facilitate future research endeavors, we also present an online query interface to select subsets of the dataset according to project-specific characteristics. The complete dataset and per-model statistical data are freely available to the public.
1606.01994
Zihang Dai
Zihang Dai, Lei Li, Wei Xu
CFO: Conditional Focused Neural Question Answering with Large-scale Knowledge Bases
Accepted by ACL 2016
null
null
null
cs.CL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
How can we enable computers to automatically answer questions like "Who created the character Harry Potter"? Carefully built knowledge bases provide rich sources of facts. However, it remains a challenge to answer factoid questions raised in natural language due to numerous expressions of one question. In particular, we focus on the most common questions --- ones that can be answered with a single fact in the knowledge base. We propose CFO, a Conditional Focused neural-network-based approach to answering factoid questions with knowledge bases. Our approach first zooms in a question to find more probable candidate subject mentions, and infers the final answers with a unified conditional probabilistic framework. Powered by deep recurrent neural networks and neural embeddings, our proposed CFO achieves an accuracy of 75.7% on a dataset of 108k questions - the largest public one to date. It outperforms the current state of the art by an absolute margin of 11.8%.
[ { "version": "v1", "created": "Tue, 7 Jun 2016 01:36:07 GMT" }, { "version": "v2", "created": "Mon, 4 Jul 2016 03:04:38 GMT" } ]
2016-07-05T00:00:00
[ [ "Dai", "Zihang", "" ], [ "Li", "Lei", "" ], [ "Xu", "Wei", "" ] ]
TITLE: CFO: Conditional Focused Neural Question Answering with Large-scale Knowledge Bases ABSTRACT: How can we enable computers to automatically answer questions like "Who created the character Harry Potter"? Carefully built knowledge bases provide rich sources of facts. However, it remains a challenge to answer factoid questions raised in natural language due to numerous expressions of one question. In particular, we focus on the most common questions --- ones that can be answered with a single fact in the knowledge base. We propose CFO, a Conditional Focused neural-network-based approach to answering factoid questions with knowledge bases. Our approach first zooms in a question to find more probable candidate subject mentions, and infers the final answers with a unified conditional probabilistic framework. Powered by deep recurrent neural networks and neural embeddings, our proposed CFO achieves an accuracy of 75.7% on a dataset of 108k questions - the largest public one to date. It outperforms the current state of the art by an absolute margin of 11.8%.
1606.08998
Ernest C. H. Cheung
Ernest Cheung, Tsan Kwong Wong, Aniket Bera, Xiaogang Wang, and Dinesh Manocha
LCrowdV: Generating Labeled Videos for Simulation-based Crowd Behavior Learning
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a novel procedural framework to generate an arbitrary number of labeled crowd videos (LCrowdV). The resulting crowd video datasets are used to design accurate algorithms or training models for crowded scene understanding. Our overall approach is composed of two components: a procedural simulation framework for generating crowd movements and behaviors, and a procedural rendering framework to generate different videos or images. Each video or image is automatically labeled based on the environment, number of pedestrians, density, behavior, flow, lighting conditions, viewpoint, noise, etc. Furthermore, we can increase the realism by combining synthetically-generated behaviors with real-world background videos. We demonstrate the benefits of LCrowdV over prior lableled crowd datasets by improving the accuracy of pedestrian detection and crowd behavior classification algorithms. LCrowdV would be released on the WWW.
[ { "version": "v1", "created": "Wed, 29 Jun 2016 08:30:44 GMT" }, { "version": "v2", "created": "Mon, 4 Jul 2016 05:33:48 GMT" } ]
2016-07-05T00:00:00
[ [ "Cheung", "Ernest", "" ], [ "Wong", "Tsan Kwong", "" ], [ "Bera", "Aniket", "" ], [ "Wang", "Xiaogang", "" ], [ "Manocha", "Dinesh", "" ] ]
TITLE: LCrowdV: Generating Labeled Videos for Simulation-based Crowd Behavior Learning ABSTRACT: We present a novel procedural framework to generate an arbitrary number of labeled crowd videos (LCrowdV). The resulting crowd video datasets are used to design accurate algorithms or training models for crowded scene understanding. Our overall approach is composed of two components: a procedural simulation framework for generating crowd movements and behaviors, and a procedural rendering framework to generate different videos or images. Each video or image is automatically labeled based on the environment, number of pedestrians, density, behavior, flow, lighting conditions, viewpoint, noise, etc. Furthermore, we can increase the realism by combining synthetically-generated behaviors with real-world background videos. We demonstrate the benefits of LCrowdV over prior lableled crowd datasets by improving the accuracy of pedestrian detection and crowd behavior classification algorithms. LCrowdV would be released on the WWW.
1606.09446
Han Xiao
Han Xiao, Polina Rozenshtein, and Aristides Gionis
Discovering topically- and temporally-coherent events in interaction networks
null
null
null
null
cs.SI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
With the increasing use of online communication platforms, such as email, twitter, and messaging applications, we are faced with a growing amount of data that combine content (what is said), time (when), and user (by whom) information. An important computational challenge is to analyze these data, discover meaningful patterns, and understand what is happening. We consider the problem of mining online communication data and finding top-k temporal events. We define a temporal event to be a coherent topic that is discussed frequently, in a relatively short time span, while the information ow of the event respects the underlying network structure. We construct our model for detecting temporal events in two steps. We first introduce the notion of interaction meta-graph, which connects associated interactions. Using this notion, we define a temporal event to be a subset of interactions that (i) are topically and temporally close and (ii) correspond to a tree that captures the information ow. Finding the best temporal event leads to budget version of the prize-collecting Steiner-tree (PCST) problem, which we solve using three different methods: a greedy approach, a dynamic-programming algorithm, and an adaptation to an existing approximation algorithm. The problem of finding the top- k events among a set of candidate events maps to maximum set-cover problem, and thus, solved by greedy. We compare and analyze our algorithms in both synthetic and real datasets, such as twitter and email communication. The results show that our methods are able to detect meaningful temporal events.
[ { "version": "v1", "created": "Thu, 30 Jun 2016 12:08:06 GMT" }, { "version": "v2", "created": "Sun, 3 Jul 2016 17:30:26 GMT" } ]
2016-07-05T00:00:00
[ [ "Xiao", "Han", "" ], [ "Rozenshtein", "Polina", "" ], [ "Gionis", "Aristides", "" ] ]
TITLE: Discovering topically- and temporally-coherent events in interaction networks ABSTRACT: With the increasing use of online communication platforms, such as email, twitter, and messaging applications, we are faced with a growing amount of data that combine content (what is said), time (when), and user (by whom) information. An important computational challenge is to analyze these data, discover meaningful patterns, and understand what is happening. We consider the problem of mining online communication data and finding top-k temporal events. We define a temporal event to be a coherent topic that is discussed frequently, in a relatively short time span, while the information ow of the event respects the underlying network structure. We construct our model for detecting temporal events in two steps. We first introduce the notion of interaction meta-graph, which connects associated interactions. Using this notion, we define a temporal event to be a subset of interactions that (i) are topically and temporally close and (ii) correspond to a tree that captures the information ow. Finding the best temporal event leads to budget version of the prize-collecting Steiner-tree (PCST) problem, which we solve using three different methods: a greedy approach, a dynamic-programming algorithm, and an adaptation to an existing approximation algorithm. The problem of finding the top- k events among a set of candidate events maps to maximum set-cover problem, and thus, solved by greedy. We compare and analyze our algorithms in both synthetic and real datasets, such as twitter and email communication. The results show that our methods are able to detect meaningful temporal events.
1607.00410
Yusuke Watanabe Dr.
Yusuke Watanabe, Kazuma Hashimoto, Yoshimasa Tsuruoka
Domain Adaptation for Neural Networks by Parameter Augmentation
9 page. To appear in the first ACL Workshop on Representation Learning for NLP
null
null
null
cs.CL cs.AI cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a simple domain adaptation method for neural networks in a supervised setting. Supervised domain adaptation is a way of improving the generalization performance on the target domain by using the source domain dataset, assuming that both of the datasets are labeled. Recently, recurrent neural networks have been shown to be successful on a variety of NLP tasks such as caption generation; however, the existing domain adaptation techniques are limited to (1) tune the model parameters by the target dataset after the training by the source dataset, or (2) design the network to have dual output, one for the source domain and the other for the target domain. Reformulating the idea of the domain adaptation technique proposed by Daume (2007), we propose a simple domain adaptation method, which can be applied to neural networks trained with a cross-entropy loss. On captioning datasets, we show performance improvements over other domain adaptation methods.
[ { "version": "v1", "created": "Fri, 1 Jul 2016 21:24:21 GMT" } ]
2016-07-05T00:00:00
[ [ "Watanabe", "Yusuke", "" ], [ "Hashimoto", "Kazuma", "" ], [ "Tsuruoka", "Yoshimasa", "" ] ]
TITLE: Domain Adaptation for Neural Networks by Parameter Augmentation ABSTRACT: We propose a simple domain adaptation method for neural networks in a supervised setting. Supervised domain adaptation is a way of improving the generalization performance on the target domain by using the source domain dataset, assuming that both of the datasets are labeled. Recently, recurrent neural networks have been shown to be successful on a variety of NLP tasks such as caption generation; however, the existing domain adaptation techniques are limited to (1) tune the model parameters by the target dataset after the training by the source dataset, or (2) design the network to have dual output, one for the source domain and the other for the target domain. Reformulating the idea of the domain adaptation technique proposed by Daume (2007), we propose a simple domain adaptation method, which can be applied to neural networks trained with a cross-entropy loss. On captioning datasets, we show performance improvements over other domain adaptation methods.
1607.00417
Abir Das
Abir Das, Rameswar Panda and Amit K. Roy-Chowdhury
Continuous Adaptation of Multi-Camera Person Identification Models through Sparse Non-redundant Representative Selection
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The problem of image-base person identification/recognition is to provide an identity to the image of an individual based on learned models that describe his/her appearance. Most traditional person identification systems rely on learning a static model on tediously labeled training data. Though labeling manually is an indispensable part of a supervised framework, for a large scale identification system labeling huge amount of data is a significant overhead. For large multi-sensor data as typically encountered in camera networks, labeling a lot of samples does not always mean more information, as redundant images are labeled several times. In this work, we propose a convex optimization based iterative framework that progressively and judiciously chooses a sparse but informative set of samples for labeling, with minimal overlap with previously labeled images. We also use a structure preserving sparse reconstruction based classifier to reduce the training burden typically seen in discriminative classifiers. The two stage approach leads to a novel framework for online update of the classifiers involving only the incorporation of new labeled data rather than any expensive training phase. We demonstrate the effectiveness of our approach on multi-camera person re-identification datasets, to demonstrate the feasibility of learning online classification models in multi-camera big data applications. Using three benchmark datasets, we validate our approach and demonstrate that our framework achieves superior performance with significantly less amount of manual labeling.
[ { "version": "v1", "created": "Fri, 1 Jul 2016 21:48:16 GMT" } ]
2016-07-05T00:00:00
[ [ "Das", "Abir", "" ], [ "Panda", "Rameswar", "" ], [ "Roy-Chowdhury", "Amit K.", "" ] ]
TITLE: Continuous Adaptation of Multi-Camera Person Identification Models through Sparse Non-redundant Representative Selection ABSTRACT: The problem of image-base person identification/recognition is to provide an identity to the image of an individual based on learned models that describe his/her appearance. Most traditional person identification systems rely on learning a static model on tediously labeled training data. Though labeling manually is an indispensable part of a supervised framework, for a large scale identification system labeling huge amount of data is a significant overhead. For large multi-sensor data as typically encountered in camera networks, labeling a lot of samples does not always mean more information, as redundant images are labeled several times. In this work, we propose a convex optimization based iterative framework that progressively and judiciously chooses a sparse but informative set of samples for labeling, with minimal overlap with previously labeled images. We also use a structure preserving sparse reconstruction based classifier to reduce the training burden typically seen in discriminative classifiers. The two stage approach leads to a novel framework for online update of the classifiers involving only the incorporation of new labeled data rather than any expensive training phase. We demonstrate the effectiveness of our approach on multi-camera person re-identification datasets, to demonstrate the feasibility of learning online classification models in multi-camera big data applications. Using three benchmark datasets, we validate our approach and demonstrate that our framework achieves superior performance with significantly less amount of manual labeling.
1607.00442
Yongqiang Huang
Yongqiang Huang and Yu Sun
Datasets on object manipulation and interaction: a survey
8 pages, 3 figures, 3 tables
null
null
null
cs.RO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A dataset is crucial for model learning and evaluation. Choosing the right dataset to use or making a new dataset requires the knowledge of those that are available. In this work, we provide that knowledge, by reviewing twenty datasets that were published in the recent six years and that are directly related to object manipulation. We report on modalities, activities, and annotations for each individual dataset and give our view on its use for object manipulation. We also compare the datasets and summarize them. We conclude with our suggestion on future datasets.
[ { "version": "v1", "created": "Sat, 2 Jul 2016 00:58:57 GMT" } ]
2016-07-05T00:00:00
[ [ "Huang", "Yongqiang", "" ], [ "Sun", "Yu", "" ] ]
TITLE: Datasets on object manipulation and interaction: a survey ABSTRACT: A dataset is crucial for model learning and evaluation. Choosing the right dataset to use or making a new dataset requires the knowledge of those that are available. In this work, we provide that knowledge, by reviewing twenty datasets that were published in the recent six years and that are directly related to object manipulation. We report on modalities, activities, and annotations for each individual dataset and give our view on its use for object manipulation. We also compare the datasets and summarize them. We conclude with our suggestion on future datasets.
1607.00464
Le Dong
Le Dong, Xiuyuan Chen, Mengdie Mao, Qianni Zhang
NIST: An Image Classification Network to Image Semantic Retrieval
4 pages
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper proposes a classification network to image semantic retrieval (NIST) framework to counter the image retrieval challenge. Our approach leverages the successful classification network GoogleNet based on Convolutional Neural Networks to obtain the semantic feature matrix which contains the serial number of classes and corresponding probabilities. Compared with traditional image retrieval using feature matching to compute the similarity between two images, NIST leverages the semantic information to construct semantic feature matrix and uses the semantic distance algorithm to compute the similarity. Besides, the fusion strategy can significantly reduce storage and time consumption due to less classes participating in the last semantic distance computation. Experiments demonstrate that our NIST framework produces state-of-the-art results in retrieval experiments on MIRFLICKR-25K dataset.
[ { "version": "v1", "created": "Sat, 2 Jul 2016 04:39:24 GMT" } ]
2016-07-05T00:00:00
[ [ "Dong", "Le", "" ], [ "Chen", "Xiuyuan", "" ], [ "Mao", "Mengdie", "" ], [ "Zhang", "Qianni", "" ] ]
TITLE: NIST: An Image Classification Network to Image Semantic Retrieval ABSTRACT: This paper proposes a classification network to image semantic retrieval (NIST) framework to counter the image retrieval challenge. Our approach leverages the successful classification network GoogleNet based on Convolutional Neural Networks to obtain the semantic feature matrix which contains the serial number of classes and corresponding probabilities. Compared with traditional image retrieval using feature matching to compute the similarity between two images, NIST leverages the semantic information to construct semantic feature matrix and uses the semantic distance algorithm to compute the similarity. Besides, the fusion strategy can significantly reduce storage and time consumption due to less classes participating in the last semantic distance computation. Experiments demonstrate that our NIST framework produces state-of-the-art results in retrieval experiments on MIRFLICKR-25K dataset.
1607.00501
Le Dong
Le Dong, Na Lv, Qianni Zhang, Shanshan Xie, Ling He, Mengdie Mao
A Distributed Deep Representation Learning Model for Big Image Data Classification
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper describes an effective and efficient image classification framework nominated distributed deep representation learning model (DDRL). The aim is to strike the balance between the computational intensive deep learning approaches (tuned parameters) which are intended for distributed computing, and the approaches that focused on the designed parameters but often limited by sequential computing and cannot scale up. In the evaluation of our approach, it is shown that DDRL is able to achieve state-of-art classification accuracy efficiently on both medium and large datasets. The result implies that our approach is more efficient than the conventional deep learning approaches, and can be applied to big data that is too complex for parameter designing focused approaches. More specifically, DDRL contains two main components, i.e., feature extraction and selection. A hierarchical distributed deep representation learning algorithm is designed to extract image statistics and a nonlinear mapping algorithm is used to map the inherent statistics into abstract features. Both algorithms are carefully designed to avoid millions of parameters tuning. This leads to a more compact solution for image classification of big data. We note that the proposed approach is designed to be friendly with parallel computing. It is generic and easy to be deployed to different distributed computing resources. In the experiments, the largescale image datasets are classified with a DDRM implementation on Hadoop MapReduce, which shows high scalability and resilience.
[ { "version": "v1", "created": "Sat, 2 Jul 2016 12:33:12 GMT" } ]
2016-07-05T00:00:00
[ [ "Dong", "Le", "" ], [ "Lv", "Na", "" ], [ "Zhang", "Qianni", "" ], [ "Xie", "Shanshan", "" ], [ "He", "Ling", "" ], [ "Mao", "Mengdie", "" ] ]
TITLE: A Distributed Deep Representation Learning Model for Big Image Data Classification ABSTRACT: This paper describes an effective and efficient image classification framework nominated distributed deep representation learning model (DDRL). The aim is to strike the balance between the computational intensive deep learning approaches (tuned parameters) which are intended for distributed computing, and the approaches that focused on the designed parameters but often limited by sequential computing and cannot scale up. In the evaluation of our approach, it is shown that DDRL is able to achieve state-of-art classification accuracy efficiently on both medium and large datasets. The result implies that our approach is more efficient than the conventional deep learning approaches, and can be applied to big data that is too complex for parameter designing focused approaches. More specifically, DDRL contains two main components, i.e., feature extraction and selection. A hierarchical distributed deep representation learning algorithm is designed to extract image statistics and a nonlinear mapping algorithm is used to map the inherent statistics into abstract features. Both algorithms are carefully designed to avoid millions of parameters tuning. This leads to a more compact solution for image classification of big data. We note that the proposed approach is designed to be friendly with parallel computing. It is generic and easy to be deployed to different distributed computing resources. In the experiments, the largescale image datasets are classified with a DDRM implementation on Hadoop MapReduce, which shows high scalability and resilience.
1607.00509
Evangelos Psomakelis Mr
Evangelos Psomakelis, Fotis Aisopos, Antonios Litke, Konstantinos Tserpes, Magdalini Kardara, Pablo Mart\'inez Campo
Big IoT and social networking data for smart cities: Algorithmic improvements on Big Data Analysis in the context of RADICAL city applications
Conference
null
null
null
cs.CY cs.LG cs.SI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we present a SOA (Service Oriented Architecture)-based platform, enabling the retrieval and analysis of big datasets stemming from social networking (SN) sites and Internet of Things (IoT) devices, collected by smart city applications and socially-aware data aggregation services. A large set of city applications in the areas of Participating Urbanism, Augmented Reality and Sound-Mapping throughout participating cities is being applied, resulting into produced sets of millions of user-generated events and online SN reports fed into the RADICAL platform. Moreover, we study the application of data analytics such as sentiment analysis to the combined IoT and SN data saved into an SQL database, further investigating algorithmic and configurations to minimize delays in dataset processing and results retrieval.
[ { "version": "v1", "created": "Sat, 2 Jul 2016 13:35:02 GMT" } ]
2016-07-05T00:00:00
[ [ "Psomakelis", "Evangelos", "" ], [ "Aisopos", "Fotis", "" ], [ "Litke", "Antonios", "" ], [ "Tserpes", "Konstantinos", "" ], [ "Kardara", "Magdalini", "" ], [ "Campo", "Pablo Martínez", "" ] ]
TITLE: Big IoT and social networking data for smart cities: Algorithmic improvements on Big Data Analysis in the context of RADICAL city applications ABSTRACT: In this paper we present a SOA (Service Oriented Architecture)-based platform, enabling the retrieval and analysis of big datasets stemming from social networking (SN) sites and Internet of Things (IoT) devices, collected by smart city applications and socially-aware data aggregation services. A large set of city applications in the areas of Participating Urbanism, Augmented Reality and Sound-Mapping throughout participating cities is being applied, resulting into produced sets of millions of user-generated events and online SN reports fed into the RADICAL platform. Moreover, we study the application of data analytics such as sentiment analysis to the combined IoT and SN data saved into an SQL database, further investigating algorithmic and configurations to minimize delays in dataset processing and results retrieval.
1607.00548
Melanie Mitchell
Max H. Quinn, Anthony D. Rhodes, Melanie Mitchell
Active Object Localization in Visual Situations
14 pages
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We describe a method for performing active localization of objects in instances of visual situations. A visual situation is an abstract concept---e.g., "a boxing match", "a birthday party", "walking the dog", "waiting for a bus"---whose image instantiations are linked more by their common spatial and semantic structure than by low-level visual similarity. Our system combines given and learned knowledge of the structure of a particular situation, and adapts that knowledge to a new situation instance as it actively searches for objects. More specifically, the system learns a set of probability distributions describing spatial and other relationships among relevant objects. The system uses those distributions to iteratively sample object proposals on a test image, but also continually uses information from those object proposals to adaptively modify the distributions based on what the system has detected. We test our approach's ability to efficiently localize objects, using a situation-specific image dataset created by our group. We compare the results with several baselines and variations on our method, and demonstrate the strong benefit of using situation knowledge and active context-driven localization. Finally, we contrast our method with several other approaches that use context as well as active search for object localization in images.
[ { "version": "v1", "created": "Sat, 2 Jul 2016 18:43:07 GMT" } ]
2016-07-05T00:00:00
[ [ "Quinn", "Max H.", "" ], [ "Rhodes", "Anthony D.", "" ], [ "Mitchell", "Melanie", "" ] ]
TITLE: Active Object Localization in Visual Situations ABSTRACT: We describe a method for performing active localization of objects in instances of visual situations. A visual situation is an abstract concept---e.g., "a boxing match", "a birthday party", "walking the dog", "waiting for a bus"---whose image instantiations are linked more by their common spatial and semantic structure than by low-level visual similarity. Our system combines given and learned knowledge of the structure of a particular situation, and adapts that knowledge to a new situation instance as it actively searches for objects. More specifically, the system learns a set of probability distributions describing spatial and other relationships among relevant objects. The system uses those distributions to iteratively sample object proposals on a test image, but also continually uses information from those object proposals to adaptively modify the distributions based on what the system has detected. We test our approach's ability to efficiently localize objects, using a situation-specific image dataset created by our group. We compare the results with several baselines and variations on our method, and demonstrate the strong benefit of using situation knowledge and active context-driven localization. Finally, we contrast our method with several other approaches that use context as well as active search for object localization in images.
1607.00556
Ehsan Hosseini-Asl
Ehsan Hosseini-Asl, Georgy Gimel'farb, Ayman El-Baz
Alzheimer's Disease Diagnostics by a Deeply Supervised Adaptable 3D Convolutional Network
null
null
null
null
cs.LG q-bio.NC stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Early diagnosis, playing an important role in preventing progress and treating the Alzheimer's disease (AD), is based on classification of features extracted from brain images. The features have to accurately capture main AD-related variations of anatomical brain structures, such as, e.g., ventricles size, hippocampus shape, cortical thickness, and brain volume. This paper proposes to predict the AD with a deep 3D convolutional neural network (3D-CNN), which can learn generic features capturing AD biomarkers and adapt to different domain datasets. The 3D-CNN is built upon a 3D convolutional autoencoder, which is pre-trained to capture anatomical shape variations in structural brain MRI scans. Fully connected upper layers of the 3D-CNN are then fine-tuned for each task-specific AD classification. Experiments on the \emph{ADNI} MRI dataset with no skull-stripping preprocessing have shown our 3D-CNN outperforms several conventional classifiers by accuracy and robustness. Abilities of the 3D-CNN to generalize the features learnt and adapt to other domains have been validated on the \emph{CADDementia} dataset.
[ { "version": "v1", "created": "Sat, 2 Jul 2016 19:55:56 GMT" } ]
2016-07-05T00:00:00
[ [ "Hosseini-Asl", "Ehsan", "" ], [ "Gimel'farb", "Georgy", "" ], [ "El-Baz", "Ayman", "" ] ]
TITLE: Alzheimer's Disease Diagnostics by a Deeply Supervised Adaptable 3D Convolutional Network ABSTRACT: Early diagnosis, playing an important role in preventing progress and treating the Alzheimer's disease (AD), is based on classification of features extracted from brain images. The features have to accurately capture main AD-related variations of anatomical brain structures, such as, e.g., ventricles size, hippocampus shape, cortical thickness, and brain volume. This paper proposes to predict the AD with a deep 3D convolutional neural network (3D-CNN), which can learn generic features capturing AD biomarkers and adapt to different domain datasets. The 3D-CNN is built upon a 3D convolutional autoencoder, which is pre-trained to capture anatomical shape variations in structural brain MRI scans. Fully connected upper layers of the 3D-CNN are then fine-tuned for each task-specific AD classification. Experiments on the \emph{ADNI} MRI dataset with no skull-stripping preprocessing have shown our 3D-CNN outperforms several conventional classifiers by accuracy and robustness. Abilities of the 3D-CNN to generalize the features learnt and adapt to other domains have been validated on the \emph{CADDementia} dataset.
1607.00577
Le Dong
Le Dong, Zhiyu Lin, Yan Liang, Ling He, Ning Zhang, Qi Chen, Xiaochun Cao, Ebroul lzquierdo
A Hierarchical Distributed Processing Framework for Big Image Data
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper introduces an effective processing framework nominated ICP (Image Cloud Processing) to powerfully cope with the data explosion in image processing field. While most previous researches focus on optimizing the image processing algorithms to gain higher efficiency, our work dedicates to providing a general framework for those image processing algorithms, which can be implemented in parallel so as to achieve a boost in time efficiency without compromising the results performance along with the increasing image scale. The proposed ICP framework consists of two mechanisms, i.e. SICP (Static ICP) and DICP (Dynamic ICP). Specifically, SICP is aimed at processing the big image data pre-stored in the distributed system, while DICP is proposed for dynamic input. To accomplish SICP, two novel data representations named P-Image and Big-Image are designed to cooperate with MapReduce to achieve more optimized configuration and higher efficiency. DICP is implemented through a parallel processing procedure working with the traditional processing mechanism of the distributed system. Representative results of comprehensive experiments on the challenging ImageNet dataset are selected to validate the capacity of our proposed ICP framework over the traditional state-of-the-art methods, both in time efficiency and quality of results.
[ { "version": "v1", "created": "Sun, 3 Jul 2016 02:16:49 GMT" } ]
2016-07-05T00:00:00
[ [ "Dong", "Le", "" ], [ "Lin", "Zhiyu", "" ], [ "Liang", "Yan", "" ], [ "He", "Ling", "" ], [ "Zhang", "Ning", "" ], [ "Chen", "Qi", "" ], [ "Cao", "Xiaochun", "" ], [ "lzquierdo", "Ebroul", "" ] ]
TITLE: A Hierarchical Distributed Processing Framework for Big Image Data ABSTRACT: This paper introduces an effective processing framework nominated ICP (Image Cloud Processing) to powerfully cope with the data explosion in image processing field. While most previous researches focus on optimizing the image processing algorithms to gain higher efficiency, our work dedicates to providing a general framework for those image processing algorithms, which can be implemented in parallel so as to achieve a boost in time efficiency without compromising the results performance along with the increasing image scale. The proposed ICP framework consists of two mechanisms, i.e. SICP (Static ICP) and DICP (Dynamic ICP). Specifically, SICP is aimed at processing the big image data pre-stored in the distributed system, while DICP is proposed for dynamic input. To accomplish SICP, two novel data representations named P-Image and Big-Image are designed to cooperate with MapReduce to achieve more optimized configuration and higher efficiency. DICP is implemented through a parallel processing procedure working with the traditional processing mechanism of the distributed system. Representative results of comprehensive experiments on the challenging ImageNet dataset are selected to validate the capacity of our proposed ICP framework over the traditional state-of-the-art methods, both in time efficiency and quality of results.
1607.00582
Qi Dou
Qi Dou, Hao Chen, Yueming Jin, Lequan Yu, Jing Qin, Pheng-Ann Heng
3D Deeply Supervised Network for Automatic Liver Segmentation from CT Volumes
Accepted to MICCAI 2016
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Automatic liver segmentation from CT volumes is a crucial prerequisite yet challenging task for computer-aided hepatic disease diagnosis and treatment. In this paper, we present a novel 3D deeply supervised network (3D DSN) to address this challenging task. The proposed 3D DSN takes advantage of a fully convolutional architecture which performs efficient end-to-end learning and inference. More importantly, we introduce a deep supervision mechanism during the learning process to combat potential optimization difficulties, and thus the model can acquire a much faster convergence rate and more powerful discrimination capability. On top of the high-quality score map produced by the 3D DSN, a conditional random field model is further employed to obtain refined segmentation results. We evaluated our framework on the public MICCAI-SLiver07 dataset. Extensive experiments demonstrated that our method achieves competitive segmentation results to state-of-the-art approaches with a much faster processing speed.
[ { "version": "v1", "created": "Sun, 3 Jul 2016 02:52:56 GMT" } ]
2016-07-05T00:00:00
[ [ "Dou", "Qi", "" ], [ "Chen", "Hao", "" ], [ "Jin", "Yueming", "" ], [ "Yu", "Lequan", "" ], [ "Qin", "Jing", "" ], [ "Heng", "Pheng-Ann", "" ] ]
TITLE: 3D Deeply Supervised Network for Automatic Liver Segmentation from CT Volumes ABSTRACT: Automatic liver segmentation from CT volumes is a crucial prerequisite yet challenging task for computer-aided hepatic disease diagnosis and treatment. In this paper, we present a novel 3D deeply supervised network (3D DSN) to address this challenging task. The proposed 3D DSN takes advantage of a fully convolutional architecture which performs efficient end-to-end learning and inference. More importantly, we introduce a deep supervision mechanism during the learning process to combat potential optimization difficulties, and thus the model can acquire a much faster convergence rate and more powerful discrimination capability. On top of the high-quality score map produced by the 3D DSN, a conditional random field model is further employed to obtain refined segmentation results. We evaluated our framework on the public MICCAI-SLiver07 dataset. Extensive experiments demonstrated that our method achieves competitive segmentation results to state-of-the-art approaches with a much faster processing speed.
1607.00598
Yuzhuo Ren
Yuzhuo Ren, Chen Chen, Shangwen Li, and C.-C. Jay Kuo
A Coarse-to-Fine Indoor Layout Estimation (CFILE) Method
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The task of estimating the spatial layout of cluttered indoor scenes from a single RGB image is addressed in this work. Existing solutions to this problems largely rely on hand-craft features and vanishing lines, and they often fail in highly cluttered indoor rooms. The proposed coarse-to-fine indoor layout estimation (CFILE) method consists of two stages: 1) coarse layout estimation; and 2) fine layout localization. In the first stage, we adopt a fully convolutional neural network (FCN) to obtain a coarse-scale room layout estimate that is close to the ground truth globally. The proposed FCN considers combines the layout contour property and the surface property so as to provide a robust estimate in the presence of cluttered objects. In the second stage, we formulate an optimization framework that enforces several constraints such as layout contour straightness, surface smoothness and geometric constraints for layout detail refinement. Our proposed system offers the state-of-the-art performance on two commonly used benchmark datasets.
[ { "version": "v1", "created": "Sun, 3 Jul 2016 05:55:47 GMT" } ]
2016-07-05T00:00:00
[ [ "Ren", "Yuzhuo", "" ], [ "Chen", "Chen", "" ], [ "Li", "Shangwen", "" ], [ "Kuo", "C. -C. Jay", "" ] ]
TITLE: A Coarse-to-Fine Indoor Layout Estimation (CFILE) Method ABSTRACT: The task of estimating the spatial layout of cluttered indoor scenes from a single RGB image is addressed in this work. Existing solutions to this problems largely rely on hand-craft features and vanishing lines, and they often fail in highly cluttered indoor rooms. The proposed coarse-to-fine indoor layout estimation (CFILE) method consists of two stages: 1) coarse layout estimation; and 2) fine layout localization. In the first stage, we adopt a fully convolutional neural network (FCN) to obtain a coarse-scale room layout estimate that is close to the ground truth globally. The proposed FCN considers combines the layout contour property and the surface property so as to provide a robust estimate in the presence of cluttered objects. In the second stage, we formulate an optimization framework that enforces several constraints such as layout contour straightness, surface smoothness and geometric constraints for layout detail refinement. Our proposed system offers the state-of-the-art performance on two commonly used benchmark datasets.
1607.00659
Kha Gia Quach
Kha Gia Quach, Chi Nhan Duong, Khoa Luu and Tien D. Bui
Robust Deep Appearance Models
6 pages, 8 figures, submitted to ICPR 2016
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper presents a novel Robust Deep Appearance Models to learn the non-linear correlation between shape and texture of face images. In this approach, two crucial components of face images, i.e. shape and texture, are represented by Deep Boltzmann Machines and Robust Deep Boltzmann Machines (RDBM), respectively. The RDBM, an alternative form of Robust Boltzmann Machines, can separate corrupted/occluded pixels in the texture modeling to achieve better reconstruction results. The two models are connected by Restricted Boltzmann Machines at the top layer to jointly learn and capture the variations of both facial shapes and appearances. This paper also introduces new fitting algorithms with occlusion awareness through the mask obtained from the RDBM reconstruction. The proposed approach is evaluated in various applications by using challenging face datasets, i.e. Labeled Face Parts in the Wild (LFPW), Helen, EURECOM and AR databases, to demonstrate its robustness and capabilities.
[ { "version": "v1", "created": "Sun, 3 Jul 2016 17:31:30 GMT" } ]
2016-07-05T00:00:00
[ [ "Quach", "Kha Gia", "" ], [ "Duong", "Chi Nhan", "" ], [ "Luu", "Khoa", "" ], [ "Bui", "Tien D.", "" ] ]
TITLE: Robust Deep Appearance Models ABSTRACT: This paper presents a novel Robust Deep Appearance Models to learn the non-linear correlation between shape and texture of face images. In this approach, two crucial components of face images, i.e. shape and texture, are represented by Deep Boltzmann Machines and Robust Deep Boltzmann Machines (RDBM), respectively. The RDBM, an alternative form of Robust Boltzmann Machines, can separate corrupted/occluded pixels in the texture modeling to achieve better reconstruction results. The two models are connected by Restricted Boltzmann Machines at the top layer to jointly learn and capture the variations of both facial shapes and appearances. This paper also introduces new fitting algorithms with occlusion awareness through the mask obtained from the RDBM reconstruction. The proposed approach is evaluated in various applications by using challenging face datasets, i.e. Labeled Face Parts in the Wild (LFPW), Helen, EURECOM and AR databases, to demonstrate its robustness and capabilities.
1607.00719
Le Dong
Gaipeng Kong, Le Dong, Wenpu Dong, Liang Zheng, Qi Tian
Coarse2Fine: Two-Layer Fusion For Image Retrieval
null
null
null
null
cs.MM cs.CV cs.IR
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper addresses the problem of large-scale image retrieval. We propose a two-layer fusion method which takes advantage of global and local cues and ranks database images from coarse to fine (C2F). Departing from the previous methods fusing multiple image descriptors simultaneously, C2F is featured by a layered procedure composed by filtering and refining. In particular, C2F consists of three components. 1) Distractor filtering. With holistic representations, noise images are filtered out from the database, so the number of candidate images to be used for comparison with the query can be greatly reduced. 2) Adaptive weighting. For a certain query, the similarity of candidate images can be estimated by holistic similarity scores in complementary to the local ones. 3) Candidate refining. Accurate retrieval is conducted via local features, combining the pre-computed adaptive weights. Experiments are presented on two benchmarks, \emph{i.e.,} Holidays and Ukbench datasets. We show that our method outperforms recent fusion methods in terms of storage consumption and computation complexity, and that the accuracy is competitive to the state-of-the-arts.
[ { "version": "v1", "created": "Mon, 4 Jul 2016 01:56:20 GMT" } ]
2016-07-05T00:00:00
[ [ "Kong", "Gaipeng", "" ], [ "Dong", "Le", "" ], [ "Dong", "Wenpu", "" ], [ "Zheng", "Liang", "" ], [ "Tian", "Qi", "" ] ]
TITLE: Coarse2Fine: Two-Layer Fusion For Image Retrieval ABSTRACT: This paper addresses the problem of large-scale image retrieval. We propose a two-layer fusion method which takes advantage of global and local cues and ranks database images from coarse to fine (C2F). Departing from the previous methods fusing multiple image descriptors simultaneously, C2F is featured by a layered procedure composed by filtering and refining. In particular, C2F consists of three components. 1) Distractor filtering. With holistic representations, noise images are filtered out from the database, so the number of candidate images to be used for comparison with the query can be greatly reduced. 2) Adaptive weighting. For a certain query, the similarity of candidate images can be estimated by holistic similarity scores in complementary to the local ones. 3) Candidate refining. Accurate retrieval is conducted via local features, combining the pre-computed adaptive weights. Experiments are presented on two benchmarks, \emph{i.e.,} Holidays and Ukbench datasets. We show that our method outperforms recent fusion methods in terms of storage consumption and computation complexity, and that the accuracy is competitive to the state-of-the-arts.
1510.03519
Janarthanan Rajendran
Janarthanan Rajendran, Mitesh M. Khapra, Sarath Chandar, Balaraman Ravindran
Bridge Correlational Neural Networks for Multilingual Multimodal Representation Learning
Published at NAACL-HLT 2016
null
null
null
cs.CL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recently there has been a lot of interest in learning common representations for multiple views of data. Typically, such common representations are learned using a parallel corpus between the two views (say, 1M images and their English captions). In this work, we address a real-world scenario where no direct parallel data is available between two views of interest (say, $V_1$ and $V_2$) but parallel data is available between each of these views and a pivot view ($V_3$). We propose a model for learning a common representation for $V_1$, $V_2$ and $V_3$ using only the parallel data available between $V_1V_3$ and $V_2V_3$. The proposed model is generic and even works when there are $n$ views of interest and only one pivot view which acts as a bridge between them. There are two specific downstream applications that we focus on (i) transfer learning between languages $L_1$,$L_2$,...,$L_n$ using a pivot language $L$ and (ii) cross modal access between images and a language $L_1$ using a pivot language $L_2$. Our model achieves state-of-the-art performance in multilingual document classification on the publicly available multilingual TED corpus and promising results in multilingual multimodal retrieval on a new dataset created and released as a part of this work.
[ { "version": "v1", "created": "Tue, 13 Oct 2015 03:25:18 GMT" }, { "version": "v2", "created": "Sat, 6 Feb 2016 07:44:01 GMT" }, { "version": "v3", "created": "Fri, 1 Jul 2016 09:01:19 GMT" } ]
2016-07-04T00:00:00
[ [ "Rajendran", "Janarthanan", "" ], [ "Khapra", "Mitesh M.", "" ], [ "Chandar", "Sarath", "" ], [ "Ravindran", "Balaraman", "" ] ]
TITLE: Bridge Correlational Neural Networks for Multilingual Multimodal Representation Learning ABSTRACT: Recently there has been a lot of interest in learning common representations for multiple views of data. Typically, such common representations are learned using a parallel corpus between the two views (say, 1M images and their English captions). In this work, we address a real-world scenario where no direct parallel data is available between two views of interest (say, $V_1$ and $V_2$) but parallel data is available between each of these views and a pivot view ($V_3$). We propose a model for learning a common representation for $V_1$, $V_2$ and $V_3$ using only the parallel data available between $V_1V_3$ and $V_2V_3$. The proposed model is generic and even works when there are $n$ views of interest and only one pivot view which acts as a bridge between them. There are two specific downstream applications that we focus on (i) transfer learning between languages $L_1$,$L_2$,...,$L_n$ using a pivot language $L$ and (ii) cross modal access between images and a language $L_1$ using a pivot language $L_2$. Our model achieves state-of-the-art performance in multilingual document classification on the publicly available multilingual TED corpus and promising results in multilingual multimodal retrieval on a new dataset created and released as a part of this work.
1511.05526
Matthew Walter
Zhengyang Wu and Mohit Bansal and Matthew R. Walter
Learning Articulated Motion Models from Visual and Lingual Signals
null
null
null
null
cs.RO cs.CL cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In order for robots to operate effectively in homes and workplaces, they must be able to manipulate the articulated objects common within environments built for and by humans. Previous work learns kinematic models that prescribe this manipulation from visual demonstrations. Lingual signals, such as natural language descriptions and instructions, offer a complementary means of conveying knowledge of such manipulation models and are suitable to a wide range of interactions (e.g., remote manipulation). In this paper, we present a multimodal learning framework that incorporates both visual and lingual information to estimate the structure and parameters that define kinematic models of articulated objects. The visual signal takes the form of an RGB-D image stream that opportunistically captures object motion in an unprepared scene. Accompanying natural language descriptions of the motion constitute the lingual signal. We present a probabilistic language model that uses word embeddings to associate lingual verbs with their corresponding kinematic structures. By exploiting the complementary nature of the visual and lingual input, our method infers correct kinematic structures for various multiple-part objects on which the previous state-of-the-art, visual-only system fails. We evaluate our multimodal learning framework on a dataset comprised of a variety of household objects, and demonstrate a 36% improvement in model accuracy over the vision-only baseline.
[ { "version": "v1", "created": "Tue, 17 Nov 2015 19:55:34 GMT" }, { "version": "v2", "created": "Fri, 1 Jul 2016 14:53:28 GMT" } ]
2016-07-04T00:00:00
[ [ "Wu", "Zhengyang", "" ], [ "Bansal", "Mohit", "" ], [ "Walter", "Matthew R.", "" ] ]
TITLE: Learning Articulated Motion Models from Visual and Lingual Signals ABSTRACT: In order for robots to operate effectively in homes and workplaces, they must be able to manipulate the articulated objects common within environments built for and by humans. Previous work learns kinematic models that prescribe this manipulation from visual demonstrations. Lingual signals, such as natural language descriptions and instructions, offer a complementary means of conveying knowledge of such manipulation models and are suitable to a wide range of interactions (e.g., remote manipulation). In this paper, we present a multimodal learning framework that incorporates both visual and lingual information to estimate the structure and parameters that define kinematic models of articulated objects. The visual signal takes the form of an RGB-D image stream that opportunistically captures object motion in an unprepared scene. Accompanying natural language descriptions of the motion constitute the lingual signal. We present a probabilistic language model that uses word embeddings to associate lingual verbs with their corresponding kinematic structures. By exploiting the complementary nature of the visual and lingual input, our method infers correct kinematic structures for various multiple-part objects on which the previous state-of-the-art, visual-only system fails. We evaluate our multimodal learning framework on a dataset comprised of a variety of household objects, and demonstrate a 36% improvement in model accuracy over the vision-only baseline.
1603.07252
Jianpeng Cheng J
Jianpeng Cheng, Mirella Lapata
Neural Summarization by Extracting Sentences and Words
ACL2016 conference paper with appendix
null
null
null
cs.CL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Traditional approaches to extractive summarization rely heavily on human-engineered features. In this work we propose a data-driven approach based on neural networks and continuous sentence features. We develop a general framework for single-document summarization composed of a hierarchical document encoder and an attention-based extractor. This architecture allows us to develop different classes of summarization models which can extract sentences or words. We train our models on large scale corpora containing hundreds of thousands of document-summary pairs. Experimental results on two summarization datasets demonstrate that our models obtain results comparable to the state of the art without any access to linguistic annotation.
[ { "version": "v1", "created": "Wed, 23 Mar 2016 16:05:46 GMT" }, { "version": "v2", "created": "Tue, 7 Jun 2016 13:41:50 GMT" }, { "version": "v3", "created": "Fri, 1 Jul 2016 03:16:03 GMT" } ]
2016-07-04T00:00:00
[ [ "Cheng", "Jianpeng", "" ], [ "Lapata", "Mirella", "" ] ]
TITLE: Neural Summarization by Extracting Sentences and Words ABSTRACT: Traditional approaches to extractive summarization rely heavily on human-engineered features. In this work we propose a data-driven approach based on neural networks and continuous sentence features. We develop a general framework for single-document summarization composed of a hierarchical document encoder and an attention-based extractor. This architecture allows us to develop different classes of summarization models which can extract sentences or words. We train our models on large scale corpora containing hundreds of thousands of document-summary pairs. Experimental results on two summarization datasets demonstrate that our models obtain results comparable to the state of the art without any access to linguistic annotation.
1607.00067
Fariba Yousefi
Fariba Yousefi, Zhenwen Dai, Carl Henrik Ek, Neil Lawrence
Unsupervised Learning with Imbalanced Data via Structure Consolidation Latent Variable Model
ICLR 2016 Workshop
null
null
null
cs.LG stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Unsupervised learning on imbalanced data is challenging because, when given imbalanced data, current model is often dominated by the major category and ignores the categories with small amount of data. We develop a latent variable model that can cope with imbalanced data by dividing the latent space into a shared space and a private space. Based on Gaussian Process Latent Variable Models, we propose a new kernel formulation that enables the separation of latent space and derives an efficient variational inference method. The performance of our model is demonstrated with an imbalanced medical image dataset.
[ { "version": "v1", "created": "Thu, 30 Jun 2016 22:25:20 GMT" } ]
2016-07-04T00:00:00
[ [ "Yousefi", "Fariba", "" ], [ "Dai", "Zhenwen", "" ], [ "Ek", "Carl Henrik", "" ], [ "Lawrence", "Neil", "" ] ]
TITLE: Unsupervised Learning with Imbalanced Data via Structure Consolidation Latent Variable Model ABSTRACT: Unsupervised learning on imbalanced data is challenging because, when given imbalanced data, current model is often dominated by the major category and ignores the categories with small amount of data. We develop a latent variable model that can cope with imbalanced data by dividing the latent space into a shared space and a private space. Based on Gaussian Process Latent Variable Models, we propose a new kernel formulation that enables the separation of latent space and derives an efficient variational inference method. The performance of our model is demonstrated with an imbalanced medical image dataset.
1607.00070
Layla El Asri
Layla El Asri and Jing He and Kaheer Suleman
A Sequence-to-Sequence Model for User Simulation in Spoken Dialogue Systems
Accepted for publication at Interspeech 2016
null
null
null
cs.CL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
User simulation is essential for generating enough data to train a statistical spoken dialogue system. Previous models for user simulation suffer from several drawbacks, such as the inability to take dialogue history into account, the need of rigid structure to ensure coherent user behaviour, heavy dependence on a specific domain, the inability to output several user intentions during one dialogue turn, or the requirement of a summarized action space for tractability. This paper introduces a data-driven user simulator based on an encoder-decoder recurrent neural network. The model takes as input a sequence of dialogue contexts and outputs a sequence of dialogue acts corresponding to user intentions. The dialogue contexts include information about the machine acts and the status of the user goal. We show on the Dialogue State Tracking Challenge 2 (DSTC2) dataset that the sequence-to-sequence model outperforms an agenda-based simulator and an n-gram simulator, according to F-score. Furthermore, we show how this model can be used on the original action space and thereby models user behaviour with finer granularity.
[ { "version": "v1", "created": "Thu, 30 Jun 2016 22:51:00 GMT" } ]
2016-07-04T00:00:00
[ [ "Asri", "Layla El", "" ], [ "He", "Jing", "" ], [ "Suleman", "Kaheer", "" ] ]
TITLE: A Sequence-to-Sequence Model for User Simulation in Spoken Dialogue Systems ABSTRACT: User simulation is essential for generating enough data to train a statistical spoken dialogue system. Previous models for user simulation suffer from several drawbacks, such as the inability to take dialogue history into account, the need of rigid structure to ensure coherent user behaviour, heavy dependence on a specific domain, the inability to output several user intentions during one dialogue turn, or the requirement of a summarized action space for tractability. This paper introduces a data-driven user simulator based on an encoder-decoder recurrent neural network. The model takes as input a sequence of dialogue contexts and outputs a sequence of dialogue acts corresponding to user intentions. The dialogue contexts include information about the machine acts and the status of the user goal. We show on the Dialogue State Tracking Challenge 2 (DSTC2) dataset that the sequence-to-sequence model outperforms an agenda-based simulator and an n-gram simulator, according to F-score. Furthermore, we show how this model can be used on the original action space and thereby models user behaviour with finer granularity.
1607.00110
Iman Alodah
Iman Alodah and Jennifer Neville
Combining Gradient Boosting Machines with Collective Inference to Predict Continuous Values
7 pages, 3 Figures, Sixth International Workshop on Statistical Relational AI
null
null
null
cs.LG stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Gradient boosting of regression trees is a competitive procedure for learning predictive models of continuous data that fits the data with an additive non-parametric model. The classic version of gradient boosting assumes that the data is independent and identically distributed. However, relational data with interdependent, linked instances is now common and the dependencies in such data can be exploited to improve predictive performance. Collective inference is one approach to exploit relational correlation patterns and significantly reduce classification error. However, much of the work on collective learning and inference has focused on discrete prediction tasks rather than continuous. %target values has not got that attention in terms of collective inference. In this work, we investigate how to combine these two paradigms together to improve regression in relational domains. Specifically, we propose a boosting algorithm for learning a collective inference model that predicts a continuous target variable. In the algorithm, we learn a basic relational model, collectively infer the target values, and then iteratively learn relational models to predict the residuals. We evaluate our proposed algorithm on a real network dataset and show that it outperforms alternative boosting methods. However, our investigation also revealed that the relational features interact together to produce better predictions.
[ { "version": "v1", "created": "Fri, 1 Jul 2016 05:21:15 GMT" } ]
2016-07-04T00:00:00
[ [ "Alodah", "Iman", "" ], [ "Neville", "Jennifer", "" ] ]
TITLE: Combining Gradient Boosting Machines with Collective Inference to Predict Continuous Values ABSTRACT: Gradient boosting of regression trees is a competitive procedure for learning predictive models of continuous data that fits the data with an additive non-parametric model. The classic version of gradient boosting assumes that the data is independent and identically distributed. However, relational data with interdependent, linked instances is now common and the dependencies in such data can be exploited to improve predictive performance. Collective inference is one approach to exploit relational correlation patterns and significantly reduce classification error. However, much of the work on collective learning and inference has focused on discrete prediction tasks rather than continuous. %target values has not got that attention in terms of collective inference. In this work, we investigate how to combine these two paradigms together to improve regression in relational domains. Specifically, we propose a boosting algorithm for learning a collective inference model that predicts a continuous target variable. In the algorithm, we learn a basic relational model, collectively infer the target values, and then iteratively learn relational models to predict the residuals. We evaluate our proposed algorithm on a real network dataset and show that it outperforms alternative boosting methods. However, our investigation also revealed that the relational features interact together to produce better predictions.
1607.00136
Collins Leke
Collins Leke and Tshilidzi Marwala
Missing Data Estimation in High-Dimensional Datasets: A Swarm Intelligence-Deep Neural Network Approach
12 pages, 3 figures
null
null
null
cs.AI cs.LG stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we examine the problem of missing data in high-dimensional datasets by taking into consideration the Missing Completely at Random and Missing at Random mechanisms, as well as theArbitrary missing pattern. Additionally, this paper employs a methodology based on Deep Learning and Swarm Intelligence algorithms in order to provide reliable estimates for missing data. The deep learning technique is used to extract features from the input data via an unsupervised learning approach by modeling the data distribution based on the input. This deep learning technique is then used as part of the objective function for the swarm intelligence technique in order to estimate the missing data after a supervised fine-tuning phase by minimizing an error function based on the interrelationship and correlation between features in the dataset. The investigated methodology in this paper therefore has longer running times, however, the promising potential outcomes justify the trade-off. Also, basic knowledge of statistics is presumed.
[ { "version": "v1", "created": "Fri, 1 Jul 2016 07:34:50 GMT" } ]
2016-07-04T00:00:00
[ [ "Leke", "Collins", "" ], [ "Marwala", "Tshilidzi", "" ] ]
TITLE: Missing Data Estimation in High-Dimensional Datasets: A Swarm Intelligence-Deep Neural Network Approach ABSTRACT: In this paper, we examine the problem of missing data in high-dimensional datasets by taking into consideration the Missing Completely at Random and Missing at Random mechanisms, as well as theArbitrary missing pattern. Additionally, this paper employs a methodology based on Deep Learning and Swarm Intelligence algorithms in order to provide reliable estimates for missing data. The deep learning technique is used to extract features from the input data via an unsupervised learning approach by modeling the data distribution based on the input. This deep learning technique is then used as part of the objective function for the swarm intelligence technique in order to estimate the missing data after a supervised fine-tuning phase by minimizing an error function based on the interrelationship and correlation between features in the dataset. The investigated methodology in this paper therefore has longer running times, however, the promising potential outcomes justify the trade-off. Also, basic knowledge of statistics is presumed.
1607.00137
Chunlei Peng
Chunlei Peng, Xinbo Gao, Nannan Wang, Jie Li
Sparse Graphical Representation based Discriminant Analysis for Heterogeneous Face Recognition
13 pages, 17 figures, submitted to IEEE TNNLS
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Face images captured in heterogeneous environments, e.g., sketches generated by the artists or composite-generation software, photos taken by common cameras and infrared images captured by corresponding infrared imaging devices, usually subject to large texture (i.e., style) differences. This results in heavily degraded performance of conventional face recognition methods in comparison with the performance on images captured in homogeneous environments. In this paper, we propose a novel sparse graphical representation based discriminant analysis (SGR-DA) approach to address aforementioned face recognition in heterogeneous scenarios. An adaptive sparse graphical representation scheme is designed to represent heterogeneous face images, where a Markov networks model is constructed to generate adaptive sparse vectors. To handle the complex facial structure and further improve the discriminability, a spatial partition-based discriminant analysis framework is presented to refine the adaptive sparse vectors for face matching. We conducted experiments on six commonly used heterogeneous face datasets and experimental results illustrate that our proposed SGR-DA approach achieves superior performance in comparison with state-of-the-art methods.
[ { "version": "v1", "created": "Fri, 1 Jul 2016 07:41:25 GMT" } ]
2016-07-04T00:00:00
[ [ "Peng", "Chunlei", "" ], [ "Gao", "Xinbo", "" ], [ "Wang", "Nannan", "" ], [ "Li", "Jie", "" ] ]
TITLE: Sparse Graphical Representation based Discriminant Analysis for Heterogeneous Face Recognition ABSTRACT: Face images captured in heterogeneous environments, e.g., sketches generated by the artists or composite-generation software, photos taken by common cameras and infrared images captured by corresponding infrared imaging devices, usually subject to large texture (i.e., style) differences. This results in heavily degraded performance of conventional face recognition methods in comparison with the performance on images captured in homogeneous environments. In this paper, we propose a novel sparse graphical representation based discriminant analysis (SGR-DA) approach to address aforementioned face recognition in heterogeneous scenarios. An adaptive sparse graphical representation scheme is designed to represent heterogeneous face images, where a Markov networks model is constructed to generate adaptive sparse vectors. To handle the complex facial structure and further improve the discriminability, a spatial partition-based discriminant analysis framework is presented to refine the adaptive sparse vectors for face matching. We conducted experiments on six commonly used heterogeneous face datasets and experimental results illustrate that our proposed SGR-DA approach achieves superior performance in comparison with state-of-the-art methods.
1607.00146
Kush Bhatia
Kush Bhatia, Prateek Jain, Parameswaran Kamalaruban, Purushottam Kar
Efficient and Consistent Robust Time Series Analysis
null
null
null
null
cs.LG stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the problem of robust time series analysis under the standard auto-regressive (AR) time series model in the presence of arbitrary outliers. We devise an efficient hard thresholding based algorithm which can obtain a consistent estimate of the optimal AR model despite a large fraction of the time series points being corrupted. Our algorithm alternately estimates the corrupted set of points and the model parameters, and is inspired by recent advances in robust regression and hard-thresholding methods. However, a direct application of existing techniques is hindered by a critical difference in the time-series domain: each point is correlated with all previous points rendering existing tools inapplicable directly. We show how to overcome this hurdle using novel proof techniques. Using our techniques, we are also able to provide the first efficient and provably consistent estimator for the robust regression problem where a standard linear observation model with white additive noise is corrupted arbitrarily. We illustrate our methods on synthetic datasets and show that our methods indeed are able to consistently recover the optimal parameters despite a large fraction of points being corrupted.
[ { "version": "v1", "created": "Fri, 1 Jul 2016 08:17:27 GMT" } ]
2016-07-04T00:00:00
[ [ "Bhatia", "Kush", "" ], [ "Jain", "Prateek", "" ], [ "Kamalaruban", "Parameswaran", "" ], [ "Kar", "Purushottam", "" ] ]
TITLE: Efficient and Consistent Robust Time Series Analysis ABSTRACT: We study the problem of robust time series analysis under the standard auto-regressive (AR) time series model in the presence of arbitrary outliers. We devise an efficient hard thresholding based algorithm which can obtain a consistent estimate of the optimal AR model despite a large fraction of the time series points being corrupted. Our algorithm alternately estimates the corrupted set of points and the model parameters, and is inspired by recent advances in robust regression and hard-thresholding methods. However, a direct application of existing techniques is hindered by a critical difference in the time-series domain: each point is correlated with all previous points rendering existing tools inapplicable directly. We show how to overcome this hurdle using novel proof techniques. Using our techniques, we are also able to provide the first efficient and provably consistent estimator for the robust regression problem where a standard linear observation model with white additive noise is corrupted arbitrarily. We illustrate our methods on synthetic datasets and show that our methods indeed are able to consistently recover the optimal parameters despite a large fraction of points being corrupted.
1607.00225
Chris Emmery
St\'ephan Tulkens, Chris Emmery, Walter Daelemans
Evaluating Unsupervised Dutch Word Embeddings as a Linguistic Resource
in LREC 2016
null
null
null
cs.CL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Word embeddings have recently seen a strong increase in interest as a result of strong performance gains on a variety of tasks. However, most of this research also underlined the importance of benchmark datasets, and the difficulty of constructing these for a variety of language-specific tasks. Still, many of the datasets used in these tasks could prove to be fruitful linguistic resources, allowing for unique observations into language use and variability. In this paper we demonstrate the performance of multiple types of embeddings, created with both count and prediction-based architectures on a variety of corpora, in two language-specific tasks: relation evaluation, and dialect identification. For the latter, we compare unsupervised methods with a traditional, hand-crafted dictionary. With this research, we provide the embeddings themselves, the relation evaluation task benchmark for use in further research, and demonstrate how the benchmarked embeddings prove a useful unsupervised linguistic resource, effectively used in a downstream task.
[ { "version": "v1", "created": "Fri, 1 Jul 2016 12:48:35 GMT" } ]
2016-07-04T00:00:00
[ [ "Tulkens", "Stéphan", "" ], [ "Emmery", "Chris", "" ], [ "Daelemans", "Walter", "" ] ]
TITLE: Evaluating Unsupervised Dutch Word Embeddings as a Linguistic Resource ABSTRACT: Word embeddings have recently seen a strong increase in interest as a result of strong performance gains on a variety of tasks. However, most of this research also underlined the importance of benchmark datasets, and the difficulty of constructing these for a variety of language-specific tasks. Still, many of the datasets used in these tasks could prove to be fruitful linguistic resources, allowing for unique observations into language use and variability. In this paper we demonstrate the performance of multiple types of embeddings, created with both count and prediction-based architectures on a variety of corpora, in two language-specific tasks: relation evaluation, and dialect identification. For the latter, we compare unsupervised methods with a traditional, hand-crafted dictionary. With this research, we provide the embeddings themselves, the relation evaluation task benchmark for use in further research, and demonstrate how the benchmarked embeddings prove a useful unsupervised linguistic resource, effectively used in a downstream task.
1607.00273
Pablo F. Alcantarilla Dr.
Pablo F. Alcantarilla and Oliver J. Woodford
Noise Models in Feature-based Stereo Visual Odometry
null
null
null
null
cs.RO cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Feature-based visual structure and motion reconstruction pipelines, common in visual odometry and large-scale reconstruction from photos, use the location of corresponding features in different images to determine the 3D structure of the scene, as well as the camera parameters associated with each image. The noise model, which defines the likelihood of the location of each feature in each image, is a key factor in the accuracy of such pipelines, alongside optimization strategy. Many different noise models have been proposed in the literature; in this paper we investigate the performance of several. We evaluate these models specifically w.r.t. stereo visual odometry, as this task is both simple (camera intrinsics are constant and known; geometry can be initialized reliably) and has datasets with ground truth readily available (KITTI Odometry and New Tsukuba Stereo Dataset). Our evaluation shows that noise models which are more adaptable to the varying nature of noise generally perform better.
[ { "version": "v1", "created": "Fri, 1 Jul 2016 15:02:38 GMT" } ]
2016-07-04T00:00:00
[ [ "Alcantarilla", "Pablo F.", "" ], [ "Woodford", "Oliver J.", "" ] ]
TITLE: Noise Models in Feature-based Stereo Visual Odometry ABSTRACT: Feature-based visual structure and motion reconstruction pipelines, common in visual odometry and large-scale reconstruction from photos, use the location of corresponding features in different images to determine the 3D structure of the scene, as well as the camera parameters associated with each image. The noise model, which defines the likelihood of the location of each feature in each image, is a key factor in the accuracy of such pipelines, alongside optimization strategy. Many different noise models have been proposed in the literature; in this paper we investigate the performance of several. We evaluate these models specifically w.r.t. stereo visual odometry, as this task is both simple (camera intrinsics are constant and known; geometry can be initialized reliably) and has datasets with ground truth readily available (KITTI Odometry and New Tsukuba Stereo Dataset). Our evaluation shows that noise models which are more adaptable to the varying nature of noise generally perform better.
1607.00315
Javier Turek Mr.
Eran Treister and Javier S. Turek and Irad Yavneh
A multilevel framework for sparse optimization with application to inverse covariance estimation and logistic regression
To appear on SISC journal
null
null
null
cs.NA math.OC stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Solving l1 regularized optimization problems is common in the fields of computational biology, signal processing and machine learning. Such l1 regularization is utilized to find sparse minimizers of convex functions. A well-known example is the LASSO problem, where the l1 norm regularizes a quadratic function. A multilevel framework is presented for solving such l1 regularized sparse optimization problems efficiently. We take advantage of the expected sparseness of the solution, and create a hierarchy of problems of similar type, which is traversed in order to accelerate the optimization process. This framework is applied for solving two problems: (1) the sparse inverse covariance estimation problem, and (2) l1-regularized logistic regression. In the first problem, the inverse of an unknown covariance matrix of a multivariate normal distribution is estimated, under the assumption that it is sparse. To this end, an l1 regularized log-determinant optimization problem needs to be solved. This task is challenging especially for large-scale datasets, due to time and memory limitations. In the second problem, the l1-regularization is added to the logistic regression classification objective to reduce overfitting to the data and obtain a sparse model. Numerical experiments demonstrate the efficiency of the multilevel framework in accelerating existing iterative solvers for both of these problems.
[ { "version": "v1", "created": "Fri, 1 Jul 2016 16:59:13 GMT" } ]
2016-07-04T00:00:00
[ [ "Treister", "Eran", "" ], [ "Turek", "Javier S.", "" ], [ "Yavneh", "Irad", "" ] ]
TITLE: A multilevel framework for sparse optimization with application to inverse covariance estimation and logistic regression ABSTRACT: Solving l1 regularized optimization problems is common in the fields of computational biology, signal processing and machine learning. Such l1 regularization is utilized to find sparse minimizers of convex functions. A well-known example is the LASSO problem, where the l1 norm regularizes a quadratic function. A multilevel framework is presented for solving such l1 regularized sparse optimization problems efficiently. We take advantage of the expected sparseness of the solution, and create a hierarchy of problems of similar type, which is traversed in order to accelerate the optimization process. This framework is applied for solving two problems: (1) the sparse inverse covariance estimation problem, and (2) l1-regularized logistic regression. In the first problem, the inverse of an unknown covariance matrix of a multivariate normal distribution is estimated, under the assumption that it is sparse. To this end, an l1 regularized log-determinant optimization problem needs to be solved. This task is challenging especially for large-scale datasets, due to time and memory limitations. In the second problem, the l1-regularization is added to the logistic regression classification objective to reduce overfitting to the data and obtain a sparse model. Numerical experiments demonstrate the efficiency of the multilevel framework in accelerating existing iterative solvers for both of these problems.
1510.02795
S{\o}ren Hauberg
S{\o}ren Hauberg, Oren Freifeld, Anders Boesen Lindbo Larsen, John W. Fisher III, Lars Kai Hansen
Dreaming More Data: Class-dependent Distributions over Diffeomorphisms for Learned Data Augmentation
null
Proceedings of the 19th International Conference on Artificial Intelligence and Statistics, pp. 342-350, 2016
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Data augmentation is a key element in training high-dimensional models. In this approach, one synthesizes new observations by applying pre-specified transformations to the original training data; e.g.~new images are formed by rotating old ones. Current augmentation schemes, however, rely on manual specification of the applied transformations, making data augmentation an implicit form of feature engineering. With an eye towards true end-to-end learning, we suggest learning the applied transformations on a per-class basis. Particularly, we align image pairs within each class under the assumption that the spatial transformation between images belongs to a large class of diffeomorphisms. We then learn a class-specific probabilistic generative models of the transformations in a Riemannian submanifold of the Lie group of diffeomorphisms. We demonstrate significant performance improvements in training deep neural nets over manually-specified augmentation schemes. Our code and augmented datasets are available online.
[ { "version": "v1", "created": "Fri, 9 Oct 2015 20:00:47 GMT" }, { "version": "v2", "created": "Thu, 30 Jun 2016 06:12:38 GMT" } ]
2016-07-01T00:00:00
[ [ "Hauberg", "Søren", "" ], [ "Freifeld", "Oren", "" ], [ "Larsen", "Anders Boesen Lindbo", "" ], [ "Fisher", "John W.", "III" ], [ "Hansen", "Lars Kai", "" ] ]
TITLE: Dreaming More Data: Class-dependent Distributions over Diffeomorphisms for Learned Data Augmentation ABSTRACT: Data augmentation is a key element in training high-dimensional models. In this approach, one synthesizes new observations by applying pre-specified transformations to the original training data; e.g.~new images are formed by rotating old ones. Current augmentation schemes, however, rely on manual specification of the applied transformations, making data augmentation an implicit form of feature engineering. With an eye towards true end-to-end learning, we suggest learning the applied transformations on a per-class basis. Particularly, we align image pairs within each class under the assumption that the spatial transformation between images belongs to a large class of diffeomorphisms. We then learn a class-specific probabilistic generative models of the transformations in a Riemannian submanifold of the Lie group of diffeomorphisms. We demonstrate significant performance improvements in training deep neural nets over manually-specified augmentation schemes. Our code and augmented datasets are available online.
1606.09349
Yuzhong Xie
Zhong Ji, Yuzhong Xie, Yanwei Pang, Lei Chen, Zhongfei Zhang
Zero-Shot Learning with Multi-Battery Factor Analysis
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Zero-shot learning (ZSL) extends the conventional image classification technique to a more challenging situation where the test image categories are not seen in the training samples. Most studies on ZSL utilize side information such as attributes or word vectors to bridge the relations between the seen classes and the unseen classes. However, existing approaches on ZSL typically exploit a shared space for each type of side information independently, which cannot make full use of the complementary knowledge of different types of side information. To this end, this paper presents an MBFA-ZSL approach to embed different types of side information as well as the visual feature into one shared space. Specifically, we first develop an algorithm named Multi-Battery Factor Analysis (MBFA) to build a unified semantic space, and then employ multiple types of side information in it to achieve the ZSL. The close-form solution makes MBFA-ZSL simple to implement and efficient to run on large datasets. Extensive experiments on the popular AwA, CUB, and SUN datasets show its significant superiority over the state-of-the-art approaches.
[ { "version": "v1", "created": "Thu, 30 Jun 2016 05:32:37 GMT" } ]
2016-07-01T00:00:00
[ [ "Ji", "Zhong", "" ], [ "Xie", "Yuzhong", "" ], [ "Pang", "Yanwei", "" ], [ "Chen", "Lei", "" ], [ "Zhang", "Zhongfei", "" ] ]
TITLE: Zero-Shot Learning with Multi-Battery Factor Analysis ABSTRACT: Zero-shot learning (ZSL) extends the conventional image classification technique to a more challenging situation where the test image categories are not seen in the training samples. Most studies on ZSL utilize side information such as attributes or word vectors to bridge the relations between the seen classes and the unseen classes. However, existing approaches on ZSL typically exploit a shared space for each type of side information independently, which cannot make full use of the complementary knowledge of different types of side information. To this end, this paper presents an MBFA-ZSL approach to embed different types of side information as well as the visual feature into one shared space. Specifically, we first develop an algorithm named Multi-Battery Factor Analysis (MBFA) to build a unified semantic space, and then employ multiple types of side information in it to achieve the ZSL. The close-form solution makes MBFA-ZSL simple to implement and efficient to run on large datasets. Extensive experiments on the popular AwA, CUB, and SUN datasets show its significant superiority over the state-of-the-art approaches.