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1608.05842
Jason Yu
Jason J. Yu, Adam W. Harley and Konstantinos G. Derpanis
Back to Basics: Unsupervised Learning of Optical Flow via Brightness Constancy and Motion Smoothness
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recently, convolutional networks (convnets) have proven useful for predicting optical flow. Much of this success is predicated on the availability of large datasets that require expensive and involved data acquisition and laborious la- beling. To bypass these challenges, we propose an unsuper- vised approach (i.e., without leveraging groundtruth flow) to train a convnet end-to-end for predicting optical flow be- tween two images. We use a loss function that combines a data term that measures photometric constancy over time with a spatial term that models the expected variation of flow across the image. Together these losses form a proxy measure for losses based on the groundtruth flow. Empiri- cally, we show that a strong convnet baseline trained with the proposed unsupervised approach outperforms the same network trained with supervision on the KITTI dataset.
[ { "version": "v1", "created": "Sat, 20 Aug 2016 15:25:31 GMT" } ]
2016-08-23T00:00:00
[ [ "Yu", "Jason J.", "" ], [ "Harley", "Adam W.", "" ], [ "Derpanis", "Konstantinos G.", "" ] ]
TITLE: Back to Basics: Unsupervised Learning of Optical Flow via Brightness Constancy and Motion Smoothness ABSTRACT: Recently, convolutional networks (convnets) have proven useful for predicting optical flow. Much of this success is predicated on the availability of large datasets that require expensive and involved data acquisition and laborious la- beling. To bypass these challenges, we propose an unsuper- vised approach (i.e., without leveraging groundtruth flow) to train a convnet end-to-end for predicting optical flow be- tween two images. We use a loss function that combines a data term that measures photometric constancy over time with a spatial term that models the expected variation of flow across the image. Together these losses form a proxy measure for losses based on the groundtruth flow. Empiri- cally, we show that a strong convnet baseline trained with the proposed unsupervised approach outperforms the same network trained with supervision on the KITTI dataset.
no_new_dataset
0.950041
1608.06019
Konstantinos Bousmalis
Konstantinos Bousmalis, George Trigeorgis, Nathan Silberman, Dilip Krishnan, Dumitru Erhan
Domain Separation Networks
This work will be presented at NIPS 2016
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The cost of large scale data collection and annotation often makes the application of machine learning algorithms to new tasks or datasets prohibitively expensive. One approach circumventing this cost is training models on synthetic data where annotations are provided automatically. Despite their appeal, such models often fail to generalize from synthetic to real images, necessitating domain adaptation algorithms to manipulate these models before they can be successfully applied. Existing approaches focus either on mapping representations from one domain to the other, or on learning to extract features that are invariant to the domain from which they were extracted. However, by focusing only on creating a mapping or shared representation between the two domains, they ignore the individual characteristics of each domain. We suggest that explicitly modeling what is unique to each domain can improve a model's ability to extract domain-invariant features. Inspired by work on private-shared component analysis, we explicitly learn to extract image representations that are partitioned into two subspaces: one component which is private to each domain and one which is shared across domains. Our model is trained not only to perform the task we care about in the source domain, but also to use the partitioned representation to reconstruct the images from both domains. Our novel architecture results in a model that outperforms the state-of-the-art on a range of unsupervised domain adaptation scenarios and additionally produces visualizations of the private and shared representations enabling interpretation of the domain adaptation process.
[ { "version": "v1", "created": "Mon, 22 Aug 2016 00:12:27 GMT" } ]
2016-08-23T00:00:00
[ [ "Bousmalis", "Konstantinos", "" ], [ "Trigeorgis", "George", "" ], [ "Silberman", "Nathan", "" ], [ "Krishnan", "Dilip", "" ], [ "Erhan", "Dumitru", "" ] ]
TITLE: Domain Separation Networks ABSTRACT: The cost of large scale data collection and annotation often makes the application of machine learning algorithms to new tasks or datasets prohibitively expensive. One approach circumventing this cost is training models on synthetic data where annotations are provided automatically. Despite their appeal, such models often fail to generalize from synthetic to real images, necessitating domain adaptation algorithms to manipulate these models before they can be successfully applied. Existing approaches focus either on mapping representations from one domain to the other, or on learning to extract features that are invariant to the domain from which they were extracted. However, by focusing only on creating a mapping or shared representation between the two domains, they ignore the individual characteristics of each domain. We suggest that explicitly modeling what is unique to each domain can improve a model's ability to extract domain-invariant features. Inspired by work on private-shared component analysis, we explicitly learn to extract image representations that are partitioned into two subspaces: one component which is private to each domain and one which is shared across domains. Our model is trained not only to perform the task we care about in the source domain, but also to use the partitioned representation to reconstruct the images from both domains. Our novel architecture results in a model that outperforms the state-of-the-art on a range of unsupervised domain adaptation scenarios and additionally produces visualizations of the private and shared representations enabling interpretation of the domain adaptation process.
no_new_dataset
0.946101
1608.06048
Ajinkya More
Ajinkya More
Survey of resampling techniques for improving classification performance in unbalanced datasets
null
null
null
null
stat.AP cs.LG stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A number of classification problems need to deal with data imbalance between classes. Often it is desired to have a high recall on the minority class while maintaining a high precision on the majority class. In this paper, we review a number of resampling techniques proposed in literature to handle unbalanced datasets and study their effect on classification performance.
[ { "version": "v1", "created": "Mon, 22 Aug 2016 04:27:28 GMT" } ]
2016-08-23T00:00:00
[ [ "More", "Ajinkya", "" ] ]
TITLE: Survey of resampling techniques for improving classification performance in unbalanced datasets ABSTRACT: A number of classification problems need to deal with data imbalance between classes. Often it is desired to have a high recall on the minority class while maintaining a high precision on the majority class. In this paper, we review a number of resampling techniques proposed in literature to handle unbalanced datasets and study their effect on classification performance.
no_new_dataset
0.951142
1608.06079
Spiros Denaxas
Christiana McMahon and Spiros Denaxas
A novel framework for assessing metadata quality in epidemiological and public health research settings
American Medical Informatics Association (AMIA) Joint Summits on Translational Science 2015
null
null
null
cs.DL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Metadata are critical in epidemiological and public health research. However, a lack of biomedical metadata quality frameworks and limited awareness of the implications of poor quality metadata renders data analyses problematic. In this study, we created and evaluated a novel framework to assess metadata quality of epidemiological and public health research datasets. We performed a literature review and surveyed stakeholders to enhance our understanding of biomedical metadata quality assessment. The review identified 11 studies and nine quality dimensions; none of which were specifically aimed at biomedical metadata. 96 individuals completed the survey; of those who submitted data, most only assessed metadata quality sometimes, and eight did not at all. Our framework has four sections: a) general information; b) tools and technologies; c) usability; and d) management and curation. We evaluated the framework using three test cases and sought expert feedback. The framework can assess biomedical metadata quality systematically and robustly.
[ { "version": "v1", "created": "Mon, 22 Aug 2016 08:27:24 GMT" } ]
2016-08-23T00:00:00
[ [ "McMahon", "Christiana", "" ], [ "Denaxas", "Spiros", "" ] ]
TITLE: A novel framework for assessing metadata quality in epidemiological and public health research settings ABSTRACT: Metadata are critical in epidemiological and public health research. However, a lack of biomedical metadata quality frameworks and limited awareness of the implications of poor quality metadata renders data analyses problematic. In this study, we created and evaluated a novel framework to assess metadata quality of epidemiological and public health research datasets. We performed a literature review and surveyed stakeholders to enhance our understanding of biomedical metadata quality assessment. The review identified 11 studies and nine quality dimensions; none of which were specifically aimed at biomedical metadata. 96 individuals completed the survey; of those who submitted data, most only assessed metadata quality sometimes, and eight did not at all. Our framework has four sections: a) general information; b) tools and technologies; c) usability; and d) management and curation. We evaluated the framework using three test cases and sought expert feedback. The framework can assess biomedical metadata quality systematically and robustly.
no_new_dataset
0.954478
1608.06154
Pankaj Malhotra Mr.
Pankaj Malhotra, Vishnu TV, Anusha Ramakrishnan, Gaurangi Anand, Lovekesh Vig, Puneet Agarwal, Gautam Shroff
Multi-Sensor Prognostics using an Unsupervised Health Index based on LSTM Encoder-Decoder
Presented at 1st ACM SIGKDD Workshop on Machine Learning for Prognostics and Health Management, San Francisco, CA, USA, 2016. 10 pages
null
null
null
cs.LG cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Many approaches for estimation of Remaining Useful Life (RUL) of a machine, using its operational sensor data, make assumptions about how a system degrades or a fault evolves, e.g., exponential degradation. However, in many domains degradation may not follow a pattern. We propose a Long Short Term Memory based Encoder-Decoder (LSTM-ED) scheme to obtain an unsupervised health index (HI) for a system using multi-sensor time-series data. LSTM-ED is trained to reconstruct the time-series corresponding to healthy state of a system. The reconstruction error is used to compute HI which is then used for RUL estimation. We evaluate our approach on publicly available Turbofan Engine and Milling Machine datasets. We also present results on a real-world industry dataset from a pulverizer mill where we find significant correlation between LSTM-ED based HI and maintenance costs.
[ { "version": "v1", "created": "Mon, 22 Aug 2016 12:59:31 GMT" } ]
2016-08-23T00:00:00
[ [ "Malhotra", "Pankaj", "" ], [ "TV", "Vishnu", "" ], [ "Ramakrishnan", "Anusha", "" ], [ "Anand", "Gaurangi", "" ], [ "Vig", "Lovekesh", "" ], [ "Agarwal", "Puneet", "" ], [ "Shroff", "Gautam", "" ] ]
TITLE: Multi-Sensor Prognostics using an Unsupervised Health Index based on LSTM Encoder-Decoder ABSTRACT: Many approaches for estimation of Remaining Useful Life (RUL) of a machine, using its operational sensor data, make assumptions about how a system degrades or a fault evolves, e.g., exponential degradation. However, in many domains degradation may not follow a pattern. We propose a Long Short Term Memory based Encoder-Decoder (LSTM-ED) scheme to obtain an unsupervised health index (HI) for a system using multi-sensor time-series data. LSTM-ED is trained to reconstruct the time-series corresponding to healthy state of a system. The reconstruction error is used to compute HI which is then used for RUL estimation. We evaluate our approach on publicly available Turbofan Engine and Milling Machine datasets. We also present results on a real-world industry dataset from a pulverizer mill where we find significant correlation between LSTM-ED based HI and maintenance costs.
no_new_dataset
0.946794
1608.06192
Alban Desmaison
Alban Desmaison, Rudy Bunel, Pushmeet Kohli, Philip H.S. Torr and M. Pawan Kumar
Efficient Continuous Relaxations for Dense CRF
null
null
null
null
cs.CV
http://creativecommons.org/licenses/by/4.0/
Dense conditional random fields (CRF) with Gaussian pairwise potentials have emerged as a popular framework for several computer vision applications such as stereo correspondence and semantic segmentation. By modeling long-range interactions, dense CRFs provide a more detailed labelling compared to their sparse counterparts. Variational inference in these dense models is performed using a filtering-based mean-field algorithm in order to obtain a fully-factorized distribution minimising the Kullback-Leibler divergence to the true distribution. In contrast to the continuous relaxation-based energy minimisation algorithms used for sparse CRFs, the mean-field algorithm fails to provide strong theoretical guarantees on the quality of its solutions. To address this deficiency, we show that it is possible to use the same filtering approach to speed-up the optimisation of several continuous relaxations. Specifically, we solve a convex quadratic programming (QP) relaxation using the efficient Frank-Wolfe algorithm. This also allows us to solve difference-of-convex relaxations via the iterative concave-convex procedure where each iteration requires solving a convex QP. Finally, we develop a novel divide-and-conquer method to compute the subgradients of a linear programming relaxation that provides the best theoretical bounds for energy minimisation. We demonstrate the advantage of continuous relaxations over the widely used mean-field algorithm on publicly available datasets.
[ { "version": "v1", "created": "Mon, 22 Aug 2016 15:24:25 GMT" } ]
2016-08-23T00:00:00
[ [ "Desmaison", "Alban", "" ], [ "Bunel", "Rudy", "" ], [ "Kohli", "Pushmeet", "" ], [ "Torr", "Philip H. S.", "" ], [ "Kumar", "M. Pawan", "" ] ]
TITLE: Efficient Continuous Relaxations for Dense CRF ABSTRACT: Dense conditional random fields (CRF) with Gaussian pairwise potentials have emerged as a popular framework for several computer vision applications such as stereo correspondence and semantic segmentation. By modeling long-range interactions, dense CRFs provide a more detailed labelling compared to their sparse counterparts. Variational inference in these dense models is performed using a filtering-based mean-field algorithm in order to obtain a fully-factorized distribution minimising the Kullback-Leibler divergence to the true distribution. In contrast to the continuous relaxation-based energy minimisation algorithms used for sparse CRFs, the mean-field algorithm fails to provide strong theoretical guarantees on the quality of its solutions. To address this deficiency, we show that it is possible to use the same filtering approach to speed-up the optimisation of several continuous relaxations. Specifically, we solve a convex quadratic programming (QP) relaxation using the efficient Frank-Wolfe algorithm. This also allows us to solve difference-of-convex relaxations via the iterative concave-convex procedure where each iteration requires solving a convex QP. Finally, we develop a novel divide-and-conquer method to compute the subgradients of a linear programming relaxation that provides the best theoretical bounds for energy minimisation. We demonstrate the advantage of continuous relaxations over the widely used mean-field algorithm on publicly available datasets.
no_new_dataset
0.945751
1608.06197
Srinivas S S Kruthiventi
Lokesh Boominathan, Srinivas S S Kruthiventi and R. Venkatesh Babu
CrowdNet: A Deep Convolutional Network for Dense Crowd Counting
Accepted at ACM Multimedia (MM) 2016
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Our work proposes a novel deep learning framework for estimating crowd density from static images of highly dense crowds. We use a combination of deep and shallow, fully convolutional networks to predict the density map for a given crowd image. Such a combination is used for effectively capturing both the high-level semantic information (face/body detectors) and the low-level features (blob detectors), that are necessary for crowd counting under large scale variations. As most crowd datasets have limited training samples (<100 images) and deep learning based approaches require large amounts of training data, we perform multi-scale data augmentation. Augmenting the training samples in such a manner helps in guiding the CNN to learn scale invariant representations. Our method is tested on the challenging UCF_CC_50 dataset, and shown to outperform the state of the art methods.
[ { "version": "v1", "created": "Mon, 22 Aug 2016 15:43:29 GMT" } ]
2016-08-23T00:00:00
[ [ "Boominathan", "Lokesh", "" ], [ "Kruthiventi", "Srinivas S S", "" ], [ "Babu", "R. Venkatesh", "" ] ]
TITLE: CrowdNet: A Deep Convolutional Network for Dense Crowd Counting ABSTRACT: Our work proposes a novel deep learning framework for estimating crowd density from static images of highly dense crowds. We use a combination of deep and shallow, fully convolutional networks to predict the density map for a given crowd image. Such a combination is used for effectively capturing both the high-level semantic information (face/body detectors) and the low-level features (blob detectors), that are necessary for crowd counting under large scale variations. As most crowd datasets have limited training samples (<100 images) and deep learning based approaches require large amounts of training data, we perform multi-scale data augmentation. Augmenting the training samples in such a manner helps in guiding the CNN to learn scale invariant representations. Our method is tested on the challenging UCF_CC_50 dataset, and shown to outperform the state of the art methods.
no_new_dataset
0.953579
1608.06203
Sewoong Oh
Ashish Khetan, Sewoong Oh
Computational and Statistical Tradeoffs in Learning to Rank
30 pages 5 figures
null
null
null
cs.LG cs.IT math.IT stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
For massive and heterogeneous modern datasets, it is of fundamental interest to provide guarantees on the accuracy of estimation when computational resources are limited. In the application of learning to rank, we provide a hierarchy of rank-breaking mechanisms ordered by the complexity in thus generated sketch of the data. This allows the number of data points collected to be gracefully traded off against computational resources available, while guaranteeing the desired level of accuracy. Theoretical guarantees on the proposed generalized rank-breaking implicitly provide such trade-offs, which can be explicitly characterized under certain canonical scenarios on the structure of the data.
[ { "version": "v1", "created": "Mon, 22 Aug 2016 15:58:31 GMT" } ]
2016-08-23T00:00:00
[ [ "Khetan", "Ashish", "" ], [ "Oh", "Sewoong", "" ] ]
TITLE: Computational and Statistical Tradeoffs in Learning to Rank ABSTRACT: For massive and heterogeneous modern datasets, it is of fundamental interest to provide guarantees on the accuracy of estimation when computational resources are limited. In the application of learning to rank, we provide a hierarchy of rank-breaking mechanisms ordered by the complexity in thus generated sketch of the data. This allows the number of data points collected to be gracefully traded off against computational resources available, while guaranteeing the desired level of accuracy. Theoretical guarantees on the proposed generalized rank-breaking implicitly provide such trade-offs, which can be explicitly characterized under certain canonical scenarios on the structure of the data.
no_new_dataset
0.946349
1608.06253
Christina Lioma Assoc. Prof
Brian Brost and Yevgeny Seldin and Ingemar J. Cox and Christina Lioma
Multi-Dueling Bandits and Their Application to Online Ranker Evaluation
null
null
null
null
cs.IR cs.LG stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
New ranking algorithms are continually being developed and refined, necessitating the development of efficient methods for evaluating these rankers. Online ranker evaluation focuses on the challenge of efficiently determining, from implicit user feedback, which ranker out of a finite set of rankers is the best. Online ranker evaluation can be modeled by dueling ban- dits, a mathematical model for online learning under limited feedback from pairwise comparisons. Comparisons of pairs of rankers is performed by interleaving their result sets and examining which documents users click on. The dueling bandits model addresses the key issue of which pair of rankers to compare at each iteration, thereby providing a solution to the exploration-exploitation trade-off. Recently, methods for simultaneously comparing more than two rankers have been developed. However, the question of which rankers to compare at each iteration was left open. We address this question by proposing a generalization of the dueling bandits model that uses simultaneous comparisons of an unrestricted number of rankers. We evaluate our algorithm on synthetic data and several standard large-scale online ranker evaluation datasets. Our experimental results show that the algorithm yields orders of magnitude improvement in performance compared to stateof- the-art dueling bandit algorithms.
[ { "version": "v1", "created": "Mon, 22 Aug 2016 18:20:18 GMT" } ]
2016-08-23T00:00:00
[ [ "Brost", "Brian", "" ], [ "Seldin", "Yevgeny", "" ], [ "Cox", "Ingemar J.", "" ], [ "Lioma", "Christina", "" ] ]
TITLE: Multi-Dueling Bandits and Their Application to Online Ranker Evaluation ABSTRACT: New ranking algorithms are continually being developed and refined, necessitating the development of efficient methods for evaluating these rankers. Online ranker evaluation focuses on the challenge of efficiently determining, from implicit user feedback, which ranker out of a finite set of rankers is the best. Online ranker evaluation can be modeled by dueling ban- dits, a mathematical model for online learning under limited feedback from pairwise comparisons. Comparisons of pairs of rankers is performed by interleaving their result sets and examining which documents users click on. The dueling bandits model addresses the key issue of which pair of rankers to compare at each iteration, thereby providing a solution to the exploration-exploitation trade-off. Recently, methods for simultaneously comparing more than two rankers have been developed. However, the question of which rankers to compare at each iteration was left open. We address this question by proposing a generalization of the dueling bandits model that uses simultaneous comparisons of an unrestricted number of rankers. We evaluate our algorithm on synthetic data and several standard large-scale online ranker evaluation datasets. Our experimental results show that the algorithm yields orders of magnitude improvement in performance compared to stateof- the-art dueling bandit algorithms.
no_new_dataset
0.949106
1509.02314
Shenjian Zhao
Shenjian Zhao, Cong Xie, Zhihua Zhang
A Scalable and Extensible Framework for Superposition-Structured Models
null
AAAI 2016: 2372-2378
null
null
cs.NA math.OC stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In many learning tasks, structural models usually lead to better interpretability and higher generalization performance. In recent years, however, the simple structural models such as lasso are frequently proved to be insufficient. Accordingly, there has been a lot of work on "superposition-structured" models where multiple structural constraints are imposed. To efficiently solve these "superposition-structured" statistical models, we develop a framework based on a proximal Newton-type method. Employing the smoothed conic dual approach with the LBFGS updating formula, we propose a scalable and extensible proximal quasi-Newton (SEP-QN) framework. Empirical analysis on various datasets shows that our framework is potentially powerful, and achieves super-linear convergence rate for optimizing some popular "superposition-structured" statistical models such as the fused sparse group lasso.
[ { "version": "v1", "created": "Tue, 8 Sep 2015 10:33:27 GMT" }, { "version": "v2", "created": "Tue, 8 Mar 2016 04:29:43 GMT" } ]
2016-08-22T00:00:00
[ [ "Zhao", "Shenjian", "" ], [ "Xie", "Cong", "" ], [ "Zhang", "Zhihua", "" ] ]
TITLE: A Scalable and Extensible Framework for Superposition-Structured Models ABSTRACT: In many learning tasks, structural models usually lead to better interpretability and higher generalization performance. In recent years, however, the simple structural models such as lasso are frequently proved to be insufficient. Accordingly, there has been a lot of work on "superposition-structured" models where multiple structural constraints are imposed. To efficiently solve these "superposition-structured" statistical models, we develop a framework based on a proximal Newton-type method. Employing the smoothed conic dual approach with the LBFGS updating formula, we propose a scalable and extensible proximal quasi-Newton (SEP-QN) framework. Empirical analysis on various datasets shows that our framework is potentially powerful, and achieves super-linear convergence rate for optimizing some popular "superposition-structured" statistical models such as the fused sparse group lasso.
no_new_dataset
0.94743
1511.04512
Ziming Zhang
Ziming Zhang and Venkatesh Saligrama
Zero-Shot Learning via Joint Latent Similarity Embedding
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Zero-shot recognition (ZSR) deals with the problem of predicting class labels for target domain instances based on source domain side information (e.g. attributes) of unseen classes. We formulate ZSR as a binary prediction problem. Our resulting classifier is class-independent. It takes an arbitrary pair of source and target domain instances as input and predicts whether or not they come from the same class, i.e. whether there is a match. We model the posterior probability of a match since it is a sufficient statistic and propose a latent probabilistic model in this context. We develop a joint discriminative learning framework based on dictionary learning to jointly learn the parameters of our model for both domains, which ultimately leads to our class-independent classifier. Many of the existing embedding methods can be viewed as special cases of our probabilistic model. On ZSR our method shows 4.90\% improvement over the state-of-the-art in accuracy averaged across four benchmark datasets. We also adapt ZSR method for zero-shot retrieval and show 22.45\% improvement accordingly in mean average precision (mAP).
[ { "version": "v1", "created": "Sat, 14 Nov 2015 05:53:30 GMT" }, { "version": "v2", "created": "Thu, 21 Apr 2016 22:14:15 GMT" }, { "version": "v3", "created": "Wed, 17 Aug 2016 16:29:51 GMT" } ]
2016-08-22T00:00:00
[ [ "Zhang", "Ziming", "" ], [ "Saligrama", "Venkatesh", "" ] ]
TITLE: Zero-Shot Learning via Joint Latent Similarity Embedding ABSTRACT: Zero-shot recognition (ZSR) deals with the problem of predicting class labels for target domain instances based on source domain side information (e.g. attributes) of unseen classes. We formulate ZSR as a binary prediction problem. Our resulting classifier is class-independent. It takes an arbitrary pair of source and target domain instances as input and predicts whether or not they come from the same class, i.e. whether there is a match. We model the posterior probability of a match since it is a sufficient statistic and propose a latent probabilistic model in this context. We develop a joint discriminative learning framework based on dictionary learning to jointly learn the parameters of our model for both domains, which ultimately leads to our class-independent classifier. Many of the existing embedding methods can be viewed as special cases of our probabilistic model. On ZSR our method shows 4.90\% improvement over the state-of-the-art in accuracy averaged across four benchmark datasets. We also adapt ZSR method for zero-shot retrieval and show 22.45\% improvement accordingly in mean average precision (mAP).
no_new_dataset
0.947381
1601.06759
A\"aron van den Oord
Aaron van den Oord, Nal Kalchbrenner, Koray Kavukcuoglu
Pixel Recurrent Neural Networks
null
null
null
null
cs.CV cs.LG cs.NE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Modeling the distribution of natural images is a landmark problem in unsupervised learning. This task requires an image model that is at once expressive, tractable and scalable. We present a deep neural network that sequentially predicts the pixels in an image along the two spatial dimensions. Our method models the discrete probability of the raw pixel values and encodes the complete set of dependencies in the image. Architectural novelties include fast two-dimensional recurrent layers and an effective use of residual connections in deep recurrent networks. We achieve log-likelihood scores on natural images that are considerably better than the previous state of the art. Our main results also provide benchmarks on the diverse ImageNet dataset. Samples generated from the model appear crisp, varied and globally coherent.
[ { "version": "v1", "created": "Mon, 25 Jan 2016 20:34:24 GMT" }, { "version": "v2", "created": "Mon, 29 Feb 2016 15:32:16 GMT" }, { "version": "v3", "created": "Fri, 19 Aug 2016 14:10:16 GMT" } ]
2016-08-22T00:00:00
[ [ "Oord", "Aaron van den", "" ], [ "Kalchbrenner", "Nal", "" ], [ "Kavukcuoglu", "Koray", "" ] ]
TITLE: Pixel Recurrent Neural Networks ABSTRACT: Modeling the distribution of natural images is a landmark problem in unsupervised learning. This task requires an image model that is at once expressive, tractable and scalable. We present a deep neural network that sequentially predicts the pixels in an image along the two spatial dimensions. Our method models the discrete probability of the raw pixel values and encodes the complete set of dependencies in the image. Architectural novelties include fast two-dimensional recurrent layers and an effective use of residual connections in deep recurrent networks. We achieve log-likelihood scores on natural images that are considerably better than the previous state of the art. Our main results also provide benchmarks on the diverse ImageNet dataset. Samples generated from the model appear crisp, varied and globally coherent.
no_new_dataset
0.948106
1608.05457
Takeshi Onishi
Takeshi Onishi, Hai Wang, Mohit Bansal, Kevin Gimpel and David McAllester
Who did What: A Large-Scale Person-Centered Cloze Dataset
To appear at EMNLP 2016. Our dataset is available at tticnlp.github.io/who_did_what
null
null
null
cs.CL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We have constructed a new "Who-did-What" dataset of over 200,000 fill-in-the-gap (cloze) multiple choice reading comprehension problems constructed from the LDC English Gigaword newswire corpus. The WDW dataset has a variety of novel features. First, in contrast with the CNN and Daily Mail datasets (Hermann et al., 2015) we avoid using article summaries for question formation. Instead, each problem is formed from two independent articles --- an article given as the passage to be read and a separate article on the same events used to form the question. Second, we avoid anonymization --- each choice is a person named entity. Third, the problems have been filtered to remove a fraction that are easily solved by simple baselines, while remaining 84% solvable by humans. We report performance benchmarks of standard systems and propose the WDW dataset as a challenge task for the community.
[ { "version": "v1", "created": "Fri, 19 Aug 2016 00:13:10 GMT" } ]
2016-08-22T00:00:00
[ [ "Onishi", "Takeshi", "" ], [ "Wang", "Hai", "" ], [ "Bansal", "Mohit", "" ], [ "Gimpel", "Kevin", "" ], [ "McAllester", "David", "" ] ]
TITLE: Who did What: A Large-Scale Person-Centered Cloze Dataset ABSTRACT: We have constructed a new "Who-did-What" dataset of over 200,000 fill-in-the-gap (cloze) multiple choice reading comprehension problems constructed from the LDC English Gigaword newswire corpus. The WDW dataset has a variety of novel features. First, in contrast with the CNN and Daily Mail datasets (Hermann et al., 2015) we avoid using article summaries for question formation. Instead, each problem is formed from two independent articles --- an article given as the passage to be read and a separate article on the same events used to form the question. Second, we avoid anonymization --- each choice is a person named entity. Third, the problems have been filtered to remove a fraction that are easily solved by simple baselines, while remaining 84% solvable by humans. We report performance benchmarks of standard systems and propose the WDW dataset as a challenge task for the community.
new_dataset
0.957794
1608.05562
Enzo Ferrante
Roque Porchetto (1), Franco Stramana (1), Nikos Paragios (2), Enzo Ferrante (2) ((1) UNICEN University, Tandil Argentina, (2) CVN, CentraleSupelec-INRIA, Universite Paris-Saclay, France)
Rigid Slice-To-Volume Medical Image Registration through Markov Random Fields
Bayesian and Graphical Models for Biomedical Imaging Workshop, BAMBI (MICCAI 2016, Athens, Greece)
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Rigid slice-to-volume registration is a challenging task, which finds application in medical imaging problems like image fusion for image guided surgeries and motion correction for volume reconstruction. It is usually formulated as an optimization problem and solved using standard continuous methods. In this paper, we discuss how this task be formulated as a discrete labeling problem on a graph. Inspired by previous works on discrete estimation of linear transformations using Markov Random Fields (MRFs), we model it using a pairwise MRF, where the nodes are associated to the rigid parameters, and the edges encode the relation between the variables. We compare the performance of the proposed method to a continuous formulation optimized using simplex, and we discuss how it can be used to further improve the accuracy of our approach. Promising results are obtained using a monomodal dataset composed of magnetic resonance images (MRI) of a beating heart.
[ { "version": "v1", "created": "Fri, 19 Aug 2016 10:29:50 GMT" } ]
2016-08-22T00:00:00
[ [ "Porchetto", "Roque", "" ], [ "Stramana", "Franco", "" ], [ "Paragios", "Nikos", "" ], [ "Ferrante", "Enzo", "" ] ]
TITLE: Rigid Slice-To-Volume Medical Image Registration through Markov Random Fields ABSTRACT: Rigid slice-to-volume registration is a challenging task, which finds application in medical imaging problems like image fusion for image guided surgeries and motion correction for volume reconstruction. It is usually formulated as an optimization problem and solved using standard continuous methods. In this paper, we discuss how this task be formulated as a discrete labeling problem on a graph. Inspired by previous works on discrete estimation of linear transformations using Markov Random Fields (MRFs), we model it using a pairwise MRF, where the nodes are associated to the rigid parameters, and the edges encode the relation between the variables. We compare the performance of the proposed method to a continuous formulation optimized using simplex, and we discuss how it can be used to further improve the accuracy of our approach. Promising results are obtained using a monomodal dataset composed of magnetic resonance images (MRI) of a beating heart.
new_dataset
0.917414
1608.05605
St\'ephan Tulkens
St\'ephan Tulkens and Simon \v{S}uster and Walter Daelemans
Using Distributed Representations to Disambiguate Biomedical and Clinical Concepts
6 pages, 1 figure, presented at the 15th Workshop on Biomedical Natural Language Processing, Berlin 2016
Proceedings of the 15th Workshop on Biomedical Natural Language Processing, Berlin, Germany, 2016, pages 77-82. Association for Computational Linguistics
null
null
cs.CL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we report a knowledge-based method for Word Sense Disambiguation in the domains of biomedical and clinical text. We combine word representations created on large corpora with a small number of definitions from the UMLS to create concept representations, which we then compare to representations of the context of ambiguous terms. Using no relational information, we obtain comparable performance to previous approaches on the MSH-WSD dataset, which is a well-known dataset in the biomedical domain. Additionally, our method is fast and easy to set up and extend to other domains. Supplementary materials, including source code, can be found at https: //github.com/clips/yarn
[ { "version": "v1", "created": "Fri, 19 Aug 2016 14:05:03 GMT" } ]
2016-08-22T00:00:00
[ [ "Tulkens", "Stéphan", "" ], [ "Šuster", "Simon", "" ], [ "Daelemans", "Walter", "" ] ]
TITLE: Using Distributed Representations to Disambiguate Biomedical and Clinical Concepts ABSTRACT: In this paper, we report a knowledge-based method for Word Sense Disambiguation in the domains of biomedical and clinical text. We combine word representations created on large corpora with a small number of definitions from the UMLS to create concept representations, which we then compare to representations of the context of ambiguous terms. Using no relational information, we obtain comparable performance to previous approaches on the MSH-WSD dataset, which is a well-known dataset in the biomedical domain. Additionally, our method is fast and easy to set up and extend to other domains. Supplementary materials, including source code, can be found at https: //github.com/clips/yarn
no_new_dataset
0.948489
1608.05684
Menghua Zhai
Menghua Zhai, Scott Workman, Nathan Jacobs
Detecting Vanishing Points using Global Image Context in a Non-Manhattan World
IEEE Conference on Computer Vision and Pattern Recognition (CVPR) 2016
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a novel method for detecting horizontal vanishing points and the zenith vanishing point in man-made environments. The dominant trend in existing methods is to first find candidate vanishing points, then remove outliers by enforcing mutual orthogonality. Our method reverses this process: we propose a set of horizon line candidates and score each based on the vanishing points it contains. A key element of our approach is the use of global image context, extracted with a deep convolutional network, to constrain the set of candidates under consideration. Our method does not make a Manhattan-world assumption and can operate effectively on scenes with only a single horizontal vanishing point. We evaluate our approach on three benchmark datasets and achieve state-of-the-art performance on each. In addition, our approach is significantly faster than the previous best method.
[ { "version": "v1", "created": "Fri, 19 Aug 2016 18:08:55 GMT" } ]
2016-08-22T00:00:00
[ [ "Zhai", "Menghua", "" ], [ "Workman", "Scott", "" ], [ "Jacobs", "Nathan", "" ] ]
TITLE: Detecting Vanishing Points using Global Image Context in a Non-Manhattan World ABSTRACT: We propose a novel method for detecting horizontal vanishing points and the zenith vanishing point in man-made environments. The dominant trend in existing methods is to first find candidate vanishing points, then remove outliers by enforcing mutual orthogonality. Our method reverses this process: we propose a set of horizon line candidates and score each based on the vanishing points it contains. A key element of our approach is the use of global image context, extracted with a deep convolutional network, to constrain the set of candidates under consideration. Our method does not make a Manhattan-world assumption and can operate effectively on scenes with only a single horizontal vanishing point. We evaluate our approach on three benchmark datasets and achieve state-of-the-art performance on each. In addition, our approach is significantly faster than the previous best method.
no_new_dataset
0.950824
1608.05104
Nasim Souly
Nasim Souly and Mubarak Shah
Scene Labeling Through Knowledge-Based Rules Employing Constrained Integer Linear Programing
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Scene labeling task is to segment the image into meaningful regions and categorize them into classes of objects which comprised the image. Commonly used methods typically find the local features for each segment and label them using classifiers. Afterward, labeling is smoothed in order to make sure that neighboring regions receive similar labels. However, they ignore expressive and non-local dependencies among regions due to expensive training and inference. In this paper, we propose to use high-level knowledge regarding rules in the inference to incorporate dependencies among regions in the image to improve scores of classification. Towards this aim, we extract these rules from data and transform them into constraints for Integer Programming to optimize the structured problem of assigning labels to super-pixels (consequently pixels) of an image. In addition, we propose to use soft-constraints in some scenarios, allowing violating the constraint by imposing a penalty, to make the model more flexible. We assessed our approach on three datasets and obtained promising results.
[ { "version": "v1", "created": "Wed, 17 Aug 2016 21:14:51 GMT" } ]
2016-08-19T00:00:00
[ [ "Souly", "Nasim", "" ], [ "Shah", "Mubarak", "" ] ]
TITLE: Scene Labeling Through Knowledge-Based Rules Employing Constrained Integer Linear Programing ABSTRACT: Scene labeling task is to segment the image into meaningful regions and categorize them into classes of objects which comprised the image. Commonly used methods typically find the local features for each segment and label them using classifiers. Afterward, labeling is smoothed in order to make sure that neighboring regions receive similar labels. However, they ignore expressive and non-local dependencies among regions due to expensive training and inference. In this paper, we propose to use high-level knowledge regarding rules in the inference to incorporate dependencies among regions in the image to improve scores of classification. Towards this aim, we extract these rules from data and transform them into constraints for Integer Programming to optimize the structured problem of assigning labels to super-pixels (consequently pixels) of an image. In addition, we propose to use soft-constraints in some scenarios, allowing violating the constraint by imposing a penalty, to make the model more flexible. We assessed our approach on three datasets and obtained promising results.
no_new_dataset
0.947478
1608.05117
Saeed Mohajeryami
Saeed Mohajeryami
An Investigation of Randomized Controlled Trial (RCT) Method as a Customer Baseline Load (CBL) Calculation for Residential Customers
null
null
null
null
cs.SY
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
FERC Order 745 allows demand response owners to sell their load reduction in the wholesale market. However, in order to be able to sell the load reduction, some implementation challenges must be addressed, one of which is to establish Customer Baseline Load (CBL) calculation methods with acceptable error performance, which has proven to be very challenging so far. In this paper, the error and financial performance of Randomized Controlled Trial (RCT) method, applied to both granular and aggregated forms of the consumption load, are investigated for a hypothetical demand response program offered to a real dataset of residential customers .
[ { "version": "v1", "created": "Wed, 17 Aug 2016 22:16:26 GMT" } ]
2016-08-19T00:00:00
[ [ "Mohajeryami", "Saeed", "" ] ]
TITLE: An Investigation of Randomized Controlled Trial (RCT) Method as a Customer Baseline Load (CBL) Calculation for Residential Customers ABSTRACT: FERC Order 745 allows demand response owners to sell their load reduction in the wholesale market. However, in order to be able to sell the load reduction, some implementation challenges must be addressed, one of which is to establish Customer Baseline Load (CBL) calculation methods with acceptable error performance, which has proven to be very challenging so far. In this paper, the error and financial performance of Randomized Controlled Trial (RCT) method, applied to both granular and aggregated forms of the consumption load, are investigated for a hypothetical demand response program offered to a real dataset of residential customers .
no_new_dataset
0.94625
1608.05159
Jianan Li
Jianan Li, Xiaodan Liang, Jianshu Li, Tingfa Xu, Jiashi Feng, Shuicheng Yan
Multi-stage Object Detection with Group Recursive Learning
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Most of existing detection pipelines treat object proposals independently and predict bounding box locations and classification scores over them separately. However, the important semantic and spatial layout correlations among proposals are often ignored, which are actually useful for more accurate object detection. In this work, we propose a new EM-like group recursive learning approach to iteratively refine object proposals by incorporating such context of surrounding proposals and provide an optimal spatial configuration of object detections. In addition, we propose to incorporate the weakly-supervised object segmentation cues and region-based object detection into a multi-stage architecture in order to fully exploit the learned segmentation features for better object detection in an end-to-end way. The proposed architecture consists of three cascaded networks which respectively learn to perform weakly-supervised object segmentation, object proposal generation and recursive detection refinement. Combining the group recursive learning and the multi-stage architecture provides competitive mAPs of 78.6% and 74.9% on the PASCAL VOC2007 and VOC2012 datasets respectively, which outperforms many well-established baselines [10] [20] significantly.
[ { "version": "v1", "created": "Thu, 18 Aug 2016 02:37:28 GMT" } ]
2016-08-19T00:00:00
[ [ "Li", "Jianan", "" ], [ "Liang", "Xiaodan", "" ], [ "Li", "Jianshu", "" ], [ "Xu", "Tingfa", "" ], [ "Feng", "Jiashi", "" ], [ "Yan", "Shuicheng", "" ] ]
TITLE: Multi-stage Object Detection with Group Recursive Learning ABSTRACT: Most of existing detection pipelines treat object proposals independently and predict bounding box locations and classification scores over them separately. However, the important semantic and spatial layout correlations among proposals are often ignored, which are actually useful for more accurate object detection. In this work, we propose a new EM-like group recursive learning approach to iteratively refine object proposals by incorporating such context of surrounding proposals and provide an optimal spatial configuration of object detections. In addition, we propose to incorporate the weakly-supervised object segmentation cues and region-based object detection into a multi-stage architecture in order to fully exploit the learned segmentation features for better object detection in an end-to-end way. The proposed architecture consists of three cascaded networks which respectively learn to perform weakly-supervised object segmentation, object proposal generation and recursive detection refinement. Combining the group recursive learning and the multi-stage architecture provides competitive mAPs of 78.6% and 74.9% on the PASCAL VOC2007 and VOC2012 datasets respectively, which outperforms many well-established baselines [10] [20] significantly.
no_new_dataset
0.947575
1608.05174
Cory James Kleinheksel
Cory J. Kleinheksel and Arun K. Somani
Scaling Distributed All-Pairs Algorithms: Manage Computation and Limit Data Replication with Quorums
Chapter Information Science and Applications (ICISA) 2016 Volume 376 of the series Lecture Notes in Electrical Engineering pp 247-257 Date: 16 February 2016
Kleinheksel, Cory J., and Arun K. Somani. "Scaling Distributed All-Pairs Algorithms." Information Science and Applications (ICISA) 2016. Springer Singapore, 2016. 247-257
10.1007/978-981-10-0557-2_25
null
cs.DC
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we propose and prove that cyclic quorum sets can efficiently manage all-pairs computations and data replication. The quorums are O(N/sqrt(P)) in size, up to 50% smaller than the dual N/sqrt(P) array implementations, and significantly smaller than solutions requiring all data. Implementation evaluation demonstrated scalability on real datasets with a 7x speed up on 8 nodes with 1/3rd the memory usage per process. The all-pairs problem requires all data elements to be paired with all other data elements. These all-pair problems occur in many science fields, which has led to their continued interest. Additionally, as datasets grow in size, new methods like these that can reduce memory footprints and distribute work equally across compute nodes will be demanded.
[ { "version": "v1", "created": "Thu, 18 Aug 2016 04:51:38 GMT" } ]
2016-08-19T00:00:00
[ [ "Kleinheksel", "Cory J.", "" ], [ "Somani", "Arun K.", "" ] ]
TITLE: Scaling Distributed All-Pairs Algorithms: Manage Computation and Limit Data Replication with Quorums ABSTRACT: In this paper we propose and prove that cyclic quorum sets can efficiently manage all-pairs computations and data replication. The quorums are O(N/sqrt(P)) in size, up to 50% smaller than the dual N/sqrt(P) array implementations, and significantly smaller than solutions requiring all data. Implementation evaluation demonstrated scalability on real datasets with a 7x speed up on 8 nodes with 1/3rd the memory usage per process. The all-pairs problem requires all data elements to be paired with all other data elements. These all-pair problems occur in many science fields, which has led to their continued interest. Additionally, as datasets grow in size, new methods like these that can reduce memory footprints and distribute work equally across compute nodes will be demanded.
no_new_dataset
0.944074
1608.05177
Youbao Tang
Youbao Tang, Xiangqian Wu, and Wei Bu
Deeply-Supervised Recurrent Convolutional Neural Network for Saliency Detection
5 pages, 5 figures, accepted by ACMMM 2016
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper proposes a novel saliency detection method by developing a deeply-supervised recurrent convolutional neural network (DSRCNN), which performs a full image-to-image saliency prediction. For saliency detection, the local, global, and contextual information of salient objects is important to obtain a high quality salient map. To achieve this goal, the DSRCNN is designed based on VGGNet-16. Firstly, the recurrent connections are incorporated into each convolutional layer, which can make the model more powerful for learning the contextual information. Secondly, side-output layers are added to conduct the deeply-supervised operation, which can make the model learn more discriminative and robust features by effecting the intermediate layers. Finally, all of the side-outputs are fused to integrate the local and global information to get the final saliency detection results. Therefore, the DSRCNN combines the advantages of recurrent convolutional neural networks and deeply-supervised nets. The DSRCNN model is tested on five benchmark datasets, and experimental results demonstrate that the proposed method significantly outperforms the state-of-the-art saliency detection approaches on all test datasets.
[ { "version": "v1", "created": "Thu, 18 Aug 2016 05:08:16 GMT" } ]
2016-08-19T00:00:00
[ [ "Tang", "Youbao", "" ], [ "Wu", "Xiangqian", "" ], [ "Bu", "Wei", "" ] ]
TITLE: Deeply-Supervised Recurrent Convolutional Neural Network for Saliency Detection ABSTRACT: This paper proposes a novel saliency detection method by developing a deeply-supervised recurrent convolutional neural network (DSRCNN), which performs a full image-to-image saliency prediction. For saliency detection, the local, global, and contextual information of salient objects is important to obtain a high quality salient map. To achieve this goal, the DSRCNN is designed based on VGGNet-16. Firstly, the recurrent connections are incorporated into each convolutional layer, which can make the model more powerful for learning the contextual information. Secondly, side-output layers are added to conduct the deeply-supervised operation, which can make the model learn more discriminative and robust features by effecting the intermediate layers. Finally, all of the side-outputs are fused to integrate the local and global information to get the final saliency detection results. Therefore, the DSRCNN combines the advantages of recurrent convolutional neural networks and deeply-supervised nets. The DSRCNN model is tested on five benchmark datasets, and experimental results demonstrate that the proposed method significantly outperforms the state-of-the-art saliency detection approaches on all test datasets.
no_new_dataset
0.948106
1608.05186
Youbao Tang
Youbao Tang, Xiangqian Wu
Saliency Detection via Combining Region-Level and Pixel-Level Predictions with CNNs
18 pages, 9 figures, accepted by ECCV 2016
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper proposes a novel saliency detection method by combining region-level saliency estimation and pixel-level saliency prediction with CNNs (denoted as CRPSD). For pixel-level saliency prediction, a fully convolutional neural network (called pixel-level CNN) is constructed by modifying the VGGNet architecture to perform multi-scale feature learning, based on which an image-to-image prediction is conducted to accomplish the pixel-level saliency detection. For region-level saliency estimation, an adaptive superpixel based region generation technique is first designed to partition an image into regions, based on which the region-level saliency is estimated by using a CNN model (called region-level CNN). The pixel-level and region-level saliencies are fused to form the final salient map by using another CNN (called fusion CNN). And the pixel-level CNN and fusion CNN are jointly learned. Extensive quantitative and qualitative experiments on four public benchmark datasets demonstrate that the proposed method greatly outperforms the state-of-the-art saliency detection approaches.
[ { "version": "v1", "created": "Thu, 18 Aug 2016 06:00:18 GMT" } ]
2016-08-19T00:00:00
[ [ "Tang", "Youbao", "" ], [ "Wu", "Xiangqian", "" ] ]
TITLE: Saliency Detection via Combining Region-Level and Pixel-Level Predictions with CNNs ABSTRACT: This paper proposes a novel saliency detection method by combining region-level saliency estimation and pixel-level saliency prediction with CNNs (denoted as CRPSD). For pixel-level saliency prediction, a fully convolutional neural network (called pixel-level CNN) is constructed by modifying the VGGNet architecture to perform multi-scale feature learning, based on which an image-to-image prediction is conducted to accomplish the pixel-level saliency detection. For region-level saliency estimation, an adaptive superpixel based region generation technique is first designed to partition an image into regions, based on which the region-level saliency is estimated by using a CNN model (called region-level CNN). The pixel-level and region-level saliencies are fused to form the final salient map by using another CNN (called fusion CNN). And the pixel-level CNN and fusion CNN are jointly learned. Extensive quantitative and qualitative experiments on four public benchmark datasets demonstrate that the proposed method greatly outperforms the state-of-the-art saliency detection approaches.
no_new_dataset
0.951006
1608.05203
Yusuke Sugano
Yusuke Sugano, Andreas Bulling
Seeing with Humans: Gaze-Assisted Neural Image Captioning
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Gaze reflects how humans process visual scenes and is therefore increasingly used in computer vision systems. Previous works demonstrated the potential of gaze for object-centric tasks, such as object localization and recognition, but it remains unclear if gaze can also be beneficial for scene-centric tasks, such as image captioning. We present a new perspective on gaze-assisted image captioning by studying the interplay between human gaze and the attention mechanism of deep neural networks. Using a public large-scale gaze dataset, we first assess the relationship between state-of-the-art object and scene recognition models, bottom-up visual saliency, and human gaze. We then propose a novel split attention model for image captioning. Our model integrates human gaze information into an attention-based long short-term memory architecture, and allows the algorithm to allocate attention selectively to both fixated and non-fixated image regions. Through evaluation on the COCO/SALICON datasets we show that our method improves image captioning performance and that gaze can complement machine attention for semantic scene understanding tasks.
[ { "version": "v1", "created": "Thu, 18 Aug 2016 08:13:22 GMT" } ]
2016-08-19T00:00:00
[ [ "Sugano", "Yusuke", "" ], [ "Bulling", "Andreas", "" ] ]
TITLE: Seeing with Humans: Gaze-Assisted Neural Image Captioning ABSTRACT: Gaze reflects how humans process visual scenes and is therefore increasingly used in computer vision systems. Previous works demonstrated the potential of gaze for object-centric tasks, such as object localization and recognition, but it remains unclear if gaze can also be beneficial for scene-centric tasks, such as image captioning. We present a new perspective on gaze-assisted image captioning by studying the interplay between human gaze and the attention mechanism of deep neural networks. Using a public large-scale gaze dataset, we first assess the relationship between state-of-the-art object and scene recognition models, bottom-up visual saliency, and human gaze. We then propose a novel split attention model for image captioning. Our model integrates human gaze information into an attention-based long short-term memory architecture, and allows the algorithm to allocate attention selectively to both fixated and non-fixated image regions. Through evaluation on the COCO/SALICON datasets we show that our method improves image captioning performance and that gaze can complement machine attention for semantic scene understanding tasks.
no_new_dataset
0.947624
1608.05209
Felix J\"aremo Lawin
Felix J\"aremo Lawin, Per-Erik Forss\'en and Hannes Ovr\'en
Efficient Multi-Frequency Phase Unwrapping using Kernel Density Estimation
Accepted at ECCV 2016
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we introduce an efficient method to unwrap multi-frequency phase estimates for time-of-flight ranging. The algorithm generates multiple depth hypotheses and uses a spatial kernel density estimate (KDE) to rank them. The confidence produced by the KDE is also an effective means to detect outliers. We also introduce a new closed-form expression for phase noise prediction, that better fits real data. The method is applied to depth decoding for the Kinect v2 sensor, and compared to the Microsoft Kinect SDK and to the open source driver libfreenect2. The intended Kinect v2 use case is scenes with less than 8m range, and for such cases we observe consistent improvements, while maintaining real-time performance. When extending the depth range to the maximal value of 8.75m, we get about 52% more valid measurements than libfreenect2. The effect is that the sensor can now be used in large depth scenes, where it was previously not a good choice. Code and supplementary material are available at http://www.cvl.isy.liu.se/research/datasets/kinect2-dataset.
[ { "version": "v1", "created": "Thu, 18 Aug 2016 08:49:13 GMT" } ]
2016-08-19T00:00:00
[ [ "Lawin", "Felix Järemo", "" ], [ "Forssén", "Per-Erik", "" ], [ "Ovrén", "Hannes", "" ] ]
TITLE: Efficient Multi-Frequency Phase Unwrapping using Kernel Density Estimation ABSTRACT: In this paper we introduce an efficient method to unwrap multi-frequency phase estimates for time-of-flight ranging. The algorithm generates multiple depth hypotheses and uses a spatial kernel density estimate (KDE) to rank them. The confidence produced by the KDE is also an effective means to detect outliers. We also introduce a new closed-form expression for phase noise prediction, that better fits real data. The method is applied to depth decoding for the Kinect v2 sensor, and compared to the Microsoft Kinect SDK and to the open source driver libfreenect2. The intended Kinect v2 use case is scenes with less than 8m range, and for such cases we observe consistent improvements, while maintaining real-time performance. When extending the depth range to the maximal value of 8.75m, we get about 52% more valid measurements than libfreenect2. The effect is that the sensor can now be used in large depth scenes, where it was previously not a good choice. Code and supplementary material are available at http://www.cvl.isy.liu.se/research/datasets/kinect2-dataset.
no_new_dataset
0.940079
1608.05266
Juste Raimbault
Juste Raimbault
Investigating the Empirical Existence of Static User Equilibrium
9 pages, 5 figures. Forthcoming in Transportation Research Procedia, EWGT2016, 5-7 September 2016, Istanbul
null
null
null
physics.soc-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Static User Equilibrium is a powerful framework for the theoretical study of traffic. Despite the restricting assumption of stationary flows that intuitively limit its application to real traffic systems, many operational models implementing it are still used without an empirical validation of the existence of the equilibrium. We investigate its existence on a traffic dataset of three months for the region of Paris, FR. The implementation of an application for interactive spatio-temporal data exploration allows to hypothesize a high spatial and temporal heterogeneity, and to guide further quantitative work. The assumption of locally stationary flows is invalidated in a first approximation by empirical results, as shown by a strong spatial and temporal variability in shortest paths and in network topological measures such as betweenness centrality. Furthermore, the behavior of spatial autocorrelation index of congestion patterns at different spatial ranges suggest a chaotic evolution at the local scale, especially during peak hours. We finally discuss the implications of these empirical findings and describe further possible developments based on the estimation of Lyapunov dynamical stability of traffic flows.
[ { "version": "v1", "created": "Thu, 18 Aug 2016 14:02:44 GMT" } ]
2016-08-19T00:00:00
[ [ "Raimbault", "Juste", "" ] ]
TITLE: Investigating the Empirical Existence of Static User Equilibrium ABSTRACT: The Static User Equilibrium is a powerful framework for the theoretical study of traffic. Despite the restricting assumption of stationary flows that intuitively limit its application to real traffic systems, many operational models implementing it are still used without an empirical validation of the existence of the equilibrium. We investigate its existence on a traffic dataset of three months for the region of Paris, FR. The implementation of an application for interactive spatio-temporal data exploration allows to hypothesize a high spatial and temporal heterogeneity, and to guide further quantitative work. The assumption of locally stationary flows is invalidated in a first approximation by empirical results, as shown by a strong spatial and temporal variability in shortest paths and in network topological measures such as betweenness centrality. Furthermore, the behavior of spatial autocorrelation index of congestion patterns at different spatial ranges suggest a chaotic evolution at the local scale, especially during peak hours. We finally discuss the implications of these empirical findings and describe further possible developments based on the estimation of Lyapunov dynamical stability of traffic flows.
no_new_dataset
0.945197
1608.05275
Elad Mezuman
Elad Mezuman and Yair Weiss
A Tight Convex Upper Bound on the Likelihood of a Finite Mixture
icpr 2016
null
null
null
cs.LG stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The likelihood function of a finite mixture model is a non-convex function with multiple local maxima and commonly used iterative algorithms such as EM will converge to different solutions depending on initial conditions. In this paper we ask: is it possible to assess how far we are from the global maximum of the likelihood? Since the likelihood of a finite mixture model can grow unboundedly by centering a Gaussian on a single datapoint and shrinking the covariance, we constrain the problem by assuming that the parameters of the individual models are members of a large discrete set (e.g. estimating a mixture of two Gaussians where the means and variances of both Gaussians are members of a set of a million possible means and variances). For this setting we show that a simple upper bound on the likelihood can be computed using convex optimization and we analyze conditions under which the bound is guaranteed to be tight. This bound can then be used to assess the quality of solutions found by EM (where the final result is projected on the discrete set) or any other mixture estimation algorithm. For any dataset our method allows us to find a finite mixture model together with a dataset-specific bound on how far the likelihood of this mixture is from the global optimum of the likelihood
[ { "version": "v1", "created": "Thu, 18 Aug 2016 14:27:45 GMT" } ]
2016-08-19T00:00:00
[ [ "Mezuman", "Elad", "" ], [ "Weiss", "Yair", "" ] ]
TITLE: A Tight Convex Upper Bound on the Likelihood of a Finite Mixture ABSTRACT: The likelihood function of a finite mixture model is a non-convex function with multiple local maxima and commonly used iterative algorithms such as EM will converge to different solutions depending on initial conditions. In this paper we ask: is it possible to assess how far we are from the global maximum of the likelihood? Since the likelihood of a finite mixture model can grow unboundedly by centering a Gaussian on a single datapoint and shrinking the covariance, we constrain the problem by assuming that the parameters of the individual models are members of a large discrete set (e.g. estimating a mixture of two Gaussians where the means and variances of both Gaussians are members of a set of a million possible means and variances). For this setting we show that a simple upper bound on the likelihood can be computed using convex optimization and we analyze conditions under which the bound is guaranteed to be tight. This bound can then be used to assess the quality of solutions found by EM (where the final result is projected on the discrete set) or any other mixture estimation algorithm. For any dataset our method allows us to find a finite mixture model together with a dataset-specific bound on how far the likelihood of this mixture is from the global optimum of the likelihood
no_new_dataset
0.942454
1608.05346
Zaiqiao Meng
Zaiqiao Meng and Hong Shen
Diversified Top-k Similarity Search in Large Attributed Networks
9 pages, 4 figures, conference
null
null
null
cs.IR
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Given a large network and a query node, finding its top-k similar nodes is a primitive operation in many graph-based applications. Recently enhancing search results with diversification have received much attention. In this paper, we explore an novel problem of searching for top-k diversified similar nodes in attributed networks, with the motivation that modeling diversification in an attributed network should consider both the emergence of network links and the attribute features of nodes such as user profile information. We formulate this practical problem as two optimization problems: the Attributed Coverage Diversification (ACD) problem and the r-Dissimilar Attributed Coverage Diversification (r-DACD) problem. Based on the submodularity and the monotonicity of ACD, we propose an efficient greedy algorithm achieving a tight approximation guarantee of 1-1/e. Unlike the expension based methods only considering nodes' neighborhood, ACD generalize the definition of diversification to nodes' own features. To capture diversification in topological structure of networks, the r-DACD problem introduce a dissimilarity constraint. We refer to this problem as the Dissimilarity Constrained Non-monotone Submodular Maximization (DCNSM) problem. We prove that there is no constant-factor approximation for DCNSM, and also present an efficient greedy algorithms achieving $1/\rho$ approximation, where $\rho\le\Delta$, $\Delta$ is the maximum degree of its dissimilarity based graph. To the best of our knowledge, it is the first approximation algorithm for the Submodular Maximization problem with a distance constraint. The experimental results on real-world attributed network datasets demonstrate the effectiveness of our methods, and confirm that adding dissimilarity constraint can significantly enhance the performance of diversification.
[ { "version": "v1", "created": "Thu, 18 Aug 2016 17:45:45 GMT" } ]
2016-08-19T00:00:00
[ [ "Meng", "Zaiqiao", "" ], [ "Shen", "Hong", "" ] ]
TITLE: Diversified Top-k Similarity Search in Large Attributed Networks ABSTRACT: Given a large network and a query node, finding its top-k similar nodes is a primitive operation in many graph-based applications. Recently enhancing search results with diversification have received much attention. In this paper, we explore an novel problem of searching for top-k diversified similar nodes in attributed networks, with the motivation that modeling diversification in an attributed network should consider both the emergence of network links and the attribute features of nodes such as user profile information. We formulate this practical problem as two optimization problems: the Attributed Coverage Diversification (ACD) problem and the r-Dissimilar Attributed Coverage Diversification (r-DACD) problem. Based on the submodularity and the monotonicity of ACD, we propose an efficient greedy algorithm achieving a tight approximation guarantee of 1-1/e. Unlike the expension based methods only considering nodes' neighborhood, ACD generalize the definition of diversification to nodes' own features. To capture diversification in topological structure of networks, the r-DACD problem introduce a dissimilarity constraint. We refer to this problem as the Dissimilarity Constrained Non-monotone Submodular Maximization (DCNSM) problem. We prove that there is no constant-factor approximation for DCNSM, and also present an efficient greedy algorithms achieving $1/\rho$ approximation, where $\rho\le\Delta$, $\Delta$ is the maximum degree of its dissimilarity based graph. To the best of our knowledge, it is the first approximation algorithm for the Submodular Maximization problem with a distance constraint. The experimental results on real-world attributed network datasets demonstrate the effectiveness of our methods, and confirm that adding dissimilarity constraint can significantly enhance the performance of diversification.
no_new_dataset
0.950869
1608.05374
Srikanth Ronanki
Srikanth Ronanki and Siva Reddy and Bajibabu Bollepalli and Simon King
DNN-based Speech Synthesis for Indian Languages from ASCII text
6 pages, 5 figures -- Accepted in 9th ISCA Speech Synthesis Workshop
null
null
null
cs.CL
http://creativecommons.org/licenses/by/4.0/
Text-to-Speech synthesis in Indian languages has a seen lot of progress over the decade partly due to the annual Blizzard challenges. These systems assume the text to be written in Devanagari or Dravidian scripts which are nearly phonemic orthography scripts. However, the most common form of computer interaction among Indians is ASCII written transliterated text. Such text is generally noisy with many variations in spelling for the same word. In this paper we evaluate three approaches to synthesize speech from such noisy ASCII text: a naive Uni-Grapheme approach, a Multi-Grapheme approach, and a supervised Grapheme-to-Phoneme (G2P) approach. These methods first convert the ASCII text to a phonetic script, and then learn a Deep Neural Network to synthesize speech from that. We train and test our models on Blizzard Challenge datasets that were transliterated to ASCII using crowdsourcing. Our experiments on Hindi, Tamil and Telugu demonstrate that our models generate speech of competetive quality from ASCII text compared to the speech synthesized from the native scripts. All the accompanying transliterated datasets are released for public access.
[ { "version": "v1", "created": "Thu, 18 Aug 2016 18:58:39 GMT" } ]
2016-08-19T00:00:00
[ [ "Ronanki", "Srikanth", "" ], [ "Reddy", "Siva", "" ], [ "Bollepalli", "Bajibabu", "" ], [ "King", "Simon", "" ] ]
TITLE: DNN-based Speech Synthesis for Indian Languages from ASCII text ABSTRACT: Text-to-Speech synthesis in Indian languages has a seen lot of progress over the decade partly due to the annual Blizzard challenges. These systems assume the text to be written in Devanagari or Dravidian scripts which are nearly phonemic orthography scripts. However, the most common form of computer interaction among Indians is ASCII written transliterated text. Such text is generally noisy with many variations in spelling for the same word. In this paper we evaluate three approaches to synthesize speech from such noisy ASCII text: a naive Uni-Grapheme approach, a Multi-Grapheme approach, and a supervised Grapheme-to-Phoneme (G2P) approach. These methods first convert the ASCII text to a phonetic script, and then learn a Deep Neural Network to synthesize speech from that. We train and test our models on Blizzard Challenge datasets that were transliterated to ASCII using crowdsourcing. Our experiments on Hindi, Tamil and Telugu demonstrate that our models generate speech of competetive quality from ASCII text compared to the speech synthesized from the native scripts. All the accompanying transliterated datasets are released for public access.
no_new_dataset
0.942823
1608.05380
Amira Ghenai Amira Ghenai
Amira Ghenai, Moustafa M.Ghanem
Exploring Trust-Aware Neighbourhood in Trust-based Recommendation
null
null
null
null
cs.IR cs.SI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Traditional Recommender Systems (RS) do not consider any personal user information beyond rating history. Such information, on the other hand, is widely available on social networking sites (Facebook, Twitter). As a result, social networks have recently been used in recommendation systems. In this paper, we propose an efficient method for incorporating social signals into the recommendation process by building a trust network which supplements the users' rating profiles. We first show the effect of different cold-start users types on the Collaborative Filtering (CF) technique in several real-world datasets. Later, we propose a "Trust-Aware Neighbourhood" algorithm which addresses a performance issue of the former by limiting the trusted neighbourhood. We show the doubling of the rating coverage compared to the traditional CF technique, and a significant improvement in the accuracy for some datasets. Focusing specifically on cold-start users, we propose a "Hybrid Trust-Aware Neighbourhood" algorithm which expands the neighbourhood by considering both trust and rating history of the users. We show a near complete coverage with a rich trust network dataset-- Flixster. We conclude by discussing the potential implementation of this algorithm in a budget-constrained cloud environment.
[ { "version": "v1", "created": "Thu, 18 Aug 2016 19:21:08 GMT" } ]
2016-08-19T00:00:00
[ [ "Ghenai", "Amira", "" ], [ "Ghanem", "Moustafa M.", "" ] ]
TITLE: Exploring Trust-Aware Neighbourhood in Trust-based Recommendation ABSTRACT: Traditional Recommender Systems (RS) do not consider any personal user information beyond rating history. Such information, on the other hand, is widely available on social networking sites (Facebook, Twitter). As a result, social networks have recently been used in recommendation systems. In this paper, we propose an efficient method for incorporating social signals into the recommendation process by building a trust network which supplements the users' rating profiles. We first show the effect of different cold-start users types on the Collaborative Filtering (CF) technique in several real-world datasets. Later, we propose a "Trust-Aware Neighbourhood" algorithm which addresses a performance issue of the former by limiting the trusted neighbourhood. We show the doubling of the rating coverage compared to the traditional CF technique, and a significant improvement in the accuracy for some datasets. Focusing specifically on cold-start users, we propose a "Hybrid Trust-Aware Neighbourhood" algorithm which expands the neighbourhood by considering both trust and rating history of the users. We show a near complete coverage with a rich trust network dataset-- Flixster. We conclude by discussing the potential implementation of this algorithm in a budget-constrained cloud environment.
no_new_dataset
0.947284
1412.0477
Luca Del Pero
Luca Del Pero and Susanna Ricco and Rahul Sukthankar and Vittorio Ferrari
Recovering Spatiotemporal Correspondence between Deformable Objects by Exploiting Consistent Foreground Motion in Video
9 pages, 14 figures. This article is obsolete. Its contents are now covered in arXiv:1511.09319, where we discuss a comprehensive system for behavior discovery and spatial alignment of articulated object classes from unstructured video (available at https://arxiv.org/abs/1511.09319)
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Given unstructured videos of deformable objects, we automatically recover spatiotemporal correspondences to map one object to another (such as animals in the wild). While traditional methods based on appearance fail in such challenging conditions, we exploit consistency in object motion between instances. Our approach discovers pairs of short video intervals where the object moves in a consistent manner and uses these candidates as seeds for spatial alignment. We model the spatial correspondence between the point trajectories on the object in one interval to those in the other using a time-varying Thin Plate Spline deformation model. On a large dataset of tiger and horse videos, our method automatically aligns thousands of pairs of frames to a high accuracy, and outperforms the popular SIFT Flow algorithm.
[ { "version": "v1", "created": "Mon, 1 Dec 2014 13:47:52 GMT" }, { "version": "v2", "created": "Fri, 24 Apr 2015 22:52:04 GMT" }, { "version": "v3", "created": "Tue, 16 Aug 2016 22:33:33 GMT" } ]
2016-08-18T00:00:00
[ [ "Del Pero", "Luca", "" ], [ "Ricco", "Susanna", "" ], [ "Sukthankar", "Rahul", "" ], [ "Ferrari", "Vittorio", "" ] ]
TITLE: Recovering Spatiotemporal Correspondence between Deformable Objects by Exploiting Consistent Foreground Motion in Video ABSTRACT: Given unstructured videos of deformable objects, we automatically recover spatiotemporal correspondences to map one object to another (such as animals in the wild). While traditional methods based on appearance fail in such challenging conditions, we exploit consistency in object motion between instances. Our approach discovers pairs of short video intervals where the object moves in a consistent manner and uses these candidates as seeds for spatial alignment. We model the spatial correspondence between the point trajectories on the object in one interval to those in the other using a time-varying Thin Plate Spline deformation model. On a large dataset of tiger and horse videos, our method automatically aligns thousands of pairs of frames to a high accuracy, and outperforms the popular SIFT Flow algorithm.
no_new_dataset
0.95594
1509.05371
Felix Trier
Peter Burkert, Felix Trier, Muhammad Zeshan Afzal, Andreas Dengel, Marcus Liwicki
DeXpression: Deep Convolutional Neural Network for Expression Recognition
Under consideration for publication in Pattern Recognition Letters
null
null
null
cs.CV cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a convolutional neural network (CNN) architecture for facial expression recognition. The proposed architecture is independent of any hand-crafted feature extraction and performs better than the earlier proposed convolutional neural network based approaches. We visualize the automatically extracted features which have been learned by the network in order to provide a better understanding. The standard datasets, i.e. Extended Cohn-Kanade (CKP) and MMI Facial Expression Databse are used for the quantitative evaluation. On the CKP set the current state of the art approach, using CNNs, achieves an accuracy of 99.2%. For the MMI dataset, currently the best accuracy for emotion recognition is 93.33%. The proposed architecture achieves 99.6% for CKP and 98.63% for MMI, therefore performing better than the state of the art using CNNs. Automatic facial expression recognition has a broad spectrum of applications such as human-computer interaction and safety systems. This is due to the fact that non-verbal cues are important forms of communication and play a pivotal role in interpersonal communication. The performance of the proposed architecture endorses the efficacy and reliable usage of the proposed work for real world applications.
[ { "version": "v1", "created": "Thu, 17 Sep 2015 18:49:10 GMT" }, { "version": "v2", "created": "Wed, 17 Aug 2016 19:34:55 GMT" } ]
2016-08-18T00:00:00
[ [ "Burkert", "Peter", "" ], [ "Trier", "Felix", "" ], [ "Afzal", "Muhammad Zeshan", "" ], [ "Dengel", "Andreas", "" ], [ "Liwicki", "Marcus", "" ] ]
TITLE: DeXpression: Deep Convolutional Neural Network for Expression Recognition ABSTRACT: We propose a convolutional neural network (CNN) architecture for facial expression recognition. The proposed architecture is independent of any hand-crafted feature extraction and performs better than the earlier proposed convolutional neural network based approaches. We visualize the automatically extracted features which have been learned by the network in order to provide a better understanding. The standard datasets, i.e. Extended Cohn-Kanade (CKP) and MMI Facial Expression Databse are used for the quantitative evaluation. On the CKP set the current state of the art approach, using CNNs, achieves an accuracy of 99.2%. For the MMI dataset, currently the best accuracy for emotion recognition is 93.33%. The proposed architecture achieves 99.6% for CKP and 98.63% for MMI, therefore performing better than the state of the art using CNNs. Automatic facial expression recognition has a broad spectrum of applications such as human-computer interaction and safety systems. This is due to the fact that non-verbal cues are important forms of communication and play a pivotal role in interpersonal communication. The performance of the proposed architecture endorses the efficacy and reliable usage of the proposed work for real world applications.
no_new_dataset
0.946892
1603.06182
Haimin Zhang
Haimin Zhang
Modelling Temporal Information Using Discrete Fourier Transform for Video Classification
to be revised
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recently, video classification attracts intensive research efforts. However, most existing works are based on framelevel visual features, which might fail to model the temporal information, e.g. characteristics accumulated along time. In order to capture video temporal information, we propose to analyse features in frequency domain transformed by discrete Fourier transform (DFT features). Frame-level features are firstly extract by a pre-trained deep convolutional neural network (CNN). Then, time domain features are transformed and interpolated into DFT features. CNN and DFT features are further encoded by using different pooling methods and fused for video classification. In this way, static image features extracted from a pre-trained deep CNN and temporal information represented by DFT features are jointly considered for video classification. We test our method for video emotion classification and action recognition. Experimental results demonstrate that combining DFT features can effectively capture temporal information and therefore improve the performance of both video emotion classification and action recognition. Our approach has achieved a state-of-the-art performance on the largest video emotion dataset (VideoEmotion-8 dataset) and competitive results on UCF-101.
[ { "version": "v1", "created": "Sun, 20 Mar 2016 04:28:21 GMT" }, { "version": "v2", "created": "Tue, 22 Mar 2016 00:42:37 GMT" }, { "version": "v3", "created": "Wed, 20 Jul 2016 07:29:40 GMT" }, { "version": "v4", "created": "Thu, 21 Jul 2016 01:17:17 GMT" }, { "version": "v5", "created": "Wed, 17 Aug 2016 00:48:55 GMT" } ]
2016-08-18T00:00:00
[ [ "Zhang", "Haimin", "" ] ]
TITLE: Modelling Temporal Information Using Discrete Fourier Transform for Video Classification ABSTRACT: Recently, video classification attracts intensive research efforts. However, most existing works are based on framelevel visual features, which might fail to model the temporal information, e.g. characteristics accumulated along time. In order to capture video temporal information, we propose to analyse features in frequency domain transformed by discrete Fourier transform (DFT features). Frame-level features are firstly extract by a pre-trained deep convolutional neural network (CNN). Then, time domain features are transformed and interpolated into DFT features. CNN and DFT features are further encoded by using different pooling methods and fused for video classification. In this way, static image features extracted from a pre-trained deep CNN and temporal information represented by DFT features are jointly considered for video classification. We test our method for video emotion classification and action recognition. Experimental results demonstrate that combining DFT features can effectively capture temporal information and therefore improve the performance of both video emotion classification and action recognition. Our approach has achieved a state-of-the-art performance on the largest video emotion dataset (VideoEmotion-8 dataset) and competitive results on UCF-101.
no_new_dataset
0.946448
1608.04783
Aileme Omogbai Aileme Omogbai
Aileme Omogbai
Application of multiview techniques to NHANES dataset
null
null
null
null
cs.LG stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Disease prediction or classification using health datasets involve using well-known predictors associated with the disease as features for the models. This study considers multiple data components of an individual's health, using the relationship between variables to generate features that may improve the performance of disease classification models. In order to capture information from different aspects of the data, this project uses a multiview learning approach, using Canonical Correlation Analysis (CCA), a technique that finds projections with maximum correlations between two data views. Data categories collected from the NHANES survey (1999-2014) are used as views to learn the multiview representations. The usefulness of the representations is demonstrated by applying them as features in a Diabetes classification task.
[ { "version": "v1", "created": "Tue, 16 Aug 2016 21:20:30 GMT" } ]
2016-08-18T00:00:00
[ [ "Omogbai", "Aileme", "" ] ]
TITLE: Application of multiview techniques to NHANES dataset ABSTRACT: Disease prediction or classification using health datasets involve using well-known predictors associated with the disease as features for the models. This study considers multiple data components of an individual's health, using the relationship between variables to generate features that may improve the performance of disease classification models. In order to capture information from different aspects of the data, this project uses a multiview learning approach, using Canonical Correlation Analysis (CCA), a technique that finds projections with maximum correlations between two data views. Data categories collected from the NHANES survey (1999-2014) are used as views to learn the multiview representations. The usefulness of the representations is demonstrated by applying them as features in a Diabetes classification task.
no_new_dataset
0.94801
1608.04830
Truyen Tran
Kien Do, Truyen Tran, Dinh Phung and Svetha Venkatesh
Outlier Detection on Mixed-Type Data: An Energy-based Approach
null
null
null
null
stat.ML cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Outlier detection amounts to finding data points that differ significantly from the norm. Classic outlier detection methods are largely designed for single data type such as continuous or discrete. However, real world data is increasingly heterogeneous, where a data point can have both discrete and continuous attributes. Handling mixed-type data in a disciplined way remains a great challenge. In this paper, we propose a new unsupervised outlier detection method for mixed-type data based on Mixed-variate Restricted Boltzmann Machine (Mv.RBM). The Mv.RBM is a principled probabilistic method that models data density. We propose to use \emph{free-energy} derived from Mv.RBM as outlier score to detect outliers as those data points lying in low density regions. The method is fast to learn and compute, is scalable to massive datasets. At the same time, the outlier score is identical to data negative log-density up-to an additive constant. We evaluate the proposed method on synthetic and real-world datasets and demonstrate that (a) a proper handling mixed-types is necessary in outlier detection, and (b) free-energy of Mv.RBM is a powerful and efficient outlier scoring method, which is highly competitive against state-of-the-arts.
[ { "version": "v1", "created": "Wed, 17 Aug 2016 01:41:40 GMT" } ]
2016-08-18T00:00:00
[ [ "Do", "Kien", "" ], [ "Tran", "Truyen", "" ], [ "Phung", "Dinh", "" ], [ "Venkatesh", "Svetha", "" ] ]
TITLE: Outlier Detection on Mixed-Type Data: An Energy-based Approach ABSTRACT: Outlier detection amounts to finding data points that differ significantly from the norm. Classic outlier detection methods are largely designed for single data type such as continuous or discrete. However, real world data is increasingly heterogeneous, where a data point can have both discrete and continuous attributes. Handling mixed-type data in a disciplined way remains a great challenge. In this paper, we propose a new unsupervised outlier detection method for mixed-type data based on Mixed-variate Restricted Boltzmann Machine (Mv.RBM). The Mv.RBM is a principled probabilistic method that models data density. We propose to use \emph{free-energy} derived from Mv.RBM as outlier score to detect outliers as those data points lying in low density regions. The method is fast to learn and compute, is scalable to massive datasets. At the same time, the outlier score is identical to data negative log-density up-to an additive constant. We evaluate the proposed method on synthetic and real-world datasets and demonstrate that (a) a proper handling mixed-types is necessary in outlier detection, and (b) free-energy of Mv.RBM is a powerful and efficient outlier scoring method, which is highly competitive against state-of-the-arts.
no_new_dataset
0.948489
1608.04875
Sandipan Sikdar
Sandipan Sikdar, Matteo Marsili, Niloy Ganguly, Animesh Mukherjee
Anomalies in the peer-review system: A case study of the journal of High Energy Physics
25th ACM International Conference on Information and Knowledge Management (CIKM 2016)
null
10.1145/2983323.2983675
null
cs.DL cs.CY
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Peer-review system has long been relied upon for bringing quality research to the notice of the scientific community and also preventing flawed research from entering into the literature. The need for the peer-review system has often been debated as in numerous cases it has failed in its task and in most of these cases editors and the reviewers were thought to be responsible for not being able to correctly judge the quality of the work. This raises a question "Can the peer-review system be improved?" Since editors and reviewers are the most important pillars of a reviewing system, we in this work, attempt to address a related question - given the editing/reviewing history of the editors or re- viewers "can we identify the under-performing ones?", with citations received by the edited/reviewed papers being used as proxy for quantifying performance. We term such review- ers and editors as anomalous and we believe identifying and removing them shall improve the performance of the peer- review system. Using a massive dataset of Journal of High Energy Physics (JHEP) consisting of 29k papers submitted between 1997 and 2015 with 95 editors and 4035 reviewers and their review history, we identify several factors which point to anomalous behavior of referees and editors. In fact the anomalous editors and reviewers account for 26.8% and 14.5% of the total editors and reviewers respectively and for most of these anomalous reviewers the performance degrades alarmingly over time.
[ { "version": "v1", "created": "Wed, 17 Aug 2016 06:48:08 GMT" } ]
2016-08-18T00:00:00
[ [ "Sikdar", "Sandipan", "" ], [ "Marsili", "Matteo", "" ], [ "Ganguly", "Niloy", "" ], [ "Mukherjee", "Animesh", "" ] ]
TITLE: Anomalies in the peer-review system: A case study of the journal of High Energy Physics ABSTRACT: Peer-review system has long been relied upon for bringing quality research to the notice of the scientific community and also preventing flawed research from entering into the literature. The need for the peer-review system has often been debated as in numerous cases it has failed in its task and in most of these cases editors and the reviewers were thought to be responsible for not being able to correctly judge the quality of the work. This raises a question "Can the peer-review system be improved?" Since editors and reviewers are the most important pillars of a reviewing system, we in this work, attempt to address a related question - given the editing/reviewing history of the editors or re- viewers "can we identify the under-performing ones?", with citations received by the edited/reviewed papers being used as proxy for quantifying performance. We term such review- ers and editors as anomalous and we believe identifying and removing them shall improve the performance of the peer- review system. Using a massive dataset of Journal of High Energy Physics (JHEP) consisting of 29k papers submitted between 1997 and 2015 with 95 editors and 4035 reviewers and their review history, we identify several factors which point to anomalous behavior of referees and editors. In fact the anomalous editors and reviewers account for 26.8% and 14.5% of the total editors and reviewers respectively and for most of these anomalous reviewers the performance degrades alarmingly over time.
no_new_dataset
0.916931
1608.04959
Rakshith Shetty
Rakshith Shetty and Jorma Laaksonen
Frame- and Segment-Level Features and Candidate Pool Evaluation for Video Caption Generation
null
null
10.1145/2964284.2984062
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present our submission to the Microsoft Video to Language Challenge of generating short captions describing videos in the challenge dataset. Our model is based on the encoder--decoder pipeline, popular in image and video captioning systems. We propose to utilize two different kinds of video features, one to capture the video content in terms of objects and attributes, and the other to capture the motion and action information. Using these diverse features we train models specializing in two separate input sub-domains. We then train an evaluator model which is used to pick the best caption from the pool of candidates generated by these domain expert models. We argue that this approach is better suited for the current video captioning task, compared to using a single model, due to the diversity in the dataset. Efficacy of our method is proven by the fact that it was rated best in MSR Video to Language Challenge, as per human evaluation. Additionally, we were ranked second in the automatic evaluation metrics based table.
[ { "version": "v1", "created": "Wed, 17 Aug 2016 13:30:06 GMT" } ]
2016-08-18T00:00:00
[ [ "Shetty", "Rakshith", "" ], [ "Laaksonen", "Jorma", "" ] ]
TITLE: Frame- and Segment-Level Features and Candidate Pool Evaluation for Video Caption Generation ABSTRACT: We present our submission to the Microsoft Video to Language Challenge of generating short captions describing videos in the challenge dataset. Our model is based on the encoder--decoder pipeline, popular in image and video captioning systems. We propose to utilize two different kinds of video features, one to capture the video content in terms of objects and attributes, and the other to capture the motion and action information. Using these diverse features we train models specializing in two separate input sub-domains. We then train an evaluator model which is used to pick the best caption from the pool of candidates generated by these domain expert models. We argue that this approach is better suited for the current video captioning task, compared to using a single model, due to the diversity in the dataset. Efficacy of our method is proven by the fact that it was rated best in MSR Video to Language Challenge, as per human evaluation. Additionally, we were ranked second in the automatic evaluation metrics based table.
no_new_dataset
0.950365
1608.05054
Muhammet Bastan
Muhammet Bastan and Hilal Kandemir and Busra Canturk
MT3S: Mobile Turkish Scene Text-to-Speech System for the Visually Impaired
null
null
null
null
cs.MM
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Reading text is one of the essential needs of the visually impaired people. We developed a mobile system that can read Turkish scene and book text, using a fast gradient-based multi-scale text detection algorithm for real-time operation and Tesseract OCR engine for character recognition. We evaluated the OCR accuracy and running time of our system on a new, publicly available mobile Turkish scene text dataset we constructed and also compared with state-of-the-art systems. Our system proved to be much faster, able to run on a mobile device, with OCR accuracy comparable to the state-of-the-art.
[ { "version": "v1", "created": "Wed, 17 Aug 2016 19:24:23 GMT" } ]
2016-08-18T00:00:00
[ [ "Bastan", "Muhammet", "" ], [ "Kandemir", "Hilal", "" ], [ "Canturk", "Busra", "" ] ]
TITLE: MT3S: Mobile Turkish Scene Text-to-Speech System for the Visually Impaired ABSTRACT: Reading text is one of the essential needs of the visually impaired people. We developed a mobile system that can read Turkish scene and book text, using a fast gradient-based multi-scale text detection algorithm for real-time operation and Tesseract OCR engine for character recognition. We evaluated the OCR accuracy and running time of our system on a new, publicly available mobile Turkish scene text dataset we constructed and also compared with state-of-the-art systems. Our system proved to be much faster, able to run on a mobile device, with OCR accuracy comparable to the state-of-the-art.
new_dataset
0.962532
1604.02129
Scott Workman
Scott Workman, Menghua Zhai, Nathan Jacobs
Horizon Lines in the Wild
British Machine Vision Conference (BMVC) 2016
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The horizon line is an important contextual attribute for a wide variety of image understanding tasks. As such, many methods have been proposed to estimate its location from a single image. These methods typically require the image to contain specific cues, such as vanishing points, coplanar circles, and regular textures, thus limiting their real-world applicability. We introduce a large, realistic evaluation dataset, Horizon Lines in the Wild (HLW), containing natural images with labeled horizon lines. Using this dataset, we investigate the application of convolutional neural networks for directly estimating the horizon line, without requiring any explicit geometric constraints or other special cues. An extensive evaluation shows that using our CNNs, either in isolation or in conjunction with a previous geometric approach, we achieve state-of-the-art results on the challenging HLW dataset and two existing benchmark datasets.
[ { "version": "v1", "created": "Thu, 7 Apr 2016 19:38:24 GMT" }, { "version": "v2", "created": "Tue, 16 Aug 2016 18:48:57 GMT" } ]
2016-08-17T00:00:00
[ [ "Workman", "Scott", "" ], [ "Zhai", "Menghua", "" ], [ "Jacobs", "Nathan", "" ] ]
TITLE: Horizon Lines in the Wild ABSTRACT: The horizon line is an important contextual attribute for a wide variety of image understanding tasks. As such, many methods have been proposed to estimate its location from a single image. These methods typically require the image to contain specific cues, such as vanishing points, coplanar circles, and regular textures, thus limiting their real-world applicability. We introduce a large, realistic evaluation dataset, Horizon Lines in the Wild (HLW), containing natural images with labeled horizon lines. Using this dataset, we investigate the application of convolutional neural networks for directly estimating the horizon line, without requiring any explicit geometric constraints or other special cues. An extensive evaluation shows that using our CNNs, either in isolation or in conjunction with a previous geometric approach, we achieve state-of-the-art results on the challenging HLW dataset and two existing benchmark datasets.
new_dataset
0.968261
1606.06204
Richard Barnes
Richard Barnes
Parallel Priority-Flood Depression Filling For Trillion Cell Digital Elevation Models On Desktops Or Clusters
21 pages, 4 tables, 8 figures
Computers and Geosciences, Volume 96, November 2016, pp. 56-68
10.1016/j.cageo.2016.07.001
null
cs.DC cs.DS
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Algorithms for extracting hydrologic features and properties from digital elevation models (DEMs) are challenged by large datasets, which often cannot fit within a computer's RAM. Depression filling is an important preconditioning step to many of these algorithms. Here, I present a new, linearly-scaling algorithm which parallelizes the Priority-Flood depression-filling algorithm by subdividing a DEM into tiles. Using a single-producer, multi-consumer design, the new algorithm works equally well on one core, multiple cores, or multiple machines and can take advantage of large memories or cope with small ones. Unlike previous algorithms, the new algorithm guarantees a fixed number of memory access and communication events per subdivision of the DEM. In comparison testing, this results in the new algorithm running generally faster while using fewer resources than previous algorithms. For moderately sized tiles, the algorithm exhibits ~60% strong and weak scaling efficiencies up to 48 cores, and linear time scaling across datasets ranging over three orders of magnitude. The largest dataset on which I run the algorithm has 2 trillion (2*10^12) cells. With 48 cores, processing required 4.8 hours wall-time (9.3 compute-days). This test is three orders of magnitude larger than any previously performed in the literature. Complete, well-commented source code and correctness tests are available for download from a repository.
[ { "version": "v1", "created": "Mon, 20 Jun 2016 16:52:12 GMT" }, { "version": "v2", "created": "Mon, 15 Aug 2016 22:35:43 GMT" } ]
2016-08-17T00:00:00
[ [ "Barnes", "Richard", "" ] ]
TITLE: Parallel Priority-Flood Depression Filling For Trillion Cell Digital Elevation Models On Desktops Or Clusters ABSTRACT: Algorithms for extracting hydrologic features and properties from digital elevation models (DEMs) are challenged by large datasets, which often cannot fit within a computer's RAM. Depression filling is an important preconditioning step to many of these algorithms. Here, I present a new, linearly-scaling algorithm which parallelizes the Priority-Flood depression-filling algorithm by subdividing a DEM into tiles. Using a single-producer, multi-consumer design, the new algorithm works equally well on one core, multiple cores, or multiple machines and can take advantage of large memories or cope with small ones. Unlike previous algorithms, the new algorithm guarantees a fixed number of memory access and communication events per subdivision of the DEM. In comparison testing, this results in the new algorithm running generally faster while using fewer resources than previous algorithms. For moderately sized tiles, the algorithm exhibits ~60% strong and weak scaling efficiencies up to 48 cores, and linear time scaling across datasets ranging over three orders of magnitude. The largest dataset on which I run the algorithm has 2 trillion (2*10^12) cells. With 48 cores, processing required 4.8 hours wall-time (9.3 compute-days). This test is three orders of magnitude larger than any previously performed in the literature. Complete, well-commented source code and correctness tests are available for download from a repository.
no_new_dataset
0.950686
1608.00075
Renbo Zhao
Renbo Zhao, Vincent Y. F. Tan, Huan Xu
Online Nonnegative Matrix Factorization with General Divergences
null
null
null
null
stat.ML cs.IT cs.NA math.IT math.OC
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We develop a unified and systematic framework for performing online nonnegative matrix factorization under a wide variety of important divergences. The online nature of our algorithm makes it particularly amenable to large-scale data. We prove that the sequence of learned dictionaries converges almost surely to the set of critical points of the expected loss function. We do so by leveraging the theory of stochastic approximations and projected dynamical systems. This result substantially generalizes the previous results obtained only for the squared-$\ell_2$ loss. Moreover, the novel techniques involved in our analysis open new avenues for analyzing similar matrix factorization problems. The computational efficiency and the quality of the learned dictionary of our algorithm are verified empirically on both synthetic and real datasets. In particular, on the tasks of topic learning, shadow removal and image denoising, our algorithm achieves superior trade-offs between the quality of learned dictionary and running time over the batch and other online NMF algorithms.
[ { "version": "v1", "created": "Sat, 30 Jul 2016 06:07:38 GMT" }, { "version": "v2", "created": "Tue, 2 Aug 2016 02:36:50 GMT" } ]
2016-08-17T00:00:00
[ [ "Zhao", "Renbo", "" ], [ "Tan", "Vincent Y. F.", "" ], [ "Xu", "Huan", "" ] ]
TITLE: Online Nonnegative Matrix Factorization with General Divergences ABSTRACT: We develop a unified and systematic framework for performing online nonnegative matrix factorization under a wide variety of important divergences. The online nature of our algorithm makes it particularly amenable to large-scale data. We prove that the sequence of learned dictionaries converges almost surely to the set of critical points of the expected loss function. We do so by leveraging the theory of stochastic approximations and projected dynamical systems. This result substantially generalizes the previous results obtained only for the squared-$\ell_2$ loss. Moreover, the novel techniques involved in our analysis open new avenues for analyzing similar matrix factorization problems. The computational efficiency and the quality of the learned dictionary of our algorithm are verified empirically on both synthetic and real datasets. In particular, on the tasks of topic learning, shadow removal and image denoising, our algorithm achieves superior trade-offs between the quality of learned dictionary and running time over the batch and other online NMF algorithms.
no_new_dataset
0.943504
1608.03793
Rajiv Shah
Rajiv Shah and Rob Romijnders
Applying Deep Learning to Basketball Trajectories
KDD 2016, Large Scale Sports Analytic Workshop
null
null
null
cs.NE cs.CV cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
One of the emerging trends for sports analytics is the growing use of player and ball tracking data. A parallel development is deep learning predictive approaches that use vast quantities of data with less reliance on feature engineering. This paper applies recurrent neural networks in the form of sequence modeling to predict whether a three-point shot is successful. The models are capable of learning the trajectory of a basketball without any knowledge of physics. For comparison, a baseline static machine learning model with a full set of features, such as angle and velocity, in addition to the positional data is also tested. Using a dataset of over 20,000 three pointers from NBA SportVu data, the models based simply on sequential positional data outperform a static feature rich machine learning model in predicting whether a three-point shot is successful. This suggests deep learning models may offer an improvement to traditional feature based machine learning methods for tracking data.
[ { "version": "v1", "created": "Fri, 12 Aug 2016 13:50:24 GMT" }, { "version": "v2", "created": "Tue, 16 Aug 2016 18:36:44 GMT" } ]
2016-08-17T00:00:00
[ [ "Shah", "Rajiv", "" ], [ "Romijnders", "Rob", "" ] ]
TITLE: Applying Deep Learning to Basketball Trajectories ABSTRACT: One of the emerging trends for sports analytics is the growing use of player and ball tracking data. A parallel development is deep learning predictive approaches that use vast quantities of data with less reliance on feature engineering. This paper applies recurrent neural networks in the form of sequence modeling to predict whether a three-point shot is successful. The models are capable of learning the trajectory of a basketball without any knowledge of physics. For comparison, a baseline static machine learning model with a full set of features, such as angle and velocity, in addition to the positional data is also tested. Using a dataset of over 20,000 three pointers from NBA SportVu data, the models based simply on sequential positional data outperform a static feature rich machine learning model in predicting whether a three-point shot is successful. This suggests deep learning models may offer an improvement to traditional feature based machine learning methods for tracking data.
no_new_dataset
0.943504
1608.04245
Mike Gartrell
Mike Gartrell, Ulrich Paquet, Noam Koenigstein
The Bayesian Low-Rank Determinantal Point Process Mixture Model
9 pages, 6 figures. This article draws heavily from arXiv:1602.05436
null
null
null
stat.ML cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Determinantal point processes (DPPs) are an elegant model for encoding probabilities over subsets, such as shopping baskets, of a ground set, such as an item catalog. They are useful for a number of machine learning tasks, including product recommendation. DPPs are parametrized by a positive semi-definite kernel matrix. Recent work has shown that using a low-rank factorization of this kernel provides remarkable scalability improvements that open the door to training on large-scale datasets and computing online recommendations, both of which are infeasible with standard DPP models that use a full-rank kernel. In this paper we present a low-rank DPP mixture model that allows us to represent the latent structure present in observed subsets as a mixture of a number of component low-rank DPPs, where each component DPP is responsible for representing a portion of the observed data. The mixture model allows us to effectively address the capacity constraints of the low-rank DPP model. We present an efficient and scalable Markov Chain Monte Carlo (MCMC) learning algorithm for our model that uses Gibbs sampling and stochastic gradient Hamiltonian Monte Carlo (SGHMC). Using an evaluation on several real-world product recommendation datasets, we show that our low-rank DPP mixture model provides substantially better predictive performance than is possible with a single low-rank or full-rank DPP, and significantly better performance than several other competing recommendation methods in many cases.
[ { "version": "v1", "created": "Mon, 15 Aug 2016 11:42:51 GMT" }, { "version": "v2", "created": "Tue, 16 Aug 2016 10:41:32 GMT" } ]
2016-08-17T00:00:00
[ [ "Gartrell", "Mike", "" ], [ "Paquet", "Ulrich", "" ], [ "Koenigstein", "Noam", "" ] ]
TITLE: The Bayesian Low-Rank Determinantal Point Process Mixture Model ABSTRACT: Determinantal point processes (DPPs) are an elegant model for encoding probabilities over subsets, such as shopping baskets, of a ground set, such as an item catalog. They are useful for a number of machine learning tasks, including product recommendation. DPPs are parametrized by a positive semi-definite kernel matrix. Recent work has shown that using a low-rank factorization of this kernel provides remarkable scalability improvements that open the door to training on large-scale datasets and computing online recommendations, both of which are infeasible with standard DPP models that use a full-rank kernel. In this paper we present a low-rank DPP mixture model that allows us to represent the latent structure present in observed subsets as a mixture of a number of component low-rank DPPs, where each component DPP is responsible for representing a portion of the observed data. The mixture model allows us to effectively address the capacity constraints of the low-rank DPP model. We present an efficient and scalable Markov Chain Monte Carlo (MCMC) learning algorithm for our model that uses Gibbs sampling and stochastic gradient Hamiltonian Monte Carlo (SGHMC). Using an evaluation on several real-world product recommendation datasets, we show that our low-rank DPP mixture model provides substantially better predictive performance than is possible with a single low-rank or full-rank DPP, and significantly better performance than several other competing recommendation methods in many cases.
no_new_dataset
0.950134
1608.04314
Miaojing Shi
Miaojing Shi and Vittorio Ferrari
Weakly Supervised Object Localization Using Size Estimates
ECCV 2016 camera-ready
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a technique for weakly supervised object localization (WSOL), building on the observation that WSOL algorithms usually work better on images with bigger objects. Instead of training the object detector on the entire training set at the same time, we propose a curriculum learning strategy to feed training images into the WSOL learning loop in an order from images containing bigger objects down to smaller ones. To automatically determine the order, we train a regressor to estimate the size of the object given the whole image as input. Furthermore, we use these size estimates to further improve the re-localization step of WSOL by assigning weights to object proposals according to how close their size matches the estimated object size. We demonstrate the effectiveness of using size order and size weighting on the challenging PASCAL VOC 2007 dataset, where we achieve a significant improvement over existing state-of-the-art WSOL techniques.
[ { "version": "v1", "created": "Mon, 15 Aug 2016 16:07:24 GMT" }, { "version": "v2", "created": "Tue, 16 Aug 2016 11:31:41 GMT" } ]
2016-08-17T00:00:00
[ [ "Shi", "Miaojing", "" ], [ "Ferrari", "Vittorio", "" ] ]
TITLE: Weakly Supervised Object Localization Using Size Estimates ABSTRACT: We present a technique for weakly supervised object localization (WSOL), building on the observation that WSOL algorithms usually work better on images with bigger objects. Instead of training the object detector on the entire training set at the same time, we propose a curriculum learning strategy to feed training images into the WSOL learning loop in an order from images containing bigger objects down to smaller ones. To automatically determine the order, we train a regressor to estimate the size of the object given the whole image as input. Furthermore, we use these size estimates to further improve the re-localization step of WSOL by assigning weights to object proposals according to how close their size matches the estimated object size. We demonstrate the effectiveness of using size order and size weighting on the challenging PASCAL VOC 2007 dataset, where we achieve a significant improvement over existing state-of-the-art WSOL techniques.
no_new_dataset
0.951997
1608.04442
Mayank Kejriwal
Mayank Kejriwal, Daniel P. Miranker
Experience: Type alignment on DBpedia and Freebase
null
null
null
null
cs.DB
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Linked Open Data exhibits growth in both volume and variety of published data. Due to this variety, instances of many different types (e.g. Person) can be found in published datasets. Type alignment is the problem of automatically matching types (in a possibly many-many fashion) between two such datasets. Type alignment is an important preprocessing step in instance matching. Instance matching concerns identifying pairs of instances referring to the same underlying entity. By performing type alignment a priori, only instances conforming to aligned types are processed together, leading to significant savings. This article describes a type alignment experience with two large-scale cross-domain RDF knowledge graphs, DBpedia and Freebase, that contain hundreds, or even thousands, of unique types. Specifically, we present a MapReduce-based type alignment algorithm and show that there are at least three reasonable ways of evaluating type alignment within the larger context of instance matching. We comment on the consistency of those results, and note some general observations for researchers evaluating similar algorithms on cross-domain graphs.
[ { "version": "v1", "created": "Mon, 15 Aug 2016 23:56:08 GMT" } ]
2016-08-17T00:00:00
[ [ "Kejriwal", "Mayank", "" ], [ "Miranker", "Daniel P.", "" ] ]
TITLE: Experience: Type alignment on DBpedia and Freebase ABSTRACT: Linked Open Data exhibits growth in both volume and variety of published data. Due to this variety, instances of many different types (e.g. Person) can be found in published datasets. Type alignment is the problem of automatically matching types (in a possibly many-many fashion) between two such datasets. Type alignment is an important preprocessing step in instance matching. Instance matching concerns identifying pairs of instances referring to the same underlying entity. By performing type alignment a priori, only instances conforming to aligned types are processed together, leading to significant savings. This article describes a type alignment experience with two large-scale cross-domain RDF knowledge graphs, DBpedia and Freebase, that contain hundreds, or even thousands, of unique types. Specifically, we present a MapReduce-based type alignment algorithm and show that there are at least three reasonable ways of evaluating type alignment within the larger context of instance matching. We comment on the consistency of those results, and note some general observations for researchers evaluating similar algorithms on cross-domain graphs.
no_new_dataset
0.951863
1608.04689
Hongyu Guo
Martin Renqiang Min, Hongyu Guo, Dongjin Song
A Shallow High-Order Parametric Approach to Data Visualization and Compression
null
null
null
null
cs.AI cs.LG stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Explicit high-order feature interactions efficiently capture essential structural knowledge about the data of interest and have been used for constructing generative models. We present a supervised discriminative High-Order Parametric Embedding (HOPE) approach to data visualization and compression. Compared to deep embedding models with complicated deep architectures, HOPE generates more effective high-order feature mapping through an embarrassingly simple shallow model. Furthermore, two approaches to generating a small number of exemplars conveying high-order interactions to represent large-scale data sets are proposed. These exemplars in combination with the feature mapping learned by HOPE effectively capture essential data variations. Moreover, through HOPE, these exemplars are employed to increase the computational efficiency of kNN classification for fast information retrieval by thousands of times. For classification in two-dimensional embedding space on MNIST and USPS datasets, our shallow method HOPE with simple Sigmoid transformations significantly outperforms state-of-the-art supervised deep embedding models based on deep neural networks, and even achieved historically low test error rate of 0.65% in two-dimensional space on MNIST, which demonstrates the representational efficiency and power of supervised shallow models with high-order feature interactions.
[ { "version": "v1", "created": "Tue, 16 Aug 2016 17:54:40 GMT" } ]
2016-08-17T00:00:00
[ [ "Min", "Martin Renqiang", "" ], [ "Guo", "Hongyu", "" ], [ "Song", "Dongjin", "" ] ]
TITLE: A Shallow High-Order Parametric Approach to Data Visualization and Compression ABSTRACT: Explicit high-order feature interactions efficiently capture essential structural knowledge about the data of interest and have been used for constructing generative models. We present a supervised discriminative High-Order Parametric Embedding (HOPE) approach to data visualization and compression. Compared to deep embedding models with complicated deep architectures, HOPE generates more effective high-order feature mapping through an embarrassingly simple shallow model. Furthermore, two approaches to generating a small number of exemplars conveying high-order interactions to represent large-scale data sets are proposed. These exemplars in combination with the feature mapping learned by HOPE effectively capture essential data variations. Moreover, through HOPE, these exemplars are employed to increase the computational efficiency of kNN classification for fast information retrieval by thousands of times. For classification in two-dimensional embedding space on MNIST and USPS datasets, our shallow method HOPE with simple Sigmoid transformations significantly outperforms state-of-the-art supervised deep embedding models based on deep neural networks, and even achieved historically low test error rate of 0.65% in two-dimensional space on MNIST, which demonstrates the representational efficiency and power of supervised shallow models with high-order feature interactions.
no_new_dataset
0.950041
1608.04698
Dan Garant
Dan Garant, David Jensen
Evaluating Causal Models by Comparing Interventional Distributions
null
null
null
null
cs.AI stat.ME
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The predominant method for evaluating the quality of causal models is to measure the graphical accuracy of the learned model structure. We present an alternative method for evaluating causal models that directly measures the accuracy of estimated interventional distributions. We contrast such distributional measures with structural measures, such as structural Hamming distance and structural intervention distance, showing that structural measures often correspond poorly to the accuracy of estimated interventional distributions. We use a number of real and synthetic datasets to illustrate various scenarios in which structural measures provide misleading results with respect to algorithm selection and parameter tuning, and we recommend that distributional measures become the new standard for evaluating causal models.
[ { "version": "v1", "created": "Tue, 16 Aug 2016 18:32:24 GMT" } ]
2016-08-17T00:00:00
[ [ "Garant", "Dan", "" ], [ "Jensen", "David", "" ] ]
TITLE: Evaluating Causal Models by Comparing Interventional Distributions ABSTRACT: The predominant method for evaluating the quality of causal models is to measure the graphical accuracy of the learned model structure. We present an alternative method for evaluating causal models that directly measures the accuracy of estimated interventional distributions. We contrast such distributional measures with structural measures, such as structural Hamming distance and structural intervention distance, showing that structural measures often correspond poorly to the accuracy of estimated interventional distributions. We use a number of real and synthetic datasets to illustrate various scenarios in which structural measures provide misleading results with respect to algorithm selection and parameter tuning, and we recommend that distributional measures become the new standard for evaluating causal models.
no_new_dataset
0.954009
1408.1664
Yetian Chen
Yetian Chen, Jin Tian, Olga Nikolova and Srinivas Aluru
A Parallel Algorithm for Exact Bayesian Structure Discovery in Bayesian Networks
32 pages, 12 figures
null
null
null
cs.AI cs.DC cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Exact Bayesian structure discovery in Bayesian networks requires exponential time and space. Using dynamic programming (DP), the fastest known sequential algorithm computes the exact posterior probabilities of structural features in $O(2(d+1)n2^n)$ time and space, if the number of nodes (variables) in the Bayesian network is $n$ and the in-degree (the number of parents) per node is bounded by a constant $d$. Here we present a parallel algorithm capable of computing the exact posterior probabilities for all $n(n-1)$ edges with optimal parallel space efficiency and nearly optimal parallel time efficiency. That is, if $p=2^k$ processors are used, the run-time reduces to $O(5(d+1)n2^{n-k}+k(n-k)^d)$ and the space usage becomes $O(n2^{n-k})$ per processor. Our algorithm is based the observation that the subproblems in the sequential DP algorithm constitute a $n$-$D$ hypercube. We take a delicate way to coordinate the computation of correlated DP procedures such that large amount of data exchange is suppressed. Further, we develop parallel techniques for two variants of the well-known \emph{zeta transform}, which have applications outside the context of Bayesian networks. We demonstrate the capability of our algorithm on datasets with up to 33 variables and its scalability on up to 2048 processors. We apply our algorithm to a biological data set for discovering the yeast pheromone response pathways.
[ { "version": "v1", "created": "Thu, 7 Aug 2014 17:40:36 GMT" }, { "version": "v2", "created": "Thu, 14 Aug 2014 04:12:09 GMT" }, { "version": "v3", "created": "Sat, 13 Aug 2016 04:25:55 GMT" } ]
2016-08-16T00:00:00
[ [ "Chen", "Yetian", "" ], [ "Tian", "Jin", "" ], [ "Nikolova", "Olga", "" ], [ "Aluru", "Srinivas", "" ] ]
TITLE: A Parallel Algorithm for Exact Bayesian Structure Discovery in Bayesian Networks ABSTRACT: Exact Bayesian structure discovery in Bayesian networks requires exponential time and space. Using dynamic programming (DP), the fastest known sequential algorithm computes the exact posterior probabilities of structural features in $O(2(d+1)n2^n)$ time and space, if the number of nodes (variables) in the Bayesian network is $n$ and the in-degree (the number of parents) per node is bounded by a constant $d$. Here we present a parallel algorithm capable of computing the exact posterior probabilities for all $n(n-1)$ edges with optimal parallel space efficiency and nearly optimal parallel time efficiency. That is, if $p=2^k$ processors are used, the run-time reduces to $O(5(d+1)n2^{n-k}+k(n-k)^d)$ and the space usage becomes $O(n2^{n-k})$ per processor. Our algorithm is based the observation that the subproblems in the sequential DP algorithm constitute a $n$-$D$ hypercube. We take a delicate way to coordinate the computation of correlated DP procedures such that large amount of data exchange is suppressed. Further, we develop parallel techniques for two variants of the well-known \emph{zeta transform}, which have applications outside the context of Bayesian networks. We demonstrate the capability of our algorithm on datasets with up to 33 variables and its scalability on up to 2048 processors. We apply our algorithm to a biological data set for discovering the yeast pheromone response pathways.
no_new_dataset
0.947962
1601.00863
Ming Yan
Zhimin Peng, Tianyu Wu, Yangyang Xu, Ming Yan, Wotao Yin
Coordinate Friendly Structures, Algorithms and Applications
null
Annals of Mathematical Sciences and Applications, 1 (2016), 57-119
10.4310/AMSA.2016.v1.n1.a2
UCLA CAM Report 16-13
math.OC cs.CE cs.DC math.NA stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper focuses on coordinate update methods, which are useful for solving problems involving large or high-dimensional datasets. They decompose a problem into simple subproblems, where each updates one, or a small block of, variables while fixing others. These methods can deal with linear and nonlinear mappings, smooth and nonsmooth functions, as well as convex and nonconvex problems. In addition, they are easy to parallelize. The great performance of coordinate update methods depends on solving simple sub-problems. To derive simple subproblems for several new classes of applications, this paper systematically studies coordinate-friendly operators that perform low-cost coordinate updates. Based on the discovered coordinate friendly operators, as well as operator splitting techniques, we obtain new coordinate update algorithms for a variety of problems in machine learning, image processing, as well as sub-areas of optimization. Several problems are treated with coordinate update for the first time in history. The obtained algorithms are scalable to large instances through parallel and even asynchronous computing. We present numerical examples to illustrate how effective these algorithms are.
[ { "version": "v1", "created": "Tue, 5 Jan 2016 15:33:05 GMT" }, { "version": "v2", "created": "Mon, 7 Mar 2016 23:05:07 GMT" }, { "version": "v3", "created": "Sun, 14 Aug 2016 14:29:53 GMT" } ]
2016-08-16T00:00:00
[ [ "Peng", "Zhimin", "" ], [ "Wu", "Tianyu", "" ], [ "Xu", "Yangyang", "" ], [ "Yan", "Ming", "" ], [ "Yin", "Wotao", "" ] ]
TITLE: Coordinate Friendly Structures, Algorithms and Applications ABSTRACT: This paper focuses on coordinate update methods, which are useful for solving problems involving large or high-dimensional datasets. They decompose a problem into simple subproblems, where each updates one, or a small block of, variables while fixing others. These methods can deal with linear and nonlinear mappings, smooth and nonsmooth functions, as well as convex and nonconvex problems. In addition, they are easy to parallelize. The great performance of coordinate update methods depends on solving simple sub-problems. To derive simple subproblems for several new classes of applications, this paper systematically studies coordinate-friendly operators that perform low-cost coordinate updates. Based on the discovered coordinate friendly operators, as well as operator splitting techniques, we obtain new coordinate update algorithms for a variety of problems in machine learning, image processing, as well as sub-areas of optimization. Several problems are treated with coordinate update for the first time in history. The obtained algorithms are scalable to large instances through parallel and even asynchronous computing. We present numerical examples to illustrate how effective these algorithms are.
no_new_dataset
0.941922
1602.03202
Mohammad Abu Alsheikh
Dusit Niyato, Mohammad Abu Alsheikh, Ping Wang, Dong In Kim, and Zhu Han
Market Model and Optimal Pricing Scheme of Big Data and Internet of Things (IoT)
null
null
10.1109/ICC.2016.7510922
null
cs.GT
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Big data has been emerging as a new approach in utilizing large datasets to optimize complex system operations. Big data is fueled with Internet-of-Things (IoT) services that generate immense sensory data from numerous sensors and devices. While most current research focus of big data is on machine learning and resource management design, the economic modeling and analysis have been largely overlooked. This paper thus investigates the big data market model and optimal pricing scheme. We first study the utility of data from the data science perspective, i.e., using the machine learning methods. We then introduce the market model and develop an optimal pricing scheme afterward. The case study shows clearly the suitability of the proposed data utility functions. The numerical examples demonstrate that big data and IoT service provider can achieve the maximum profit through the proposed market model.
[ { "version": "v1", "created": "Sun, 7 Feb 2016 04:57:17 GMT" } ]
2016-08-16T00:00:00
[ [ "Niyato", "Dusit", "" ], [ "Alsheikh", "Mohammad Abu", "" ], [ "Wang", "Ping", "" ], [ "Kim", "Dong In", "" ], [ "Han", "Zhu", "" ] ]
TITLE: Market Model and Optimal Pricing Scheme of Big Data and Internet of Things (IoT) ABSTRACT: Big data has been emerging as a new approach in utilizing large datasets to optimize complex system operations. Big data is fueled with Internet-of-Things (IoT) services that generate immense sensory data from numerous sensors and devices. While most current research focus of big data is on machine learning and resource management design, the economic modeling and analysis have been largely overlooked. This paper thus investigates the big data market model and optimal pricing scheme. We first study the utility of data from the data science perspective, i.e., using the machine learning methods. We then introduce the market model and develop an optimal pricing scheme afterward. The case study shows clearly the suitability of the proposed data utility functions. The numerical examples demonstrate that big data and IoT service provider can achieve the maximum profit through the proposed market model.
no_new_dataset
0.94801
1602.07031
Mohammad Abu Alsheikh
Mohammad Abu Alsheikh, Dusit Niyato, Shaowei Lin, Hwee-Pink Tan, and Zhu Han
Mobile Big Data Analytics Using Deep Learning and Apache Spark
null
IEEE Network, vol. 30, no. 3, pp. 22-29, June 2016
10.1109/MNET.2016.7474340
null
cs.DC cs.LG cs.NE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The proliferation of mobile devices, such as smartphones and Internet of Things (IoT) gadgets, results in the recent mobile big data (MBD) era. Collecting MBD is unprofitable unless suitable analytics and learning methods are utilized for extracting meaningful information and hidden patterns from data. This article presents an overview and brief tutorial of deep learning in MBD analytics and discusses a scalable learning framework over Apache Spark. Specifically, a distributed deep learning is executed as an iterative MapReduce computing on many Spark workers. Each Spark worker learns a partial deep model on a partition of the overall MBD, and a master deep model is then built by averaging the parameters of all partial models. This Spark-based framework speeds up the learning of deep models consisting of many hidden layers and millions of parameters. We use a context-aware activity recognition application with a real-world dataset containing millions of samples to validate our framework and assess its speedup effectiveness.
[ { "version": "v1", "created": "Tue, 23 Feb 2016 04:32:02 GMT" } ]
2016-08-16T00:00:00
[ [ "Alsheikh", "Mohammad Abu", "" ], [ "Niyato", "Dusit", "" ], [ "Lin", "Shaowei", "" ], [ "Tan", "Hwee-Pink", "" ], [ "Han", "Zhu", "" ] ]
TITLE: Mobile Big Data Analytics Using Deep Learning and Apache Spark ABSTRACT: The proliferation of mobile devices, such as smartphones and Internet of Things (IoT) gadgets, results in the recent mobile big data (MBD) era. Collecting MBD is unprofitable unless suitable analytics and learning methods are utilized for extracting meaningful information and hidden patterns from data. This article presents an overview and brief tutorial of deep learning in MBD analytics and discusses a scalable learning framework over Apache Spark. Specifically, a distributed deep learning is executed as an iterative MapReduce computing on many Spark workers. Each Spark worker learns a partial deep model on a partition of the overall MBD, and a master deep model is then built by averaging the parameters of all partial models. This Spark-based framework speeds up the learning of deep models consisting of many hidden layers and millions of parameters. We use a context-aware activity recognition application with a real-world dataset containing millions of samples to validate our framework and assess its speedup effectiveness.
no_new_dataset
0.944125
1604.00736
Mohammad Abu Alsheikh
Mohammad Abu Alsheikh, Shaowei Lin, Dusit Niyato, Hwee-Pink Tan
Rate-distortion Balanced Data Compression for Wireless Sensor Networks
arXiv admin note: text overlap with arXiv:1408.2948
IEEE Sensors Journal, vol. 16, no. 12, pp. 5072-5083, June15, 2016
10.1109/JSEN.2016.2550599
null
cs.NI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper presents a data compression algorithm with error bound guarantee for wireless sensor networks (WSNs) using compressing neural networks. The proposed algorithm minimizes data congestion and reduces energy consumption by exploring spatio-temporal correlations among data samples. The adaptive rate-distortion feature balances the compressed data size (data rate) with the required error bound guarantee (distortion level). This compression relieves the strain on energy and bandwidth resources while collecting WSN data within tolerable error margins, thereby increasing the scale of WSNs. The algorithm is evaluated using real-world datasets and compared with conventional methods for temporal and spatial data compression. The experimental validation reveals that the proposed algorithm outperforms several existing WSN data compression methods in terms of compression efficiency and signal reconstruction. Moreover, an energy analysis shows that compressing the data can reduce the energy expenditure, and hence expand the service lifespan by several folds.
[ { "version": "v1", "created": "Mon, 4 Apr 2016 04:14:21 GMT" } ]
2016-08-16T00:00:00
[ [ "Alsheikh", "Mohammad Abu", "" ], [ "Lin", "Shaowei", "" ], [ "Niyato", "Dusit", "" ], [ "Tan", "Hwee-Pink", "" ] ]
TITLE: Rate-distortion Balanced Data Compression for Wireless Sensor Networks ABSTRACT: This paper presents a data compression algorithm with error bound guarantee for wireless sensor networks (WSNs) using compressing neural networks. The proposed algorithm minimizes data congestion and reduces energy consumption by exploring spatio-temporal correlations among data samples. The adaptive rate-distortion feature balances the compressed data size (data rate) with the required error bound guarantee (distortion level). This compression relieves the strain on energy and bandwidth resources while collecting WSN data within tolerable error margins, thereby increasing the scale of WSNs. The algorithm is evaluated using real-world datasets and compared with conventional methods for temporal and spatial data compression. The experimental validation reveals that the proposed algorithm outperforms several existing WSN data compression methods in terms of compression efficiency and signal reconstruction. Moreover, an energy analysis shows that compressing the data can reduce the energy expenditure, and hence expand the service lifespan by several folds.
no_new_dataset
0.950273
1607.06986
Shervin Ardeshir
Shervin Ardeshir, Ali Borji
Ego2Top: Matching Viewers in Egocentric and Top-view Videos
European Conference on Computer Vision (ECCV) 2016. Amsterdam, the Netherlands
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Egocentric cameras are becoming increasingly popular and provide us with large amounts of videos, captured from the first person perspective. At the same time, surveillance cameras and drones offer an abundance of visual information, often captured from top-view. Although these two sources of information have been separately studied in the past, they have not been collectively studied and related. Having a set of egocentric cameras and a top-view camera capturing the same area, we propose a framework to identify the egocentric viewers in the top-view video. We utilize two types of features for our assignment procedure. Unary features encode what a viewer (seen from top-view or recording an egocentric video) visually experiences over time. Pairwise features encode the relationship between the visual content of a pair of viewers. Modeling each view (egocentric or top) by a graph, the assignment process is formulated as spectral graph matching. Evaluating our method over a dataset of 50 top-view and 188 egocentric videos taken in different scenarios demonstrates the efficiency of the proposed approach in assigning egocentric viewers to identities present in top-view camera. We also study the effect of different parameters such as the number of egocentric viewers and visual features.
[ { "version": "v1", "created": "Sun, 24 Jul 2016 00:28:01 GMT" }, { "version": "v2", "created": "Sat, 13 Aug 2016 21:49:56 GMT" } ]
2016-08-16T00:00:00
[ [ "Ardeshir", "Shervin", "" ], [ "Borji", "Ali", "" ] ]
TITLE: Ego2Top: Matching Viewers in Egocentric and Top-view Videos ABSTRACT: Egocentric cameras are becoming increasingly popular and provide us with large amounts of videos, captured from the first person perspective. At the same time, surveillance cameras and drones offer an abundance of visual information, often captured from top-view. Although these two sources of information have been separately studied in the past, they have not been collectively studied and related. Having a set of egocentric cameras and a top-view camera capturing the same area, we propose a framework to identify the egocentric viewers in the top-view video. We utilize two types of features for our assignment procedure. Unary features encode what a viewer (seen from top-view or recording an egocentric video) visually experiences over time. Pairwise features encode the relationship between the visual content of a pair of viewers. Modeling each view (egocentric or top) by a graph, the assignment process is formulated as spectral graph matching. Evaluating our method over a dataset of 50 top-view and 188 egocentric videos taken in different scenarios demonstrates the efficiency of the proposed approach in assigning egocentric viewers to identities present in top-view camera. We also study the effect of different parameters such as the number of egocentric viewers and visual features.
no_new_dataset
0.948537
1608.01745
Alireza Shafaei
Alireza Shafaei and James J. Little and Mark Schmidt
Play and Learn: Using Video Games to Train Computer Vision Models
To appear in the British Machine Vision Conference (BMVC), September 2016. -v2: fixed a typo in the references
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Video games are a compelling source of annotated data as they can readily provide fine-grained groundtruth for diverse tasks. However, it is not clear whether the synthetically generated data has enough resemblance to the real-world images to improve the performance of computer vision models in practice. We present experiments assessing the effectiveness on real-world data of systems trained on synthetic RGB images that are extracted from a video game. We collected over 60000 synthetic samples from a modern video game with similar conditions to the real-world CamVid and Cityscapes datasets. We provide several experiments to demonstrate that the synthetically generated RGB images can be used to improve the performance of deep neural networks on both image segmentation and depth estimation. These results show that a convolutional network trained on synthetic data achieves a similar test error to a network that is trained on real-world data for dense image classification. Furthermore, the synthetically generated RGB images can provide similar or better results compared to the real-world datasets if a simple domain adaptation technique is applied. Our results suggest that collaboration with game developers for an accessible interface to gather data is potentially a fruitful direction for future work in computer vision.
[ { "version": "v1", "created": "Fri, 5 Aug 2016 03:16:07 GMT" }, { "version": "v2", "created": "Mon, 15 Aug 2016 19:41:47 GMT" } ]
2016-08-16T00:00:00
[ [ "Shafaei", "Alireza", "" ], [ "Little", "James J.", "" ], [ "Schmidt", "Mark", "" ] ]
TITLE: Play and Learn: Using Video Games to Train Computer Vision Models ABSTRACT: Video games are a compelling source of annotated data as they can readily provide fine-grained groundtruth for diverse tasks. However, it is not clear whether the synthetically generated data has enough resemblance to the real-world images to improve the performance of computer vision models in practice. We present experiments assessing the effectiveness on real-world data of systems trained on synthetic RGB images that are extracted from a video game. We collected over 60000 synthetic samples from a modern video game with similar conditions to the real-world CamVid and Cityscapes datasets. We provide several experiments to demonstrate that the synthetically generated RGB images can be used to improve the performance of deep neural networks on both image segmentation and depth estimation. These results show that a convolutional network trained on synthetic data achieves a similar test error to a network that is trained on real-world data for dense image classification. Furthermore, the synthetically generated RGB images can provide similar or better results compared to the real-world datasets if a simple domain adaptation technique is applied. Our results suggest that collaboration with game developers for an accessible interface to gather data is potentially a fruitful direction for future work in computer vision.
no_new_dataset
0.947624
1608.03507
Ramin Rahnamoun
Ramin Rahnamoun, Reza Rawassizadeh, Arash Maskooki
Learning Mobile App Usage Routine through Learning Automata
5 pages, 2 figures
null
null
null
cs.AI cs.HC
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Since its conception, smart app market has grown exponentially. Success in the app market depends on many factors among which the quality of the app is a significant contributor, such as energy use. Nevertheless, smartphones, as a subset of mobile computing devices. inherit the limited power resource constraint. Therefore, there is a challenge of maintaining the resource while increasing the target app quality. This paper introduces Learning Automata (LA) as an online learning method to learn and predict the app usage routines of the users. Such prediction can leverage the app cache functionality of the operating system and thus (i) decreases app launch time and (ii) preserve battery. Our algorithm, which is an online learning approach, temporally updates and improves the internal states of itself. In particular, it learns the transition probabilities between app launching. Each App launching instance updates the transition probabilities related to that App, and this will result in improving the prediction. We benefit from a real-world lifelogging dataset and our experimental results show considerable success with respect to the two baseline methods that are used currently for smartphone app prediction approaches.
[ { "version": "v1", "created": "Thu, 11 Aug 2016 15:43:55 GMT" }, { "version": "v2", "created": "Sat, 13 Aug 2016 08:08:35 GMT" } ]
2016-08-16T00:00:00
[ [ "Rahnamoun", "Ramin", "" ], [ "Rawassizadeh", "Reza", "" ], [ "Maskooki", "Arash", "" ] ]
TITLE: Learning Mobile App Usage Routine through Learning Automata ABSTRACT: Since its conception, smart app market has grown exponentially. Success in the app market depends on many factors among which the quality of the app is a significant contributor, such as energy use. Nevertheless, smartphones, as a subset of mobile computing devices. inherit the limited power resource constraint. Therefore, there is a challenge of maintaining the resource while increasing the target app quality. This paper introduces Learning Automata (LA) as an online learning method to learn and predict the app usage routines of the users. Such prediction can leverage the app cache functionality of the operating system and thus (i) decreases app launch time and (ii) preserve battery. Our algorithm, which is an online learning approach, temporally updates and improves the internal states of itself. In particular, it learns the transition probabilities between app launching. Each App launching instance updates the transition probabilities related to that App, and this will result in improving the prediction. We benefit from a real-world lifelogging dataset and our experimental results show considerable success with respect to the two baseline methods that are used currently for smartphone app prediction approaches.
no_new_dataset
0.947721
1608.03914
Sirion Vittayakorn
Sirion Vittayakorn, Alexander C. Berg, Tamara L. Berg
When was that made?
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we explore deep learning methods for estimating when objects were made. Automatic methods for this task could potentially be useful for historians, collectors, or any individual interested in estimating when their artifact was created. Direct applications include large-scale data organization or retrieval. Toward this goal, we utilize features from existing deep networks and also fine-tune new networks for temporal estimation. In addition, we create two new datasets of 67,771 dated clothing items from Flickr and museum collections. Our method outperforms both a color-based baseline and previous state of the art methods for temporal estimation. We also provide several analyses of what our networks have learned, and demonstrate applications to identifying temporal inspiration in fashion collections.
[ { "version": "v1", "created": "Fri, 12 Aug 2016 22:03:38 GMT" } ]
2016-08-16T00:00:00
[ [ "Vittayakorn", "Sirion", "" ], [ "Berg", "Alexander C.", "" ], [ "Berg", "Tamara L.", "" ] ]
TITLE: When was that made? ABSTRACT: In this paper, we explore deep learning methods for estimating when objects were made. Automatic methods for this task could potentially be useful for historians, collectors, or any individual interested in estimating when their artifact was created. Direct applications include large-scale data organization or retrieval. Toward this goal, we utilize features from existing deep networks and also fine-tune new networks for temporal estimation. In addition, we create two new datasets of 67,771 dated clothing items from Flickr and museum collections. Our method outperforms both a color-based baseline and previous state of the art methods for temporal estimation. We also provide several analyses of what our networks have learned, and demonstrate applications to identifying temporal inspiration in fashion collections.
new_dataset
0.953535
1608.03932
Liang Lin
Keze Wang and Shengfu Zhai and Hui Cheng and Xiaodan Liang and Liang Lin
Human Pose Estimation from Depth Images via Inference Embedded Multi-task Learning
To appear in ACM Multimedia 2016, full paper (oral), 10 pages, 11 figures
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Human pose estimation (i.e., locating the body parts / joints of a person) is a fundamental problem in human-computer interaction and multimedia applications. Significant progress has been made based on the development of depth sensors, i.e., accessible human pose prediction from still depth images [32]. However, most of the existing approaches to this problem involve several components/models that are independently designed and optimized, leading to suboptimal performances. In this paper, we propose a novel inference-embedded multi-task learning framework for predicting human pose from still depth images, which is implemented with a deep architecture of neural networks. Specifically, we handle two cascaded tasks: i) generating the heat (confidence) maps of body parts via a fully convolutional network (FCN); ii) seeking the optimal configuration of body parts based on the detected body part proposals via an inference built-in MatchNet [10], which measures the appearance and geometric kinematic compatibility of body parts and embodies the dynamic programming inference as an extra network layer. These two tasks are jointly optimized. Our extensive experiments show that the proposed deep model significantly improves the accuracy of human pose estimation over other several state-of-the-art methods or SDKs. We also release a large-scale dataset for comparison, which includes 100K depth images under challenging scenarios.
[ { "version": "v1", "created": "Sat, 13 Aug 2016 03:16:47 GMT" } ]
2016-08-16T00:00:00
[ [ "Wang", "Keze", "" ], [ "Zhai", "Shengfu", "" ], [ "Cheng", "Hui", "" ], [ "Liang", "Xiaodan", "" ], [ "Lin", "Liang", "" ] ]
TITLE: Human Pose Estimation from Depth Images via Inference Embedded Multi-task Learning ABSTRACT: Human pose estimation (i.e., locating the body parts / joints of a person) is a fundamental problem in human-computer interaction and multimedia applications. Significant progress has been made based on the development of depth sensors, i.e., accessible human pose prediction from still depth images [32]. However, most of the existing approaches to this problem involve several components/models that are independently designed and optimized, leading to suboptimal performances. In this paper, we propose a novel inference-embedded multi-task learning framework for predicting human pose from still depth images, which is implemented with a deep architecture of neural networks. Specifically, we handle two cascaded tasks: i) generating the heat (confidence) maps of body parts via a fully convolutional network (FCN); ii) seeking the optimal configuration of body parts based on the detected body part proposals via an inference built-in MatchNet [10], which measures the appearance and geometric kinematic compatibility of body parts and embodies the dynamic programming inference as an extra network layer. These two tasks are jointly optimized. Our extensive experiments show that the proposed deep model significantly improves the accuracy of human pose estimation over other several state-of-the-art methods or SDKs. We also release a large-scale dataset for comparison, which includes 100K depth images under challenging scenarios.
new_dataset
0.960435
1608.03938
Christopher Thompson
Christopher Thompson, Josh Introne, and Clint Young
Determining Health Utilities through Data Mining of Social Media
8 pages, 2 figures, 3 tables
null
null
null
cs.CL cs.AI cs.CY cs.SI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
'Health utilities' measure patient preferences for perfect health compared to specific unhealthy states, such as asthma, a fractured hip, or colon cancer. When integrated over time, these estimations are called quality adjusted life years (QALYs). Until now, characterizing health utilities (HUs) required detailed patient interviews or written surveys. While reliable and specific, this data remained costly due to efforts to locate, enlist and coordinate participants. Thus the scope, context and temporality of diseases examined has remained limited. Now that more than a billion people use social media, we propose a novel strategy: use natural language processing to analyze public online conversations for signals of the severity of medical conditions and correlate these to known HUs using machine learning. In this work, we filter a dataset that originally contained 2 billion tweets for relevant content on 60 diseases. Using this data, our algorithm successfully distinguished mild from severe diseases, which had previously been categorized only by traditional techniques. This represents progress towards two related applications: first, predicting HUs where such information is nonexistent; and second, (where rich HU data already exists) estimating temporal or geographic patterns of disease severity through data mining.
[ { "version": "v1", "created": "Sat, 13 Aug 2016 04:02:38 GMT" } ]
2016-08-16T00:00:00
[ [ "Thompson", "Christopher", "" ], [ "Introne", "Josh", "" ], [ "Young", "Clint", "" ] ]
TITLE: Determining Health Utilities through Data Mining of Social Media ABSTRACT: 'Health utilities' measure patient preferences for perfect health compared to specific unhealthy states, such as asthma, a fractured hip, or colon cancer. When integrated over time, these estimations are called quality adjusted life years (QALYs). Until now, characterizing health utilities (HUs) required detailed patient interviews or written surveys. While reliable and specific, this data remained costly due to efforts to locate, enlist and coordinate participants. Thus the scope, context and temporality of diseases examined has remained limited. Now that more than a billion people use social media, we propose a novel strategy: use natural language processing to analyze public online conversations for signals of the severity of medical conditions and correlate these to known HUs using machine learning. In this work, we filter a dataset that originally contained 2 billion tweets for relevant content on 60 diseases. Using this data, our algorithm successfully distinguished mild from severe diseases, which had previously been categorized only by traditional techniques. This represents progress towards two related applications: first, predicting HUs where such information is nonexistent; and second, (where rich HU data already exists) estimating temporal or geographic patterns of disease severity through data mining.
no_new_dataset
0.943867
1608.03974
Giovanni Montana
Rudra P K Poudel and Pablo Lamata and Giovanni Montana
Recurrent Fully Convolutional Neural Networks for Multi-slice MRI Cardiac Segmentation
MICCAI Workshop RAMBO 2016
null
null
null
stat.ML cs.CV cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In cardiac magnetic resonance imaging, fully-automatic segmentation of the heart enables precise structural and functional measurements to be taken, e.g. from short-axis MR images of the left-ventricle. In this work we propose a recurrent fully-convolutional network (RFCN) that learns image representations from the full stack of 2D slices and has the ability to leverage inter-slice spatial dependences through internal memory units. RFCN combines anatomical detection and segmentation into a single architecture that is trained end-to-end thus significantly reducing computational time, simplifying the segmentation pipeline, and potentially enabling real-time applications. We report on an investigation of RFCN using two datasets, including the publicly available MICCAI 2009 Challenge dataset. Comparisons have been carried out between fully convolutional networks and deep restricted Boltzmann machines, including a recurrent version that leverages inter-slice spatial correlation. Our studies suggest that RFCN produces state-of-the-art results and can substantially improve the delineation of contours near the apex of the heart.
[ { "version": "v1", "created": "Sat, 13 Aug 2016 11:19:22 GMT" } ]
2016-08-16T00:00:00
[ [ "Poudel", "Rudra P K", "" ], [ "Lamata", "Pablo", "" ], [ "Montana", "Giovanni", "" ] ]
TITLE: Recurrent Fully Convolutional Neural Networks for Multi-slice MRI Cardiac Segmentation ABSTRACT: In cardiac magnetic resonance imaging, fully-automatic segmentation of the heart enables precise structural and functional measurements to be taken, e.g. from short-axis MR images of the left-ventricle. In this work we propose a recurrent fully-convolutional network (RFCN) that learns image representations from the full stack of 2D slices and has the ability to leverage inter-slice spatial dependences through internal memory units. RFCN combines anatomical detection and segmentation into a single architecture that is trained end-to-end thus significantly reducing computational time, simplifying the segmentation pipeline, and potentially enabling real-time applications. We report on an investigation of RFCN using two datasets, including the publicly available MICCAI 2009 Challenge dataset. Comparisons have been carried out between fully convolutional networks and deep restricted Boltzmann machines, including a recurrent version that leverages inter-slice spatial correlation. Our studies suggest that RFCN produces state-of-the-art results and can substantially improve the delineation of contours near the apex of the heart.
no_new_dataset
0.949856
1608.04037
Davi Frossard
Davi E. N. Frossard, Igor O. Nunes, Renato A. Krohling
An approach to dealing with missing values in heterogeneous data using k-nearest neighbors
null
null
null
null
cs.LG cs.IR stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Techniques such as clusterization, neural networks and decision making usually rely on algorithms that are not well suited to deal with missing values. However, real world data frequently contains such cases. The simplest solution is to either substitute them by a best guess value or completely disregard the missing values. Unfortunately, both approaches can lead to biased results. In this paper, we propose a technique for dealing with missing values in heterogeneous data using imputation based on the k-nearest neighbors algorithm. It can handle real (which we refer to as crisp henceforward), interval and fuzzy data. The effectiveness of the algorithm is tested on several datasets and the numerical results are promising.
[ { "version": "v1", "created": "Sat, 13 Aug 2016 23:45:21 GMT" } ]
2016-08-16T00:00:00
[ [ "Frossard", "Davi E. N.", "" ], [ "Nunes", "Igor O.", "" ], [ "Krohling", "Renato A.", "" ] ]
TITLE: An approach to dealing with missing values in heterogeneous data using k-nearest neighbors ABSTRACT: Techniques such as clusterization, neural networks and decision making usually rely on algorithms that are not well suited to deal with missing values. However, real world data frequently contains such cases. The simplest solution is to either substitute them by a best guess value or completely disregard the missing values. Unfortunately, both approaches can lead to biased results. In this paper, we propose a technique for dealing with missing values in heterogeneous data using imputation based on the k-nearest neighbors algorithm. It can handle real (which we refer to as crisp henceforward), interval and fuzzy data. The effectiveness of the algorithm is tested on several datasets and the numerical results are promising.
no_new_dataset
0.952442
1608.04045
Kyle Simek
Kyle Simek, Ravishankar Palanivelu, Kobus Barnard
Branching Gaussian Processes with Applications to Spatiotemporal Reconstruction of 3D Trees
ECCV 2016
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a robust method for estimating dynamic 3D curvilinear branching structure from monocular images. While 3D reconstruction from images has been widely studied, estimating thin structure has received less attention. This problem becomes more challenging in the presence of camera error, scene motion, and a constraint that curves are attached in a branching structure. We propose a new general-purpose prior, a branching Gaussian processes (BGP), that models spatial smoothness and temporal dynamics of curves while enforcing attachment between them. We apply this prior to fit 3D trees directly to image data, using an efficient scheme for approximate inference based on expectation propagation. The BGP prior's Gaussian form allows us to approximately marginalize over 3D trees with a given model structure, enabling principled comparison between tree models with varying complexity. We test our approach on a novel multi-view dataset depicting plants with known 3D structures and topologies undergoing small nonrigid motion. Our method outperforms a state-of-the-art 3D reconstruction method designed for non-moving thin structure. We evaluate under several common measures, and we propose a new measure for reconstructions of branching multi-part 3D scenes under motion.
[ { "version": "v1", "created": "Sun, 14 Aug 2016 01:41:07 GMT" } ]
2016-08-16T00:00:00
[ [ "Simek", "Kyle", "" ], [ "Palanivelu", "Ravishankar", "" ], [ "Barnard", "Kobus", "" ] ]
TITLE: Branching Gaussian Processes with Applications to Spatiotemporal Reconstruction of 3D Trees ABSTRACT: We propose a robust method for estimating dynamic 3D curvilinear branching structure from monocular images. While 3D reconstruction from images has been widely studied, estimating thin structure has received less attention. This problem becomes more challenging in the presence of camera error, scene motion, and a constraint that curves are attached in a branching structure. We propose a new general-purpose prior, a branching Gaussian processes (BGP), that models spatial smoothness and temporal dynamics of curves while enforcing attachment between them. We apply this prior to fit 3D trees directly to image data, using an efficient scheme for approximate inference based on expectation propagation. The BGP prior's Gaussian form allows us to approximately marginalize over 3D trees with a given model structure, enabling principled comparison between tree models with varying complexity. We test our approach on a novel multi-view dataset depicting plants with known 3D structures and topologies undergoing small nonrigid motion. Our method outperforms a state-of-the-art 3D reconstruction method designed for non-moving thin structure. We evaluate under several common measures, and we propose a new measure for reconstructions of branching multi-part 3D scenes under motion.
new_dataset
0.96859
1608.04064
Ihsan Ullah
Ihsan Ullah and Alfredo Petrosino
About Pyramid Structure in Convolutional Neural Networks
Published in 2016 International Joint Conference on Neural Networks (IJCNN)
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Deep convolutional neural networks (CNN) brought revolution without any doubt to various challenging tasks, mainly in computer vision. However, their model designing still requires attention to reduce number of learnable parameters, with no meaningful reduction in performance. In this paper we investigate to what extend CNN may take advantage of pyramid structure typical of biological neurons. A generalized statement over convolutional layers from input till fully connected layer is introduced that helps further in understanding and designing a successful deep network. It reduces ambiguity, number of parameters, and their size on disk without degrading overall accuracy. Performance are shown on state-of-the-art models for MNIST, Cifar-10, Cifar-100, and ImageNet-12 datasets. Despite more than 80% reduction in parameters for Caffe_LENET, challenging results are obtained. Further, despite 10-20% reduction in training data along with 10-40% reduction in parameters for AlexNet model and its variations, competitive results are achieved when compared to similar well-engineered deeper architectures.
[ { "version": "v1", "created": "Sun, 14 Aug 2016 06:03:09 GMT" } ]
2016-08-16T00:00:00
[ [ "Ullah", "Ihsan", "" ], [ "Petrosino", "Alfredo", "" ] ]
TITLE: About Pyramid Structure in Convolutional Neural Networks ABSTRACT: Deep convolutional neural networks (CNN) brought revolution without any doubt to various challenging tasks, mainly in computer vision. However, their model designing still requires attention to reduce number of learnable parameters, with no meaningful reduction in performance. In this paper we investigate to what extend CNN may take advantage of pyramid structure typical of biological neurons. A generalized statement over convolutional layers from input till fully connected layer is introduced that helps further in understanding and designing a successful deep network. It reduces ambiguity, number of parameters, and their size on disk without degrading overall accuracy. Performance are shown on state-of-the-art models for MNIST, Cifar-10, Cifar-100, and ImageNet-12 datasets. Despite more than 80% reduction in parameters for Caffe_LENET, challenging results are obtained. Further, despite 10-20% reduction in training data along with 10-40% reduction in parameters for AlexNet model and its variations, competitive results are achieved when compared to similar well-engineered deeper architectures.
no_new_dataset
0.94699
1608.04274
Andrew Calway Dr
Pilailuck Panphattarasap and Andrew Calway
Visual place recognition using landmark distribution descriptors
13 pages
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recent work by Suenderhauf et al. [1] demonstrated improved visual place recognition using proposal regions coupled with features from convolutional neural networks (CNN) to match landmarks between views. In this work we extend the approach by introducing descriptors built from landmark features which also encode the spatial distribution of the landmarks within a view. Matching descriptors then enforces consistency of the relative positions of landmarks between views. This has a significant impact on performance. For example, in experiments on 10 image-pair datasets, each consisting of 200 urban locations with significant differences in viewing positions and conditions, we recorded average precision of around 70% (at 100% recall), compared with 58% obtained using whole image CNN features and 50% for the method in [1].
[ { "version": "v1", "created": "Mon, 15 Aug 2016 14:13:27 GMT" } ]
2016-08-16T00:00:00
[ [ "Panphattarasap", "Pilailuck", "" ], [ "Calway", "Andrew", "" ] ]
TITLE: Visual place recognition using landmark distribution descriptors ABSTRACT: Recent work by Suenderhauf et al. [1] demonstrated improved visual place recognition using proposal regions coupled with features from convolutional neural networks (CNN) to match landmarks between views. In this work we extend the approach by introducing descriptors built from landmark features which also encode the spatial distribution of the landmarks within a view. Matching descriptors then enforces consistency of the relative positions of landmarks between views. This has a significant impact on performance. For example, in experiments on 10 image-pair datasets, each consisting of 200 urban locations with significant differences in viewing positions and conditions, we recorded average precision of around 70% (at 100% recall), compared with 58% obtained using whole image CNN features and 50% for the method in [1].
no_new_dataset
0.95388
1608.04307
Zhangjie Cao
Zhangjie Cao, Mingsheng Long, Qiang Yang
Transitive Hashing Network for Heterogeneous Multimedia Retrieval
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Hashing has been widely applied to large-scale multimedia retrieval due to the storage and retrieval efficiency. Cross-modal hashing enables efficient retrieval from database of one modality in response to a query of another modality. Existing work on cross-modal hashing assumes heterogeneous relationship across modalities for hash function learning. In this paper, we relax the strong assumption by only requiring such heterogeneous relationship in an auxiliary dataset different from the query/database domain. We craft a hybrid deep architecture to simultaneously learn the cross-modal correlation from the auxiliary dataset, and align the dataset distributions between the auxiliary dataset and the query/database domain, which generates transitive hash codes for heterogeneous multimedia retrieval. Extensive experiments exhibit that the proposed approach yields state of the art multimedia retrieval performance on public datasets, i.e. NUS-WIDE, ImageNet-YahooQA.
[ { "version": "v1", "created": "Mon, 15 Aug 2016 15:36:41 GMT" } ]
2016-08-16T00:00:00
[ [ "Cao", "Zhangjie", "" ], [ "Long", "Mingsheng", "" ], [ "Yang", "Qiang", "" ] ]
TITLE: Transitive Hashing Network for Heterogeneous Multimedia Retrieval ABSTRACT: Hashing has been widely applied to large-scale multimedia retrieval due to the storage and retrieval efficiency. Cross-modal hashing enables efficient retrieval from database of one modality in response to a query of another modality. Existing work on cross-modal hashing assumes heterogeneous relationship across modalities for hash function learning. In this paper, we relax the strong assumption by only requiring such heterogeneous relationship in an auxiliary dataset different from the query/database domain. We craft a hybrid deep architecture to simultaneously learn the cross-modal correlation from the auxiliary dataset, and align the dataset distributions between the auxiliary dataset and the query/database domain, which generates transitive hash codes for heterogeneous multimedia retrieval. Extensive experiments exhibit that the proposed approach yields state of the art multimedia retrieval performance on public datasets, i.e. NUS-WIDE, ImageNet-YahooQA.
no_new_dataset
0.945045
1602.08780
Dirk Tasche
Dirk Tasche
Does quantification without adjustments work?
20 pages, 2 figures, major update
null
null
null
stat.ML cs.LG math.ST stat.TH
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Classification is the task of predicting the class labels of objects based on the observation of their features. In contrast, quantification has been defined as the task of determining the prevalences of the different sorts of class labels in a target dataset. The simplest approach to quantification is Classify & Count where a classifier is optimised for classification on a training set and applied to the target dataset for the prediction of class labels. In the case of binary quantification, the number of predicted positive labels is then used as an estimate of the prevalence of the positive class in the target dataset. Since the performance of Classify & Count for quantification is known to be inferior its results typically are subject to adjustments. However, some researchers recently have suggested that Classify & Count might actually work without adjustments if it is based on a classifer that was specifically trained for quantification. We discuss the theoretical foundation for this claim and explore its potential and limitations with a numerical example based on the binormal model with equal variances. In order to identify an optimal quantifier in the binormal setting, we introduce the concept of local Bayes optimality. As a side remark, we present a complete proof of a theorem by Ye et al. (2012).
[ { "version": "v1", "created": "Sun, 28 Feb 2016 22:29:25 GMT" }, { "version": "v2", "created": "Fri, 12 Aug 2016 16:24:05 GMT" } ]
2016-08-15T00:00:00
[ [ "Tasche", "Dirk", "" ] ]
TITLE: Does quantification without adjustments work? ABSTRACT: Classification is the task of predicting the class labels of objects based on the observation of their features. In contrast, quantification has been defined as the task of determining the prevalences of the different sorts of class labels in a target dataset. The simplest approach to quantification is Classify & Count where a classifier is optimised for classification on a training set and applied to the target dataset for the prediction of class labels. In the case of binary quantification, the number of predicted positive labels is then used as an estimate of the prevalence of the positive class in the target dataset. Since the performance of Classify & Count for quantification is known to be inferior its results typically are subject to adjustments. However, some researchers recently have suggested that Classify & Count might actually work without adjustments if it is based on a classifer that was specifically trained for quantification. We discuss the theoretical foundation for this claim and explore its potential and limitations with a numerical example based on the binormal model with equal variances. In order to identify an optimal quantifier in the binormal setting, we introduce the concept of local Bayes optimality. As a side remark, we present a complete proof of a theorem by Ye et al. (2012).
no_new_dataset
0.946745
1603.03235
Amir Soleimani
Amir Soleimani, Kazim Fouladi, Babak N. Araabi
UTSig: A Persian Offline Signature Dataset
15 pages, 6 figures
null
10.1049/iet-bmt.2015.0058
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The pivotal role of datasets in signature verification systems motivates researchers to collect signature samples. Distinct characteristics of Persian signature demands for richer and culture-dependent offline signature datasets. This paper introduces a new and public Persian offline signature dataset, UTSig, that consists of 8280 images from 115 classes. Each class has 27 genuine signatures, 3 opposite-hand signatures, and 42 skilled forgeries made by 6 forgers. Compared with the other public datasets, UTSig has more samples, more classes, and more forgers. We considered various variables including signing period, writing instrument, signature box size, and number of observable samples for forgers in the data collection procedure. By careful examination of main characteristics of offline signature datasets, we observe that Persian signatures have fewer numbers of branch points and end points. We propose and evaluate four different training and test setups for UTSig. Results of our experiments show that training genuine samples along with opposite-hand samples and random forgeries can improve the performance in terms of equal error rate and minimum cost of log likelihood ratio.
[ { "version": "v1", "created": "Thu, 10 Mar 2016 12:23:03 GMT" }, { "version": "v2", "created": "Wed, 6 Apr 2016 12:55:39 GMT" }, { "version": "v3", "created": "Fri, 8 Apr 2016 04:21:25 GMT" }, { "version": "v4", "created": "Fri, 12 Aug 2016 06:58:59 GMT" } ]
2016-08-15T00:00:00
[ [ "Soleimani", "Amir", "" ], [ "Fouladi", "Kazim", "" ], [ "Araabi", "Babak N.", "" ] ]
TITLE: UTSig: A Persian Offline Signature Dataset ABSTRACT: The pivotal role of datasets in signature verification systems motivates researchers to collect signature samples. Distinct characteristics of Persian signature demands for richer and culture-dependent offline signature datasets. This paper introduces a new and public Persian offline signature dataset, UTSig, that consists of 8280 images from 115 classes. Each class has 27 genuine signatures, 3 opposite-hand signatures, and 42 skilled forgeries made by 6 forgers. Compared with the other public datasets, UTSig has more samples, more classes, and more forgers. We considered various variables including signing period, writing instrument, signature box size, and number of observable samples for forgers in the data collection procedure. By careful examination of main characteristics of offline signature datasets, we observe that Persian signatures have fewer numbers of branch points and end points. We propose and evaluate four different training and test setups for UTSig. Results of our experiments show that training genuine samples along with opposite-hand samples and random forgeries can improve the performance in terms of equal error rate and minimum cost of log likelihood ratio.
new_dataset
0.955527
1608.03609
Evan Shelhamer
Evan Shelhamer, Kate Rakelly, Judy Hoffman, Trevor Darrell
Clockwork Convnets for Video Semantic Segmentation
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recent years have seen tremendous progress in still-image segmentation; however the na\"ive application of these state-of-the-art algorithms to every video frame requires considerable computation and ignores the temporal continuity inherent in video. We propose a video recognition framework that relies on two key observations: 1) while pixels may change rapidly from frame to frame, the semantic content of a scene evolves more slowly, and 2) execution can be viewed as an aspect of architecture, yielding purpose-fit computation schedules for networks. We define a novel family of "clockwork" convnets driven by fixed or adaptive clock signals that schedule the processing of different layers at different update rates according to their semantic stability. We design a pipeline schedule to reduce latency for real-time recognition and a fixed-rate schedule to reduce overall computation. Finally, we extend clockwork scheduling to adaptive video processing by incorporating data-driven clocks that can be tuned on unlabeled video. The accuracy and efficiency of clockwork convnets are evaluated on the Youtube-Objects, NYUD, and Cityscapes video datasets.
[ { "version": "v1", "created": "Thu, 11 Aug 2016 20:32:55 GMT" } ]
2016-08-15T00:00:00
[ [ "Shelhamer", "Evan", "" ], [ "Rakelly", "Kate", "" ], [ "Hoffman", "Judy", "" ], [ "Darrell", "Trevor", "" ] ]
TITLE: Clockwork Convnets for Video Semantic Segmentation ABSTRACT: Recent years have seen tremendous progress in still-image segmentation; however the na\"ive application of these state-of-the-art algorithms to every video frame requires considerable computation and ignores the temporal continuity inherent in video. We propose a video recognition framework that relies on two key observations: 1) while pixels may change rapidly from frame to frame, the semantic content of a scene evolves more slowly, and 2) execution can be viewed as an aspect of architecture, yielding purpose-fit computation schedules for networks. We define a novel family of "clockwork" convnets driven by fixed or adaptive clock signals that schedule the processing of different layers at different update rates according to their semantic stability. We design a pipeline schedule to reduce latency for real-time recognition and a fixed-rate schedule to reduce overall computation. Finally, we extend clockwork scheduling to adaptive video processing by incorporating data-driven clocks that can be tuned on unlabeled video. The accuracy and efficiency of clockwork convnets are evaluated on the Youtube-Objects, NYUD, and Cityscapes video datasets.
no_new_dataset
0.945601
1608.03639
Truyen Tran
Trang Pham, Truyen Tran, Dinh Phung, Svetha Venkatesh
Faster Training of Very Deep Networks Via p-Norm Gates
To appear in ICPR'16
null
null
null
stat.ML cs.LG cs.NE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A major contributing factor to the recent advances in deep neural networks is structural units that let sensory information and gradients to propagate easily. Gating is one such structure that acts as a flow control. Gates are employed in many recent state-of-the-art recurrent models such as LSTM and GRU, and feedforward models such as Residual Nets and Highway Networks. This enables learning in very deep networks with hundred layers and helps achieve record-breaking results in vision (e.g., ImageNet with Residual Nets) and NLP (e.g., machine translation with GRU). However, there is limited work in analysing the role of gating in the learning process. In this paper, we propose a flexible $p$-norm gating scheme, which allows user-controllable flow and as a consequence, improve the learning speed. This scheme subsumes other existing gating schemes, including those in GRU, Highway Networks and Residual Nets as special cases. Experiments on large sequence and vector datasets demonstrate that the proposed gating scheme helps improve the learning speed significantly without extra overhead.
[ { "version": "v1", "created": "Thu, 11 Aug 2016 23:48:44 GMT" } ]
2016-08-15T00:00:00
[ [ "Pham", "Trang", "" ], [ "Tran", "Truyen", "" ], [ "Phung", "Dinh", "" ], [ "Venkatesh", "Svetha", "" ] ]
TITLE: Faster Training of Very Deep Networks Via p-Norm Gates ABSTRACT: A major contributing factor to the recent advances in deep neural networks is structural units that let sensory information and gradients to propagate easily. Gating is one such structure that acts as a flow control. Gates are employed in many recent state-of-the-art recurrent models such as LSTM and GRU, and feedforward models such as Residual Nets and Highway Networks. This enables learning in very deep networks with hundred layers and helps achieve record-breaking results in vision (e.g., ImageNet with Residual Nets) and NLP (e.g., machine translation with GRU). However, there is limited work in analysing the role of gating in the learning process. In this paper, we propose a flexible $p$-norm gating scheme, which allows user-controllable flow and as a consequence, improve the learning speed. This scheme subsumes other existing gating schemes, including those in GRU, Highway Networks and Residual Nets as special cases. Experiments on large sequence and vector datasets demonstrate that the proposed gating scheme helps improve the learning speed significantly without extra overhead.
no_new_dataset
0.95253
1608.03658
Yadong Mu
Yadong Mu and Zhu Liu
Deep Hashing: A Joint Approach for Image Signature Learning
10 pages
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Similarity-based image hashing represents crucial technique for visual data storage reduction and expedited image search. Conventional hashing schemes typically feed hand-crafted features into hash functions, which separates the procedures of feature extraction and hash function learning. In this paper, we propose a novel algorithm that concurrently performs feature engineering and non-linear supervised hashing function learning. Our technical contributions in this paper are two-folds: 1) deep network optimization is often achieved by gradient propagation, which critically requires a smooth objective function. The discrete nature of hash codes makes them not amenable for gradient-based optimization. To address this issue, we propose an exponentiated hashing loss function and its bilinear smooth approximation. Effective gradient calculation and propagation are thereby enabled; 2) pre-training is an important trick in supervised deep learning. The impact of pre-training on the hash code quality has never been discussed in current deep hashing literature. We propose a pre-training scheme inspired by recent advance in deep network based image classification, and experimentally demonstrate its effectiveness. Comprehensive quantitative evaluations are conducted on several widely-used image benchmarks. On all benchmarks, our proposed deep hashing algorithm outperforms all state-of-the-art competitors by significant margins. In particular, our algorithm achieves a near-perfect 0.99 in terms of Hamming ranking accuracy with only 12 bits on MNIST, and a new record of 0.74 on the CIFAR10 dataset. In comparison, the best accuracies obtained on CIFAR10 by existing hashing algorithms without or with deep networks are known to be 0.36 and 0.58 respectively.
[ { "version": "v1", "created": "Fri, 12 Aug 2016 02:00:08 GMT" } ]
2016-08-15T00:00:00
[ [ "Mu", "Yadong", "" ], [ "Liu", "Zhu", "" ] ]
TITLE: Deep Hashing: A Joint Approach for Image Signature Learning ABSTRACT: Similarity-based image hashing represents crucial technique for visual data storage reduction and expedited image search. Conventional hashing schemes typically feed hand-crafted features into hash functions, which separates the procedures of feature extraction and hash function learning. In this paper, we propose a novel algorithm that concurrently performs feature engineering and non-linear supervised hashing function learning. Our technical contributions in this paper are two-folds: 1) deep network optimization is often achieved by gradient propagation, which critically requires a smooth objective function. The discrete nature of hash codes makes them not amenable for gradient-based optimization. To address this issue, we propose an exponentiated hashing loss function and its bilinear smooth approximation. Effective gradient calculation and propagation are thereby enabled; 2) pre-training is an important trick in supervised deep learning. The impact of pre-training on the hash code quality has never been discussed in current deep hashing literature. We propose a pre-training scheme inspired by recent advance in deep network based image classification, and experimentally demonstrate its effectiveness. Comprehensive quantitative evaluations are conducted on several widely-used image benchmarks. On all benchmarks, our proposed deep hashing algorithm outperforms all state-of-the-art competitors by significant margins. In particular, our algorithm achieves a near-perfect 0.99 in terms of Hamming ranking accuracy with only 12 bits on MNIST, and a new record of 0.74 on the CIFAR10 dataset. In comparison, the best accuracies obtained on CIFAR10 by existing hashing algorithms without or with deep networks are known to be 0.36 and 0.58 respectively.
no_new_dataset
0.940298
1608.03889
Hao Wu
Hao Wu, Maoyuan Sun, Jilles Vreeken, Nikolaj Tatti, Chris North, Naren Ramakrishnan
Interactive and Iterative Discovery of Entity Network Subgraphs
null
null
null
null
cs.SI cs.DB
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Graph mining to extract interesting components has been studied in various guises, e.g., communities, dense subgraphs, cliques. However, most existing works are based on notions of frequency and connectivity and do not capture subjective interestingness from a user's viewpoint. Furthermore, existing approaches to mine graphs are not interactive and cannot incorporate user feedbacks in any natural manner. In this paper, we address these gaps by proposing a graph maximum entropy model to discover surprising connected subgraph patterns from entity graphs. This model is embedded in an interactive visualization framework to enable human-in-the-loop, model-guided data exploration. Using case studies on real datasets, we demonstrate how interactions between users and the maximum entropy model lead to faster and explainable conclusions.
[ { "version": "v1", "created": "Fri, 12 Aug 2016 19:56:14 GMT" } ]
2016-08-15T00:00:00
[ [ "Wu", "Hao", "" ], [ "Sun", "Maoyuan", "" ], [ "Vreeken", "Jilles", "" ], [ "Tatti", "Nikolaj", "" ], [ "North", "Chris", "" ], [ "Ramakrishnan", "Naren", "" ] ]
TITLE: Interactive and Iterative Discovery of Entity Network Subgraphs ABSTRACT: Graph mining to extract interesting components has been studied in various guises, e.g., communities, dense subgraphs, cliques. However, most existing works are based on notions of frequency and connectivity and do not capture subjective interestingness from a user's viewpoint. Furthermore, existing approaches to mine graphs are not interactive and cannot incorporate user feedbacks in any natural manner. In this paper, we address these gaps by proposing a graph maximum entropy model to discover surprising connected subgraph patterns from entity graphs. This model is embedded in an interactive visualization framework to enable human-in-the-loop, model-guided data exploration. Using case studies on real datasets, we demonstrate how interactions between users and the maximum entropy model lead to faster and explainable conclusions.
no_new_dataset
0.946101
1102.5597
Radim v{R}eh{u}v{r}ek
Radim \v{R}eh{\r{u}}\v{r}ek
Fast and Faster: A Comparison of Two Streamed Matrix Decomposition Algorithms
null
NIPS Workshop on Low-Rank Methods for Large-Scale Machine Learning, 2010
null
null
cs.NA cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
With the explosion of the size of digital dataset, the limiting factor for decomposition algorithms is the \emph{number of passes} over the input, as the input is often stored out-of-core or even off-site. Moreover, we're only interested in algorithms that operate in \emph{constant memory} w.r.t. to the input size, so that arbitrarily large input can be processed. In this paper, we present a practical comparison of two such algorithms: a distributed method that operates in a single pass over the input vs. a streamed two-pass stochastic algorithm. The experiments track the effect of distributed computing, oversampling and memory trade-offs on the accuracy and performance of the two algorithms. To ensure meaningful results, we choose the input to be a real dataset, namely the whole of the English Wikipedia, in the application settings of Latent Semantic Analysis.
[ { "version": "v1", "created": "Mon, 28 Feb 2011 05:26:58 GMT" } ]
2016-08-14T00:00:00
[ [ "Řeh{ů}řek", "Radim", "" ] ]
TITLE: Fast and Faster: A Comparison of Two Streamed Matrix Decomposition Algorithms ABSTRACT: With the explosion of the size of digital dataset, the limiting factor for decomposition algorithms is the \emph{number of passes} over the input, as the input is often stored out-of-core or even off-site. Moreover, we're only interested in algorithms that operate in \emph{constant memory} w.r.t. to the input size, so that arbitrarily large input can be processed. In this paper, we present a practical comparison of two such algorithms: a distributed method that operates in a single pass over the input vs. a streamed two-pass stochastic algorithm. The experiments track the effect of distributed computing, oversampling and memory trade-offs on the accuracy and performance of the two algorithms. To ensure meaningful results, we choose the input to be a real dataset, namely the whole of the English Wikipedia, in the application settings of Latent Semantic Analysis.
no_new_dataset
0.945901
1511.09319
Luca Del Pero
Luca Del Pero, Susanna Ricco, Rahul Sukthankar, Vittorio Ferrari
Behavior Discovery and Alignment of Articulated Object Classes from Unstructured Video
19 pages, 19 figure, 3 tables. arXiv admin note: substantial text overlap with arXiv:1411.7883
International Journal of Computer Vision (IJCV), July 2016
10.1007/S11263-016-0939-9
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose an automatic system for organizing the content of a collection of unstructured videos of an articulated object class (e.g. tiger, horse). By exploiting the recurring motion patterns of the class across videos, our system: 1) identifies its characteristic behaviors; and 2) recovers pixel-to-pixel alignments across different instances. Our system can be useful for organizing video collections for indexing and retrieval. Moreover, it can be a platform for learning the appearance or behaviors of object classes from Internet video. Traditional supervised techniques cannot exploit this wealth of data directly, as they require a large amount of time-consuming manual annotations. The behavior discovery stage generates temporal video intervals, each automatically trimmed to one instance of the discovered behavior, clustered by type. It relies on our novel motion representation for articulated motion based on the displacement of ordered pairs of trajectories (PoTs). The alignment stage aligns hundreds of instances of the class to a great accuracy despite considerable appearance variations (e.g. an adult tiger and a cub). It uses a flexible Thin Plate Spline deformation model that can vary through time. We carefully evaluate each step of our system on a new, fully annotated dataset. On behavior discovery, we outperform the state-of-the-art Improved DTF descriptor. On spatial alignment, we outperform the popular SIFT Flow algorithm.
[ { "version": "v1", "created": "Mon, 30 Nov 2015 14:22:52 GMT" }, { "version": "v2", "created": "Thu, 11 Aug 2016 01:29:20 GMT" } ]
2016-08-12T00:00:00
[ [ "Del Pero", "Luca", "" ], [ "Ricco", "Susanna", "" ], [ "Sukthankar", "Rahul", "" ], [ "Ferrari", "Vittorio", "" ] ]
TITLE: Behavior Discovery and Alignment of Articulated Object Classes from Unstructured Video ABSTRACT: We propose an automatic system for organizing the content of a collection of unstructured videos of an articulated object class (e.g. tiger, horse). By exploiting the recurring motion patterns of the class across videos, our system: 1) identifies its characteristic behaviors; and 2) recovers pixel-to-pixel alignments across different instances. Our system can be useful for organizing video collections for indexing and retrieval. Moreover, it can be a platform for learning the appearance or behaviors of object classes from Internet video. Traditional supervised techniques cannot exploit this wealth of data directly, as they require a large amount of time-consuming manual annotations. The behavior discovery stage generates temporal video intervals, each automatically trimmed to one instance of the discovered behavior, clustered by type. It relies on our novel motion representation for articulated motion based on the displacement of ordered pairs of trajectories (PoTs). The alignment stage aligns hundreds of instances of the class to a great accuracy despite considerable appearance variations (e.g. an adult tiger and a cub). It uses a flexible Thin Plate Spline deformation model that can vary through time. We carefully evaluate each step of our system on a new, fully annotated dataset. On behavior discovery, we outperform the state-of-the-art Improved DTF descriptor. On spatial alignment, we outperform the popular SIFT Flow algorithm.
no_new_dataset
0.948394
1607.02537
Heng Fan
Heng Fan, Xue Mei, Danil Prokhorov and Haibin Ling
Multi-level Contextual RNNs with Attention Model for Scene Labeling
8 pages, 8 figures
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Context in image is crucial for scene labeling while existing methods only exploit local context generated from a small surrounding area of an image patch or a pixel, by contrast long-range and global contextual information is ignored. To handle this issue, we in this work propose a novel approach for scene labeling by exploring multi-level contextual recurrent neural networks (ML-CRNNs). Specifically, we encode three kinds of contextual cues, i.e., local context, global context and image topic context in structural recurrent neural networks (RNNs) to model long-range local and global dependencies in image. In this way, our method is able to `see' the image in terms of both long-range local and holistic views, and make a more reliable inference for image labeling. Besides, we integrate the proposed contextual RNNs into hierarchical convolutional neural networks (CNNs), and exploit dependence relationships in multiple levels to provide rich spatial and semantic information. Moreover, we novelly adopt an attention model to effectively merge multiple levels and show that it outperforms average- or max-pooling fusion strategies. Extensive experiments demonstrate that the proposed approach achieves new state-of-the-art results on the CamVid, SiftFlow and Stanford-background datasets.
[ { "version": "v1", "created": "Fri, 8 Jul 2016 21:51:53 GMT" }, { "version": "v2", "created": "Wed, 10 Aug 2016 21:15:51 GMT" } ]
2016-08-12T00:00:00
[ [ "Fan", "Heng", "" ], [ "Mei", "Xue", "" ], [ "Prokhorov", "Danil", "" ], [ "Ling", "Haibin", "" ] ]
TITLE: Multi-level Contextual RNNs with Attention Model for Scene Labeling ABSTRACT: Context in image is crucial for scene labeling while existing methods only exploit local context generated from a small surrounding area of an image patch or a pixel, by contrast long-range and global contextual information is ignored. To handle this issue, we in this work propose a novel approach for scene labeling by exploring multi-level contextual recurrent neural networks (ML-CRNNs). Specifically, we encode three kinds of contextual cues, i.e., local context, global context and image topic context in structural recurrent neural networks (RNNs) to model long-range local and global dependencies in image. In this way, our method is able to `see' the image in terms of both long-range local and holistic views, and make a more reliable inference for image labeling. Besides, we integrate the proposed contextual RNNs into hierarchical convolutional neural networks (CNNs), and exploit dependence relationships in multiple levels to provide rich spatial and semantic information. Moreover, we novelly adopt an attention model to effectively merge multiple levels and show that it outperforms average- or max-pooling fusion strategies. Extensive experiments demonstrate that the proposed approach achieves new state-of-the-art results on the CamVid, SiftFlow and Stanford-background datasets.
no_new_dataset
0.950227
1608.02341
Nicola Di Mauro
Antonio Vergari and Nicola Di Mauro and Floriana Esposito
Towards Representation Learning with Tractable Probabilistic Models
10 pages, submitted to ECML-PKDD 2016 Doctoral Consortium
null
null
null
cs.LG cs.AI stat.ML
http://creativecommons.org/licenses/by/4.0/
Probabilistic models learned as density estimators can be exploited in representation learning beside being toolboxes used to answer inference queries only. However, how to extract useful representations highly depends on the particular model involved. We argue that tractable inference, i.e. inference that can be computed in polynomial time, can enable general schemes to extract features from black box models. We plan to investigate how Tractable Probabilistic Models (TPMs) can be exploited to generate embeddings by random query evaluations. We devise two experimental designs to assess and compare different TPMs as feature extractors in an unsupervised representation learning framework. We show some experimental results on standard image datasets by applying such a method to Sum-Product Networks and Mixture of Trees as tractable models generating embeddings.
[ { "version": "v1", "created": "Mon, 8 Aug 2016 07:44:24 GMT" } ]
2016-08-12T00:00:00
[ [ "Vergari", "Antonio", "" ], [ "Di Mauro", "Nicola", "" ], [ "Esposito", "Floriana", "" ] ]
TITLE: Towards Representation Learning with Tractable Probabilistic Models ABSTRACT: Probabilistic models learned as density estimators can be exploited in representation learning beside being toolboxes used to answer inference queries only. However, how to extract useful representations highly depends on the particular model involved. We argue that tractable inference, i.e. inference that can be computed in polynomial time, can enable general schemes to extract features from black box models. We plan to investigate how Tractable Probabilistic Models (TPMs) can be exploited to generate embeddings by random query evaluations. We devise two experimental designs to assess and compare different TPMs as feature extractors in an unsupervised representation learning framework. We show some experimental results on standard image datasets by applying such a method to Sum-Product Networks and Mixture of Trees as tractable models generating embeddings.
no_new_dataset
0.944842
1608.03344
Chenwei Zhang
Chenwei Zhang, Sihong Xie, Yaliang Li, Jing Gao, Wei Fan, Philip S. Yu
Multi-source Hierarchical Prediction Consolidation
null
null
null
null
cs.DB cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In big data applications such as healthcare data mining, due to privacy concerns, it is necessary to collect predictions from multiple information sources for the same instance, with raw features being discarded or withheld when aggregating multiple predictions. Besides, crowd-sourced labels need to be aggregated to estimate the ground truth of the data. Because of the imperfect predictive models or human crowdsourcing workers, noisy and conflicting information is ubiquitous and inevitable. Although state-of-the-art aggregation methods have been proposed to handle label spaces with flat structures, as the label space is becoming more and more complicated, aggregation under a label hierarchical structure becomes necessary but has been largely ignored. These label hierarchies can be quite informative as they are usually created by domain experts to make sense of highly complex label correlations for many real-world cases like protein functionality interactions or disease relationships. We propose a novel multi-source hierarchical prediction consolidation method to effectively exploits the complicated hierarchical label structures to resolve the noisy and conflicting information that inherently originates from multiple imperfect sources. We formulate the problem as an optimization problem with a closed-form solution. The proposed method captures the smoothness overall information sources as well as penalizing any consolidation result that violates the constraints derived from the label hierarchy. The hierarchical instance similarity, as well as the consolidation result, are inferred in a totally unsupervised, iterative fashion. Experimental results on both synthetic and real-world datasets show the effectiveness of the proposed method over existing alternatives.
[ { "version": "v1", "created": "Thu, 11 Aug 2016 01:55:04 GMT" } ]
2016-08-12T00:00:00
[ [ "Zhang", "Chenwei", "" ], [ "Xie", "Sihong", "" ], [ "Li", "Yaliang", "" ], [ "Gao", "Jing", "" ], [ "Fan", "Wei", "" ], [ "Yu", "Philip S.", "" ] ]
TITLE: Multi-source Hierarchical Prediction Consolidation ABSTRACT: In big data applications such as healthcare data mining, due to privacy concerns, it is necessary to collect predictions from multiple information sources for the same instance, with raw features being discarded or withheld when aggregating multiple predictions. Besides, crowd-sourced labels need to be aggregated to estimate the ground truth of the data. Because of the imperfect predictive models or human crowdsourcing workers, noisy and conflicting information is ubiquitous and inevitable. Although state-of-the-art aggregation methods have been proposed to handle label spaces with flat structures, as the label space is becoming more and more complicated, aggregation under a label hierarchical structure becomes necessary but has been largely ignored. These label hierarchies can be quite informative as they are usually created by domain experts to make sense of highly complex label correlations for many real-world cases like protein functionality interactions or disease relationships. We propose a novel multi-source hierarchical prediction consolidation method to effectively exploits the complicated hierarchical label structures to resolve the noisy and conflicting information that inherently originates from multiple imperfect sources. We formulate the problem as an optimization problem with a closed-form solution. The proposed method captures the smoothness overall information sources as well as penalizing any consolidation result that violates the constraints derived from the label hierarchy. The hierarchical instance similarity, as well as the consolidation result, are inferred in a totally unsupervised, iterative fashion. Experimental results on both synthetic and real-world datasets show the effectiveness of the proposed method over existing alternatives.
no_new_dataset
0.95253
1608.03410
Tatiana Tommasi
Tatiana Tommasi, Arun Mallya, Bryan Plummer, Svetlana Lazebnik, Alexander C. Berg, Tamara L. Berg
Solving Visual Madlibs with Multiple Cues
accepted at BMVC 2016
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper focuses on answering fill-in-the-blank style multiple choice questions from the Visual Madlibs dataset. Previous approaches to Visual Question Answering (VQA) have mainly used generic image features from networks trained on the ImageNet dataset, despite the wide scope of questions. In contrast, our approach employs features derived from networks trained for specialized tasks of scene classification, person activity prediction, and person and object attribute prediction. We also present a method for selecting sub-regions of an image that are relevant for evaluating the appropriateness of a putative answer. Visual features are computed both from the whole image and from local regions, while sentences are mapped to a common space using a simple normalized canonical correlation analysis (CCA) model. Our results show a significant improvement over the previous state of the art, and indicate that answering different question types benefits from examining a variety of image cues and carefully choosing informative image sub-regions.
[ { "version": "v1", "created": "Thu, 11 Aug 2016 09:51:21 GMT" } ]
2016-08-12T00:00:00
[ [ "Tommasi", "Tatiana", "" ], [ "Mallya", "Arun", "" ], [ "Plummer", "Bryan", "" ], [ "Lazebnik", "Svetlana", "" ], [ "Berg", "Alexander C.", "" ], [ "Berg", "Tamara L.", "" ] ]
TITLE: Solving Visual Madlibs with Multiple Cues ABSTRACT: This paper focuses on answering fill-in-the-blank style multiple choice questions from the Visual Madlibs dataset. Previous approaches to Visual Question Answering (VQA) have mainly used generic image features from networks trained on the ImageNet dataset, despite the wide scope of questions. In contrast, our approach employs features derived from networks trained for specialized tasks of scene classification, person activity prediction, and person and object attribute prediction. We also present a method for selecting sub-regions of an image that are relevant for evaluating the appropriateness of a putative answer. Visual features are computed both from the whole image and from local regions, while sentences are mapped to a common space using a simple normalized canonical correlation analysis (CCA) model. Our results show a significant improvement over the previous state of the art, and indicate that answering different question types benefits from examining a variety of image cues and carefully choosing informative image sub-regions.
no_new_dataset
0.948489
1608.03474
Buyu Liu
Buyu Liu and Xuming He
Learning Dynamic Hierarchical Models for Anytime Scene Labeling
Accepted by ECCV 2016
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
With increasing demand for efficient image and video analysis, test-time cost of scene parsing becomes critical for many large-scale or time-sensitive vision applications. We propose a dynamic hierarchical model for anytime scene labeling that allows us to achieve flexible trade-offs between efficiency and accuracy in pixel-level prediction. In particular, our approach incorporates the cost of feature computation and model inference, and optimizes the model performance for any given test-time budget by learning a sequence of image-adaptive hierarchical models. We formulate this anytime representation learning as a Markov Decision Process with a discrete-continuous state-action space. A high-quality policy of feature and model selection is learned based on an approximate policy iteration method with action proposal mechanism. We demonstrate the advantages of our dynamic non-myopic anytime scene parsing on three semantic segmentation datasets, which achieves $90\%$ of the state-of-the-art performances by using $15\%$ of their overall costs.
[ { "version": "v1", "created": "Thu, 11 Aug 2016 14:19:31 GMT" } ]
2016-08-12T00:00:00
[ [ "Liu", "Buyu", "" ], [ "He", "Xuming", "" ] ]
TITLE: Learning Dynamic Hierarchical Models for Anytime Scene Labeling ABSTRACT: With increasing demand for efficient image and video analysis, test-time cost of scene parsing becomes critical for many large-scale or time-sensitive vision applications. We propose a dynamic hierarchical model for anytime scene labeling that allows us to achieve flexible trade-offs between efficiency and accuracy in pixel-level prediction. In particular, our approach incorporates the cost of feature computation and model inference, and optimizes the model performance for any given test-time budget by learning a sequence of image-adaptive hierarchical models. We formulate this anytime representation learning as a Markov Decision Process with a discrete-continuous state-action space. A high-quality policy of feature and model selection is learned based on an approximate policy iteration method with action proposal mechanism. We demonstrate the advantages of our dynamic non-myopic anytime scene parsing on three semantic segmentation datasets, which achieves $90\%$ of the state-of-the-art performances by using $15\%$ of their overall costs.
no_new_dataset
0.947381
1608.03556
Nikos Bikakis
Nikos Bikakis, Chrisa Tsinaraki, Nektarios Gioldasis, Ioannis Stavrakantonakis, Stavros Christodoulakis
The XML and Semantic Web Worlds: Technologies, Interoperability and Integration. A Survey of the State of the Art
This paper appears in "Semantic Hyper/Multi-media Adaptation: Schemes and Applications", Springer 2013. arXiv admin note: text overlap with arXiv:1311.0536
null
null
null
cs.DB
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the context of the emergent Web of Data, a large number of organizations, institutes and companies (e.g., DBpedia, Geonames, PubMed ACM, IEEE, NASA, BBC) adopt the Linked Data practices and publish their data utilizing Semantic Web (SW) technologies. On the other hand, the dominant standard for information exchange in the Web today is XML. Many international standards (e.g., Dublin Core, MPEG-7, METS, TEI, IEEE LOM) have been expressed in XML Schema resulting to a large number of XML datasets. The SW and XML worlds and their developed infrastructures are based on different data models, semantics and query languages. Thus, it is crucial to provide interoperability and integration mechanisms to bridge the gap between the SW and XML worlds. In this chapter, we give an overview and a comparison of the technologies and the standards adopted by the XML and SW worlds. In addition, we outline the latest efforts from the W3C groups, including the latest working drafts and recommendations (e.g., OWL 2, SPARQL 1.1, XML Schema 1.1). Moreover, we present a survey of the research approaches which aim to provide interoperability and integration between the XML and SW worlds. Finally, we present the SPARQL2XQuery and XS2OWL Frameworks, which bridge the gap and create an interoperable environment between the two worlds. These Frameworks provide mechanisms for: (a) Query translation (SPARQL to XQuery translation); (b) Mapping specification and generation (Ontology to XML Schema mapping); and (c) Schema transformation (XML Schema to OWL transformation).
[ { "version": "v1", "created": "Thu, 11 Aug 2016 18:03:04 GMT" } ]
2016-08-12T00:00:00
[ [ "Bikakis", "Nikos", "" ], [ "Tsinaraki", "Chrisa", "" ], [ "Gioldasis", "Nektarios", "" ], [ "Stavrakantonakis", "Ioannis", "" ], [ "Christodoulakis", "Stavros", "" ] ]
TITLE: The XML and Semantic Web Worlds: Technologies, Interoperability and Integration. A Survey of the State of the Art ABSTRACT: In the context of the emergent Web of Data, a large number of organizations, institutes and companies (e.g., DBpedia, Geonames, PubMed ACM, IEEE, NASA, BBC) adopt the Linked Data practices and publish their data utilizing Semantic Web (SW) technologies. On the other hand, the dominant standard for information exchange in the Web today is XML. Many international standards (e.g., Dublin Core, MPEG-7, METS, TEI, IEEE LOM) have been expressed in XML Schema resulting to a large number of XML datasets. The SW and XML worlds and their developed infrastructures are based on different data models, semantics and query languages. Thus, it is crucial to provide interoperability and integration mechanisms to bridge the gap between the SW and XML worlds. In this chapter, we give an overview and a comparison of the technologies and the standards adopted by the XML and SW worlds. In addition, we outline the latest efforts from the W3C groups, including the latest working drafts and recommendations (e.g., OWL 2, SPARQL 1.1, XML Schema 1.1). Moreover, we present a survey of the research approaches which aim to provide interoperability and integration between the XML and SW worlds. Finally, we present the SPARQL2XQuery and XS2OWL Frameworks, which bridge the gap and create an interoperable environment between the two worlds. These Frameworks provide mechanisms for: (a) Query translation (SPARQL to XQuery translation); (b) Mapping specification and generation (Ontology to XML Schema mapping); and (c) Schema transformation (XML Schema to OWL transformation).
no_new_dataset
0.949576
1303.7474
Matthew Anderson
Matthew Anderson, Geng-Shen Fu, Ronald Phlypo, and T\"ulay Adal{\i}
Independent Vector Analysis: Identification Conditions and Performance Bounds
14 pages, 5 figures, in review for IEEE Trans. on Signal Processing
null
10.1109/TSP.2014.2333554
null
cs.LG cs.IT math.IT stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recently, an extension of independent component analysis (ICA) from one to multiple datasets, termed independent vector analysis (IVA), has been the subject of significant research interest. IVA has also been shown to be a generalization of Hotelling's canonical correlation analysis. In this paper, we provide the identification conditions for a general IVA formulation, which accounts for linear, nonlinear, and sample-to-sample dependencies. The identification conditions are a generalization of previous results for ICA and for IVA when samples are independently and identically distributed. Furthermore, a principal aim of IVA is the identification of dependent sources between datasets. Thus, we provide the additional conditions for when the arbitrary ordering of the sources within each dataset is common. Performance bounds in terms of the Cramer-Rao lower bound are also provided for the demixing matrices and interference to source ratio. The performance of two IVA algorithms are compared to the theoretical bounds.
[ { "version": "v1", "created": "Fri, 29 Mar 2013 19:52:31 GMT" } ]
2016-08-11T00:00:00
[ [ "Anderson", "Matthew", "" ], [ "Fu", "Geng-Shen", "" ], [ "Phlypo", "Ronald", "" ], [ "Adalı", "Tülay", "" ] ]
TITLE: Independent Vector Analysis: Identification Conditions and Performance Bounds ABSTRACT: Recently, an extension of independent component analysis (ICA) from one to multiple datasets, termed independent vector analysis (IVA), has been the subject of significant research interest. IVA has also been shown to be a generalization of Hotelling's canonical correlation analysis. In this paper, we provide the identification conditions for a general IVA formulation, which accounts for linear, nonlinear, and sample-to-sample dependencies. The identification conditions are a generalization of previous results for ICA and for IVA when samples are independently and identically distributed. Furthermore, a principal aim of IVA is the identification of dependent sources between datasets. Thus, we provide the additional conditions for when the arbitrary ordering of the sources within each dataset is common. Performance bounds in terms of the Cramer-Rao lower bound are also provided for the demixing matrices and interference to source ratio. The performance of two IVA algorithms are compared to the theoretical bounds.
no_new_dataset
0.950641
1507.01073
Makoto Yamada
Makoto Yamada, Wenzhao Lian, Amit Goyal, Jianhui Chen, Kishan Wimalawarne, Suleiman A Khan, Samuel Kaski, Hiroshi Mamitsuka, Yi Chang
Convex Factorization Machine for Regression
null
null
null
null
stat.ML cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose the convex factorization machine (CFM), which is a convex variant of the widely used Factorization Machines (FMs). Specifically, we employ a linear+quadratic model and regularize the linear term with the $\ell_2$-regularizer and the quadratic term with the trace norm regularizer. Then, we formulate the CFM optimization as a semidefinite programming problem and propose an efficient optimization procedure with Hazan's algorithm. A key advantage of CFM over existing FMs is that it can find a globally optimal solution, while FMs may get a poor locally optimal solution since the objective function of FMs is non-convex. In addition, the proposed algorithm is simple yet effective and can be implemented easily. Finally, CFM is a general factorization method and can also be used for other factorization problems including including multi-view matrix factorization and tensor completion problems. Through synthetic and movielens datasets, we first show that the proposed CFM achieves results competitive to FMs. Furthermore, in a toxicogenomics prediction task, we show that CFM outperforms a state-of-the-art tensor factorization method.
[ { "version": "v1", "created": "Sat, 4 Jul 2015 05:54:29 GMT" }, { "version": "v2", "created": "Tue, 18 Aug 2015 17:17:17 GMT" }, { "version": "v3", "created": "Wed, 23 Dec 2015 08:52:42 GMT" }, { "version": "v4", "created": "Mon, 8 Aug 2016 14:55:49 GMT" }, { "version": "v5", "created": "Wed, 10 Aug 2016 01:23:56 GMT" } ]
2016-08-11T00:00:00
[ [ "Yamada", "Makoto", "" ], [ "Lian", "Wenzhao", "" ], [ "Goyal", "Amit", "" ], [ "Chen", "Jianhui", "" ], [ "Wimalawarne", "Kishan", "" ], [ "Khan", "Suleiman A", "" ], [ "Kaski", "Samuel", "" ], [ "Mamitsuka", "Hiroshi", "" ], [ "Chang", "Yi", "" ] ]
TITLE: Convex Factorization Machine for Regression ABSTRACT: We propose the convex factorization machine (CFM), which is a convex variant of the widely used Factorization Machines (FMs). Specifically, we employ a linear+quadratic model and regularize the linear term with the $\ell_2$-regularizer and the quadratic term with the trace norm regularizer. Then, we formulate the CFM optimization as a semidefinite programming problem and propose an efficient optimization procedure with Hazan's algorithm. A key advantage of CFM over existing FMs is that it can find a globally optimal solution, while FMs may get a poor locally optimal solution since the objective function of FMs is non-convex. In addition, the proposed algorithm is simple yet effective and can be implemented easily. Finally, CFM is a general factorization method and can also be used for other factorization problems including including multi-view matrix factorization and tensor completion problems. Through synthetic and movielens datasets, we first show that the proposed CFM achieves results competitive to FMs. Furthermore, in a toxicogenomics prediction task, we show that CFM outperforms a state-of-the-art tensor factorization method.
no_new_dataset
0.9434
1608.00272
Licheng Yu
Licheng Yu, Patrick Poirson, Shan Yang, Alexander C. Berg, Tamara L. Berg
Modeling Context in Referring Expressions
19 pages, 6 figures, in ECCV 2016; authors, references and acknowledgement updated
null
null
null
cs.CV cs.CL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Humans refer to objects in their environments all the time, especially in dialogue with other people. We explore generating and comprehending natural language referring expressions for objects in images. In particular, we focus on incorporating better measures of visual context into referring expression models and find that visual comparison to other objects within an image helps improve performance significantly. We also develop methods to tie the language generation process together, so that we generate expressions for all objects of a particular category jointly. Evaluation on three recent datasets - RefCOCO, RefCOCO+, and RefCOCOg, shows the advantages of our methods for both referring expression generation and comprehension.
[ { "version": "v1", "created": "Sun, 31 Jul 2016 22:21:42 GMT" }, { "version": "v2", "created": "Tue, 2 Aug 2016 22:52:17 GMT" }, { "version": "v3", "created": "Wed, 10 Aug 2016 19:01:37 GMT" } ]
2016-08-11T00:00:00
[ [ "Yu", "Licheng", "" ], [ "Poirson", "Patrick", "" ], [ "Yang", "Shan", "" ], [ "Berg", "Alexander C.", "" ], [ "Berg", "Tamara L.", "" ] ]
TITLE: Modeling Context in Referring Expressions ABSTRACT: Humans refer to objects in their environments all the time, especially in dialogue with other people. We explore generating and comprehending natural language referring expressions for objects in images. In particular, we focus on incorporating better measures of visual context into referring expression models and find that visual comparison to other objects within an image helps improve performance significantly. We also develop methods to tie the language generation process together, so that we generate expressions for all objects of a particular category jointly. Evaluation on three recent datasets - RefCOCO, RefCOCO+, and RefCOCOg, shows the advantages of our methods for both referring expression generation and comprehension.
no_new_dataset
0.949995
1608.03049
Ziwei Liu
Ziwei Liu, Sijie Yan, Ping Luo, Xiaogang Wang, Xiaoou Tang
Fashion Landmark Detection in the Wild
To appear in European Conference on Computer Vision (ECCV) 2016
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Visual fashion analysis has attracted many attentions in the recent years. Previous work represented clothing regions by either bounding boxes or human joints. This work presents fashion landmark detection or fashion alignment, which is to predict the positions of functional key points defined on the fashion items, such as the corners of neckline, hemline, and cuff. To encourage future studies, we introduce a fashion landmark dataset with over 120K images, where each image is labeled with eight landmarks. With this dataset, we study fashion alignment by cascading multiple convolutional neural networks in three stages. These stages gradually improve the accuracies of landmark predictions. Extensive experiments demonstrate the effectiveness of the proposed method, as well as its generalization ability to pose estimation. Fashion landmark is also compared to clothing bounding boxes and human joints in two applications, fashion attribute prediction and clothes retrieval, showing that fashion landmark is a more discriminative representation to understand fashion images.
[ { "version": "v1", "created": "Wed, 10 Aug 2016 05:07:10 GMT" } ]
2016-08-11T00:00:00
[ [ "Liu", "Ziwei", "" ], [ "Yan", "Sijie", "" ], [ "Luo", "Ping", "" ], [ "Wang", "Xiaogang", "" ], [ "Tang", "Xiaoou", "" ] ]
TITLE: Fashion Landmark Detection in the Wild ABSTRACT: Visual fashion analysis has attracted many attentions in the recent years. Previous work represented clothing regions by either bounding boxes or human joints. This work presents fashion landmark detection or fashion alignment, which is to predict the positions of functional key points defined on the fashion items, such as the corners of neckline, hemline, and cuff. To encourage future studies, we introduce a fashion landmark dataset with over 120K images, where each image is labeled with eight landmarks. With this dataset, we study fashion alignment by cascading multiple convolutional neural networks in three stages. These stages gradually improve the accuracies of landmark predictions. Extensive experiments demonstrate the effectiveness of the proposed method, as well as its generalization ability to pose estimation. Fashion landmark is also compared to clothing bounding boxes and human joints in two applications, fashion attribute prediction and clothes retrieval, showing that fashion landmark is a more discriminative representation to understand fashion images.
new_dataset
0.963472
1608.03066
Benjamin Drayer
Benjamin Drayer and Thomas Brox
Object Detection, Tracking, and Motion Segmentation for Object-level Video Segmentation
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present an approach for object segmentation in videos that combines frame-level object detection with concepts from object tracking and motion segmentation. The approach extracts temporally consistent object tubes based on an off-the-shelf detector. Besides the class label for each tube, this provides a location prior that is independent of motion. For the final video segmentation, we combine this information with motion cues. The method overcomes the typical problems of weakly supervised/unsupervised video segmentation, such as scenes with no motion, dominant camera motion, and objects that move as a unit. In contrast to most tracking methods, it provides an accurate, temporally consistent segmentation of each object. We report results on four video segmentation datasets: YouTube Objects, SegTrackv2, egoMotion, and FBMS.
[ { "version": "v1", "created": "Wed, 10 Aug 2016 07:46:56 GMT" } ]
2016-08-11T00:00:00
[ [ "Drayer", "Benjamin", "" ], [ "Brox", "Thomas", "" ] ]
TITLE: Object Detection, Tracking, and Motion Segmentation for Object-level Video Segmentation ABSTRACT: We present an approach for object segmentation in videos that combines frame-level object detection with concepts from object tracking and motion segmentation. The approach extracts temporally consistent object tubes based on an off-the-shelf detector. Besides the class label for each tube, this provides a location prior that is independent of motion. For the final video segmentation, we combine this information with motion cues. The method overcomes the typical problems of weakly supervised/unsupervised video segmentation, such as scenes with no motion, dominant camera motion, and objects that move as a unit. In contrast to most tracking methods, it provides an accurate, temporally consistent segmentation of each object. We report results on four video segmentation datasets: YouTube Objects, SegTrackv2, egoMotion, and FBMS.
no_new_dataset
0.956391
1608.03217
Ali Diba
Ali Diba, Ali Mohammad Pazandeh, Hamed Pirsiavash, Luc Van Gool
DeepCAMP: Deep Convolutional Action & Attribute Mid-Level Patterns
in CVPR 2016
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The recognition of human actions and the determination of human attributes are two tasks that call for fine-grained classification. Indeed, often rather small and inconspicuous objects and features have to be detected to tell their classes apart. In order to deal with this challenge, we propose a novel convolutional neural network that mines mid-level image patches that are sufficiently dedicated to resolve the corresponding subtleties. In particular, we train a newly de- signed CNN (DeepPattern) that learns discriminative patch groups. There are two innovative aspects to this. On the one hand we pay attention to contextual information in an origi- nal fashion. On the other hand, we let an iteration of feature learning and patch clustering purify the set of dedicated patches that we use. We validate our method for action clas- sification on two challenging datasets: PASCAL VOC 2012 Action and Stanford 40 Actions, and for attribute recogni- tion we use the Berkeley Attributes of People dataset. Our discriminative mid-level mining CNN obtains state-of-the- art results on these datasets, without a need for annotations about parts and poses.
[ { "version": "v1", "created": "Wed, 10 Aug 2016 15:43:10 GMT" } ]
2016-08-11T00:00:00
[ [ "Diba", "Ali", "" ], [ "Pazandeh", "Ali Mohammad", "" ], [ "Pirsiavash", "Hamed", "" ], [ "Van Gool", "Luc", "" ] ]
TITLE: DeepCAMP: Deep Convolutional Action & Attribute Mid-Level Patterns ABSTRACT: The recognition of human actions and the determination of human attributes are two tasks that call for fine-grained classification. Indeed, often rather small and inconspicuous objects and features have to be detected to tell their classes apart. In order to deal with this challenge, we propose a novel convolutional neural network that mines mid-level image patches that are sufficiently dedicated to resolve the corresponding subtleties. In particular, we train a newly de- signed CNN (DeepPattern) that learns discriminative patch groups. There are two innovative aspects to this. On the one hand we pay attention to contextual information in an origi- nal fashion. On the other hand, we let an iteration of feature learning and patch clustering purify the set of dedicated patches that we use. We validate our method for action clas- sification on two challenging datasets: PASCAL VOC 2012 Action and Stanford 40 Actions, and for attribute recogni- tion we use the Berkeley Attributes of People dataset. Our discriminative mid-level mining CNN obtains state-of-the- art results on these datasets, without a need for annotations about parts and poses.
no_new_dataset
0.947527
1409.2585
Georgios Skoumas
Georgios Skoumas and Klaus Arthur Schmid and Gregor Joss\'e and Andreas Z\"ufle and Mario A. Nascimento and Matthias Renz and Dieter Pfoser
Towards Knowledge-Enriched Path Computation
Accepted as a short paper at ACM SIGSPATIAL GIS 2014
null
10.1145/2666310.2666485
null
cs.DB
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Directions and paths, as commonly provided by navigation systems, are usually derived considering absolute metrics, e.g., finding the shortest path within an underlying road network. With the aid of crowdsourced geospatial data we aim at obtaining paths that do not only minimize distance but also lead through more popular areas using knowledge generated by users. We extract spatial relations such as "nearby" or "next to" from travel blogs, that define closeness between pairs of points of interest (PoIs) and quantify each of these relations using a probabilistic model. Subsequently, we create a relationship graph where each node corresponds to a PoI and each edge describes the spatial connection between the respective PoIs. Using Bayesian inference we obtain a probabilistic measure of spatial closeness according to the crowd. Applying this measure to the corresponding road network, we obtain an altered cost function which does not exclusively rely on distance, and enriches an actual road networks taking crowdsourced spatial relations into account. Finally, we propose two routing algorithms on the enriched road networks. To evaluate our approach, we use Flickr photo data as a ground truth for popularity. Our experimental results -- based on real world datasets -- show that the paths computed w.r.t.\ our alternative cost function yield competitive solutions in terms of path length while also providing more "popular" paths, making routing easier and more informative for the user.
[ { "version": "v1", "created": "Tue, 9 Sep 2014 09:51:01 GMT" } ]
2016-08-10T00:00:00
[ [ "Skoumas", "Georgios", "" ], [ "Schmid", "Klaus Arthur", "" ], [ "Jossé", "Gregor", "" ], [ "Züfle", "Andreas", "" ], [ "Nascimento", "Mario A.", "" ], [ "Renz", "Matthias", "" ], [ "Pfoser", "Dieter", "" ] ]
TITLE: Towards Knowledge-Enriched Path Computation ABSTRACT: Directions and paths, as commonly provided by navigation systems, are usually derived considering absolute metrics, e.g., finding the shortest path within an underlying road network. With the aid of crowdsourced geospatial data we aim at obtaining paths that do not only minimize distance but also lead through more popular areas using knowledge generated by users. We extract spatial relations such as "nearby" or "next to" from travel blogs, that define closeness between pairs of points of interest (PoIs) and quantify each of these relations using a probabilistic model. Subsequently, we create a relationship graph where each node corresponds to a PoI and each edge describes the spatial connection between the respective PoIs. Using Bayesian inference we obtain a probabilistic measure of spatial closeness according to the crowd. Applying this measure to the corresponding road network, we obtain an altered cost function which does not exclusively rely on distance, and enriches an actual road networks taking crowdsourced spatial relations into account. Finally, we propose two routing algorithms on the enriched road networks. To evaluate our approach, we use Flickr photo data as a ground truth for popularity. Our experimental results -- based on real world datasets -- show that the paths computed w.r.t.\ our alternative cost function yield competitive solutions in terms of path length while also providing more "popular" paths, making routing easier and more informative for the user.
no_new_dataset
0.951369
1505.04382
Lei Zhang
Lei Zhang and David Zhang
Robust Visual Knowledge Transfer via EDA
This paper has been accepted for publication in IEEE Transactions on Image Processing
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We address the problem of visual knowledge adaptation by leveraging labeled patterns from source domain and a very limited number of labeled instances in target domain to learn a robust classifier for visual categorization. This paper proposes a new extreme learning machine based cross-domain network learning framework, that is called Extreme Learning Machine (ELM) based Domain Adaptation (EDA). It allows us to learn a category transformation and an ELM classifier with random projection by minimizing the l_(2,1)-norm of the network output weights and the learning error simultaneously. The unlabeled target data, as useful knowledge, is also integrated as a fidelity term to guarantee the stability during cross domain learning. It minimizes the matching error between the learned classifier and a base classifier, such that many existing classifiers can be readily incorporated as base classifiers. The network output weights cannot only be analytically determined, but also transferrable. Additionally, a manifold regularization with Laplacian graph is incorporated, such that it is beneficial to semi-supervised learning. Extensively, we also propose a model of multiple views, referred as MvEDA. Experiments on benchmark visual datasets for video event recognition and object recognition, demonstrate that our EDA methods outperform existing cross-domain learning methods.
[ { "version": "v1", "created": "Sun, 17 May 2015 11:23:12 GMT" }, { "version": "v2", "created": "Tue, 9 Aug 2016 07:22:34 GMT" } ]
2016-08-10T00:00:00
[ [ "Zhang", "Lei", "" ], [ "Zhang", "David", "" ] ]
TITLE: Robust Visual Knowledge Transfer via EDA ABSTRACT: We address the problem of visual knowledge adaptation by leveraging labeled patterns from source domain and a very limited number of labeled instances in target domain to learn a robust classifier for visual categorization. This paper proposes a new extreme learning machine based cross-domain network learning framework, that is called Extreme Learning Machine (ELM) based Domain Adaptation (EDA). It allows us to learn a category transformation and an ELM classifier with random projection by minimizing the l_(2,1)-norm of the network output weights and the learning error simultaneously. The unlabeled target data, as useful knowledge, is also integrated as a fidelity term to guarantee the stability during cross domain learning. It minimizes the matching error between the learned classifier and a base classifier, such that many existing classifiers can be readily incorporated as base classifiers. The network output weights cannot only be analytically determined, but also transferrable. Additionally, a manifold regularization with Laplacian graph is incorporated, such that it is beneficial to semi-supervised learning. Extensively, we also propose a model of multiple views, referred as MvEDA. Experiments on benchmark visual datasets for video event recognition and object recognition, demonstrate that our EDA methods outperform existing cross-domain learning methods.
no_new_dataset
0.946941
1512.02413
Julian Yarkony
Shaofei Wang, Steffen Wolf, Charless Fowlkes, Julian Yarkony
Tracking Objects with Higher Order Interactions using Delayed Column Generation
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the problem of multi-target tracking and data association in video. We formulate this in terms of selecting a subset of high-quality tracks subject to the constraint that no pair of selected tracks is associated with a common detection (of an object). This objective is equivalent to the classic NP-hard problem of finding a maximum-weight set packing (MWSP) where tracks correspond to sets and is made further difficult since the number of candidate tracks grows exponentially in the number of detections. We present a relaxation of this combinatorial problem that uses a column generation formulation where the pricing problem is solved via dynamic programming to efficiently explore the space of tracks. We employ row generation to tighten the bound in such a way as to preserve efficient inference in the pricing problem. We show the practical utility of this algorithm for tracking problems in natural and biological video datasets.
[ { "version": "v1", "created": "Tue, 8 Dec 2015 11:41:30 GMT" }, { "version": "v2", "created": "Thu, 14 Jan 2016 04:10:10 GMT" }, { "version": "v3", "created": "Tue, 9 Aug 2016 05:44:51 GMT" } ]
2016-08-10T00:00:00
[ [ "Wang", "Shaofei", "" ], [ "Wolf", "Steffen", "" ], [ "Fowlkes", "Charless", "" ], [ "Yarkony", "Julian", "" ] ]
TITLE: Tracking Objects with Higher Order Interactions using Delayed Column Generation ABSTRACT: We study the problem of multi-target tracking and data association in video. We formulate this in terms of selecting a subset of high-quality tracks subject to the constraint that no pair of selected tracks is associated with a common detection (of an object). This objective is equivalent to the classic NP-hard problem of finding a maximum-weight set packing (MWSP) where tracks correspond to sets and is made further difficult since the number of candidate tracks grows exponentially in the number of detections. We present a relaxation of this combinatorial problem that uses a column generation formulation where the pricing problem is solved via dynamic programming to efficiently explore the space of tracks. We employ row generation to tighten the bound in such a way as to preserve efficient inference in the pricing problem. We show the practical utility of this algorithm for tracking problems in natural and biological video datasets.
no_new_dataset
0.946547
1606.02858
Danqi Chen
Danqi Chen, Jason Bolton, Christopher D. Manning
A Thorough Examination of the CNN/Daily Mail Reading Comprehension Task
ACL 2016, updated results
null
null
null
cs.CL cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Enabling a computer to understand a document so that it can answer comprehension questions is a central, yet unsolved goal of NLP. A key factor impeding its solution by machine learned systems is the limited availability of human-annotated data. Hermann et al. (2015) seek to solve this problem by creating over a million training examples by pairing CNN and Daily Mail news articles with their summarized bullet points, and show that a neural network can then be trained to give good performance on this task. In this paper, we conduct a thorough examination of this new reading comprehension task. Our primary aim is to understand what depth of language understanding is required to do well on this task. We approach this from one side by doing a careful hand-analysis of a small subset of the problems and from the other by showing that simple, carefully designed systems can obtain accuracies of 73.6% and 76.6% on these two datasets, exceeding current state-of-the-art results by 7-10% and approaching what we believe is the ceiling for performance on this task.
[ { "version": "v1", "created": "Thu, 9 Jun 2016 08:19:16 GMT" }, { "version": "v2", "created": "Mon, 8 Aug 2016 21:21:19 GMT" } ]
2016-08-10T00:00:00
[ [ "Chen", "Danqi", "" ], [ "Bolton", "Jason", "" ], [ "Manning", "Christopher D.", "" ] ]
TITLE: A Thorough Examination of the CNN/Daily Mail Reading Comprehension Task ABSTRACT: Enabling a computer to understand a document so that it can answer comprehension questions is a central, yet unsolved goal of NLP. A key factor impeding its solution by machine learned systems is the limited availability of human-annotated data. Hermann et al. (2015) seek to solve this problem by creating over a million training examples by pairing CNN and Daily Mail news articles with their summarized bullet points, and show that a neural network can then be trained to give good performance on this task. In this paper, we conduct a thorough examination of this new reading comprehension task. Our primary aim is to understand what depth of language understanding is required to do well on this task. We approach this from one side by doing a careful hand-analysis of a small subset of the problems and from the other by showing that simple, carefully designed systems can obtain accuracies of 73.6% and 76.6% on these two datasets, exceeding current state-of-the-art results by 7-10% and approaching what we believe is the ceiling for performance on this task.
no_new_dataset
0.940898
1606.03676
Benoit Sagot
Beno\^it Sagot (ALPAGE)
External Lexical Information for Multilingual Part-of-Speech Tagging
null
null
null
null
cs.CL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Morphosyntactic lexicons and word vector representations have both proven useful for improving the accuracy of statistical part-of-speech taggers. Here we compare the performances of four systems on datasets covering 16 languages, two of these systems being feature-based (MEMMs and CRFs) and two of them being neural-based (bi-LSTMs). We show that, on average, all four approaches perform similarly and reach state-of-the-art results. Yet better performances are obtained with our feature-based models on lexically richer datasets (e.g. for morphologically rich languages), whereas neural-based results are higher on datasets with less lexical variability (e.g. for English). These conclusions hold in particular for the MEMM models relying on our system MElt, which benefited from newly designed features. This shows that, under certain conditions, feature-based approaches enriched with morphosyntactic lexicons are competitive with respect to neural methods.
[ { "version": "v1", "created": "Sun, 12 Jun 2016 08:06:55 GMT" }, { "version": "v2", "created": "Tue, 9 Aug 2016 08:41:46 GMT" } ]
2016-08-10T00:00:00
[ [ "Sagot", "Benoît", "", "ALPAGE" ] ]
TITLE: External Lexical Information for Multilingual Part-of-Speech Tagging ABSTRACT: Morphosyntactic lexicons and word vector representations have both proven useful for improving the accuracy of statistical part-of-speech taggers. Here we compare the performances of four systems on datasets covering 16 languages, two of these systems being feature-based (MEMMs and CRFs) and two of them being neural-based (bi-LSTMs). We show that, on average, all four approaches perform similarly and reach state-of-the-art results. Yet better performances are obtained with our feature-based models on lexically richer datasets (e.g. for morphologically rich languages), whereas neural-based results are higher on datasets with less lexical variability (e.g. for English). These conclusions hold in particular for the MEMM models relying on our system MElt, which benefited from newly designed features. This shows that, under certain conditions, feature-based approaches enriched with morphosyntactic lexicons are competitive with respect to neural methods.
no_new_dataset
0.948822
1608.01198
Dong Huang
Dong Huang, Chang-Dong Wang, Jian-Huang Lai, Yun Liang, Shan Bian, Yu Chen
Ensemble-driven support vector clustering: From ensemble learning to automatic parameter estimation
To appear in ICPR 2016
null
null
null
cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Support vector clustering (SVC) is a versatile clustering technique that is able to identify clusters of arbitrary shapes by exploiting the kernel trick. However, one hurdle that restricts the application of SVC lies in its sensitivity to the kernel parameter and the trade-off parameter. Although many extensions of SVC have been developed, to the best of our knowledge, there is still no algorithm that is able to effectively estimate the two crucial parameters in SVC without supervision. In this paper, we propose a novel support vector clustering approach termed ensemble-driven support vector clustering (EDSVC), which for the first time tackles the automatic parameter estimation problem for SVC based on ensemble learning, and is capable of producing robust clustering results in a purely unsupervised manner. Experimental results on multiple real-world datasets demonstrate the effectiveness of our approach.
[ { "version": "v1", "created": "Wed, 3 Aug 2016 14:19:00 GMT" }, { "version": "v2", "created": "Tue, 9 Aug 2016 15:28:15 GMT" } ]
2016-08-10T00:00:00
[ [ "Huang", "Dong", "" ], [ "Wang", "Chang-Dong", "" ], [ "Lai", "Jian-Huang", "" ], [ "Liang", "Yun", "" ], [ "Bian", "Shan", "" ], [ "Chen", "Yu", "" ] ]
TITLE: Ensemble-driven support vector clustering: From ensemble learning to automatic parameter estimation ABSTRACT: Support vector clustering (SVC) is a versatile clustering technique that is able to identify clusters of arbitrary shapes by exploiting the kernel trick. However, one hurdle that restricts the application of SVC lies in its sensitivity to the kernel parameter and the trade-off parameter. Although many extensions of SVC have been developed, to the best of our knowledge, there is still no algorithm that is able to effectively estimate the two crucial parameters in SVC without supervision. In this paper, we propose a novel support vector clustering approach termed ensemble-driven support vector clustering (EDSVC), which for the first time tackles the automatic parameter estimation problem for SVC based on ensemble learning, and is capable of producing robust clustering results in a purely unsupervised manner. Experimental results on multiple real-world datasets demonstrate the effectiveness of our approach.
no_new_dataset
0.948728
1608.02639
Boxiang Dong
Boxiang Dong, Zhengzhang Chen, Hui Wang, Lu-An Tang, Kai Zhang, Ying Lin, Haifeng Chen, Guofei Jiang
GID: Graph-based Intrusion Detection on Massive Process Traces for Enterprise Security Systems
null
null
null
null
cs.CR
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Intrusion detection system (IDS) is an important part of enterprise security system architecture. In particular, anomaly-based IDS has been widely applied to detect abnormal process behaviors that deviate from the majority. However, such abnormal behavior usually consists of a series of low-level heterogeneous events. The gap between the low-level events and the high-level abnormal behaviors makes it hard to infer which single events are related to the real abnormal activities, especially considering that there are massive "noisy" low-level events happening in between. Hence, the existing work that focus on detecting single entities/events can hardly achieve high detection accuracy. Different from previous work, we design and implement GID, an efficient graph-based intrusion detection technique that can identify abnormal event sequences from a massive heterogeneous process traces with high accuracy. GID first builds a compact graph structure to capture the interactions between different system entities. The suspiciousness or anomaly score of process paths is then measured by leveraging random walk technique to the constructed acyclic directed graph. To eliminate the score bias from the path length, the Box-Cox power transformation based approach is introduced to normalize the anomaly scores so that the scores of paths of different lengths have the same distribution. The efficiency of suspicious path discovery is further improved by the proposed optimization scheme. We fully implement our GID algorithm and deploy it into a real enterprise security system, and it greatly helps detect the advanced threats, and optimize the incident response. Executing GID on system monitoring datasets showing that GID is efficient (about 2 million records per minute) and accurate (higher than 80% in terms of detection rate).
[ { "version": "v1", "created": "Mon, 8 Aug 2016 22:09:26 GMT" } ]
2016-08-10T00:00:00
[ [ "Dong", "Boxiang", "" ], [ "Chen", "Zhengzhang", "" ], [ "Wang", "Hui", "" ], [ "Tang", "Lu-An", "" ], [ "Zhang", "Kai", "" ], [ "Lin", "Ying", "" ], [ "Chen", "Haifeng", "" ], [ "Jiang", "Guofei", "" ] ]
TITLE: GID: Graph-based Intrusion Detection on Massive Process Traces for Enterprise Security Systems ABSTRACT: Intrusion detection system (IDS) is an important part of enterprise security system architecture. In particular, anomaly-based IDS has been widely applied to detect abnormal process behaviors that deviate from the majority. However, such abnormal behavior usually consists of a series of low-level heterogeneous events. The gap between the low-level events and the high-level abnormal behaviors makes it hard to infer which single events are related to the real abnormal activities, especially considering that there are massive "noisy" low-level events happening in between. Hence, the existing work that focus on detecting single entities/events can hardly achieve high detection accuracy. Different from previous work, we design and implement GID, an efficient graph-based intrusion detection technique that can identify abnormal event sequences from a massive heterogeneous process traces with high accuracy. GID first builds a compact graph structure to capture the interactions between different system entities. The suspiciousness or anomaly score of process paths is then measured by leveraging random walk technique to the constructed acyclic directed graph. To eliminate the score bias from the path length, the Box-Cox power transformation based approach is introduced to normalize the anomaly scores so that the scores of paths of different lengths have the same distribution. The efficiency of suspicious path discovery is further improved by the proposed optimization scheme. We fully implement our GID algorithm and deploy it into a real enterprise security system, and it greatly helps detect the advanced threats, and optimize the incident response. Executing GID on system monitoring datasets showing that GID is efficient (about 2 million records per minute) and accurate (higher than 80% in terms of detection rate).
no_new_dataset
0.948585
1608.02657
Bin Guo
Yan Liu, Bin Guo, Yang Wang, Wenle Wu, Zhiwen Yu, Daqing Zhang
TaskMe: Multi-Task Allocation in Mobile Crowd Sensing
null
null
null
null
cs.HC
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Task allocation or participant selection is a key issue in Mobile Crowd Sensing (MCS). While previous participant selection approaches mainly focus on selecting a proper subset of users for a single MCS task, multi-task-oriented participant selection is essential and useful for the efficiency of large-scale MCS platforms. This paper proposes TaskMe, a participant selection framework for multi-task MCS environments. In particular, two typical multi-task allocation situations with bi-objective optimization goals are studied: (1) For FPMT (few participants, more tasks), each participant is required to complete multiple tasks and the optimization goal is to maximize the total number of accomplished tasks while minimizing the total movement distance. (2) For MPFT (more participants, few tasks), each participant is selected to perform one task based on pre-registered working areas in view of privacy, and the optimization objective is to minimize total incentive payments while minimizing the total traveling distance. Two optimal algorithms based on the Minimum Cost Maximum Flow theory are proposed for FPMT, and two algorithms based on the multi-objective optimization theory are proposed for MPFT. Experiments verify that the proposed algorithms outperform baselines based on a large-scale real-word dataset under different experiment settings (the number of tasks, various task distributions, etc.).
[ { "version": "v1", "created": "Mon, 8 Aug 2016 23:43:15 GMT" } ]
2016-08-10T00:00:00
[ [ "Liu", "Yan", "" ], [ "Guo", "Bin", "" ], [ "Wang", "Yang", "" ], [ "Wu", "Wenle", "" ], [ "Yu", "Zhiwen", "" ], [ "Zhang", "Daqing", "" ] ]
TITLE: TaskMe: Multi-Task Allocation in Mobile Crowd Sensing ABSTRACT: Task allocation or participant selection is a key issue in Mobile Crowd Sensing (MCS). While previous participant selection approaches mainly focus on selecting a proper subset of users for a single MCS task, multi-task-oriented participant selection is essential and useful for the efficiency of large-scale MCS platforms. This paper proposes TaskMe, a participant selection framework for multi-task MCS environments. In particular, two typical multi-task allocation situations with bi-objective optimization goals are studied: (1) For FPMT (few participants, more tasks), each participant is required to complete multiple tasks and the optimization goal is to maximize the total number of accomplished tasks while minimizing the total movement distance. (2) For MPFT (more participants, few tasks), each participant is selected to perform one task based on pre-registered working areas in view of privacy, and the optimization objective is to minimize total incentive payments while minimizing the total traveling distance. Two optimal algorithms based on the Minimum Cost Maximum Flow theory are proposed for FPMT, and two algorithms based on the multi-objective optimization theory are proposed for MPFT. Experiments verify that the proposed algorithms outperform baselines based on a large-scale real-word dataset under different experiment settings (the number of tasks, various task distributions, etc.).
no_new_dataset
0.949482
1608.02659
Mohamed Ali Mahjoub
Anis Elbahi, Mohamed Nazih Omri, Mohamed Ali Mahjoub, Kamel Garrouch
Mouse Movement and Probabilistic Graphical Models Based E-Learning Activity Recognition Improvement Possibilistic Model
in AJSE 2016
null
null
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Automatically recognizing the e-learning activities is an important task for improving the online learning process. Probabilistic graphical models such as hidden Markov models and conditional random fields have been successfully used in order to identify a Web users activity. For such models, the sequences of observation are crucial for training and inference processes. Despite the efficiency of these probabilistic graphical models in segmenting and labeling stochastic sequences, their performance is adversely affected by the imperfect quality of data used for the construction of sequences of observation. In this paper, a formalism of the possibilistic theory will be used in order to propose a new approach for observation sequences preparation. The eminent contribution of our approach is to evaluate the effect of possibilistic reasoning during the generation of observation sequences on the effectiveness of hidden Markov models and conditional random fields models. Using a dataset containing 51 real manipulations related to three types of learners tasks, the preliminary experiments demonstrate that the sequences of observation obtained based on possibilistic reasoning significantly improve the performance of hidden Marvov models and conditional random fields models in the automatic recognition of the e-learning activities.
[ { "version": "v1", "created": "Mon, 8 Aug 2016 23:48:19 GMT" } ]
2016-08-10T00:00:00
[ [ "Elbahi", "Anis", "" ], [ "Omri", "Mohamed Nazih", "" ], [ "Mahjoub", "Mohamed Ali", "" ], [ "Garrouch", "Kamel", "" ] ]
TITLE: Mouse Movement and Probabilistic Graphical Models Based E-Learning Activity Recognition Improvement Possibilistic Model ABSTRACT: Automatically recognizing the e-learning activities is an important task for improving the online learning process. Probabilistic graphical models such as hidden Markov models and conditional random fields have been successfully used in order to identify a Web users activity. For such models, the sequences of observation are crucial for training and inference processes. Despite the efficiency of these probabilistic graphical models in segmenting and labeling stochastic sequences, their performance is adversely affected by the imperfect quality of data used for the construction of sequences of observation. In this paper, a formalism of the possibilistic theory will be used in order to propose a new approach for observation sequences preparation. The eminent contribution of our approach is to evaluate the effect of possibilistic reasoning during the generation of observation sequences on the effectiveness of hidden Markov models and conditional random fields models. Using a dataset containing 51 real manipulations related to three types of learners tasks, the preliminary experiments demonstrate that the sequences of observation obtained based on possibilistic reasoning significantly improve the performance of hidden Marvov models and conditional random fields models in the automatic recognition of the e-learning activities.
no_new_dataset
0.914444
1608.02676
Krishna Kumar Singh
Krishna Kumar Singh and Yong Jae Lee
End-to-End Localization and Ranking for Relative Attributes
Appears in European Conference on Computer Vision (ECCV), 2016
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose an end-to-end deep convolutional network to simultaneously localize and rank relative visual attributes, given only weakly-supervised pairwise image comparisons. Unlike previous methods, our network jointly learns the attribute's features, localization, and ranker. The localization module of our network discovers the most informative image region for the attribute, which is then used by the ranking module to learn a ranking model of the attribute. Our end-to-end framework also significantly speeds up processing and is much faster than previous methods. We show state-of-the-art ranking results on various relative attribute datasets, and our qualitative localization results clearly demonstrate our network's ability to learn meaningful image patches.
[ { "version": "v1", "created": "Tue, 9 Aug 2016 02:19:37 GMT" } ]
2016-08-10T00:00:00
[ [ "Singh", "Krishna Kumar", "" ], [ "Lee", "Yong Jae", "" ] ]
TITLE: End-to-End Localization and Ranking for Relative Attributes ABSTRACT: We propose an end-to-end deep convolutional network to simultaneously localize and rank relative visual attributes, given only weakly-supervised pairwise image comparisons. Unlike previous methods, our network jointly learns the attribute's features, localization, and ranker. The localization module of our network discovers the most informative image region for the attribute, which is then used by the ranking module to learn a ranking model of the attribute. Our end-to-end framework also significantly speeds up processing and is much faster than previous methods. We show state-of-the-art ranking results on various relative attribute datasets, and our qualitative localization results clearly demonstrate our network's ability to learn meaningful image patches.
no_new_dataset
0.954816
1608.02778
Ke Yu
Ke Yu, Chao Dong, Chen Change Loy, Xiaoou Tang
Deep Convolution Networks for Compression Artifacts Reduction
13 pages, 19 figures, an extension of our ICCV 2015 paper
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Lossy compression introduces complex compression artifacts, particularly blocking artifacts, ringing effects and blurring. Existing algorithms either focus on removing blocking artifacts and produce blurred output, or restore sharpened images that are accompanied with ringing effects. Inspired by the success of deep convolutional networks (DCN) on superresolution, we formulate a compact and efficient network for seamless attenuation of different compression artifacts. To meet the speed requirement of real-world applications, we further accelerate the proposed baseline model by layer decomposition and joint use of large-stride convolutional and deconvolutional layers. This also leads to a more general CNN framework that has a close relationship with the conventional Multi-Layer Perceptron (MLP). Finally, the modified network achieves a speed up of 7.5 times with almost no performance loss compared to the baseline model. We also demonstrate that a deeper model can be effectively trained with features learned in a shallow network. Following a similar "easy to hard" idea, we systematically investigate three practical transfer settings and show the effectiveness of transfer learning in low-level vision problems. Our method shows superior performance than the state-of-the-art methods both on benchmark datasets and a real-world use case.
[ { "version": "v1", "created": "Tue, 9 Aug 2016 12:11:51 GMT" } ]
2016-08-10T00:00:00
[ [ "Yu", "Ke", "" ], [ "Dong", "Chao", "" ], [ "Loy", "Chen Change", "" ], [ "Tang", "Xiaoou", "" ] ]
TITLE: Deep Convolution Networks for Compression Artifacts Reduction ABSTRACT: Lossy compression introduces complex compression artifacts, particularly blocking artifacts, ringing effects and blurring. Existing algorithms either focus on removing blocking artifacts and produce blurred output, or restore sharpened images that are accompanied with ringing effects. Inspired by the success of deep convolutional networks (DCN) on superresolution, we formulate a compact and efficient network for seamless attenuation of different compression artifacts. To meet the speed requirement of real-world applications, we further accelerate the proposed baseline model by layer decomposition and joint use of large-stride convolutional and deconvolutional layers. This also leads to a more general CNN framework that has a close relationship with the conventional Multi-Layer Perceptron (MLP). Finally, the modified network achieves a speed up of 7.5 times with almost no performance loss compared to the baseline model. We also demonstrate that a deeper model can be effectively trained with features learned in a shallow network. Following a similar "easy to hard" idea, we systematically investigate three practical transfer settings and show the effectiveness of transfer learning in low-level vision problems. Our method shows superior performance than the state-of-the-art methods both on benchmark datasets and a real-world use case.
no_new_dataset
0.948489
1608.02797
Sharon Lee
Sharon X Lee, Kaleb L Leemaqz, Geoffrey J McLachlan
A block EM algorithm for multivariate skew normal and skew t-mixture models
null
null
null
null
stat.CO cs.DC
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Finite mixtures of skew distributions provide a flexible tool for modelling heterogeneous data with asymmetric distributional features. However, parameter estimation via the Expectation-Maximization (EM) algorithm can become very time-consuming due to the complicated expressions involved in the E-step that are numerically expensive to evaluate. A more time-efficient implementation of the EM algorithm was recently proposed which allows each component of the mixture model to be evaluated in parallel. In this paper, we develop a block implementation of the EM algorithm that facilitates the calculations in the E- and M-steps to be spread across a larger number of threads. We focus on the fitting of finite mixtures of multivariate skew normal and skew t-distributions, and show that both the E- and M-steps in the EM algorithm can be modified to allow the data to be split into blocks. The approach can be easily implemented for use by multicore and multi-processor machines. It can also be applied concurrently with the recently proposed multithreaded EM algorithm to achieve further reduction in computation time. The improvement in time performance is illustrated on some real datasets.
[ { "version": "v1", "created": "Tue, 9 Aug 2016 13:28:38 GMT" } ]
2016-08-10T00:00:00
[ [ "Lee", "Sharon X", "" ], [ "Leemaqz", "Kaleb L", "" ], [ "McLachlan", "Geoffrey J", "" ] ]
TITLE: A block EM algorithm for multivariate skew normal and skew t-mixture models ABSTRACT: Finite mixtures of skew distributions provide a flexible tool for modelling heterogeneous data with asymmetric distributional features. However, parameter estimation via the Expectation-Maximization (EM) algorithm can become very time-consuming due to the complicated expressions involved in the E-step that are numerically expensive to evaluate. A more time-efficient implementation of the EM algorithm was recently proposed which allows each component of the mixture model to be evaluated in parallel. In this paper, we develop a block implementation of the EM algorithm that facilitates the calculations in the E- and M-steps to be spread across a larger number of threads. We focus on the fitting of finite mixtures of multivariate skew normal and skew t-distributions, and show that both the E- and M-steps in the EM algorithm can be modified to allow the data to be split into blocks. The approach can be easily implemented for use by multicore and multi-processor machines. It can also be applied concurrently with the recently proposed multithreaded EM algorithm to achieve further reduction in computation time. The improvement in time performance is illustrated on some real datasets.
no_new_dataset
0.945601
1608.02858
Jan Drchal
Jan Mrkos, Jan Drchal, Malcolm Egan, Michal Jakob
Liftago On-Demand Transport Dataset and Market Formation Algorithm Based on Machine Learning
9 pages, 2 figures, supplemental information for a journal paper
null
null
null
cs.AI cs.CY
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This document serves as a technical report for the analysis of on-demand transport dataset. Moreover we show how the dataset can be used to develop a market formation algorithm based on machine learning. Data used in this work comes from Liftago, a Prague based company which connects taxi drivers and customers through a smartphone app. The dataset is analysed from the machine-learning perspective: we give an overview of features available as well as results of feature ranking. Later we propose the SImple Data-driven MArket Formation (SIDMAF) algorithm which aims to improve a relevance while connecting customers with relevant drivers. We compare the heuristics currently used by Liftago with SIDMAF using two key performance indicators.
[ { "version": "v1", "created": "Tue, 9 Aug 2016 16:33:03 GMT" } ]
2016-08-10T00:00:00
[ [ "Mrkos", "Jan", "" ], [ "Drchal", "Jan", "" ], [ "Egan", "Malcolm", "" ], [ "Jakob", "Michal", "" ] ]
TITLE: Liftago On-Demand Transport Dataset and Market Formation Algorithm Based on Machine Learning ABSTRACT: This document serves as a technical report for the analysis of on-demand transport dataset. Moreover we show how the dataset can be used to develop a market formation algorithm based on machine learning. Data used in this work comes from Liftago, a Prague based company which connects taxi drivers and customers through a smartphone app. The dataset is analysed from the machine-learning perspective: we give an overview of features available as well as results of feature ranking. Later we propose the SImple Data-driven MArket Formation (SIDMAF) algorithm which aims to improve a relevance while connecting customers with relevant drivers. We compare the heuristics currently used by Liftago with SIDMAF using two key performance indicators.
no_new_dataset
0.951323
1608.02888
Ayad Ghany Ismaeel
Ayad Ghany Ismaeel, Dina Yousif Mikhail
Effective Data Mining Technique for Classification Cancers via Mutations in Gene using Neural Network
8 pages, 8 figures, 1 Table
(IJACSA) International Journal of Advanced Computer Science and Applications, Vol. 7, No. 7, 2016. Pages 69-76
10.14569/IJACSA.2016.070710
null
cs.LG
http://creativecommons.org/publicdomain/zero/1.0/
The prediction plays the important role in detecting efficient protection and therapy of cancer. The prediction of mutations in gene needs a diagnostic and classification, which is based on the whole database (big dataset), to reach sufficient accuracy results. Since the tumor suppressor P53 is approximately about fifty percentage of all human tumors because mutations that occur in the TP53 gene into the cells. So, this paper is applied on tumor p53, where the problem is there are several primitive databases (excel database) contain datasets of TP53 gene with its tumor protein p53, these databases are rich datasets that cover all mutations and cause diseases (cancers). But these Data Bases cannot reach to predict and diagnosis cancers, i.e. the big datasets have not efficient Data Mining method, which can predict, diagnosis the mutation, and classify the cancer of patient. The goal of this paper to reach a Data Mining technique, that employs neural network, which bases on the big datasets. Also, offers friendly predictions, flexible, and effective classified cancers, in order to overcome the previous techniques drawbacks. This proposed technique is done by using two approaches, first, bioinformatics techniques by using BLAST, CLUSTALW, etc, in order to know if there are malignant mutations or not. The second, data mining by using neural network; it is selected (12) out of (53) TP53 gene database fields. To clarify, one of these 12 fields (gene location field) did not exists in TP53 gene database; therefore, it is added to the database of TP53 gene in training and testing back propagation algorithm, in order to classify specifically the types of cancers. Feed Forward Back Propagation supports this Data Mining method with data training rate (1) and Mean Square Error (MSE) (0.00000000000001). This effective technique allows in a quick, accurate and easy way to classify the type of cancer.
[ { "version": "v1", "created": "Sat, 6 Aug 2016 12:48:40 GMT" } ]
2016-08-10T00:00:00
[ [ "Ismaeel", "Ayad Ghany", "" ], [ "Mikhail", "Dina Yousif", "" ] ]
TITLE: Effective Data Mining Technique for Classification Cancers via Mutations in Gene using Neural Network ABSTRACT: The prediction plays the important role in detecting efficient protection and therapy of cancer. The prediction of mutations in gene needs a diagnostic and classification, which is based on the whole database (big dataset), to reach sufficient accuracy results. Since the tumor suppressor P53 is approximately about fifty percentage of all human tumors because mutations that occur in the TP53 gene into the cells. So, this paper is applied on tumor p53, where the problem is there are several primitive databases (excel database) contain datasets of TP53 gene with its tumor protein p53, these databases are rich datasets that cover all mutations and cause diseases (cancers). But these Data Bases cannot reach to predict and diagnosis cancers, i.e. the big datasets have not efficient Data Mining method, which can predict, diagnosis the mutation, and classify the cancer of patient. The goal of this paper to reach a Data Mining technique, that employs neural network, which bases on the big datasets. Also, offers friendly predictions, flexible, and effective classified cancers, in order to overcome the previous techniques drawbacks. This proposed technique is done by using two approaches, first, bioinformatics techniques by using BLAST, CLUSTALW, etc, in order to know if there are malignant mutations or not. The second, data mining by using neural network; it is selected (12) out of (53) TP53 gene database fields. To clarify, one of these 12 fields (gene location field) did not exists in TP53 gene database; therefore, it is added to the database of TP53 gene in training and testing back propagation algorithm, in order to classify specifically the types of cancers. Feed Forward Back Propagation supports this Data Mining method with data training rate (1) and Mean Square Error (MSE) (0.00000000000001). This effective technique allows in a quick, accurate and easy way to classify the type of cancer.
no_new_dataset
0.944944
1506.03475
Yuqing Hou
Yuqing Hou, Zhouchen Lin
Image Tag Completion and Refinement by Subspace Clustering and Matrix Completion
This paper has been withdrawn by the author due to a error in the model formulation
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Tag-based image retrieval (TBIR) has drawn much attention in recent years due to the explosive amount of digital images and crowdsourcing tags. However, the TBIR applications still suffer from the deficient and inaccurate tags provided by users. Inspired by the subspace clustering methods, we formulate the tag completion problem in a subspace clustering model which assumes that images are sampled from subspaces, and complete the tags using the state-of-the-art Low Rank Representation (LRR) method. And we propose a matrix completion algorithm to further refine the tags. Our empirical results on multiple benchmark datasets for image annotation show that the proposed algorithm outperforms state-of-the-art approaches when handling missing and noisy tags.
[ { "version": "v1", "created": "Wed, 10 Jun 2015 20:42:50 GMT" }, { "version": "v2", "created": "Mon, 8 Aug 2016 02:14:37 GMT" } ]
2016-08-09T00:00:00
[ [ "Hou", "Yuqing", "" ], [ "Lin", "Zhouchen", "" ] ]
TITLE: Image Tag Completion and Refinement by Subspace Clustering and Matrix Completion ABSTRACT: Tag-based image retrieval (TBIR) has drawn much attention in recent years due to the explosive amount of digital images and crowdsourcing tags. However, the TBIR applications still suffer from the deficient and inaccurate tags provided by users. Inspired by the subspace clustering methods, we formulate the tag completion problem in a subspace clustering model which assumes that images are sampled from subspaces, and complete the tags using the state-of-the-art Low Rank Representation (LRR) method. And we propose a matrix completion algorithm to further refine the tags. Our empirical results on multiple benchmark datasets for image annotation show that the proposed algorithm outperforms state-of-the-art approaches when handling missing and noisy tags.
no_new_dataset
0.947284
1508.07468
Yuqing Hou
Yuqing Hou
Image Annotation Incorporating Low-Rankness, Tag and Visual Correlation and Inhomogeneous Errors
This paper has been withdrawn by the author to update more experiments and some errors in the algorithm
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Tag-based image retrieval (TBIR) has drawn much attention in recent years due to the explosive amount of digital images and crowdsourcing tags. However, TBIR is still suffering from the incomplete and inaccurate tags provided by users, posing a great challenge for tag-based image management applications. In this work, we proposed a novel method for image annotation, incorporating several priors: Low-Rankness, Tag and Visual Correlation and Inhomogeneous Errors. Highly representative CNN feature vectors are adopt to model the tag-visual correlation and narrow the semantic gap. And we extract word vectors for tags to measure similarity between tags in the semantic level, which is more accurate than traditional frequency-based or graph-based methods. We utilize the accelerated proximal gradient (APG) method to solve our model efficiently. Extensive experiments conducted on multiple benchmark datasets demonstrate the effectiveness and robustness of the proposed method.
[ { "version": "v1", "created": "Sat, 29 Aug 2015 15:47:20 GMT" }, { "version": "v2", "created": "Tue, 1 Mar 2016 04:43:51 GMT" }, { "version": "v3", "created": "Mon, 8 Aug 2016 02:15:36 GMT" } ]
2016-08-09T00:00:00
[ [ "Hou", "Yuqing", "" ] ]
TITLE: Image Annotation Incorporating Low-Rankness, Tag and Visual Correlation and Inhomogeneous Errors ABSTRACT: Tag-based image retrieval (TBIR) has drawn much attention in recent years due to the explosive amount of digital images and crowdsourcing tags. However, TBIR is still suffering from the incomplete and inaccurate tags provided by users, posing a great challenge for tag-based image management applications. In this work, we proposed a novel method for image annotation, incorporating several priors: Low-Rankness, Tag and Visual Correlation and Inhomogeneous Errors. Highly representative CNN feature vectors are adopt to model the tag-visual correlation and narrow the semantic gap. And we extract word vectors for tags to measure similarity between tags in the semantic level, which is more accurate than traditional frequency-based or graph-based methods. We utilize the accelerated proximal gradient (APG) method to solve our model efficiently. Extensive experiments conducted on multiple benchmark datasets demonstrate the effectiveness and robustness of the proposed method.
no_new_dataset
0.953232
1510.05237
Vijay Gadepally
Brendan Gavin and Vijay Gadepally and Jeremy Kepner
Large Enforced Sparse Non-Negative Matrix Factorization
9 pages
null
10.1109/IPDPSW.2016.58
null
cs.LG cs.NA cs.SI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Non-negative matrix factorization (NMF) is a common method for generating topic models from text data. NMF is widely accepted for producing good results despite its relative simplicity of implementation and ease of computation. One challenge with applying NMF to large datasets is that intermediate matrix products often become dense, stressing the memory and compute elements of a system. In this article, we investigate a simple but powerful modification of a common NMF algorithm that enforces the generation of sparse intermediate and output matrices. This method enables the application of NMF to large datasets through improved memory and compute performance. Further, we demonstrate empirically that this method of enforcing sparsity in the NMF either preserves or improves both the accuracy of the resulting topic model and the convergence rate of the underlying algorithm.
[ { "version": "v1", "created": "Sun, 18 Oct 2015 12:53:38 GMT" } ]
2016-08-09T00:00:00
[ [ "Gavin", "Brendan", "" ], [ "Gadepally", "Vijay", "" ], [ "Kepner", "Jeremy", "" ] ]
TITLE: Large Enforced Sparse Non-Negative Matrix Factorization ABSTRACT: Non-negative matrix factorization (NMF) is a common method for generating topic models from text data. NMF is widely accepted for producing good results despite its relative simplicity of implementation and ease of computation. One challenge with applying NMF to large datasets is that intermediate matrix products often become dense, stressing the memory and compute elements of a system. In this article, we investigate a simple but powerful modification of a common NMF algorithm that enforces the generation of sparse intermediate and output matrices. This method enables the application of NMF to large datasets through improved memory and compute performance. Further, we demonstrate empirically that this method of enforcing sparsity in the NMF either preserves or improves both the accuracy of the resulting topic model and the convergence rate of the underlying algorithm.
no_new_dataset
0.94545