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1611.00889
Kasra Khosoussi
Kasra Khosoussi, Gaurav S. Sukhatme, Shoudong Huang, Gamini Dissanayake
Designing Sparse Reliable Pose-Graph SLAM: A Graph-Theoretic Approach
WAFR 2016
null
null
null
cs.RO cs.DS
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we aim to design sparse D-optimal (determinantoptimal) pose-graph SLAM problems through the synthesis of sparse graphs with the maximum weighted number of spanning trees. Characterizing graphs with the maximum number of spanning trees is an open problem in general. To tackle this problem, several new theoretical results are established in this paper, including the monotone log-submodularity of the weighted number of spanning trees. By exploiting these structures, we design a complementary pair of near-optimal efficient approximation algorithms with provable guarantees. Our theoretical results are validated using random graphs and a publicly available pose-graph SLAM dataset.
[ { "version": "v1", "created": "Thu, 3 Nov 2016 05:52:37 GMT" } ]
2016-11-04T00:00:00
[ [ "Khosoussi", "Kasra", "" ], [ "Sukhatme", "Gaurav S.", "" ], [ "Huang", "Shoudong", "" ], [ "Dissanayake", "Gamini", "" ] ]
TITLE: Designing Sparse Reliable Pose-Graph SLAM: A Graph-Theoretic Approach ABSTRACT: In this paper, we aim to design sparse D-optimal (determinantoptimal) pose-graph SLAM problems through the synthesis of sparse graphs with the maximum weighted number of spanning trees. Characterizing graphs with the maximum number of spanning trees is an open problem in general. To tackle this problem, several new theoretical results are established in this paper, including the monotone log-submodularity of the weighted number of spanning trees. By exploiting these structures, we design a complementary pair of near-optimal efficient approximation algorithms with provable guarantees. Our theoretical results are validated using random graphs and a publicly available pose-graph SLAM dataset.
new_dataset
0.932883
1506.05532
Salman Khan Mr.
Munawar Hayat, Salman H. Khan, Mohammed Bennamoun, Senjian An
A Spatial Layout and Scale Invariant Feature Representation for Indoor Scene Classification
null
null
10.1109/TIP.2016.2599292
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Unlike standard object classification, where the image to be classified contains one or multiple instances of the same object, indoor scene classification is quite different since the image consists of multiple distinct objects. Further, these objects can be of varying sizes and are present across numerous spatial locations in different layouts. For automatic indoor scene categorization, large scale spatial layout deformations and scale variations are therefore two major challenges and the design of rich feature descriptors which are robust to these challenges is still an open problem. This paper introduces a new learnable feature descriptor called "spatial layout and scale invariant convolutional activations" to deal with these challenges. For this purpose, a new Convolutional Neural Network architecture is designed which incorporates a novel 'Spatially Unstructured' layer to introduce robustness against spatial layout deformations. To achieve scale invariance, we present a pyramidal image representation. For feasible training of the proposed network for images of indoor scenes, the paper proposes a new methodology which efficiently adapts a trained network model (on a large scale data) for our task with only a limited amount of available training data. Compared with existing state of the art, the proposed approach achieves a relative performance improvement of 3.2%, 3.8%, 7.0%, 11.9% and 2.1% on MIT-67, Scene-15, Sports-8, Graz-02 and NYU datasets respectively.
[ { "version": "v1", "created": "Thu, 18 Jun 2015 02:11:37 GMT" }, { "version": "v2", "created": "Fri, 14 Aug 2015 04:01:11 GMT" } ]
2016-11-03T00:00:00
[ [ "Hayat", "Munawar", "" ], [ "Khan", "Salman H.", "" ], [ "Bennamoun", "Mohammed", "" ], [ "An", "Senjian", "" ] ]
TITLE: A Spatial Layout and Scale Invariant Feature Representation for Indoor Scene Classification ABSTRACT: Unlike standard object classification, where the image to be classified contains one or multiple instances of the same object, indoor scene classification is quite different since the image consists of multiple distinct objects. Further, these objects can be of varying sizes and are present across numerous spatial locations in different layouts. For automatic indoor scene categorization, large scale spatial layout deformations and scale variations are therefore two major challenges and the design of rich feature descriptors which are robust to these challenges is still an open problem. This paper introduces a new learnable feature descriptor called "spatial layout and scale invariant convolutional activations" to deal with these challenges. For this purpose, a new Convolutional Neural Network architecture is designed which incorporates a novel 'Spatially Unstructured' layer to introduce robustness against spatial layout deformations. To achieve scale invariance, we present a pyramidal image representation. For feasible training of the proposed network for images of indoor scenes, the paper proposes a new methodology which efficiently adapts a trained network model (on a large scale data) for our task with only a limited amount of available training data. Compared with existing state of the art, the proposed approach achieves a relative performance improvement of 3.2%, 3.8%, 7.0%, 11.9% and 2.1% on MIT-67, Scene-15, Sports-8, Graz-02 and NYU datasets respectively.
no_new_dataset
0.950595
1511.08058
Yanwei Pang
Jiale Cao, Yanwei Pang, and Xuelong Li
Pedestrian Detection Inspired by Appearance Constancy and Shape Symmetry
9 pages,17 figures
null
10.1109/TIP.2016.2609807
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The discrimination and simplicity of features are very important for effective and efficient pedestrian detection. However, most state-of-the-art methods are unable to achieve good tradeoff between accuracy and efficiency. Inspired by some simple inherent attributes of pedestrians (i.e., appearance constancy and shape symmetry), we propose two new types of non-neighboring features (NNF): side-inner difference features (SIDF) and symmetrical similarity features (SSF). SIDF can characterize the difference between the background and pedestrian and the difference between the pedestrian contour and its inner part. SSF can capture the symmetrical similarity of pedestrian shape. However, it's difficult for neighboring features to have such above characterization abilities. Finally, we propose to combine both non-neighboring and neighboring features for pedestrian detection. It's found that non-neighboring features can further decrease the average miss rate by 4.44%. Experimental results on INRIA and Caltech pedestrian datasets demonstrate the effectiveness and efficiency of the proposed method. Compared to the state-of-the-art methods without using CNN, our method achieves the best detection performance on Caltech, outperforming the second best method (i.e., Checkboards) by 1.63%.
[ { "version": "v1", "created": "Wed, 25 Nov 2015 13:49:13 GMT" } ]
2016-11-03T00:00:00
[ [ "Cao", "Jiale", "" ], [ "Pang", "Yanwei", "" ], [ "Li", "Xuelong", "" ] ]
TITLE: Pedestrian Detection Inspired by Appearance Constancy and Shape Symmetry ABSTRACT: The discrimination and simplicity of features are very important for effective and efficient pedestrian detection. However, most state-of-the-art methods are unable to achieve good tradeoff between accuracy and efficiency. Inspired by some simple inherent attributes of pedestrians (i.e., appearance constancy and shape symmetry), we propose two new types of non-neighboring features (NNF): side-inner difference features (SIDF) and symmetrical similarity features (SSF). SIDF can characterize the difference between the background and pedestrian and the difference between the pedestrian contour and its inner part. SSF can capture the symmetrical similarity of pedestrian shape. However, it's difficult for neighboring features to have such above characterization abilities. Finally, we propose to combine both non-neighboring and neighboring features for pedestrian detection. It's found that non-neighboring features can further decrease the average miss rate by 4.44%. Experimental results on INRIA and Caltech pedestrian datasets demonstrate the effectiveness and efficiency of the proposed method. Compared to the state-of-the-art methods without using CNN, our method achieves the best detection performance on Caltech, outperforming the second best method (i.e., Checkboards) by 1.63%.
no_new_dataset
0.946843
1606.03757
Brendon Brewer
Brendon J. Brewer and Daniel Foreman-Mackey
DNest4: Diffusive Nested Sampling in C++ and Python
Submitted. 33 pages, 9 figures. v2 removed a duplicated figure, v3 added a comparison to other packages, v4 fixed a few minor issues
null
null
null
stat.CO astro-ph.IM physics.data-an
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In probabilistic (Bayesian) inferences, we typically want to compute properties of the posterior distribution, describing knowledge of unknown quantities in the context of a particular dataset and the assumed prior information. The marginal likelihood, also known as the "evidence", is a key quantity in Bayesian model selection. The Diffusive Nested Sampling algorithm, a variant of Nested Sampling, is a powerful tool for generating posterior samples and estimating marginal likelihoods. It is effective at solving complex problems including many where the posterior distribution is multimodal or has strong dependencies between variables. DNest4 is an open source (MIT licensed), multi-threaded implementation of this algorithm in C++11, along with associated utilities including: i) RJObject, a class template for finite mixture models, (ii) A Python package allowing basic use without C++ coding, and iii) Experimental support for models implemented in Julia. In this paper we demonstrate DNest4 usage through examples including simple Bayesian data analysis, finite mixture models, and Approximate Bayesian Computation.
[ { "version": "v1", "created": "Sun, 12 Jun 2016 19:21:30 GMT" }, { "version": "v2", "created": "Tue, 14 Jun 2016 00:57:29 GMT" }, { "version": "v3", "created": "Tue, 26 Jul 2016 02:22:54 GMT" }, { "version": "v4", "created": "Wed, 2 Nov 2016 01:15:31 GMT" } ]
2016-11-03T00:00:00
[ [ "Brewer", "Brendon J.", "" ], [ "Foreman-Mackey", "Daniel", "" ] ]
TITLE: DNest4: Diffusive Nested Sampling in C++ and Python ABSTRACT: In probabilistic (Bayesian) inferences, we typically want to compute properties of the posterior distribution, describing knowledge of unknown quantities in the context of a particular dataset and the assumed prior information. The marginal likelihood, also known as the "evidence", is a key quantity in Bayesian model selection. The Diffusive Nested Sampling algorithm, a variant of Nested Sampling, is a powerful tool for generating posterior samples and estimating marginal likelihoods. It is effective at solving complex problems including many where the posterior distribution is multimodal or has strong dependencies between variables. DNest4 is an open source (MIT licensed), multi-threaded implementation of this algorithm in C++11, along with associated utilities including: i) RJObject, a class template for finite mixture models, (ii) A Python package allowing basic use without C++ coding, and iii) Experimental support for models implemented in Julia. In this paper we demonstrate DNest4 usage through examples including simple Bayesian data analysis, finite mixture models, and Approximate Bayesian Computation.
no_new_dataset
0.949902
1607.08811
Pedro Herruzo
Pedro Herruzo, Marc Bola\~nos and Petia Radeva
Can a CNN Recognize Catalan Diet?
9 pages, 6 figures, 6 tables
null
10.1063/1.4964956
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Nowadays, we can find several diseases related to the unhealthy diet habits of the population, such as diabetes, obesity, anemia, bulimia and anorexia. In many cases, these diseases are related to the food consumption of people. Mediterranean diet is scientifically known as a healthy diet that helps to prevent many metabolic diseases. In particular, our work focuses on the recognition of Mediterranean food and dishes. The development of this methodology would allow to analise the daily habits of users with wearable cameras, within the topic of lifelogging. By using automatic mechanisms we could build an objective tool for the analysis of the patient's behaviour, allowing specialists to discover unhealthy food patterns and understand the user's lifestyle. With the aim to automatically recognize a complete diet, we introduce a challenging multi-labeled dataset related to Mediterranean diet called FoodCAT. The first type of label provided consists of 115 food classes with an average of 400 images per dish, and the second one consists of 12 food categories with an average of 3800 pictures per class. This dataset will serve as a basis for the development of automatic diet recognition. In this context, deep learning and more specifically, Convolutional Neural Networks (CNNs), currently are state-of-the-art methods for automatic food recognition. In our work, we compare several architectures for image classification, with the purpose of diet recognition. Applying the best model for recognising food categories, we achieve a top-1 accuracy of 72.29\%, and top-5 of 97.07\%. In a complete diet recognition of dishes from Mediterranean diet, enlarged with the Food-101 dataset for international dishes recognition, we achieve a top-1 accuracy of 68.07\%, and top-5 of 89.53\%, for a total of 115+101 food classes.
[ { "version": "v1", "created": "Fri, 29 Jul 2016 13:55:21 GMT" } ]
2016-11-03T00:00:00
[ [ "Herruzo", "Pedro", "" ], [ "Bolaños", "Marc", "" ], [ "Radeva", "Petia", "" ] ]
TITLE: Can a CNN Recognize Catalan Diet? ABSTRACT: Nowadays, we can find several diseases related to the unhealthy diet habits of the population, such as diabetes, obesity, anemia, bulimia and anorexia. In many cases, these diseases are related to the food consumption of people. Mediterranean diet is scientifically known as a healthy diet that helps to prevent many metabolic diseases. In particular, our work focuses on the recognition of Mediterranean food and dishes. The development of this methodology would allow to analise the daily habits of users with wearable cameras, within the topic of lifelogging. By using automatic mechanisms we could build an objective tool for the analysis of the patient's behaviour, allowing specialists to discover unhealthy food patterns and understand the user's lifestyle. With the aim to automatically recognize a complete diet, we introduce a challenging multi-labeled dataset related to Mediterranean diet called FoodCAT. The first type of label provided consists of 115 food classes with an average of 400 images per dish, and the second one consists of 12 food categories with an average of 3800 pictures per class. This dataset will serve as a basis for the development of automatic diet recognition. In this context, deep learning and more specifically, Convolutional Neural Networks (CNNs), currently are state-of-the-art methods for automatic food recognition. In our work, we compare several architectures for image classification, with the purpose of diet recognition. Applying the best model for recognising food categories, we achieve a top-1 accuracy of 72.29\%, and top-5 of 97.07\%. In a complete diet recognition of dishes from Mediterranean diet, enlarged with the Food-101 dataset for international dishes recognition, we achieve a top-1 accuracy of 68.07\%, and top-5 of 89.53\%, for a total of 115+101 food classes.
new_dataset
0.967287
1609.02077
Guanbin Li
Guanbin Li and Yizhou Yu
Visual Saliency Detection Based on Multiscale Deep CNN Features
Accepted for publication in IEEE Transactions on Image Processing
null
10.1109/TIP.2016.2602079
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Visual saliency is a fundamental problem in both cognitive and computational sciences, including computer vision. In this paper, we discover that a high-quality visual saliency model can be learned from multiscale features extracted using deep convolutional neural networks (CNNs), which have had many successes in visual recognition tasks. For learning such saliency models, we introduce a neural network architecture, which has fully connected layers on top of CNNs responsible for feature extraction at three different scales. The penultimate layer of our neural network has been confirmed to be a discriminative high-level feature vector for saliency detection, which we call deep contrast feature. To generate a more robust feature, we integrate handcrafted low-level features with our deep contrast feature. To promote further research and evaluation of visual saliency models, we also construct a new large database of 4447 challenging images and their pixelwise saliency annotations. Experimental results demonstrate that our proposed method is capable of achieving state-of-the-art performance on all public benchmarks, improving the F- measure by 6.12% and 10.0% respectively on the DUT-OMRON dataset and our new dataset (HKU-IS), and lowering the mean absolute error by 9% and 35.3% respectively on these two datasets.
[ { "version": "v1", "created": "Wed, 7 Sep 2016 17:13:16 GMT" } ]
2016-11-03T00:00:00
[ [ "Li", "Guanbin", "" ], [ "Yu", "Yizhou", "" ] ]
TITLE: Visual Saliency Detection Based on Multiscale Deep CNN Features ABSTRACT: Visual saliency is a fundamental problem in both cognitive and computational sciences, including computer vision. In this paper, we discover that a high-quality visual saliency model can be learned from multiscale features extracted using deep convolutional neural networks (CNNs), which have had many successes in visual recognition tasks. For learning such saliency models, we introduce a neural network architecture, which has fully connected layers on top of CNNs responsible for feature extraction at three different scales. The penultimate layer of our neural network has been confirmed to be a discriminative high-level feature vector for saliency detection, which we call deep contrast feature. To generate a more robust feature, we integrate handcrafted low-level features with our deep contrast feature. To promote further research and evaluation of visual saliency models, we also construct a new large database of 4447 challenging images and their pixelwise saliency annotations. Experimental results demonstrate that our proposed method is capable of achieving state-of-the-art performance on all public benchmarks, improving the F- measure by 6.12% and 10.0% respectively on the DUT-OMRON dataset and our new dataset (HKU-IS), and lowering the mean absolute error by 9% and 35.3% respectively on these two datasets.
new_dataset
0.955569
1610.07184
Soumitra Pal
Soumitra Pal, Tingyang Xu, Tianbao Yang, Sanguthevar Rajasekaran, Jinbo Bi
Hybrid-DCA: A Double Asynchronous Approach for Stochastic Dual Coordinate Ascent
null
null
null
null
cs.DC math.OC
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In prior works, stochastic dual coordinate ascent (SDCA) has been parallelized in a multi-core environment where the cores communicate through shared memory, or in a multi-processor distributed memory environment where the processors communicate through message passing. In this paper, we propose a hybrid SDCA framework for multi-core clusters, the most common high performance computing environment that consists of multiple nodes each having multiple cores and its own shared memory. We distribute data across nodes where each node solves a local problem in an asynchronous parallel fashion on its cores, and then the local updates are aggregated via an asynchronous across-node update scheme. The proposed double asynchronous method converges to a global solution for $L$-Lipschitz continuous loss functions, and at a linear convergence rate if a smooth convex loss function is used. Extensive empirical comparison has shown that our algorithm scales better than the best known shared-memory methods and runs faster than previous distributed-memory methods. Big datasets, such as one of 280 GB from the LIBSVM repository, cannot be accommodated on a single node and hence cannot be solved by a parallel algorithm. For such a dataset, our hybrid algorithm takes 30 seconds to achieve a duality gap of $10^{-6}$ on 16 nodes each using 8 cores, which is significantly faster than the best known distributed algorithms, such as CoCoA+, that take more than 300 seconds on 16 nodes.
[ { "version": "v1", "created": "Sun, 23 Oct 2016 15:17:43 GMT" }, { "version": "v2", "created": "Wed, 2 Nov 2016 17:50:50 GMT" } ]
2016-11-03T00:00:00
[ [ "Pal", "Soumitra", "" ], [ "Xu", "Tingyang", "" ], [ "Yang", "Tianbao", "" ], [ "Rajasekaran", "Sanguthevar", "" ], [ "Bi", "Jinbo", "" ] ]
TITLE: Hybrid-DCA: A Double Asynchronous Approach for Stochastic Dual Coordinate Ascent ABSTRACT: In prior works, stochastic dual coordinate ascent (SDCA) has been parallelized in a multi-core environment where the cores communicate through shared memory, or in a multi-processor distributed memory environment where the processors communicate through message passing. In this paper, we propose a hybrid SDCA framework for multi-core clusters, the most common high performance computing environment that consists of multiple nodes each having multiple cores and its own shared memory. We distribute data across nodes where each node solves a local problem in an asynchronous parallel fashion on its cores, and then the local updates are aggregated via an asynchronous across-node update scheme. The proposed double asynchronous method converges to a global solution for $L$-Lipschitz continuous loss functions, and at a linear convergence rate if a smooth convex loss function is used. Extensive empirical comparison has shown that our algorithm scales better than the best known shared-memory methods and runs faster than previous distributed-memory methods. Big datasets, such as one of 280 GB from the LIBSVM repository, cannot be accommodated on a single node and hence cannot be solved by a parallel algorithm. For such a dataset, our hybrid algorithm takes 30 seconds to achieve a duality gap of $10^{-6}$ on 16 nodes each using 8 cores, which is significantly faster than the best known distributed algorithms, such as CoCoA+, that take more than 300 seconds on 16 nodes.
no_new_dataset
0.944022
1610.09650
Bharat Sau
Bharat Bhusan Sau and Vineeth N. Balasubramanian
Deep Model Compression: Distilling Knowledge from Noisy Teachers
9 pages, 3 figures
null
null
null
cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The remarkable successes of deep learning models across various applications have resulted in the design of deeper networks that can solve complex problems. However, the increasing depth of such models also results in a higher storage and runtime complexity, which restricts the deployability of such very deep models on mobile and portable devices, which have limited storage and battery capacity. While many methods have been proposed for deep model compression in recent years, almost all of them have focused on reducing storage complexity. In this work, we extend the teacher-student framework for deep model compression, since it has the potential to address runtime and train time complexity too. We propose a simple methodology to include a noise-based regularizer while training the student from the teacher, which provides a healthy improvement in the performance of the student network. Our experiments on the CIFAR-10, SVHN and MNIST datasets show promising improvement, with the best performance on the CIFAR-10 dataset. We also conduct a comprehensive empirical evaluation of the proposed method under related settings on the CIFAR-10 dataset to show the promise of the proposed approach.
[ { "version": "v1", "created": "Sun, 30 Oct 2016 13:54:39 GMT" }, { "version": "v2", "created": "Wed, 2 Nov 2016 16:32:23 GMT" } ]
2016-11-03T00:00:00
[ [ "Sau", "Bharat Bhusan", "" ], [ "Balasubramanian", "Vineeth N.", "" ] ]
TITLE: Deep Model Compression: Distilling Knowledge from Noisy Teachers ABSTRACT: The remarkable successes of deep learning models across various applications have resulted in the design of deeper networks that can solve complex problems. However, the increasing depth of such models also results in a higher storage and runtime complexity, which restricts the deployability of such very deep models on mobile and portable devices, which have limited storage and battery capacity. While many methods have been proposed for deep model compression in recent years, almost all of them have focused on reducing storage complexity. In this work, we extend the teacher-student framework for deep model compression, since it has the potential to address runtime and train time complexity too. We propose a simple methodology to include a noise-based regularizer while training the student from the teacher, which provides a healthy improvement in the performance of the student network. Our experiments on the CIFAR-10, SVHN and MNIST datasets show promising improvement, with the best performance on the CIFAR-10 dataset. We also conduct a comprehensive empirical evaluation of the proposed method under related settings on the CIFAR-10 dataset to show the promise of the proposed approach.
no_new_dataset
0.944382
1610.09996
Yang Yu
Yang Yu, Wei Zhang, Kazi Hasan, Mo Yu, Bing Xiang, Bowen Zhou
End-to-End Answer Chunk Extraction and Ranking for Reading Comprehension
Submitted to AAAI
null
null
null
cs.CL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper proposes dynamic chunk reader (DCR), an end-to-end neural reading comprehension (RC) model that is able to extract and rank a set of answer candidates from a given document to answer questions. DCR is able to predict answers of variable lengths, whereas previous neural RC models primarily focused on predicting single tokens or entities. DCR encodes a document and an input question with recurrent neural networks, and then applies a word-by-word attention mechanism to acquire question-aware representations for the document, followed by the generation of chunk representations and a ranking module to propose the top-ranked chunk as the answer. Experimental results show that DCR achieves state-of-the-art exact match and F1 scores on the SQuAD dataset.
[ { "version": "v1", "created": "Mon, 31 Oct 2016 16:14:08 GMT" }, { "version": "v2", "created": "Wed, 2 Nov 2016 17:55:32 GMT" } ]
2016-11-03T00:00:00
[ [ "Yu", "Yang", "" ], [ "Zhang", "Wei", "" ], [ "Hasan", "Kazi", "" ], [ "Yu", "Mo", "" ], [ "Xiang", "Bing", "" ], [ "Zhou", "Bowen", "" ] ]
TITLE: End-to-End Answer Chunk Extraction and Ranking for Reading Comprehension ABSTRACT: This paper proposes dynamic chunk reader (DCR), an end-to-end neural reading comprehension (RC) model that is able to extract and rank a set of answer candidates from a given document to answer questions. DCR is able to predict answers of variable lengths, whereas previous neural RC models primarily focused on predicting single tokens or entities. DCR encodes a document and an input question with recurrent neural networks, and then applies a word-by-word attention mechanism to acquire question-aware representations for the document, followed by the generation of chunk representations and a ranking module to propose the top-ranked chunk as the answer. Experimental results show that DCR achieves state-of-the-art exact match and F1 scores on the SQuAD dataset.
no_new_dataset
0.950595
1611.00336
Andrew Wilson
Andrew Gordon Wilson, Zhiting Hu, Ruslan Salakhutdinov, Eric P. Xing
Stochastic Variational Deep Kernel Learning
13 pages, 6 tables, 3 figures. Appearing in NIPS 2016
null
null
null
stat.ML cs.LG stat.ME
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Deep kernel learning combines the non-parametric flexibility of kernel methods with the inductive biases of deep learning architectures. We propose a novel deep kernel learning model and stochastic variational inference procedure which generalizes deep kernel learning approaches to enable classification, multi-task learning, additive covariance structures, and stochastic gradient training. Specifically, we apply additive base kernels to subsets of output features from deep neural architectures, and jointly learn the parameters of the base kernels and deep network through a Gaussian process marginal likelihood objective. Within this framework, we derive an efficient form of stochastic variational inference which leverages local kernel interpolation, inducing points, and structure exploiting algebra. We show improved performance over stand alone deep networks, SVMs, and state of the art scalable Gaussian processes on several classification benchmarks, including an airline delay dataset containing 6 million training points, CIFAR, and ImageNet.
[ { "version": "v1", "created": "Tue, 1 Nov 2016 19:04:47 GMT" }, { "version": "v2", "created": "Wed, 2 Nov 2016 18:06:16 GMT" } ]
2016-11-03T00:00:00
[ [ "Wilson", "Andrew Gordon", "" ], [ "Hu", "Zhiting", "" ], [ "Salakhutdinov", "Ruslan", "" ], [ "Xing", "Eric P.", "" ] ]
TITLE: Stochastic Variational Deep Kernel Learning ABSTRACT: Deep kernel learning combines the non-parametric flexibility of kernel methods with the inductive biases of deep learning architectures. We propose a novel deep kernel learning model and stochastic variational inference procedure which generalizes deep kernel learning approaches to enable classification, multi-task learning, additive covariance structures, and stochastic gradient training. Specifically, we apply additive base kernels to subsets of output features from deep neural architectures, and jointly learn the parameters of the base kernels and deep network through a Gaussian process marginal likelihood objective. Within this framework, we derive an efficient form of stochastic variational inference which leverages local kernel interpolation, inducing points, and structure exploiting algebra. We show improved performance over stand alone deep networks, SVMs, and state of the art scalable Gaussian processes on several classification benchmarks, including an airline delay dataset containing 6 million training points, CIFAR, and ImageNet.
no_new_dataset
0.948489
1611.00379
Baptiste Caramiaux
Rebecca Fiebrink, Baptiste Caramiaux
The Machine Learning Algorithm as Creative Musical Tool
Pre-print to appear in the Oxford Handbook on Algorithmic Music. Oxford University Press
null
null
null
cs.HC cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Machine learning is the capacity of a computational system to learn structures from datasets in order to make predictions on newly seen data. Such an approach offers a significant advantage in music scenarios in which musicians can teach the system to learn an idiosyncratic style, or can break the rules to explore the system's capacity in unexpected ways. In this chapter we draw on music, machine learning, and human-computer interaction to elucidate an understanding of machine learning algorithms as creative tools for music and the sonic arts. We motivate a new understanding of learning algorithms as human-computer interfaces. We show that, like other interfaces, learning algorithms can be characterised by the ways their affordances intersect with goals of human users. We also argue that the nature of interaction between users and algorithms impacts the usability and usefulness of those algorithms in profound ways. This human-centred view of machine learning motivates our concluding discussion of what it means to employ machine learning as a creative tool.
[ { "version": "v1", "created": "Tue, 1 Nov 2016 20:35:46 GMT" } ]
2016-11-03T00:00:00
[ [ "Fiebrink", "Rebecca", "" ], [ "Caramiaux", "Baptiste", "" ] ]
TITLE: The Machine Learning Algorithm as Creative Musical Tool ABSTRACT: Machine learning is the capacity of a computational system to learn structures from datasets in order to make predictions on newly seen data. Such an approach offers a significant advantage in music scenarios in which musicians can teach the system to learn an idiosyncratic style, or can break the rules to explore the system's capacity in unexpected ways. In this chapter we draw on music, machine learning, and human-computer interaction to elucidate an understanding of machine learning algorithms as creative tools for music and the sonic arts. We motivate a new understanding of learning algorithms as human-computer interfaces. We show that, like other interfaces, learning algorithms can be characterised by the ways their affordances intersect with goals of human users. We also argue that the nature of interaction between users and algorithms impacts the usability and usefulness of those algorithms in profound ways. This human-centred view of machine learning motivates our concluding discussion of what it means to employ machine learning as a creative tool.
no_new_dataset
0.945551
1611.00423
Haoyu Zhang
Haoyu Zhang, Qin Zhang
Computing Skylines on Distributed Data
null
null
null
null
cs.DB cs.DS
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we study skyline queries in the distributed computational model, where we have $s$ remote sites and a central coordinator (the query node); each site holds a piece of data, and the coordinator wants to compute the skyline of the union of the $s$ datasets. The computation is in terms of rounds, and the goal is to minimize both the total communication cost and the round cost. Viewing data objects as points in the Euclidean space, we consider both the horizontal data partition case where each site holds a subset of points, and the vertical data partition case where each site holds one coordinate of all the points. We give a set of algorithms that have provable theoretical guarantees, and complement them with information theoretical lower bounds. We also demonstrate the superiority of our algorithms over existing heuristics by an extensive set of experiments on both synthetic and real world datasets.
[ { "version": "v1", "created": "Tue, 1 Nov 2016 23:41:03 GMT" } ]
2016-11-03T00:00:00
[ [ "Zhang", "Haoyu", "" ], [ "Zhang", "Qin", "" ] ]
TITLE: Computing Skylines on Distributed Data ABSTRACT: In this paper we study skyline queries in the distributed computational model, where we have $s$ remote sites and a central coordinator (the query node); each site holds a piece of data, and the coordinator wants to compute the skyline of the union of the $s$ datasets. The computation is in terms of rounds, and the goal is to minimize both the total communication cost and the round cost. Viewing data objects as points in the Euclidean space, we consider both the horizontal data partition case where each site holds a subset of points, and the vertical data partition case where each site holds one coordinate of all the points. We give a set of algorithms that have provable theoretical guarantees, and complement them with information theoretical lower bounds. We also demonstrate the superiority of our algorithms over existing heuristics by an extensive set of experiments on both synthetic and real world datasets.
no_new_dataset
0.948251
1611.00448
Hao Wang
Hao Wang, Xingjian Shi, Dit-Yan Yeung
Natural-Parameter Networks: A Class of Probabilistic Neural Networks
To appear at NIPS 2016
null
null
null
cs.LG cs.AI cs.CL cs.CV stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Neural networks (NN) have achieved state-of-the-art performance in various applications. Unfortunately in applications where training data is insufficient, they are often prone to overfitting. One effective way to alleviate this problem is to exploit the Bayesian approach by using Bayesian neural networks (BNN). Another shortcoming of NN is the lack of flexibility to customize different distributions for the weights and neurons according to the data, as is often done in probabilistic graphical models. To address these problems, we propose a class of probabilistic neural networks, dubbed natural-parameter networks (NPN), as a novel and lightweight Bayesian treatment of NN. NPN allows the usage of arbitrary exponential-family distributions to model the weights and neurons. Different from traditional NN and BNN, NPN takes distributions as input and goes through layers of transformation before producing distributions to match the target output distributions. As a Bayesian treatment, efficient backpropagation (BP) is performed to learn the natural parameters for the distributions over both the weights and neurons. The output distributions of each layer, as byproducts, may be used as second-order representations for the associated tasks such as link prediction. Experiments on real-world datasets show that NPN can achieve state-of-the-art performance.
[ { "version": "v1", "created": "Wed, 2 Nov 2016 02:32:05 GMT" } ]
2016-11-03T00:00:00
[ [ "Wang", "Hao", "" ], [ "Shi", "Xingjian", "" ], [ "Yeung", "Dit-Yan", "" ] ]
TITLE: Natural-Parameter Networks: A Class of Probabilistic Neural Networks ABSTRACT: Neural networks (NN) have achieved state-of-the-art performance in various applications. Unfortunately in applications where training data is insufficient, they are often prone to overfitting. One effective way to alleviate this problem is to exploit the Bayesian approach by using Bayesian neural networks (BNN). Another shortcoming of NN is the lack of flexibility to customize different distributions for the weights and neurons according to the data, as is often done in probabilistic graphical models. To address these problems, we propose a class of probabilistic neural networks, dubbed natural-parameter networks (NPN), as a novel and lightweight Bayesian treatment of NN. NPN allows the usage of arbitrary exponential-family distributions to model the weights and neurons. Different from traditional NN and BNN, NPN takes distributions as input and goes through layers of transformation before producing distributions to match the target output distributions. As a Bayesian treatment, efficient backpropagation (BP) is performed to learn the natural parameters for the distributions over both the weights and neurons. The output distributions of each layer, as byproducts, may be used as second-order representations for the associated tasks such as link prediction. Experiments on real-world datasets show that NPN can achieve state-of-the-art performance.
no_new_dataset
0.948442
1611.00454
Hao Wang
Hao Wang, Xingjian Shi, Dit-Yan Yeung
Collaborative Recurrent Autoencoder: Recommend while Learning to Fill in the Blanks
To appear at NIPS 2016
null
null
null
cs.LG cs.AI cs.CL cs.CV stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Hybrid methods that utilize both content and rating information are commonly used in many recommender systems. However, most of them use either handcrafted features or the bag-of-words representation as a surrogate for the content information but they are neither effective nor natural enough. To address this problem, we develop a collaborative recurrent autoencoder (CRAE) which is a denoising recurrent autoencoder (DRAE) that models the generation of content sequences in the collaborative filtering (CF) setting. The model generalizes recent advances in recurrent deep learning from i.i.d. input to non-i.i.d. (CF-based) input and provides a new denoising scheme along with a novel learnable pooling scheme for the recurrent autoencoder. To do this, we first develop a hierarchical Bayesian model for the DRAE and then generalize it to the CF setting. The synergy between denoising and CF enables CRAE to make accurate recommendations while learning to fill in the blanks in sequences. Experiments on real-world datasets from different domains (CiteULike and Netflix) show that, by jointly modeling the order-aware generation of sequences for the content information and performing CF for the ratings, CRAE is able to significantly outperform the state of the art on both the recommendation task based on ratings and the sequence generation task based on content information.
[ { "version": "v1", "created": "Wed, 2 Nov 2016 02:49:44 GMT" } ]
2016-11-03T00:00:00
[ [ "Wang", "Hao", "" ], [ "Shi", "Xingjian", "" ], [ "Yeung", "Dit-Yan", "" ] ]
TITLE: Collaborative Recurrent Autoencoder: Recommend while Learning to Fill in the Blanks ABSTRACT: Hybrid methods that utilize both content and rating information are commonly used in many recommender systems. However, most of them use either handcrafted features or the bag-of-words representation as a surrogate for the content information but they are neither effective nor natural enough. To address this problem, we develop a collaborative recurrent autoencoder (CRAE) which is a denoising recurrent autoencoder (DRAE) that models the generation of content sequences in the collaborative filtering (CF) setting. The model generalizes recent advances in recurrent deep learning from i.i.d. input to non-i.i.d. (CF-based) input and provides a new denoising scheme along with a novel learnable pooling scheme for the recurrent autoencoder. To do this, we first develop a hierarchical Bayesian model for the DRAE and then generalize it to the CF setting. The synergy between denoising and CF enables CRAE to make accurate recommendations while learning to fill in the blanks in sequences. Experiments on real-world datasets from different domains (CiteULike and Netflix) show that, by jointly modeling the order-aware generation of sequences for the content information and performing CF for the ratings, CRAE is able to significantly outperform the state of the art on both the recommendation task based on ratings and the sequence generation task based on content information.
no_new_dataset
0.951097
1611.00457
Bo Wang
Bo Wang, Yingjun Sun, Yuan Wang
Structure vs. Language: Investigating the Multi-factors of Asymmetric Opinions on Online Social Interrelationship with a Case Study
null
null
null
null
cs.SI cs.CL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Though current researches often study the properties of online social relationship from an objective view, we also need to understand individuals' subjective opinions on their interrelationships in social computing studies. Inspired by the theories from sociolinguistics, the latest work indicates that interactive language can reveal individuals' asymmetric opinions on their interrelationship. In this work, in order to explain the opinions' asymmetry on interrelationship with more latent factors, we extend the investigation from single relationship to the structural context in online social network. We analyze the correlation between interactive language features and the structural context of interrelationships. The structural context of vertex, edges and triangles in social network are considered. With statistical analysis on Enron email dataset, we find that individuals' opinions (measured by interactive language features) on their interrelationship are related to some of their important structural context in social network. This result can help us to understand and measure the individuals' opinions on their interrelationship with more intrinsic information.
[ { "version": "v1", "created": "Wed, 2 Nov 2016 03:11:10 GMT" } ]
2016-11-03T00:00:00
[ [ "Wang", "Bo", "" ], [ "Sun", "Yingjun", "" ], [ "Wang", "Yuan", "" ] ]
TITLE: Structure vs. Language: Investigating the Multi-factors of Asymmetric Opinions on Online Social Interrelationship with a Case Study ABSTRACT: Though current researches often study the properties of online social relationship from an objective view, we also need to understand individuals' subjective opinions on their interrelationships in social computing studies. Inspired by the theories from sociolinguistics, the latest work indicates that interactive language can reveal individuals' asymmetric opinions on their interrelationship. In this work, in order to explain the opinions' asymmetry on interrelationship with more latent factors, we extend the investigation from single relationship to the structural context in online social network. We analyze the correlation between interactive language features and the structural context of interrelationships. The structural context of vertex, edges and triangles in social network are considered. With statistical analysis on Enron email dataset, we find that individuals' opinions (measured by interactive language features) on their interrelationship are related to some of their important structural context in social network. This result can help us to understand and measure the individuals' opinions on their interrelationship with more intrinsic information.
no_new_dataset
0.941331
1611.00468
Xiao Chu
Xiao Chu, Wanli Ouyang, Hongsheng Li and Xiaogang Wang
CRF-CNN: Modeling Structured Information in Human Pose Estimation
NIPS
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Deep convolutional neural networks (CNN) have achieved great success. On the other hand, modeling structural information has been proved critical in many vision problems. It is of great interest to integrate them effectively. In a classical neural network, there is no message passing between neurons in the same layer. In this paper, we propose a CRF-CNN framework which can simultaneously model structural information in both output and hidden feature layers in a probabilistic way, and it is applied to human pose estimation. A message passing scheme is proposed, so that in various layers each body joint receives messages from all the others in an efficient way. Such message passing can be implemented with convolution between features maps in the same layer, and it is also integrated with feedforward propagation in neural networks. Finally, a neural network implementation of end-to-end learning CRF-CNN is provided. Its effectiveness is demonstrated through experiments on two benchmark datasets.
[ { "version": "v1", "created": "Wed, 2 Nov 2016 04:42:40 GMT" } ]
2016-11-03T00:00:00
[ [ "Chu", "Xiao", "" ], [ "Ouyang", "Wanli", "" ], [ "Li", "Hongsheng", "" ], [ "Wang", "Xiaogang", "" ] ]
TITLE: CRF-CNN: Modeling Structured Information in Human Pose Estimation ABSTRACT: Deep convolutional neural networks (CNN) have achieved great success. On the other hand, modeling structural information has been proved critical in many vision problems. It is of great interest to integrate them effectively. In a classical neural network, there is no message passing between neurons in the same layer. In this paper, we propose a CRF-CNN framework which can simultaneously model structural information in both output and hidden feature layers in a probabilistic way, and it is applied to human pose estimation. A message passing scheme is proposed, so that in various layers each body joint receives messages from all the others in an efficient way. Such message passing can be implemented with convolution between features maps in the same layer, and it is also integrated with feedforward propagation in neural networks. Finally, a neural network implementation of end-to-end learning CRF-CNN is provided. Its effectiveness is demonstrated through experiments on two benchmark datasets.
no_new_dataset
0.952838
1611.00472
Ameya Prabhu
Ameya Prabhu, Aditya Joshi, Manish Shrivastava and Vasudeva Varma
Towards Sub-Word Level Compositions for Sentiment Analysis of Hindi-English Code Mixed Text
Accepted paper at COLING 2016
null
null
null
cs.CL
http://creativecommons.org/licenses/by/4.0/
Sentiment analysis (SA) using code-mixed data from social media has several applications in opinion mining ranging from customer satisfaction to social campaign analysis in multilingual societies. Advances in this area are impeded by the lack of a suitable annotated dataset. We introduce a Hindi-English (Hi-En) code-mixed dataset for sentiment analysis and perform empirical analysis comparing the suitability and performance of various state-of-the-art SA methods in social media. In this paper, we introduce learning sub-word level representations in LSTM (Subword-LSTM) architecture instead of character-level or word-level representations. This linguistic prior in our architecture enables us to learn the information about sentiment value of important morphemes. This also seems to work well in highly noisy text containing misspellings as shown in our experiments which is demonstrated in morpheme-level feature maps learned by our model. Also, we hypothesize that encoding this linguistic prior in the Subword-LSTM architecture leads to the superior performance. Our system attains accuracy 4-5% greater than traditional approaches on our dataset, and also outperforms the available system for sentiment analysis in Hi-En code-mixed text by 18%.
[ { "version": "v1", "created": "Wed, 2 Nov 2016 05:23:53 GMT" } ]
2016-11-03T00:00:00
[ [ "Prabhu", "Ameya", "" ], [ "Joshi", "Aditya", "" ], [ "Shrivastava", "Manish", "" ], [ "Varma", "Vasudeva", "" ] ]
TITLE: Towards Sub-Word Level Compositions for Sentiment Analysis of Hindi-English Code Mixed Text ABSTRACT: Sentiment analysis (SA) using code-mixed data from social media has several applications in opinion mining ranging from customer satisfaction to social campaign analysis in multilingual societies. Advances in this area are impeded by the lack of a suitable annotated dataset. We introduce a Hindi-English (Hi-En) code-mixed dataset for sentiment analysis and perform empirical analysis comparing the suitability and performance of various state-of-the-art SA methods in social media. In this paper, we introduce learning sub-word level representations in LSTM (Subword-LSTM) architecture instead of character-level or word-level representations. This linguistic prior in our architecture enables us to learn the information about sentiment value of important morphemes. This also seems to work well in highly noisy text containing misspellings as shown in our experiments which is demonstrated in morpheme-level feature maps learned by our model. Also, we hypothesize that encoding this linguistic prior in the Subword-LSTM architecture leads to the superior performance. Our system attains accuracy 4-5% greater than traditional approaches on our dataset, and also outperforms the available system for sentiment analysis in Hi-En code-mixed text by 18%.
new_dataset
0.971047
1611.00549
Oliver Cliff
Oliver M. Cliff and Mikhail Prokopenko and Robert Fitch
Inferring Coupling of Distributed Dynamical Systems via Transfer Entropy
null
null
null
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work, we are interested in structure learning for a set of spatially distributed dynamical systems, where individual subsystems are coupled via latent variables and observed through a filter. We represent this model as a directed acyclic graph (DAG) that characterises the unidirectional coupling between subsystems. Standard approaches to structure learning are not applicable in this framework due to the hidden variables, however we can exploit the properties of certain dynamical systems to formulate exact methods based on state space reconstruction. We approach the problem by using reconstruction theorems to analytically derive a tractable expression for the KL-divergence of a candidate DAG from the observed dataset. We show this measure can be decomposed as a function of two information-theoretic measures, transfer entropy and stochastic interaction. We then present two mathematically robust scoring functions based on transfer entropy and statistical independence tests. These results support the previously held conjecture that transfer entropy can be used to infer effective connectivity in complex networks.
[ { "version": "v1", "created": "Wed, 2 Nov 2016 11:23:54 GMT" } ]
2016-11-03T00:00:00
[ [ "Cliff", "Oliver M.", "" ], [ "Prokopenko", "Mikhail", "" ], [ "Fitch", "Robert", "" ] ]
TITLE: Inferring Coupling of Distributed Dynamical Systems via Transfer Entropy ABSTRACT: In this work, we are interested in structure learning for a set of spatially distributed dynamical systems, where individual subsystems are coupled via latent variables and observed through a filter. We represent this model as a directed acyclic graph (DAG) that characterises the unidirectional coupling between subsystems. Standard approaches to structure learning are not applicable in this framework due to the hidden variables, however we can exploit the properties of certain dynamical systems to formulate exact methods based on state space reconstruction. We approach the problem by using reconstruction theorems to analytically derive a tractable expression for the KL-divergence of a candidate DAG from the observed dataset. We show this measure can be decomposed as a function of two information-theoretic measures, transfer entropy and stochastic interaction. We then present two mathematically robust scoring functions based on transfer entropy and statistical independence tests. These results support the previously held conjecture that transfer entropy can be used to infer effective connectivity in complex networks.
no_new_dataset
0.943348
1611.00714
Alexander Jung
Alexander Jung and Alfred O. Hero III and Alexandru Mara and Sabeur Aridhi
Scalable Semi-Supervised Learning over Networks using Nonsmooth Convex Optimization
null
null
null
null
cs.LG cs.DC
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a scalable method for semi-supervised (transductive) learning from massive network-structured datasets. Our approach to semi-supervised learning is based on representing the underlying hypothesis as a graph signal with small total variation. Requiring a small total variation of the graph signal representing the underlying hypothesis corresponds to the central smoothness assumption that forms the basis for semi-supervised learning, i.e., input points forming clusters have similar output values or labels. We formulate the learning problem as a nonsmooth convex optimization problem which we solve by appealing to Nesterovs optimal first-order method for nonsmooth optimization. We also provide a message passing formulation of the learning method which allows for a highly scalable implementation in big data frameworks.
[ { "version": "v1", "created": "Wed, 2 Nov 2016 18:27:53 GMT" } ]
2016-11-03T00:00:00
[ [ "Jung", "Alexander", "" ], [ "Hero", "Alfred O.", "III" ], [ "Mara", "Alexandru", "" ], [ "Aridhi", "Sabeur", "" ] ]
TITLE: Scalable Semi-Supervised Learning over Networks using Nonsmooth Convex Optimization ABSTRACT: We propose a scalable method for semi-supervised (transductive) learning from massive network-structured datasets. Our approach to semi-supervised learning is based on representing the underlying hypothesis as a graph signal with small total variation. Requiring a small total variation of the graph signal representing the underlying hypothesis corresponds to the central smoothness assumption that forms the basis for semi-supervised learning, i.e., input points forming clusters have similar output values or labels. We formulate the learning problem as a nonsmooth convex optimization problem which we solve by appealing to Nesterovs optimal first-order method for nonsmooth optimization. We also provide a message passing formulation of the learning method which allows for a highly scalable implementation in big data frameworks.
no_new_dataset
0.950457
1511.06049
Deyu Meng
Deyu Meng and Qian Zhao and Lu Jiang
What Objective Does Self-paced Learning Indeed Optimize?
25 pages, 1 figures
null
null
null
cs.LG cs.CV
http://creativecommons.org/publicdomain/zero/1.0/
Self-paced learning (SPL) is a recently raised methodology designed through simulating the learning principle of humans/animals. A variety of SPL realization schemes have been designed for different computer vision and pattern recognition tasks, and empirically substantiated to be effective in these applications. However, the investigation on its theoretical insight is still a blank. To this issue, this study attempts to provide some new theoretical understanding under the SPL scheme. Specifically, we prove that the solving strategy on SPL accords with a majorization minimization algorithm implemented on a latent objective function. Furthermore, we find that the loss function contained in this latent objective has a similar configuration with non-convex regularized penalty (NSPR) known in statistics and machine learning. Such connection inspires us discovering more intrinsic relationship between SPL regimes and NSPR forms, like SCAD, LOG and EXP. The robustness insight under SPL can then be finely explained. We also analyze the capability of SPL on its easy loss prior embedding property, and provide an insightful interpretation to the effectiveness mechanism under previous SPL variations. Besides, we design a group-partial-order loss prior, which is especially useful to weakly labeled large-scale data processing tasks. Through applying SPL with this loss prior to the FCVID dataset, which is currently one of the biggest manually annotated video dataset, our method achieves state-of-the-art performance beyond previous methods, which further helps supports the proposed theoretical arguments.
[ { "version": "v1", "created": "Thu, 19 Nov 2015 02:55:18 GMT" }, { "version": "v2", "created": "Tue, 1 Nov 2016 13:59:27 GMT" } ]
2016-11-02T00:00:00
[ [ "Meng", "Deyu", "" ], [ "Zhao", "Qian", "" ], [ "Jiang", "Lu", "" ] ]
TITLE: What Objective Does Self-paced Learning Indeed Optimize? ABSTRACT: Self-paced learning (SPL) is a recently raised methodology designed through simulating the learning principle of humans/animals. A variety of SPL realization schemes have been designed for different computer vision and pattern recognition tasks, and empirically substantiated to be effective in these applications. However, the investigation on its theoretical insight is still a blank. To this issue, this study attempts to provide some new theoretical understanding under the SPL scheme. Specifically, we prove that the solving strategy on SPL accords with a majorization minimization algorithm implemented on a latent objective function. Furthermore, we find that the loss function contained in this latent objective has a similar configuration with non-convex regularized penalty (NSPR) known in statistics and machine learning. Such connection inspires us discovering more intrinsic relationship between SPL regimes and NSPR forms, like SCAD, LOG and EXP. The robustness insight under SPL can then be finely explained. We also analyze the capability of SPL on its easy loss prior embedding property, and provide an insightful interpretation to the effectiveness mechanism under previous SPL variations. Besides, we design a group-partial-order loss prior, which is especially useful to weakly labeled large-scale data processing tasks. Through applying SPL with this loss prior to the FCVID dataset, which is currently one of the biggest manually annotated video dataset, our method achieves state-of-the-art performance beyond previous methods, which further helps supports the proposed theoretical arguments.
no_new_dataset
0.942401
1609.03426
Sayantan Dasgupta
Sayantan Dasgupta
Multi-Label Learning with Provable Guarantee
null
null
null
null
cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Here we study the problem of learning labels for large text corpora where each text can be assigned a variable number of labels. The problem might seem trivial when the label dimensionality is small and can be easily solved using a series of one-vs-all classifiers. However, as the label dimensionality increases to several thousand, the parameter space becomes extremely large, and it is no longer possible to use the one-vs-all technique. Here we propose a model based on the factorization of higher order moments of the words in the corpora, as well as the cross moment between the labels and the words for multi-label prediction. Our model provides guaranteed convergence bounds on the estimated parameters. Further, our model takes only three passes through the training dataset to extract the parameters, resulting in a highly scalable algorithm that can train on GB's of data consisting of millions of documents with hundreds of thousands of labels using a nominal resource of a single processor with 16GB RAM. Our model achieves 10x-15x order of speed-up on large-scale datasets while producing competitive performance in comparison with existing benchmark algorithms.
[ { "version": "v1", "created": "Mon, 12 Sep 2016 14:38:08 GMT" }, { "version": "v2", "created": "Tue, 13 Sep 2016 23:26:50 GMT" }, { "version": "v3", "created": "Sun, 18 Sep 2016 14:57:20 GMT" }, { "version": "v4", "created": "Tue, 1 Nov 2016 16:21:54 GMT" } ]
2016-11-02T00:00:00
[ [ "Dasgupta", "Sayantan", "" ] ]
TITLE: Multi-Label Learning with Provable Guarantee ABSTRACT: Here we study the problem of learning labels for large text corpora where each text can be assigned a variable number of labels. The problem might seem trivial when the label dimensionality is small and can be easily solved using a series of one-vs-all classifiers. However, as the label dimensionality increases to several thousand, the parameter space becomes extremely large, and it is no longer possible to use the one-vs-all technique. Here we propose a model based on the factorization of higher order moments of the words in the corpora, as well as the cross moment between the labels and the words for multi-label prediction. Our model provides guaranteed convergence bounds on the estimated parameters. Further, our model takes only three passes through the training dataset to extract the parameters, resulting in a highly scalable algorithm that can train on GB's of data consisting of millions of documents with hundreds of thousands of labels using a nominal resource of a single processor with 16GB RAM. Our model achieves 10x-15x order of speed-up on large-scale datasets while producing competitive performance in comparison with existing benchmark algorithms.
no_new_dataset
0.944689
1609.04855
Kenji Hata
Kenji Hata, Ranjay Krishna, Li Fei-Fei, Michael S. Bernstein
A Glimpse Far into the Future: Understanding Long-term Crowd Worker Quality
10 pages, 11 figures, accepted CSCW 2017
null
10.1145/2998181.2998248
null
cs.HC cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Microtask crowdsourcing is increasingly critical to the creation of extremely large datasets. As a result, crowd workers spend weeks or months repeating the exact same tasks, making it necessary to understand their behavior over these long periods of time. We utilize three large, longitudinal datasets of nine million annotations collected from Amazon Mechanical Turk to examine claims that workers fatigue or satisfice over these long periods, producing lower quality work. We find that, contrary to these claims, workers are extremely stable in their quality over the entire period. To understand whether workers set their quality based on the task's requirements for acceptance, we then perform an experiment where we vary the required quality for a large crowdsourcing task. Workers did not adjust their quality based on the acceptance threshold: workers who were above the threshold continued working at their usual quality level, and workers below the threshold self-selected themselves out of the task. Capitalizing on this consistency, we demonstrate that it is possible to predict workers' long-term quality using just a glimpse of their quality on the first five tasks.
[ { "version": "v1", "created": "Thu, 15 Sep 2016 20:47:51 GMT" }, { "version": "v2", "created": "Tue, 1 Nov 2016 17:34:10 GMT" } ]
2016-11-02T00:00:00
[ [ "Hata", "Kenji", "" ], [ "Krishna", "Ranjay", "" ], [ "Fei-Fei", "Li", "" ], [ "Bernstein", "Michael S.", "" ] ]
TITLE: A Glimpse Far into the Future: Understanding Long-term Crowd Worker Quality ABSTRACT: Microtask crowdsourcing is increasingly critical to the creation of extremely large datasets. As a result, crowd workers spend weeks or months repeating the exact same tasks, making it necessary to understand their behavior over these long periods of time. We utilize three large, longitudinal datasets of nine million annotations collected from Amazon Mechanical Turk to examine claims that workers fatigue or satisfice over these long periods, producing lower quality work. We find that, contrary to these claims, workers are extremely stable in their quality over the entire period. To understand whether workers set their quality based on the task's requirements for acceptance, we then perform an experiment where we vary the required quality for a large crowdsourcing task. Workers did not adjust their quality based on the acceptance threshold: workers who were above the threshold continued working at their usual quality level, and workers below the threshold self-selected themselves out of the task. Capitalizing on this consistency, we demonstrate that it is possible to predict workers' long-term quality using just a glimpse of their quality on the first five tasks.
no_new_dataset
0.924005
1611.00129
Jiecao Chen
Jiecao Chen, Huy L. Nguyen, Qin Zhang
Submodular Maximization over Sliding Windows
13 pages
null
null
null
cs.DS
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we study the extraction of representative elements in the data stream model in the form of submodular maximization. Different from the previous work on streaming submodular maximization, we are interested only in the recent data, and study the maximization problem over sliding windows. We provide a general reduction from the sliding window model to the standard streaming model, and thus our approach works for general constraints as long as there is a corresponding streaming algorithm in the standard streaming model. As a consequence, we obtain the first algorithms in the sliding window model for maximizing a monotone/non-monotone submodular function under cardinality and matroid constraints. We also propose several heuristics and show their efficiency in real-world datasets.
[ { "version": "v1", "created": "Tue, 1 Nov 2016 05:06:37 GMT" } ]
2016-11-02T00:00:00
[ [ "Chen", "Jiecao", "" ], [ "Nguyen", "Huy L.", "" ], [ "Zhang", "Qin", "" ] ]
TITLE: Submodular Maximization over Sliding Windows ABSTRACT: In this paper we study the extraction of representative elements in the data stream model in the form of submodular maximization. Different from the previous work on streaming submodular maximization, we are interested only in the recent data, and study the maximization problem over sliding windows. We provide a general reduction from the sliding window model to the standard streaming model, and thus our approach works for general constraints as long as there is a corresponding streaming algorithm in the standard streaming model. As a consequence, we obtain the first algorithms in the sliding window model for maximizing a monotone/non-monotone submodular function under cardinality and matroid constraints. We also propose several heuristics and show their efficiency in real-world datasets.
no_new_dataset
0.951684
1611.00144
Yanru Qu
Yanru Qu, Han Cai, Kan Ren, Weinan Zhang, Yong Yu, Ying Wen, Jun Wang
Product-based Neural Networks for User Response Prediction
6 pages, 5 figures, ICDM2016
null
null
null
cs.LG cs.IR
http://creativecommons.org/licenses/by/4.0/
Predicting user responses, such as clicks and conversions, is of great importance and has found its usage in many Web applications including recommender systems, web search and online advertising. The data in those applications is mostly categorical and contains multiple fields; a typical representation is to transform it into a high-dimensional sparse binary feature representation via one-hot encoding. Facing with the extreme sparsity, traditional models may limit their capacity of mining shallow patterns from the data, i.e. low-order feature combinations. Deep models like deep neural networks, on the other hand, cannot be directly applied for the high-dimensional input because of the huge feature space. In this paper, we propose a Product-based Neural Networks (PNN) with an embedding layer to learn a distributed representation of the categorical data, a product layer to capture interactive patterns between inter-field categories, and further fully connected layers to explore high-order feature interactions. Our experimental results on two large-scale real-world ad click datasets demonstrate that PNNs consistently outperform the state-of-the-art models on various metrics.
[ { "version": "v1", "created": "Tue, 1 Nov 2016 07:10:22 GMT" } ]
2016-11-02T00:00:00
[ [ "Qu", "Yanru", "" ], [ "Cai", "Han", "" ], [ "Ren", "Kan", "" ], [ "Zhang", "Weinan", "" ], [ "Yu", "Yong", "" ], [ "Wen", "Ying", "" ], [ "Wang", "Jun", "" ] ]
TITLE: Product-based Neural Networks for User Response Prediction ABSTRACT: Predicting user responses, such as clicks and conversions, is of great importance and has found its usage in many Web applications including recommender systems, web search and online advertising. The data in those applications is mostly categorical and contains multiple fields; a typical representation is to transform it into a high-dimensional sparse binary feature representation via one-hot encoding. Facing with the extreme sparsity, traditional models may limit their capacity of mining shallow patterns from the data, i.e. low-order feature combinations. Deep models like deep neural networks, on the other hand, cannot be directly applied for the high-dimensional input because of the huge feature space. In this paper, we propose a Product-based Neural Networks (PNN) with an embedding layer to learn a distributed representation of the categorical data, a product layer to capture interactive patterns between inter-field categories, and further fully connected layers to explore high-order feature interactions. Our experimental results on two large-scale real-world ad click datasets demonstrate that PNNs consistently outperform the state-of-the-art models on various metrics.
no_new_dataset
0.948202
1611.00218
Yashas Annadani
Yashas Annadani, D L Rakshith, Soma Biswas
Sliding Dictionary Based Sparse Representation For Action Recognition
7 Pages
null
null
null
cs.CV
http://creativecommons.org/licenses/by-nc-sa/4.0/
The task of action recognition has been in the forefront of research, given its applications in gaming, surveillance and health care. In this work, we propose a simple, yet very effective approach which works seamlessly for both offline and online action recognition using the skeletal joints. We construct a sliding dictionary which has the training data along with their time stamps. This is used to compute the sparse coefficients of the input action sequence which is divided into overlapping windows and each window gives a probability score for each action class. In addition, we compute another simple feature, which calibrates each of the action sequences to the training sequences, and models the deviation of the action from the each of the training data. Finally, a score level fusion of the two heterogeneous but complementary features for each window is obtained and the scores for the available windows are successively combined to give the confidence scores of each action class. This way of combining the scores makes the approach suitable for scenarios where only part of the sequence is available. Extensive experimental evaluation on three publicly available datasets shows the effectiveness of the proposed approach for both offline and online action recognition tasks.
[ { "version": "v1", "created": "Tue, 1 Nov 2016 13:29:38 GMT" } ]
2016-11-02T00:00:00
[ [ "Annadani", "Yashas", "" ], [ "Rakshith", "D L", "" ], [ "Biswas", "Soma", "" ] ]
TITLE: Sliding Dictionary Based Sparse Representation For Action Recognition ABSTRACT: The task of action recognition has been in the forefront of research, given its applications in gaming, surveillance and health care. In this work, we propose a simple, yet very effective approach which works seamlessly for both offline and online action recognition using the skeletal joints. We construct a sliding dictionary which has the training data along with their time stamps. This is used to compute the sparse coefficients of the input action sequence which is divided into overlapping windows and each window gives a probability score for each action class. In addition, we compute another simple feature, which calibrates each of the action sequences to the training sequences, and models the deviation of the action from the each of the training data. Finally, a score level fusion of the two heterogeneous but complementary features for each window is obtained and the scores for the available windows are successively combined to give the confidence scores of each action class. This way of combining the scores makes the approach suitable for scenarios where only part of the sequence is available. Extensive experimental evaluation on three publicly available datasets shows the effectiveness of the proposed approach for both offline and online action recognition tasks.
no_new_dataset
0.943504
1611.00291
Vikram Krishnamurthy
Vikram Krishnamurthy and Anup Aprem and Sujay Bhatt
Opportunistic Advertisement Scheduling in Live Social Media: A Multiple Stopping Time POMDP Approach
null
null
null
null
cs.SI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Live online social broadcasting services like YouTube Live and Twitch have steadily gained popularity due to improved bandwidth, ease of generating content and the ability to earn revenue on the generated content. In contrast to traditional cable television, revenue in online services is generated solely through advertisements, and depends on the number of clicks generated. Channel owners aim to opportunistically schedule advertisements so as to generate maximum revenue. This paper considers the problem of optimal scheduling of advertisements in live online social media. The problem is formulated as a multiple stopping problem and is addressed in a partially observed Markov decision process (POMDP) framework. Structural results are provided on the optimal advertisement scheduling policy. By exploiting the structure of the optimal policy, best linear thresholds are computed using stochastic approximation. The proposed model and framework are validated on real datasets, and the following observations are made: (i) The policy obtained by the multiple stopping problem can be used to detect changes in ground truth from online search data (ii) Numerical results show a significant improvement in the expected revenue by opportunistically scheduling the advertisements. The revenue can be improved by $20-30\%$ in comparison to currently employed periodic scheduling.
[ { "version": "v1", "created": "Tue, 1 Nov 2016 16:48:10 GMT" } ]
2016-11-02T00:00:00
[ [ "Krishnamurthy", "Vikram", "" ], [ "Aprem", "Anup", "" ], [ "Bhatt", "Sujay", "" ] ]
TITLE: Opportunistic Advertisement Scheduling in Live Social Media: A Multiple Stopping Time POMDP Approach ABSTRACT: Live online social broadcasting services like YouTube Live and Twitch have steadily gained popularity due to improved bandwidth, ease of generating content and the ability to earn revenue on the generated content. In contrast to traditional cable television, revenue in online services is generated solely through advertisements, and depends on the number of clicks generated. Channel owners aim to opportunistically schedule advertisements so as to generate maximum revenue. This paper considers the problem of optimal scheduling of advertisements in live online social media. The problem is formulated as a multiple stopping problem and is addressed in a partially observed Markov decision process (POMDP) framework. Structural results are provided on the optimal advertisement scheduling policy. By exploiting the structure of the optimal policy, best linear thresholds are computed using stochastic approximation. The proposed model and framework are validated on real datasets, and the following observations are made: (i) The policy obtained by the multiple stopping problem can be used to detect changes in ground truth from online search data (ii) Numerical results show a significant improvement in the expected revenue by opportunistically scheduling the advertisements. The revenue can be improved by $20-30\%$ in comparison to currently employed periodic scheduling.
no_new_dataset
0.950273
1412.3708
Marc Goessling
Marc Goessling and Yali Amit
Compact Compositional Models
null
null
null
null
cs.CV cs.LG stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Learning compact and interpretable representations is a very natural task, which has not been solved satisfactorily even for simple binary datasets. In this paper, we review various ways of composing experts for binary data and argue that competitive forms of interaction are best suited to learn low-dimensional representations. We propose a new composition rule that discourages experts from focusing on similar structures and that penalizes opposing votes strongly so that abstaining from voting becomes more attractive. We also introduce a novel sequential initialization procedure, which is based on a process of oversimplification and correction. Experiments show that with our approach very intuitive models can be learned.
[ { "version": "v1", "created": "Thu, 11 Dec 2014 16:19:56 GMT" }, { "version": "v2", "created": "Wed, 25 Feb 2015 19:23:27 GMT" }, { "version": "v3", "created": "Wed, 8 Apr 2015 22:02:42 GMT" }, { "version": "v4", "created": "Sat, 29 Oct 2016 22:49:39 GMT" } ]
2016-11-01T00:00:00
[ [ "Goessling", "Marc", "" ], [ "Amit", "Yali", "" ] ]
TITLE: Compact Compositional Models ABSTRACT: Learning compact and interpretable representations is a very natural task, which has not been solved satisfactorily even for simple binary datasets. In this paper, we review various ways of composing experts for binary data and argue that competitive forms of interaction are best suited to learn low-dimensional representations. We propose a new composition rule that discourages experts from focusing on similar structures and that penalizes opposing votes strongly so that abstaining from voting becomes more attractive. We also introduce a novel sequential initialization procedure, which is based on a process of oversimplification and correction. Experiments show that with our approach very intuitive models can be learned.
no_new_dataset
0.948202
1510.09083
Hanjiang Lai
Hanjiang Lai, Shengtao Xiao, Yan Pan, Zhen Cui, Jiashi Feng, Chunyan Xu, Jian Yin and Shuicheng Yan
Deep Recurrent Regression for Facial Landmark Detection
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a novel end-to-end deep architecture for face landmark detection, based on a deep convolutional and deconvolutional network followed by carefully designed recurrent network structures. The pipeline of this architecture consists of three parts. Through the first part, we encode an input face image to resolution-preserved deconvolutional feature maps via a deep network with stacked convolutional and deconvolutional layers. Then, in the second part, we estimate the initial coordinates of the facial key points by an additional convolutional layer on top of these deconvolutional feature maps. In the last part, by using the deconvolutional feature maps and the initial facial key points as input, we refine the coordinates of the facial key points by a recurrent network that consists of multiple Long-Short Term Memory (LSTM) components. Extensive evaluations on several benchmark datasets show that the proposed deep architecture has superior performance against the state-of-the-art methods.
[ { "version": "v1", "created": "Fri, 30 Oct 2015 13:34:18 GMT" }, { "version": "v2", "created": "Fri, 13 Nov 2015 01:54:11 GMT" }, { "version": "v3", "created": "Mon, 31 Oct 2016 03:29:54 GMT" } ]
2016-11-01T00:00:00
[ [ "Lai", "Hanjiang", "" ], [ "Xiao", "Shengtao", "" ], [ "Pan", "Yan", "" ], [ "Cui", "Zhen", "" ], [ "Feng", "Jiashi", "" ], [ "Xu", "Chunyan", "" ], [ "Yin", "Jian", "" ], [ "Yan", "Shuicheng", "" ] ]
TITLE: Deep Recurrent Regression for Facial Landmark Detection ABSTRACT: We propose a novel end-to-end deep architecture for face landmark detection, based on a deep convolutional and deconvolutional network followed by carefully designed recurrent network structures. The pipeline of this architecture consists of three parts. Through the first part, we encode an input face image to resolution-preserved deconvolutional feature maps via a deep network with stacked convolutional and deconvolutional layers. Then, in the second part, we estimate the initial coordinates of the facial key points by an additional convolutional layer on top of these deconvolutional feature maps. In the last part, by using the deconvolutional feature maps and the initial facial key points as input, we refine the coordinates of the facial key points by a recurrent network that consists of multiple Long-Short Term Memory (LSTM) components. Extensive evaluations on several benchmark datasets show that the proposed deep architecture has superior performance against the state-of-the-art methods.
no_new_dataset
0.943867
1511.05933
Sayantan Dasgupta
Sayantan Dasgupta
Seeding K-Means using Method of Moments
Paper contained an error in Equation 5 and 7
null
null
null
cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
K-means is one of the most widely used algorithms for clustering in Data Mining applications, which attempts to minimize the sum of the square of the Euclidean distance of the points in the clusters from the respective means of the clusters. However, K-means suffers from local minima problem and is not guaranteed to converge to the optimal cost. K-means++ tries to address the problem by seeding the means using a distance-based sampling scheme. However, seeding the means in K-means++ needs $O\left(K\right)$ sequential passes through the entire dataset, and this can be very costly for large datasets. Here we propose a method of seeding the initial means based on factorizations of higher order moments for bounded data. Our method takes $O\left(1\right)$ passes through the entire dataset to extract the initial set of means, and its final cost can be proven to be within $O(\sqrt{K})$ of the optimal cost. We demonstrate the performance of our algorithm in comparison with the existing algorithms on various benchmark datasets.
[ { "version": "v1", "created": "Wed, 18 Nov 2015 20:26:42 GMT" }, { "version": "v2", "created": "Sat, 21 Nov 2015 21:54:01 GMT" }, { "version": "v3", "created": "Thu, 4 Feb 2016 10:21:55 GMT" }, { "version": "v4", "created": "Thu, 3 Mar 2016 17:40:02 GMT" }, { "version": "v5", "created": "Thu, 21 Apr 2016 21:50:39 GMT" }, { "version": "v6", "created": "Fri, 3 Jun 2016 17:50:10 GMT" }, { "version": "v7", "created": "Mon, 12 Sep 2016 22:33:06 GMT" }, { "version": "v8", "created": "Mon, 31 Oct 2016 15:59:13 GMT" } ]
2016-11-01T00:00:00
[ [ "Dasgupta", "Sayantan", "" ] ]
TITLE: Seeding K-Means using Method of Moments ABSTRACT: K-means is one of the most widely used algorithms for clustering in Data Mining applications, which attempts to minimize the sum of the square of the Euclidean distance of the points in the clusters from the respective means of the clusters. However, K-means suffers from local minima problem and is not guaranteed to converge to the optimal cost. K-means++ tries to address the problem by seeding the means using a distance-based sampling scheme. However, seeding the means in K-means++ needs $O\left(K\right)$ sequential passes through the entire dataset, and this can be very costly for large datasets. Here we propose a method of seeding the initial means based on factorizations of higher order moments for bounded data. Our method takes $O\left(1\right)$ passes through the entire dataset to extract the initial set of means, and its final cost can be proven to be within $O(\sqrt{K})$ of the optimal cost. We demonstrate the performance of our algorithm in comparison with the existing algorithms on various benchmark datasets.
no_new_dataset
0.946941
1512.02363
Christian Forster
Christian Forster, Luca Carlone, Frank Dellaert, Davide Scaramuzza
On-Manifold Preintegration for Real-Time Visual-Inertial Odometry
20 pages, 24 figures, accepted for publication in IEEE Transactions on Robotics (TRO) 2016
null
10.1109/TRO.2016.2597321
null
cs.RO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Current approaches for visual-inertial odometry (VIO) are able to attain highly accurate state estimation via nonlinear optimization. However, real-time optimization quickly becomes infeasible as the trajectory grows over time, this problem is further emphasized by the fact that inertial measurements come at high rate, hence leading to fast growth of the number of variables in the optimization. In this paper, we address this issue by preintegrating inertial measurements between selected keyframes into single relative motion constraints. Our first contribution is a \emph{preintegration theory} that properly addresses the manifold structure of the rotation group. We formally discuss the generative measurement model as well as the nature of the rotation noise and derive the expression for the \emph{maximum a posteriori} state estimator. Our theoretical development enables the computation of all necessary Jacobians for the optimization and a-posteriori bias correction in analytic form. The second contribution is to show that the preintegrated IMU model can be seamlessly integrated into a visual-inertial pipeline under the unifying framework of factor graphs. This enables the application of incremental-smoothing algorithms and the use of a \emph{structureless} model for visual measurements, which avoids optimizing over the 3D points, further accelerating the computation. We perform an extensive evaluation of our monocular \VIO pipeline on real and simulated datasets. The results confirm that our modelling effort leads to accurate state estimation in real-time, outperforming state-of-the-art approaches.
[ { "version": "v1", "created": "Tue, 8 Dec 2015 08:26:25 GMT" }, { "version": "v2", "created": "Tue, 19 Jul 2016 07:24:26 GMT" }, { "version": "v3", "created": "Sun, 30 Oct 2016 10:43:58 GMT" } ]
2016-11-01T00:00:00
[ [ "Forster", "Christian", "" ], [ "Carlone", "Luca", "" ], [ "Dellaert", "Frank", "" ], [ "Scaramuzza", "Davide", "" ] ]
TITLE: On-Manifold Preintegration for Real-Time Visual-Inertial Odometry ABSTRACT: Current approaches for visual-inertial odometry (VIO) are able to attain highly accurate state estimation via nonlinear optimization. However, real-time optimization quickly becomes infeasible as the trajectory grows over time, this problem is further emphasized by the fact that inertial measurements come at high rate, hence leading to fast growth of the number of variables in the optimization. In this paper, we address this issue by preintegrating inertial measurements between selected keyframes into single relative motion constraints. Our first contribution is a \emph{preintegration theory} that properly addresses the manifold structure of the rotation group. We formally discuss the generative measurement model as well as the nature of the rotation noise and derive the expression for the \emph{maximum a posteriori} state estimator. Our theoretical development enables the computation of all necessary Jacobians for the optimization and a-posteriori bias correction in analytic form. The second contribution is to show that the preintegrated IMU model can be seamlessly integrated into a visual-inertial pipeline under the unifying framework of factor graphs. This enables the application of incremental-smoothing algorithms and the use of a \emph{structureless} model for visual measurements, which avoids optimizing over the 3D points, further accelerating the computation. We perform an extensive evaluation of our monocular \VIO pipeline on real and simulated datasets. The results confirm that our modelling effort leads to accurate state estimation in real-time, outperforming state-of-the-art approaches.
no_new_dataset
0.947721
1604.08672
Shufeng Xiong
Shufeng Xiong, Yue Zhang, Donghong Ji, Yinxia Lou
Distance Metric Learning for Aspect Phrase Grouping
null
null
null
null
cs.CL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Aspect phrase grouping is an important task in aspect-level sentiment analysis. It is a challenging problem due to polysemy and context dependency. We propose an Attention-based Deep Distance Metric Learning (ADDML) method, by considering aspect phrase representation as well as context representation. First, leveraging the characteristics of the review text, we automatically generate aspect phrase sample pairs for distant supervision. Second, we feed word embeddings of aspect phrases and their contexts into an attention-based neural network to learn feature representation of contexts. Both aspect phrase embedding and context embedding are used to learn a deep feature subspace for measure the distances between aspect phrases for K-means clustering. Experiments on four review datasets show that the proposed method outperforms state-of-the-art strong baseline methods.
[ { "version": "v1", "created": "Fri, 29 Apr 2016 02:44:02 GMT" }, { "version": "v2", "created": "Sun, 30 Oct 2016 02:09:15 GMT" } ]
2016-11-01T00:00:00
[ [ "Xiong", "Shufeng", "" ], [ "Zhang", "Yue", "" ], [ "Ji", "Donghong", "" ], [ "Lou", "Yinxia", "" ] ]
TITLE: Distance Metric Learning for Aspect Phrase Grouping ABSTRACT: Aspect phrase grouping is an important task in aspect-level sentiment analysis. It is a challenging problem due to polysemy and context dependency. We propose an Attention-based Deep Distance Metric Learning (ADDML) method, by considering aspect phrase representation as well as context representation. First, leveraging the characteristics of the review text, we automatically generate aspect phrase sample pairs for distant supervision. Second, we feed word embeddings of aspect phrases and their contexts into an attention-based neural network to learn feature representation of contexts. Both aspect phrase embedding and context embedding are used to learn a deep feature subspace for measure the distances between aspect phrases for K-means clustering. Experiments on four review datasets show that the proposed method outperforms state-of-the-art strong baseline methods.
no_new_dataset
0.949012
1606.00487
Sepehr Valipour
Sepehr Valipour, Mennatullah Siam, Martin Jagersand, Nilanjan Ray
Recurrent Fully Convolutional Networks for Video Segmentation
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Image segmentation is an important step in most visual tasks. While convolutional neural networks have shown to perform well on single image segmentation, to our knowledge, no study has been been done on leveraging recurrent gated architectures for video segmentation. Accordingly, we propose a novel method for online segmentation of video sequences that incorporates temporal data. The network is built from fully convolutional element and recurrent unit that works on a sliding window over the temporal data. We also introduce a novel convolutional gated recurrent unit that preserves the spatial information and reduces the parameters learned. Our method has the advantage that it can work in an online fashion instead of operating over the whole input batch of video frames. The network is tested on the change detection dataset, and proved to have 5.5\% improvement in F-measure over a plain fully convolutional network for per frame segmentation. It was also shown to have improvement of 1.4\% for the F-measure compared to our baseline network that we call FCN 12s.
[ { "version": "v1", "created": "Wed, 1 Jun 2016 22:27:41 GMT" }, { "version": "v2", "created": "Thu, 9 Jun 2016 07:24:00 GMT" }, { "version": "v3", "created": "Mon, 31 Oct 2016 00:05:49 GMT" } ]
2016-11-01T00:00:00
[ [ "Valipour", "Sepehr", "" ], [ "Siam", "Mennatullah", "" ], [ "Jagersand", "Martin", "" ], [ "Ray", "Nilanjan", "" ] ]
TITLE: Recurrent Fully Convolutional Networks for Video Segmentation ABSTRACT: Image segmentation is an important step in most visual tasks. While convolutional neural networks have shown to perform well on single image segmentation, to our knowledge, no study has been been done on leveraging recurrent gated architectures for video segmentation. Accordingly, we propose a novel method for online segmentation of video sequences that incorporates temporal data. The network is built from fully convolutional element and recurrent unit that works on a sliding window over the temporal data. We also introduce a novel convolutional gated recurrent unit that preserves the spatial information and reduces the parameters learned. Our method has the advantage that it can work in an online fashion instead of operating over the whole input batch of video frames. The network is tested on the change detection dataset, and proved to have 5.5\% improvement in F-measure over a plain fully convolutional network for per frame segmentation. It was also shown to have improvement of 1.4\% for the F-measure compared to our baseline network that we call FCN 12s.
no_new_dataset
0.950134
1606.03558
Christopher Bongsoo Choy
Christopher B. Choy, JunYoung Gwak, Silvio Savarese, Manmohan Chandraker
Universal Correspondence Network
To appear at NIPS 2016 as full oral presentation
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a deep learning framework for accurate visual correspondences and demonstrate its effectiveness for both geometric and semantic matching, spanning across rigid motions to intra-class shape or appearance variations. In contrast to previous CNN-based approaches that optimize a surrogate patch similarity objective, we use deep metric learning to directly learn a feature space that preserves either geometric or semantic similarity. Our fully convolutional architecture, along with a novel correspondence contrastive loss allows faster training by effective reuse of computations, accurate gradient computation through the use of thousands of examples per image pair and faster testing with $O(n)$ feed forward passes for $n$ keypoints, instead of $O(n^2)$ for typical patch similarity methods. We propose a convolutional spatial transformer to mimic patch normalization in traditional features like SIFT, which is shown to dramatically boost accuracy for semantic correspondences across intra-class shape variations. Extensive experiments on KITTI, PASCAL, and CUB-2011 datasets demonstrate the significant advantages of our features over prior works that use either hand-constructed or learned features.
[ { "version": "v1", "created": "Sat, 11 Jun 2016 06:27:09 GMT" }, { "version": "v2", "created": "Tue, 14 Jun 2016 23:16:13 GMT" }, { "version": "v3", "created": "Mon, 31 Oct 2016 06:32:03 GMT" } ]
2016-11-01T00:00:00
[ [ "Choy", "Christopher B.", "" ], [ "Gwak", "JunYoung", "" ], [ "Savarese", "Silvio", "" ], [ "Chandraker", "Manmohan", "" ] ]
TITLE: Universal Correspondence Network ABSTRACT: We present a deep learning framework for accurate visual correspondences and demonstrate its effectiveness for both geometric and semantic matching, spanning across rigid motions to intra-class shape or appearance variations. In contrast to previous CNN-based approaches that optimize a surrogate patch similarity objective, we use deep metric learning to directly learn a feature space that preserves either geometric or semantic similarity. Our fully convolutional architecture, along with a novel correspondence contrastive loss allows faster training by effective reuse of computations, accurate gradient computation through the use of thousands of examples per image pair and faster testing with $O(n)$ feed forward passes for $n$ keypoints, instead of $O(n^2)$ for typical patch similarity methods. We propose a convolutional spatial transformer to mimic patch normalization in traditional features like SIFT, which is shown to dramatically boost accuracy for semantic correspondences across intra-class shape variations. Extensive experiments on KITTI, PASCAL, and CUB-2011 datasets demonstrate the significant advantages of our features over prior works that use either hand-constructed or learned features.
no_new_dataset
0.946794
1607.02937
Gabriel Gon\c{c}alves
Gabriel Resende Gon\c{c}alves, Sirlene Pio Gomes da Silva, David Menotti, William Robson Schwartz
Benchmark for License Plate Character Segmentation
32 pages, single column
J. Electron. Imaging. 25(5), 053034 (Oct 24, 2016)
10.1117/1.JEI.25.5.053034
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Automatic License Plate Recognition (ALPR) has been the focus of many researches in the past years. In general, ALPR is divided into the following problems: detection of on-track vehicles, license plates detection, segmention of license plate characters and optical character recognition (OCR). Even though commercial solutions are available for controlled acquisition conditions, e.g., the entrance of a parking lot, ALPR is still an open problem when dealing with data acquired from uncontrolled environments, such as roads and highways when relying only on imaging sensors. Due to the multiple orientations and scales of the license plates captured by the camera, a very challenging task of the ALPR is the License Plate Character Segmentation (LPCS) step, which effectiveness is required to be (near) optimal to achieve a high recognition rate by the OCR. To tackle the LPCS problem, this work proposes a novel benchmark composed of a dataset designed to focus specifically on the character segmentation step of the ALPR within an evaluation protocol. Furthermore, we propose the Jaccard-Centroid coefficient, a new evaluation measure more suitable than the Jaccard coefficient regarding the location of the bounding box within the ground-truth annotation. The dataset is composed of 2,000 Brazilian license plates consisting of 14,000 alphanumeric symbols and their corresponding bounding box annotations. We also present a new straightforward approach to perform LPCS efficiently. Finally, we provide an experimental evaluation for the dataset based on four LPCS approaches and demonstrate the importance of character segmentation for achieving an accurate OCR.
[ { "version": "v1", "created": "Mon, 11 Jul 2016 13:32:19 GMT" }, { "version": "v2", "created": "Mon, 31 Oct 2016 16:11:21 GMT" } ]
2016-11-01T00:00:00
[ [ "Gonçalves", "Gabriel Resende", "" ], [ "da Silva", "Sirlene Pio Gomes", "" ], [ "Menotti", "David", "" ], [ "Schwartz", "William Robson", "" ] ]
TITLE: Benchmark for License Plate Character Segmentation ABSTRACT: Automatic License Plate Recognition (ALPR) has been the focus of many researches in the past years. In general, ALPR is divided into the following problems: detection of on-track vehicles, license plates detection, segmention of license plate characters and optical character recognition (OCR). Even though commercial solutions are available for controlled acquisition conditions, e.g., the entrance of a parking lot, ALPR is still an open problem when dealing with data acquired from uncontrolled environments, such as roads and highways when relying only on imaging sensors. Due to the multiple orientations and scales of the license plates captured by the camera, a very challenging task of the ALPR is the License Plate Character Segmentation (LPCS) step, which effectiveness is required to be (near) optimal to achieve a high recognition rate by the OCR. To tackle the LPCS problem, this work proposes a novel benchmark composed of a dataset designed to focus specifically on the character segmentation step of the ALPR within an evaluation protocol. Furthermore, we propose the Jaccard-Centroid coefficient, a new evaluation measure more suitable than the Jaccard coefficient regarding the location of the bounding box within the ground-truth annotation. The dataset is composed of 2,000 Brazilian license plates consisting of 14,000 alphanumeric symbols and their corresponding bounding box annotations. We also present a new straightforward approach to perform LPCS efficiently. Finally, we provide an experimental evaluation for the dataset based on four LPCS approaches and demonstrate the importance of character segmentation for achieving an accurate OCR.
new_dataset
0.976333
1610.04834
Mohsen Ghafoorian
Mohsen Ghafoorian, Nico Karssemeijer, Tom Heskes, Inge van Uden, Clara Sanchez, Geert Litjens, Frank-Erik de Leeuw, Bram van Ginneken, Elena Marchiori and Bram Platel
Location Sensitive Deep Convolutional Neural Networks for Segmentation of White Matter Hyperintensities
13 pages, 8 figures
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The anatomical location of imaging features is of crucial importance for accurate diagnosis in many medical tasks. Convolutional neural networks (CNN) have had huge successes in computer vision, but they lack the natural ability to incorporate the anatomical location in their decision making process, hindering success in some medical image analysis tasks. In this paper, to integrate the anatomical location information into the network, we propose several deep CNN architectures that consider multi-scale patches or take explicit location features while training. We apply and compare the proposed architectures for segmentation of white matter hyperintensities in brain MR images on a large dataset. As a result, we observe that the CNNs that incorporate location information substantially outperform a conventional segmentation method with hand-crafted features as well as CNNs that do not integrate location information. On a test set of 46 scans, the best configuration of our networks obtained a Dice score of 0.791, compared to 0.797 for an independent human observer. Performance levels of the machine and the independent human observer were not statistically significantly different (p-value=0.17).
[ { "version": "v1", "created": "Sun, 16 Oct 2016 09:35:36 GMT" }, { "version": "v2", "created": "Sat, 29 Oct 2016 15:10:46 GMT" } ]
2016-11-01T00:00:00
[ [ "Ghafoorian", "Mohsen", "" ], [ "Karssemeijer", "Nico", "" ], [ "Heskes", "Tom", "" ], [ "van Uden", "Inge", "" ], [ "Sanchez", "Clara", "" ], [ "Litjens", "Geert", "" ], [ "de Leeuw", "Frank-Erik", "" ], [ "van Ginneken", "Bram", "" ], [ "Marchiori", "Elena", "" ], [ "Platel", "Bram", "" ] ]
TITLE: Location Sensitive Deep Convolutional Neural Networks for Segmentation of White Matter Hyperintensities ABSTRACT: The anatomical location of imaging features is of crucial importance for accurate diagnosis in many medical tasks. Convolutional neural networks (CNN) have had huge successes in computer vision, but they lack the natural ability to incorporate the anatomical location in their decision making process, hindering success in some medical image analysis tasks. In this paper, to integrate the anatomical location information into the network, we propose several deep CNN architectures that consider multi-scale patches or take explicit location features while training. We apply and compare the proposed architectures for segmentation of white matter hyperintensities in brain MR images on a large dataset. As a result, we observe that the CNNs that incorporate location information substantially outperform a conventional segmentation method with hand-crafted features as well as CNNs that do not integrate location information. On a test set of 46 scans, the best configuration of our networks obtained a Dice score of 0.791, compared to 0.797 for an independent human observer. Performance levels of the machine and the independent human observer were not statistically significantly different (p-value=0.17).
no_new_dataset
0.951818
1610.09451
Evan Sparks
Evan R. Sparks, Shivaram Venkataraman, Tomer Kaftan, Michael J. Franklin, Benjamin Recht
KeystoneML: Optimizing Pipelines for Large-Scale Advanced Analytics
null
null
null
null
cs.LG cs.DC
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Modern advanced analytics applications make use of machine learning techniques and contain multiple steps of domain-specific and general-purpose processing with high resource requirements. We present KeystoneML, a system that captures and optimizes the end-to-end large-scale machine learning applications for high-throughput training in a distributed environment with a high-level API. This approach offers increased ease of use and higher performance over existing systems for large scale learning. We demonstrate the effectiveness of KeystoneML in achieving high quality statistical accuracy and scalable training using real world datasets in several domains. By optimizing execution KeystoneML achieves up to 15x training throughput over unoptimized execution on a real image classification application.
[ { "version": "v1", "created": "Sat, 29 Oct 2016 04:21:24 GMT" } ]
2016-11-01T00:00:00
[ [ "Sparks", "Evan R.", "" ], [ "Venkataraman", "Shivaram", "" ], [ "Kaftan", "Tomer", "" ], [ "Franklin", "Michael J.", "" ], [ "Recht", "Benjamin", "" ] ]
TITLE: KeystoneML: Optimizing Pipelines for Large-Scale Advanced Analytics ABSTRACT: Modern advanced analytics applications make use of machine learning techniques and contain multiple steps of domain-specific and general-purpose processing with high resource requirements. We present KeystoneML, a system that captures and optimizes the end-to-end large-scale machine learning applications for high-throughput training in a distributed environment with a high-level API. This approach offers increased ease of use and higher performance over existing systems for large scale learning. We demonstrate the effectiveness of KeystoneML in achieving high quality statistical accuracy and scalable training using real world datasets in several domains. By optimizing execution KeystoneML achieves up to 15x training throughput over unoptimized execution on a real image classification application.
no_new_dataset
0.948106
1610.09462
Ye Liu
Ye Liu, Yuxuan Liang, Shuming Liu, David S. Rosenblum, and Yu Zheng
Predicting Urban Water Quality with Ubiquitous Data
null
null
null
null
cs.CY
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Urban water quality is of great importance to our daily lives. Prediction of urban water quality help control water pollution and protect human health. However, predicting the urban water quality is a challenging task since the water quality varies in urban spaces non-linearly and depends on multiple factors, such as meteorology, water usage patterns, and land uses. In this work, we forecast the water quality of a station over the next few hours from a data-driven perspective, using the water quality data and water hydraulic data reported by existing monitor stations and a variety of data sources we observed in the city, such as meteorology, pipe networks, structure of road networks, and point of interests (POIs). First, we identify the influential factors that affect the urban water quality via extensive experiments. Second, we present a multi-task multi-view learning method to fuse those multiple datasets from different domains into an unified learning model. We evaluate our method with real-world datasets, and the extensive experiments verify the advantages of our method over other baselines and demonstrate the effectiveness of our approach.
[ { "version": "v1", "created": "Sat, 29 Oct 2016 06:04:14 GMT" } ]
2016-11-01T00:00:00
[ [ "Liu", "Ye", "" ], [ "Liang", "Yuxuan", "" ], [ "Liu", "Shuming", "" ], [ "Rosenblum", "David S.", "" ], [ "Zheng", "Yu", "" ] ]
TITLE: Predicting Urban Water Quality with Ubiquitous Data ABSTRACT: Urban water quality is of great importance to our daily lives. Prediction of urban water quality help control water pollution and protect human health. However, predicting the urban water quality is a challenging task since the water quality varies in urban spaces non-linearly and depends on multiple factors, such as meteorology, water usage patterns, and land uses. In this work, we forecast the water quality of a station over the next few hours from a data-driven perspective, using the water quality data and water hydraulic data reported by existing monitor stations and a variety of data sources we observed in the city, such as meteorology, pipe networks, structure of road networks, and point of interests (POIs). First, we identify the influential factors that affect the urban water quality via extensive experiments. Second, we present a multi-task multi-view learning method to fuse those multiple datasets from different domains into an unified learning model. We evaluate our method with real-world datasets, and the extensive experiments verify the advantages of our method over other baselines and demonstrate the effectiveness of our approach.
no_new_dataset
0.947721
1610.09491
Kiarash Shaloudegi
Kiarash Shaloudegi, Andr\'as Gy\"orgy, Csaba Szepesv\'ari, and Wilsun Xu
SDP Relaxation with Randomized Rounding for Energy Disaggregation
null
null
null
null
cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We develop a scalable, computationally efficient method for the task of energy disaggregation for home appliance monitoring. In this problem the goal is to estimate the energy consumption of each appliance over time based on the total energy-consumption signal of a household. The current state of the art is to model the problem as inference in factorial HMMs, and use quadratic programming to find an approximate solution to the resulting quadratic integer program. Here we take a more principled approach, better suited to integer programming problems, and find an approximate optimum by combining convex semidefinite relaxations randomized rounding, as well as a scalable ADMM method that exploits the special structure of the resulting semidefinite program. Simulation results both in synthetic and real-world datasets demonstrate the superiority of our method.
[ { "version": "v1", "created": "Sat, 29 Oct 2016 11:48:28 GMT" } ]
2016-11-01T00:00:00
[ [ "Shaloudegi", "Kiarash", "" ], [ "György", "András", "" ], [ "Szepesvári", "Csaba", "" ], [ "Xu", "Wilsun", "" ] ]
TITLE: SDP Relaxation with Randomized Rounding for Energy Disaggregation ABSTRACT: We develop a scalable, computationally efficient method for the task of energy disaggregation for home appliance monitoring. In this problem the goal is to estimate the energy consumption of each appliance over time based on the total energy-consumption signal of a household. The current state of the art is to model the problem as inference in factorial HMMs, and use quadratic programming to find an approximate solution to the resulting quadratic integer program. Here we take a more principled approach, better suited to integer programming problems, and find an approximate optimum by combining convex semidefinite relaxations randomized rounding, as well as a scalable ADMM method that exploits the special structure of the resulting semidefinite program. Simulation results both in synthetic and real-world datasets demonstrate the superiority of our method.
no_new_dataset
0.941601
1610.09500
Yiming Lin
Yiming Lin and Hongzhi Wang and Jianzhong Li and Hong Gao
Efficient Entity Resolution on Heterogeneous Records
null
null
null
null
cs.DB
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Entity resolution (ER) is the problem of identifying and merging records that refer to the same real-world entity. In many scenarios, raw records are stored under heterogeneous environment. Specifically, the schemas of records may differ from each other. To leverage such records better, most existing work assume that schema matching and data exchange have been done to convert records under different schemas to those under a predefined schema. However, we observe that schema matching would lose information in some cases, which could be useful or even crucial to ER. To leverage sufficient information from heterogeneous sources, in this paper, we address several challenges of ER on heterogeneous records and show that none of existing similarity metrics or their transformations could be applied to find similar records under heterogeneous settings. Motivated by this, we design the similarity function and propose a novel framework to iteratively find records which refer to the same entity. Regarding efficiency, we build an index to generate candidates and accelerate similarity computation. Evaluations on real-world datasets show the effectiveness and efficiency of our methods.
[ { "version": "v1", "created": "Sat, 29 Oct 2016 12:51:52 GMT" } ]
2016-11-01T00:00:00
[ [ "Lin", "Yiming", "" ], [ "Wang", "Hongzhi", "" ], [ "Li", "Jianzhong", "" ], [ "Gao", "Hong", "" ] ]
TITLE: Efficient Entity Resolution on Heterogeneous Records ABSTRACT: Entity resolution (ER) is the problem of identifying and merging records that refer to the same real-world entity. In many scenarios, raw records are stored under heterogeneous environment. Specifically, the schemas of records may differ from each other. To leverage such records better, most existing work assume that schema matching and data exchange have been done to convert records under different schemas to those under a predefined schema. However, we observe that schema matching would lose information in some cases, which could be useful or even crucial to ER. To leverage sufficient information from heterogeneous sources, in this paper, we address several challenges of ER on heterogeneous records and show that none of existing similarity metrics or their transformations could be applied to find similar records under heterogeneous settings. Motivated by this, we design the similarity function and propose a novel framework to iteratively find records which refer to the same entity. Regarding efficiency, we build an index to generate candidates and accelerate similarity computation. Evaluations on real-world datasets show the effectiveness and efficiency of our methods.
no_new_dataset
0.950319
1610.09506
Yiming Lin
Yiming Lin and Hongzhi Wang and Jianzhong Li and Hong Gao
Data Source Selection for Information Integration in Big Data Era
null
null
null
null
cs.DB
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In Big data era, information integration often requires abundant data extracted from massive data sources. Due to a large number of data sources, data source selection plays a crucial role in information integration, since it is costly and even impossible to access all data sources. Data Source selection should consider both efficiency and effectiveness issues. For efficiency, the approach should achieve high performance and be scalability to fit large data source amount. From effectiveness aspect, data quality and overlapping of sources are to be considered, since data quality varies much from data sources, with significant differences in the accuracy and coverage of the data provided, and the overlapping of sources can even lower the quality of data integrated from selected data sources. In this paper, we study source selection problem in \textit{Big Data Era} and propose methods which can scale to datasets with up to millions of data sources and guarantee the quality of results. Motivated by this, we propose a new object function taking the expected number of true values a source can provide as a criteria to evaluate the contribution of a data source. Based on our proposed index we present a scalable algorithm and two pruning strategies to improve the efficiency without sacrificing precision. Experimental results on both real world and synthetic data sets show that our methods can select sources providing a large proportion of true values efficiently and can scale to massive data sources.
[ { "version": "v1", "created": "Sat, 29 Oct 2016 13:17:50 GMT" } ]
2016-11-01T00:00:00
[ [ "Lin", "Yiming", "" ], [ "Wang", "Hongzhi", "" ], [ "Li", "Jianzhong", "" ], [ "Gao", "Hong", "" ] ]
TITLE: Data Source Selection for Information Integration in Big Data Era ABSTRACT: In Big data era, information integration often requires abundant data extracted from massive data sources. Due to a large number of data sources, data source selection plays a crucial role in information integration, since it is costly and even impossible to access all data sources. Data Source selection should consider both efficiency and effectiveness issues. For efficiency, the approach should achieve high performance and be scalability to fit large data source amount. From effectiveness aspect, data quality and overlapping of sources are to be considered, since data quality varies much from data sources, with significant differences in the accuracy and coverage of the data provided, and the overlapping of sources can even lower the quality of data integrated from selected data sources. In this paper, we study source selection problem in \textit{Big Data Era} and propose methods which can scale to datasets with up to millions of data sources and guarantee the quality of results. Motivated by this, we propose a new object function taking the expected number of true values a source can provide as a criteria to evaluate the contribution of a data source. Based on our proposed index we present a scalable algorithm and two pruning strategies to improve the efficiency without sacrificing precision. Experimental results on both real world and synthetic data sets show that our methods can select sources providing a large proportion of true values efficiently and can scale to massive data sources.
no_new_dataset
0.95018
1610.09565
Mihaela Rosca
Mihaela Rosca, Thomas Breuel
Sequence-to-sequence neural network models for transliteration
null
null
null
null
cs.CL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Transliteration is a key component of machine translation systems and software internationalization. This paper demonstrates that neural sequence-to-sequence models obtain state of the art or close to state of the art results on existing datasets. In an effort to make machine transliteration accessible, we open source a new Arabic to English transliteration dataset and our trained models.
[ { "version": "v1", "created": "Sat, 29 Oct 2016 19:21:19 GMT" } ]
2016-11-01T00:00:00
[ [ "Rosca", "Mihaela", "" ], [ "Breuel", "Thomas", "" ] ]
TITLE: Sequence-to-sequence neural network models for transliteration ABSTRACT: Transliteration is a key component of machine translation systems and software internationalization. This paper demonstrates that neural sequence-to-sequence models obtain state of the art or close to state of the art results on existing datasets. In an effort to make machine transliteration accessible, we open source a new Arabic to English transliteration dataset and our trained models.
new_dataset
0.954308
1610.09582
Rushil Anirudh
Rushil Anirudh, Ahnaf Masroor, Pavan Turaga
Diversity Promoting Online Sampling for Streaming Video Summarization
Published at ICIP 2016
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Many applications benefit from sampling algorithms where a small number of well chosen samples are used to generalize different properties of a large dataset. In this paper, we use diverse sampling for streaming video summarization. Several emerging applications support streaming video, but existing summarization algorithms need access to the entire video which requires a lot of memory and computational power. We propose a memory efficient and computationally fast, online algorithm that uses competitive learning for diverse sampling. Our algorithm is a generalization of online K-means such that the cost function reduces clustering error, while also ensuring a diverse set of samples. The diversity is measured as the volume of a convex hull around the samples. Finally, the performance of the proposed algorithm is measured against human users for 50 videos in the VSUMM dataset. The algorithm performs better than batch mode summarization, while requiring significantly lower memory and computational requirements.
[ { "version": "v1", "created": "Sat, 29 Oct 2016 23:51:24 GMT" } ]
2016-11-01T00:00:00
[ [ "Anirudh", "Rushil", "" ], [ "Masroor", "Ahnaf", "" ], [ "Turaga", "Pavan", "" ] ]
TITLE: Diversity Promoting Online Sampling for Streaming Video Summarization ABSTRACT: Many applications benefit from sampling algorithms where a small number of well chosen samples are used to generalize different properties of a large dataset. In this paper, we use diverse sampling for streaming video summarization. Several emerging applications support streaming video, but existing summarization algorithms need access to the entire video which requires a lot of memory and computational power. We propose a memory efficient and computationally fast, online algorithm that uses competitive learning for diverse sampling. Our algorithm is a generalization of online K-means such that the cost function reduces clustering error, while also ensuring a diverse set of samples. The diversity is measured as the volume of a convex hull around the samples. Finally, the performance of the proposed algorithm is measured against human users for 50 videos in the VSUMM dataset. The algorithm performs better than batch mode summarization, while requiring significantly lower memory and computational requirements.
no_new_dataset
0.947332
1610.09615
Amir Adler
Amir Adler, Michael Elad and Michael Zibulevsky
Compressed Learning: A Deep Neural Network Approach
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Compressed Learning (CL) is a joint signal processing and machine learning framework for inference from a signal, using a small number of measurements obtained by linear projections of the signal. In this paper we present an end-to-end deep learning approach for CL, in which a network composed of fully-connected layers followed by convolutional layers perform the linear sensing and non-linear inference stages. During the training phase, the sensing matrix and the non-linear inference operator are jointly optimized, and the proposed approach outperforms state-of-the-art for the task of image classification. For example, at a sensing rate of 1% (only 8 measurements of 28 X 28 pixels images), the classification error for the MNIST handwritten digits dataset is 6.46% compared to 41.06% with state-of-the-art.
[ { "version": "v1", "created": "Sun, 30 Oct 2016 07:54:19 GMT" } ]
2016-11-01T00:00:00
[ [ "Adler", "Amir", "" ], [ "Elad", "Michael", "" ], [ "Zibulevsky", "Michael", "" ] ]
TITLE: Compressed Learning: A Deep Neural Network Approach ABSTRACT: Compressed Learning (CL) is a joint signal processing and machine learning framework for inference from a signal, using a small number of measurements obtained by linear projections of the signal. In this paper we present an end-to-end deep learning approach for CL, in which a network composed of fully-connected layers followed by convolutional layers perform the linear sensing and non-linear inference stages. During the training phase, the sensing matrix and the non-linear inference operator are jointly optimized, and the proposed approach outperforms state-of-the-art for the task of image classification. For example, at a sensing rate of 1% (only 8 measurements of 28 X 28 pixels images), the classification error for the MNIST handwritten digits dataset is 6.46% compared to 41.06% with state-of-the-art.
no_new_dataset
0.947186
1610.09639
Sajid Anwar
Sajid Anwar, Wonyong Sung
Compact Deep Convolutional Neural Networks With Coarse Pruning
null
null
null
null
cs.LG cs.NE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The learning capability of a neural network improves with increasing depth at higher computational costs. Wider layers with dense kernel connectivity patterns furhter increase this cost and may hinder real-time inference. We propose feature map and kernel level pruning for reducing the computational complexity of a deep convolutional neural network. Pruning feature maps reduces the width of a layer and hence does not need any sparse representation. Further, kernel pruning converts the dense connectivity pattern into a sparse one. Due to coarse nature, these pruning granularities can be exploited by GPUs and VLSI based implementations. We propose a simple and generic strategy to choose the least adversarial pruning masks for both granularities. The pruned networks are retrained which compensates the loss in accuracy. We obtain the best pruning ratios when we prune a network with both granularities. Experiments with the CIFAR-10 dataset show that more than 85% sparsity can be induced in the convolution layers with less than 1% increase in the missclassification rate of the baseline network.
[ { "version": "v1", "created": "Sun, 30 Oct 2016 11:57:20 GMT" } ]
2016-11-01T00:00:00
[ [ "Anwar", "Sajid", "" ], [ "Sung", "Wonyong", "" ] ]
TITLE: Compact Deep Convolutional Neural Networks With Coarse Pruning ABSTRACT: The learning capability of a neural network improves with increasing depth at higher computational costs. Wider layers with dense kernel connectivity patterns furhter increase this cost and may hinder real-time inference. We propose feature map and kernel level pruning for reducing the computational complexity of a deep convolutional neural network. Pruning feature maps reduces the width of a layer and hence does not need any sparse representation. Further, kernel pruning converts the dense connectivity pattern into a sparse one. Due to coarse nature, these pruning granularities can be exploited by GPUs and VLSI based implementations. We propose a simple and generic strategy to choose the least adversarial pruning masks for both granularities. The pruned networks are retrained which compensates the loss in accuracy. We obtain the best pruning ratios when we prune a network with both granularities. Experiments with the CIFAR-10 dataset show that more than 85% sparsity can be induced in the convolution layers with less than 1% increase in the missclassification rate of the baseline network.
no_new_dataset
0.950915
1610.09652
Kaihua Zhang
Kaihua Zhang, Qingshan Liu, and Ming-Hsuan Yang
Visual Tracking via Boolean Map Representations
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we present a simple yet effective Boolean map based representation that exploits connectivity cues for visual tracking. We describe a target object with histogram of oriented gradients and raw color features, of which each one is characterized by a set of Boolean maps generated by uniformly thresholding their values. The Boolean maps effectively encode multi-scale connectivity cues of the target with different granularities. The fine-grained Boolean maps capture spatially structural details that are effective for precise target localization while the coarse-grained ones encode global shape information that are robust to large target appearance variations. Finally, all the Boolean maps form together a robust representation that can be approximated by an explicit feature map of the intersection kernel, which is fed into a logistic regression classifier with online update, and the target location is estimated within a particle filter framework. The proposed representation scheme is computationally efficient and facilitates achieving favorable performance in terms of accuracy and robustness against the state-of-the-art tracking methods on a large benchmark dataset of 50 image sequences.
[ { "version": "v1", "created": "Sun, 30 Oct 2016 14:17:05 GMT" } ]
2016-11-01T00:00:00
[ [ "Zhang", "Kaihua", "" ], [ "Liu", "Qingshan", "" ], [ "Yang", "Ming-Hsuan", "" ] ]
TITLE: Visual Tracking via Boolean Map Representations ABSTRACT: In this paper, we present a simple yet effective Boolean map based representation that exploits connectivity cues for visual tracking. We describe a target object with histogram of oriented gradients and raw color features, of which each one is characterized by a set of Boolean maps generated by uniformly thresholding their values. The Boolean maps effectively encode multi-scale connectivity cues of the target with different granularities. The fine-grained Boolean maps capture spatially structural details that are effective for precise target localization while the coarse-grained ones encode global shape information that are robust to large target appearance variations. Finally, all the Boolean maps form together a robust representation that can be approximated by an explicit feature map of the intersection kernel, which is fed into a logistic regression classifier with online update, and the target location is estimated within a particle filter framework. The proposed representation scheme is computationally efficient and facilitates achieving favorable performance in terms of accuracy and robustness against the state-of-the-art tracking methods on a large benchmark dataset of 50 image sequences.
no_new_dataset
0.949059
1610.09778
Jingbo Shang
Jingbo Shang, Meng Jiang, Wenzhu Tong, Jinfeng Xiao, Jian Peng, Jiawei Han
DPPred: An Effective Prediction Framework with Concise Discriminative Patterns
null
null
null
null
cs.LG cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the literature, two series of models have been proposed to address prediction problems including classification and regression. Simple models, such as generalized linear models, have ordinary performance but strong interpretability on a set of simple features. The other series, including tree-based models, organize numerical, categorical and high dimensional features into a comprehensive structure with rich interpretable information in the data. In this paper, we propose a novel Discriminative Pattern-based Prediction framework (DPPred) to accomplish the prediction tasks by taking their advantages of both effectiveness and interpretability. Specifically, DPPred adopts the concise discriminative patterns that are on the prefix paths from the root to leaf nodes in the tree-based models. DPPred selects a limited number of the useful discriminative patterns by searching for the most effective pattern combination to fit generalized linear models. Extensive experiments show that in many scenarios, DPPred provides competitive accuracy with the state-of-the-art as well as the valuable interpretability for developers and experts. In particular, taking a clinical application dataset as a case study, our DPPred outperforms the baselines by using only 40 concise discriminative patterns out of a potentially exponentially large set of patterns.
[ { "version": "v1", "created": "Mon, 31 Oct 2016 03:43:04 GMT" } ]
2016-11-01T00:00:00
[ [ "Shang", "Jingbo", "" ], [ "Jiang", "Meng", "" ], [ "Tong", "Wenzhu", "" ], [ "Xiao", "Jinfeng", "" ], [ "Peng", "Jian", "" ], [ "Han", "Jiawei", "" ] ]
TITLE: DPPred: An Effective Prediction Framework with Concise Discriminative Patterns ABSTRACT: In the literature, two series of models have been proposed to address prediction problems including classification and regression. Simple models, such as generalized linear models, have ordinary performance but strong interpretability on a set of simple features. The other series, including tree-based models, organize numerical, categorical and high dimensional features into a comprehensive structure with rich interpretable information in the data. In this paper, we propose a novel Discriminative Pattern-based Prediction framework (DPPred) to accomplish the prediction tasks by taking their advantages of both effectiveness and interpretability. Specifically, DPPred adopts the concise discriminative patterns that are on the prefix paths from the root to leaf nodes in the tree-based models. DPPred selects a limited number of the useful discriminative patterns by searching for the most effective pattern combination to fit generalized linear models. Extensive experiments show that in many scenarios, DPPred provides competitive accuracy with the state-of-the-art as well as the valuable interpretability for developers and experts. In particular, taking a clinical application dataset as a case study, our DPPred outperforms the baselines by using only 40 concise discriminative patterns out of a potentially exponentially large set of patterns.
no_new_dataset
0.944893
1610.09893
Tao Qin Dr.
Xiang Li and Tao Qin and Jian Yang and Tie-Yan Liu
LightRNN: Memory and Computation-Efficient Recurrent Neural Networks
NIPS 2016
null
null
null
cs.CL cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recurrent neural networks (RNNs) have achieved state-of-the-art performances in many natural language processing tasks, such as language modeling and machine translation. However, when the vocabulary is large, the RNN model will become very big (e.g., possibly beyond the memory capacity of a GPU device) and its training will become very inefficient. In this work, we propose a novel technique to tackle this challenge. The key idea is to use 2-Component (2C) shared embedding for word representations. We allocate every word in the vocabulary into a table, each row of which is associated with a vector, and each column associated with another vector. Depending on its position in the table, a word is jointly represented by two components: a row vector and a column vector. Since the words in the same row share the row vector and the words in the same column share the column vector, we only need $2 \sqrt{|V|}$ vectors to represent a vocabulary of $|V|$ unique words, which are far less than the $|V|$ vectors required by existing approaches. Based on the 2-Component shared embedding, we design a new RNN algorithm and evaluate it using the language modeling task on several benchmark datasets. The results show that our algorithm significantly reduces the model size and speeds up the training process, without sacrifice of accuracy (it achieves similar, if not better, perplexity as compared to state-of-the-art language models). Remarkably, on the One-Billion-Word benchmark Dataset, our algorithm achieves comparable perplexity to previous language models, whilst reducing the model size by a factor of 40-100, and speeding up the training process by a factor of 2. We name our proposed algorithm \emph{LightRNN} to reflect its very small model size and very high training speed.
[ { "version": "v1", "created": "Mon, 31 Oct 2016 12:24:13 GMT" } ]
2016-11-01T00:00:00
[ [ "Li", "Xiang", "" ], [ "Qin", "Tao", "" ], [ "Yang", "Jian", "" ], [ "Liu", "Tie-Yan", "" ] ]
TITLE: LightRNN: Memory and Computation-Efficient Recurrent Neural Networks ABSTRACT: Recurrent neural networks (RNNs) have achieved state-of-the-art performances in many natural language processing tasks, such as language modeling and machine translation. However, when the vocabulary is large, the RNN model will become very big (e.g., possibly beyond the memory capacity of a GPU device) and its training will become very inefficient. In this work, we propose a novel technique to tackle this challenge. The key idea is to use 2-Component (2C) shared embedding for word representations. We allocate every word in the vocabulary into a table, each row of which is associated with a vector, and each column associated with another vector. Depending on its position in the table, a word is jointly represented by two components: a row vector and a column vector. Since the words in the same row share the row vector and the words in the same column share the column vector, we only need $2 \sqrt{|V|}$ vectors to represent a vocabulary of $|V|$ unique words, which are far less than the $|V|$ vectors required by existing approaches. Based on the 2-Component shared embedding, we design a new RNN algorithm and evaluate it using the language modeling task on several benchmark datasets. The results show that our algorithm significantly reduces the model size and speeds up the training process, without sacrifice of accuracy (it achieves similar, if not better, perplexity as compared to state-of-the-art language models). Remarkably, on the One-Billion-Word benchmark Dataset, our algorithm achieves comparable perplexity to previous language models, whilst reducing the model size by a factor of 40-100, and speeding up the training process by a factor of 2. We name our proposed algorithm \emph{LightRNN} to reflect its very small model size and very high training speed.
no_new_dataset
0.948728
1610.09984
Alessandro Epasto
Alessandro Epasto, Silvio Lattanzi, Sergei Vassilvitskii, Morteza Zadimoghaddam
Submodular Optimization over Sliding Windows
null
null
null
null
cs.DS
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Maximizing submodular functions under cardinality constraints lies at the core of numerous data mining and machine learning applications, including data diversification, data summarization, and coverage problems. In this work, we study this question in the context of data streams, where elements arrive one at a time, and we want to design low-memory and fast update-time algorithms that maintain a good solution. Specifically, we focus on the sliding window model, where we are asked to maintain a solution that considers only the last $W$ items. In this context, we provide the first non-trivial algorithm that maintains a provable approximation of the optimum using space sublinear in the size of the window. In particular we give a $\frac{1}{3} - \epsilon$ approximation algorithm that uses space polylogarithmic in the spread of the values of the elements, $\Phi$, and linear in the solution size $k$ for any constant $\epsilon > 0$ . At the same time, processing each element only requires a polylogarithmic number of evaluations of the function itself. When a better approximation is desired, we show a different algorithm that, at the cost of using more memory, provides a $\frac{1}{2} - \epsilon$ approximation and allows a tunable trade-off between average update time and space. This algorithm matches the best known approximation guarantees for submodular optimization in insertion-only streams, a less general formulation of the problem. We demonstrate the efficacy of the algorithms on a number of real world datasets, showing that their practical performance far exceeds the theoretical bounds. The algorithms preserve high quality solutions in streams with millions of items, while storing a negligible fraction of them.
[ { "version": "v1", "created": "Mon, 31 Oct 2016 15:48:24 GMT" } ]
2016-11-01T00:00:00
[ [ "Epasto", "Alessandro", "" ], [ "Lattanzi", "Silvio", "" ], [ "Vassilvitskii", "Sergei", "" ], [ "Zadimoghaddam", "Morteza", "" ] ]
TITLE: Submodular Optimization over Sliding Windows ABSTRACT: Maximizing submodular functions under cardinality constraints lies at the core of numerous data mining and machine learning applications, including data diversification, data summarization, and coverage problems. In this work, we study this question in the context of data streams, where elements arrive one at a time, and we want to design low-memory and fast update-time algorithms that maintain a good solution. Specifically, we focus on the sliding window model, where we are asked to maintain a solution that considers only the last $W$ items. In this context, we provide the first non-trivial algorithm that maintains a provable approximation of the optimum using space sublinear in the size of the window. In particular we give a $\frac{1}{3} - \epsilon$ approximation algorithm that uses space polylogarithmic in the spread of the values of the elements, $\Phi$, and linear in the solution size $k$ for any constant $\epsilon > 0$ . At the same time, processing each element only requires a polylogarithmic number of evaluations of the function itself. When a better approximation is desired, we show a different algorithm that, at the cost of using more memory, provides a $\frac{1}{2} - \epsilon$ approximation and allows a tunable trade-off between average update time and space. This algorithm matches the best known approximation guarantees for submodular optimization in insertion-only streams, a less general formulation of the problem. We demonstrate the efficacy of the algorithms on a number of real world datasets, showing that their practical performance far exceeds the theoretical bounds. The algorithms preserve high quality solutions in streams with millions of items, while storing a negligible fraction of them.
no_new_dataset
0.940298
1610.10048
Arulkumar Subramaniam
Arulkumar Subramaniam, Vismay Patel, Ashish Mishra, Prashanth Balasubramanian, Anurag Mittal
Bi-modal First Impressions Recognition using Temporally Ordered Deep Audio and Stochastic Visual Features
to be published in: ECCV 2016 Workshops proceedings (Apparent Personality Analysis)
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a novel approach for First Impressions Recognition in terms of the Big Five personality-traits from short videos. The Big Five personality traits is a model to describe human personality using five broad categories: Extraversion, Agreeableness, Conscientiousness, Neuroticism and Openness. We train two bi-modal end-to-end deep neural network architectures using temporally ordered audio and novel stochastic visual features from few frames, without over-fitting. We empirically show that the trained models perform exceptionally well, even after training from a small sub-portions of inputs. Our method is evaluated in ChaLearn LAP 2016 Apparent Personality Analysis (APA) competition using ChaLearn LAP APA2016 dataset and achieved excellent performance.
[ { "version": "v1", "created": "Mon, 31 Oct 2016 18:21:13 GMT" } ]
2016-11-01T00:00:00
[ [ "Subramaniam", "Arulkumar", "" ], [ "Patel", "Vismay", "" ], [ "Mishra", "Ashish", "" ], [ "Balasubramanian", "Prashanth", "" ], [ "Mittal", "Anurag", "" ] ]
TITLE: Bi-modal First Impressions Recognition using Temporally Ordered Deep Audio and Stochastic Visual Features ABSTRACT: We propose a novel approach for First Impressions Recognition in terms of the Big Five personality-traits from short videos. The Big Five personality traits is a model to describe human personality using five broad categories: Extraversion, Agreeableness, Conscientiousness, Neuroticism and Openness. We train two bi-modal end-to-end deep neural network architectures using temporally ordered audio and novel stochastic visual features from few frames, without over-fitting. We empirically show that the trained models perform exceptionally well, even after training from a small sub-portions of inputs. Our method is evaluated in ChaLearn LAP 2016 Apparent Personality Analysis (APA) competition using ChaLearn LAP APA2016 dataset and achieved excellent performance.
no_new_dataset
0.951233
1610.10064
Muhammad Bilal Zafar
Miguel Ferreira, Muhammad Bilal Zafar, Krishna P. Gummadi
The Case for Temporal Transparency: Detecting Policy Change Events in Black-Box Decision Making Systems
null
null
null
null
stat.ML cs.CY
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Bringing transparency to black-box decision making systems (DMS) has been a topic of increasing research interest in recent years. Traditional active and passive approaches to make these systems transparent are often limited by scalability and/or feasibility issues. In this paper, we propose a new notion of black-box DMS transparency, named, temporal transparency, whose goal is to detect if/when the DMS policy changes over time, and is mostly invariant to the drawbacks of traditional approaches. We map our notion of temporal transparency to time series changepoint detection methods, and develop a framework to detect policy changes in real-world DMS's. Experiments on New York Stop-question-and-frisk dataset reveal a number of publicly announced and unannounced policy changes, highlighting the utility of our framework.
[ { "version": "v1", "created": "Mon, 31 Oct 2016 18:54:56 GMT" } ]
2016-11-01T00:00:00
[ [ "Ferreira", "Miguel", "" ], [ "Zafar", "Muhammad Bilal", "" ], [ "Gummadi", "Krishna P.", "" ] ]
TITLE: The Case for Temporal Transparency: Detecting Policy Change Events in Black-Box Decision Making Systems ABSTRACT: Bringing transparency to black-box decision making systems (DMS) has been a topic of increasing research interest in recent years. Traditional active and passive approaches to make these systems transparent are often limited by scalability and/or feasibility issues. In this paper, we propose a new notion of black-box DMS transparency, named, temporal transparency, whose goal is to detect if/when the DMS policy changes over time, and is mostly invariant to the drawbacks of traditional approaches. We map our notion of temporal transparency to time series changepoint detection methods, and develop a framework to detect policy changes in real-world DMS's. Experiments on New York Stop-question-and-frisk dataset reveal a number of publicly announced and unannounced policy changes, highlighting the utility of our framework.
no_new_dataset
0.954393
1409.5253
Valerio Gemmetto
Valerio Gemmetto and Diego Garlaschelli
Multiplexity versus correlation: the role of local constraints in real multiplexes
32 pages, 6 figures
Scientific Reports 5, 9120 (2015)
10.1038/srep09120
null
physics.soc-ph cs.SI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Several real-world systems can be represented as multi-layer complex networks, i.e. in terms of a superposition of various graphs, each related to a different mode of connection between nodes. Hence, the definition of proper mathematical quantities aiming at capturing the level of complexity of those systems is required. Various attempts have been made to measure the empirical dependencies between the layers of a multiplex, for both binary and weighted networks. In the simplest case, such dependencies are measured via correlation-based metrics: we show that this is equivalent to the use of completely homogeneous benchmarks specifying only global constraints, such as the total number of links in each layer. However, these approaches do not take into account the heterogeneity in the degree and strength distributions, which are instead a fundamental feature of real-world multiplexes. In this work, we compare the observed dependencies between layers with the expected values obtained from reference models that appropriately control for the observed heterogeneity in the degree and strength distributions. This leads to novel multiplexity measures that we test on different datasets, i.e. the International Trade Network (ITN) and the European Airport Network (EAN). Our findings confirm that the use of homogeneous benchmarks can lead to misleading results, and furthermore highlight the important role played by the distribution of hubs across layers.
[ { "version": "v1", "created": "Thu, 18 Sep 2014 10:49:45 GMT" } ]
2016-10-31T00:00:00
[ [ "Gemmetto", "Valerio", "" ], [ "Garlaschelli", "Diego", "" ] ]
TITLE: Multiplexity versus correlation: the role of local constraints in real multiplexes ABSTRACT: Several real-world systems can be represented as multi-layer complex networks, i.e. in terms of a superposition of various graphs, each related to a different mode of connection between nodes. Hence, the definition of proper mathematical quantities aiming at capturing the level of complexity of those systems is required. Various attempts have been made to measure the empirical dependencies between the layers of a multiplex, for both binary and weighted networks. In the simplest case, such dependencies are measured via correlation-based metrics: we show that this is equivalent to the use of completely homogeneous benchmarks specifying only global constraints, such as the total number of links in each layer. However, these approaches do not take into account the heterogeneity in the degree and strength distributions, which are instead a fundamental feature of real-world multiplexes. In this work, we compare the observed dependencies between layers with the expected values obtained from reference models that appropriately control for the observed heterogeneity in the degree and strength distributions. This leads to novel multiplexity measures that we test on different datasets, i.e. the International Trade Network (ITN) and the European Airport Network (EAN). Our findings confirm that the use of homogeneous benchmarks can lead to misleading results, and furthermore highlight the important role played by the distribution of hubs across layers.
no_new_dataset
0.944893
1601.06180
Robert Peharz
Robert Peharz, Robert Gens, Franz Pernkopf, Pedro Domingos
On the Latent Variable Interpretation in Sum-Product Networks
Revised version, accepted for publication in IEEE Transactions on Machine Intelligence and Pattern Analysis (TPAMI). Shortened and revised Section 4: Thanks to our reviewers, pointing out that Theorem 2 holds for selective SPNs. Added paragraph in Section 2.1, relating sizes of original/augmented SPNs. Fixed typos, rephrased sentences, revised references
null
null
null
cs.AI cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
One of the central themes in Sum-Product networks (SPNs) is the interpretation of sum nodes as marginalized latent variables (LVs). This interpretation yields an increased syntactic or semantic structure, allows the application of the EM algorithm and to efficiently perform MPE inference. In literature, the LV interpretation was justified by explicitly introducing the indicator variables corresponding to the LVs' states. However, as pointed out in this paper, this approach is in conflict with the completeness condition in SPNs and does not fully specify the probabilistic model. We propose a remedy for this problem by modifying the original approach for introducing the LVs, which we call SPN augmentation. We discuss conditional independencies in augmented SPNs, formally establish the probabilistic interpretation of the sum-weights and give an interpretation of augmented SPNs as Bayesian networks. Based on these results, we find a sound derivation of the EM algorithm for SPNs. Furthermore, the Viterbi-style algorithm for MPE proposed in literature was never proven to be correct. We show that this is indeed a correct algorithm, when applied to selective SPNs, and in particular when applied to augmented SPNs. Our theoretical results are confirmed in experiments on synthetic data and 103 real-world datasets.
[ { "version": "v1", "created": "Fri, 22 Jan 2016 21:40:33 GMT" }, { "version": "v2", "created": "Fri, 28 Oct 2016 07:54:35 GMT" } ]
2016-10-31T00:00:00
[ [ "Peharz", "Robert", "" ], [ "Gens", "Robert", "" ], [ "Pernkopf", "Franz", "" ], [ "Domingos", "Pedro", "" ] ]
TITLE: On the Latent Variable Interpretation in Sum-Product Networks ABSTRACT: One of the central themes in Sum-Product networks (SPNs) is the interpretation of sum nodes as marginalized latent variables (LVs). This interpretation yields an increased syntactic or semantic structure, allows the application of the EM algorithm and to efficiently perform MPE inference. In literature, the LV interpretation was justified by explicitly introducing the indicator variables corresponding to the LVs' states. However, as pointed out in this paper, this approach is in conflict with the completeness condition in SPNs and does not fully specify the probabilistic model. We propose a remedy for this problem by modifying the original approach for introducing the LVs, which we call SPN augmentation. We discuss conditional independencies in augmented SPNs, formally establish the probabilistic interpretation of the sum-weights and give an interpretation of augmented SPNs as Bayesian networks. Based on these results, we find a sound derivation of the EM algorithm for SPNs. Furthermore, the Viterbi-style algorithm for MPE proposed in literature was never proven to be correct. We show that this is indeed a correct algorithm, when applied to selective SPNs, and in particular when applied to augmented SPNs. Our theoretical results are confirmed in experiments on synthetic data and 103 real-world datasets.
no_new_dataset
0.949995
1606.08513
Tomasz Jurczyk
Tomasz Jurczyk, Michael Zhai, Jinho D. Choi
SelQA: A New Benchmark for Selection-based Question Answering
null
null
null
null
cs.CL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper presents a new selection-based question answering dataset, SelQA. The dataset consists of questions generated through crowdsourcing and sentence length answers that are drawn from the ten most prevalent topics in the English Wikipedia. We introduce a corpus annotation scheme that enhances the generation of large, diverse, and challenging datasets by explicitly aiming to reduce word co-occurrences between the question and answers. Our annotation scheme is composed of a series of crowdsourcing tasks with a view to more effectively utilize crowdsourcing in the creation of question answering datasets in various domains. Several systems are compared on the tasks of answer sentence selection and answer triggering, providing strong baseline results for future work to improve upon.
[ { "version": "v1", "created": "Mon, 27 Jun 2016 23:48:16 GMT" }, { "version": "v2", "created": "Wed, 12 Oct 2016 16:36:02 GMT" }, { "version": "v3", "created": "Fri, 28 Oct 2016 01:20:19 GMT" } ]
2016-10-31T00:00:00
[ [ "Jurczyk", "Tomasz", "" ], [ "Zhai", "Michael", "" ], [ "Choi", "Jinho D.", "" ] ]
TITLE: SelQA: A New Benchmark for Selection-based Question Answering ABSTRACT: This paper presents a new selection-based question answering dataset, SelQA. The dataset consists of questions generated through crowdsourcing and sentence length answers that are drawn from the ten most prevalent topics in the English Wikipedia. We introduce a corpus annotation scheme that enhances the generation of large, diverse, and challenging datasets by explicitly aiming to reduce word co-occurrences between the question and answers. Our annotation scheme is composed of a series of crowdsourcing tasks with a view to more effectively utilize crowdsourcing in the creation of question answering datasets in various domains. Several systems are compared on the tasks of answer sentence selection and answer triggering, providing strong baseline results for future work to improve upon.
new_dataset
0.952706
1607.02046
Gr\'egory Rogez
Gr\'egory Rogez and Cordelia Schmid
MoCap-guided Data Augmentation for 3D Pose Estimation in the Wild
9 pages, accepted to appear in NIPS 2016
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper addresses the problem of 3D human pose estimation in the wild. A significant challenge is the lack of training data, i.e., 2D images of humans annotated with 3D poses. Such data is necessary to train state-of-the-art CNN architectures. Here, we propose a solution to generate a large set of photorealistic synthetic images of humans with 3D pose annotations. We introduce an image-based synthesis engine that artificially augments a dataset of real images with 2D human pose annotations using 3D Motion Capture (MoCap) data. Given a candidate 3D pose our algorithm selects for each joint an image whose 2D pose locally matches the projected 3D pose. The selected images are then combined to generate a new synthetic image by stitching local image patches in a kinematically constrained manner. The resulting images are used to train an end-to-end CNN for full-body 3D pose estimation. We cluster the training data into a large number of pose classes and tackle pose estimation as a K-way classification problem. Such an approach is viable only with large training sets such as ours. Our method outperforms the state of the art in terms of 3D pose estimation in controlled environments (Human3.6M) and shows promising results for in-the-wild images (LSP). This demonstrates that CNNs trained on artificial images generalize well to real images.
[ { "version": "v1", "created": "Thu, 7 Jul 2016 15:30:05 GMT" }, { "version": "v2", "created": "Fri, 28 Oct 2016 12:43:51 GMT" } ]
2016-10-31T00:00:00
[ [ "Rogez", "Grégory", "" ], [ "Schmid", "Cordelia", "" ] ]
TITLE: MoCap-guided Data Augmentation for 3D Pose Estimation in the Wild ABSTRACT: This paper addresses the problem of 3D human pose estimation in the wild. A significant challenge is the lack of training data, i.e., 2D images of humans annotated with 3D poses. Such data is necessary to train state-of-the-art CNN architectures. Here, we propose a solution to generate a large set of photorealistic synthetic images of humans with 3D pose annotations. We introduce an image-based synthesis engine that artificially augments a dataset of real images with 2D human pose annotations using 3D Motion Capture (MoCap) data. Given a candidate 3D pose our algorithm selects for each joint an image whose 2D pose locally matches the projected 3D pose. The selected images are then combined to generate a new synthetic image by stitching local image patches in a kinematically constrained manner. The resulting images are used to train an end-to-end CNN for full-body 3D pose estimation. We cluster the training data into a large number of pose classes and tackle pose estimation as a K-way classification problem. Such an approach is viable only with large training sets such as ours. Our method outperforms the state of the art in terms of 3D pose estimation in controlled environments (Human3.6M) and shows promising results for in-the-wild images (LSP). This demonstrates that CNNs trained on artificial images generalize well to real images.
no_new_dataset
0.946051
1609.08777
Kazuya Kawakami
Kazuya Kawakami, Chris Dyer, Bryan R. Routledge, Noah A. Smith
Character Sequence Models for ColorfulWords
null
null
null
null
cs.CL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a neural network architecture to predict a point in color space from the sequence of characters in the color's name. Using large scale color--name pairs obtained from an online color design forum, we evaluate our model on a "color Turing test" and find that, given a name, the colors predicted by our model are preferred by annotators to color names created by humans. Our datasets and demo system are available online at colorlab.us.
[ { "version": "v1", "created": "Wed, 28 Sep 2016 05:41:18 GMT" }, { "version": "v2", "created": "Fri, 28 Oct 2016 16:08:36 GMT" } ]
2016-10-31T00:00:00
[ [ "Kawakami", "Kazuya", "" ], [ "Dyer", "Chris", "" ], [ "Routledge", "Bryan R.", "" ], [ "Smith", "Noah A.", "" ] ]
TITLE: Character Sequence Models for ColorfulWords ABSTRACT: We present a neural network architecture to predict a point in color space from the sequence of characters in the color's name. Using large scale color--name pairs obtained from an online color design forum, we evaluate our model on a "color Turing test" and find that, given a name, the colors predicted by our model are preferred by annotators to color names created by humans. Our datasets and demo system are available online at colorlab.us.
no_new_dataset
0.943295
1610.09003
Carl Vondrick
Yusuf Aytar, Lluis Castrejon, Carl Vondrick, Hamed Pirsiavash, Antonio Torralba
Cross-Modal Scene Networks
See more at http://cmplaces.csail.mit.edu/. arXiv admin note: text overlap with arXiv:1607.07295
null
null
null
cs.CV cs.LG cs.MM
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
People can recognize scenes across many different modalities beyond natural images. In this paper, we investigate how to learn cross-modal scene representations that transfer across modalities. To study this problem, we introduce a new cross-modal scene dataset. While convolutional neural networks can categorize scenes well, they also learn an intermediate representation not aligned across modalities, which is undesirable for cross-modal transfer applications. We present methods to regularize cross-modal convolutional neural networks so that they have a shared representation that is agnostic of the modality. Our experiments suggest that our scene representation can help transfer representations across modalities for retrieval. Moreover, our visualizations suggest that units emerge in the shared representation that tend to activate on consistent concepts independently of the modality.
[ { "version": "v1", "created": "Thu, 27 Oct 2016 20:24:36 GMT" } ]
2016-10-31T00:00:00
[ [ "Aytar", "Yusuf", "" ], [ "Castrejon", "Lluis", "" ], [ "Vondrick", "Carl", "" ], [ "Pirsiavash", "Hamed", "" ], [ "Torralba", "Antonio", "" ] ]
TITLE: Cross-Modal Scene Networks ABSTRACT: People can recognize scenes across many different modalities beyond natural images. In this paper, we investigate how to learn cross-modal scene representations that transfer across modalities. To study this problem, we introduce a new cross-modal scene dataset. While convolutional neural networks can categorize scenes well, they also learn an intermediate representation not aligned across modalities, which is undesirable for cross-modal transfer applications. We present methods to regularize cross-modal convolutional neural networks so that they have a shared representation that is agnostic of the modality. Our experiments suggest that our scene representation can help transfer representations across modalities for retrieval. Moreover, our visualizations suggest that units emerge in the shared representation that tend to activate on consistent concepts independently of the modality.
new_dataset
0.956796
1610.09058
Riley Murray
Riley Murray and Samir Khuller and Megan Chao
Scheduling Distributed Clusters of Parallel Machines: Primal-Dual and LP-based Approximation Algorithms [Full Version]
A shorter version of this paper (one that omitted several proofs) appeared in the proceedings of the 2016 European Symposium on Algorithms
Leibniz International Proceedings in Informatics (LIPIcs), Volume 58, 2016, pages 68:1--68:17
10.4230/LIPIcs.ESA.2016.68
null
cs.DS
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Map-Reduce computing framework rose to prominence with datasets of such size that dozens of machines on a single cluster were needed for individual jobs. As datasets approach the exabyte scale, a single job may need distributed processing not only on multiple machines, but on multiple clusters. We consider a scheduling problem to minimize weighted average completion time of N jobs on M distributed clusters of parallel machines. In keeping with the scale of the problems motivating this work, we assume that (1) each job is divided into M "subjobs" and (2) distinct subjobs of a given job may be processed concurrently. When each cluster is a single machine, this is the NP-Hard concurrent open shop problem. A clear limitation of such a model is that a serial processing assumption sidesteps the issue of how different tasks of a given subjob might be processed in parallel. Our algorithms explicitly model clusters as pools of resources and effectively overcome this issue. Under a variety of parameter settings, we develop two constant factor approximation algorithms for this problem. The first algorithm uses an LP relaxation tailored to this problem from prior work. This LP-based algorithm provides strong performance guarantees. Our second algorithm exploits a surprisingly simple mapping to the special case of one machine per cluster. This mapping-based algorithm is combinatorial and extremely fast. These are the first constant factor approximations for this problem.
[ { "version": "v1", "created": "Fri, 28 Oct 2016 02:14:25 GMT" } ]
2016-10-31T00:00:00
[ [ "Murray", "Riley", "" ], [ "Khuller", "Samir", "" ], [ "Chao", "Megan", "" ] ]
TITLE: Scheduling Distributed Clusters of Parallel Machines: Primal-Dual and LP-based Approximation Algorithms [Full Version] ABSTRACT: The Map-Reduce computing framework rose to prominence with datasets of such size that dozens of machines on a single cluster were needed for individual jobs. As datasets approach the exabyte scale, a single job may need distributed processing not only on multiple machines, but on multiple clusters. We consider a scheduling problem to minimize weighted average completion time of N jobs on M distributed clusters of parallel machines. In keeping with the scale of the problems motivating this work, we assume that (1) each job is divided into M "subjobs" and (2) distinct subjobs of a given job may be processed concurrently. When each cluster is a single machine, this is the NP-Hard concurrent open shop problem. A clear limitation of such a model is that a serial processing assumption sidesteps the issue of how different tasks of a given subjob might be processed in parallel. Our algorithms explicitly model clusters as pools of resources and effectively overcome this issue. Under a variety of parameter settings, we develop two constant factor approximation algorithms for this problem. The first algorithm uses an LP relaxation tailored to this problem from prior work. This LP-based algorithm provides strong performance guarantees. Our second algorithm exploits a surprisingly simple mapping to the special case of one machine per cluster. This mapping-based algorithm is combinatorial and extremely fast. These are the first constant factor approximations for this problem.
no_new_dataset
0.942929
1610.09072
Felix X. Yu
Felix X. Yu, Ananda Theertha Suresh, Krzysztof Choromanski, Daniel Holtmann-Rice, Sanjiv Kumar
Orthogonal Random Features
NIPS 2016
null
null
null
cs.LG stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present an intriguing discovery related to Random Fourier Features: in Gaussian kernel approximation, replacing the random Gaussian matrix by a properly scaled random orthogonal matrix significantly decreases kernel approximation error. We call this technique Orthogonal Random Features (ORF), and provide theoretical and empirical justification for this behavior. Motivated by this discovery, we further propose Structured Orthogonal Random Features (SORF), which uses a class of structured discrete orthogonal matrices to speed up the computation. The method reduces the time cost from $\mathcal{O}(d^2)$ to $\mathcal{O}(d \log d)$, where $d$ is the data dimensionality, with almost no compromise in kernel approximation quality compared to ORF. Experiments on several datasets verify the effectiveness of ORF and SORF over the existing methods. We also provide discussions on using the same type of discrete orthogonal structure for a broader range of applications.
[ { "version": "v1", "created": "Fri, 28 Oct 2016 03:50:00 GMT" } ]
2016-10-31T00:00:00
[ [ "Yu", "Felix X.", "" ], [ "Suresh", "Ananda Theertha", "" ], [ "Choromanski", "Krzysztof", "" ], [ "Holtmann-Rice", "Daniel", "" ], [ "Kumar", "Sanjiv", "" ] ]
TITLE: Orthogonal Random Features ABSTRACT: We present an intriguing discovery related to Random Fourier Features: in Gaussian kernel approximation, replacing the random Gaussian matrix by a properly scaled random orthogonal matrix significantly decreases kernel approximation error. We call this technique Orthogonal Random Features (ORF), and provide theoretical and empirical justification for this behavior. Motivated by this discovery, we further propose Structured Orthogonal Random Features (SORF), which uses a class of structured discrete orthogonal matrices to speed up the computation. The method reduces the time cost from $\mathcal{O}(d^2)$ to $\mathcal{O}(d \log d)$, where $d$ is the data dimensionality, with almost no compromise in kernel approximation quality compared to ORF. Experiments on several datasets verify the effectiveness of ORF and SORF over the existing methods. We also provide discussions on using the same type of discrete orthogonal structure for a broader range of applications.
no_new_dataset
0.953188
1610.09274
Guang-He Lee
Guang-He Lee, Shao-Wen Yang, Shou-De Lin
Toward Implicit Sample Noise Modeling: Deviation-driven Matrix Factorization
6 pages + 1 reference page
null
null
null
cs.LG cs.IR stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The objective function of a matrix factorization model usually aims to minimize the average of a regression error contributed by each element. However, given the existence of stochastic noises, the implicit deviations of sample data from their true values are almost surely diverse, which makes each data point not equally suitable for fitting a model. In this case, simply averaging the cost among data in the objective function is not ideal. Intuitively we would like to emphasize more on the reliable instances (i.e., those contain smaller noise) while training a model. Motivated by such observation, we derive our formula from a theoretical framework for optimal weighting under heteroscedastic noise distribution. Specifically, by modeling and learning the deviation of data, we design a novel matrix factorization model. Our model has two advantages. First, it jointly learns the deviation and conducts dynamic reweighting of instances, allowing the model to converge to a better solution. Second, during learning the deviated instances are assigned lower weights, which leads to faster convergence since the model does not need to overfit the noise. The experiments are conducted in clean recommendation and noisy sensor datasets to test the effectiveness of the model in various scenarios. The results show that our model outperforms the state-of-the-art factorization and deep learning models in both accuracy and efficiency.
[ { "version": "v1", "created": "Fri, 28 Oct 2016 15:33:25 GMT" } ]
2016-10-31T00:00:00
[ [ "Lee", "Guang-He", "" ], [ "Yang", "Shao-Wen", "" ], [ "Lin", "Shou-De", "" ] ]
TITLE: Toward Implicit Sample Noise Modeling: Deviation-driven Matrix Factorization ABSTRACT: The objective function of a matrix factorization model usually aims to minimize the average of a regression error contributed by each element. However, given the existence of stochastic noises, the implicit deviations of sample data from their true values are almost surely diverse, which makes each data point not equally suitable for fitting a model. In this case, simply averaging the cost among data in the objective function is not ideal. Intuitively we would like to emphasize more on the reliable instances (i.e., those contain smaller noise) while training a model. Motivated by such observation, we derive our formula from a theoretical framework for optimal weighting under heteroscedastic noise distribution. Specifically, by modeling and learning the deviation of data, we design a novel matrix factorization model. Our model has two advantages. First, it jointly learns the deviation and conducts dynamic reweighting of instances, allowing the model to converge to a better solution. Second, during learning the deviated instances are assigned lower weights, which leads to faster convergence since the model does not need to overfit the noise. The experiments are conducted in clean recommendation and noisy sensor datasets to test the effectiveness of the model in various scenarios. The results show that our model outperforms the state-of-the-art factorization and deep learning models in both accuracy and efficiency.
no_new_dataset
0.946101
1610.09300
Antoine Gautier
Antoine Gautier, Quynh Nguyen and Matthias Hein
Globally Optimal Training of Generalized Polynomial Neural Networks with Nonlinear Spectral Methods
Long version of NIPS 2016 paper
null
null
null
cs.LG math.OC stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The optimization problem behind neural networks is highly non-convex. Training with stochastic gradient descent and variants requires careful parameter tuning and provides no guarantee to achieve the global optimum. In contrast we show under quite weak assumptions on the data that a particular class of feedforward neural networks can be trained globally optimal with a linear convergence rate with our nonlinear spectral method. Up to our knowledge this is the first practically feasible method which achieves such a guarantee. While the method can in principle be applied to deep networks, we restrict ourselves for simplicity in this paper to one and two hidden layer networks. Our experiments confirm that these models are rich enough to achieve good performance on a series of real-world datasets.
[ { "version": "v1", "created": "Fri, 28 Oct 2016 16:28:23 GMT" } ]
2016-10-31T00:00:00
[ [ "Gautier", "Antoine", "" ], [ "Nguyen", "Quynh", "" ], [ "Hein", "Matthias", "" ] ]
TITLE: Globally Optimal Training of Generalized Polynomial Neural Networks with Nonlinear Spectral Methods ABSTRACT: The optimization problem behind neural networks is highly non-convex. Training with stochastic gradient descent and variants requires careful parameter tuning and provides no guarantee to achieve the global optimum. In contrast we show under quite weak assumptions on the data that a particular class of feedforward neural networks can be trained globally optimal with a linear convergence rate with our nonlinear spectral method. Up to our knowledge this is the first practically feasible method which achieves such a guarantee. While the method can in principle be applied to deep networks, we restrict ourselves for simplicity in this paper to one and two hidden layer networks. Our experiments confirm that these models are rich enough to achieve good performance on a series of real-world datasets.
no_new_dataset
0.946498
1610.09334
Seungryul Baek
Seungryul Baek, Kwang In Kim, Tae-Kyun Kim
Real-time Online Action Detection Forests using Spatio-temporal Contexts
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Online action detection (OAD) is challenging since 1) robust yet computationally expensive features cannot be straightforwardly used due to the real-time processing requirements and 2) the localization and classification of actions have to be performed even before they are fully observed. We propose a new random forest (RF)-based online action detection framework that addresses these challenges. Our algorithm uses computationally efficient skeletal joint features. High accuracy is achieved by using robust convolutional neural network (CNN)-based features which are extracted from the raw RGBD images, plus the temporal relationships between the current frame of interest, and the past and future frames. While these high-quality features are not available in real-time testing scenario, we demonstrate that they can be effectively exploited in training RF classifiers: We use these spatio-temporal contexts to craft RF's new split functions improving RFs' leaf node statistics. Experiments with challenging MSRAction3D, G3D, and OAD datasets demonstrate that our algorithm significantly improves the accuracy over the state-of-the-art online action detection algorithms while achieving the real-time efficiency of existing skeleton-based RF classifiers.
[ { "version": "v1", "created": "Fri, 28 Oct 2016 18:15:31 GMT" } ]
2016-10-31T00:00:00
[ [ "Baek", "Seungryul", "" ], [ "Kim", "Kwang In", "" ], [ "Kim", "Tae-Kyun", "" ] ]
TITLE: Real-time Online Action Detection Forests using Spatio-temporal Contexts ABSTRACT: Online action detection (OAD) is challenging since 1) robust yet computationally expensive features cannot be straightforwardly used due to the real-time processing requirements and 2) the localization and classification of actions have to be performed even before they are fully observed. We propose a new random forest (RF)-based online action detection framework that addresses these challenges. Our algorithm uses computationally efficient skeletal joint features. High accuracy is achieved by using robust convolutional neural network (CNN)-based features which are extracted from the raw RGBD images, plus the temporal relationships between the current frame of interest, and the past and future frames. While these high-quality features are not available in real-time testing scenario, we demonstrate that they can be effectively exploited in training RF classifiers: We use these spatio-temporal contexts to craft RF's new split functions improving RFs' leaf node statistics. Experiments with challenging MSRAction3D, G3D, and OAD datasets demonstrate that our algorithm significantly improves the accuracy over the state-of-the-art online action detection algorithms while achieving the real-time efficiency of existing skeleton-based RF classifiers.
no_new_dataset
0.942981
1610.08851
Andru Putra Twinanda
Andru P. Twinanda, Didier Mutter, Jacques Marescaux, Michel de Mathelin, Nicolas Padoy
Single- and Multi-Task Architectures for Tool Presence Detection Challenge at M2CAI 2016
The dataset is available at http://camma.u-strasbg.fr/m2cai2016/ . arXiv admin note: text overlap with arXiv:1610.08844
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The tool presence detection challenge at M2CAI 2016 consists of identifying the presence/absence of seven surgical tools in the images of cholecystectomy videos. Here, we propose to use deep architectures that are based on our previous work where we presented several architectures to perform multiple recognition tasks on laparoscopic videos. In this technical report, we present the tool presence detection results using two architectures: (1) a single-task architecture designed to perform solely the tool presence detection task and (2) a multi-task architecture designed to perform jointly phase recognition and tool presence detection. The results show that the multi-task network only slightly improves the tool presence detection results. In constrast, a significant improvement is obtained when there are more data available to train the networks. This significant improvement can be regarded as a call for action for other institutions to start working toward publishing more datasets into the community, so that better models could be generated to perform the task.
[ { "version": "v1", "created": "Thu, 27 Oct 2016 15:51:53 GMT" } ]
2016-10-30T00:00:00
[ [ "Twinanda", "Andru P.", "" ], [ "Mutter", "Didier", "" ], [ "Marescaux", "Jacques", "" ], [ "de Mathelin", "Michel", "" ], [ "Padoy", "Nicolas", "" ] ]
TITLE: Single- and Multi-Task Architectures for Tool Presence Detection Challenge at M2CAI 2016 ABSTRACT: The tool presence detection challenge at M2CAI 2016 consists of identifying the presence/absence of seven surgical tools in the images of cholecystectomy videos. Here, we propose to use deep architectures that are based on our previous work where we presented several architectures to perform multiple recognition tasks on laparoscopic videos. In this technical report, we present the tool presence detection results using two architectures: (1) a single-task architecture designed to perform solely the tool presence detection task and (2) a multi-task architecture designed to perform jointly phase recognition and tool presence detection. The results show that the multi-task network only slightly improves the tool presence detection results. In constrast, a significant improvement is obtained when there are more data available to train the networks. This significant improvement can be regarded as a call for action for other institutions to start working toward publishing more datasets into the community, so that better models could be generated to perform the task.
no_new_dataset
0.947235
1303.4778
Eva Dyer
Eva L. Dyer, Aswin C. Sankaranarayanan, Richard G. Baraniuk
Greedy Feature Selection for Subspace Clustering
32 pages, 7 figures, 1 table
Journal of Machine Learning Research, Vol.14, Issue 1, pp. 2487-2517, January 2013
null
null
cs.LG math.NA stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Unions of subspaces provide a powerful generalization to linear subspace models for collections of high-dimensional data. To learn a union of subspaces from a collection of data, sets of signals in the collection that belong to the same subspace must be identified in order to obtain accurate estimates of the subspace structures present in the data. Recently, sparse recovery methods have been shown to provide a provable and robust strategy for exact feature selection (EFS)--recovering subsets of points from the ensemble that live in the same subspace. In parallel with recent studies of EFS with L1-minimization, in this paper, we develop sufficient conditions for EFS with a greedy method for sparse signal recovery known as orthogonal matching pursuit (OMP). Following our analysis, we provide an empirical study of feature selection strategies for signals living on unions of subspaces and characterize the gap between sparse recovery methods and nearest neighbor (NN)-based approaches. In particular, we demonstrate that sparse recovery methods provide significant advantages over NN methods and the gap between the two approaches is particularly pronounced when the sampling of subspaces in the dataset is sparse. Our results suggest that OMP may be employed to reliably recover exact feature sets in a number of regimes where NN approaches fail to reveal the subspace membership of points in the ensemble.
[ { "version": "v1", "created": "Tue, 19 Mar 2013 22:17:20 GMT" }, { "version": "v2", "created": "Wed, 3 Jul 2013 19:07:34 GMT" } ]
2016-10-28T00:00:00
[ [ "Dyer", "Eva L.", "" ], [ "Sankaranarayanan", "Aswin C.", "" ], [ "Baraniuk", "Richard G.", "" ] ]
TITLE: Greedy Feature Selection for Subspace Clustering ABSTRACT: Unions of subspaces provide a powerful generalization to linear subspace models for collections of high-dimensional data. To learn a union of subspaces from a collection of data, sets of signals in the collection that belong to the same subspace must be identified in order to obtain accurate estimates of the subspace structures present in the data. Recently, sparse recovery methods have been shown to provide a provable and robust strategy for exact feature selection (EFS)--recovering subsets of points from the ensemble that live in the same subspace. In parallel with recent studies of EFS with L1-minimization, in this paper, we develop sufficient conditions for EFS with a greedy method for sparse signal recovery known as orthogonal matching pursuit (OMP). Following our analysis, we provide an empirical study of feature selection strategies for signals living on unions of subspaces and characterize the gap between sparse recovery methods and nearest neighbor (NN)-based approaches. In particular, we demonstrate that sparse recovery methods provide significant advantages over NN methods and the gap between the two approaches is particularly pronounced when the sampling of subspaces in the dataset is sparse. Our results suggest that OMP may be employed to reliably recover exact feature sets in a number of regimes where NN approaches fail to reveal the subspace membership of points in the ensemble.
no_new_dataset
0.9455
1503.08169
Azalia Mirhoseini
Azalia Mirhoseini, Eva L. Dyer, Ebrahim.M. Songhori, Richard G. Baraniuk, Farinaz Koushanfar
RankMap: A Platform-Aware Framework for Distributed Learning from Dense Datasets
13 pages, 10 figures
null
null
null
cs.DC cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper introduces RankMap, a platform-aware end-to-end framework for efficient execution of a broad class of iterative learning algorithms for massive and dense datasets. Our framework exploits data structure to factorize it into an ensemble of lower rank subspaces. The factorization creates sparse low-dimensional representations of the data, a property which is leveraged to devise effective mapping and scheduling of iterative learning algorithms on the distributed computing machines. We provide two APIs, one matrix-based and one graph-based, which facilitate automated adoption of the framework for performing several contemporary learning applications. To demonstrate the utility of RankMap, we solve sparse recovery and power iteration problems on various real-world datasets with up to 1.8 billion non-zeros. Our evaluations are performed on Amazon EC2 and IBM iDataPlex servers using up to 244 cores. The results demonstrate up to two orders of magnitude improvements in memory usage, execution speed, and bandwidth compared with the best reported prior work, while achieving the same level of learning accuracy.
[ { "version": "v1", "created": "Fri, 27 Mar 2015 18:02:51 GMT" }, { "version": "v2", "created": "Thu, 27 Oct 2016 14:29:44 GMT" } ]
2016-10-28T00:00:00
[ [ "Mirhoseini", "Azalia", "" ], [ "Dyer", "Eva L.", "" ], [ "Songhori", "Ebrahim. M.", "" ], [ "Baraniuk", "Richard G.", "" ], [ "Koushanfar", "Farinaz", "" ] ]
TITLE: RankMap: A Platform-Aware Framework for Distributed Learning from Dense Datasets ABSTRACT: This paper introduces RankMap, a platform-aware end-to-end framework for efficient execution of a broad class of iterative learning algorithms for massive and dense datasets. Our framework exploits data structure to factorize it into an ensemble of lower rank subspaces. The factorization creates sparse low-dimensional representations of the data, a property which is leveraged to devise effective mapping and scheduling of iterative learning algorithms on the distributed computing machines. We provide two APIs, one matrix-based and one graph-based, which facilitate automated adoption of the framework for performing several contemporary learning applications. To demonstrate the utility of RankMap, we solve sparse recovery and power iteration problems on various real-world datasets with up to 1.8 billion non-zeros. Our evaluations are performed on Amazon EC2 and IBM iDataPlex servers using up to 244 cores. The results demonstrate up to two orders of magnitude improvements in memory usage, execution speed, and bandwidth compared with the best reported prior work, while achieving the same level of learning accuracy.
no_new_dataset
0.946745
1505.00468
Aishwarya Agrawal
Aishwarya Agrawal, Jiasen Lu, Stanislaw Antol, Margaret Mitchell, C. Lawrence Zitnick, Dhruv Batra, Devi Parikh
VQA: Visual Question Answering
The first three authors contributed equally. International Conference on Computer Vision (ICCV) 2015
null
null
null
cs.CL cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose the task of free-form and open-ended Visual Question Answering (VQA). Given an image and a natural language question about the image, the task is to provide an accurate natural language answer. Mirroring real-world scenarios, such as helping the visually impaired, both the questions and answers are open-ended. Visual questions selectively target different areas of an image, including background details and underlying context. As a result, a system that succeeds at VQA typically needs a more detailed understanding of the image and complex reasoning than a system producing generic image captions. Moreover, VQA is amenable to automatic evaluation, since many open-ended answers contain only a few words or a closed set of answers that can be provided in a multiple-choice format. We provide a dataset containing ~0.25M images, ~0.76M questions, and ~10M answers (www.visualqa.org), and discuss the information it provides. Numerous baselines and methods for VQA are provided and compared with human performance. Our VQA demo is available on CloudCV (http://cloudcv.org/vqa).
[ { "version": "v1", "created": "Sun, 3 May 2015 20:07:39 GMT" }, { "version": "v2", "created": "Tue, 16 Jun 2015 16:59:52 GMT" }, { "version": "v3", "created": "Thu, 15 Oct 2015 02:47:20 GMT" }, { "version": "v4", "created": "Wed, 18 Nov 2015 16:43:33 GMT" }, { "version": "v5", "created": "Mon, 7 Mar 2016 20:55:28 GMT" }, { "version": "v6", "created": "Wed, 20 Apr 2016 03:09:33 GMT" }, { "version": "v7", "created": "Thu, 27 Oct 2016 03:50:19 GMT" } ]
2016-10-28T00:00:00
[ [ "Agrawal", "Aishwarya", "" ], [ "Lu", "Jiasen", "" ], [ "Antol", "Stanislaw", "" ], [ "Mitchell", "Margaret", "" ], [ "Zitnick", "C. Lawrence", "" ], [ "Batra", "Dhruv", "" ], [ "Parikh", "Devi", "" ] ]
TITLE: VQA: Visual Question Answering ABSTRACT: We propose the task of free-form and open-ended Visual Question Answering (VQA). Given an image and a natural language question about the image, the task is to provide an accurate natural language answer. Mirroring real-world scenarios, such as helping the visually impaired, both the questions and answers are open-ended. Visual questions selectively target different areas of an image, including background details and underlying context. As a result, a system that succeeds at VQA typically needs a more detailed understanding of the image and complex reasoning than a system producing generic image captions. Moreover, VQA is amenable to automatic evaluation, since many open-ended answers contain only a few words or a closed set of answers that can be provided in a multiple-choice format. We provide a dataset containing ~0.25M images, ~0.76M questions, and ~10M answers (www.visualqa.org), and discuss the information it provides. Numerous baselines and methods for VQA are provided and compared with human performance. Our VQA demo is available on CloudCV (http://cloudcv.org/vqa).
new_dataset
0.957636
1506.04843
Anirban Dasgupta
Anirban Dasgupta, Suvodip Chakrborty, Aritra Chaudhuri, Aurobinda Routray
Evaluation of Denoising Techniques for EOG signals based on SNR Estimation
in IEEE 2016 International Conference on Systems in Medicine and Biology (ICSMB)
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper evaluates four algorithms for denoising raw Electrooculography (EOG) data based on the Signal to Noise Ratio (SNR). The SNR is computed using the eigenvalue method. The filtering algorithms are a) Finite Impulse Response (FIR) bandpass filters, b) Stationary Wavelet Transform, c) Empirical Mode Decomposition (EMD) d) FIR Median Hybrid Filters. An EOG dataset has been prepared where the subject is asked to perform letter cancelation test on 20 subjects.
[ { "version": "v1", "created": "Tue, 16 Jun 2015 06:07:21 GMT" }, { "version": "v2", "created": "Thu, 27 Oct 2016 12:27:47 GMT" } ]
2016-10-28T00:00:00
[ [ "Dasgupta", "Anirban", "" ], [ "Chakrborty", "Suvodip", "" ], [ "Chaudhuri", "Aritra", "" ], [ "Routray", "Aurobinda", "" ] ]
TITLE: Evaluation of Denoising Techniques for EOG signals based on SNR Estimation ABSTRACT: This paper evaluates four algorithms for denoising raw Electrooculography (EOG) data based on the Signal to Noise Ratio (SNR). The SNR is computed using the eigenvalue method. The filtering algorithms are a) Finite Impulse Response (FIR) bandpass filters, b) Stationary Wavelet Transform, c) Empirical Mode Decomposition (EMD) d) FIR Median Hybrid Filters. An EOG dataset has been prepared where the subject is asked to perform letter cancelation test on 20 subjects.
new_dataset
0.948251
1607.06657
Ge Ou
Yan Wang, Ge Ou, Wei Pang, Lan Huang, George Macleod Coghill
e-Distance Weighted Support Vector Regression
null
null
null
null
cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a novel support vector regression approach called e-Distance Weighted Support Vector Regression (e-DWSVR).e-DWSVR specifically addresses two challenging issues in support vector regression: first, the process of noisy data; second, how to deal with the situation when the distribution of boundary data is different from that of the overall data. The proposed e-DWSVR optimizes the minimum margin and the mean of functional margin simultaneously to tackle these two issues. In addition, we use both dual coordinate descent (CD) and averaged stochastic gradient descent (ASGD) strategies to make e-DWSVR scalable to large scale problems. We report promising results obtained by e-DWSVR in comparison with existing methods on several benchmark datasets.
[ { "version": "v1", "created": "Thu, 21 Jul 2016 02:35:57 GMT" }, { "version": "v2", "created": "Tue, 9 Aug 2016 05:03:31 GMT" }, { "version": "v3", "created": "Wed, 31 Aug 2016 08:28:10 GMT" }, { "version": "v4", "created": "Thu, 27 Oct 2016 10:47:49 GMT" } ]
2016-10-28T00:00:00
[ [ "Wang", "Yan", "" ], [ "Ou", "Ge", "" ], [ "Pang", "Wei", "" ], [ "Huang", "Lan", "" ], [ "Coghill", "George Macleod", "" ] ]
TITLE: e-Distance Weighted Support Vector Regression ABSTRACT: We propose a novel support vector regression approach called e-Distance Weighted Support Vector Regression (e-DWSVR).e-DWSVR specifically addresses two challenging issues in support vector regression: first, the process of noisy data; second, how to deal with the situation when the distribution of boundary data is different from that of the overall data. The proposed e-DWSVR optimizes the minimum margin and the mean of functional margin simultaneously to tackle these two issues. In addition, we use both dual coordinate descent (CD) and averaged stochastic gradient descent (ASGD) strategies to make e-DWSVR scalable to large scale problems. We report promising results obtained by e-DWSVR in comparison with existing methods on several benchmark datasets.
no_new_dataset
0.949248
1610.01374
Samik Banerjee
Samik Banerjee, Sukhendu Das
Domain Adaptation with Soft-margin multiple feature-kernel learning beats Deep Learning for surveillance face recognition
This is an extended version of the paper accepted in CVPR Biometric Workshop, 2016. arXiv admin note: text overlap with arXiv:1610.00660
null
null
null
cs.CV cs.AI cs.HC cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Face recognition (FR) is the most preferred mode for biometric-based surveillance, due to its passive nature of detecting subjects, amongst all different types of biometric traits. FR under surveillance scenario does not give satisfactory performance due to low contrast, noise and poor illumination conditions on probes, as compared to the training samples. A state-of-the-art technology, Deep Learning, even fails to perform well in these scenarios. We propose a novel soft-margin based learning method for multiple feature-kernel combinations, followed by feature transformed using Domain Adaptation, which outperforms many recent state-of-the-art techniques, when tested using three real-world surveillance face datasets.
[ { "version": "v1", "created": "Wed, 5 Oct 2016 11:48:56 GMT" }, { "version": "v2", "created": "Thu, 27 Oct 2016 13:14:49 GMT" } ]
2016-10-28T00:00:00
[ [ "Banerjee", "Samik", "" ], [ "Das", "Sukhendu", "" ] ]
TITLE: Domain Adaptation with Soft-margin multiple feature-kernel learning beats Deep Learning for surveillance face recognition ABSTRACT: Face recognition (FR) is the most preferred mode for biometric-based surveillance, due to its passive nature of detecting subjects, amongst all different types of biometric traits. FR under surveillance scenario does not give satisfactory performance due to low contrast, noise and poor illumination conditions on probes, as compared to the training samples. A state-of-the-art technology, Deep Learning, even fails to perform well in these scenarios. We propose a novel soft-margin based learning method for multiple feature-kernel combinations, followed by feature transformed using Domain Adaptation, which outperforms many recent state-of-the-art techniques, when tested using three real-world surveillance face datasets.
no_new_dataset
0.94887
1610.08559
Ke Yang
Ke Yang and Julia Stoyanovich
Measuring Fairness in Ranked Outputs
5 pages, 7 figures, FATML 2016
null
null
null
cs.DB
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Ranking and scoring are ubiquitous. We consider the setting in which an institution, called a ranker, evaluates a set of individuals based on demographic, behavioral or other characteristics. The final output is a ranking that represents the relative quality of the individuals. While automatic and therefore seemingly objective, rankers can, and often do, discriminate against individuals and systematically disadvantage members of protected groups. This warrants a careful study of the fairness of a ranking scheme. In this paper we propose fairness measures for ranked outputs. We develop a data generation procedure that allows us to systematically control the degree of unfairness in the output, and study the behavior of our measures on these datasets. We then apply our proposed measures to several real datasets, and demonstrate cases of unfairness. Finally, we show preliminary results of incorporating our ranked fairness measures into an optimization framework, and show potential for improving fairness of ranked outputs while maintaining accuracy.
[ { "version": "v1", "created": "Wed, 26 Oct 2016 22:02:39 GMT" } ]
2016-10-28T00:00:00
[ [ "Yang", "Ke", "" ], [ "Stoyanovich", "Julia", "" ] ]
TITLE: Measuring Fairness in Ranked Outputs ABSTRACT: Ranking and scoring are ubiquitous. We consider the setting in which an institution, called a ranker, evaluates a set of individuals based on demographic, behavioral or other characteristics. The final output is a ranking that represents the relative quality of the individuals. While automatic and therefore seemingly objective, rankers can, and often do, discriminate against individuals and systematically disadvantage members of protected groups. This warrants a careful study of the fairness of a ranking scheme. In this paper we propose fairness measures for ranked outputs. We develop a data generation procedure that allows us to systematically control the degree of unfairness in the output, and study the behavior of our measures on these datasets. We then apply our proposed measures to several real datasets, and demonstrate cases of unfairness. Finally, we show preliminary results of incorporating our ranked fairness measures into an optimization framework, and show potential for improving fairness of ranked outputs while maintaining accuracy.
no_new_dataset
0.946892
1610.08624
PeiXin Hou
Peixin Hou, Hao Deng, Jiguang Yue, and Shuguang Liu
PCM and APCM Revisited: An Uncertainty Perspective
8 pages
null
null
null
cs.CV stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we take a new look at the possibilistic c-means (PCM) and adaptive PCM (APCM) clustering algorithms from the perspective of uncertainty. This new perspective offers us insights into the clustering process, and also provides us greater degree of flexibility. We analyze the clustering behavior of PCM-based algorithms and introduce parameters $\sigma_v$ and $\alpha$ to characterize uncertainty of estimated bandwidth and noise level of the dataset respectively. Then uncertainty (fuzziness) of membership values caused by uncertainty of the estimated bandwidth parameter is modeled by a conditional fuzzy set, which is a new formulation of the type-2 fuzzy set. Experiments show that parameters $\sigma_v$ and $\alpha$ make the clustering process more easy to control, and main features of PCM and APCM are unified in this new clustering framework (UPCM). More specifically, UPCM reduces to PCM when we set a small $\alpha$ or a large $\sigma_v$, and UPCM reduces to APCM when clusters are confined in their physical clusters and possible cluster elimination are ensured. Finally we present further researches of this paper.
[ { "version": "v1", "created": "Thu, 27 Oct 2016 05:41:23 GMT" } ]
2016-10-28T00:00:00
[ [ "Hou", "Peixin", "" ], [ "Deng", "Hao", "" ], [ "Yue", "Jiguang", "" ], [ "Liu", "Shuguang", "" ] ]
TITLE: PCM and APCM Revisited: An Uncertainty Perspective ABSTRACT: In this paper, we take a new look at the possibilistic c-means (PCM) and adaptive PCM (APCM) clustering algorithms from the perspective of uncertainty. This new perspective offers us insights into the clustering process, and also provides us greater degree of flexibility. We analyze the clustering behavior of PCM-based algorithms and introduce parameters $\sigma_v$ and $\alpha$ to characterize uncertainty of estimated bandwidth and noise level of the dataset respectively. Then uncertainty (fuzziness) of membership values caused by uncertainty of the estimated bandwidth parameter is modeled by a conditional fuzzy set, which is a new formulation of the type-2 fuzzy set. Experiments show that parameters $\sigma_v$ and $\alpha$ make the clustering process more easy to control, and main features of PCM and APCM are unified in this new clustering framework (UPCM). More specifically, UPCM reduces to PCM when we set a small $\alpha$ or a large $\sigma_v$, and UPCM reduces to APCM when clusters are confined in their physical clusters and possible cluster elimination are ensured. Finally we present further researches of this paper.
no_new_dataset
0.9455
1610.08640
Marc Schoenauer
Marti Luis (TAO, LRI), Fansi-Tchango Arsene (TRT), Navarro Laurent (TRT), Marc Schoenauer (TAO, LRI)
Anomaly Detection with the Voronoi Diagram Evolutionary Algorithm
null
Parallel Problem Solving from Nature -- PPSN XIV, Sep 2016, Edinburgh, France. Springer Verlag, 9921, pp.697-706, 2016, LNCS
null
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper presents the Voronoi diagram-based evolutionary algorithm (VorEAl). VorEAl partitions input space in abnormal/normal subsets using Voronoi diagrams. Diagrams are evolved using a multi-objective bio-inspired approach in order to conjointly optimize classification metrics while also being able to represent areas of the data space that are not present in the training dataset. As part of the paper VorEAl is experimentally validated and contrasted with similar approaches.
[ { "version": "v1", "created": "Thu, 27 Oct 2016 07:05:54 GMT" } ]
2016-10-28T00:00:00
[ [ "Luis", "Marti", "", "TAO, LRI" ], [ "Arsene", "Fansi-Tchango", "", "TRT" ], [ "Laurent", "Navarro", "", "TRT" ], [ "Schoenauer", "Marc", "", "TAO, LRI" ] ]
TITLE: Anomaly Detection with the Voronoi Diagram Evolutionary Algorithm ABSTRACT: This paper presents the Voronoi diagram-based evolutionary algorithm (VorEAl). VorEAl partitions input space in abnormal/normal subsets using Voronoi diagrams. Diagrams are evolved using a multi-objective bio-inspired approach in order to conjointly optimize classification metrics while also being able to represent areas of the data space that are not present in the training dataset. As part of the paper VorEAl is experimentally validated and contrasted with similar approaches.
no_new_dataset
0.948251
1610.08686
Mauro Coletto
Mauro Coletto, Claudio Lucchese, Salvatore Orlando, Raffaele Perego
Polarized User and Topic Tracking in Twitter
SIGIR 16
null
null
null
cs.SI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Digital traces of conversations in micro-blogging platforms and OSNs provide information about user opinion with a high degree of resolution. These information sources can be exploited to under- stand and monitor collective behaviors. In this work, we focus on polarization classes, i.e., those topics that require the user to side exclusively with one position. The proposed method provides an iterative classification of users and keywords: first, polarized users are identified, then polarized keywords are discovered by monitoring the activities of previously classified users. This method thus allows tracking users and topics over time. We report several experiments conducted on two Twitter datasets during political election time-frames. We measure the user classification accuracy on a golden set of users, and analyze the relevance of the extracted keywords for the ongoing political discussion.
[ { "version": "v1", "created": "Thu, 27 Oct 2016 10:03:31 GMT" } ]
2016-10-28T00:00:00
[ [ "Coletto", "Mauro", "" ], [ "Lucchese", "Claudio", "" ], [ "Orlando", "Salvatore", "" ], [ "Perego", "Raffaele", "" ] ]
TITLE: Polarized User and Topic Tracking in Twitter ABSTRACT: Digital traces of conversations in micro-blogging platforms and OSNs provide information about user opinion with a high degree of resolution. These information sources can be exploited to under- stand and monitor collective behaviors. In this work, we focus on polarization classes, i.e., those topics that require the user to side exclusively with one position. The proposed method provides an iterative classification of users and keywords: first, polarized users are identified, then polarized keywords are discovered by monitoring the activities of previously classified users. This method thus allows tracking users and topics over time. We report several experiments conducted on two Twitter datasets during political election time-frames. We measure the user classification accuracy on a golden set of users, and analyze the relevance of the extracted keywords for the ongoing political discussion.
no_new_dataset
0.951006
1610.08739
Andre Droschinsky
Andre Droschinsky and Nils Kriege and Petra Mutzel
Finding Largest Common Substructures of Molecules in Quadratic Time
null
null
null
null
cs.DS cs.CC
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Finding the common structural features of two molecules is a fundamental task in cheminformatics. Most drugs are small molecules, which can naturally be interpreted as graphs. Hence, the task is formalized as maximum common subgraph problem. Albeit the vast majority of molecules yields outerplanar graphs this problem remains NP-hard. We consider a variation of the problem of high practical relevance, where the rings of molecules must not be broken, i.e., the block and bridge structure of the input graphs must be retained by the common subgraph. We present an algorithm for finding a maximum common connected induced subgraph of two given outerplanar graphs subject to this constraint. Our approach runs in time $\mathcal{O}(\Delta n^2)$ in outerplanar graphs on $n$ vertices with maximum degree $\Delta$. This leads to a quadratic time complexity in molecular graphs, which have bounded degree. The experimental comparison on synthetic and real-world datasets shows that our approach is highly efficient in practice and outperforms comparable state-of-the-art algorithms.
[ { "version": "v1", "created": "Thu, 27 Oct 2016 12:16:01 GMT" } ]
2016-10-28T00:00:00
[ [ "Droschinsky", "Andre", "" ], [ "Kriege", "Nils", "" ], [ "Mutzel", "Petra", "" ] ]
TITLE: Finding Largest Common Substructures of Molecules in Quadratic Time ABSTRACT: Finding the common structural features of two molecules is a fundamental task in cheminformatics. Most drugs are small molecules, which can naturally be interpreted as graphs. Hence, the task is formalized as maximum common subgraph problem. Albeit the vast majority of molecules yields outerplanar graphs this problem remains NP-hard. We consider a variation of the problem of high practical relevance, where the rings of molecules must not be broken, i.e., the block and bridge structure of the input graphs must be retained by the common subgraph. We present an algorithm for finding a maximum common connected induced subgraph of two given outerplanar graphs subject to this constraint. Our approach runs in time $\mathcal{O}(\Delta n^2)$ in outerplanar graphs on $n$ vertices with maximum degree $\Delta$. This leads to a quadratic time complexity in molecular graphs, which have bounded degree. The experimental comparison on synthetic and real-world datasets shows that our approach is highly efficient in practice and outperforms comparable state-of-the-art algorithms.
no_new_dataset
0.945045
1610.08854
Manish Sahu
Manish Sahu, Anirban Mukhopadhyay, Angelika Szengel and Stefan Zachow
Tool and Phase recognition using contextual CNN features
MICCAI M2CAI 2016 Surgical tool & phase detection challenge report
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A transfer learning method for generating features suitable for surgical tools and phase recognition from the ImageNet classification features [1] is proposed here. In addition, methods are developed for generating contextual features and combining them with time series analysis for final classification using multi-class random forest. The proposed pipeline is tested over the training and testing datasets of M2CAI16 challenges: tool and phase detection. Encouraging results are obtained by leave-one-out cross validation evaluation on the training dataset.
[ { "version": "v1", "created": "Thu, 27 Oct 2016 15:54:41 GMT" } ]
2016-10-28T00:00:00
[ [ "Sahu", "Manish", "" ], [ "Mukhopadhyay", "Anirban", "" ], [ "Szengel", "Angelika", "" ], [ "Zachow", "Stefan", "" ] ]
TITLE: Tool and Phase recognition using contextual CNN features ABSTRACT: A transfer learning method for generating features suitable for surgical tools and phase recognition from the ImageNet classification features [1] is proposed here. In addition, methods are developed for generating contextual features and combining them with time series analysis for final classification using multi-class random forest. The proposed pipeline is tested over the training and testing datasets of M2CAI16 challenges: tool and phase detection. Encouraging results are obtained by leave-one-out cross validation evaluation on the training dataset.
no_new_dataset
0.945147
1610.08871
Nicholas Westlake
Nicholas Westlake, Hongping Cai and Peter Hall
Detecting People in Artwork with CNNs
14 pages, plus 3 pages of references; 7 figures in ECCV 2016 Workshops
null
10.1007/978-3-319-46604-0_57
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
CNNs have massively improved performance in object detection in photographs. However research into object detection in artwork remains limited. We show state-of-the-art performance on a challenging dataset, People-Art, which contains people from photos, cartoons and 41 different artwork movements. We achieve this high performance by fine-tuning a CNN for this task, thus also demonstrating that training CNNs on photos results in overfitting for photos: only the first three or four layers transfer from photos to artwork. Although the CNN's performance is the highest yet, it remains less than 60\% AP, suggesting further work is needed for the cross-depiction problem. The final publication is available at Springer via http://dx.doi.org/10.1007/978-3-319-46604-0_57
[ { "version": "v1", "created": "Thu, 27 Oct 2016 16:30:15 GMT" } ]
2016-10-28T00:00:00
[ [ "Westlake", "Nicholas", "" ], [ "Cai", "Hongping", "" ], [ "Hall", "Peter", "" ] ]
TITLE: Detecting People in Artwork with CNNs ABSTRACT: CNNs have massively improved performance in object detection in photographs. However research into object detection in artwork remains limited. We show state-of-the-art performance on a challenging dataset, People-Art, which contains people from photos, cartoons and 41 different artwork movements. We achieve this high performance by fine-tuning a CNN for this task, thus also demonstrating that training CNNs on photos results in overfitting for photos: only the first three or four layers transfer from photos to artwork. Although the CNN's performance is the highest yet, it remains less than 60\% AP, suggesting further work is needed for the cross-depiction problem. The final publication is available at Springer via http://dx.doi.org/10.1007/978-3-319-46604-0_57
no_new_dataset
0.933491
1610.08904
Chen Huang
Chen Huang, Chen Change Loy, Xiaoou Tang
Local Similarity-Aware Deep Feature Embedding
9 pages, 4 figures, 2 tables. Accepted to NIPS 2016
null
null
null
cs.CV cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Existing deep embedding methods in vision tasks are capable of learning a compact Euclidean space from images, where Euclidean distances correspond to a similarity metric. To make learning more effective and efficient, hard sample mining is usually employed, with samples identified through computing the Euclidean feature distance. However, the global Euclidean distance cannot faithfully characterize the true feature similarity in a complex visual feature space, where the intraclass distance in a high-density region may be larger than the interclass distance in low-density regions. In this paper, we introduce a Position-Dependent Deep Metric (PDDM) unit, which is capable of learning a similarity metric adaptive to local feature structure. The metric can be used to select genuinely hard samples in a local neighborhood to guide the deep embedding learning in an online and robust manner. The new layer is appealing in that it is pluggable to any convolutional networks and is trained end-to-end. Our local similarity-aware feature embedding not only demonstrates faster convergence and boosted performance on two complex image retrieval datasets, its large margin nature also leads to superior generalization results under the large and open set scenarios of transfer learning and zero-shot learning on ImageNet 2010 and ImageNet-10K datasets.
[ { "version": "v1", "created": "Thu, 27 Oct 2016 17:51:18 GMT" } ]
2016-10-28T00:00:00
[ [ "Huang", "Chen", "" ], [ "Loy", "Chen Change", "" ], [ "Tang", "Xiaoou", "" ] ]
TITLE: Local Similarity-Aware Deep Feature Embedding ABSTRACT: Existing deep embedding methods in vision tasks are capable of learning a compact Euclidean space from images, where Euclidean distances correspond to a similarity metric. To make learning more effective and efficient, hard sample mining is usually employed, with samples identified through computing the Euclidean feature distance. However, the global Euclidean distance cannot faithfully characterize the true feature similarity in a complex visual feature space, where the intraclass distance in a high-density region may be larger than the interclass distance in low-density regions. In this paper, we introduce a Position-Dependent Deep Metric (PDDM) unit, which is capable of learning a similarity metric adaptive to local feature structure. The metric can be used to select genuinely hard samples in a local neighborhood to guide the deep embedding learning in an online and robust manner. The new layer is appealing in that it is pluggable to any convolutional networks and is trained end-to-end. Our local similarity-aware feature embedding not only demonstrates faster convergence and boosted performance on two complex image retrieval datasets, its large margin nature also leads to superior generalization results under the large and open set scenarios of transfer learning and zero-shot learning on ImageNet 2010 and ImageNet-10K datasets.
no_new_dataset
0.948298
1608.05995
Ming Lin
Ming Lin and Jieping Ye
A Non-convex One-Pass Framework for Generalized Factorization Machine and Rank-One Matrix Sensing
accepted by NIPS 2016
null
null
null
stat.ML cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We develop an efficient alternating framework for learning a generalized version of Factorization Machine (gFM) on steaming data with provable guarantees. When the instances are sampled from $d$ dimensional random Gaussian vectors and the target second order coefficient matrix in gFM is of rank $k$, our algorithm converges linearly, achieves $O(\epsilon)$ recovery error after retrieving $O(k^{3}d\log(1/\epsilon))$ training instances, consumes $O(kd)$ memory in one-pass of dataset and only requires matrix-vector product operations in each iteration. The key ingredient of our framework is a construction of an estimation sequence endowed with a so-called Conditionally Independent RIP condition (CI-RIP). As special cases of gFM, our framework can be applied to symmetric or asymmetric rank-one matrix sensing problems, such as inductive matrix completion and phase retrieval.
[ { "version": "v1", "created": "Sun, 21 Aug 2016 20:28:29 GMT" }, { "version": "v2", "created": "Fri, 9 Sep 2016 17:54:50 GMT" }, { "version": "v3", "created": "Mon, 12 Sep 2016 21:43:05 GMT" }, { "version": "v4", "created": "Wed, 14 Sep 2016 02:24:22 GMT" }, { "version": "v5", "created": "Tue, 25 Oct 2016 21:23:23 GMT" } ]
2016-10-27T00:00:00
[ [ "Lin", "Ming", "" ], [ "Ye", "Jieping", "" ] ]
TITLE: A Non-convex One-Pass Framework for Generalized Factorization Machine and Rank-One Matrix Sensing ABSTRACT: We develop an efficient alternating framework for learning a generalized version of Factorization Machine (gFM) on steaming data with provable guarantees. When the instances are sampled from $d$ dimensional random Gaussian vectors and the target second order coefficient matrix in gFM is of rank $k$, our algorithm converges linearly, achieves $O(\epsilon)$ recovery error after retrieving $O(k^{3}d\log(1/\epsilon))$ training instances, consumes $O(kd)$ memory in one-pass of dataset and only requires matrix-vector product operations in each iteration. The key ingredient of our framework is a construction of an estimation sequence endowed with a so-called Conditionally Independent RIP condition (CI-RIP). As special cases of gFM, our framework can be applied to symmetric or asymmetric rank-one matrix sensing problems, such as inductive matrix completion and phase retrieval.
no_new_dataset
0.942823
1610.06656
Shanshan Wu
Shanshan Wu, Srinadh Bhojanapalli, Sujay Sanghavi, Alexandros G. Dimakis
Single Pass PCA of Matrix Products
24 pages, 4 figures, NIPS 2016
null
null
null
stat.ML cs.DS cs.IT cs.LG math.IT
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we present a new algorithm for computing a low rank approximation of the product $A^TB$ by taking only a single pass of the two matrices $A$ and $B$. The straightforward way to do this is to (a) first sketch $A$ and $B$ individually, and then (b) find the top components using PCA on the sketch. Our algorithm in contrast retains additional summary information about $A,B$ (e.g. row and column norms etc.) and uses this additional information to obtain an improved approximation from the sketches. Our main analytical result establishes a comparable spectral norm guarantee to existing two-pass methods; in addition we also provide results from an Apache Spark implementation that shows better computational and statistical performance on real-world and synthetic evaluation datasets.
[ { "version": "v1", "created": "Fri, 21 Oct 2016 02:45:46 GMT" }, { "version": "v2", "created": "Wed, 26 Oct 2016 13:58:24 GMT" } ]
2016-10-27T00:00:00
[ [ "Wu", "Shanshan", "" ], [ "Bhojanapalli", "Srinadh", "" ], [ "Sanghavi", "Sujay", "" ], [ "Dimakis", "Alexandros G.", "" ] ]
TITLE: Single Pass PCA of Matrix Products ABSTRACT: In this paper we present a new algorithm for computing a low rank approximation of the product $A^TB$ by taking only a single pass of the two matrices $A$ and $B$. The straightforward way to do this is to (a) first sketch $A$ and $B$ individually, and then (b) find the top components using PCA on the sketch. Our algorithm in contrast retains additional summary information about $A,B$ (e.g. row and column norms etc.) and uses this additional information to obtain an improved approximation from the sketches. Our main analytical result establishes a comparable spectral norm guarantee to existing two-pass methods; in addition we also provide results from an Apache Spark implementation that shows better computational and statistical performance on real-world and synthetic evaluation datasets.
no_new_dataset
0.944074
1610.07667
Nir Rosenfeld
Nir Rosenfeld, Yishay Mansour, Elad Yom-Tov
Predicting Counterfactuals from Large Historical Data and Small Randomized Trials
null
null
null
null
cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
When a new treatment is considered for use, whether a pharmaceutical drug or a search engine ranking algorithm, a typical question that arises is, will its performance exceed that of the current treatment? The conventional way to answer this counterfactual question is to estimate the effect of the new treatment in comparison to that of the conventional treatment by running a controlled, randomized experiment. While this approach theoretically ensures an unbiased estimator, it suffers from several drawbacks, including the difficulty in finding representative experimental populations as well as the cost of running such trials. Moreover, such trials neglect the huge quantities of available control-condition data which are often completely ignored. In this paper we propose a discriminative framework for estimating the performance of a new treatment given a large dataset of the control condition and data from a small (and possibly unrepresentative) randomized trial comparing new and old treatments. Our objective, which requires minimal assumptions on the treatments, models the relation between the outcomes of the different conditions. This allows us to not only estimate mean effects but also to generate individual predictions for examples outside the randomized sample. We demonstrate the utility of our approach through experiments in three areas: Search engine operation, treatments to diabetes patients, and market value estimation for houses. Our results demonstrate that our approach can reduce the number and size of the currently performed randomized controlled experiments, thus saving significant time, money and effort on the part of practitioners.
[ { "version": "v1", "created": "Mon, 24 Oct 2016 22:12:52 GMT" }, { "version": "v2", "created": "Wed, 26 Oct 2016 06:11:07 GMT" } ]
2016-10-27T00:00:00
[ [ "Rosenfeld", "Nir", "" ], [ "Mansour", "Yishay", "" ], [ "Yom-Tov", "Elad", "" ] ]
TITLE: Predicting Counterfactuals from Large Historical Data and Small Randomized Trials ABSTRACT: When a new treatment is considered for use, whether a pharmaceutical drug or a search engine ranking algorithm, a typical question that arises is, will its performance exceed that of the current treatment? The conventional way to answer this counterfactual question is to estimate the effect of the new treatment in comparison to that of the conventional treatment by running a controlled, randomized experiment. While this approach theoretically ensures an unbiased estimator, it suffers from several drawbacks, including the difficulty in finding representative experimental populations as well as the cost of running such trials. Moreover, such trials neglect the huge quantities of available control-condition data which are often completely ignored. In this paper we propose a discriminative framework for estimating the performance of a new treatment given a large dataset of the control condition and data from a small (and possibly unrepresentative) randomized trial comparing new and old treatments. Our objective, which requires minimal assumptions on the treatments, models the relation between the outcomes of the different conditions. This allows us to not only estimate mean effects but also to generate individual predictions for examples outside the randomized sample. We demonstrate the utility of our approach through experiments in three areas: Search engine operation, treatments to diabetes patients, and market value estimation for houses. Our results demonstrate that our approach can reduce the number and size of the currently performed randomized controlled experiments, thus saving significant time, money and effort on the part of practitioners.
no_new_dataset
0.94474
1610.08077
James Johndrow
Kristian Lum and James Johndrow
A statistical framework for fair predictive algorithms
null
null
null
null
stat.ML cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Predictive modeling is increasingly being employed to assist human decision-makers. One purported advantage of replacing human judgment with computer models in high stakes settings-- such as sentencing, hiring, policing, college admissions, and parole decisions-- is the perceived "neutrality" of computers. It is argued that because computer models do not hold personal prejudice, the predictions they produce will be equally free from prejudice. There is growing recognition that employing algorithms does not remove the potential for bias, and can even amplify it, since training data were inevitably generated by a process that is itself biased. In this paper, we provide a probabilistic definition of algorithmic bias. We propose a method to remove bias from predictive models by removing all information regarding protected variables from the permitted training data. Unlike previous work in this area, our framework is general enough to accommodate arbitrary data types, e.g. binary, continuous, etc. Motivated by models currently in use in the criminal justice system that inform decisions on pre-trial release and paroling, we apply our proposed method to a dataset on the criminal histories of individuals at the time of sentencing to produce "race-neutral" predictions of re-arrest. In the process, we demonstrate that the most common approach to creating "race-neutral" models-- omitting race as a covariate-- still results in racially disparate predictions. We then demonstrate that the application of our proposed method to these data removes racial disparities from predictions with minimal impact on predictive accuracy.
[ { "version": "v1", "created": "Tue, 25 Oct 2016 20:18:24 GMT" } ]
2016-10-27T00:00:00
[ [ "Lum", "Kristian", "" ], [ "Johndrow", "James", "" ] ]
TITLE: A statistical framework for fair predictive algorithms ABSTRACT: Predictive modeling is increasingly being employed to assist human decision-makers. One purported advantage of replacing human judgment with computer models in high stakes settings-- such as sentencing, hiring, policing, college admissions, and parole decisions-- is the perceived "neutrality" of computers. It is argued that because computer models do not hold personal prejudice, the predictions they produce will be equally free from prejudice. There is growing recognition that employing algorithms does not remove the potential for bias, and can even amplify it, since training data were inevitably generated by a process that is itself biased. In this paper, we provide a probabilistic definition of algorithmic bias. We propose a method to remove bias from predictive models by removing all information regarding protected variables from the permitted training data. Unlike previous work in this area, our framework is general enough to accommodate arbitrary data types, e.g. binary, continuous, etc. Motivated by models currently in use in the criminal justice system that inform decisions on pre-trial release and paroling, we apply our proposed method to a dataset on the criminal histories of individuals at the time of sentencing to produce "race-neutral" predictions of re-arrest. In the process, we demonstrate that the most common approach to creating "race-neutral" models-- omitting race as a covariate-- still results in racially disparate predictions. We then demonstrate that the application of our proposed method to these data removes racial disparities from predictions with minimal impact on predictive accuracy.
no_new_dataset
0.943138
1610.08095
Mengting Wan
Mengting Wan, Julian McAuley
Modeling Ambiguity, Subjectivity, and Diverging Viewpoints in Opinion Question Answering Systems
10 pages, accepted by ICDM'2016
null
null
null
cs.IR cs.CL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Product review websites provide an incredible lens into the wide variety of opinions and experiences of different people, and play a critical role in helping users discover products that match their personal needs and preferences. To help address questions that can't easily be answered by reading others' reviews, some review websites also allow users to pose questions to the community via a question-answering (QA) system. As one would expect, just as opinions diverge among different reviewers, answers to such questions may also be subjective, opinionated, and divergent. This means that answering such questions automatically is quite different from traditional QA tasks, where it is assumed that a single `correct' answer is available. While recent work introduced the idea of question-answering using product reviews, it did not account for two aspects that we consider in this paper: (1) Questions have multiple, often divergent, answers, and this full spectrum of answers should somehow be used to train the system; and (2) What makes a `good' answer depends on the asker and the answerer, and these factors should be incorporated in order for the system to be more personalized. Here we build a new QA dataset with 800 thousand questions---and over 3.1 million answers---and show that explicitly accounting for personalization and ambiguity leads both to quantitatively better answers, but also a more nuanced view of the range of supporting, but subjective, opinions.
[ { "version": "v1", "created": "Tue, 25 Oct 2016 21:08:15 GMT" } ]
2016-10-27T00:00:00
[ [ "Wan", "Mengting", "" ], [ "McAuley", "Julian", "" ] ]
TITLE: Modeling Ambiguity, Subjectivity, and Diverging Viewpoints in Opinion Question Answering Systems ABSTRACT: Product review websites provide an incredible lens into the wide variety of opinions and experiences of different people, and play a critical role in helping users discover products that match their personal needs and preferences. To help address questions that can't easily be answered by reading others' reviews, some review websites also allow users to pose questions to the community via a question-answering (QA) system. As one would expect, just as opinions diverge among different reviewers, answers to such questions may also be subjective, opinionated, and divergent. This means that answering such questions automatically is quite different from traditional QA tasks, where it is assumed that a single `correct' answer is available. While recent work introduced the idea of question-answering using product reviews, it did not account for two aspects that we consider in this paper: (1) Questions have multiple, often divergent, answers, and this full spectrum of answers should somehow be used to train the system; and (2) What makes a `good' answer depends on the asker and the answerer, and these factors should be incorporated in order for the system to be more personalized. Here we build a new QA dataset with 800 thousand questions---and over 3.1 million answers---and show that explicitly accounting for personalization and ambiguity leads both to quantitatively better answers, but also a more nuanced view of the range of supporting, but subjective, opinions.
new_dataset
0.961207
1610.08120
Suchet Bargoti
Suchet Bargoti, James Underwood
Image Segmentation for Fruit Detection and Yield Estimation in Apple Orchards
This paper is the initial version of the manuscript submitted to The Journal of Field Robotics in May 2016. Following reviews and revisions, the paper has been accepted for publication. The reviewed version includes extended comparison between the different classification frameworks and a more in-depth literature review
null
null
null
cs.RO cs.CV cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Ground vehicles equipped with monocular vision systems are a valuable source of high resolution image data for precision agriculture applications in orchards. This paper presents an image processing framework for fruit detection and counting using orchard image data. A general purpose image segmentation approach is used, including two feature learning algorithms; multi-scale Multi-Layered Perceptrons (MLP) and Convolutional Neural Networks (CNN). These networks were extended by including contextual information about how the image data was captured (metadata), which correlates with some of the appearance variations and/or class distributions observed in the data. The pixel-wise fruit segmentation output is processed using the Watershed Segmentation (WS) and Circular Hough Transform (CHT) algorithms to detect and count individual fruits. Experiments were conducted in a commercial apple orchard near Melbourne, Australia. The results show an improvement in fruit segmentation performance with the inclusion of metadata on the previously benchmarked MLP network. We extend this work with CNNs, bringing agrovision closer to the state-of-the-art in computer vision, where although metadata had negligible influence, the best pixel-wise F1-score of $0.791$ was achieved. The WS algorithm produced the best apple detection and counting results, with a detection F1-score of $0.858$. As a final step, image fruit counts were accumulated over multiple rows at the orchard and compared against the post-harvest fruit counts that were obtained from a grading and counting machine. The count estimates using CNN and WS resulted in the best performance for this dataset, with a squared correlation coefficient of $r^2=0.826$.
[ { "version": "v1", "created": "Tue, 25 Oct 2016 23:38:02 GMT" } ]
2016-10-27T00:00:00
[ [ "Bargoti", "Suchet", "" ], [ "Underwood", "James", "" ] ]
TITLE: Image Segmentation for Fruit Detection and Yield Estimation in Apple Orchards ABSTRACT: Ground vehicles equipped with monocular vision systems are a valuable source of high resolution image data for precision agriculture applications in orchards. This paper presents an image processing framework for fruit detection and counting using orchard image data. A general purpose image segmentation approach is used, including two feature learning algorithms; multi-scale Multi-Layered Perceptrons (MLP) and Convolutional Neural Networks (CNN). These networks were extended by including contextual information about how the image data was captured (metadata), which correlates with some of the appearance variations and/or class distributions observed in the data. The pixel-wise fruit segmentation output is processed using the Watershed Segmentation (WS) and Circular Hough Transform (CHT) algorithms to detect and count individual fruits. Experiments were conducted in a commercial apple orchard near Melbourne, Australia. The results show an improvement in fruit segmentation performance with the inclusion of metadata on the previously benchmarked MLP network. We extend this work with CNNs, bringing agrovision closer to the state-of-the-art in computer vision, where although metadata had negligible influence, the best pixel-wise F1-score of $0.791$ was achieved. The WS algorithm produced the best apple detection and counting results, with a detection F1-score of $0.858$. As a final step, image fruit counts were accumulated over multiple rows at the orchard and compared against the post-harvest fruit counts that were obtained from a grading and counting machine. The count estimates using CNN and WS resulted in the best performance for this dataset, with a squared correlation coefficient of $r^2=0.826$.
no_new_dataset
0.954478
1610.08133
Elaheh Raisi
Hamid Abrishami Moghaddam and Elaheh Raisi
Incremental Nonparametric Weighted Feature Extraction for OnlineSubspace Pattern Classification
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, a new online method based on nonparametric weighted feature extraction (NWFE) is proposed. NWFE was introduced to enjoy optimum characteristics of linear discriminant analysis (LDA) and nonparametric discriminant analysis (NDA) while rectifying their drawbacks. It emphasizes the points near decision boundary by putting greater weights on them and deemphasizes other points. Incremental nonparametric weighted feature extraction (INWFE) is the online version of NWFE. INWFE has advantages of NWFE method such as extracting more than L-1 features in contrast to LDA. It is independent of the class distribution and performs well in complex distributed data. The effects of outliers are reduced due to the nature of its nonparametric scatter matrix. Furthermore, it is possible to add new samples asynchronously, i.e. whenever a new sample becomes available at any given time, it can be added to the algorithm. This is useful for many real world applications since all data cannot be available in advance. This method is implemented on Gaussian and non-Gaussian multidimensional data, a number of UCI datasets and Indian Pine dataset. Results are compared with NWFE in terms of classification accuracy and execution time. For nearest neighbour classifier it shows that this technique converges to NWFE at the end of learning process. In addition, the computational complexity is reduced in comparison with NWFE in terms of execution time.
[ { "version": "v1", "created": "Wed, 26 Oct 2016 01:02:01 GMT" } ]
2016-10-27T00:00:00
[ [ "Moghaddam", "Hamid Abrishami", "" ], [ "Raisi", "Elaheh", "" ] ]
TITLE: Incremental Nonparametric Weighted Feature Extraction for OnlineSubspace Pattern Classification ABSTRACT: In this paper, a new online method based on nonparametric weighted feature extraction (NWFE) is proposed. NWFE was introduced to enjoy optimum characteristics of linear discriminant analysis (LDA) and nonparametric discriminant analysis (NDA) while rectifying their drawbacks. It emphasizes the points near decision boundary by putting greater weights on them and deemphasizes other points. Incremental nonparametric weighted feature extraction (INWFE) is the online version of NWFE. INWFE has advantages of NWFE method such as extracting more than L-1 features in contrast to LDA. It is independent of the class distribution and performs well in complex distributed data. The effects of outliers are reduced due to the nature of its nonparametric scatter matrix. Furthermore, it is possible to add new samples asynchronously, i.e. whenever a new sample becomes available at any given time, it can be added to the algorithm. This is useful for many real world applications since all data cannot be available in advance. This method is implemented on Gaussian and non-Gaussian multidimensional data, a number of UCI datasets and Indian Pine dataset. Results are compared with NWFE in terms of classification accuracy and execution time. For nearest neighbour classifier it shows that this technique converges to NWFE at the end of learning process. In addition, the computational complexity is reduced in comparison with NWFE in terms of execution time.
no_new_dataset
0.943034
1610.08462
Qian Chen
Qian Chen, Xiaodan Zhu, Zhenhua Ling, Si Wei, Hui Jiang
Distraction-Based Neural Networks for Document Summarization
Published in IJCAI-2016: the 25th International Joint Conference on Artificial Intelligence
IJCAI, 2016
null
null
cs.CL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Distributed representation learned with neural networks has recently shown to be effective in modeling natural languages at fine granularities such as words, phrases, and even sentences. Whether and how such an approach can be extended to help model larger spans of text, e.g., documents, is intriguing, and further investigation would still be desirable. This paper aims to enhance neural network models for such a purpose. A typical problem of document-level modeling is automatic summarization, which aims to model documents in order to generate summaries. In this paper, we propose neural models to train computers not just to pay attention to specific regions and content of input documents with attention models, but also distract them to traverse between different content of a document so as to better grasp the overall meaning for summarization. Without engineering any features, we train the models on two large datasets. The models achieve the state-of-the-art performance, and they significantly benefit from the distraction modeling, particularly when input documents are long.
[ { "version": "v1", "created": "Wed, 26 Oct 2016 18:57:00 GMT" } ]
2016-10-27T00:00:00
[ [ "Chen", "Qian", "" ], [ "Zhu", "Xiaodan", "" ], [ "Ling", "Zhenhua", "" ], [ "Wei", "Si", "" ], [ "Jiang", "Hui", "" ] ]
TITLE: Distraction-Based Neural Networks for Document Summarization ABSTRACT: Distributed representation learned with neural networks has recently shown to be effective in modeling natural languages at fine granularities such as words, phrases, and even sentences. Whether and how such an approach can be extended to help model larger spans of text, e.g., documents, is intriguing, and further investigation would still be desirable. This paper aims to enhance neural network models for such a purpose. A typical problem of document-level modeling is automatic summarization, which aims to model documents in order to generate summaries. In this paper, we propose neural models to train computers not just to pay attention to specific regions and content of input documents with attention models, but also distract them to traverse between different content of a document so as to better grasp the overall meaning for summarization. Without engineering any features, we train the models on two large datasets. The models achieve the state-of-the-art performance, and they significantly benefit from the distraction modeling, particularly when input documents are long.
no_new_dataset
0.943919
1511.04664
Mohammad Abu Alsheikh
Mohammad Abu Alsheikh, Ahmed Selim, Dusit Niyato, Linda Doyle, Shaowei Lin, Hwee-Pink Tan
Deep Activity Recognition Models with Triaxial Accelerometers
null
null
null
null
cs.LG cs.HC cs.NE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Despite the widespread installation of accelerometers in almost all mobile phones and wearable devices, activity recognition using accelerometers is still immature due to the poor recognition accuracy of existing recognition methods and the scarcity of labeled training data. We consider the problem of human activity recognition using triaxial accelerometers and deep learning paradigms. This paper shows that deep activity recognition models (a) provide better recognition accuracy of human activities, (b) avoid the expensive design of handcrafted features in existing systems, and (c) utilize the massive unlabeled acceleration samples for unsupervised feature extraction. Moreover, a hybrid approach of deep learning and hidden Markov models (DL-HMM) is presented for sequential activity recognition. This hybrid approach integrates the hierarchical representations of deep activity recognition models with the stochastic modeling of temporal sequences in the hidden Markov models. We show substantial recognition improvement on real world datasets over state-of-the-art methods of human activity recognition using triaxial accelerometers.
[ { "version": "v1", "created": "Sun, 15 Nov 2015 06:23:40 GMT" }, { "version": "v2", "created": "Tue, 25 Oct 2016 07:39:29 GMT" } ]
2016-10-26T00:00:00
[ [ "Alsheikh", "Mohammad Abu", "" ], [ "Selim", "Ahmed", "" ], [ "Niyato", "Dusit", "" ], [ "Doyle", "Linda", "" ], [ "Lin", "Shaowei", "" ], [ "Tan", "Hwee-Pink", "" ] ]
TITLE: Deep Activity Recognition Models with Triaxial Accelerometers ABSTRACT: Despite the widespread installation of accelerometers in almost all mobile phones and wearable devices, activity recognition using accelerometers is still immature due to the poor recognition accuracy of existing recognition methods and the scarcity of labeled training data. We consider the problem of human activity recognition using triaxial accelerometers and deep learning paradigms. This paper shows that deep activity recognition models (a) provide better recognition accuracy of human activities, (b) avoid the expensive design of handcrafted features in existing systems, and (c) utilize the massive unlabeled acceleration samples for unsupervised feature extraction. Moreover, a hybrid approach of deep learning and hidden Markov models (DL-HMM) is presented for sequential activity recognition. This hybrid approach integrates the hierarchical representations of deep activity recognition models with the stochastic modeling of temporal sequences in the hidden Markov models. We show substantial recognition improvement on real world datasets over state-of-the-art methods of human activity recognition using triaxial accelerometers.
no_new_dataset
0.948489
1511.08250
Bernardino Romera-Paredes
Bernardino Romera-Paredes, Philip H. S. Torr
Recurrent Instance Segmentation
14 pages (main paper). 24 pages including references and appendix
ECCV 2016. 14th European Conference on Computer Vision
null
null
cs.CV cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Instance segmentation is the problem of detecting and delineating each distinct object of interest appearing in an image. Current instance segmentation approaches consist of ensembles of modules that are trained independently of each other, thus missing opportunities for joint learning. Here we propose a new instance segmentation paradigm consisting in an end-to-end method that learns how to segment instances sequentially. The model is based on a recurrent neural network that sequentially finds objects and their segmentations one at a time. This net is provided with a spatial memory that keeps track of what pixels have been explained and allows occlusion handling. In order to train the model we designed a principled loss function that accurately represents the properties of the instance segmentation problem. In the experiments carried out, we found that our method outperforms recent approaches on multiple person segmentation, and all state of the art approaches on the Plant Phenotyping dataset for leaf counting.
[ { "version": "v1", "created": "Wed, 25 Nov 2015 23:28:14 GMT" }, { "version": "v2", "created": "Tue, 5 Apr 2016 22:45:04 GMT" }, { "version": "v3", "created": "Mon, 24 Oct 2016 23:57:19 GMT" } ]
2016-10-26T00:00:00
[ [ "Romera-Paredes", "Bernardino", "" ], [ "Torr", "Philip H. S.", "" ] ]
TITLE: Recurrent Instance Segmentation ABSTRACT: Instance segmentation is the problem of detecting and delineating each distinct object of interest appearing in an image. Current instance segmentation approaches consist of ensembles of modules that are trained independently of each other, thus missing opportunities for joint learning. Here we propose a new instance segmentation paradigm consisting in an end-to-end method that learns how to segment instances sequentially. The model is based on a recurrent neural network that sequentially finds objects and their segmentations one at a time. This net is provided with a spatial memory that keeps track of what pixels have been explained and allows occlusion handling. In order to train the model we designed a principled loss function that accurately represents the properties of the instance segmentation problem. In the experiments carried out, we found that our method outperforms recent approaches on multiple person segmentation, and all state of the art approaches on the Plant Phenotyping dataset for leaf counting.
no_new_dataset
0.950365
1604.06045
Jason Weston
Jason Weston
Dialog-based Language Learning
null
null
null
null
cs.CL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A long-term goal of machine learning research is to build an intelligent dialog agent. Most research in natural language understanding has focused on learning from fixed training sets of labeled data, with supervision either at the word level (tagging, parsing tasks) or sentence level (question answering, machine translation). This kind of supervision is not realistic of how humans learn, where language is both learned by, and used for, communication. In this work, we study dialog-based language learning, where supervision is given naturally and implicitly in the response of the dialog partner during the conversation. We study this setup in two domains: the bAbI dataset of (Weston et al., 2015) and large-scale question answering from (Dodge et al., 2015). We evaluate a set of baseline learning strategies on these tasks, and show that a novel model incorporating predictive lookahead is a promising approach for learning from a teacher's response. In particular, a surprising result is that it can learn to answer questions correctly without any reward-based supervision at all.
[ { "version": "v1", "created": "Wed, 20 Apr 2016 18:06:49 GMT" }, { "version": "v2", "created": "Mon, 25 Apr 2016 18:27:03 GMT" }, { "version": "v3", "created": "Wed, 18 May 2016 14:02:08 GMT" }, { "version": "v4", "created": "Fri, 20 May 2016 02:53:30 GMT" }, { "version": "v5", "created": "Tue, 23 Aug 2016 18:46:16 GMT" }, { "version": "v6", "created": "Wed, 28 Sep 2016 21:30:27 GMT" }, { "version": "v7", "created": "Mon, 24 Oct 2016 20:00:13 GMT" } ]
2016-10-26T00:00:00
[ [ "Weston", "Jason", "" ] ]
TITLE: Dialog-based Language Learning ABSTRACT: A long-term goal of machine learning research is to build an intelligent dialog agent. Most research in natural language understanding has focused on learning from fixed training sets of labeled data, with supervision either at the word level (tagging, parsing tasks) or sentence level (question answering, machine translation). This kind of supervision is not realistic of how humans learn, where language is both learned by, and used for, communication. In this work, we study dialog-based language learning, where supervision is given naturally and implicitly in the response of the dialog partner during the conversation. We study this setup in two domains: the bAbI dataset of (Weston et al., 2015) and large-scale question answering from (Dodge et al., 2015). We evaluate a set of baseline learning strategies on these tasks, and show that a novel model incorporating predictive lookahead is a promising approach for learning from a teacher's response. In particular, a surprising result is that it can learn to answer questions correctly without any reward-based supervision at all.
no_new_dataset
0.947235
1605.06240
Yangyan Li
Yangyan Li and Soeren Pirk and Hao Su and Charles R. Qi and Leonidas J. Guibas
FPNN: Field Probing Neural Networks for 3D Data
To appear in NIPS 2016
null
null
null
cs.CV
http://creativecommons.org/licenses/by-sa/4.0/
Building discriminative representations for 3D data has been an important task in computer graphics and computer vision research. Convolutional Neural Networks (CNNs) have shown to operate on 2D images with great success for a variety of tasks. Lifting convolution operators to 3D (3DCNNs) seems like a plausible and promising next step. Unfortunately, the computational complexity of 3D CNNs grows cubically with respect to voxel resolution. Moreover, since most 3D geometry representations are boundary based, occupied regions do not increase proportionately with the size of the discretization, resulting in wasted computation. In this work, we represent 3D spaces as volumetric fields, and propose a novel design that employs field probing filters to efficiently extract features from them. Each field probing filter is a set of probing points --- sensors that perceive the space. Our learning algorithm optimizes not only the weights associated with the probing points, but also their locations, which deforms the shape of the probing filters and adaptively distributes them in 3D space. The optimized probing points sense the 3D space "intelligently", rather than operating blindly over the entire domain. We show that field probing is significantly more efficient than 3DCNNs, while providing state-of-the-art performance, on classification tasks for 3D object recognition benchmark datasets.
[ { "version": "v1", "created": "Fri, 20 May 2016 08:15:57 GMT" }, { "version": "v2", "created": "Mon, 29 Aug 2016 07:34:49 GMT" }, { "version": "v3", "created": "Tue, 25 Oct 2016 03:59:16 GMT" } ]
2016-10-26T00:00:00
[ [ "Li", "Yangyan", "" ], [ "Pirk", "Soeren", "" ], [ "Su", "Hao", "" ], [ "Qi", "Charles R.", "" ], [ "Guibas", "Leonidas J.", "" ] ]
TITLE: FPNN: Field Probing Neural Networks for 3D Data ABSTRACT: Building discriminative representations for 3D data has been an important task in computer graphics and computer vision research. Convolutional Neural Networks (CNNs) have shown to operate on 2D images with great success for a variety of tasks. Lifting convolution operators to 3D (3DCNNs) seems like a plausible and promising next step. Unfortunately, the computational complexity of 3D CNNs grows cubically with respect to voxel resolution. Moreover, since most 3D geometry representations are boundary based, occupied regions do not increase proportionately with the size of the discretization, resulting in wasted computation. In this work, we represent 3D spaces as volumetric fields, and propose a novel design that employs field probing filters to efficiently extract features from them. Each field probing filter is a set of probing points --- sensors that perceive the space. Our learning algorithm optimizes not only the weights associated with the probing points, but also their locations, which deforms the shape of the probing filters and adaptively distributes them in 3D space. The optimized probing points sense the 3D space "intelligently", rather than operating blindly over the entire domain. We show that field probing is significantly more efficient than 3DCNNs, while providing state-of-the-art performance, on classification tasks for 3D object recognition benchmark datasets.
no_new_dataset
0.95222
1605.06265
Julien Mairal
Julien Mairal
End-to-End Kernel Learning with Supervised Convolutional Kernel Networks
to appear in Advances in Neural Information Processing Systems (NIPS)
null
null
null
stat.ML cs.CV cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we introduce a new image representation based on a multilayer kernel machine. Unlike traditional kernel methods where data representation is decoupled from the prediction task, we learn how to shape the kernel with supervision. We proceed by first proposing improvements of the recently-introduced convolutional kernel networks (CKNs) in the context of unsupervised learning; then, we derive backpropagation rules to take advantage of labeled training data. The resulting model is a new type of convolutional neural network, where optimizing the filters at each layer is equivalent to learning a linear subspace in a reproducing kernel Hilbert space (RKHS). We show that our method achieves reasonably competitive performance for image classification on some standard "deep learning" datasets such as CIFAR-10 and SVHN, and also for image super-resolution, demonstrating the applicability of our approach to a large variety of image-related tasks.
[ { "version": "v1", "created": "Fri, 20 May 2016 09:52:14 GMT" }, { "version": "v2", "created": "Tue, 25 Oct 2016 12:52:50 GMT" } ]
2016-10-26T00:00:00
[ [ "Mairal", "Julien", "" ] ]
TITLE: End-to-End Kernel Learning with Supervised Convolutional Kernel Networks ABSTRACT: In this paper, we introduce a new image representation based on a multilayer kernel machine. Unlike traditional kernel methods where data representation is decoupled from the prediction task, we learn how to shape the kernel with supervision. We proceed by first proposing improvements of the recently-introduced convolutional kernel networks (CKNs) in the context of unsupervised learning; then, we derive backpropagation rules to take advantage of labeled training data. The resulting model is a new type of convolutional neural network, where optimizing the filters at each layer is equivalent to learning a linear subspace in a reproducing kernel Hilbert space (RKHS). We show that our method achieves reasonably competitive performance for image classification on some standard "deep learning" datasets such as CIFAR-10 and SVHN, and also for image super-resolution, demonstrating the applicability of our approach to a large variety of image-related tasks.
no_new_dataset
0.949809
1610.07677
Edward Yu
Edward Yu, Parth Parekh
A Bayesian Ensemble for Unsupervised Anomaly Detection
null
null
null
null
stat.ML cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Methods for unsupervised anomaly detection suffer from the fact that the data is unlabeled, making it difficult to assess the optimality of detection algorithms. Ensemble learning has shown exceptional results in classification and clustering problems, but has not seen as much research in the context of outlier detection. Existing methods focus on combining output scores of individual detectors, but this leads to outputs that are not easily interpretable. In this paper, we introduce a theoretical foundation for combining individual detectors with Bayesian classifier combination. Not only are posterior distributions easily interpreted as the probability distribution of anomalies, but bias, variance, and individual error rates of detectors are all easily obtained. Performance on real-world datasets shows high accuracy across varied types of time series data.
[ { "version": "v1", "created": "Mon, 24 Oct 2016 23:07:16 GMT" } ]
2016-10-26T00:00:00
[ [ "Yu", "Edward", "" ], [ "Parekh", "Parth", "" ] ]
TITLE: A Bayesian Ensemble for Unsupervised Anomaly Detection ABSTRACT: Methods for unsupervised anomaly detection suffer from the fact that the data is unlabeled, making it difficult to assess the optimality of detection algorithms. Ensemble learning has shown exceptional results in classification and clustering problems, but has not seen as much research in the context of outlier detection. Existing methods focus on combining output scores of individual detectors, but this leads to outputs that are not easily interpretable. In this paper, we introduce a theoretical foundation for combining individual detectors with Bayesian classifier combination. Not only are posterior distributions easily interpreted as the probability distribution of anomalies, but bias, variance, and individual error rates of detectors are all easily obtained. Performance on real-world datasets shows high accuracy across varied types of time series data.
no_new_dataset
0.949623
1610.07722
Ioakeim Perros
Ioakeim Perros and Robert Chen and Richard Vuduc and Jimeng Sun
Sparse Hierarchical Tucker Factorization and its Application to Healthcare
This is an extended version of a paper presented at the 15th IEEE International Conference on Data Mining (ICDM 2015)
null
null
null
cs.LG cs.NA
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a new tensor factorization method, called the Sparse Hierarchical-Tucker (Sparse H-Tucker), for sparse and high-order data tensors. Sparse H-Tucker is inspired by its namesake, the classical Hierarchical Tucker method, which aims to compute a tree-structured factorization of an input data set that may be readily interpreted by a domain expert. However, Sparse H-Tucker uses a nested sampling technique to overcome a key scalability problem in Hierarchical Tucker, which is the creation of an unwieldy intermediate dense core tensor; the result of our approach is a faster, more space-efficient, and more accurate method. We extensively test our method on a real healthcare dataset, which is collected from 30K patients and results in an 18th order sparse data tensor. Unlike competing methods, Sparse H-Tucker can analyze the full data set on a single multi-threaded machine. It can also do so more accurately and in less time than the state-of-the-art: on a 12th order subset of the input data, Sparse H-Tucker is 18x more accurate and 7.5x faster than a previously state-of-the-art method. Even for analyzing low order tensors (e.g., 4-order), our method requires close to an order of magnitude less time and over two orders of magnitude less memory, as compared to traditional tensor factorization methods such as CP and Tucker. Moreover, we observe that Sparse H-Tucker scales nearly linearly in the number of non-zero tensor elements. The resulting model also provides an interpretable disease hierarchy, which is confirmed by a clinical expert.
[ { "version": "v1", "created": "Tue, 25 Oct 2016 04:08:11 GMT" } ]
2016-10-26T00:00:00
[ [ "Perros", "Ioakeim", "" ], [ "Chen", "Robert", "" ], [ "Vuduc", "Richard", "" ], [ "Sun", "Jimeng", "" ] ]
TITLE: Sparse Hierarchical Tucker Factorization and its Application to Healthcare ABSTRACT: We propose a new tensor factorization method, called the Sparse Hierarchical-Tucker (Sparse H-Tucker), for sparse and high-order data tensors. Sparse H-Tucker is inspired by its namesake, the classical Hierarchical Tucker method, which aims to compute a tree-structured factorization of an input data set that may be readily interpreted by a domain expert. However, Sparse H-Tucker uses a nested sampling technique to overcome a key scalability problem in Hierarchical Tucker, which is the creation of an unwieldy intermediate dense core tensor; the result of our approach is a faster, more space-efficient, and more accurate method. We extensively test our method on a real healthcare dataset, which is collected from 30K patients and results in an 18th order sparse data tensor. Unlike competing methods, Sparse H-Tucker can analyze the full data set on a single multi-threaded machine. It can also do so more accurately and in less time than the state-of-the-art: on a 12th order subset of the input data, Sparse H-Tucker is 18x more accurate and 7.5x faster than a previously state-of-the-art method. Even for analyzing low order tensors (e.g., 4-order), our method requires close to an order of magnitude less time and over two orders of magnitude less memory, as compared to traditional tensor factorization methods such as CP and Tucker. Moreover, we observe that Sparse H-Tucker scales nearly linearly in the number of non-zero tensor elements. The resulting model also provides an interpretable disease hierarchy, which is confirmed by a clinical expert.
no_new_dataset
0.949995
1610.07732
Anja Gruenheid
Anja Gruenheid, Donald Kossmann, Divesh Srivastava
Online Event Integration with StoryPivot
null
null
null
null
cs.DB
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Modern data integration systems need to process large amounts of data from a variety of data sources and with real-time integration constraints. They are not only employed in enterprises for managing internal data but are also used for a variety of web services that use techniques such as entity resolution or data cleaning in live systems. In this work, we discuss a new generation of data integration systems that operate on (un-)structured data in an online setting, i.e., systems which process continuously modified datasets upon which the integration task is based. We use as an example of such a system an online event integration system called StoryPivot. It observes events extracted from news articles in data sources such as the 'Guardian' or the 'Washington Post' which are integrated to show users the evolution of real-world stories over time. The design decisions for StoryPivot are influenced by the trade-off between maintaining high quality integration results while at the same time building a system that processes and integrates events in near real-time. We evaluate our design decisions with experiments on two real-world datasets and generalize our findings to other data integration tasks that have a similar system setup.
[ { "version": "v1", "created": "Tue, 25 Oct 2016 05:10:18 GMT" } ]
2016-10-26T00:00:00
[ [ "Gruenheid", "Anja", "" ], [ "Kossmann", "Donald", "" ], [ "Srivastava", "Divesh", "" ] ]
TITLE: Online Event Integration with StoryPivot ABSTRACT: Modern data integration systems need to process large amounts of data from a variety of data sources and with real-time integration constraints. They are not only employed in enterprises for managing internal data but are also used for a variety of web services that use techniques such as entity resolution or data cleaning in live systems. In this work, we discuss a new generation of data integration systems that operate on (un-)structured data in an online setting, i.e., systems which process continuously modified datasets upon which the integration task is based. We use as an example of such a system an online event integration system called StoryPivot. It observes events extracted from news articles in data sources such as the 'Guardian' or the 'Washington Post' which are integrated to show users the evolution of real-world stories over time. The design decisions for StoryPivot are influenced by the trade-off between maintaining high quality integration results while at the same time building a system that processes and integrates events in near real-time. We evaluate our design decisions with experiments on two real-world datasets and generalize our findings to other data integration tasks that have a similar system setup.
no_new_dataset
0.94625
1610.07752
Mrutyunjaya Panda
Mrutyunjaya Panda
Big Models for Big Data using Multi objective averaged one dependence estimators
21 pages, 2 Figures, 10 tables
null
null
null
cs.NE cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Even though, many researchers tried to explore the various possibilities on multi objective feature selection, still it is yet to be explored with best of its capabilities in data mining applications rather than going for developing new ones. In this paper, multi-objective evolutionary algorithm ENORA is used to select the features in a multi-class classification problem. The fusion of AnDE (averaged n-dependence estimators) with n=1, a variant of naive Bayes with efficient feature selection by ENORA is performed in order to obtain a fast hybrid classifier which can effectively learn from big data. This method aims at solving the problem of finding optimal feature subset from full data which at present still remains to be a difficult problem. The efficacy of the obtained classifier is extensively evaluated with a range of most popular 21 real world dataset, ranging from small to big. The results obtained are encouraging in terms of time, Root mean square error, zero-one loss and classification accuracy.
[ { "version": "v1", "created": "Tue, 25 Oct 2016 07:11:11 GMT" } ]
2016-10-26T00:00:00
[ [ "Panda", "Mrutyunjaya", "" ] ]
TITLE: Big Models for Big Data using Multi objective averaged one dependence estimators ABSTRACT: Even though, many researchers tried to explore the various possibilities on multi objective feature selection, still it is yet to be explored with best of its capabilities in data mining applications rather than going for developing new ones. In this paper, multi-objective evolutionary algorithm ENORA is used to select the features in a multi-class classification problem. The fusion of AnDE (averaged n-dependence estimators) with n=1, a variant of naive Bayes with efficient feature selection by ENORA is performed in order to obtain a fast hybrid classifier which can effectively learn from big data. This method aims at solving the problem of finding optimal feature subset from full data which at present still remains to be a difficult problem. The efficacy of the obtained classifier is extensively evaluated with a range of most popular 21 real world dataset, ranging from small to big. The results obtained are encouraging in terms of time, Root mean square error, zero-one loss and classification accuracy.
no_new_dataset
0.947817
1610.07758
Malay Bhattacharyya
Abhisek Dash, Sujoy Chatterjee, Tripti Prasad, and Malay Bhattacharyya
Image Clustering without Ground Truth
GroupSight Workshop, Fourth AAAI Conference on Human Computation and Crowdsourcing (HCOMP 2016), Austin, USA
null
null
null
cs.HC cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Cluster analysis has become one of the most exercised research areas over the past few decades in computer science. As a consequence, numerous clustering algorithms have already been developed to find appropriate partitions of a set of objects. Given multiple such clustering solutions, it is a challenging task to obtain an ensemble of these solutions. This becomes more challenging when the ground truth about the number of clusters is unavailable. In this paper, we introduce a crowd-powered model to collect solutions of image clustering from the general crowd and pose it as a clustering ensemble problem with variable number of clusters. The varying number of clusters basically reflects the crowd workers' perspective toward a particular set of objects. We allow a set of crowd workers to independently cluster the images as per their perceptions. We address the problem by finding out centroid of the clusters using an appropriate distance measure and prioritize the likelihood of similarity of the individual cluster sets. The effectiveness of the proposed method is demonstrated by applying it on multiple artificial datasets obtained from crowd.
[ { "version": "v1", "created": "Tue, 25 Oct 2016 07:34:47 GMT" } ]
2016-10-26T00:00:00
[ [ "Dash", "Abhisek", "" ], [ "Chatterjee", "Sujoy", "" ], [ "Prasad", "Tripti", "" ], [ "Bhattacharyya", "Malay", "" ] ]
TITLE: Image Clustering without Ground Truth ABSTRACT: Cluster analysis has become one of the most exercised research areas over the past few decades in computer science. As a consequence, numerous clustering algorithms have already been developed to find appropriate partitions of a set of objects. Given multiple such clustering solutions, it is a challenging task to obtain an ensemble of these solutions. This becomes more challenging when the ground truth about the number of clusters is unavailable. In this paper, we introduce a crowd-powered model to collect solutions of image clustering from the general crowd and pose it as a clustering ensemble problem with variable number of clusters. The varying number of clusters basically reflects the crowd workers' perspective toward a particular set of objects. We allow a set of crowd workers to independently cluster the images as per their perceptions. We address the problem by finding out centroid of the clusters using an appropriate distance measure and prioritize the likelihood of similarity of the individual cluster sets. The effectiveness of the proposed method is demonstrated by applying it on multiple artificial datasets obtained from crowd.
no_new_dataset
0.949153
1610.07809
Florian Boudin
Florian Boudin, Hugo Mougard, Damien Cram
How Document Pre-processing affects Keyphrase Extraction Performance
Accepted at the COLING 2016 Workshop on Noisy User-generated Text (WNUT)
null
null
null
cs.CL
http://creativecommons.org/licenses/by/4.0/
The SemEval-2010 benchmark dataset has brought renewed attention to the task of automatic keyphrase extraction. This dataset is made up of scientific articles that were automatically converted from PDF format to plain text and thus require careful preprocessing so that irrevelant spans of text do not negatively affect keyphrase extraction performance. In previous work, a wide range of document preprocessing techniques were described but their impact on the overall performance of keyphrase extraction models is still unexplored. Here, we re-assess the performance of several keyphrase extraction models and measure their robustness against increasingly sophisticated levels of document preprocessing.
[ { "version": "v1", "created": "Tue, 25 Oct 2016 09:59:13 GMT" } ]
2016-10-26T00:00:00
[ [ "Boudin", "Florian", "" ], [ "Mougard", "Hugo", "" ], [ "Cram", "Damien", "" ] ]
TITLE: How Document Pre-processing affects Keyphrase Extraction Performance ABSTRACT: The SemEval-2010 benchmark dataset has brought renewed attention to the task of automatic keyphrase extraction. This dataset is made up of scientific articles that were automatically converted from PDF format to plain text and thus require careful preprocessing so that irrevelant spans of text do not negatively affect keyphrase extraction performance. In previous work, a wide range of document preprocessing techniques were described but their impact on the overall performance of keyphrase extraction models is still unexplored. Here, we re-assess the performance of several keyphrase extraction models and measure their robustness against increasingly sophisticated levels of document preprocessing.
no_new_dataset
0.919859
1610.07882
Michael Blot
Michael Blot, Matthieu Cord, Nicolas Thome
Maxmin convolutional neural networks for image classification
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Convolutional neural networks (CNN) are widely used in computer vision, especially in image classification. However, the way in which information and invariance properties are encoded through in deep CNN architectures is still an open question. In this paper, we propose to modify the standard convo- lutional block of CNN in order to transfer more information layer after layer while keeping some invariance within the net- work. Our main idea is to exploit both positive and negative high scores obtained in the convolution maps. This behav- ior is obtained by modifying the traditional activation func- tion step before pooling. We are doubling the maps with spe- cific activations functions, called MaxMin strategy, in order to achieve our pipeline. Extensive experiments on two classical datasets, MNIST and CIFAR-10, show that our deep MaxMin convolutional net outperforms standard CNN.
[ { "version": "v1", "created": "Tue, 25 Oct 2016 14:04:11 GMT" } ]
2016-10-26T00:00:00
[ [ "Blot", "Michael", "" ], [ "Cord", "Matthieu", "" ], [ "Thome", "Nicolas", "" ] ]
TITLE: Maxmin convolutional neural networks for image classification ABSTRACT: Convolutional neural networks (CNN) are widely used in computer vision, especially in image classification. However, the way in which information and invariance properties are encoded through in deep CNN architectures is still an open question. In this paper, we propose to modify the standard convo- lutional block of CNN in order to transfer more information layer after layer while keeping some invariance within the net- work. Our main idea is to exploit both positive and negative high scores obtained in the convolution maps. This behav- ior is obtained by modifying the traditional activation func- tion step before pooling. We are doubling the maps with spe- cific activations functions, called MaxMin strategy, in order to achieve our pipeline. Extensive experiments on two classical datasets, MNIST and CIFAR-10, show that our deep MaxMin convolutional net outperforms standard CNN.
no_new_dataset
0.951997
1610.07918
Yossi Adi
Yossi Adi, Joseph Keshet, Emily Cibelli, Matthew Goldrick
Sequence Segmentation Using Joint RNN and Structured Prediction Models
under review
null
null
null
cs.CL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We describe and analyze a simple and effective algorithm for sequence segmentation applied to speech processing tasks. We propose a neural architecture that is composed of two modules trained jointly: a recurrent neural network (RNN) module and a structured prediction model. The RNN outputs are considered as feature functions to the structured model. The overall model is trained with a structured loss function which can be designed to the given segmentation task. We demonstrate the effectiveness of our method by applying it to two simple tasks commonly used in phonetic studies: word segmentation and voice onset time segmentation. Results sug- gest the proposed model is superior to previous methods, ob- taining state-of-the-art results on the tested datasets.
[ { "version": "v1", "created": "Tue, 25 Oct 2016 15:21:25 GMT" } ]
2016-10-26T00:00:00
[ [ "Adi", "Yossi", "" ], [ "Keshet", "Joseph", "" ], [ "Cibelli", "Emily", "" ], [ "Goldrick", "Matthew", "" ] ]
TITLE: Sequence Segmentation Using Joint RNN and Structured Prediction Models ABSTRACT: We describe and analyze a simple and effective algorithm for sequence segmentation applied to speech processing tasks. We propose a neural architecture that is composed of two modules trained jointly: a recurrent neural network (RNN) module and a structured prediction model. The RNN outputs are considered as feature functions to the structured model. The overall model is trained with a structured loss function which can be designed to the given segmentation task. We demonstrate the effectiveness of our method by applying it to two simple tasks commonly used in phonetic studies: word segmentation and voice onset time segmentation. Results sug- gest the proposed model is superior to previous methods, ob- taining state-of-the-art results on the tested datasets.
no_new_dataset
0.952706
1610.08015
Nicola Wadeson Dr
Nicola Wadeson, Mark Basham
Savu: A Python-based, MPI Framework for Simultaneous Processing of Multiple, N-dimensional, Large Tomography Datasets
10 pages, 10 figures, 1 table
null
null
null
cs.DC cs.CV cs.DB
http://creativecommons.org/licenses/by/4.0/
Diamond Light Source (DLS), the UK synchrotron facility, attracts scientists from across the world to perform ground-breaking x-ray experiments. With over 3000 scientific users per year, vast amounts of data are collected across the experimental beamlines, with the highest volume of data collected during tomographic imaging experiments. A growing interest in tomography as an imaging technique, has led to an expansion in the range of experiments performed, in addition to a growth in the size of the data per experiment. Savu is a portable, flexible, scientific processing pipeline capable of processing multiple, n-dimensional datasets in serial on a PC, or in parallel across a cluster. Developed at DLS, and successfully deployed across the beamlines, it uses a modular plugin format to enable experiment-specific processing and utilises parallel HDF5 to remove RAM restrictions. The Savu design, described throughout this paper, focuses on easy integration of existing and new functionality, flexibility and ease of use for users and developers alike.
[ { "version": "v1", "created": "Mon, 24 Oct 2016 13:22:09 GMT" } ]
2016-10-26T00:00:00
[ [ "Wadeson", "Nicola", "" ], [ "Basham", "Mark", "" ] ]
TITLE: Savu: A Python-based, MPI Framework for Simultaneous Processing of Multiple, N-dimensional, Large Tomography Datasets ABSTRACT: Diamond Light Source (DLS), the UK synchrotron facility, attracts scientists from across the world to perform ground-breaking x-ray experiments. With over 3000 scientific users per year, vast amounts of data are collected across the experimental beamlines, with the highest volume of data collected during tomographic imaging experiments. A growing interest in tomography as an imaging technique, has led to an expansion in the range of experiments performed, in addition to a growth in the size of the data per experiment. Savu is a portable, flexible, scientific processing pipeline capable of processing multiple, n-dimensional datasets in serial on a PC, or in parallel across a cluster. Developed at DLS, and successfully deployed across the beamlines, it uses a modular plugin format to enable experiment-specific processing and utilises parallel HDF5 to remove RAM restrictions. The Savu design, described throughout this paper, focuses on easy integration of existing and new functionality, flexibility and ease of use for users and developers alike.
no_new_dataset
0.945851
1511.04404
Oncel Tuzel
Oncel Tuzel and Tim K. Marks and Salil Tambe
Robust Face Alignment Using a Mixture of Invariant Experts
17 pages, 6 figures
Proceedings of 14th European Conference on Computer Vision (ECCV), Amsterdam, The Netherlands, October 11-14, 2016, pp 825-841
10.1007/978-3-319-46454-1_50
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Face alignment, which is the task of finding the locations of a set of facial landmark points in an image of a face, is useful in widespread application areas. Face alignment is particularly challenging when there are large variations in pose (in-plane and out-of-plane rotations) and facial expression. To address this issue, we propose a cascade in which each stage consists of a mixture of regression experts. Each expert learns a customized regression model that is specialized to a different subset of the joint space of pose and expressions. The system is invariant to a predefined class of transformations (e.g., affine), because the input is transformed to match each expert's prototype shape before the regression is applied. We also present a method to include deformation constraints within the discriminative alignment framework, which makes our algorithm more robust. Our algorithm significantly outperforms previous methods on publicly available face alignment datasets.
[ { "version": "v1", "created": "Fri, 13 Nov 2015 19:14:51 GMT" }, { "version": "v2", "created": "Sun, 23 Oct 2016 18:31:06 GMT" } ]
2016-10-25T00:00:00
[ [ "Tuzel", "Oncel", "" ], [ "Marks", "Tim K.", "" ], [ "Tambe", "Salil", "" ] ]
TITLE: Robust Face Alignment Using a Mixture of Invariant Experts ABSTRACT: Face alignment, which is the task of finding the locations of a set of facial landmark points in an image of a face, is useful in widespread application areas. Face alignment is particularly challenging when there are large variations in pose (in-plane and out-of-plane rotations) and facial expression. To address this issue, we propose a cascade in which each stage consists of a mixture of regression experts. Each expert learns a customized regression model that is specialized to a different subset of the joint space of pose and expressions. The system is invariant to a predefined class of transformations (e.g., affine), because the input is transformed to match each expert's prototype shape before the regression is applied. We also present a method to include deformation constraints within the discriminative alignment framework, which makes our algorithm more robust. Our algorithm significantly outperforms previous methods on publicly available face alignment datasets.
no_new_dataset
0.952926
1511.05616
Hexiang Hu
Hexiang Hu, Guang-Tong Zhou, Zhiwei Deng, Zicheng Liao, Greg Mori
Learning Structured Inference Neural Networks with Label Relations
Conference on Computer Vision and Pattern Recognition(CVPR) 2016
null
null
null
cs.CV cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Images of scenes have various objects as well as abundant attributes, and diverse levels of visual categorization are possible. A natural image could be assigned with fine-grained labels that describe major components, coarse-grained labels that depict high level abstraction or a set of labels that reveal attributes. Such categorization at different concept layers can be modeled with label graphs encoding label information. In this paper, we exploit this rich information with a state-of-art deep learning framework, and propose a generic structured model that leverages diverse label relations to improve image classification performance. Our approach employs a novel stacked label prediction neural network, capturing both inter-level and intra-level label semantics. We evaluate our method on benchmark image datasets, and empirical results illustrate the efficacy of our model.
[ { "version": "v1", "created": "Tue, 17 Nov 2015 23:22:25 GMT" }, { "version": "v2", "created": "Thu, 19 Nov 2015 06:13:16 GMT" }, { "version": "v3", "created": "Fri, 8 Apr 2016 05:04:52 GMT" }, { "version": "v4", "created": "Mon, 24 Oct 2016 18:20:20 GMT" } ]
2016-10-25T00:00:00
[ [ "Hu", "Hexiang", "" ], [ "Zhou", "Guang-Tong", "" ], [ "Deng", "Zhiwei", "" ], [ "Liao", "Zicheng", "" ], [ "Mori", "Greg", "" ] ]
TITLE: Learning Structured Inference Neural Networks with Label Relations ABSTRACT: Images of scenes have various objects as well as abundant attributes, and diverse levels of visual categorization are possible. A natural image could be assigned with fine-grained labels that describe major components, coarse-grained labels that depict high level abstraction or a set of labels that reveal attributes. Such categorization at different concept layers can be modeled with label graphs encoding label information. In this paper, we exploit this rich information with a state-of-art deep learning framework, and propose a generic structured model that leverages diverse label relations to improve image classification performance. Our approach employs a novel stacked label prediction neural network, capturing both inter-level and intra-level label semantics. We evaluate our method on benchmark image datasets, and empirical results illustrate the efficacy of our model.
no_new_dataset
0.948251