id
stringlengths
9
16
submitter
stringlengths
3
64
authors
stringlengths
5
6.63k
title
stringlengths
7
245
comments
stringlengths
1
482
journal-ref
stringlengths
4
382
doi
stringlengths
9
151
report-no
stringclasses
984 values
categories
stringlengths
5
108
license
stringclasses
9 values
abstract
stringlengths
83
3.41k
versions
listlengths
1
20
update_date
timestamp[s]date
2007-05-23 00:00:00
2025-04-11 00:00:00
authors_parsed
sequencelengths
1
427
prompt
stringlengths
166
3.49k
label
stringclasses
2 values
prob
float64
0.5
0.98
1512.06474
Theodoros Rekatsinas
Manas Joglekar and Theodoros Rekatsinas and Hector Garcia-Molina and Aditya Parameswaran and Christopher R\'e
SLiMFast: Guaranteed Results for Data Fusion and Source Reliability
null
null
null
null
cs.DB
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We focus on data fusion, i.e., the problem of unifying conflicting data from data sources into a single representation by estimating the source accuracies. We propose SLiMFast, a framework that expresses data fusion as a statistical learning problem over discriminative probabilistic models, which in many cases correspond to logistic regression. In contrast to previous approaches that use complex generative models, discriminative models make fewer distributional assumptions over data sources and allow us to obtain rigorous theoretical guarantees. Furthermore, we show how SLiMFast enables incorporating domain knowledge into data fusion, yielding accuracy improvements of up to 50\% over state-of-the-art baselines. Building upon our theoretical results, we design an optimizer that obviates the need for users to manually select an algorithm for learning SLiMFast's parameters. We validate our optimizer on multiple real-world datasets and show that it can accurately predict the learning algorithm that yields the best data fusion results.
[ { "version": "v1", "created": "Mon, 21 Dec 2015 02:28:17 GMT" }, { "version": "v2", "created": "Fri, 13 May 2016 22:55:37 GMT" }, { "version": "v3", "created": "Sat, 12 Nov 2016 17:33:47 GMT" } ]
2016-11-15T00:00:00
[ [ "Joglekar", "Manas", "" ], [ "Rekatsinas", "Theodoros", "" ], [ "Garcia-Molina", "Hector", "" ], [ "Parameswaran", "Aditya", "" ], [ "Ré", "Christopher", "" ] ]
TITLE: SLiMFast: Guaranteed Results for Data Fusion and Source Reliability ABSTRACT: We focus on data fusion, i.e., the problem of unifying conflicting data from data sources into a single representation by estimating the source accuracies. We propose SLiMFast, a framework that expresses data fusion as a statistical learning problem over discriminative probabilistic models, which in many cases correspond to logistic regression. In contrast to previous approaches that use complex generative models, discriminative models make fewer distributional assumptions over data sources and allow us to obtain rigorous theoretical guarantees. Furthermore, we show how SLiMFast enables incorporating domain knowledge into data fusion, yielding accuracy improvements of up to 50\% over state-of-the-art baselines. Building upon our theoretical results, we design an optimizer that obviates the need for users to manually select an algorithm for learning SLiMFast's parameters. We validate our optimizer on multiple real-world datasets and show that it can accurately predict the learning algorithm that yields the best data fusion results.
no_new_dataset
0.945801
1602.00994
Kai Zhao
Kai Zhao, C Mohan Prasath, Sasu Tarkoma
Automatic City Region Analysis for Urban Routing
In proceedings of the IEEE International Conference on Data Mining (ICDM) workshop 2015
null
10.1109/ICDMW.2015.176
null
cs.SI physics.soc-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
There are different functional regions in cities such as tourist attractions, shopping centers, workplaces and residential places. The human mobility patterns for different functional regions are different, e.g., people usually go to work during daytime on weekdays, and visit shopping centers after work. In this paper, we analyse urban human mobility patterns and infer the functions of the regions in three cities. The analysis is based on three large taxi GPS datasets in Rome, San Francisco and Beijing containing 21 million, 11 million and 17 million GPS points respectively. We categorized the city regions into four kinds of places, workplaces, entertainment places, residential places and other places. First, we provide a new quad-tree region division method based on the taxi visits. Second, we use the association rule to infer the functional regions in these three cities according to temporal human mobility patterns. Third, we show that these identified functional regions can help us deliver data in network applications, such as urban Delay Tolerant Networks (DTNs), more efficiently. The new functional-regions-based DTNs algorithm achieves up to 183% improvement in terms of delivery ratio.
[ { "version": "v1", "created": "Tue, 2 Feb 2016 16:18:58 GMT" } ]
2016-11-15T00:00:00
[ [ "Zhao", "Kai", "" ], [ "Prasath", "C Mohan", "" ], [ "Tarkoma", "Sasu", "" ] ]
TITLE: Automatic City Region Analysis for Urban Routing ABSTRACT: There are different functional regions in cities such as tourist attractions, shopping centers, workplaces and residential places. The human mobility patterns for different functional regions are different, e.g., people usually go to work during daytime on weekdays, and visit shopping centers after work. In this paper, we analyse urban human mobility patterns and infer the functions of the regions in three cities. The analysis is based on three large taxi GPS datasets in Rome, San Francisco and Beijing containing 21 million, 11 million and 17 million GPS points respectively. We categorized the city regions into four kinds of places, workplaces, entertainment places, residential places and other places. First, we provide a new quad-tree region division method based on the taxi visits. Second, we use the association rule to infer the functional regions in these three cities according to temporal human mobility patterns. Third, we show that these identified functional regions can help us deliver data in network applications, such as urban Delay Tolerant Networks (DTNs), more efficiently. The new functional-regions-based DTNs algorithm achieves up to 183% improvement in terms of delivery ratio.
no_new_dataset
0.947769
1604.00147
Lijuan Zhou
Lijuan Zhou, Wanqing Li, and Philip Ogunbona
Learning a Pose Lexicon for Semantic Action Recognition
Accepted by the 2016 IEEE International Conference on Multimedia and Expo (ICME 2016). 6 pages paper and 4 pages supplementary material
null
10.1109/ICME.2016.7552882
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper presents a novel method for learning a pose lexicon comprising semantic poses defined by textual instructions and their associated visual poses defined by visual features. The proposed method simultaneously takes two input streams, semantic poses and visual pose candidates, and statistically learns a mapping between them to construct the lexicon. With the learned lexicon, action recognition can be cast as the problem of finding the maximum translation probability of a sequence of semantic poses given a stream of visual pose candidates. Experiments evaluating pre-trained and zero-shot action recognition conducted on MSRC-12 gesture and WorkoutSu-10 exercise datasets were used to verify the efficacy of the proposed method.
[ { "version": "v1", "created": "Fri, 1 Apr 2016 06:24:31 GMT" } ]
2016-11-15T00:00:00
[ [ "Zhou", "Lijuan", "" ], [ "Li", "Wanqing", "" ], [ "Ogunbona", "Philip", "" ] ]
TITLE: Learning a Pose Lexicon for Semantic Action Recognition ABSTRACT: This paper presents a novel method for learning a pose lexicon comprising semantic poses defined by textual instructions and their associated visual poses defined by visual features. The proposed method simultaneously takes two input streams, semantic poses and visual pose candidates, and statistically learns a mapping between them to construct the lexicon. With the learned lexicon, action recognition can be cast as the problem of finding the maximum translation probability of a sequence of semantic poses given a stream of visual pose candidates. Experiments evaluating pre-trained and zero-shot action recognition conducted on MSRC-12 gesture and WorkoutSu-10 exercise datasets were used to verify the efficacy of the proposed method.
no_new_dataset
0.93852
1604.07045
Mario Valerio Giuffrida
Mario Valerio Giuffrida and Sotirios A. Tsaftaris
Rotation-Invariant Restricted Boltzmann Machine Using Shared Gradient Filters
8 pages, 3 figures, 1 table
null
10.1007/978-3-319-44781-0_57
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Finding suitable features has been an essential problem in computer vision. We focus on Restricted Boltzmann Machines (RBMs), which, despite their versatility, cannot accommodate transformations that may occur in the scene. As a result, several approaches have been proposed that consider a set of transformations, which are used to either augment the training set or transform the actual learned filters. In this paper, we propose the Explicit Rotation-Invariant Restricted Boltzmann Machine, which exploits prior information coming from the dominant orientation of images. Our model extends the standard RBM, by adding a suitable number of weight matrices, associated with each dominant gradient. We show that our approach is able to learn rotation-invariant features, comparing it with the classic formulation of RBM on the MNIST benchmark dataset. Overall, requiring less hidden units, our method learns compact features, which are robust to rotations.
[ { "version": "v1", "created": "Sun, 24 Apr 2016 15:56:18 GMT" }, { "version": "v2", "created": "Thu, 23 Jun 2016 09:59:47 GMT" } ]
2016-11-15T00:00:00
[ [ "Giuffrida", "Mario Valerio", "" ], [ "Tsaftaris", "Sotirios A.", "" ] ]
TITLE: Rotation-Invariant Restricted Boltzmann Machine Using Shared Gradient Filters ABSTRACT: Finding suitable features has been an essential problem in computer vision. We focus on Restricted Boltzmann Machines (RBMs), which, despite their versatility, cannot accommodate transformations that may occur in the scene. As a result, several approaches have been proposed that consider a set of transformations, which are used to either augment the training set or transform the actual learned filters. In this paper, we propose the Explicit Rotation-Invariant Restricted Boltzmann Machine, which exploits prior information coming from the dominant orientation of images. Our model extends the standard RBM, by adding a suitable number of weight matrices, associated with each dominant gradient. We show that our approach is able to learn rotation-invariant features, comparing it with the classic formulation of RBM on the MNIST benchmark dataset. Overall, requiring less hidden units, our method learns compact features, which are robust to rotations.
no_new_dataset
0.949902
1604.07638
Yixin Bao
Yixin Bao, Xiaoke Wang, Zhi Wang, Chuan Wu, Francis C.M. Lau
Online Influence Maximization in Non-Stationary Social Networks
10 pages. To appear in IEEE/ACM IWQoS 2016. Full version
null
10.1109/IWQoS.2016.7590438
null
cs.SI cs.DS cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Social networks have been popular platforms for information propagation. An important use case is viral marketing: given a promotion budget, an advertiser can choose some influential users as the seed set and provide them free or discounted sample products; in this way, the advertiser hopes to increase the popularity of the product in the users' friend circles by the world-of-mouth effect, and thus maximizes the number of users that information of the production can reach. There has been a body of literature studying the influence maximization problem. Nevertheless, the existing studies mostly investigate the problem on a one-off basis, assuming fixed known influence probabilities among users, or the knowledge of the exact social network topology. In practice, the social network topology and the influence probabilities are typically unknown to the advertiser, which can be varying over time, i.e., in cases of newly established, strengthened or weakened social ties. In this paper, we focus on a dynamic non-stationary social network and design a randomized algorithm, RSB, based on multi-armed bandit optimization, to maximize influence propagation over time. The algorithm produces a sequence of online decisions and calibrates its explore-exploit strategy utilizing outcomes of previous decisions. It is rigorously proven to achieve an upper-bounded regret in reward and applicable to large-scale social networks. Practical effectiveness of the algorithm is evaluated using both synthetic and real-world datasets, which demonstrates that our algorithm outperforms previous stationary methods under non-stationary conditions.
[ { "version": "v1", "created": "Tue, 26 Apr 2016 12:02:55 GMT" } ]
2016-11-15T00:00:00
[ [ "Bao", "Yixin", "" ], [ "Wang", "Xiaoke", "" ], [ "Wang", "Zhi", "" ], [ "Wu", "Chuan", "" ], [ "Lau", "Francis C. M.", "" ] ]
TITLE: Online Influence Maximization in Non-Stationary Social Networks ABSTRACT: Social networks have been popular platforms for information propagation. An important use case is viral marketing: given a promotion budget, an advertiser can choose some influential users as the seed set and provide them free or discounted sample products; in this way, the advertiser hopes to increase the popularity of the product in the users' friend circles by the world-of-mouth effect, and thus maximizes the number of users that information of the production can reach. There has been a body of literature studying the influence maximization problem. Nevertheless, the existing studies mostly investigate the problem on a one-off basis, assuming fixed known influence probabilities among users, or the knowledge of the exact social network topology. In practice, the social network topology and the influence probabilities are typically unknown to the advertiser, which can be varying over time, i.e., in cases of newly established, strengthened or weakened social ties. In this paper, we focus on a dynamic non-stationary social network and design a randomized algorithm, RSB, based on multi-armed bandit optimization, to maximize influence propagation over time. The algorithm produces a sequence of online decisions and calibrates its explore-exploit strategy utilizing outcomes of previous decisions. It is rigorously proven to achieve an upper-bounded regret in reward and applicable to large-scale social networks. Practical effectiveness of the algorithm is evaluated using both synthetic and real-world datasets, which demonstrates that our algorithm outperforms previous stationary methods under non-stationary conditions.
no_new_dataset
0.943815
1605.03259
Chi Su
Chi Su, Shiliang Zhang, Junliang Xing, Wen Gao and Qi Tian
Deep Attributes Driven Multi-Camera Person Re-identification
Person Re-identification; 17 pages; 5 figures; In IEEE ECCV 2016
null
10.1007/978-3-319-46475-6_30
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The visual appearance of a person is easily affected by many factors like pose variations, viewpoint changes and camera parameter differences. This makes person Re-Identification (ReID) among multiple cameras a very challenging task. This work is motivated to learn mid-level human attributes which are robust to such visual appearance variations. And we propose a semi-supervised attribute learning framework which progressively boosts the accuracy of attributes only using a limited number of labeled data. Specifically, this framework involves a three-stage training. A deep Convolutional Neural Network (dCNN) is first trained on an independent dataset labeled with attributes. Then it is fine-tuned on another dataset only labeled with person IDs using our defined triplet loss. Finally, the updated dCNN predicts attribute labels for the target dataset, which is combined with the independent dataset for the final round of fine-tuning. The predicted attributes, namely \emph{deep attributes} exhibit superior generalization ability across different datasets. By directly using the deep attributes with simple Cosine distance, we have obtained surprisingly good accuracy on four person ReID datasets. Experiments also show that a simple metric learning modular further boosts our method, making it significantly outperform many recent works.
[ { "version": "v1", "created": "Wed, 11 May 2016 02:05:22 GMT" }, { "version": "v2", "created": "Tue, 9 Aug 2016 05:58:03 GMT" } ]
2016-11-15T00:00:00
[ [ "Su", "Chi", "" ], [ "Zhang", "Shiliang", "" ], [ "Xing", "Junliang", "" ], [ "Gao", "Wen", "" ], [ "Tian", "Qi", "" ] ]
TITLE: Deep Attributes Driven Multi-Camera Person Re-identification ABSTRACT: The visual appearance of a person is easily affected by many factors like pose variations, viewpoint changes and camera parameter differences. This makes person Re-Identification (ReID) among multiple cameras a very challenging task. This work is motivated to learn mid-level human attributes which are robust to such visual appearance variations. And we propose a semi-supervised attribute learning framework which progressively boosts the accuracy of attributes only using a limited number of labeled data. Specifically, this framework involves a three-stage training. A deep Convolutional Neural Network (dCNN) is first trained on an independent dataset labeled with attributes. Then it is fine-tuned on another dataset only labeled with person IDs using our defined triplet loss. Finally, the updated dCNN predicts attribute labels for the target dataset, which is combined with the independent dataset for the final round of fine-tuning. The predicted attributes, namely \emph{deep attributes} exhibit superior generalization ability across different datasets. By directly using the deep attributes with simple Cosine distance, we have obtained surprisingly good accuracy on four person ReID datasets. Experiments also show that a simple metric learning modular further boosts our method, making it significantly outperform many recent works.
no_new_dataset
0.945901
1605.04478
Hamid Tizhoosh
Mina Nouredanesh, Hamid R. Tizhoosh, Ershad Banijamali
Gabor Barcodes for Medical Image Retrieval
To appear in proceedings of The 2016 IEEE International Conference on Image Processing (ICIP 2016), Sep 25-28, 2016, Phoenix, Arizona, USA
null
10.1109/ICIP.2016.7532807
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In recent years, advances in medical imaging have led to the emergence of massive databases, containing images from a diverse range of modalities. This has significantly heightened the need for automated annotation of the images on one side, and fast and memory-efficient content-based image retrieval systems on the other side. Binary descriptors have recently gained more attention as a potential vehicle to achieve these goals. One of the recently introduced binary descriptors for tagging of medical images are Radon barcodes (RBCs) that are driven from Radon transform via local thresholding. Gabor transform is also a powerful transform to extract texture-based information. Gabor features have exhibited robustness against rotation, scale, and also photometric disturbances, such as illumination changes and image noise in many applications. This paper introduces Gabor Barcodes (GBCs), as a novel framework for the image annotation. To find the most discriminative GBC for a given query image, the effects of employing Gabor filters with different parameters, i.e., different sets of scales and orientations, are investigated, resulting in different barcode lengths and retrieval performances. The proposed method has been evaluated on the IRMA dataset with 193 classes comprising of 12,677 x-ray images for indexing, and 1,733 x-rays images for testing. A total error score as low as $351$ ($\approx 80\%$ accuracy for the first hit) was achieved.
[ { "version": "v1", "created": "Sat, 14 May 2016 22:39:29 GMT" } ]
2016-11-15T00:00:00
[ [ "Nouredanesh", "Mina", "" ], [ "Tizhoosh", "Hamid R.", "" ], [ "Banijamali", "Ershad", "" ] ]
TITLE: Gabor Barcodes for Medical Image Retrieval ABSTRACT: In recent years, advances in medical imaging have led to the emergence of massive databases, containing images from a diverse range of modalities. This has significantly heightened the need for automated annotation of the images on one side, and fast and memory-efficient content-based image retrieval systems on the other side. Binary descriptors have recently gained more attention as a potential vehicle to achieve these goals. One of the recently introduced binary descriptors for tagging of medical images are Radon barcodes (RBCs) that are driven from Radon transform via local thresholding. Gabor transform is also a powerful transform to extract texture-based information. Gabor features have exhibited robustness against rotation, scale, and also photometric disturbances, such as illumination changes and image noise in many applications. This paper introduces Gabor Barcodes (GBCs), as a novel framework for the image annotation. To find the most discriminative GBC for a given query image, the effects of employing Gabor filters with different parameters, i.e., different sets of scales and orientations, are investigated, resulting in different barcode lengths and retrieval performances. The proposed method has been evaluated on the IRMA dataset with 193 classes comprising of 12,677 x-ray images for indexing, and 1,733 x-rays images for testing. A total error score as low as $351$ ($\approx 80\%$ accuracy for the first hit) was achieved.
no_new_dataset
0.949949
1605.09080
Forough Arabshahi
Forough Arabshahi, Animashree Anandkumar
Spectral Methods for Correlated Topic Models
null
null
null
null
cs.LG stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we propose guaranteed spectral methods for learning a broad range of topic models, which generalize the popular Latent Dirichlet Allocation (LDA). We overcome the limitation of LDA to incorporate arbitrary topic correlations, by assuming that the hidden topic proportions are drawn from a flexible class of Normalized Infinitely Divisible (NID) distributions. NID distributions are generated through the process of normalizing a family of independent Infinitely Divisible (ID) random variables. The Dirichlet distribution is a special case obtained by normalizing a set of Gamma random variables. We prove that this flexible topic model class can be learned via spectral methods using only moments up to the third order, with (low order) polynomial sample and computational complexity. The proof is based on a key new technique derived here that allows us to diagonalize the moments of the NID distribution through an efficient procedure that requires evaluating only univariate integrals, despite the fact that we are handling high dimensional multivariate moments. In order to assess the performance of our proposed Latent NID topic model, we use two real datasets of articles collected from New York Times and Pubmed. Our experiments yield improved perplexity on both datasets compared with the baseline.
[ { "version": "v1", "created": "Mon, 30 May 2016 00:32:11 GMT" }, { "version": "v2", "created": "Tue, 31 May 2016 14:30:11 GMT" }, { "version": "v3", "created": "Sun, 5 Jun 2016 08:27:34 GMT" }, { "version": "v4", "created": "Sat, 20 Aug 2016 01:44:30 GMT" }, { "version": "v5", "created": "Sun, 13 Nov 2016 20:24:02 GMT" } ]
2016-11-15T00:00:00
[ [ "Arabshahi", "Forough", "" ], [ "Anandkumar", "Animashree", "" ] ]
TITLE: Spectral Methods for Correlated Topic Models ABSTRACT: In this paper, we propose guaranteed spectral methods for learning a broad range of topic models, which generalize the popular Latent Dirichlet Allocation (LDA). We overcome the limitation of LDA to incorporate arbitrary topic correlations, by assuming that the hidden topic proportions are drawn from a flexible class of Normalized Infinitely Divisible (NID) distributions. NID distributions are generated through the process of normalizing a family of independent Infinitely Divisible (ID) random variables. The Dirichlet distribution is a special case obtained by normalizing a set of Gamma random variables. We prove that this flexible topic model class can be learned via spectral methods using only moments up to the third order, with (low order) polynomial sample and computational complexity. The proof is based on a key new technique derived here that allows us to diagonalize the moments of the NID distribution through an efficient procedure that requires evaluating only univariate integrals, despite the fact that we are handling high dimensional multivariate moments. In order to assess the performance of our proposed Latent NID topic model, we use two real datasets of articles collected from New York Times and Pubmed. Our experiments yield improved perplexity on both datasets compared with the baseline.
no_new_dataset
0.944228
1607.00455
Ehsan Hosseini-Asl
Ehsan Hosseini-Asl, Robert Keynto, Ayman El-Baz
Alzheimer's Disease Diagnostics by Adaptation of 3D Convolutional Network
This paper is accepted for publication at IEEE ICIP 2016 conference
null
10.1109/ICIP.2016.7532332
null
cs.LG q-bio.NC stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Early diagnosis, playing an important role in preventing progress and treating the Alzheimer\{'}s disease (AD), is based on classification of features extracted from brain images. The features have to accurately capture main AD-related variations of anatomical brain structures, such as, e.g., ventricles size, hippocampus shape, cortical thickness, and brain volume. This paper proposed to predict the AD with a deep 3D convolutional neural network (3D-CNN), which can learn generic features capturing AD biomarkers and adapt to different domain datasets. The 3D-CNN is built upon a 3D convolutional autoencoder, which is pre-trained to capture anatomical shape variations in structural brain MRI scans. Fully connected upper layers of the 3D-CNN are then fine-tuned for each task-specific AD classification. Experiments on the CADDementia MRI dataset with no skull-stripping preprocessing have shown our 3D-CNN outperforms several conventional classifiers by accuracy. Abilities of the 3D-CNN to generalize the features learnt and adapt to other domains have been validated on the ADNI dataset.
[ { "version": "v1", "created": "Sat, 2 Jul 2016 02:55:16 GMT" } ]
2016-11-15T00:00:00
[ [ "Hosseini-Asl", "Ehsan", "" ], [ "Keynto", "Robert", "" ], [ "El-Baz", "Ayman", "" ] ]
TITLE: Alzheimer's Disease Diagnostics by Adaptation of 3D Convolutional Network ABSTRACT: Early diagnosis, playing an important role in preventing progress and treating the Alzheimer\{'}s disease (AD), is based on classification of features extracted from brain images. The features have to accurately capture main AD-related variations of anatomical brain structures, such as, e.g., ventricles size, hippocampus shape, cortical thickness, and brain volume. This paper proposed to predict the AD with a deep 3D convolutional neural network (3D-CNN), which can learn generic features capturing AD biomarkers and adapt to different domain datasets. The 3D-CNN is built upon a 3D convolutional autoencoder, which is pre-trained to capture anatomical shape variations in structural brain MRI scans. Fully connected upper layers of the 3D-CNN are then fine-tuned for each task-specific AD classification. Experiments on the CADDementia MRI dataset with no skull-stripping preprocessing have shown our 3D-CNN outperforms several conventional classifiers by accuracy. Abilities of the 3D-CNN to generalize the features learnt and adapt to other domains have been validated on the ADNI dataset.
no_new_dataset
0.948298
1607.05387
Hanock Kwak
Hanock Kwak, Byoung-Tak Zhang
Generating Images Part by Part with Composite Generative Adversarial Networks
null
null
null
null
cs.AI cs.CV cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Image generation remains a fundamental problem in artificial intelligence in general and deep learning in specific. The generative adversarial network (GAN) was successful in generating high quality samples of natural images. We propose a model called composite generative adversarial network, that reveals the complex structure of images with multiple generators in which each generator generates some part of the image. Those parts are combined by alpha blending process to create a new single image. It can generate, for example, background and face sequentially with two generators, after training on face dataset. Training was done in an unsupervised way without any labels about what each generator should generate. We found possibilities of learning the structure by using this generative model empirically.
[ { "version": "v1", "created": "Tue, 19 Jul 2016 03:09:31 GMT" }, { "version": "v2", "created": "Mon, 14 Nov 2016 07:32:35 GMT" } ]
2016-11-15T00:00:00
[ [ "Kwak", "Hanock", "" ], [ "Zhang", "Byoung-Tak", "" ] ]
TITLE: Generating Images Part by Part with Composite Generative Adversarial Networks ABSTRACT: Image generation remains a fundamental problem in artificial intelligence in general and deep learning in specific. The generative adversarial network (GAN) was successful in generating high quality samples of natural images. We propose a model called composite generative adversarial network, that reveals the complex structure of images with multiple generators in which each generator generates some part of the image. Those parts are combined by alpha blending process to create a new single image. It can generate, for example, background and face sequentially with two generators, after training on face dataset. Training was done in an unsupervised way without any labels about what each generator should generate. We found possibilities of learning the structure by using this generative model empirically.
no_new_dataset
0.950824
1608.04917
Igor Mozeti\v{c}
Darko Cherepnalkoski, Andreas Karpf, Igor Mozetic, Miha Grcar
Cohesion and Coalition Formation in the European Parliament: Roll-Call Votes and Twitter Activities
null
PLoS ONE 11(11): e0166586, 2016
10.1371/journal.pone.0166586
null
cs.CL cs.CY cs.SI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the cohesion within and the coalitions between political groups in the Eighth European Parliament (2014--2019) by analyzing two entirely different aspects of the behavior of the Members of the European Parliament (MEPs) in the policy-making processes. On one hand, we analyze their co-voting patterns and, on the other, their retweeting behavior. We make use of two diverse datasets in the analysis. The first one is the roll-call vote dataset, where cohesion is regarded as the tendency to co-vote within a group, and a coalition is formed when the members of several groups exhibit a high degree of co-voting agreement on a subject. The second dataset comes from Twitter; it captures the retweeting (i.e., endorsing) behavior of the MEPs and implies cohesion (retweets within the same group) and coalitions (retweets between groups) from a completely different perspective. We employ two different methodologies to analyze the cohesion and coalitions. The first one is based on Krippendorff's Alpha reliability, used to measure the agreement between raters in data-analysis scenarios, and the second one is based on Exponential Random Graph Models, often used in social-network analysis. We give general insights into the cohesion of political groups in the European Parliament, explore whether coalitions are formed in the same way for different policy areas, and examine to what degree the retweeting behavior of MEPs corresponds to their co-voting patterns. A novel and interesting aspect of our work is the relationship between the co-voting and retweeting patterns.
[ { "version": "v1", "created": "Wed, 17 Aug 2016 10:10:14 GMT" }, { "version": "v2", "created": "Fri, 14 Oct 2016 09:47:42 GMT" } ]
2016-11-15T00:00:00
[ [ "Cherepnalkoski", "Darko", "" ], [ "Karpf", "Andreas", "" ], [ "Mozetic", "Igor", "" ], [ "Grcar", "Miha", "" ] ]
TITLE: Cohesion and Coalition Formation in the European Parliament: Roll-Call Votes and Twitter Activities ABSTRACT: We study the cohesion within and the coalitions between political groups in the Eighth European Parliament (2014--2019) by analyzing two entirely different aspects of the behavior of the Members of the European Parliament (MEPs) in the policy-making processes. On one hand, we analyze their co-voting patterns and, on the other, their retweeting behavior. We make use of two diverse datasets in the analysis. The first one is the roll-call vote dataset, where cohesion is regarded as the tendency to co-vote within a group, and a coalition is formed when the members of several groups exhibit a high degree of co-voting agreement on a subject. The second dataset comes from Twitter; it captures the retweeting (i.e., endorsing) behavior of the MEPs and implies cohesion (retweets within the same group) and coalitions (retweets between groups) from a completely different perspective. We employ two different methodologies to analyze the cohesion and coalitions. The first one is based on Krippendorff's Alpha reliability, used to measure the agreement between raters in data-analysis scenarios, and the second one is based on Exponential Random Graph Models, often used in social-network analysis. We give general insights into the cohesion of political groups in the European Parliament, explore whether coalitions are formed in the same way for different policy areas, and examine to what degree the retweeting behavior of MEPs corresponds to their co-voting patterns. A novel and interesting aspect of our work is the relationship between the co-voting and retweeting patterns.
new_dataset
0.821617
1611.02447
Pichao Wang
Pichao Wang and Zhaoyang Li and Yonghong Hou and Wanqing Li
Action Recognition Based on Joint Trajectory Maps Using Convolutional Neural Networks
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recently, Convolutional Neural Networks (ConvNets) have shown promising performances in many computer vision tasks, especially image-based recognition. How to effectively use ConvNets for video-based recognition is still an open problem. In this paper, we propose a compact, effective yet simple method to encode spatio-temporal information carried in $3D$ skeleton sequences into multiple $2D$ images, referred to as Joint Trajectory Maps (JTM), and ConvNets are adopted to exploit the discriminative features for real-time human action recognition. The proposed method has been evaluated on three public benchmarks, i.e., MSRC-12 Kinect gesture dataset (MSRC-12), G3D dataset and UTD multimodal human action dataset (UTD-MHAD) and achieved the state-of-the-art results.
[ { "version": "v1", "created": "Tue, 8 Nov 2016 09:35:17 GMT" }, { "version": "v2", "created": "Sun, 13 Nov 2016 23:24:58 GMT" } ]
2016-11-15T00:00:00
[ [ "Wang", "Pichao", "" ], [ "Li", "Zhaoyang", "" ], [ "Hou", "Yonghong", "" ], [ "Li", "Wanqing", "" ] ]
TITLE: Action Recognition Based on Joint Trajectory Maps Using Convolutional Neural Networks ABSTRACT: Recently, Convolutional Neural Networks (ConvNets) have shown promising performances in many computer vision tasks, especially image-based recognition. How to effectively use ConvNets for video-based recognition is still an open problem. In this paper, we propose a compact, effective yet simple method to encode spatio-temporal information carried in $3D$ skeleton sequences into multiple $2D$ images, referred to as Joint Trajectory Maps (JTM), and ConvNets are adopted to exploit the discriminative features for real-time human action recognition. The proposed method has been evaluated on three public benchmarks, i.e., MSRC-12 Kinect gesture dataset (MSRC-12), G3D dataset and UTD multimodal human action dataset (UTD-MHAD) and achieved the state-of-the-art results.
no_new_dataset
0.941708
1611.03890
Guido D'Amico
Guido D'Amico, Raul Rabadan, Matthew Kleban
A Theory of Taxonomy
7+13 pages, 5 figures. Comments welcome
null
null
null
physics.soc-ph cs.SI physics.data-an q-bio.QM
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A taxonomy is a standardized framework to classify and organize items into categories. Hierarchical taxonomies are ubiquitous, ranging from the classification of organisms to the file system on a computer. Characterizing the typical distribution of items within taxonomic categories is an important question with applications in many disciplines. Ecologists have long sought to account for the patterns observed in species-abundance distributions (the number of individuals per species found in some sample), and computer scientists study the distribution of files per directory. Is there a universal statistical distribution describing how many items are typically found in each category in large taxonomies? Here, we analyze a wide array of large, real-world datasets -- including items lost and found on the New York City transit system, library books, and a bacterial microbiome -- and discover such an underlying commonality. A simple, non-parametric branching model that randomly categorizes items and takes as input only the total number of items and the total number of categories successfully reproduces the abundance distributions in these datasets. This result may shed light on patterns in species-abundance distributions long observed in ecology. The model also predicts the number of taxonomic categories that remain unrepresented in a finite sample.
[ { "version": "v1", "created": "Fri, 4 Nov 2016 19:25:49 GMT" } ]
2016-11-15T00:00:00
[ [ "D'Amico", "Guido", "" ], [ "Rabadan", "Raul", "" ], [ "Kleban", "Matthew", "" ] ]
TITLE: A Theory of Taxonomy ABSTRACT: A taxonomy is a standardized framework to classify and organize items into categories. Hierarchical taxonomies are ubiquitous, ranging from the classification of organisms to the file system on a computer. Characterizing the typical distribution of items within taxonomic categories is an important question with applications in many disciplines. Ecologists have long sought to account for the patterns observed in species-abundance distributions (the number of individuals per species found in some sample), and computer scientists study the distribution of files per directory. Is there a universal statistical distribution describing how many items are typically found in each category in large taxonomies? Here, we analyze a wide array of large, real-world datasets -- including items lost and found on the New York City transit system, library books, and a bacterial microbiome -- and discover such an underlying commonality. A simple, non-parametric branching model that randomly categorizes items and takes as input only the total number of items and the total number of categories successfully reproduces the abundance distributions in these datasets. This result may shed light on patterns in species-abundance distributions long observed in ecology. The model also predicts the number of taxonomic categories that remain unrepresented in a finite sample.
no_new_dataset
0.949856
1611.03932
Jangho Lee
Jangho Lee, Gyuwan Kim, Jaeyoon Yoo, Changwoo Jung, Minseok Kim, Sungroh Yoon
Training IBM Watson using Automatically Generated Question-Answer Pairs
null
null
null
null
cs.CL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
IBM Watson is a cognitive computing system capable of question answering in natural languages. It is believed that IBM Watson can understand large corpora and answer relevant questions more effectively than any other question-answering system currently available. To unleash the full power of Watson, however, we need to train its instance with a large number of well-prepared question-answer pairs. Obviously, manually generating such pairs in a large quantity is prohibitively time consuming and significantly limits the efficiency of Watson's training. Recently, a large-scale dataset of over 30 million question-answer pairs was reported. Under the assumption that using such an automatically generated dataset could relieve the burden of manual question-answer generation, we tried to use this dataset to train an instance of Watson and checked the training efficiency and accuracy. According to our experiments, using this auto-generated dataset was effective for training Watson, complementing manually crafted question-answer pairs. To the best of the authors' knowledge, this work is the first attempt to use a large-scale dataset of automatically generated question-answer pairs for training IBM Watson. We anticipate that the insights and lessons obtained from our experiments will be useful for researchers who want to expedite Watson training leveraged by automatically generated question-answer pairs.
[ { "version": "v1", "created": "Sat, 12 Nov 2016 01:49:48 GMT" } ]
2016-11-15T00:00:00
[ [ "Lee", "Jangho", "" ], [ "Kim", "Gyuwan", "" ], [ "Yoo", "Jaeyoon", "" ], [ "Jung", "Changwoo", "" ], [ "Kim", "Minseok", "" ], [ "Yoon", "Sungroh", "" ] ]
TITLE: Training IBM Watson using Automatically Generated Question-Answer Pairs ABSTRACT: IBM Watson is a cognitive computing system capable of question answering in natural languages. It is believed that IBM Watson can understand large corpora and answer relevant questions more effectively than any other question-answering system currently available. To unleash the full power of Watson, however, we need to train its instance with a large number of well-prepared question-answer pairs. Obviously, manually generating such pairs in a large quantity is prohibitively time consuming and significantly limits the efficiency of Watson's training. Recently, a large-scale dataset of over 30 million question-answer pairs was reported. Under the assumption that using such an automatically generated dataset could relieve the burden of manual question-answer generation, we tried to use this dataset to train an instance of Watson and checked the training efficiency and accuracy. According to our experiments, using this auto-generated dataset was effective for training Watson, complementing manually crafted question-answer pairs. To the best of the authors' knowledge, this work is the first attempt to use a large-scale dataset of automatically generated question-answer pairs for training IBM Watson. We anticipate that the insights and lessons obtained from our experiments will be useful for researchers who want to expedite Watson training leveraged by automatically generated question-answer pairs.
new_dataset
0.963746
1611.03934
Ahmed Alaa
Jinsung Yoon, Ahmed M. Alaa, Martin Cadeiras, and Mihaela van der Schaar
Personalized Donor-Recipient Matching for Organ Transplantation
null
null
null
null
cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Organ transplants can improve the life expectancy and quality of life for the recipient but carries the risk of serious post-operative complications, such as septic shock and organ rejection. The probability of a successful transplant depends in a very subtle fashion on compatibility between the donor and the recipient but current medical practice is short of domain knowledge regarding the complex nature of recipient-donor compatibility. Hence a data-driven approach for learning compatibility has the potential for significant improvements in match quality. This paper proposes a novel system (ConfidentMatch) that is trained using data from electronic health records. ConfidentMatch predicts the success of an organ transplant (in terms of the 3 year survival rates) on the basis of clinical and demographic traits of the donor and recipient. ConfidentMatch captures the heterogeneity of the donor and recipient traits by optimally dividing the feature space into clusters and constructing different optimal predictive models to each cluster. The system controls the complexity of the learned predictive model in a way that allows for assuring more granular and confident predictions for a larger number of potential recipient-donor pairs, thereby ensuring that predictions are "personalized" and tailored to individual characteristics to the finest possible granularity. Experiments conducted on the UNOS heart transplant dataset show the superiority of the prognostic value of ConfidentMatch to other competing benchmarks; ConfidentMatch can provide predictions of success with 95% confidence for 5,489 patients of a total population of 9,620 patients, which corresponds to 410 more patients than the most competitive benchmark algorithm (DeepBoost).
[ { "version": "v1", "created": "Sat, 12 Nov 2016 01:53:54 GMT" } ]
2016-11-15T00:00:00
[ [ "Yoon", "Jinsung", "" ], [ "Alaa", "Ahmed M.", "" ], [ "Cadeiras", "Martin", "" ], [ "van der Schaar", "Mihaela", "" ] ]
TITLE: Personalized Donor-Recipient Matching for Organ Transplantation ABSTRACT: Organ transplants can improve the life expectancy and quality of life for the recipient but carries the risk of serious post-operative complications, such as septic shock and organ rejection. The probability of a successful transplant depends in a very subtle fashion on compatibility between the donor and the recipient but current medical practice is short of domain knowledge regarding the complex nature of recipient-donor compatibility. Hence a data-driven approach for learning compatibility has the potential for significant improvements in match quality. This paper proposes a novel system (ConfidentMatch) that is trained using data from electronic health records. ConfidentMatch predicts the success of an organ transplant (in terms of the 3 year survival rates) on the basis of clinical and demographic traits of the donor and recipient. ConfidentMatch captures the heterogeneity of the donor and recipient traits by optimally dividing the feature space into clusters and constructing different optimal predictive models to each cluster. The system controls the complexity of the learned predictive model in a way that allows for assuring more granular and confident predictions for a larger number of potential recipient-donor pairs, thereby ensuring that predictions are "personalized" and tailored to individual characteristics to the finest possible granularity. Experiments conducted on the UNOS heart transplant dataset show the superiority of the prognostic value of ConfidentMatch to other competing benchmarks; ConfidentMatch can provide predictions of success with 95% confidence for 5,489 patients of a total population of 9,620 patients, which corresponds to 410 more patients than the most competitive benchmark algorithm (DeepBoost).
no_new_dataset
0.949106
1611.03999
David Freire-Obreg\'on
D. Freire-Obreg\'on and M. Castrill\'on-Santana and J. Lorenzo-Navarro
Optimized clothes segmentation to boost gender classification in unconstrained scenarios
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Several applications require demographic information of ordinary people in unconstrained scenarios. This is not a trivial task due to significant human appearance variations. In this work, we introduce trixels for clustering image regions, enumerating their advantages compared to superpixels. The classical GrabCut algorithm is later modified to segment trixels instead of pixels in an unsupervised context. Combining with face detection lead us to a clothes segmentation approach close to real time. The study uses the challenging Pascal VOC dataset for segmentation evaluation experiments. A final experiment analyzes the fusion of clothes features with state-of-the-art gender classifiers in ClothesDB, revealing a significant performance improvement in gender classification.
[ { "version": "v1", "created": "Sat, 12 Nov 2016 13:39:55 GMT" } ]
2016-11-15T00:00:00
[ [ "Freire-Obregón", "D.", "" ], [ "Castrillón-Santana", "M.", "" ], [ "Lorenzo-Navarro", "J.", "" ] ]
TITLE: Optimized clothes segmentation to boost gender classification in unconstrained scenarios ABSTRACT: Several applications require demographic information of ordinary people in unconstrained scenarios. This is not a trivial task due to significant human appearance variations. In this work, we introduce trixels for clustering image regions, enumerating their advantages compared to superpixels. The classical GrabCut algorithm is later modified to segment trixels instead of pixels in an unsupervised context. Combining with face detection lead us to a clothes segmentation approach close to real time. The study uses the challenging Pascal VOC dataset for segmentation evaluation experiments. A final experiment analyzes the fusion of clothes features with state-of-the-art gender classifiers in ClothesDB, revealing a significant performance improvement in gender classification.
no_new_dataset
0.953362
1611.04049
Chuyang Ke
Chuyang Ke, Yan Jin, Heather Evans, Bill Lober, Xiaoning Qian, Ji Liu, Shuai Huang
Prognostics of Surgical Site Infections using Dynamic Health Data
23 pages, 8 figures
null
null
null
cs.LG
http://creativecommons.org/licenses/by/4.0/
Surgical Site Infection (SSI) is a national priority in healthcare research. Much research attention has been attracted to develop better SSI risk prediction models. However, most of the existing SSI risk prediction models are built on static risk factors such as comorbidities and operative factors. In this paper, we investigate the use of the dynamic wound data for SSI risk prediction. There have been emerging mobile health (mHealth) tools that can closely monitor the patients and generate continuous measurements of many wound-related variables and other evolving clinical variables. Since existing prediction models of SSI have quite limited capacity to utilize the evolving clinical data, we develop the corresponding solution to equip these mHealth tools with decision-making capabilities for SSI prediction with a seamless assembly of several machine learning models to tackle the analytic challenges arising from the spatial-temporal data. The basic idea is to exploit the low-rank property of the spatial-temporal data via the bilinear formulation, and further enhance it with automatic missing data imputation by the matrix completion technique. We derive efficient optimization algorithms to implement these models and demonstrate the superior performances of our new predictive model on a real-world dataset of SSI, compared to a range of state-of-the-art methods.
[ { "version": "v1", "created": "Sat, 12 Nov 2016 22:08:15 GMT" } ]
2016-11-15T00:00:00
[ [ "Ke", "Chuyang", "" ], [ "Jin", "Yan", "" ], [ "Evans", "Heather", "" ], [ "Lober", "Bill", "" ], [ "Qian", "Xiaoning", "" ], [ "Liu", "Ji", "" ], [ "Huang", "Shuai", "" ] ]
TITLE: Prognostics of Surgical Site Infections using Dynamic Health Data ABSTRACT: Surgical Site Infection (SSI) is a national priority in healthcare research. Much research attention has been attracted to develop better SSI risk prediction models. However, most of the existing SSI risk prediction models are built on static risk factors such as comorbidities and operative factors. In this paper, we investigate the use of the dynamic wound data for SSI risk prediction. There have been emerging mobile health (mHealth) tools that can closely monitor the patients and generate continuous measurements of many wound-related variables and other evolving clinical variables. Since existing prediction models of SSI have quite limited capacity to utilize the evolving clinical data, we develop the corresponding solution to equip these mHealth tools with decision-making capabilities for SSI prediction with a seamless assembly of several machine learning models to tackle the analytic challenges arising from the spatial-temporal data. The basic idea is to exploit the low-rank property of the spatial-temporal data via the bilinear formulation, and further enhance it with automatic missing data imputation by the matrix completion technique. We derive efficient optimization algorithms to implement these models and demonstrate the superior performances of our new predictive model on a real-world dataset of SSI, compared to a range of state-of-the-art methods.
no_new_dataset
0.944638
1611.04144
Xuanpeng Li
Xuanpeng Li and Rachid Belaroussi
Semi-Dense 3D Semantic Mapping from Monocular SLAM
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The bundle of geometry and appearance in computer vision has proven to be a promising solution for robots across a wide variety of applications. Stereo cameras and RGB-D sensors are widely used to realise fast 3D reconstruction and trajectory tracking in a dense way. However, they lack flexibility of seamless switch between different scaled environments, i.e., indoor and outdoor scenes. In addition, semantic information are still hard to acquire in a 3D mapping. We address this challenge by combining the state-of-art deep learning method and semi-dense Simultaneous Localisation and Mapping (SLAM) based on video stream from a monocular camera. In our approach, 2D semantic information are transferred to 3D mapping via correspondence between connective Keyframes with spatial consistency. There is no need to obtain a semantic segmentation for each frame in a sequence, so that it could achieve a reasonable computation time. We evaluate our method on indoor/outdoor datasets and lead to an improvement in the 2D semantic labelling over baseline single frame predictions.
[ { "version": "v1", "created": "Sun, 13 Nov 2016 15:31:31 GMT" } ]
2016-11-15T00:00:00
[ [ "Li", "Xuanpeng", "" ], [ "Belaroussi", "Rachid", "" ] ]
TITLE: Semi-Dense 3D Semantic Mapping from Monocular SLAM ABSTRACT: The bundle of geometry and appearance in computer vision has proven to be a promising solution for robots across a wide variety of applications. Stereo cameras and RGB-D sensors are widely used to realise fast 3D reconstruction and trajectory tracking in a dense way. However, they lack flexibility of seamless switch between different scaled environments, i.e., indoor and outdoor scenes. In addition, semantic information are still hard to acquire in a 3D mapping. We address this challenge by combining the state-of-art deep learning method and semi-dense Simultaneous Localisation and Mapping (SLAM) based on video stream from a monocular camera. In our approach, 2D semantic information are transferred to 3D mapping via correspondence between connective Keyframes with spatial consistency. There is no need to obtain a semantic segmentation for each frame in a sequence, so that it could achieve a reasonable computation time. We evaluate our method on indoor/outdoor datasets and lead to an improvement in the 2D semantic labelling over baseline single frame predictions.
no_new_dataset
0.944638
1611.04228
Aseem Wadhwa
Aseem Wadhwa and Upamanyu Madhow
Learning Sparse, Distributed Representations using the Hebbian Principle
null
null
null
null
cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The "fire together, wire together" Hebbian model is a central principle for learning in neuroscience, but surprisingly, it has found limited applicability in modern machine learning. In this paper, we take a first step towards bridging this gap, by developing flavors of competitive Hebbian learning which produce sparse, distributed neural codes using online adaptation with minimal tuning. We propose an unsupervised algorithm, termed Adaptive Hebbian Learning (AHL). We illustrate the distributed nature of the learned representations via output entropy computations for synthetic data, and demonstrate superior performance, compared to standard alternatives such as autoencoders, in training a deep convolutional net on standard image datasets.
[ { "version": "v1", "created": "Mon, 14 Nov 2016 02:28:13 GMT" } ]
2016-11-15T00:00:00
[ [ "Wadhwa", "Aseem", "" ], [ "Madhow", "Upamanyu", "" ] ]
TITLE: Learning Sparse, Distributed Representations using the Hebbian Principle ABSTRACT: The "fire together, wire together" Hebbian model is a central principle for learning in neuroscience, but surprisingly, it has found limited applicability in modern machine learning. In this paper, we take a first step towards bridging this gap, by developing flavors of competitive Hebbian learning which produce sparse, distributed neural codes using online adaptation with minimal tuning. We propose an unsupervised algorithm, termed Adaptive Hebbian Learning (AHL). We illustrate the distributed nature of the learned representations via output entropy computations for synthetic data, and demonstrate superior performance, compared to standard alternatives such as autoencoders, in training a deep convolutional net on standard image datasets.
no_new_dataset
0.950227
1611.04298
Chengzhe Yan Mr
Chengzhe Yan, Jie Hu and Changshui Zhang
A DNN Framework For Text Image Rectification From Planar Transformations
9 pages, 10 figures
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, a novel neural network architecture is proposed attempting to rectify text images with mild assumptions. A new dataset of text images is collected to verify our model and open to public. We explored the capability of deep neural network in learning geometric transformation and found the model could segment the text image without explicit supervised segmentation information. Experiments show the architecture proposed can restore planar transformations with wonderful robustness and effectiveness.
[ { "version": "v1", "created": "Mon, 14 Nov 2016 09:40:38 GMT" } ]
2016-11-15T00:00:00
[ [ "Yan", "Chengzhe", "" ], [ "Hu", "Jie", "" ], [ "Zhang", "Changshui", "" ] ]
TITLE: A DNN Framework For Text Image Rectification From Planar Transformations ABSTRACT: In this paper, a novel neural network architecture is proposed attempting to rectify text images with mild assumptions. A new dataset of text images is collected to verify our model and open to public. We explored the capability of deep neural network in learning geometric transformation and found the model could segment the text image without explicit supervised segmentation information. Experiments show the architecture proposed can restore planar transformations with wonderful robustness and effectiveness.
new_dataset
0.956917
1611.04357
Yashas Annadani
Yashas Annadani, Vijayakrishna Naganoor, Akshay Kumar Jagadish, Krishnan Chemmangat
Selfie Detection by Synergy-Constraint Based Convolutional Neural Network
8 Pages, Accepted for Publication at IEEE SITIS 2016
null
null
null
cs.CV
http://creativecommons.org/licenses/by-nc-sa/4.0/
Categorisation of huge amount of data on the multimedia platform is a crucial task. In this work, we propose a novel approach to address the subtle problem of selfie detection for image database segregation on the web, given rapid rise in number of selfies clicked. A Convolutional Neural Network (CNN) is modeled to learn a synergy feature in the common subspace of head and shoulder orientation, derived from Local Binary Pattern (LBP) and Histogram of Oriented Gradients (HOG) features respectively. This synergy was captured by projecting the aforementioned features using Canonical Correlation Analysis (CCA). We show that the resulting network's convolutional activations in the neighbourhood of spatial keypoints captured by SIFT are discriminative for selfie-detection. In general, proposed approach aids in capturing intricacies present in the image data and has the potential for usage in other subtle image analysis scenarios apart from just selfie detection. We investigate and analyse the performance of popular CNN architectures (GoogleNet, AlexNet), used for other image classification tasks, when subjected to the task of detecting the selfies on the multimedia platform. The results of the proposed approach are compared with these popular architectures on a dataset of ninety thousand images comprising of roughly equal number of selfies and non-selfies. Experimental results on this dataset shows the effectiveness of the proposed approach.
[ { "version": "v1", "created": "Mon, 14 Nov 2016 12:22:34 GMT" } ]
2016-11-15T00:00:00
[ [ "Annadani", "Yashas", "" ], [ "Naganoor", "Vijayakrishna", "" ], [ "Jagadish", "Akshay Kumar", "" ], [ "Chemmangat", "Krishnan", "" ] ]
TITLE: Selfie Detection by Synergy-Constraint Based Convolutional Neural Network ABSTRACT: Categorisation of huge amount of data on the multimedia platform is a crucial task. In this work, we propose a novel approach to address the subtle problem of selfie detection for image database segregation on the web, given rapid rise in number of selfies clicked. A Convolutional Neural Network (CNN) is modeled to learn a synergy feature in the common subspace of head and shoulder orientation, derived from Local Binary Pattern (LBP) and Histogram of Oriented Gradients (HOG) features respectively. This synergy was captured by projecting the aforementioned features using Canonical Correlation Analysis (CCA). We show that the resulting network's convolutional activations in the neighbourhood of spatial keypoints captured by SIFT are discriminative for selfie-detection. In general, proposed approach aids in capturing intricacies present in the image data and has the potential for usage in other subtle image analysis scenarios apart from just selfie detection. We investigate and analyse the performance of popular CNN architectures (GoogleNet, AlexNet), used for other image classification tasks, when subjected to the task of detecting the selfies on the multimedia platform. The results of the proposed approach are compared with these popular architectures on a dataset of ninety thousand images comprising of roughly equal number of selfies and non-selfies. Experimental results on this dataset shows the effectiveness of the proposed approach.
no_new_dataset
0.741323
1611.04361
Marek Rei
Marek Rei, Gamal K.O. Crichton, Sampo Pyysalo
Attending to Characters in Neural Sequence Labeling Models
Proceedings of COLING 2016
null
null
null
cs.CL cs.LG cs.NE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Sequence labeling architectures use word embeddings for capturing similarity, but suffer when handling previously unseen or rare words. We investigate character-level extensions to such models and propose a novel architecture for combining alternative word representations. By using an attention mechanism, the model is able to dynamically decide how much information to use from a word- or character-level component. We evaluated different architectures on a range of sequence labeling datasets, and character-level extensions were found to improve performance on every benchmark. In addition, the proposed attention-based architecture delivered the best results even with a smaller number of trainable parameters.
[ { "version": "v1", "created": "Mon, 14 Nov 2016 12:36:07 GMT" } ]
2016-11-15T00:00:00
[ [ "Rei", "Marek", "" ], [ "Crichton", "Gamal K. O.", "" ], [ "Pyysalo", "Sampo", "" ] ]
TITLE: Attending to Characters in Neural Sequence Labeling Models ABSTRACT: Sequence labeling architectures use word embeddings for capturing similarity, but suffer when handling previously unseen or rare words. We investigate character-level extensions to such models and propose a novel architecture for combining alternative word representations. By using an attention mechanism, the model is able to dynamically decide how much information to use from a word- or character-level component. We evaluated different architectures on a range of sequence labeling datasets, and character-level extensions were found to improve performance on every benchmark. In addition, the proposed attention-based architecture delivered the best results even with a smaller number of trainable parameters.
no_new_dataset
0.952175
1611.04413
Ronan Sicre
Ronan Sicre, Julien Rabin, Yannis Avrithis, Teddy Furon, Frederic Jurie
Automatic discovery of discriminative parts as a quadratic assignment problem
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Part-based image classification consists in representing categories by small sets of discriminative parts upon which a representation of the images is built. This paper addresses the question of how to automatically learn such parts from a set of labeled training images. The training of parts is cast as a quadratic assignment problem in which optimal correspondences between image regions and parts are automatically learned. The paper analyses different assignment strategies and thoroughly evaluates them on two public datasets: Willow actions and MIT 67 scenes. State-of-the art results are obtained on these datasets.
[ { "version": "v1", "created": "Mon, 14 Nov 2016 15:17:48 GMT" } ]
2016-11-15T00:00:00
[ [ "Sicre", "Ronan", "" ], [ "Rabin", "Julien", "" ], [ "Avrithis", "Yannis", "" ], [ "Furon", "Teddy", "" ], [ "Jurie", "Frederic", "" ] ]
TITLE: Automatic discovery of discriminative parts as a quadratic assignment problem ABSTRACT: Part-based image classification consists in representing categories by small sets of discriminative parts upon which a representation of the images is built. This paper addresses the question of how to automatically learn such parts from a set of labeled training images. The training of parts is cast as a quadratic assignment problem in which optimal correspondences between image regions and parts are automatically learned. The paper analyses different assignment strategies and thoroughly evaluates them on two public datasets: Willow actions and MIT 67 scenes. State-of-the art results are obtained on these datasets.
no_new_dataset
0.952574
1611.04455
Hongyi Liu
Vaidehi Dalmia, Hongyi Liu, Shih-Fu Chang
Columbia MVSO Image Sentiment Dataset
null
null
null
null
cs.MM
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Multilingual Visual Sentiment Ontology (MVSO) consists of 15,600 concepts in 12 different languages that are strongly related to emotions and sentiments expressed in images. These concepts are defined in the form of Adjective-Noun Pair (ANP), which are crawled and discovered from online image forum Flickr. In this work, we used Amazon Mechanical Turk as a crowd-sourcing platform to collect human judgments on sentiments expressed in images that are uniformly sampled over 3,911 English ANPs extracted from a tag-restricted subset of MVSO. Our goal is to use the dataset as a benchmark for the evaluation of systems that automatically predict sentiments in images or ANPs.
[ { "version": "v1", "created": "Mon, 14 Nov 2016 16:48:12 GMT" } ]
2016-11-15T00:00:00
[ [ "Dalmia", "Vaidehi", "" ], [ "Liu", "Hongyi", "" ], [ "Chang", "Shih-Fu", "" ] ]
TITLE: Columbia MVSO Image Sentiment Dataset ABSTRACT: The Multilingual Visual Sentiment Ontology (MVSO) consists of 15,600 concepts in 12 different languages that are strongly related to emotions and sentiments expressed in images. These concepts are defined in the form of Adjective-Noun Pair (ANP), which are crawled and discovered from online image forum Flickr. In this work, we used Amazon Mechanical Turk as a crowd-sourcing platform to collect human judgments on sentiments expressed in images that are uniformly sampled over 3,911 English ANPs extracted from a tag-restricted subset of MVSO. Our goal is to use the dataset as a benchmark for the evaluation of systems that automatically predict sentiments in images or ANPs.
new_dataset
0.962568
1611.04534
Mu Zhou
Darvin Yi and Mu Zhou and Zhao Chen and Olivier Gevaert
3-D Convolutional Neural Networks for Glioblastoma Segmentation
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Convolutional Neural Networks (CNN) have emerged as powerful tools for learning discriminative image features. In this paper, we propose a framework of 3-D fully CNN models for Glioblastoma segmentation from multi-modality MRI data. By generalizing CNN models to true 3-D convolutions in learning 3-D tumor MRI data, the proposed approach utilizes a unique network architecture to decouple image pixels. Specifically, we design a convolutional layer with pre-defined Difference- of-Gaussian (DoG) filters to perform true 3-D convolution incorporating local neighborhood information at each pixel. We then use three trained convolutional layers that act to decouple voxels from the initial 3-D convolution. The proposed framework allows identification of high-level tumor structures on MRI. We evaluate segmentation performance on the BRATS segmentation dataset with 274 tumor samples. Extensive experimental results demonstrate encouraging performance of the proposed approach comparing to the state-of-the-art methods. Our data-driven approach achieves a median Dice score accuracy of 89% in whole tumor glioblastoma segmentation, revealing a generalized low-bias possibility to learn from medium-size MRI datasets.
[ { "version": "v1", "created": "Mon, 14 Nov 2016 19:21:33 GMT" } ]
2016-11-15T00:00:00
[ [ "Yi", "Darvin", "" ], [ "Zhou", "Mu", "" ], [ "Chen", "Zhao", "" ], [ "Gevaert", "Olivier", "" ] ]
TITLE: 3-D Convolutional Neural Networks for Glioblastoma Segmentation ABSTRACT: Convolutional Neural Networks (CNN) have emerged as powerful tools for learning discriminative image features. In this paper, we propose a framework of 3-D fully CNN models for Glioblastoma segmentation from multi-modality MRI data. By generalizing CNN models to true 3-D convolutions in learning 3-D tumor MRI data, the proposed approach utilizes a unique network architecture to decouple image pixels. Specifically, we design a convolutional layer with pre-defined Difference- of-Gaussian (DoG) filters to perform true 3-D convolution incorporating local neighborhood information at each pixel. We then use three trained convolutional layers that act to decouple voxels from the initial 3-D convolution. The proposed framework allows identification of high-level tumor structures on MRI. We evaluate segmentation performance on the BRATS segmentation dataset with 274 tumor samples. Extensive experimental results demonstrate encouraging performance of the proposed approach comparing to the state-of-the-art methods. Our data-driven approach achieves a median Dice score accuracy of 89% in whole tumor glioblastoma segmentation, revealing a generalized low-bias possibility to learn from medium-size MRI datasets.
no_new_dataset
0.948822
1611.04581
Peter Jin
Peter H. Jin, Qiaochu Yuan, Forrest Iandola, Kurt Keutzer
How to scale distributed deep learning?
Extended version of paper accepted at ML Sys 2016 (at NIPS 2016)
null
null
null
cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Training time on large datasets for deep neural networks is the principal workflow bottleneck in a number of important applications of deep learning, such as object classification and detection in automatic driver assistance systems (ADAS). To minimize training time, the training of a deep neural network must be scaled beyond a single machine to as many machines as possible by distributing the optimization method used for training. While a number of approaches have been proposed for distributed stochastic gradient descent (SGD), at the current time synchronous approaches to distributed SGD appear to be showing the greatest performance at large scale. Synchronous scaling of SGD suffers from the need to synchronize all processors on each gradient step and is not resilient in the face of failing or lagging processors. In asynchronous approaches using parameter servers, training is slowed by contention to the parameter server. In this paper we compare the convergence of synchronous and asynchronous SGD for training a modern ResNet network architecture on the ImageNet classification problem. We also propose an asynchronous method, gossiping SGD, that aims to retain the positive features of both systems by replacing the all-reduce collective operation of synchronous training with a gossip aggregation algorithm. We find, perhaps counterintuitively, that asynchronous SGD, including both elastic averaging and gossiping, converges faster at fewer nodes (up to about 32 nodes), whereas synchronous SGD scales better to more nodes (up to about 100 nodes).
[ { "version": "v1", "created": "Mon, 14 Nov 2016 20:59:54 GMT" } ]
2016-11-15T00:00:00
[ [ "Jin", "Peter H.", "" ], [ "Yuan", "Qiaochu", "" ], [ "Iandola", "Forrest", "" ], [ "Keutzer", "Kurt", "" ] ]
TITLE: How to scale distributed deep learning? ABSTRACT: Training time on large datasets for deep neural networks is the principal workflow bottleneck in a number of important applications of deep learning, such as object classification and detection in automatic driver assistance systems (ADAS). To minimize training time, the training of a deep neural network must be scaled beyond a single machine to as many machines as possible by distributing the optimization method used for training. While a number of approaches have been proposed for distributed stochastic gradient descent (SGD), at the current time synchronous approaches to distributed SGD appear to be showing the greatest performance at large scale. Synchronous scaling of SGD suffers from the need to synchronize all processors on each gradient step and is not resilient in the face of failing or lagging processors. In asynchronous approaches using parameter servers, training is slowed by contention to the parameter server. In this paper we compare the convergence of synchronous and asynchronous SGD for training a modern ResNet network architecture on the ImageNet classification problem. We also propose an asynchronous method, gossiping SGD, that aims to retain the positive features of both systems by replacing the all-reduce collective operation of synchronous training with a gossip aggregation algorithm. We find, perhaps counterintuitively, that asynchronous SGD, including both elastic averaging and gossiping, converges faster at fewer nodes (up to about 32 nodes), whereas synchronous SGD scales better to more nodes (up to about 100 nodes).
no_new_dataset
0.943867
physics/0412112
Jeanine Pellet
D. Lazaro, Z. El Bitar (LPC-Clermont), V. Breton (LPC-Clermont), I. Buvat
Effect of noise and modeling errors on the reliability of fully 3D Monte Carlo reconstruction in SPECT
null
Dans Proceedings (2004) 1-4 - Conference: IEEE Nuclear Science Symposium And Medical Imaging Conference (NSS / MIC) (2004-10-16 to 2004-10-22), Rome (it)
10.1109/NSSMIC.2004.1462770
null
physics.med-ph
null
We recently demonstrated the value of reconstructing SPECT data with fully 3D Monte Carlo reconstruction (F3DMC), in terms of spatial resolution and quantification. This was shown on a small cubic phantom (64 projections 10 x 10) in some idealistic configurations. The goals of the present study were to assess the effect of noise and modeling errors on the reliability of F3DMC, to propose and evaluate strategies for reducing the noise in the projector, and to demonstrate the feasibility of F3DMC for a dataset with realistic dimensions. A small cubic phantom and a realistic Jaszczak phantom dataset were considered. Projections and projectors for both phantoms were calculated using the Monte Carlo simulation code GATE. Projectors with different statistics were considered and two methods for reducing noise in the projector were investigated: one based on principal component analysis (PCA) and the other consisting in setting small probability values to zero. Energy and spatial shifts in projection sampling with respect to projector sampling were also introduced to test F3DMC in realistic conditions. Experiments with the cubic phantom showed the importance of using simulations with high statistics for calculating the projector, and the value of filtering the projector using a PCA approach. F3DMC was shown to be robust with respect to energy shift and small spatial sampling off-set between the projector and the projections. Images of the Jaszczak phantom were successfully reconstructed and also showed promising results in terms of spatial resolution recovery and quantitative accuracy in small structures. It is concluded that the promising results of F3DMC hold on realistic data sets
[ { "version": "v1", "created": "Fri, 17 Dec 2004 14:49:10 GMT" } ]
2016-11-15T00:00:00
[ [ "Lazaro", "D.", "", "LPC-Clermont" ], [ "Bitar", "Z. El", "", "LPC-Clermont" ], [ "Breton", "V.", "", "LPC-Clermont" ], [ "Buvat", "I.", "" ] ]
TITLE: Effect of noise and modeling errors on the reliability of fully 3D Monte Carlo reconstruction in SPECT ABSTRACT: We recently demonstrated the value of reconstructing SPECT data with fully 3D Monte Carlo reconstruction (F3DMC), in terms of spatial resolution and quantification. This was shown on a small cubic phantom (64 projections 10 x 10) in some idealistic configurations. The goals of the present study were to assess the effect of noise and modeling errors on the reliability of F3DMC, to propose and evaluate strategies for reducing the noise in the projector, and to demonstrate the feasibility of F3DMC for a dataset with realistic dimensions. A small cubic phantom and a realistic Jaszczak phantom dataset were considered. Projections and projectors for both phantoms were calculated using the Monte Carlo simulation code GATE. Projectors with different statistics were considered and two methods for reducing noise in the projector were investigated: one based on principal component analysis (PCA) and the other consisting in setting small probability values to zero. Energy and spatial shifts in projection sampling with respect to projector sampling were also introduced to test F3DMC in realistic conditions. Experiments with the cubic phantom showed the importance of using simulations with high statistics for calculating the projector, and the value of filtering the projector using a PCA approach. F3DMC was shown to be robust with respect to energy shift and small spatial sampling off-set between the projector and the projections. Images of the Jaszczak phantom were successfully reconstructed and also showed promising results in terms of spatial resolution recovery and quantitative accuracy in small structures. It is concluded that the promising results of F3DMC hold on realistic data sets
no_new_dataset
0.950227
1508.04924
Hamid Palangi
Hamid Palangi, Rabab Ward, Li Deng
Distributed Compressive Sensing: A Deep Learning Approach
To appear in IEEE Transactions on Signal Processing
IEEE Transactions on Signal Processing, Volume: 64, Issue: 17, pp. 4504-4518, 2016
10.1109/TSP.2016.2557301
null
cs.LG cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Various studies that address the compressed sensing problem with Multiple Measurement Vectors (MMVs) have been recently carried. These studies assume the vectors of the different channels to be jointly sparse. In this paper, we relax this condition. Instead we assume that these sparse vectors depend on each other but that this dependency is unknown. We capture this dependency by computing the conditional probability of each entry in each vector being non-zero, given the "residuals" of all previous vectors. To estimate these probabilities, we propose the use of the Long Short-Term Memory (LSTM)[1], a data driven model for sequence modelling that is deep in time. To calculate the model parameters, we minimize a cross entropy cost function. To reconstruct the sparse vectors at the decoder, we propose a greedy solver that uses the above model to estimate the conditional probabilities. By performing extensive experiments on two real world datasets, we show that the proposed method significantly outperforms the general MMV solver (the Simultaneous Orthogonal Matching Pursuit (SOMP)) and a number of the model-based Bayesian methods. The proposed method does not add any complexity to the general compressive sensing encoder. The trained model is used just at the decoder. As the proposed method is a data driven method, it is only applicable when training data is available. In many applications however, training data is indeed available, e.g. in recorded images and videos.
[ { "version": "v1", "created": "Thu, 20 Aug 2015 08:57:29 GMT" }, { "version": "v2", "created": "Mon, 7 Sep 2015 01:15:11 GMT" }, { "version": "v3", "created": "Wed, 11 May 2016 22:18:13 GMT" } ]
2016-11-14T00:00:00
[ [ "Palangi", "Hamid", "" ], [ "Ward", "Rabab", "" ], [ "Deng", "Li", "" ] ]
TITLE: Distributed Compressive Sensing: A Deep Learning Approach ABSTRACT: Various studies that address the compressed sensing problem with Multiple Measurement Vectors (MMVs) have been recently carried. These studies assume the vectors of the different channels to be jointly sparse. In this paper, we relax this condition. Instead we assume that these sparse vectors depend on each other but that this dependency is unknown. We capture this dependency by computing the conditional probability of each entry in each vector being non-zero, given the "residuals" of all previous vectors. To estimate these probabilities, we propose the use of the Long Short-Term Memory (LSTM)[1], a data driven model for sequence modelling that is deep in time. To calculate the model parameters, we minimize a cross entropy cost function. To reconstruct the sparse vectors at the decoder, we propose a greedy solver that uses the above model to estimate the conditional probabilities. By performing extensive experiments on two real world datasets, we show that the proposed method significantly outperforms the general MMV solver (the Simultaneous Orthogonal Matching Pursuit (SOMP)) and a number of the model-based Bayesian methods. The proposed method does not add any complexity to the general compressive sensing encoder. The trained model is used just at the decoder. As the proposed method is a data driven method, it is only applicable when training data is available. In many applications however, training data is indeed available, e.g. in recorded images and videos.
no_new_dataset
0.944638
1510.04130
Jaroslav Fowkes
Jaroslav Fowkes and Charles Sutton
A Bayesian Network Model for Interesting Itemsets
Supplementary material attached as Ancillary File; in PKDD 2016: European Conference on Machine Learning and Knowledge Discovery in Databases
null
10.1007/978-3-319-46227-1_26
null
stat.ML cs.DB cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Mining itemsets that are the most interesting under a statistical model of the underlying data is a commonly used and well-studied technique for exploratory data analysis, with the most recent interestingness models exhibiting state of the art performance. Continuing this highly promising line of work, we propose the first, to the best of our knowledge, generative model over itemsets, in the form of a Bayesian network, and an associated novel measure of interestingness. Our model is able to efficiently infer interesting itemsets directly from the transaction database using structural EM, in which the E-step employs the greedy approximation to weighted set cover. Our approach is theoretically simple, straightforward to implement, trivially parallelizable and retrieves itemsets whose quality is comparable to, if not better than, existing state of the art algorithms as we demonstrate on several real-world datasets.
[ { "version": "v1", "created": "Wed, 14 Oct 2015 14:55:17 GMT" }, { "version": "v2", "created": "Fri, 11 Nov 2016 11:15:30 GMT" } ]
2016-11-14T00:00:00
[ [ "Fowkes", "Jaroslav", "" ], [ "Sutton", "Charles", "" ] ]
TITLE: A Bayesian Network Model for Interesting Itemsets ABSTRACT: Mining itemsets that are the most interesting under a statistical model of the underlying data is a commonly used and well-studied technique for exploratory data analysis, with the most recent interestingness models exhibiting state of the art performance. Continuing this highly promising line of work, we propose the first, to the best of our knowledge, generative model over itemsets, in the form of a Bayesian network, and an associated novel measure of interestingness. Our model is able to efficiently infer interesting itemsets directly from the transaction database using structural EM, in which the E-step employs the greedy approximation to weighted set cover. Our approach is theoretically simple, straightforward to implement, trivially parallelizable and retrieves itemsets whose quality is comparable to, if not better than, existing state of the art algorithms as we demonstrate on several real-world datasets.
no_new_dataset
0.950732
1602.05012
Jaroslav Fowkes
Jaroslav Fowkes and Charles Sutton
A Subsequence Interleaving Model for Sequential Pattern Mining
10 pages in KDD 2016: Proceedings of the 22nd ACM SIGKDD International Conference on Knowledge Discovery and Data Mining
null
10.1145/2939672.2939787
null
stat.ML cs.AI cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recent sequential pattern mining methods have used the minimum description length (MDL) principle to define an encoding scheme which describes an algorithm for mining the most compressing patterns in a database. We present a novel subsequence interleaving model based on a probabilistic model of the sequence database, which allows us to search for the most compressing set of patterns without designing a specific encoding scheme. Our proposed algorithm is able to efficiently mine the most relevant sequential patterns and rank them using an associated measure of interestingness. The efficient inference in our model is a direct result of our use of a structural expectation-maximization framework, in which the expectation-step takes the form of a submodular optimization problem subject to a coverage constraint. We show on both synthetic and real world datasets that our model mines a set of sequential patterns with low spuriousness and redundancy, high interpretability and usefulness in real-world applications. Furthermore, we demonstrate that the quality of the patterns from our approach is comparable to, if not better than, existing state of the art sequential pattern mining algorithms.
[ { "version": "v1", "created": "Tue, 16 Feb 2016 13:30:10 GMT" }, { "version": "v2", "created": "Fri, 11 Nov 2016 10:43:36 GMT" } ]
2016-11-14T00:00:00
[ [ "Fowkes", "Jaroslav", "" ], [ "Sutton", "Charles", "" ] ]
TITLE: A Subsequence Interleaving Model for Sequential Pattern Mining ABSTRACT: Recent sequential pattern mining methods have used the minimum description length (MDL) principle to define an encoding scheme which describes an algorithm for mining the most compressing patterns in a database. We present a novel subsequence interleaving model based on a probabilistic model of the sequence database, which allows us to search for the most compressing set of patterns without designing a specific encoding scheme. Our proposed algorithm is able to efficiently mine the most relevant sequential patterns and rank them using an associated measure of interestingness. The efficient inference in our model is a direct result of our use of a structural expectation-maximization framework, in which the expectation-step takes the form of a submodular optimization problem subject to a coverage constraint. We show on both synthetic and real world datasets that our model mines a set of sequential patterns with low spuriousness and redundancy, high interpretability and usefulness in real-world applications. Furthermore, we demonstrate that the quality of the patterns from our approach is comparable to, if not better than, existing state of the art sequential pattern mining algorithms.
no_new_dataset
0.948537
1605.03804
Sandra Avila
Carlos Caetano and Sandra Avila and William Robson Schwartz and Silvio Jamil F. Guimar\~aes and Arnaldo de A. Ara\'ujo
A Mid-level Video Representation based on Binary Descriptors: A Case Study for Pornography Detection
Manuscript accepted at Elsevier Neurocomputing
null
10.1016/j.neucom.2016.03.099
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
With the growing amount of inappropriate content on the Internet, such as pornography, arises the need to detect and filter such material. The reason for this is given by the fact that such content is often prohibited in certain environments (e.g., schools and workplaces) or for certain publics (e.g., children). In recent years, many works have been mainly focused on detecting pornographic images and videos based on visual content, particularly on the detection of skin color. Although these approaches provide good results, they generally have the disadvantage of a high false positive rate since not all images with large areas of skin exposure are necessarily pornographic images, such as people wearing swimsuits or images related to sports. Local feature based approaches with Bag-of-Words models (BoW) have been successfully applied to visual recognition tasks in the context of pornography detection. Even though existing methods provide promising results, they use local feature descriptors that require a high computational processing time yielding high-dimensional vectors. In this work, we propose an approach for pornography detection based on local binary feature extraction and BossaNova image representation, a BoW model extension that preserves more richly the visual information. Moreover, we propose two approaches for video description based on the combination of mid-level representations namely BossaNova Video Descriptor (BNVD) and BoW Video Descriptor (BoW-VD). The proposed techniques are promising, achieving an accuracy of 92.40%, thus reducing the classification error by 16% over the current state-of-the-art local features approach on the Pornography dataset.
[ { "version": "v1", "created": "Thu, 12 May 2016 13:27:12 GMT" } ]
2016-11-14T00:00:00
[ [ "Caetano", "Carlos", "" ], [ "Avila", "Sandra", "" ], [ "Schwartz", "William Robson", "" ], [ "Guimarães", "Silvio Jamil F.", "" ], [ "Araújo", "Arnaldo de A.", "" ] ]
TITLE: A Mid-level Video Representation based on Binary Descriptors: A Case Study for Pornography Detection ABSTRACT: With the growing amount of inappropriate content on the Internet, such as pornography, arises the need to detect and filter such material. The reason for this is given by the fact that such content is often prohibited in certain environments (e.g., schools and workplaces) or for certain publics (e.g., children). In recent years, many works have been mainly focused on detecting pornographic images and videos based on visual content, particularly on the detection of skin color. Although these approaches provide good results, they generally have the disadvantage of a high false positive rate since not all images with large areas of skin exposure are necessarily pornographic images, such as people wearing swimsuits or images related to sports. Local feature based approaches with Bag-of-Words models (BoW) have been successfully applied to visual recognition tasks in the context of pornography detection. Even though existing methods provide promising results, they use local feature descriptors that require a high computational processing time yielding high-dimensional vectors. In this work, we propose an approach for pornography detection based on local binary feature extraction and BossaNova image representation, a BoW model extension that preserves more richly the visual information. Moreover, we propose two approaches for video description based on the combination of mid-level representations namely BossaNova Video Descriptor (BNVD) and BoW Video Descriptor (BoW-VD). The proposed techniques are promising, achieving an accuracy of 92.40%, thus reducing the classification error by 16% over the current state-of-the-art local features approach on the Pornography dataset.
no_new_dataset
0.953535
1610.05712
Mariano Tepper
Mariano Tepper and Guillermo Sapiro
Fast L1-NMF for Multiple Parametric Model Estimation
null
null
null
null
cs.CV cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work we introduce a comprehensive algorithmic pipeline for multiple parametric model estimation. The proposed approach analyzes the information produced by a random sampling algorithm (e.g., RANSAC) from a machine learning/optimization perspective, using a \textit{parameterless} biclustering algorithm based on L1 nonnegative matrix factorization (L1-NMF). The proposed framework exploits consistent patterns that naturally arise during the RANSAC execution, while explicitly avoiding spurious inconsistencies. Contrarily to the main trends in the literature, the proposed technique does not impose non-intersecting parametric models. A new accelerated algorithm to compute L1-NMFs allows to handle medium-sized problems faster while also extending the usability of the algorithm to much larger datasets. This accelerated algorithm has applications in any other context where an L1-NMF is needed, beyond the biclustering approach to parameter estimation here addressed. We accompany the algorithmic presentation with theoretical foundations and numerous and diverse examples.
[ { "version": "v1", "created": "Tue, 18 Oct 2016 17:20:38 GMT" }, { "version": "v2", "created": "Fri, 11 Nov 2016 15:54:14 GMT" } ]
2016-11-14T00:00:00
[ [ "Tepper", "Mariano", "" ], [ "Sapiro", "Guillermo", "" ] ]
TITLE: Fast L1-NMF for Multiple Parametric Model Estimation ABSTRACT: In this work we introduce a comprehensive algorithmic pipeline for multiple parametric model estimation. The proposed approach analyzes the information produced by a random sampling algorithm (e.g., RANSAC) from a machine learning/optimization perspective, using a \textit{parameterless} biclustering algorithm based on L1 nonnegative matrix factorization (L1-NMF). The proposed framework exploits consistent patterns that naturally arise during the RANSAC execution, while explicitly avoiding spurious inconsistencies. Contrarily to the main trends in the literature, the proposed technique does not impose non-intersecting parametric models. A new accelerated algorithm to compute L1-NMFs allows to handle medium-sized problems faster while also extending the usability of the algorithm to much larger datasets. This accelerated algorithm has applications in any other context where an L1-NMF is needed, beyond the biclustering approach to parameter estimation here addressed. We accompany the algorithmic presentation with theoretical foundations and numerous and diverse examples.
no_new_dataset
0.945651
1611.01911
Ponnurangam Kumaraguru
Hemank Lamba, Varun Bharadhwaj, Mayank Vachher, Divyansh Agarwal, Megha Arora, Ponnurangam Kumaraguru
Me, Myself and My Killfie: Characterizing and Preventing Selfie Deaths
null
null
null
null
cs.SI cs.CY
http://creativecommons.org/licenses/by-nc-sa/4.0/
Over the past couple of years, clicking and posting selfies has become a popular trend. However, since March 2014, 127 people have died and many have been injured while trying to click a selfie. Researchers have studied selfies for understanding the psychology of the authors, and understanding its effect on social media platforms. In this work, we perform a comprehensive analysis of the selfie-related casualties and infer various reasons behind these deaths. We use inferences from incidents and from our understanding of the features, we create a system to make people more aware of the dangerous situations in which these selfies are taken. We use a combination of text-based, image-based and location-based features to classify a particular selfie as dangerous or not. Our method ran on 3,155 annotated selfies collected on Twitter gave 73% accuracy. Individually the image-based features were the most informative for the prediction task. The combination of image-based and location-based features resulted in the best accuracy. We have made our code and dataset available at http://labs.precog.iiitd.edu.in/killfie.
[ { "version": "v1", "created": "Mon, 7 Nov 2016 06:52:26 GMT" }, { "version": "v2", "created": "Fri, 11 Nov 2016 10:05:12 GMT" } ]
2016-11-14T00:00:00
[ [ "Lamba", "Hemank", "" ], [ "Bharadhwaj", "Varun", "" ], [ "Vachher", "Mayank", "" ], [ "Agarwal", "Divyansh", "" ], [ "Arora", "Megha", "" ], [ "Kumaraguru", "Ponnurangam", "" ] ]
TITLE: Me, Myself and My Killfie: Characterizing and Preventing Selfie Deaths ABSTRACT: Over the past couple of years, clicking and posting selfies has become a popular trend. However, since March 2014, 127 people have died and many have been injured while trying to click a selfie. Researchers have studied selfies for understanding the psychology of the authors, and understanding its effect on social media platforms. In this work, we perform a comprehensive analysis of the selfie-related casualties and infer various reasons behind these deaths. We use inferences from incidents and from our understanding of the features, we create a system to make people more aware of the dangerous situations in which these selfies are taken. We use a combination of text-based, image-based and location-based features to classify a particular selfie as dangerous or not. Our method ran on 3,155 annotated selfies collected on Twitter gave 73% accuracy. Individually the image-based features were the most informative for the prediction task. The combination of image-based and location-based features resulted in the best accuracy. We have made our code and dataset available at http://labs.precog.iiitd.edu.in/killfie.
new_dataset
0.963506
1611.03578
Guangxi Li
Guangxi Li, Zenglin Xu, Linnan Wang, Jinmian Ye, Irwin King, Michael Lyu
Simple and Efficient Parallelization for Probabilistic Temporal Tensor Factorization
null
null
null
null
stat.ML cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Probabilistic Temporal Tensor Factorization (PTTF) is an effective algorithm to model the temporal tensor data. It leverages a time constraint to capture the evolving properties of tensor data. Nowadays the exploding dataset demands a large scale PTTF analysis, and a parallel solution is critical to accommodate the trend. Whereas, the parallelization of PTTF still remains unexplored. In this paper, we propose a simple yet efficient Parallel Probabilistic Temporal Tensor Factorization, referred to as P$^2$T$^2$F, to provide a scalable PTTF solution. P$^2$T$^2$F is fundamentally disparate from existing parallel tensor factorizations by considering the probabilistic decomposition and the temporal effects of tensor data. It adopts a new tensor data split strategy to subdivide a large tensor into independent sub-tensors, the computation of which is inherently parallel. We train P$^2$T$^2$F with an efficient algorithm of stochastic Alternating Direction Method of Multipliers, and show that the convergence is guaranteed. Experiments on several real-word tensor datasets demonstrate that P$^2$T$^2$F is a highly effective and efficiently scalable algorithm dedicated for large scale probabilistic temporal tensor analysis.
[ { "version": "v1", "created": "Fri, 11 Nov 2016 03:54:00 GMT" } ]
2016-11-14T00:00:00
[ [ "Li", "Guangxi", "" ], [ "Xu", "Zenglin", "" ], [ "Wang", "Linnan", "" ], [ "Ye", "Jinmian", "" ], [ "King", "Irwin", "" ], [ "Lyu", "Michael", "" ] ]
TITLE: Simple and Efficient Parallelization for Probabilistic Temporal Tensor Factorization ABSTRACT: Probabilistic Temporal Tensor Factorization (PTTF) is an effective algorithm to model the temporal tensor data. It leverages a time constraint to capture the evolving properties of tensor data. Nowadays the exploding dataset demands a large scale PTTF analysis, and a parallel solution is critical to accommodate the trend. Whereas, the parallelization of PTTF still remains unexplored. In this paper, we propose a simple yet efficient Parallel Probabilistic Temporal Tensor Factorization, referred to as P$^2$T$^2$F, to provide a scalable PTTF solution. P$^2$T$^2$F is fundamentally disparate from existing parallel tensor factorizations by considering the probabilistic decomposition and the temporal effects of tensor data. It adopts a new tensor data split strategy to subdivide a large tensor into independent sub-tensors, the computation of which is inherently parallel. We train P$^2$T$^2$F with an efficient algorithm of stochastic Alternating Direction Method of Multipliers, and show that the convergence is guaranteed. Experiments on several real-word tensor datasets demonstrate that P$^2$T$^2$F is a highly effective and efficiently scalable algorithm dedicated for large scale probabilistic temporal tensor analysis.
no_new_dataset
0.946547
1611.03591
Renlong Hang
Qingshan Liu, Renlong Hang, Huihui Song, Zhi Li
Learning Multi-Scale Deep Features for High-Resolution Satellite Image Classification
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we propose a multi-scale deep feature learning method for high-resolution satellite image classification. Specifically, we firstly warp the original satellite image into multiple different scales. The images in each scale are employed to train a deep convolutional neural network (DCNN). However, simultaneously training multiple DCNNs is time-consuming. To address this issue, we explore DCNN with spatial pyramid pooling (SPP-net). Since different SPP-nets have the same number of parameters, which share the identical initial values, and only fine-tuning the parameters in fully-connected layers ensures the effectiveness of each network, thereby greatly accelerating the training process. Then, the multi-scale satellite images are fed into their corresponding SPP-nets respectively to extract multi-scale deep features. Finally, a multiple kernel learning method is developed to automatically learn the optimal combination of such features. Experiments on two difficult datasets show that the proposed method achieves favorable performance compared to other state-of-the-art methods.
[ { "version": "v1", "created": "Fri, 11 Nov 2016 05:31:42 GMT" } ]
2016-11-14T00:00:00
[ [ "Liu", "Qingshan", "" ], [ "Hang", "Renlong", "" ], [ "Song", "Huihui", "" ], [ "Li", "Zhi", "" ] ]
TITLE: Learning Multi-Scale Deep Features for High-Resolution Satellite Image Classification ABSTRACT: In this paper, we propose a multi-scale deep feature learning method for high-resolution satellite image classification. Specifically, we firstly warp the original satellite image into multiple different scales. The images in each scale are employed to train a deep convolutional neural network (DCNN). However, simultaneously training multiple DCNNs is time-consuming. To address this issue, we explore DCNN with spatial pyramid pooling (SPP-net). Since different SPP-nets have the same number of parameters, which share the identical initial values, and only fine-tuning the parameters in fully-connected layers ensures the effectiveness of each network, thereby greatly accelerating the training process. Then, the multi-scale satellite images are fed into their corresponding SPP-nets respectively to extract multi-scale deep features. Finally, a multiple kernel learning method is developed to automatically learn the optimal combination of such features. Experiments on two difficult datasets show that the proposed method achieves favorable performance compared to other state-of-the-art methods.
no_new_dataset
0.945951
1611.03607
Masaya Inoue
Masaya Inoue, Sozo Inoue, Takeshi Nishida
Deep Recurrent Neural Network for Mobile Human Activity Recognition with High Throughput
10 pages, 13 figures
null
null
null
cs.CV cs.NE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we propose a method of human activity recognition with high throughput from raw accelerometer data applying a deep recurrent neural network (DRNN), and investigate various architectures and its combination to find the best parameter values. The "high throughput" refers to short time at a time of recognition. We investigated various parameters and architectures of the DRNN by using the training dataset of 432 trials with 6 activity classes from 7 people. The maximum recognition rate was 95.42% and 83.43% against the test data of 108 segmented trials each of which has single activity class and 18 multiple sequential trials, respectively. Here, the maximum recognition rates by traditional methods were 71.65% and 54.97% for each. In addition, the efficiency of the found parameters was evaluated by using additional dataset. Further, as for throughput of the recognition per unit time, the constructed DRNN was requiring only 1.347 [ms], while the best traditional method required 11.031 [ms] which includes 11.027 [ms] for feature calculation. These advantages are caused by the compact and small architecture of the constructed real time oriented DRNN.
[ { "version": "v1", "created": "Fri, 11 Nov 2016 08:21:09 GMT" } ]
2016-11-14T00:00:00
[ [ "Inoue", "Masaya", "" ], [ "Inoue", "Sozo", "" ], [ "Nishida", "Takeshi", "" ] ]
TITLE: Deep Recurrent Neural Network for Mobile Human Activity Recognition with High Throughput ABSTRACT: In this paper, we propose a method of human activity recognition with high throughput from raw accelerometer data applying a deep recurrent neural network (DRNN), and investigate various architectures and its combination to find the best parameter values. The "high throughput" refers to short time at a time of recognition. We investigated various parameters and architectures of the DRNN by using the training dataset of 432 trials with 6 activity classes from 7 people. The maximum recognition rate was 95.42% and 83.43% against the test data of 108 segmented trials each of which has single activity class and 18 multiple sequential trials, respectively. Here, the maximum recognition rates by traditional methods were 71.65% and 54.97% for each. In addition, the efficiency of the found parameters was evaluated by using additional dataset. Further, as for throughput of the recognition per unit time, the constructed DRNN was requiring only 1.347 [ms], while the best traditional method required 11.031 [ms] which includes 11.027 [ms] for feature calculation. These advantages are caused by the compact and small architecture of the constructed real time oriented DRNN.
no_new_dataset
0.946349
1611.03608
Xiatian Zhang
Xiatian Zhang, Fan Yao, Yongjun Tian
Greedy Step Averaging: A parameter-free stochastic optimization method
23 pages, 24 figures
null
null
null
cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we present the greedy step averaging(GSA) method, a parameter-free stochastic optimization algorithm for a variety of machine learning problems. As a gradient-based optimization method, GSA makes use of the information from the minimizer of a single sample's loss function, and takes average strategy to calculate reasonable learning rate sequence. While most existing gradient-based algorithms introduce an increasing number of hyper parameters or try to make a trade-off between computational cost and convergence rate, GSA avoids the manual tuning of learning rate and brings in no more hyper parameters or extra cost. We perform exhaustive numerical experiments for logistic and softmax regression to compare our method with the other state of the art ones on 16 datasets. Results show that GSA is robust on various scenarios.
[ { "version": "v1", "created": "Fri, 11 Nov 2016 08:23:30 GMT" } ]
2016-11-14T00:00:00
[ [ "Zhang", "Xiatian", "" ], [ "Yao", "Fan", "" ], [ "Tian", "Yongjun", "" ] ]
TITLE: Greedy Step Averaging: A parameter-free stochastic optimization method ABSTRACT: In this paper we present the greedy step averaging(GSA) method, a parameter-free stochastic optimization algorithm for a variety of machine learning problems. As a gradient-based optimization method, GSA makes use of the information from the minimizer of a single sample's loss function, and takes average strategy to calculate reasonable learning rate sequence. While most existing gradient-based algorithms introduce an increasing number of hyper parameters or try to make a trade-off between computational cost and convergence rate, GSA avoids the manual tuning of learning rate and brings in no more hyper parameters or extra cost. We perform exhaustive numerical experiments for logistic and softmax regression to compare our method with the other state of the art ones on 16 datasets. Results show that GSA is robust on various scenarios.
no_new_dataset
0.946448
1611.03777
Barak Pearlmutter
At{\i}l{\i}m G\"une\c{s} Baydin and Barak A. Pearlmutter and Jeffrey Mark Siskind
Tricks from Deep Learning
Extended abstract presented at the AD 2016 Conference, Sep 2016, Oxford UK
null
null
null
cs.LG stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The deep learning community has devised a diverse set of methods to make gradient optimization, using large datasets, of large and highly complex models with deeply cascaded nonlinearities, practical. Taken as a whole, these methods constitute a breakthrough, allowing computational structures which are quite wide, very deep, and with an enormous number and variety of free parameters to be effectively optimized. The result now dominates much of practical machine learning, with applications in machine translation, computer vision, and speech recognition. Many of these methods, viewed through the lens of algorithmic differentiation (AD), can be seen as either addressing issues with the gradient itself, or finding ways of achieving increased efficiency using tricks that are AD-related, but not provided by current AD systems. The goal of this paper is to explain not just those methods of most relevance to AD, but also the technical constraints and mindset which led to their discovery. After explaining this context, we present a "laundry list" of methods developed by the deep learning community. Two of these are discussed in further mathematical detail: a way to dramatically reduce the size of the tape when performing reverse-mode AD on a (theoretically) time-reversible process like an ODE integrator; and a new mathematical insight that allows for the implementation of a stochastic Newton's method.
[ { "version": "v1", "created": "Thu, 10 Nov 2016 17:57:19 GMT" } ]
2016-11-14T00:00:00
[ [ "Baydin", "Atılım Güneş", "" ], [ "Pearlmutter", "Barak A.", "" ], [ "Siskind", "Jeffrey Mark", "" ] ]
TITLE: Tricks from Deep Learning ABSTRACT: The deep learning community has devised a diverse set of methods to make gradient optimization, using large datasets, of large and highly complex models with deeply cascaded nonlinearities, practical. Taken as a whole, these methods constitute a breakthrough, allowing computational structures which are quite wide, very deep, and with an enormous number and variety of free parameters to be effectively optimized. The result now dominates much of practical machine learning, with applications in machine translation, computer vision, and speech recognition. Many of these methods, viewed through the lens of algorithmic differentiation (AD), can be seen as either addressing issues with the gradient itself, or finding ways of achieving increased efficiency using tricks that are AD-related, but not provided by current AD systems. The goal of this paper is to explain not just those methods of most relevance to AD, but also the technical constraints and mindset which led to their discovery. After explaining this context, we present a "laundry list" of methods developed by the deep learning community. Two of these are discussed in further mathematical detail: a way to dramatically reduce the size of the tape when performing reverse-mode AD on a (theoretically) time-reversible process like an ODE integrator; and a new mathematical insight that allows for the implementation of a stochastic Newton's method.
no_new_dataset
0.910187
1502.02454
Thuc Le Ph.D
Thuc Duy Le, Tao Hoang, Jiuyong Li, Lin Liu, and Huawen Liu
A fast PC algorithm for high dimensional causal discovery with multi-core PCs
Thuc Le, Tao Hoang, Jiuyong Li, Lin Liu, Huawen Liu, Shu Hu, "A fast PC algorithm for high dimensional causal discovery with multi-core PCs", IEEE/ACM Transactions on Computational Biology and Bioinformatics, doi:10.1109/TCBB.2016.2591526
null
10.1109/TCBB.2016.2591526
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Discovering causal relationships from observational data is a crucial problem and it has applications in many research areas. The PC algorithm is the state-of-the-art constraint based method for causal discovery. However, runtime of the PC algorithm, in the worst-case, is exponential to the number of nodes (variables), and thus it is inefficient when being applied to high dimensional data, e.g. gene expression datasets. On another note, the advancement of computer hardware in the last decade has resulted in the widespread availability of multi-core personal computers. There is a significant motivation for designing a parallelised PC algorithm that is suitable for personal computers and does not require end users' parallel computing knowledge beyond their competency in using the PC algorithm. In this paper, we develop parallel-PC, a fast and memory efficient PC algorithm using the parallel computing technique. We apply our method to a range of synthetic and real-world high dimensional datasets. Experimental results on a dataset from the DREAM 5 challenge show that the original PC algorithm could not produce any results after running more than 24 hours; meanwhile, our parallel-PC algorithm managed to finish within around 12 hours with a 4-core CPU computer, and less than 6 hours with a 8-core CPU computer. Furthermore, we integrate parallel-PC into a causal inference method for inferring miRNA-mRNA regulatory relationships. The experimental results show that parallel-PC helps improve both the efficiency and accuracy of the causal inference algorithm.
[ { "version": "v1", "created": "Mon, 9 Feb 2015 12:15:21 GMT" }, { "version": "v2", "created": "Sat, 11 Jul 2015 03:03:16 GMT" }, { "version": "v3", "created": "Thu, 10 Nov 2016 12:23:48 GMT" } ]
2016-11-11T00:00:00
[ [ "Le", "Thuc Duy", "" ], [ "Hoang", "Tao", "" ], [ "Li", "Jiuyong", "" ], [ "Liu", "Lin", "" ], [ "Liu", "Huawen", "" ] ]
TITLE: A fast PC algorithm for high dimensional causal discovery with multi-core PCs ABSTRACT: Discovering causal relationships from observational data is a crucial problem and it has applications in many research areas. The PC algorithm is the state-of-the-art constraint based method for causal discovery. However, runtime of the PC algorithm, in the worst-case, is exponential to the number of nodes (variables), and thus it is inefficient when being applied to high dimensional data, e.g. gene expression datasets. On another note, the advancement of computer hardware in the last decade has resulted in the widespread availability of multi-core personal computers. There is a significant motivation for designing a parallelised PC algorithm that is suitable for personal computers and does not require end users' parallel computing knowledge beyond their competency in using the PC algorithm. In this paper, we develop parallel-PC, a fast and memory efficient PC algorithm using the parallel computing technique. We apply our method to a range of synthetic and real-world high dimensional datasets. Experimental results on a dataset from the DREAM 5 challenge show that the original PC algorithm could not produce any results after running more than 24 hours; meanwhile, our parallel-PC algorithm managed to finish within around 12 hours with a 4-core CPU computer, and less than 6 hours with a 8-core CPU computer. Furthermore, we integrate parallel-PC into a causal inference method for inferring miRNA-mRNA regulatory relationships. The experimental results show that parallel-PC helps improve both the efficiency and accuracy of the causal inference algorithm.
no_new_dataset
0.944434
1508.07372
Vijay Gadepally
Vijay Gadepally, Jake Bolewski, Dan Hook, Dylan Hutchison, Ben Miller, Jeremy Kepner
Graphulo: Linear Algebra Graph Kernels for NoSQL Databases
10 pages
null
10.1109/IPDPSW.2015.19
null
cs.DS cs.DB
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Big data and the Internet of Things era continue to challenge computational systems. Several technology solutions such as NoSQL databases have been developed to deal with this challenge. In order to generate meaningful results from large datasets, analysts often use a graph representation which provides an intuitive way to work with the data. Graph vertices can represent users and events, and edges can represent the relationship between vertices. Graph algorithms are used to extract meaningful information from these very large graphs. At MIT, the Graphulo initiative is an effort to perform graph algorithms directly in NoSQL databases such as Apache Accumulo or SciDB, which have an inherently sparse data storage scheme. Sparse matrix operations have a history of efficient implementations and the Graph Basic Linear Algebra Subprogram (GraphBLAS) community has developed a set of key kernels that can be used to develop efficient linear algebra operations. However, in order to use the GraphBLAS kernels, it is important that common graph algorithms be recast using the linear algebra building blocks. In this article, we look at common classes of graph algorithms and recast them into linear algebra operations using the GraphBLAS building blocks.
[ { "version": "v1", "created": "Fri, 28 Aug 2015 23:03:10 GMT" }, { "version": "v2", "created": "Tue, 6 Oct 2015 03:23:10 GMT" } ]
2016-11-11T00:00:00
[ [ "Gadepally", "Vijay", "" ], [ "Bolewski", "Jake", "" ], [ "Hook", "Dan", "" ], [ "Hutchison", "Dylan", "" ], [ "Miller", "Ben", "" ], [ "Kepner", "Jeremy", "" ] ]
TITLE: Graphulo: Linear Algebra Graph Kernels for NoSQL Databases ABSTRACT: Big data and the Internet of Things era continue to challenge computational systems. Several technology solutions such as NoSQL databases have been developed to deal with this challenge. In order to generate meaningful results from large datasets, analysts often use a graph representation which provides an intuitive way to work with the data. Graph vertices can represent users and events, and edges can represent the relationship between vertices. Graph algorithms are used to extract meaningful information from these very large graphs. At MIT, the Graphulo initiative is an effort to perform graph algorithms directly in NoSQL databases such as Apache Accumulo or SciDB, which have an inherently sparse data storage scheme. Sparse matrix operations have a history of efficient implementations and the Graph Basic Linear Algebra Subprogram (GraphBLAS) community has developed a set of key kernels that can be used to develop efficient linear algebra operations. However, in order to use the GraphBLAS kernels, it is important that common graph algorithms be recast using the linear algebra building blocks. In this article, we look at common classes of graph algorithms and recast them into linear algebra operations using the GraphBLAS building blocks.
no_new_dataset
0.940298
1611.01584
Brandon Smith
Brandon M. Smith and Charles R. Dyer
Efficient Branching Cascaded Regression for Face Alignment under Significant Head Rotation
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Despite much interest in face alignment in recent years, the large majority of work has focused on near-frontal faces. Algorithms typically break down on profile faces, or are too slow for real-time applications. In this work we propose an efficient approach to face alignment that can handle 180 degrees of head rotation in a unified way (e.g., without resorting to view-based models) using 2D training data. The foundation of our approach is cascaded shape regression (CSR), which has emerged recently as the leading strategy. We propose a generalization of conventional CSRs that we call branching cascaded regression (BCR). Conventional CSRs are single-track; that is, they progress from one cascade level to the next in a straight line, with each regressor attempting to fit the entire dataset. We instead split the regression problem into two or more simpler ones after each cascade level. Intuitively, each regressor can then operate on a simpler objective function (i.e., with fewer conflicting gradient directions). Within the BCR framework, we model and infer pose-related landmark visibility and face shape simultaneously using Structured Point Distribution Models (SPDMs). We propose to learn task-specific feature mapping functions that are adaptive to landmark visibility, and that use SPDM parameters as regression targets instead of 2D landmark coordinates. Additionally, we introduce a new in-the-wild dataset of profile faces to validate our approach.
[ { "version": "v1", "created": "Sat, 5 Nov 2016 01:42:39 GMT" }, { "version": "v2", "created": "Thu, 10 Nov 2016 04:53:39 GMT" } ]
2016-11-11T00:00:00
[ [ "Smith", "Brandon M.", "" ], [ "Dyer", "Charles R.", "" ] ]
TITLE: Efficient Branching Cascaded Regression for Face Alignment under Significant Head Rotation ABSTRACT: Despite much interest in face alignment in recent years, the large majority of work has focused on near-frontal faces. Algorithms typically break down on profile faces, or are too slow for real-time applications. In this work we propose an efficient approach to face alignment that can handle 180 degrees of head rotation in a unified way (e.g., without resorting to view-based models) using 2D training data. The foundation of our approach is cascaded shape regression (CSR), which has emerged recently as the leading strategy. We propose a generalization of conventional CSRs that we call branching cascaded regression (BCR). Conventional CSRs are single-track; that is, they progress from one cascade level to the next in a straight line, with each regressor attempting to fit the entire dataset. We instead split the regression problem into two or more simpler ones after each cascade level. Intuitively, each regressor can then operate on a simpler objective function (i.e., with fewer conflicting gradient directions). Within the BCR framework, we model and infer pose-related landmark visibility and face shape simultaneously using Structured Point Distribution Models (SPDMs). We propose to learn task-specific feature mapping functions that are adaptive to landmark visibility, and that use SPDM parameters as regression targets instead of 2D landmark coordinates. Additionally, we introduce a new in-the-wild dataset of profile faces to validate our approach.
no_new_dataset
0.949902
1611.01880
Nikita Jain
Nkita Jain and Rachita Gupta
Inductive decision based Real Time Occupancy detector in University Buildings
7 Pages 9 Figures, International Journal of Computer Science and Information Security Vol 14 No 10 2016
International Journal of Computer Science and Information Security 14 (10) 2016
null
null
cs.CY
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The ability to estimate College Campus Occupancy for Classrooms and Labs in real time has become one of the major concerns for various Academicians, authorities and administrators,where still a manual attendance marking system is being followed. Using a low budget multiple sensor setup installed in a college auditorium, the goal is to build a real-time occupancy detector. This paper presents an Inductive real time Decision tree based classifier using multiple sensor dataset to detect occupancy. Using simple feature based thresholds, Reverberation time which comes out to be a novel as well as most distinguishing feature sampled at various frequencies over a given time interval was used to detect the occupancy with an accuracy of %.Addition of various other sensor data, decreased the accuracy of classification results. The detector setup can be used in various college buildings to provide real time centralised occupancy status thus automating the manual attendance system being used.
[ { "version": "v1", "created": "Mon, 7 Nov 2016 03:02:01 GMT" } ]
2016-11-11T00:00:00
[ [ "Jain", "Nkita", "" ], [ "Gupta", "Rachita", "" ] ]
TITLE: Inductive decision based Real Time Occupancy detector in University Buildings ABSTRACT: The ability to estimate College Campus Occupancy for Classrooms and Labs in real time has become one of the major concerns for various Academicians, authorities and administrators,where still a manual attendance marking system is being followed. Using a low budget multiple sensor setup installed in a college auditorium, the goal is to build a real-time occupancy detector. This paper presents an Inductive real time Decision tree based classifier using multiple sensor dataset to detect occupancy. Using simple feature based thresholds, Reverberation time which comes out to be a novel as well as most distinguishing feature sampled at various frequencies over a given time interval was used to detect the occupancy with an accuracy of %.Addition of various other sensor data, decreased the accuracy of classification results. The detector setup can be used in various college buildings to provide real time centralised occupancy status thus automating the manual attendance system being used.
no_new_dataset
0.934873
1611.03159
Kifayat Khan
Kifayat Ullah Khan, Waqas Nawaz, Young-Koo Lee
Scalable Compression of a Weighted Graph
null
null
null
null
cs.DS
http://creativecommons.org/licenses/by-nc-sa/4.0/
Graph is a useful data structure to model various real life aspects like email communications, co-authorship among researchers, interactions among chemical compounds, and so on. Supporting such real life interactions produce a knowledge rich massive repository of data. However, efficiently understanding underlying trends and patterns is hard due to large size of the graph. Therefore, this paper presents a scalable compression solution to compute summary of a weighted graph. All the aforementioned interactions from various domains are represented as edge weights in a graph. Therefore, creating a summary graph while considering this vital aspect is necessary to learn insights of different communication patterns. By experimenting the proposed method on two real world and publically available datasets against a state of the art technique, we obtain order of magnitude performance gain and better summarization accuracy.
[ { "version": "v1", "created": "Thu, 10 Nov 2016 01:52:49 GMT" } ]
2016-11-11T00:00:00
[ [ "Khan", "Kifayat Ullah", "" ], [ "Nawaz", "Waqas", "" ], [ "Lee", "Young-Koo", "" ] ]
TITLE: Scalable Compression of a Weighted Graph ABSTRACT: Graph is a useful data structure to model various real life aspects like email communications, co-authorship among researchers, interactions among chemical compounds, and so on. Supporting such real life interactions produce a knowledge rich massive repository of data. However, efficiently understanding underlying trends and patterns is hard due to large size of the graph. Therefore, this paper presents a scalable compression solution to compute summary of a weighted graph. All the aforementioned interactions from various domains are represented as edge weights in a graph. Therefore, creating a summary graph while considering this vital aspect is necessary to learn insights of different communication patterns. By experimenting the proposed method on two real world and publically available datasets against a state of the art technique, we obtain order of magnitude performance gain and better summarization accuracy.
no_new_dataset
0.946892
1611.03214
Alexander Novikov
Timur Garipov, Dmitry Podoprikhin, Alexander Novikov, Dmitry Vetrov
Ultimate tensorization: compressing convolutional and FC layers alike
NIPS 2016 workshop: Learning with Tensors: Why Now and How?
null
null
null
cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Convolutional neural networks excel in image recognition tasks, but this comes at the cost of high computational and memory complexity. To tackle this problem, [1] developed a tensor factorization framework to compress fully-connected layers. In this paper, we focus on compressing convolutional layers. We show that while the direct application of the tensor framework [1] to the 4-dimensional kernel of convolution does compress the layer, we can do better. We reshape the convolutional kernel into a tensor of higher order and factorize it. We combine the proposed approach with the previous work to compress both convolutional and fully-connected layers of a network and achieve 80x network compression rate with 1.1% accuracy drop on the CIFAR-10 dataset.
[ { "version": "v1", "created": "Thu, 10 Nov 2016 08:07:46 GMT" } ]
2016-11-11T00:00:00
[ [ "Garipov", "Timur", "" ], [ "Podoprikhin", "Dmitry", "" ], [ "Novikov", "Alexander", "" ], [ "Vetrov", "Dmitry", "" ] ]
TITLE: Ultimate tensorization: compressing convolutional and FC layers alike ABSTRACT: Convolutional neural networks excel in image recognition tasks, but this comes at the cost of high computational and memory complexity. To tackle this problem, [1] developed a tensor factorization framework to compress fully-connected layers. In this paper, we focus on compressing convolutional layers. We show that while the direct application of the tensor framework [1] to the 4-dimensional kernel of convolution does compress the layer, we can do better. We reshape the convolutional kernel into a tensor of higher order and factorize it. We combine the proposed approach with the previous work to compress both convolutional and fully-connected layers of a network and achieve 80x network compression rate with 1.1% accuracy drop on the CIFAR-10 dataset.
no_new_dataset
0.949106
1611.03270
Adi Dafni
Adi Dafni, Yael Moses and Shai Avidan
Detecting Moving Regions in CrowdCam Images
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We address the novel problem of detecting dynamic regions in CrowdCam images, a set of still images captured by a group of people. These regions capture the most interesting parts of the scene, and detecting them plays an important role in the analysis of visual data. Our method is based on the observation that matching static points must satisfy the epipolar geometry constraints, but computing exact matches is challenging. Instead, we compute the probability that a pixel has a match, not necessarily the correct one, along the corresponding epipolar line. The complement of this probability is not necessarily the probability of a dynamic point because of occlusions, noise, and matching errors. Therefore, information from all pairs of images is aggregated to obtain a high quality dynamic probability map, per image. Experiments on challenging datasets demonstrate the effectiveness of the algorithm on a broad range of settings; no prior knowledge about the scene, the camera characteristics or the camera locations is required.
[ { "version": "v1", "created": "Thu, 10 Nov 2016 11:58:52 GMT" } ]
2016-11-11T00:00:00
[ [ "Dafni", "Adi", "" ], [ "Moses", "Yael", "" ], [ "Avidan", "Shai", "" ] ]
TITLE: Detecting Moving Regions in CrowdCam Images ABSTRACT: We address the novel problem of detecting dynamic regions in CrowdCam images, a set of still images captured by a group of people. These regions capture the most interesting parts of the scene, and detecting them plays an important role in the analysis of visual data. Our method is based on the observation that matching static points must satisfy the epipolar geometry constraints, but computing exact matches is challenging. Instead, we compute the probability that a pixel has a match, not necessarily the correct one, along the corresponding epipolar line. The complement of this probability is not necessarily the probability of a dynamic point because of occlusions, noise, and matching errors. Therefore, information from all pairs of images is aggregated to obtain a high quality dynamic probability map, per image. Experiments on challenging datasets demonstrate the effectiveness of the algorithm on a broad range of settings; no prior knowledge about the scene, the camera characteristics or the camera locations is required.
no_new_dataset
0.945801
1611.03298
Harsh Nisar
Deshana Desai, Harsh Nisar, Rishab Bhardawaj
Role of Temporal Diversity in Inferring Social Ties Based on Spatio-Temporal Data
7 pages, 3 figures
null
null
null
cs.SI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The last two decades have seen a tremendous surge in research on social networks and their implications. The studies includes inferring social relationships, which in turn have been used for target advertising, recommendations, search customization etc. However, the offline experiences of human, the conversations with people and face-to-face interactions that govern our lives interactions have received lesser attention. We introduce DAIICT Spatio-Temporal Network (DSSN), a spatiotemporal dataset of 0.7 million data points of continuous location data logged at an interval of every 2 minutes by mobile phones of 46 subjects. Our research is focused at inferring relationship strength between students based on the spatiotemporal data and comparing the results with the self-reported data. In that pursuit we introduce Temporal Diversity, which we show to be superior in its contribution to predicting relationship strength than its counterparts. We also explore the evolving nature of Temporal Diversity with time. Our rich dataset opens various other avenues of research that require fine-grained location data with bounded movement of participants within a limited geographical area. The advantage of having a bounded geographical area such as a university campus is that it provides us with a microcosm of the real world, where each such geographic zone has an internal context and function and a high percentage of mobility is governed by schedules and time-tables. The bounded geographical region in addition to the age homogeneous population gives us a minute look into the active internal socialization of students in a university.
[ { "version": "v1", "created": "Thu, 10 Nov 2016 13:42:05 GMT" } ]
2016-11-11T00:00:00
[ [ "Desai", "Deshana", "" ], [ "Nisar", "Harsh", "" ], [ "Bhardawaj", "Rishab", "" ] ]
TITLE: Role of Temporal Diversity in Inferring Social Ties Based on Spatio-Temporal Data ABSTRACT: The last two decades have seen a tremendous surge in research on social networks and their implications. The studies includes inferring social relationships, which in turn have been used for target advertising, recommendations, search customization etc. However, the offline experiences of human, the conversations with people and face-to-face interactions that govern our lives interactions have received lesser attention. We introduce DAIICT Spatio-Temporal Network (DSSN), a spatiotemporal dataset of 0.7 million data points of continuous location data logged at an interval of every 2 minutes by mobile phones of 46 subjects. Our research is focused at inferring relationship strength between students based on the spatiotemporal data and comparing the results with the self-reported data. In that pursuit we introduce Temporal Diversity, which we show to be superior in its contribution to predicting relationship strength than its counterparts. We also explore the evolving nature of Temporal Diversity with time. Our rich dataset opens various other avenues of research that require fine-grained location data with bounded movement of participants within a limited geographical area. The advantage of having a bounded geographical area such as a university campus is that it provides us with a microcosm of the real world, where each such geographic zone has an internal context and function and a high percentage of mobility is governed by schedules and time-tables. The bounded geographical region in addition to the age homogeneous population gives us a minute look into the active internal socialization of students in a university.
new_dataset
0.967625
1611.03313
Boyu Wang
Boyu Wang, Kevin Yager, Dantong Yu, Minh Hoai
X-ray Scattering Image Classification Using Deep Learning
null
null
null
null
cs.CV
http://creativecommons.org/licenses/by/4.0/
Visual inspection of x-ray scattering images is a powerful technique for probing the physical structure of materials at the molecular scale. In this paper, we explore the use of deep learning to develop methods for automatically analyzing x-ray scattering images. In particular, we apply Convolutional Neural Networks and Convolutional Autoencoders for x-ray scattering image classification. To acquire enough training data for deep learning, we use simulation software to generate synthetic x-ray scattering images. Experiments show that deep learning methods outperform previously published methods by 10\% on synthetic and real datasets.
[ { "version": "v1", "created": "Thu, 10 Nov 2016 14:32:24 GMT" } ]
2016-11-11T00:00:00
[ [ "Wang", "Boyu", "" ], [ "Yager", "Kevin", "" ], [ "Yu", "Dantong", "" ], [ "Hoai", "Minh", "" ] ]
TITLE: X-ray Scattering Image Classification Using Deep Learning ABSTRACT: Visual inspection of x-ray scattering images is a powerful technique for probing the physical structure of materials at the molecular scale. In this paper, we explore the use of deep learning to develop methods for automatically analyzing x-ray scattering images. In particular, we apply Convolutional Neural Networks and Convolutional Autoencoders for x-ray scattering image classification. To acquire enough training data for deep learning, we use simulation software to generate synthetic x-ray scattering images. Experiments show that deep learning methods outperform previously published methods by 10\% on synthetic and real datasets.
no_new_dataset
0.954563
1611.03382
Wenyuan Zeng
Wenyuan Zeng, Wenjie Luo, Sanja Fidler, Raquel Urtasun
Efficient Summarization with Read-Again and Copy Mechanism
11 pages, 4 figures, 5 tables
null
null
null
cs.CL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Encoder-decoder models have been widely used to solve sequence to sequence prediction tasks. However current approaches suffer from two shortcomings. First, the encoders compute a representation of each word taking into account only the history of the words it has read so far, yielding suboptimal representations. Second, current decoders utilize large vocabularies in order to minimize the problem of unknown words, resulting in slow decoding times. In this paper we address both shortcomings. Towards this goal, we first introduce a simple mechanism that first reads the input sequence before committing to a representation of each word. Furthermore, we propose a simple copy mechanism that is able to exploit very small vocabularies and handle out-of-vocabulary words. We demonstrate the effectiveness of our approach on the Gigaword dataset and DUC competition outperforming the state-of-the-art.
[ { "version": "v1", "created": "Thu, 10 Nov 2016 16:23:04 GMT" } ]
2016-11-11T00:00:00
[ [ "Zeng", "Wenyuan", "" ], [ "Luo", "Wenjie", "" ], [ "Fidler", "Sanja", "" ], [ "Urtasun", "Raquel", "" ] ]
TITLE: Efficient Summarization with Read-Again and Copy Mechanism ABSTRACT: Encoder-decoder models have been widely used to solve sequence to sequence prediction tasks. However current approaches suffer from two shortcomings. First, the encoders compute a representation of each word taking into account only the history of the words it has read so far, yielding suboptimal representations. Second, current decoders utilize large vocabularies in order to minimize the problem of unknown words, resulting in slow decoding times. In this paper we address both shortcomings. Towards this goal, we first introduce a simple mechanism that first reads the input sequence before committing to a representation of each word. Furthermore, we propose a simple copy mechanism that is able to exploit very small vocabularies and handle out-of-vocabulary words. We demonstrate the effectiveness of our approach on the Gigaword dataset and DUC competition outperforming the state-of-the-art.
no_new_dataset
0.947039
1611.03383
Junbo Zhao
Michael Mathieu, Junbo Zhao, Pablo Sprechmann, Aditya Ramesh, Yann LeCun
Disentangling factors of variation in deep representations using adversarial training
Conference paper in NIPS 2016
null
null
null
cs.LG stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We introduce a conditional generative model for learning to disentangle the hidden factors of variation within a set of labeled observations, and separate them into complementary codes. One code summarizes the specified factors of variation associated with the labels. The other summarizes the remaining unspecified variability. During training, the only available source of supervision comes from our ability to distinguish among different observations belonging to the same class. Examples of such observations include images of a set of labeled objects captured at different viewpoints, or recordings of set of speakers dictating multiple phrases. In both instances, the intra-class diversity is the source of the unspecified factors of variation: each object is observed at multiple viewpoints, and each speaker dictates multiple phrases. Learning to disentangle the specified factors from the unspecified ones becomes easier when strong supervision is possible. Suppose that during training, we have access to pairs of images, where each pair shows two different objects captured from the same viewpoint. This source of alignment allows us to solve our task using existing methods. However, labels for the unspecified factors are usually unavailable in realistic scenarios where data acquisition is not strictly controlled. We address the problem of disentanglement in this more general setting by combining deep convolutional autoencoders with a form of adversarial training. Both factors of variation are implicitly captured in the organization of the learned embedding space, and can be used for solving single-image analogies. Experimental results on synthetic and real datasets show that the proposed method is capable of generalizing to unseen classes and intra-class variabilities.
[ { "version": "v1", "created": "Thu, 10 Nov 2016 16:24:16 GMT" } ]
2016-11-11T00:00:00
[ [ "Mathieu", "Michael", "" ], [ "Zhao", "Junbo", "" ], [ "Sprechmann", "Pablo", "" ], [ "Ramesh", "Aditya", "" ], [ "LeCun", "Yann", "" ] ]
TITLE: Disentangling factors of variation in deep representations using adversarial training ABSTRACT: We introduce a conditional generative model for learning to disentangle the hidden factors of variation within a set of labeled observations, and separate them into complementary codes. One code summarizes the specified factors of variation associated with the labels. The other summarizes the remaining unspecified variability. During training, the only available source of supervision comes from our ability to distinguish among different observations belonging to the same class. Examples of such observations include images of a set of labeled objects captured at different viewpoints, or recordings of set of speakers dictating multiple phrases. In both instances, the intra-class diversity is the source of the unspecified factors of variation: each object is observed at multiple viewpoints, and each speaker dictates multiple phrases. Learning to disentangle the specified factors from the unspecified ones becomes easier when strong supervision is possible. Suppose that during training, we have access to pairs of images, where each pair shows two different objects captured from the same viewpoint. This source of alignment allows us to solve our task using existing methods. However, labels for the unspecified factors are usually unavailable in realistic scenarios where data acquisition is not strictly controlled. We address the problem of disentanglement in this more general setting by combining deep convolutional autoencoders with a form of adversarial training. Both factors of variation are implicitly captured in the organization of the learned embedding space, and can be used for solving single-image analogies. Experimental results on synthetic and real datasets show that the proposed method is capable of generalizing to unseen classes and intra-class variabilities.
no_new_dataset
0.9463
1611.03403
Rui A. P. Perdig\~ao
Rui A. P. Perdig\~ao, Carlos A. L. Pires, Julia Hall
Synergistic Dynamic Theory of Complex Coevolutionary Systems: Disentangling Nonlinear Spatiotemporal Controls on Precipitation
40 pages, 10 figures
null
null
null
math.DS physics.ao-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We formulate a nonlinear synergistic theory of coevolutionary systems, disentangling and explaining dynamic complexity in terms of fundamental processes for optimised data analysis and dynamic model design: Dynamic Source Analysis (DSA). DSA provides a nonlinear dynamical basis for spatiotemporal datasets or dynamical models, eliminating redundancies and expressing the system in terms of the smallest number of fundamental processes and interactions without loss of information. This optimises model design in dynamical systems, expressing complex coevolution in simple synergistic terms, yielding physically meaningful spatial and temporal structures. These are extracted by spatiotemporal decomposition of nonlinearly interacting subspaces via the novel concept of a Spatiotemporal Coevolution Manifold. Physical consistency is ensured and mathematical ambiguities are avoided with fundamental principles on energy minimisation and entropy production. The relevance of DSA is illustrated by retrieving a non-redundant, synergistic set of nonlinear geophysical processes exerting control over precipitation in space and time over the Euro-Atlantic region. For that purpose, a nonlinear spatiotemporal basis is extracted from geopotential data fields, yielding two independent dynamic sources dominated respectively by meridional and zonal circulation gradients. These sources are decomposed into spatial and temporal structures corresponding to multiscale climate dynamics. The added value of nonlinear predictability is brought out in the geospatial evaluation and dynamic simulation of evolving precipitation distributions from the geophysical controls, using DSA-driven model building and implementation. The simulated precipitation is found to be in agreement with observational data, which they not only describe but also dynamically link and attribute in synergistic terms of the retrieved dynamic sources.
[ { "version": "v1", "created": "Thu, 10 Nov 2016 17:13:57 GMT" } ]
2016-11-11T00:00:00
[ [ "Perdigão", "Rui A. P.", "" ], [ "Pires", "Carlos A. L.", "" ], [ "Hall", "Julia", "" ] ]
TITLE: Synergistic Dynamic Theory of Complex Coevolutionary Systems: Disentangling Nonlinear Spatiotemporal Controls on Precipitation ABSTRACT: We formulate a nonlinear synergistic theory of coevolutionary systems, disentangling and explaining dynamic complexity in terms of fundamental processes for optimised data analysis and dynamic model design: Dynamic Source Analysis (DSA). DSA provides a nonlinear dynamical basis for spatiotemporal datasets or dynamical models, eliminating redundancies and expressing the system in terms of the smallest number of fundamental processes and interactions without loss of information. This optimises model design in dynamical systems, expressing complex coevolution in simple synergistic terms, yielding physically meaningful spatial and temporal structures. These are extracted by spatiotemporal decomposition of nonlinearly interacting subspaces via the novel concept of a Spatiotemporal Coevolution Manifold. Physical consistency is ensured and mathematical ambiguities are avoided with fundamental principles on energy minimisation and entropy production. The relevance of DSA is illustrated by retrieving a non-redundant, synergistic set of nonlinear geophysical processes exerting control over precipitation in space and time over the Euro-Atlantic region. For that purpose, a nonlinear spatiotemporal basis is extracted from geopotential data fields, yielding two independent dynamic sources dominated respectively by meridional and zonal circulation gradients. These sources are decomposed into spatial and temporal structures corresponding to multiscale climate dynamics. The added value of nonlinear predictability is brought out in the geospatial evaluation and dynamic simulation of evolving precipitation distributions from the geophysical controls, using DSA-driven model building and implementation. The simulated precipitation is found to be in agreement with observational data, which they not only describe but also dynamically link and attribute in synergistic terms of the retrieved dynamic sources.
no_new_dataset
0.948155
1611.03404
Jeffrey Regier
Jeffrey Regier, Kiran Pamnany, Ryan Giordano, Rollin Thomas, David Schlegel, Jon McAuliffe and Prabhat
Learning an Astronomical Catalog of the Visible Universe through Scalable Bayesian Inference
submitting to IPDPS'17
null
null
null
cs.DC astro-ph.IM cs.LG stat.AP stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Celeste is a procedure for inferring astronomical catalogs that attains state-of-the-art scientific results. To date, Celeste has been scaled to at most hundreds of megabytes of astronomical images: Bayesian posterior inference is notoriously demanding computationally. In this paper, we report on a scalable, parallel version of Celeste, suitable for learning catalogs from modern large-scale astronomical datasets. Our algorithmic innovations include a fast numerical optimization routine for Bayesian posterior inference and a statistically efficient scheme for decomposing astronomical optimization problems into subproblems. Our scalable implementation is written entirely in Julia, a new high-level dynamic programming language designed for scientific and numerical computing. We use Julia's high-level constructs for shared and distributed memory parallelism, and demonstrate effective load balancing and efficient scaling on up to 8192 Xeon cores on the NERSC Cori supercomputer.
[ { "version": "v1", "created": "Thu, 10 Nov 2016 17:16:04 GMT" } ]
2016-11-11T00:00:00
[ [ "Regier", "Jeffrey", "" ], [ "Pamnany", "Kiran", "" ], [ "Giordano", "Ryan", "" ], [ "Thomas", "Rollin", "" ], [ "Schlegel", "David", "" ], [ "McAuliffe", "Jon", "" ], [ "Prabhat", "", "" ] ]
TITLE: Learning an Astronomical Catalog of the Visible Universe through Scalable Bayesian Inference ABSTRACT: Celeste is a procedure for inferring astronomical catalogs that attains state-of-the-art scientific results. To date, Celeste has been scaled to at most hundreds of megabytes of astronomical images: Bayesian posterior inference is notoriously demanding computationally. In this paper, we report on a scalable, parallel version of Celeste, suitable for learning catalogs from modern large-scale astronomical datasets. Our algorithmic innovations include a fast numerical optimization routine for Bayesian posterior inference and a statistically efficient scheme for decomposing astronomical optimization problems into subproblems. Our scalable implementation is written entirely in Julia, a new high-level dynamic programming language designed for scientific and numerical computing. We use Julia's high-level constructs for shared and distributed memory parallelism, and demonstrate effective load balancing and efficient scaling on up to 8192 Xeon cores on the NERSC Cori supercomputer.
no_new_dataset
0.941815
1611.03426
Ernesto Diaz-Aviles
Avar\'e Stewart, Sara Romano, Nattiya Kanhabua, Sergio Di Martino, Wolf Siberski, Antonino Mazzeo, Wolfgang Nejdl, and Ernesto Diaz-Aviles
Why is it Difficult to Detect Sudden and Unexpected Epidemic Outbreaks in Twitter?
ACM CCS Concepts: Applied computing - Health informatics; Information systems - Web mining; Document filtering; Novelty in information retrieval; Recommender systems; Human-centered computing - Social media
null
null
null
cs.CY cs.IR cs.SI stat.ML
http://creativecommons.org/licenses/by-sa/4.0/
Social media services such as Twitter are a valuable source of information for decision support systems. Many studies have shown that this also holds for the medical domain, where Twitter is considered a viable tool for public health officials to sift through relevant information for the early detection, management, and control of epidemic outbreaks. This is possible due to the inherent capability of social media services to transmit information faster than traditional channels. However, the majority of current studies have limited their scope to the detection of common and seasonal health recurring events (e.g., Influenza-like Illness), partially due to the noisy nature of Twitter data, which makes outbreak detection and management very challenging. Within the European project M-Eco, we developed a Twitter-based Epidemic Intelligence (EI) system, which is designed to also handle a more general class of unexpected and aperiodic outbreaks. In particular, we faced three main research challenges in this endeavor: 1) dynamic classification to manage terminology evolution of Twitter messages, 2) alert generation to produce reliable outbreak alerts analyzing the (noisy) tweet time series, and 3) ranking and recommendation to support domain experts for better assessment of the generated alerts. In this paper, we empirically evaluate our proposed approach to these challenges using real-world outbreak datasets and a large collection of tweets. We validate our solution with domain experts, describe our experiences, and give a more realistic view on the benefits and issues of analyzing social media for public health.
[ { "version": "v1", "created": "Thu, 10 Nov 2016 17:53:33 GMT" } ]
2016-11-11T00:00:00
[ [ "Stewart", "Avaré", "" ], [ "Romano", "Sara", "" ], [ "Kanhabua", "Nattiya", "" ], [ "Di Martino", "Sergio", "" ], [ "Siberski", "Wolf", "" ], [ "Mazzeo", "Antonino", "" ], [ "Nejdl", "Wolfgang", "" ], [ "Diaz-Aviles", "Ernesto", "" ] ]
TITLE: Why is it Difficult to Detect Sudden and Unexpected Epidemic Outbreaks in Twitter? ABSTRACT: Social media services such as Twitter are a valuable source of information for decision support systems. Many studies have shown that this also holds for the medical domain, where Twitter is considered a viable tool for public health officials to sift through relevant information for the early detection, management, and control of epidemic outbreaks. This is possible due to the inherent capability of social media services to transmit information faster than traditional channels. However, the majority of current studies have limited their scope to the detection of common and seasonal health recurring events (e.g., Influenza-like Illness), partially due to the noisy nature of Twitter data, which makes outbreak detection and management very challenging. Within the European project M-Eco, we developed a Twitter-based Epidemic Intelligence (EI) system, which is designed to also handle a more general class of unexpected and aperiodic outbreaks. In particular, we faced three main research challenges in this endeavor: 1) dynamic classification to manage terminology evolution of Twitter messages, 2) alert generation to produce reliable outbreak alerts analyzing the (noisy) tweet time series, and 3) ranking and recommendation to support domain experts for better assessment of the generated alerts. In this paper, we empirically evaluate our proposed approach to these challenges using real-world outbreak datasets and a large collection of tweets. We validate our solution with domain experts, describe our experiences, and give a more realistic view on the benefits and issues of analyzing social media for public health.
no_new_dataset
0.944638
1604.07287
Uran Ferizi
Uran Ferizi, Benoit Scherrer, Torben Schneider, Mohammad Alipoor, Odin Eufracio, Rutger H.J. Fick, Rachid Deriche, Markus Nilsson, Ana K. Loya-Olivas, Mariano Rivera, Dirk H.J. Poot, Alonso Ramirez-Manzanares, Jose L. Marroquin, Ariel Rokem, Christian P\"otter, Robert F. Dougherty, Ken Sakaie, Claudia Wheeler-Kingshott, Simon K. Warfield, Thomas Witzel, Lawrence L. Wald, Jos\'e G. Raya, Daniel C. Alexander
Diffusion MRI microstructure models with in vivo human brain Connectom data: results from a multi-group comparison
null
null
null
null
physics.med-ph q-bio.NC
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A large number of mathematical models have been proposed to describe the measured signal in diffusion-weighted (DW) magnetic resonance imaging (MRI) and infer properties about the white matter microstructure. However, a head-to-head comparison of DW-MRI models is critically missing in the field. To address this deficiency, we organized the "White Matter Modeling Challenge" during the International Symposium on Biomedical Imaging (ISBI) 2015 conference. This competition aimed at identifying the DW-MRI models that best predict unseen DW data. in vivo DW-MRI data was acquired on the Connectom scanner at the A.A.Martinos Center (Massachusetts General Hospital) using gradients strength of up to 300 mT/m and a broad set of diffusion times. We focused on assessing the DW signal prediction in two regions: the genu in the corpus callosum, where the fibres are relatively straight and parallel, and the fornix, where the configuration of fibres is more complex. The challenge participants had access to three-quarters of the whole dataset, and their models were ranked on their ability to predict the remaining unseen quarter of data. In this paper we provide both an overview and a more in-depth description of each evaluated model, report the challenge results, and infer trends about the model characteristics that were associated with high model ranking. This work provides a much needed benchmark for DW-MRI models. The acquired data and model details for signal prediction evaluation are provided online to encourage a larger scale assessment of diffusion models in the future.
[ { "version": "v1", "created": "Mon, 25 Apr 2016 14:44:28 GMT" }, { "version": "v2", "created": "Wed, 9 Nov 2016 14:48:25 GMT" } ]
2016-11-10T00:00:00
[ [ "Ferizi", "Uran", "" ], [ "Scherrer", "Benoit", "" ], [ "Schneider", "Torben", "" ], [ "Alipoor", "Mohammad", "" ], [ "Eufracio", "Odin", "" ], [ "Fick", "Rutger H. J.", "" ], [ "Deriche", "Rachid", "" ], [ "Nilsson", "Markus", "" ], [ "Loya-Olivas", "Ana K.", "" ], [ "Rivera", "Mariano", "" ], [ "Poot", "Dirk H. J.", "" ], [ "Ramirez-Manzanares", "Alonso", "" ], [ "Marroquin", "Jose L.", "" ], [ "Rokem", "Ariel", "" ], [ "Pötter", "Christian", "" ], [ "Dougherty", "Robert F.", "" ], [ "Sakaie", "Ken", "" ], [ "Wheeler-Kingshott", "Claudia", "" ], [ "Warfield", "Simon K.", "" ], [ "Witzel", "Thomas", "" ], [ "Wald", "Lawrence L.", "" ], [ "Raya", "José G.", "" ], [ "Alexander", "Daniel C.", "" ] ]
TITLE: Diffusion MRI microstructure models with in vivo human brain Connectom data: results from a multi-group comparison ABSTRACT: A large number of mathematical models have been proposed to describe the measured signal in diffusion-weighted (DW) magnetic resonance imaging (MRI) and infer properties about the white matter microstructure. However, a head-to-head comparison of DW-MRI models is critically missing in the field. To address this deficiency, we organized the "White Matter Modeling Challenge" during the International Symposium on Biomedical Imaging (ISBI) 2015 conference. This competition aimed at identifying the DW-MRI models that best predict unseen DW data. in vivo DW-MRI data was acquired on the Connectom scanner at the A.A.Martinos Center (Massachusetts General Hospital) using gradients strength of up to 300 mT/m and a broad set of diffusion times. We focused on assessing the DW signal prediction in two regions: the genu in the corpus callosum, where the fibres are relatively straight and parallel, and the fornix, where the configuration of fibres is more complex. The challenge participants had access to three-quarters of the whole dataset, and their models were ranked on their ability to predict the remaining unseen quarter of data. In this paper we provide both an overview and a more in-depth description of each evaluated model, report the challenge results, and infer trends about the model characteristics that were associated with high model ranking. This work provides a much needed benchmark for DW-MRI models. The acquired data and model details for signal prediction evaluation are provided online to encourage a larger scale assessment of diffusion models in the future.
no_new_dataset
0.948822
1606.02245
Alessandro Sordoni
Alessandro Sordoni and Philip Bachman and Adam Trischler and Yoshua Bengio
Iterative Alternating Neural Attention for Machine Reading
null
null
null
null
cs.CL cs.NE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a novel neural attention architecture to tackle machine comprehension tasks, such as answering Cloze-style queries with respect to a document. Unlike previous models, we do not collapse the query into a single vector, instead we deploy an iterative alternating attention mechanism that allows a fine-grained exploration of both the query and the document. Our model outperforms state-of-the-art baselines in standard machine comprehension benchmarks such as CNN news articles and the Children's Book Test (CBT) dataset.
[ { "version": "v1", "created": "Tue, 7 Jun 2016 18:25:48 GMT" }, { "version": "v2", "created": "Wed, 8 Jun 2016 18:17:03 GMT" }, { "version": "v3", "created": "Fri, 10 Jun 2016 21:16:56 GMT" }, { "version": "v4", "created": "Wed, 9 Nov 2016 18:11:09 GMT" } ]
2016-11-10T00:00:00
[ [ "Sordoni", "Alessandro", "" ], [ "Bachman", "Philip", "" ], [ "Trischler", "Adam", "" ], [ "Bengio", "Yoshua", "" ] ]
TITLE: Iterative Alternating Neural Attention for Machine Reading ABSTRACT: We propose a novel neural attention architecture to tackle machine comprehension tasks, such as answering Cloze-style queries with respect to a document. Unlike previous models, we do not collapse the query into a single vector, instead we deploy an iterative alternating attention mechanism that allows a fine-grained exploration of both the query and the document. Our model outperforms state-of-the-art baselines in standard machine comprehension benchmarks such as CNN news articles and the Children's Book Test (CBT) dataset.
no_new_dataset
0.940681
1611.00142
Binod Bhattarai
Binod Bhattarai, Gaurav Sharma, Frederic Jurie
Deep fusion of visual signatures for client-server facial analysis
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Facial analysis is a key technology for enabling human-machine interaction. In this context, we present a client-server framework, where a client transmits the signature of a face to be analyzed to the server, and, in return, the server sends back various information describing the face e.g. is the person male or female, is she/he bald, does he have a mustache, etc. We assume that a client can compute one (or a combination) of visual features; from very simple and efficient features, like Local Binary Patterns, to more complex and computationally heavy, like Fisher Vectors and CNN based, depending on the computing resources available. The challenge addressed in this paper is to design a common universal representation such that a single merged signature is transmitted to the server, whatever be the type and number of features computed by the client, ensuring nonetheless an optimal performance. Our solution is based on learning of a common optimal subspace for aligning the different face features and merging them into a universal signature. We have validated the proposed method on the challenging CelebA dataset, on which our method outperforms existing state-of-the-art methods when rich representation is available at test time, while giving competitive performance when only simple signatures (like LBP) are available at test time due to resource constraints on the client.
[ { "version": "v1", "created": "Tue, 1 Nov 2016 06:57:58 GMT" }, { "version": "v2", "created": "Wed, 9 Nov 2016 10:48:58 GMT" } ]
2016-11-10T00:00:00
[ [ "Bhattarai", "Binod", "" ], [ "Sharma", "Gaurav", "" ], [ "Jurie", "Frederic", "" ] ]
TITLE: Deep fusion of visual signatures for client-server facial analysis ABSTRACT: Facial analysis is a key technology for enabling human-machine interaction. In this context, we present a client-server framework, where a client transmits the signature of a face to be analyzed to the server, and, in return, the server sends back various information describing the face e.g. is the person male or female, is she/he bald, does he have a mustache, etc. We assume that a client can compute one (or a combination) of visual features; from very simple and efficient features, like Local Binary Patterns, to more complex and computationally heavy, like Fisher Vectors and CNN based, depending on the computing resources available. The challenge addressed in this paper is to design a common universal representation such that a single merged signature is transmitted to the server, whatever be the type and number of features computed by the client, ensuring nonetheless an optimal performance. Our solution is based on learning of a common optimal subspace for aligning the different face features and merging them into a universal signature. We have validated the proposed method on the challenging CelebA dataset, on which our method outperforms existing state-of-the-art methods when rich representation is available at test time, while giving competitive performance when only simple signatures (like LBP) are available at test time due to resource constraints on the client.
no_new_dataset
0.946349
1611.02776
Daoyuan Jia
Daoyuan Jia, Yongchi Su, Chunping Li
Deep Convolutional Neural Network for 6-DOF Image Localization
will update soon
null
null
null
cs.CV
http://creativecommons.org/licenses/by/4.0/
We present an accurate and robust method for six degree of freedom image localization. There are two key-points of our method, 1. automatic immense photo synthesis and labeling from point cloud model and, 2. pose estimation with deep convolutional neural networks regression. Our model can directly regresses 6-DOF camera poses from images, accurately describing where and how it was captured. We achieved an accuracy within 1 meters and 1 degree on our out-door dataset, which covers about 2 acres on our school campus.
[ { "version": "v1", "created": "Tue, 8 Nov 2016 23:59:16 GMT" } ]
2016-11-10T00:00:00
[ [ "Jia", "Daoyuan", "" ], [ "Su", "Yongchi", "" ], [ "Li", "Chunping", "" ] ]
TITLE: Deep Convolutional Neural Network for 6-DOF Image Localization ABSTRACT: We present an accurate and robust method for six degree of freedom image localization. There are two key-points of our method, 1. automatic immense photo synthesis and labeling from point cloud model and, 2. pose estimation with deep convolutional neural networks regression. Our model can directly regresses 6-DOF camera poses from images, accurately describing where and how it was captured. We achieved an accuracy within 1 meters and 1 degree on our out-door dataset, which covers about 2 acres on our school campus.
no_new_dataset
0.75005
1611.02792
Dhireesha Kudithipudi
Lennard Streat, Dhireesha Kudithipudi, Kevin Gomez
Non-volatile Hierarchical Temporal Memory: Hardware for Spatial Pooling
null
null
null
null
cs.AR
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Hierarchical Temporal Memory (HTM) is a biomimetic machine learning algorithm imbibing the structural and algorithmic properties of the neocortex. Two main functional components of HTM that enable spatio-temporal processing are the spatial pooler and temporal memory. In this research, we explore a scalable hardware realization of the spatial pooler closely coupled with the mathematical formulation of spatial pooler. This class of neuromorphic algorithms are advantageous in solving a subset of the future engineering problems by extracting nonintuitive patterns in complex data. The proposed architecture, Non-volatile HTM (NVHTM), leverages large-scale solid state flash memory to realize a optimal memory organization, area and power envelope. A behavioral model of NVHTM is evaluated against the MNIST dataset, yielding 91.98% classification accuracy. A full custom layout is developed to validate the design in a TSMC 180nm process. The area and power profile of the spatial pooler are 30.538mm2 and 64.394mW, respectively. This design is a proof-of-concept that storage processing is a viable platform for large scale HTM network models.
[ { "version": "v1", "created": "Wed, 9 Nov 2016 01:25:59 GMT" } ]
2016-11-10T00:00:00
[ [ "Streat", "Lennard", "" ], [ "Kudithipudi", "Dhireesha", "" ], [ "Gomez", "Kevin", "" ] ]
TITLE: Non-volatile Hierarchical Temporal Memory: Hardware for Spatial Pooling ABSTRACT: Hierarchical Temporal Memory (HTM) is a biomimetic machine learning algorithm imbibing the structural and algorithmic properties of the neocortex. Two main functional components of HTM that enable spatio-temporal processing are the spatial pooler and temporal memory. In this research, we explore a scalable hardware realization of the spatial pooler closely coupled with the mathematical formulation of spatial pooler. This class of neuromorphic algorithms are advantageous in solving a subset of the future engineering problems by extracting nonintuitive patterns in complex data. The proposed architecture, Non-volatile HTM (NVHTM), leverages large-scale solid state flash memory to realize a optimal memory organization, area and power envelope. A behavioral model of NVHTM is evaluated against the MNIST dataset, yielding 91.98% classification accuracy. A full custom layout is developed to validate the design in a TSMC 180nm process. The area and power profile of the spatial pooler are 30.538mm2 and 64.394mW, respectively. This design is a proof-of-concept that storage processing is a viable platform for large scale HTM network models.
no_new_dataset
0.946151
1510.04822
Massil Achab
Massil Achab (CMAP), Agathe Guilloux (LSTA), St\'ephane Ga\"iffas (CMAP) and Emmanuel Bacry (CMAP)
SGD with Variance Reduction beyond Empirical Risk Minimization
17 pages
null
null
null
stat.ML cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We introduce a doubly stochastic proximal gradient algorithm for optimizing a finite average of smooth convex functions, whose gradients depend on numerically expensive expectations. Our main motivation is the acceleration of the optimization of the regularized Cox partial-likelihood (the core model used in survival analysis), but our algorithm can be used in different settings as well. The proposed algorithm is doubly stochastic in the sense that gradient steps are done using stochastic gradient descent (SGD) with variance reduction, where the inner expectations are approximated by a Monte-Carlo Markov-Chain (MCMC) algorithm. We derive conditions on the MCMC number of iterations guaranteeing convergence, and obtain a linear rate of convergence under strong convexity and a sublinear rate without this assumption. We illustrate the fact that our algorithm improves the state-of-the-art solver for regularized Cox partial-likelihood on several datasets from survival analysis.
[ { "version": "v1", "created": "Fri, 16 Oct 2015 09:32:24 GMT" }, { "version": "v2", "created": "Mon, 19 Oct 2015 19:45:58 GMT" }, { "version": "v3", "created": "Tue, 8 Nov 2016 09:43:23 GMT" } ]
2016-11-09T00:00:00
[ [ "Achab", "Massil", "", "CMAP" ], [ "Guilloux", "Agathe", "", "LSTA" ], [ "Gaïffas", "Stéphane", "", "CMAP" ], [ "Bacry", "Emmanuel", "", "CMAP" ] ]
TITLE: SGD with Variance Reduction beyond Empirical Risk Minimization ABSTRACT: We introduce a doubly stochastic proximal gradient algorithm for optimizing a finite average of smooth convex functions, whose gradients depend on numerically expensive expectations. Our main motivation is the acceleration of the optimization of the regularized Cox partial-likelihood (the core model used in survival analysis), but our algorithm can be used in different settings as well. The proposed algorithm is doubly stochastic in the sense that gradient steps are done using stochastic gradient descent (SGD) with variance reduction, where the inner expectations are approximated by a Monte-Carlo Markov-Chain (MCMC) algorithm. We derive conditions on the MCMC number of iterations guaranteeing convergence, and obtain a linear rate of convergence under strong convexity and a sublinear rate without this assumption. We illustrate the fact that our algorithm improves the state-of-the-art solver for regularized Cox partial-likelihood on several datasets from survival analysis.
no_new_dataset
0.947088
1512.02109
Anmer Daskin
Anmer Daskin
Obtaining A Linear Combination of the Principal Components of a Matrix on Quantum Computers
The title of the paper is changed. A couple of sections are extended. 8 pages and 3 figures
Quantum Inf Process (2016) 15: 4013
10.1007/s11128-016-1388-7
null
quant-ph cs.LG math.ST stat.TH
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Principal component analysis is a multivariate statistical method frequently used in science and engineering to reduce the dimension of a problem or extract the most significant features from a dataset. In this paper, using a similar notion to the quantum counting, we show how to apply the amplitude amplification together with the phase estimation algorithm to an operator in order to procure the eigenvectors of the operator associated to the eigenvalues defined in the range $\left[a, b\right]$, where $a$ and $b$ are real and $0 \leq a \leq b \leq 1$. This makes possible to obtain a combination of the eigenvectors associated to the largest eigenvalues and so can be used to do principal component analysis on quantum computers.
[ { "version": "v1", "created": "Thu, 26 Nov 2015 14:31:12 GMT" }, { "version": "v2", "created": "Wed, 9 Dec 2015 13:37:00 GMT" }, { "version": "v3", "created": "Thu, 28 Jan 2016 09:53:59 GMT" } ]
2016-11-09T00:00:00
[ [ "Daskin", "Anmer", "" ] ]
TITLE: Obtaining A Linear Combination of the Principal Components of a Matrix on Quantum Computers ABSTRACT: Principal component analysis is a multivariate statistical method frequently used in science and engineering to reduce the dimension of a problem or extract the most significant features from a dataset. In this paper, using a similar notion to the quantum counting, we show how to apply the amplitude amplification together with the phase estimation algorithm to an operator in order to procure the eigenvectors of the operator associated to the eigenvalues defined in the range $\left[a, b\right]$, where $a$ and $b$ are real and $0 \leq a \leq b \leq 1$. This makes possible to obtain a combination of the eigenvectors associated to the largest eigenvalues and so can be used to do principal component analysis on quantum computers.
no_new_dataset
0.948058
1602.05100
Abolfazl Asudeh
Abolfazl Asudeh and Nan Zhang and Gautam Das
Query Reranking As A Service
Proceedings of the VLDB Endowment (PVLDB), Vol. 9, No. 11, 2016
Proceedings of the VLDB Endowment (PVLDB), Vol 9, No 11, 2016
10.14778/2983200.2983205
null
cs.DB
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The ranked retrieval model has rapidly become the de facto way for search query processing in client-server databases, especially those on the web. Despite of the extensive efforts in the database community on designing better ranking functions/mechanisms, many such databases in practice still fail to address the diverse and sometimes contradicting preferences of users on tuple ranking, perhaps (at least partially) due to the lack of expertise and/or motivation for the database owner to design truly effective ranking functions. This paper takes a different route on addressing the issue by defining a novel {\em query reranking problem}, i.e., we aim to design a third-party service that uses nothing but the public search interface of a client-server database to enable the on-the-fly processing of queries with any user-specified ranking functions (with or without selection conditions), no matter if the ranking function is supported by the database or not. We analyze the worst-case complexity of the problem and introduce a number of ideas, e.g., on-the-fly indexing, domination detection and virtual tuple pruning, to reduce the average-case cost of the query reranking algorithm. We also present extensive experimental results on real-world datasets, in both offline and live online systems, that demonstrate the effectiveness of our proposed techniques.
[ { "version": "v1", "created": "Sun, 7 Feb 2016 04:03:26 GMT" }, { "version": "v2", "created": "Sat, 16 Jul 2016 18:47:43 GMT" } ]
2016-11-09T00:00:00
[ [ "Asudeh", "Abolfazl", "" ], [ "Zhang", "Nan", "" ], [ "Das", "Gautam", "" ] ]
TITLE: Query Reranking As A Service ABSTRACT: The ranked retrieval model has rapidly become the de facto way for search query processing in client-server databases, especially those on the web. Despite of the extensive efforts in the database community on designing better ranking functions/mechanisms, many such databases in practice still fail to address the diverse and sometimes contradicting preferences of users on tuple ranking, perhaps (at least partially) due to the lack of expertise and/or motivation for the database owner to design truly effective ranking functions. This paper takes a different route on addressing the issue by defining a novel {\em query reranking problem}, i.e., we aim to design a third-party service that uses nothing but the public search interface of a client-server database to enable the on-the-fly processing of queries with any user-specified ranking functions (with or without selection conditions), no matter if the ranking function is supported by the database or not. We analyze the worst-case complexity of the problem and introduce a number of ideas, e.g., on-the-fly indexing, domination detection and virtual tuple pruning, to reduce the average-case cost of the query reranking algorithm. We also present extensive experimental results on real-world datasets, in both offline and live online systems, that demonstrate the effectiveness of our proposed techniques.
no_new_dataset
0.946597
1603.04779
Yanghao Li
Yanghao Li, Naiyan Wang, Jianping Shi, Jiaying Liu, Xiaodi Hou
Revisiting Batch Normalization For Practical Domain Adaptation
null
null
null
null
cs.CV cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Deep neural networks (DNN) have shown unprecedented success in various computer vision applications such as image classification and object detection. However, it is still a common annoyance during the training phase, that one has to prepare at least thousands of labeled images to fine-tune a network to a specific domain. Recent study (Tommasi et al. 2015) shows that a DNN has strong dependency towards the training dataset, and the learned features cannot be easily transferred to a different but relevant task without fine-tuning. In this paper, we propose a simple yet powerful remedy, called Adaptive Batch Normalization (AdaBN) to increase the generalization ability of a DNN. By modulating the statistics in all Batch Normalization layers across the network, our approach achieves deep adaptation effect for domain adaptation tasks. In contrary to other deep learning domain adaptation methods, our method does not require additional components, and is parameter-free. It archives state-of-the-art performance despite its surprising simplicity. Furthermore, we demonstrate that our method is complementary with other existing methods. Combining AdaBN with existing domain adaptation treatments may further improve model performance.
[ { "version": "v1", "created": "Tue, 15 Mar 2016 17:44:32 GMT" }, { "version": "v2", "created": "Wed, 16 Mar 2016 03:57:19 GMT" }, { "version": "v3", "created": "Wed, 21 Sep 2016 08:41:43 GMT" }, { "version": "v4", "created": "Tue, 8 Nov 2016 06:11:30 GMT" } ]
2016-11-09T00:00:00
[ [ "Li", "Yanghao", "" ], [ "Wang", "Naiyan", "" ], [ "Shi", "Jianping", "" ], [ "Liu", "Jiaying", "" ], [ "Hou", "Xiaodi", "" ] ]
TITLE: Revisiting Batch Normalization For Practical Domain Adaptation ABSTRACT: Deep neural networks (DNN) have shown unprecedented success in various computer vision applications such as image classification and object detection. However, it is still a common annoyance during the training phase, that one has to prepare at least thousands of labeled images to fine-tune a network to a specific domain. Recent study (Tommasi et al. 2015) shows that a DNN has strong dependency towards the training dataset, and the learned features cannot be easily transferred to a different but relevant task without fine-tuning. In this paper, we propose a simple yet powerful remedy, called Adaptive Batch Normalization (AdaBN) to increase the generalization ability of a DNN. By modulating the statistics in all Batch Normalization layers across the network, our approach achieves deep adaptation effect for domain adaptation tasks. In contrary to other deep learning domain adaptation methods, our method does not require additional components, and is parameter-free. It archives state-of-the-art performance despite its surprising simplicity. Furthermore, we demonstrate that our method is complementary with other existing methods. Combining AdaBN with existing domain adaptation treatments may further improve model performance.
no_new_dataset
0.945298
1609.05413
Camila Ara\'ujo
Gabriel Magno, Camila Souza Ara\'ujo, Wagner Meira Jr., Virgilio Almeida
Stereotypes in Search Engine Results: Understanding The Role of Local and Global Factors
null
null
null
null
cs.CY
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The internet has been blurring the lines between local and global cultures, affecting in different ways the perception of people about themselves and others. In the global context of the internet, search engine platforms are a key mediator between individuals and information. In this paper, we examine the local and global impact of the internet on the formation of female physical attractiveness stereotypes in search engine results. By investigating datasets of images collected from two major search engines in 42 countries, we identify a significant fraction of replicated images. We find that common images are clustered around countries with the same language. We also show that existence of common images among countries is practically eliminated when the queries are limited to local sites. In summary, we show evidence that results from search engines are biased towards the language used to query the system, which leads to certain attractiveness stereotypes that are often quite different from the majority of the female population of the country.
[ { "version": "v1", "created": "Sun, 18 Sep 2016 01:37:50 GMT" }, { "version": "v2", "created": "Mon, 7 Nov 2016 23:43:19 GMT" } ]
2016-11-09T00:00:00
[ [ "Magno", "Gabriel", "" ], [ "Araújo", "Camila Souza", "" ], [ "Meira", "Wagner", "Jr." ], [ "Almeida", "Virgilio", "" ] ]
TITLE: Stereotypes in Search Engine Results: Understanding The Role of Local and Global Factors ABSTRACT: The internet has been blurring the lines between local and global cultures, affecting in different ways the perception of people about themselves and others. In the global context of the internet, search engine platforms are a key mediator between individuals and information. In this paper, we examine the local and global impact of the internet on the formation of female physical attractiveness stereotypes in search engine results. By investigating datasets of images collected from two major search engines in 42 countries, we identify a significant fraction of replicated images. We find that common images are clustered around countries with the same language. We also show that existence of common images among countries is practically eliminated when the queries are limited to local sites. In summary, we show evidence that results from search engines are biased towards the language used to query the system, which leads to certain attractiveness stereotypes that are often quite different from the majority of the female population of the country.
no_new_dataset
0.944944
1611.02305
Xinran He
Xinran He, Ke Xu, David Kempe and Yan Liu
Learning Influence Functions from Incomplete Observations
Full version of paper "Learning Influence Functions from Incomplete Observations" in NIPS16
null
null
null
cs.SI cs.LG stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the problem of learning influence functions under incomplete observations of node activations. Incomplete observations are a major concern as most (online and real-world) social networks are not fully observable. We establish both proper and improper PAC learnability of influence functions under randomly missing observations. Proper PAC learnability under the Discrete-Time Linear Threshold (DLT) and Discrete-Time Independent Cascade (DIC) models is established by reducing incomplete observations to complete observations in a modified graph. Our improper PAC learnability result applies for the DLT and DIC models as well as the Continuous-Time Independent Cascade (CIC) model. It is based on a parametrization in terms of reachability features, and also gives rise to an efficient and practical heuristic. Experiments on synthetic and real-world datasets demonstrate the ability of our method to compensate even for a fairly large fraction of missing observations.
[ { "version": "v1", "created": "Mon, 7 Nov 2016 21:28:40 GMT" } ]
2016-11-09T00:00:00
[ [ "He", "Xinran", "" ], [ "Xu", "Ke", "" ], [ "Kempe", "David", "" ], [ "Liu", "Yan", "" ] ]
TITLE: Learning Influence Functions from Incomplete Observations ABSTRACT: We study the problem of learning influence functions under incomplete observations of node activations. Incomplete observations are a major concern as most (online and real-world) social networks are not fully observable. We establish both proper and improper PAC learnability of influence functions under randomly missing observations. Proper PAC learnability under the Discrete-Time Linear Threshold (DLT) and Discrete-Time Independent Cascade (DIC) models is established by reducing incomplete observations to complete observations in a modified graph. Our improper PAC learnability result applies for the DLT and DIC models as well as the Continuous-Time Independent Cascade (CIC) model. It is based on a parametrization in terms of reachability features, and also gives rise to an efficient and practical heuristic. Experiments on synthetic and real-world datasets demonstrate the ability of our method to compensate even for a fairly large fraction of missing observations.
no_new_dataset
0.946547
1611.02329
Shaunak Bopardikar
Shaunak D. Bopardikar, Alberto Speranzon, Cedric Langbort
Convergence Analysis of Iterated Best Response for a Trusted Computation Game
Contains detailed proofs of all results as well as an additional section on "the case of equal means" (Section 5)
null
null
null
cs.GT
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We introduce a game of trusted computation in which a sensor equipped with limited computing power leverages a central node to evaluate a specified function over a large dataset, collected over time. We assume that the central computer can be under attack and we propose a strategy where the sensor retains a limited amount of the data to counteract the effect of attack. We formulate the problem as a two player game in which the sensor (defender) chooses an optimal fusion strategy using both the non-trusted output from the central computer and locally stored trusted data. The attacker seeks to compromise the computation by influencing the fused value through malicious manipulation of the data stored on the central node. We first characterize all Nash equilibria of this game, which turn out to be dependent on parameters known to both players. Next we adopt an Iterated Best Response (IBR) scheme in which, at each iteration, the central computer reveals its output to the sensor, who then computes its best response based on a linear combination of its private local estimate and the untrusted third-party output. We characterize necessary and sufficient conditions for convergence of the IBR along with numerical results which show that the convergence conditions are relatively tight.
[ { "version": "v1", "created": "Mon, 7 Nov 2016 22:38:32 GMT" } ]
2016-11-09T00:00:00
[ [ "Bopardikar", "Shaunak D.", "" ], [ "Speranzon", "Alberto", "" ], [ "Langbort", "Cedric", "" ] ]
TITLE: Convergence Analysis of Iterated Best Response for a Trusted Computation Game ABSTRACT: We introduce a game of trusted computation in which a sensor equipped with limited computing power leverages a central node to evaluate a specified function over a large dataset, collected over time. We assume that the central computer can be under attack and we propose a strategy where the sensor retains a limited amount of the data to counteract the effect of attack. We formulate the problem as a two player game in which the sensor (defender) chooses an optimal fusion strategy using both the non-trusted output from the central computer and locally stored trusted data. The attacker seeks to compromise the computation by influencing the fused value through malicious manipulation of the data stored on the central node. We first characterize all Nash equilibria of this game, which turn out to be dependent on parameters known to both players. Next we adopt an Iterated Best Response (IBR) scheme in which, at each iteration, the central computer reveals its output to the sensor, who then computes its best response based on a linear combination of its private local estimate and the untrusted third-party output. We characterize necessary and sufficient conditions for convergence of the IBR along with numerical results which show that the convergence conditions are relatively tight.
no_new_dataset
0.943191
1611.02516
Miltiadis Allamanis
Miltiadis Allamanis, Earl T. Barr, Ren\'e Just, Charles Sutton
Tailored Mutants Fit Bugs Better
null
null
null
null
cs.SE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Mutation analysis measures test suite adequacy, the degree to which a test suite detects seeded faults: one test suite is better than another if it detects more mutants. Mutation analysis effectiveness rests on the assumption that mutants are coupled with real faults i.e. mutant detection is strongly correlated with real fault detection. The work that validated this also showed that a large portion of defects remain out of reach. We introduce tailored mutation operators to reach and capture these defects. Tailored mutation operators are built from and apply to an existing codebase and its history. They can, for instance, identify and replay errors specific to the project for which they are tailored. As our point of departure, we define tailored mutation operators for identifiers, which mutation analysis has largely ignored, because there are too many ways to mutate them. Evaluated on the Defects4J dataset, our new mutation operators creates mutants coupled to 14% more faults, compared to traditional mutation operators. These new mutation operators, however, quadruple the number of mutants. To combat this problem, we propose a new approach to mutant selection focusing on the location at which to apply mutation operators and the unnaturalness of the mutated code. The results demonstrate that the location selection heuristics produce mutants more closely coupled to real faults for a given budget of mutation operator applications. In summary, this paper defines and explores tailored mutation operators, advancing the state of the art in mutation testing in two ways: 1) it suggests mutation operators that mutate identifiers and literals, extending mutation analysis to a new class of faults and 2) it demonstrates that selecting the location where a mutation operator is applied decreases the number of generated mutants without affecting the coupling of mutants and real faults.
[ { "version": "v1", "created": "Tue, 8 Nov 2016 13:43:51 GMT" } ]
2016-11-09T00:00:00
[ [ "Allamanis", "Miltiadis", "" ], [ "Barr", "Earl T.", "" ], [ "Just", "René", "" ], [ "Sutton", "Charles", "" ] ]
TITLE: Tailored Mutants Fit Bugs Better ABSTRACT: Mutation analysis measures test suite adequacy, the degree to which a test suite detects seeded faults: one test suite is better than another if it detects more mutants. Mutation analysis effectiveness rests on the assumption that mutants are coupled with real faults i.e. mutant detection is strongly correlated with real fault detection. The work that validated this also showed that a large portion of defects remain out of reach. We introduce tailored mutation operators to reach and capture these defects. Tailored mutation operators are built from and apply to an existing codebase and its history. They can, for instance, identify and replay errors specific to the project for which they are tailored. As our point of departure, we define tailored mutation operators for identifiers, which mutation analysis has largely ignored, because there are too many ways to mutate them. Evaluated on the Defects4J dataset, our new mutation operators creates mutants coupled to 14% more faults, compared to traditional mutation operators. These new mutation operators, however, quadruple the number of mutants. To combat this problem, we propose a new approach to mutant selection focusing on the location at which to apply mutation operators and the unnaturalness of the mutated code. The results demonstrate that the location selection heuristics produce mutants more closely coupled to real faults for a given budget of mutation operator applications. In summary, this paper defines and explores tailored mutation operators, advancing the state of the art in mutation testing in two ways: 1) it suggests mutation operators that mutate identifiers and literals, extending mutation analysis to a new class of faults and 2) it demonstrates that selecting the location where a mutation operator is applied decreases the number of generated mutants without affecting the coupling of mutants and real faults.
no_new_dataset
0.951684
1611.02624
Vasileios Kotronis
Rowan Kloti, Bernhard Ager, Vasileios Kotronis, George Nomikos and Xenofontas Dimitropoulos
A Comparative Look into Public IXP Datasets
ACM Computer Communication Review, Vol. 46 / Issue 1, pages 21-29, 11/1/2016
null
null
null
cs.NI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Internet eXchange Points (IXPs) are core components of the Internet infrastructure where Internet Service Providers (ISPs) meet and exchange traffic. During the last few years, the number and size of IXPs have increased rapidly, driving the flattening and shortening of Internet paths. However, understanding the present status of the IXP ecosystem and its potential role in shaping the future Internet requires rigorous data about IXPs, their presence, status, participants, etc. In this work, we do the first cross-comparison of three well-known publicly available IXP databases, namely of PeeringDB, Euro-IX, and PCH. A key challenge we address is linking IXP identifiers across databases maintained by different organizations. We find different AS-centric versus IXP-centric views provided by the databases as a result of their data collection approaches. In addition, we highlight differences and similarities w.r.t. IXP participants, geographical coverage, and co-location facilities. As a side-product of our linkage heuristics, we make publicly available the union of the three databases, which includes 40.2 % more IXPs and 66.3 % more IXP participants than the commonly-used PeeringDB. We also publish our analysis code to foster reproducibility of our experiments and shed preliminary insights into the accuracy of the union dataset.
[ { "version": "v1", "created": "Tue, 8 Nov 2016 17:38:49 GMT" } ]
2016-11-09T00:00:00
[ [ "Kloti", "Rowan", "" ], [ "Ager", "Bernhard", "" ], [ "Kotronis", "Vasileios", "" ], [ "Nomikos", "George", "" ], [ "Dimitropoulos", "Xenofontas", "" ] ]
TITLE: A Comparative Look into Public IXP Datasets ABSTRACT: Internet eXchange Points (IXPs) are core components of the Internet infrastructure where Internet Service Providers (ISPs) meet and exchange traffic. During the last few years, the number and size of IXPs have increased rapidly, driving the flattening and shortening of Internet paths. However, understanding the present status of the IXP ecosystem and its potential role in shaping the future Internet requires rigorous data about IXPs, their presence, status, participants, etc. In this work, we do the first cross-comparison of three well-known publicly available IXP databases, namely of PeeringDB, Euro-IX, and PCH. A key challenge we address is linking IXP identifiers across databases maintained by different organizations. We find different AS-centric versus IXP-centric views provided by the databases as a result of their data collection approaches. In addition, we highlight differences and similarities w.r.t. IXP participants, geographical coverage, and co-location facilities. As a side-product of our linkage heuristics, we make publicly available the union of the three databases, which includes 40.2 % more IXPs and 66.3 % more IXP participants than the commonly-used PeeringDB. We also publish our analysis code to foster reproducibility of our experiments and shed preliminary insights into the accuracy of the union dataset.
no_new_dataset
0.943815
1512.01413
Katherine Bouman
Katherine L. Bouman, Michael D. Johnson, Daniel Zoran, Vincent L. Fish, Sheperd S. Doeleman, William T. Freeman
Computational Imaging for VLBI Image Reconstruction
Accepted for publication at CVPR 2016, Project Website: http://vlbiimaging.csail.mit.edu/, Video of Oral Presentation at CVPR June 2016: https://www.youtube.com/watch?v=YgB6o_d4tL8
IEEE Conference on Computer Vision and Pattern Recognition (CVPR), 2016, pp. 913-922
null
null
astro-ph.IM astro-ph.GA cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Very long baseline interferometry (VLBI) is a technique for imaging celestial radio emissions by simultaneously observing a source from telescopes distributed across Earth. The challenges in reconstructing images from fine angular resolution VLBI data are immense. The data is extremely sparse and noisy, thus requiring statistical image models such as those designed in the computer vision community. In this paper we present a novel Bayesian approach for VLBI image reconstruction. While other methods often require careful tuning and parameter selection for different types of data, our method (CHIRP) produces good results under different settings such as low SNR or extended emission. The success of our method is demonstrated on realistic synthetic experiments as well as publicly available real data. We present this problem in a way that is accessible to members of the community, and provide a dataset website (vlbiimaging.csail.mit.edu) that facilitates controlled comparisons across algorithms.
[ { "version": "v1", "created": "Fri, 4 Dec 2015 14:11:46 GMT" }, { "version": "v2", "created": "Mon, 7 Nov 2016 15:57:40 GMT" } ]
2016-11-08T00:00:00
[ [ "Bouman", "Katherine L.", "" ], [ "Johnson", "Michael D.", "" ], [ "Zoran", "Daniel", "" ], [ "Fish", "Vincent L.", "" ], [ "Doeleman", "Sheperd S.", "" ], [ "Freeman", "William T.", "" ] ]
TITLE: Computational Imaging for VLBI Image Reconstruction ABSTRACT: Very long baseline interferometry (VLBI) is a technique for imaging celestial radio emissions by simultaneously observing a source from telescopes distributed across Earth. The challenges in reconstructing images from fine angular resolution VLBI data are immense. The data is extremely sparse and noisy, thus requiring statistical image models such as those designed in the computer vision community. In this paper we present a novel Bayesian approach for VLBI image reconstruction. While other methods often require careful tuning and parameter selection for different types of data, our method (CHIRP) produces good results under different settings such as low SNR or extended emission. The success of our method is demonstrated on realistic synthetic experiments as well as publicly available real data. We present this problem in a way that is accessible to members of the community, and provide a dataset website (vlbiimaging.csail.mit.edu) that facilitates controlled comparisons across algorithms.
new_dataset
0.856632
1602.01517
Keiller Nogueira
Keiller Nogueira, Ot\'avio A. B. Penatti, Jefersson A. dos Santos
Towards Better Exploiting Convolutional Neural Networks for Remote Sensing Scene Classification
null
null
10.1016/j.patcog.2016.07.001
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present an analysis of three possible strategies for exploiting the power of existing convolutional neural networks (ConvNets) in different scenarios from the ones they were trained: full training, fine tuning, and using ConvNets as feature extractors. In many applications, especially including remote sensing, it is not feasible to fully design and train a new ConvNet, as this usually requires a considerable amount of labeled data and demands high computational costs. Therefore, it is important to understand how to obtain the best profit from existing ConvNets. We perform experiments with six popular ConvNets using three remote sensing datasets. We also compare ConvNets in each strategy with existing descriptors and with state-of-the-art baselines. Results point that fine tuning tends to be the best performing strategy. In fact, using the features from the fine-tuned ConvNet with linear SVM obtains the best results. We also achieved state-of-the-art results for the three datasets used.
[ { "version": "v1", "created": "Thu, 4 Feb 2016 00:53:32 GMT" } ]
2016-11-08T00:00:00
[ [ "Nogueira", "Keiller", "" ], [ "Penatti", "Otávio A. B.", "" ], [ "Santos", "Jefersson A. dos", "" ] ]
TITLE: Towards Better Exploiting Convolutional Neural Networks for Remote Sensing Scene Classification ABSTRACT: We present an analysis of three possible strategies for exploiting the power of existing convolutional neural networks (ConvNets) in different scenarios from the ones they were trained: full training, fine tuning, and using ConvNets as feature extractors. In many applications, especially including remote sensing, it is not feasible to fully design and train a new ConvNet, as this usually requires a considerable amount of labeled data and demands high computational costs. Therefore, it is important to understand how to obtain the best profit from existing ConvNets. We perform experiments with six popular ConvNets using three remote sensing datasets. We also compare ConvNets in each strategy with existing descriptors and with state-of-the-art baselines. Results point that fine tuning tends to be the best performing strategy. In fact, using the features from the fine-tuned ConvNet with linear SVM obtains the best results. We also achieved state-of-the-art results for the three datasets used.
no_new_dataset
0.951818
1606.01865
Zhengping Che
Zhengping Che, Sanjay Purushotham, Kyunghyun Cho, David Sontag, Yan Liu
Recurrent Neural Networks for Multivariate Time Series with Missing Values
null
null
null
null
cs.LG cs.NE stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Multivariate time series data in practical applications, such as health care, geoscience, and biology, are characterized by a variety of missing values. In time series prediction and other related tasks, it has been noted that missing values and their missing patterns are often correlated with the target labels, a.k.a., informative missingness. There is very limited work on exploiting the missing patterns for effective imputation and improving prediction performance. In this paper, we develop novel deep learning models, namely GRU-D, as one of the early attempts. GRU-D is based on Gated Recurrent Unit (GRU), a state-of-the-art recurrent neural network. It takes two representations of missing patterns, i.e., masking and time interval, and effectively incorporates them into a deep model architecture so that it not only captures the long-term temporal dependencies in time series, but also utilizes the missing patterns to achieve better prediction results. Experiments of time series classification tasks on real-world clinical datasets (MIMIC-III, PhysioNet) and synthetic datasets demonstrate that our models achieve state-of-the-art performance and provides useful insights for better understanding and utilization of missing values in time series analysis.
[ { "version": "v1", "created": "Mon, 6 Jun 2016 19:08:41 GMT" }, { "version": "v2", "created": "Mon, 7 Nov 2016 20:51:29 GMT" } ]
2016-11-08T00:00:00
[ [ "Che", "Zhengping", "" ], [ "Purushotham", "Sanjay", "" ], [ "Cho", "Kyunghyun", "" ], [ "Sontag", "David", "" ], [ "Liu", "Yan", "" ] ]
TITLE: Recurrent Neural Networks for Multivariate Time Series with Missing Values ABSTRACT: Multivariate time series data in practical applications, such as health care, geoscience, and biology, are characterized by a variety of missing values. In time series prediction and other related tasks, it has been noted that missing values and their missing patterns are often correlated with the target labels, a.k.a., informative missingness. There is very limited work on exploiting the missing patterns for effective imputation and improving prediction performance. In this paper, we develop novel deep learning models, namely GRU-D, as one of the early attempts. GRU-D is based on Gated Recurrent Unit (GRU), a state-of-the-art recurrent neural network. It takes two representations of missing patterns, i.e., masking and time interval, and effectively incorporates them into a deep model architecture so that it not only captures the long-term temporal dependencies in time series, but also utilizes the missing patterns to achieve better prediction results. Experiments of time series classification tasks on real-world clinical datasets (MIMIC-III, PhysioNet) and synthetic datasets demonstrate that our models achieve state-of-the-art performance and provides useful insights for better understanding and utilization of missing values in time series analysis.
no_new_dataset
0.948394
1608.07905
Shuohang Wang
Shuohang Wang and Jing Jiang
Machine Comprehension Using Match-LSTM and Answer Pointer
11 pages; 3 figures
null
null
null
cs.CL cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Machine comprehension of text is an important problem in natural language processing. A recently released dataset, the Stanford Question Answering Dataset (SQuAD), offers a large number of real questions and their answers created by humans through crowdsourcing. SQuAD provides a challenging testbed for evaluating machine comprehension algorithms, partly because compared with previous datasets, in SQuAD the answers do not come from a small set of candidate answers and they have variable lengths. We propose an end-to-end neural architecture for the task. The architecture is based on match-LSTM, a model we proposed previously for textual entailment, and Pointer Net, a sequence-to-sequence model proposed by Vinyals et al.(2015) to constrain the output tokens to be from the input sequences. We propose two ways of using Pointer Net for our task. Our experiments show that both of our two models substantially outperform the best results obtained by Rajpurkar et al.(2016) using logistic regression and manually crafted features.
[ { "version": "v1", "created": "Mon, 29 Aug 2016 03:42:50 GMT" }, { "version": "v2", "created": "Mon, 7 Nov 2016 03:39:40 GMT" } ]
2016-11-08T00:00:00
[ [ "Wang", "Shuohang", "" ], [ "Jiang", "Jing", "" ] ]
TITLE: Machine Comprehension Using Match-LSTM and Answer Pointer ABSTRACT: Machine comprehension of text is an important problem in natural language processing. A recently released dataset, the Stanford Question Answering Dataset (SQuAD), offers a large number of real questions and their answers created by humans through crowdsourcing. SQuAD provides a challenging testbed for evaluating machine comprehension algorithms, partly because compared with previous datasets, in SQuAD the answers do not come from a small set of candidate answers and they have variable lengths. We propose an end-to-end neural architecture for the task. The architecture is based on match-LSTM, a model we proposed previously for textual entailment, and Pointer Net, a sequence-to-sequence model proposed by Vinyals et al.(2015) to constrain the output tokens to be from the input sequences. We propose two ways of using Pointer Net for our task. Our experiments show that both of our two models substantially outperform the best results obtained by Rajpurkar et al.(2016) using logistic regression and manually crafted features.
new_dataset
0.948489
1610.04900
Cheng Tang
Cheng Tang, Claire Monteleoni
Convergence rate of stochastic k-means
null
null
null
null
cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We analyze online and mini-batch k-means variants. Both scale up the widely used Lloyd 's algorithm via stochastic approximation, and have become popular for large-scale clustering and unsupervised feature learning. We show, for the first time, that they have global convergence towards local optima at $O(\frac{1}{t})$ rate under general conditions. In addition, we show if the dataset is clusterable, with suitable initialization, mini-batch k-means converges to an optimal k-means solution with $O(\frac{1}{t})$ convergence rate with high probability. The k-means objective is non-convex and non-differentiable: we exploit ideas from non-convex gradient-based optimization by providing a novel characterization of the trajectory of k-means algorithm on its solution space, and circumvent its non-differentiability via geometric insights about k-means update.
[ { "version": "v1", "created": "Sun, 16 Oct 2016 18:59:59 GMT" }, { "version": "v2", "created": "Mon, 7 Nov 2016 18:20:06 GMT" } ]
2016-11-08T00:00:00
[ [ "Tang", "Cheng", "" ], [ "Monteleoni", "Claire", "" ] ]
TITLE: Convergence rate of stochastic k-means ABSTRACT: We analyze online and mini-batch k-means variants. Both scale up the widely used Lloyd 's algorithm via stochastic approximation, and have become popular for large-scale clustering and unsupervised feature learning. We show, for the first time, that they have global convergence towards local optima at $O(\frac{1}{t})$ rate under general conditions. In addition, we show if the dataset is clusterable, with suitable initialization, mini-batch k-means converges to an optimal k-means solution with $O(\frac{1}{t})$ convergence rate with high probability. The k-means objective is non-convex and non-differentiable: we exploit ideas from non-convex gradient-based optimization by providing a novel characterization of the trajectory of k-means algorithm on its solution space, and circumvent its non-differentiability via geometric insights about k-means update.
no_new_dataset
0.945701
1611.01586
Gang Niu
Marthinus C. du Plessis, Gang Niu, and Masashi Sugiyama
Class-prior Estimation for Learning from Positive and Unlabeled Data
To appear in Machine Learning
null
10.1007/s10994-016-5604-6
null
cs.LG stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the problem of estimating the class prior in an unlabeled dataset. Under the assumption that an additional labeled dataset is available, the class prior can be estimated by fitting a mixture of class-wise data distributions to the unlabeled data distribution. However, in practice, such an additional labeled dataset is often not available. In this paper, we show that, with additional samples coming only from the positive class, the class prior of the unlabeled dataset can be estimated correctly. Our key idea is to use properly penalized divergences for model fitting to cancel the error caused by the absence of negative samples. We further show that the use of the penalized $L_1$-distance gives a computationally efficient algorithm with an analytic solution. The consistency, stability, and estimation error are theoretically analyzed. Finally, we experimentally demonstrate the usefulness of the proposed method.
[ { "version": "v1", "created": "Sat, 5 Nov 2016 01:58:12 GMT" } ]
2016-11-08T00:00:00
[ [ "Plessis", "Marthinus C. du", "" ], [ "Niu", "Gang", "" ], [ "Sugiyama", "Masashi", "" ] ]
TITLE: Class-prior Estimation for Learning from Positive and Unlabeled Data ABSTRACT: We consider the problem of estimating the class prior in an unlabeled dataset. Under the assumption that an additional labeled dataset is available, the class prior can be estimated by fitting a mixture of class-wise data distributions to the unlabeled data distribution. However, in practice, such an additional labeled dataset is often not available. In this paper, we show that, with additional samples coming only from the positive class, the class prior of the unlabeled dataset can be estimated correctly. Our key idea is to use properly penalized divergences for model fitting to cancel the error caused by the absence of negative samples. We further show that the use of the penalized $L_1$-distance gives a computationally efficient algorithm with an analytic solution. The consistency, stability, and estimation error are theoretically analyzed. Finally, we experimentally demonstrate the usefulness of the proposed method.
no_new_dataset
0.943764
1611.01640
Jiedong Hao
Jiedong Hao, Jing Dong, Wei Wang, Tieniu Tan
What Is the Best Practice for CNNs Applied to Visual Instance Retrieval?
The verison submitted to ICLR
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Previous work has shown that feature maps of deep convolutional neural networks (CNNs) can be interpreted as feature representation of a particular image region. Features aggregated from these feature maps have been exploited for image retrieval tasks and achieved state-of-the-art performances in recent years. The key to the success of such methods is the feature representation. However, the different factors that impact the effectiveness of features are still not explored thoroughly. There are much less discussion about the best combination of them. The main contribution of our paper is the thorough evaluations of the various factors that affect the discriminative ability of the features extracted from CNNs. Based on the evaluation results, we also identify the best choices for different factors and propose a new multi-scale image feature representation method to encode the image effectively. Finally, we show that the proposed method generalises well and outperforms the state-of-the-art methods on four typical datasets used for visual instance retrieval.
[ { "version": "v1", "created": "Sat, 5 Nov 2016 12:44:40 GMT" } ]
2016-11-08T00:00:00
[ [ "Hao", "Jiedong", "" ], [ "Dong", "Jing", "" ], [ "Wang", "Wei", "" ], [ "Tan", "Tieniu", "" ] ]
TITLE: What Is the Best Practice for CNNs Applied to Visual Instance Retrieval? ABSTRACT: Previous work has shown that feature maps of deep convolutional neural networks (CNNs) can be interpreted as feature representation of a particular image region. Features aggregated from these feature maps have been exploited for image retrieval tasks and achieved state-of-the-art performances in recent years. The key to the success of such methods is the feature representation. However, the different factors that impact the effectiveness of features are still not explored thoroughly. There are much less discussion about the best combination of them. The main contribution of our paper is the thorough evaluations of the various factors that affect the discriminative ability of the features extracted from CNNs. Based on the evaluation results, we also identify the best choices for different factors and propose a new multi-scale image feature representation method to encode the image effectively. Finally, we show that the proposed method generalises well and outperforms the state-of-the-art methods on four typical datasets used for visual instance retrieval.
no_new_dataset
0.9455
1611.01646
Ting Yao
Ting Yao, Yingwei Pan, Yehao Li, Zhaofan Qiu, Tao Mei
Boosting Image Captioning with Attributes
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Automatically describing an image with a natural language has been an emerging challenge in both fields of computer vision and natural language processing. In this paper, we present Long Short-Term Memory with Attributes (LSTM-A) - a novel architecture that integrates attributes into the successful Convolutional Neural Networks (CNNs) plus Recurrent Neural Networks (RNNs) image captioning framework, by training them in an end-to-end manner. To incorporate attributes, we construct variants of architectures by feeding image representations and attributes into RNNs in different ways to explore the mutual but also fuzzy relationship between them. Extensive experiments are conducted on COCO image captioning dataset and our framework achieves superior results when compared to state-of-the-art deep models. Most remarkably, we obtain METEOR/CIDEr-D of 25.2%/98.6% on testing data of widely used and publicly available splits in (Karpathy & Fei-Fei, 2015) when extracting image representations by GoogleNet and achieve to date top-1 performance on COCO captioning Leaderboard.
[ { "version": "v1", "created": "Sat, 5 Nov 2016 13:12:29 GMT" } ]
2016-11-08T00:00:00
[ [ "Yao", "Ting", "" ], [ "Pan", "Yingwei", "" ], [ "Li", "Yehao", "" ], [ "Qiu", "Zhaofan", "" ], [ "Mei", "Tao", "" ] ]
TITLE: Boosting Image Captioning with Attributes ABSTRACT: Automatically describing an image with a natural language has been an emerging challenge in both fields of computer vision and natural language processing. In this paper, we present Long Short-Term Memory with Attributes (LSTM-A) - a novel architecture that integrates attributes into the successful Convolutional Neural Networks (CNNs) plus Recurrent Neural Networks (RNNs) image captioning framework, by training them in an end-to-end manner. To incorporate attributes, we construct variants of architectures by feeding image representations and attributes into RNNs in different ways to explore the mutual but also fuzzy relationship between them. Extensive experiments are conducted on COCO image captioning dataset and our framework achieves superior results when compared to state-of-the-art deep models. Most remarkably, we obtain METEOR/CIDEr-D of 25.2%/98.6% on testing data of widely used and publicly available splits in (Karpathy & Fei-Fei, 2015) when extracting image representations by GoogleNet and achieve to date top-1 performance on COCO captioning Leaderboard.
no_new_dataset
0.949482
1611.01726
Gyuwan Kim
Gyuwan Kim, Hayoon Yi, Jangho Lee, Yunheung Paek, Sungroh Yoon
LSTM-Based System-Call Language Modeling and Robust Ensemble Method for Designing Host-Based Intrusion Detection Systems
12 pages, 5 figures
null
null
null
cs.CR cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In computer security, designing a robust intrusion detection system is one of the most fundamental and important problems. In this paper, we propose a system-call language-modeling approach for designing anomaly-based host intrusion detection systems. To remedy the issue of high false-alarm rates commonly arising in conventional methods, we employ a novel ensemble method that blends multiple thresholding classifiers into a single one, making it possible to accumulate 'highly normal' sequences. The proposed system-call language model has various advantages leveraged by the fact that it can learn the semantic meaning and interactions of each system call that existing methods cannot effectively consider. Through diverse experiments on public benchmark datasets, we demonstrate the validity and effectiveness of the proposed method. Moreover, we show that our model possesses high portability, which is one of the key aspects of realizing successful intrusion detection systems.
[ { "version": "v1", "created": "Sun, 6 Nov 2016 04:07:29 GMT" } ]
2016-11-08T00:00:00
[ [ "Kim", "Gyuwan", "" ], [ "Yi", "Hayoon", "" ], [ "Lee", "Jangho", "" ], [ "Paek", "Yunheung", "" ], [ "Yoon", "Sungroh", "" ] ]
TITLE: LSTM-Based System-Call Language Modeling and Robust Ensemble Method for Designing Host-Based Intrusion Detection Systems ABSTRACT: In computer security, designing a robust intrusion detection system is one of the most fundamental and important problems. In this paper, we propose a system-call language-modeling approach for designing anomaly-based host intrusion detection systems. To remedy the issue of high false-alarm rates commonly arising in conventional methods, we employ a novel ensemble method that blends multiple thresholding classifiers into a single one, making it possible to accumulate 'highly normal' sequences. The proposed system-call language model has various advantages leveraged by the fact that it can learn the semantic meaning and interactions of each system call that existing methods cannot effectively consider. Through diverse experiments on public benchmark datasets, we demonstrate the validity and effectiveness of the proposed method. Moreover, we show that our model possesses high portability, which is one of the key aspects of realizing successful intrusion detection systems.
no_new_dataset
0.94474
1611.01747
Shuohang Wang
Shuohang Wang and Jing Jiang
A Compare-Aggregate Model for Matching Text Sequences
11 pages, 2 figures
null
null
null
cs.CL cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Many NLP tasks including machine comprehension, answer selection and text entailment require the comparison between sequences. Matching the important units between sequences is a key to solve these problems. In this paper, we present a general "compare-aggregate" framework that performs word-level matching followed by aggregation using Convolutional Neural Networks. We particularly focus on the different comparison functions we can use to match two vectors. We use four different datasets to evaluate the model. We find that some simple comparison functions based on element-wise operations can work better than standard neural network and neural tensor network.
[ { "version": "v1", "created": "Sun, 6 Nov 2016 09:50:24 GMT" } ]
2016-11-08T00:00:00
[ [ "Wang", "Shuohang", "" ], [ "Jiang", "Jing", "" ] ]
TITLE: A Compare-Aggregate Model for Matching Text Sequences ABSTRACT: Many NLP tasks including machine comprehension, answer selection and text entailment require the comparison between sequences. Matching the important units between sequences is a key to solve these problems. In this paper, we present a general "compare-aggregate" framework that performs word-level matching followed by aggregation using Convolutional Neural Networks. We particularly focus on the different comparison functions we can use to match two vectors. We use four different datasets to evaluate the model. We find that some simple comparison functions based on element-wise operations can work better than standard neural network and neural tensor network.
no_new_dataset
0.94474
1611.01783
Joseph Keshet
Yehoshua Dissen, Joseph Keshet, Jacob Goldberger and Cynthia Clopper
Domain Adaptation For Formant Estimation Using Deep Learning
null
null
null
null
cs.CL cs.SD
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we present a domain adaptation technique for formant estimation using a deep network. We first train a deep learning network on a small read speech dataset. We then freeze the parameters of the trained network and use several different datasets to train an adaptation layer that makes the obtained network universal in the sense that it works well for a variety of speakers and speech domains with very different characteristics. We evaluated our adapted network on three datasets, each of which has different speaker characteristics and speech styles. The performance of our method compares favorably with alternative methods for formant estimation.
[ { "version": "v1", "created": "Sun, 6 Nov 2016 14:00:14 GMT" } ]
2016-11-08T00:00:00
[ [ "Dissen", "Yehoshua", "" ], [ "Keshet", "Joseph", "" ], [ "Goldberger", "Jacob", "" ], [ "Clopper", "Cynthia", "" ] ]
TITLE: Domain Adaptation For Formant Estimation Using Deep Learning ABSTRACT: In this paper we present a domain adaptation technique for formant estimation using a deep network. We first train a deep learning network on a small read speech dataset. We then freeze the parameters of the trained network and use several different datasets to train an adaptation layer that makes the obtained network universal in the sense that it works well for a variety of speakers and speech domains with very different characteristics. We evaluated our adapted network on three datasets, each of which has different speaker characteristics and speech styles. The performance of our method compares favorably with alternative methods for formant estimation.
no_new_dataset
0.949716
1611.01820
Behnam Ghavimi
Behnam Ghavimi (1,2), Philipp Mayr (1), Christoph Lange (2,3), Sahar Vahdati (2) and S\"oren AUER (2,3) ((1) GESIS Leibniz Institute for the Social Sciences, (2) Enterprise Information Systems (EIS), University of Bonn, (3) Fraunhofer Institute for Intelligent Analysis and Information Systems IAIS)
A Semi-Automatic Approach for Detecting Dataset References in Social Science Texts
Pre-print IS&U journal. arXiv admin note: substantial text overlap with arXiv:1603.01774
null
null
null
cs.DL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Today, full-texts of scientific articles are often stored in different locations than the used datasets. Dataset registries aim at a closer integration by making datasets citable but authors typically refer to datasets using inconsistent abbreviations and heterogeneous metadata (e.g. title, publication year). It is thus hard to reproduce research results, to access datasets for further analysis, and to determine the impact of a dataset. Manually detecting references to datasets in scientific articles is time-consuming and requires expert knowledge in the underlying research domain.We propose and evaluate a semi-automatic three-step approach for finding explicit references to datasets in social sciences articles.We first extract pre-defined special features from dataset titles in the da|ra registry, then detect references to datasets using the extracted features, and finally match the references found with corresponding dataset titles. The approach does not require a corpus of articles (avoiding the cold start problem) and performs well on a test corpus. We achieved an F-measure of 0.84 for detecting references in full-texts and an F-measure of 0.83 for finding correct matches of detected references in the da|ra dataset registry.
[ { "version": "v1", "created": "Sun, 6 Nov 2016 18:36:16 GMT" } ]
2016-11-08T00:00:00
[ [ "Ghavimi", "Behnam", "" ], [ "Mayr", "Philipp", "" ], [ "Lange", "Christoph", "" ], [ "Vahdati", "Sahar", "" ], [ "AUER", "Sören", "" ] ]
TITLE: A Semi-Automatic Approach for Detecting Dataset References in Social Science Texts ABSTRACT: Today, full-texts of scientific articles are often stored in different locations than the used datasets. Dataset registries aim at a closer integration by making datasets citable but authors typically refer to datasets using inconsistent abbreviations and heterogeneous metadata (e.g. title, publication year). It is thus hard to reproduce research results, to access datasets for further analysis, and to determine the impact of a dataset. Manually detecting references to datasets in scientific articles is time-consuming and requires expert knowledge in the underlying research domain.We propose and evaluate a semi-automatic three-step approach for finding explicit references to datasets in social sciences articles.We first extract pre-defined special features from dataset titles in the da|ra registry, then detect references to datasets using the extracted features, and finally match the references found with corresponding dataset titles. The approach does not require a corpus of articles (avoiding the cold start problem) and performs well on a test corpus. We achieved an F-measure of 0.84 for detecting references in full-texts and an F-measure of 0.83 for finding correct matches of detected references in the da|ra dataset registry.
no_new_dataset
0.949995
1611.01867
Xinyun Chen
Xinyun Chen, Chang Liu, Richard Shin, Dawn Song, Mingcheng Chen
Latent Attention For If-Then Program Synthesis
Accepted by NIPS 2016
null
null
null
cs.CL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Automatic translation from natural language descriptions into programs is a longstanding challenging problem. In this work, we consider a simple yet important sub-problem: translation from textual descriptions to If-Then programs. We devise a novel neural network architecture for this task which we train end-to-end. Specifically, we introduce Latent Attention, which computes multiplicative weights for the words in the description in a two-stage process with the goal of better leveraging the natural language structures that indicate the relevant parts for predicting program elements. Our architecture reduces the error rate by 28.57% compared to prior art. We also propose a one-shot learning scenario of If-Then program synthesis and simulate it with our existing dataset. We demonstrate a variation on the training procedure for this scenario that outperforms the original procedure, significantly closing the gap to the model trained with all data.
[ { "version": "v1", "created": "Mon, 7 Nov 2016 00:56:19 GMT" } ]
2016-11-08T00:00:00
[ [ "Chen", "Xinyun", "" ], [ "Liu", "Chang", "" ], [ "Shin", "Richard", "" ], [ "Song", "Dawn", "" ], [ "Chen", "Mingcheng", "" ] ]
TITLE: Latent Attention For If-Then Program Synthesis ABSTRACT: Automatic translation from natural language descriptions into programs is a longstanding challenging problem. In this work, we consider a simple yet important sub-problem: translation from textual descriptions to If-Then programs. We devise a novel neural network architecture for this task which we train end-to-end. Specifically, we introduce Latent Attention, which computes multiplicative weights for the words in the description in a two-stage process with the goal of better leveraging the natural language structures that indicate the relevant parts for predicting program elements. Our architecture reduces the error rate by 28.57% compared to prior art. We also propose a one-shot learning scenario of If-Then program synthesis and simulate it with our existing dataset. We demonstrate a variation on the training procedure for this scenario that outperforms the original procedure, significantly closing the gap to the model trained with all data.
no_new_dataset
0.803097
1611.01872
Ye Liu
Ye Liu, Liqiang Nie, Lei Han, Luming Zhang, David S Rosenblum
Action2Activity: Recognizing Complex Activities from Sensor Data
IJCAI 2015
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
As compared to simple actions, activities are much more complex, but semantically consistent with a human's real life. Techniques for action recognition from sensor generated data are mature. However, there has been relatively little work on bridging the gap between actions and activities. To this end, this paper presents a novel approach for complex activity recognition comprising of two components. The first component is temporal pattern mining, which provides a mid-level feature representation for activities, encodes temporal relatedness among actions, and captures the intrinsic properties of activities. The second component is adaptive Multi-Task Learning, which captures relatedness among activities and selects discriminant features. Extensive experiments on a real-world dataset demonstrate the effectiveness of our work.
[ { "version": "v1", "created": "Mon, 7 Nov 2016 02:01:29 GMT" } ]
2016-11-08T00:00:00
[ [ "Liu", "Ye", "" ], [ "Nie", "Liqiang", "" ], [ "Han", "Lei", "" ], [ "Zhang", "Luming", "" ], [ "Rosenblum", "David S", "" ] ]
TITLE: Action2Activity: Recognizing Complex Activities from Sensor Data ABSTRACT: As compared to simple actions, activities are much more complex, but semantically consistent with a human's real life. Techniques for action recognition from sensor generated data are mature. However, there has been relatively little work on bridging the gap between actions and activities. To this end, this paper presents a novel approach for complex activity recognition comprising of two components. The first component is temporal pattern mining, which provides a mid-level feature representation for activities, encodes temporal relatedness among actions, and captures the intrinsic properties of activities. The second component is adaptive Multi-Task Learning, which captures relatedness among activities and selects discriminant features. Extensive experiments on a real-world dataset demonstrate the effectiveness of our work.
no_new_dataset
0.948537
1611.01964
Kalina Jasinska
Kalina Jasinska, Nikos Karampatziakis
Log-time and Log-space Extreme Classification
null
null
null
null
cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present LTLS, a technique for multiclass and multilabel prediction that can perform training and inference in logarithmic time and space. LTLS embeds large classification problems into simple structured prediction problems and relies on efficient dynamic programming algorithms for inference. We train LTLS with stochastic gradient descent on a number of multiclass and multilabel datasets and show that despite its small memory footprint it is often competitive with existing approaches.
[ { "version": "v1", "created": "Mon, 7 Nov 2016 10:10:43 GMT" } ]
2016-11-08T00:00:00
[ [ "Jasinska", "Kalina", "" ], [ "Karampatziakis", "Nikos", "" ] ]
TITLE: Log-time and Log-space Extreme Classification ABSTRACT: We present LTLS, a technique for multiclass and multilabel prediction that can perform training and inference in logarithmic time and space. LTLS embeds large classification problems into simple structured prediction problems and relies on efficient dynamic programming algorithms for inference. We train LTLS with stochastic gradient descent on a number of multiclass and multilabel datasets and show that despite its small memory footprint it is often competitive with existing approaches.
no_new_dataset
0.945801
1611.02007
Florian Boudin
Adrien Bougouin, Florian Boudin, B\'eatrice Daille
Keyphrase Annotation with Graph Co-Ranking
Accepted at the COLING 2016 conference
null
null
null
cs.CL
http://creativecommons.org/licenses/by/4.0/
Keyphrase annotation is the task of identifying textual units that represent the main content of a document. Keyphrase annotation is either carried out by extracting the most important phrases from a document, keyphrase extraction, or by assigning entries from a controlled domain-specific vocabulary, keyphrase assignment. Assignment methods are generally more reliable. They provide better-formed keyphrases, as well as keyphrases that do not occur in the document. But they are often silent on the contrary of extraction methods that do not depend on manually built resources. This paper proposes a new method to perform both keyphrase extraction and keyphrase assignment in an integrated and mutual reinforcing manner. Experiments have been carried out on datasets covering different domains of humanities and social sciences. They show statistically significant improvements compared to both keyphrase extraction and keyphrase assignment state-of-the art methods.
[ { "version": "v1", "created": "Mon, 7 Nov 2016 12:08:13 GMT" } ]
2016-11-08T00:00:00
[ [ "Bougouin", "Adrien", "" ], [ "Boudin", "Florian", "" ], [ "Daille", "Béatrice", "" ] ]
TITLE: Keyphrase Annotation with Graph Co-Ranking ABSTRACT: Keyphrase annotation is the task of identifying textual units that represent the main content of a document. Keyphrase annotation is either carried out by extracting the most important phrases from a document, keyphrase extraction, or by assigning entries from a controlled domain-specific vocabulary, keyphrase assignment. Assignment methods are generally more reliable. They provide better-formed keyphrases, as well as keyphrases that do not occur in the document. But they are often silent on the contrary of extraction methods that do not depend on manually built resources. This paper proposes a new method to perform both keyphrase extraction and keyphrase assignment in an integrated and mutual reinforcing manner. Experiments have been carried out on datasets covering different domains of humanities and social sciences. They show statistically significant improvements compared to both keyphrase extraction and keyphrase assignment state-of-the art methods.
no_new_dataset
0.950549
1611.02025
Xavier Holt
Xavier Holt, Will Radford, Ben Hachey
Presenting a New Dataset for the Timeline Generation Problem
null
null
null
null
cs.CL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The timeline generation task summarises an entity's biography by selecting stories representing key events from a large pool of relevant documents. This paper addresses the lack of a standard dataset and evaluative methodology for the problem. We present and make publicly available a new dataset of 18,793 news articles covering 39 entities. For each entity, we provide a gold standard timeline and a set of entity-related articles. We propose ROUGE as an evaluation metric and validate our dataset by showing that top Google results outperform straw-man baselines.
[ { "version": "v1", "created": "Mon, 7 Nov 2016 12:47:25 GMT" } ]
2016-11-08T00:00:00
[ [ "Holt", "Xavier", "" ], [ "Radford", "Will", "" ], [ "Hachey", "Ben", "" ] ]
TITLE: Presenting a New Dataset for the Timeline Generation Problem ABSTRACT: The timeline generation task summarises an entity's biography by selecting stories representing key events from a large pool of relevant documents. This paper addresses the lack of a standard dataset and evaluative methodology for the problem. We present and make publicly available a new dataset of 18,793 news articles covering 39 entities. For each entity, we provide a gold standard timeline and a set of entity-related articles. We propose ROUGE as an evaluation metric and validate our dataset by showing that top Google results outperform straw-man baselines.
new_dataset
0.957198
1611.02053
Andrey Filchenkov
Valeria Efimova, Andrey Filchenkov, Anatoly Shalyto
Reinforcement-based Simultaneous Algorithm and its Hyperparameters Selection
null
null
null
null
cs.LG cs.AI stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Many algorithms for data analysis exist, especially for classification problems. To solve a data analysis problem, a proper algorithm should be chosen, and also its hyperparameters should be selected. In this paper, we present a new method for the simultaneous selection of an algorithm and its hyperparameters. In order to do so, we reduced this problem to the multi-armed bandit problem. We consider an algorithm as an arm and algorithm hyperparameters search during a fixed time as the corresponding arm play. We also suggest a problem-specific reward function. We performed the experiments on 10 real datasets and compare the suggested method with the existing one implemented in Auto-WEKA. The results show that our method is significantly better in most of the cases and never worse than the Auto-WEKA.
[ { "version": "v1", "created": "Mon, 7 Nov 2016 13:55:00 GMT" } ]
2016-11-08T00:00:00
[ [ "Efimova", "Valeria", "" ], [ "Filchenkov", "Andrey", "" ], [ "Shalyto", "Anatoly", "" ] ]
TITLE: Reinforcement-based Simultaneous Algorithm and its Hyperparameters Selection ABSTRACT: Many algorithms for data analysis exist, especially for classification problems. To solve a data analysis problem, a proper algorithm should be chosen, and also its hyperparameters should be selected. In this paper, we present a new method for the simultaneous selection of an algorithm and its hyperparameters. In order to do so, we reduced this problem to the multi-armed bandit problem. We consider an algorithm as an arm and algorithm hyperparameters search during a fixed time as the corresponding arm play. We also suggest a problem-specific reward function. We performed the experiments on 10 real datasets and compare the suggested method with the existing one implemented in Auto-WEKA. The results show that our method is significantly better in most of the cases and never worse than the Auto-WEKA.
no_new_dataset
0.956756
1611.02118
Yann-A\"el Le Borgne
Yann-A\"el Le Borgne, Adriana Homolova, Gianluca Bontempi
OpenTED Browser: Insights into European Public Spendings
ECML, PKDD, SoGood workshop 2016
null
null
null
cs.CY
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present the OpenTED browser, a Web application allowing to interactively browse public spending data related to public procurements in the European Union. The application relies on Open Data recently published by the European Commission and the Publications Office of the European Union, from which we imported a curated dataset of 4.2 million contract award notices spanning the period 2006-2015. The application is designed to easily filter notices and visualise relationships between public contracting authorities and private contractors. The simple design allows for example to quickly find information about who the biggest suppliers of local governments are, and the nature of the contracted goods and services. We believe the tool, which we make Open Source, is a valuable source of information for journalists, NGOs, analysts and citizens for getting information on public procurement data, from large scale trends to local municipal developments.
[ { "version": "v1", "created": "Fri, 16 Sep 2016 14:35:16 GMT" } ]
2016-11-08T00:00:00
[ [ "Borgne", "Yann-Aël Le", "" ], [ "Homolova", "Adriana", "" ], [ "Bontempi", "Gianluca", "" ] ]
TITLE: OpenTED Browser: Insights into European Public Spendings ABSTRACT: We present the OpenTED browser, a Web application allowing to interactively browse public spending data related to public procurements in the European Union. The application relies on Open Data recently published by the European Commission and the Publications Office of the European Union, from which we imported a curated dataset of 4.2 million contract award notices spanning the period 2006-2015. The application is designed to easily filter notices and visualise relationships between public contracting authorities and private contractors. The simple design allows for example to quickly find information about who the biggest suppliers of local governments are, and the nature of the contracted goods and services. We believe the tool, which we make Open Source, is a valuable source of information for journalists, NGOs, analysts and citizens for getting information on public procurement data, from large scale trends to local municipal developments.
new_dataset
0.915658
1611.02120
Brett Meyer
Sean C. Smithson and Guang Yang and Warren J. Gross and Brett H. Meyer
Neural Networks Designing Neural Networks: Multi-Objective Hyper-Parameter Optimization
To appear in ICCAD'16. The authoritative version will appear in the ACM Digital Library
null
null
null
cs.NE cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Artificial neural networks have gone through a recent rise in popularity, achieving state-of-the-art results in various fields, including image classification, speech recognition, and automated control. Both the performance and computational complexity of such models are heavily dependant on the design of characteristic hyper-parameters (e.g., number of hidden layers, nodes per layer, or choice of activation functions), which have traditionally been optimized manually. With machine learning penetrating low-power mobile and embedded areas, the need to optimize not only for performance (accuracy), but also for implementation complexity, becomes paramount. In this work, we present a multi-objective design space exploration method that reduces the number of solution networks trained and evaluated through response surface modelling. Given spaces which can easily exceed 1020 solutions, manually designing a near-optimal architecture is unlikely as opportunities to reduce network complexity, while maintaining performance, may be overlooked. This problem is exacerbated by the fact that hyper-parameters which perform well on specific datasets may yield sub-par results on others, and must therefore be designed on a per-application basis. In our work, machine learning is leveraged by training an artificial neural network to predict the performance of future candidate networks. The method is evaluated on the MNIST and CIFAR-10 image datasets, optimizing for both recognition accuracy and computational complexity. Experimental results demonstrate that the proposed method can closely approximate the Pareto-optimal front, while only exploring a small fraction of the design space.
[ { "version": "v1", "created": "Mon, 7 Nov 2016 15:38:39 GMT" } ]
2016-11-08T00:00:00
[ [ "Smithson", "Sean C.", "" ], [ "Yang", "Guang", "" ], [ "Gross", "Warren J.", "" ], [ "Meyer", "Brett H.", "" ] ]
TITLE: Neural Networks Designing Neural Networks: Multi-Objective Hyper-Parameter Optimization ABSTRACT: Artificial neural networks have gone through a recent rise in popularity, achieving state-of-the-art results in various fields, including image classification, speech recognition, and automated control. Both the performance and computational complexity of such models are heavily dependant on the design of characteristic hyper-parameters (e.g., number of hidden layers, nodes per layer, or choice of activation functions), which have traditionally been optimized manually. With machine learning penetrating low-power mobile and embedded areas, the need to optimize not only for performance (accuracy), but also for implementation complexity, becomes paramount. In this work, we present a multi-objective design space exploration method that reduces the number of solution networks trained and evaluated through response surface modelling. Given spaces which can easily exceed 1020 solutions, manually designing a near-optimal architecture is unlikely as opportunities to reduce network complexity, while maintaining performance, may be overlooked. This problem is exacerbated by the fact that hyper-parameters which perform well on specific datasets may yield sub-par results on others, and must therefore be designed on a per-application basis. In our work, machine learning is leveraged by training an artificial neural network to predict the performance of future candidate networks. The method is evaluated on the MNIST and CIFAR-10 image datasets, optimizing for both recognition accuracy and computational complexity. Experimental results demonstrate that the proposed method can closely approximate the Pareto-optimal front, while only exploring a small fraction of the design space.
no_new_dataset
0.944331
1502.05890
Akshay Krishnamurthy
Akshay Krishnamurthy, Alekh Agarwal, Miroslav Dudik
Contextual Semibandits via Supervised Learning Oracles
null
null
null
null
cs.LG stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study an online decision making problem where on each round a learner chooses a list of items based on some side information, receives a scalar feedback value for each individual item, and a reward that is linearly related to this feedback. These problems, known as contextual semibandits, arise in crowdsourcing, recommendation, and many other domains. This paper reduces contextual semibandits to supervised learning, allowing us to leverage powerful supervised learning methods in this partial-feedback setting. Our first reduction applies when the mapping from feedback to reward is known and leads to a computationally efficient algorithm with near-optimal regret. We show that this algorithm outperforms state-of-the-art approaches on real-world learning-to-rank datasets, demonstrating the advantage of oracle-based algorithms. Our second reduction applies to the previously unstudied setting when the linear mapping from feedback to reward is unknown. Our regret guarantees are superior to prior techniques that ignore the feedback.
[ { "version": "v1", "created": "Fri, 20 Feb 2015 14:55:41 GMT" }, { "version": "v2", "created": "Thu, 5 Mar 2015 01:38:23 GMT" }, { "version": "v3", "created": "Tue, 14 Jun 2016 00:43:13 GMT" }, { "version": "v4", "created": "Fri, 4 Nov 2016 19:28:07 GMT" } ]
2016-11-07T00:00:00
[ [ "Krishnamurthy", "Akshay", "" ], [ "Agarwal", "Alekh", "" ], [ "Dudik", "Miroslav", "" ] ]
TITLE: Contextual Semibandits via Supervised Learning Oracles ABSTRACT: We study an online decision making problem where on each round a learner chooses a list of items based on some side information, receives a scalar feedback value for each individual item, and a reward that is linearly related to this feedback. These problems, known as contextual semibandits, arise in crowdsourcing, recommendation, and many other domains. This paper reduces contextual semibandits to supervised learning, allowing us to leverage powerful supervised learning methods in this partial-feedback setting. Our first reduction applies when the mapping from feedback to reward is known and leads to a computationally efficient algorithm with near-optimal regret. We show that this algorithm outperforms state-of-the-art approaches on real-world learning-to-rank datasets, demonstrating the advantage of oracle-based algorithms. Our second reduction applies to the previously unstudied setting when the linear mapping from feedback to reward is unknown. Our regret guarantees are superior to prior techniques that ignore the feedback.
no_new_dataset
0.948202
1611.00938
Johann Paratte
Johan Paratte and Lionel Martin
Fast Eigenspace Approximation using Random Signals
null
null
null
null
cs.DS cs.LG stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We focus in this work on the estimation of the first $k$ eigenvectors of any graph Laplacian using filtering of Gaussian random signals. We prove that we only need $k$ such signals to be able to exactly recover as many of the smallest eigenvectors, regardless of the number of nodes in the graph. In addition, we address key issues in implementing the theoretical concepts in practice using accurate approximated methods. We also propose fast algorithms both for eigenspace approximation and for the determination of the $k$th smallest eigenvalue $\lambda_k$. The latter proves to be extremely efficient under the assumption of locally uniform distribution of the eigenvalue over the spectrum. Finally, we present experiments which show the validity of our method in practice and compare it to state-of-the-art methods for clustering and visualization both on synthetic small-scale datasets and larger real-world problems of millions of nodes. We show that our method allows a better scaling with the number of nodes than all previous methods while achieving an almost perfect reconstruction of the eigenspace formed by the first $k$ eigenvectors.
[ { "version": "v1", "created": "Thu, 3 Nov 2016 10:08:22 GMT" }, { "version": "v2", "created": "Fri, 4 Nov 2016 09:25:41 GMT" } ]
2016-11-07T00:00:00
[ [ "Paratte", "Johan", "" ], [ "Martin", "Lionel", "" ] ]
TITLE: Fast Eigenspace Approximation using Random Signals ABSTRACT: We focus in this work on the estimation of the first $k$ eigenvectors of any graph Laplacian using filtering of Gaussian random signals. We prove that we only need $k$ such signals to be able to exactly recover as many of the smallest eigenvectors, regardless of the number of nodes in the graph. In addition, we address key issues in implementing the theoretical concepts in practice using accurate approximated methods. We also propose fast algorithms both for eigenspace approximation and for the determination of the $k$th smallest eigenvalue $\lambda_k$. The latter proves to be extremely efficient under the assumption of locally uniform distribution of the eigenvalue over the spectrum. Finally, we present experiments which show the validity of our method in practice and compare it to state-of-the-art methods for clustering and visualization both on synthetic small-scale datasets and larger real-world problems of millions of nodes. We show that our method allows a better scaling with the number of nodes than all previous methods while achieving an almost perfect reconstruction of the eigenspace formed by the first $k$ eigenvectors.
no_new_dataset
0.945197
1611.01195
Shusil Dangi
Shusil Dangi, Nathan Cahill, Cristian A. Linte
Integrating Atlas and Graph Cut Methods for LV Segmentation from Cardiac Cine MRI
Statistical Atlases and Computational Modelling of Heart workshop 2016
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Magnetic Resonance Imaging (MRI) has evolved as a clinical standard-of-care imaging modality for cardiac morphology, function assessment, and guidance of cardiac interventions. All these applications rely on accurate extraction of the myocardial tissue and blood pool from the imaging data. Here we propose a framework for left ventricle (LV) segmentation from cardiac cine-MRI. First, we segment the LV blood pool using iterative graph cuts, and subsequently use this information to segment the myocardium. We formulate the segmentation procedure as an energy minimization problem in a graph subject to the shape prior obtained by label propagation from an average atlas using affine registration. The proposed framework has been validated on 30 patient cardiac cine-MRI datasets available through the STACOM LV segmentation challenge and yielded fast, robust, and accurate segmentation results.
[ { "version": "v1", "created": "Thu, 3 Nov 2016 21:12:55 GMT" } ]
2016-11-07T00:00:00
[ [ "Dangi", "Shusil", "" ], [ "Cahill", "Nathan", "" ], [ "Linte", "Cristian A.", "" ] ]
TITLE: Integrating Atlas and Graph Cut Methods for LV Segmentation from Cardiac Cine MRI ABSTRACT: Magnetic Resonance Imaging (MRI) has evolved as a clinical standard-of-care imaging modality for cardiac morphology, function assessment, and guidance of cardiac interventions. All these applications rely on accurate extraction of the myocardial tissue and blood pool from the imaging data. Here we propose a framework for left ventricle (LV) segmentation from cardiac cine-MRI. First, we segment the LV blood pool using iterative graph cuts, and subsequently use this information to segment the myocardium. We formulate the segmentation procedure as an energy minimization problem in a graph subject to the shape prior obtained by label propagation from an average atlas using affine registration. The proposed framework has been validated on 30 patient cardiac cine-MRI datasets available through the STACOM LV segmentation challenge and yielded fast, robust, and accurate segmentation results.
no_new_dataset
0.952353
1611.01235
Tiffany Hwu
Tiffany Hwu, Jacob Isbell, Nicolas Oros, and Jeffrey Krichmar
A Self-Driving Robot Using Deep Convolutional Neural Networks on Neuromorphic Hardware
6 pages, 8 figures
null
null
null
cs.NE cs.RO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Neuromorphic computing is a promising solution for reducing the size, weight and power of mobile embedded systems. In this paper, we introduce a realization of such a system by creating the first closed-loop battery-powered communication system between an IBM TrueNorth NS1e and an autonomous Android-Based Robotics platform. Using this system, we constructed a dataset of path following behavior by manually driving the Android-Based robot along steep mountain trails and recording video frames from the camera mounted on the robot along with the corresponding motor commands. We used this dataset to train a deep convolutional neural network implemented on the TrueNorth NS1e. The NS1e, which was mounted on the robot and powered by the robot's battery, resulted in a self-driving robot that could successfully traverse a steep mountain path in real time. To our knowledge, this represents the first time the TrueNorth NS1e neuromorphic chip has been embedded on a mobile platform under closed-loop control.
[ { "version": "v1", "created": "Fri, 4 Nov 2016 01:10:07 GMT" } ]
2016-11-07T00:00:00
[ [ "Hwu", "Tiffany", "" ], [ "Isbell", "Jacob", "" ], [ "Oros", "Nicolas", "" ], [ "Krichmar", "Jeffrey", "" ] ]
TITLE: A Self-Driving Robot Using Deep Convolutional Neural Networks on Neuromorphic Hardware ABSTRACT: Neuromorphic computing is a promising solution for reducing the size, weight and power of mobile embedded systems. In this paper, we introduce a realization of such a system by creating the first closed-loop battery-powered communication system between an IBM TrueNorth NS1e and an autonomous Android-Based Robotics platform. Using this system, we constructed a dataset of path following behavior by manually driving the Android-Based robot along steep mountain trails and recording video frames from the camera mounted on the robot along with the corresponding motor commands. We used this dataset to train a deep convolutional neural network implemented on the TrueNorth NS1e. The NS1e, which was mounted on the robot and powered by the robot's battery, resulted in a self-driving robot that could successfully traverse a steep mountain path in real time. To our knowledge, this represents the first time the TrueNorth NS1e neuromorphic chip has been embedded on a mobile platform under closed-loop control.
new_dataset
0.973418
1611.01242
Mohit Iyyer
Mohit Iyyer, Wen-tau Yih, Ming-Wei Chang
Answering Complicated Question Intents Expressed in Decomposed Question Sequences
null
null
null
null
cs.CL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recent work in semantic parsing for question answering has focused on long and complicated questions, many of which would seem unnatural if asked in a normal conversation between two humans. In an effort to explore a conversational QA setting, we present a more realistic task: answering sequences of simple but inter-related questions. We collect a dataset of 6,066 question sequences that inquire about semi-structured tables from Wikipedia, with 17,553 question-answer pairs in total. Existing QA systems face two major problems when evaluated on our dataset: (1) handling questions that contain coreferences to previous questions or answers, and (2) matching words or phrases in a question to corresponding entries in the associated table. We conclude by proposing strategies to handle both of these issues.
[ { "version": "v1", "created": "Fri, 4 Nov 2016 01:54:03 GMT" } ]
2016-11-07T00:00:00
[ [ "Iyyer", "Mohit", "" ], [ "Yih", "Wen-tau", "" ], [ "Chang", "Ming-Wei", "" ] ]
TITLE: Answering Complicated Question Intents Expressed in Decomposed Question Sequences ABSTRACT: Recent work in semantic parsing for question answering has focused on long and complicated questions, many of which would seem unnatural if asked in a normal conversation between two humans. In an effort to explore a conversational QA setting, we present a more realistic task: answering sequences of simple but inter-related questions. We collect a dataset of 6,066 question sequences that inquire about semi-structured tables from Wikipedia, with 17,553 question-answer pairs in total. Existing QA systems face two major problems when evaluated on our dataset: (1) handling questions that contain coreferences to previous questions or answers, and (2) matching words or phrases in a question to corresponding entries in the associated table. We conclude by proposing strategies to handle both of these issues.
new_dataset
0.957715
1611.01276
Qi Meng
Qi Meng, Guolin Ke, Taifeng Wang, Wei Chen, Qiwei Ye, Zhi-Ming Ma and Tie-Yan Liu
A Communication-Efficient Parallel Algorithm for Decision Tree
null
null
null
null
cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Decision tree (and its extensions such as Gradient Boosting Decision Trees and Random Forest) is a widely used machine learning algorithm, due to its practical effectiveness and model interpretability. With the emergence of big data, there is an increasing need to parallelize the training process of decision tree. However, most existing attempts along this line suffer from high communication costs. In this paper, we propose a new algorithm, called \emph{Parallel Voting Decision Tree (PV-Tree)}, to tackle this challenge. After partitioning the training data onto a number of (e.g., $M$) machines, this algorithm performs both local voting and global voting in each iteration. For local voting, the top-$k$ attributes are selected from each machine according to its local data. Then, globally top-$2k$ attributes are determined by a majority voting among these local candidates. Finally, the full-grained histograms of the globally top-$2k$ attributes are collected from local machines in order to identify the best (most informative) attribute and its split point. PV-Tree can achieve a very low communication cost (independent of the total number of attributes) and thus can scale out very well. Furthermore, theoretical analysis shows that this algorithm can learn a near optimal decision tree, since it can find the best attribute with a large probability. Our experiments on real-world datasets show that PV-Tree significantly outperforms the existing parallel decision tree algorithms in the trade-off between accuracy and efficiency.
[ { "version": "v1", "created": "Fri, 4 Nov 2016 07:09:03 GMT" } ]
2016-11-07T00:00:00
[ [ "Meng", "Qi", "" ], [ "Ke", "Guolin", "" ], [ "Wang", "Taifeng", "" ], [ "Chen", "Wei", "" ], [ "Ye", "Qiwei", "" ], [ "Ma", "Zhi-Ming", "" ], [ "Liu", "Tie-Yan", "" ] ]
TITLE: A Communication-Efficient Parallel Algorithm for Decision Tree ABSTRACT: Decision tree (and its extensions such as Gradient Boosting Decision Trees and Random Forest) is a widely used machine learning algorithm, due to its practical effectiveness and model interpretability. With the emergence of big data, there is an increasing need to parallelize the training process of decision tree. However, most existing attempts along this line suffer from high communication costs. In this paper, we propose a new algorithm, called \emph{Parallel Voting Decision Tree (PV-Tree)}, to tackle this challenge. After partitioning the training data onto a number of (e.g., $M$) machines, this algorithm performs both local voting and global voting in each iteration. For local voting, the top-$k$ attributes are selected from each machine according to its local data. Then, globally top-$2k$ attributes are determined by a majority voting among these local candidates. Finally, the full-grained histograms of the globally top-$2k$ attributes are collected from local machines in order to identify the best (most informative) attribute and its split point. PV-Tree can achieve a very low communication cost (independent of the total number of attributes) and thus can scale out very well. Furthermore, theoretical analysis shows that this algorithm can learn a near optimal decision tree, since it can find the best attribute with a large probability. Our experiments on real-world datasets show that PV-Tree significantly outperforms the existing parallel decision tree algorithms in the trade-off between accuracy and efficiency.
no_new_dataset
0.948537
1611.01503
Akosua Busia
Akosua Busia, Jasmine Collins, Navdeep Jaitly
Protein Secondary Structure Prediction Using Deep Multi-scale Convolutional Neural Networks and Next-Step Conditioning
10 pages, 2 figures, submitted to RECOMB 2017
null
null
null
cs.LG q-bio.BM
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recently developed deep learning techniques have significantly improved the accuracy of various speech and image recognition systems. In this paper we adapt some of these techniques for protein secondary structure prediction. We first train a series of deep neural networks to predict eight-class secondary structure labels given a protein's amino acid sequence information and find that using recent methods for regularization, such as dropout and weight-norm constraining, leads to measurable gains in accuracy. We then adapt recent convolutional neural network architectures--Inception, ReSNet, and DenseNet with Batch Normalization--to the problem of protein structure prediction. These convolutional architectures make heavy use of multi-scale filter layers that simultaneously compute features on several scales, and use residual connections to prevent underfitting. Using a carefully modified version of these architectures, we achieve state-of-the-art performance of 70.0% per amino acid accuracy on the public CB513 benchmark dataset. Finally, we explore additions from sequence-to-sequence learning, altering the model to make its predictions conditioned on both the protein's amino acid sequence and its past secondary structure labels. We introduce a new method of ensembling such a conditional model with our convolutional model, an approach which reaches 70.6% Q8 accuracy on CB513. We argue that these results can be further refined for larger boosts in prediction accuracy through more sophisticated attempts to control overfitting of conditional models. We aim to release the code for these experiments as part of the TensorFlow repository.
[ { "version": "v1", "created": "Fri, 4 Nov 2016 19:32:15 GMT" } ]
2016-11-07T00:00:00
[ [ "Busia", "Akosua", "" ], [ "Collins", "Jasmine", "" ], [ "Jaitly", "Navdeep", "" ] ]
TITLE: Protein Secondary Structure Prediction Using Deep Multi-scale Convolutional Neural Networks and Next-Step Conditioning ABSTRACT: Recently developed deep learning techniques have significantly improved the accuracy of various speech and image recognition systems. In this paper we adapt some of these techniques for protein secondary structure prediction. We first train a series of deep neural networks to predict eight-class secondary structure labels given a protein's amino acid sequence information and find that using recent methods for regularization, such as dropout and weight-norm constraining, leads to measurable gains in accuracy. We then adapt recent convolutional neural network architectures--Inception, ReSNet, and DenseNet with Batch Normalization--to the problem of protein structure prediction. These convolutional architectures make heavy use of multi-scale filter layers that simultaneously compute features on several scales, and use residual connections to prevent underfitting. Using a carefully modified version of these architectures, we achieve state-of-the-art performance of 70.0% per amino acid accuracy on the public CB513 benchmark dataset. Finally, we explore additions from sequence-to-sequence learning, altering the model to make its predictions conditioned on both the protein's amino acid sequence and its past secondary structure labels. We introduce a new method of ensembling such a conditional model with our convolutional model, an approach which reaches 70.6% Q8 accuracy on CB513. We argue that these results can be further refined for larger boosts in prediction accuracy through more sophisticated attempts to control overfitting of conditional models. We aim to release the code for these experiments as part of the TensorFlow repository.
no_new_dataset
0.951278
1501.02990
Yi Li
Yi Wang, Yi Li, Momiao Xiong, Li Jin
Random Bits Regression: a Strong General Predictor for Big Data
20 pages,1 figure, 2 tables, research article
Big Data Analytics 2016 1:12
10.1186/s41044-016-0010-4
null
stat.ML cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
To improve accuracy and speed of regressions and classifications, we present a data-based prediction method, Random Bits Regression (RBR). This method first generates a large number of random binary intermediate/derived features based on the original input matrix, and then performs regularized linear/logistic regression on those intermediate/derived features to predict the outcome. Benchmark analyses on a simulated dataset, UCI machine learning repository datasets and a GWAS dataset showed that RBR outperforms other popular methods in accuracy and robustness. RBR (available on https://sourceforge.net/projects/rbr/) is very fast and requires reasonable memories, therefore, provides a strong, robust and fast predictor in the big data era.
[ { "version": "v1", "created": "Tue, 13 Jan 2015 13:14:42 GMT" } ]
2016-11-04T00:00:00
[ [ "Wang", "Yi", "" ], [ "Li", "Yi", "" ], [ "Xiong", "Momiao", "" ], [ "Jin", "Li", "" ] ]
TITLE: Random Bits Regression: a Strong General Predictor for Big Data ABSTRACT: To improve accuracy and speed of regressions and classifications, we present a data-based prediction method, Random Bits Regression (RBR). This method first generates a large number of random binary intermediate/derived features based on the original input matrix, and then performs regularized linear/logistic regression on those intermediate/derived features to predict the outcome. Benchmark analyses on a simulated dataset, UCI machine learning repository datasets and a GWAS dataset showed that RBR outperforms other popular methods in accuracy and robustness. RBR (available on https://sourceforge.net/projects/rbr/) is very fast and requires reasonable memories, therefore, provides a strong, robust and fast predictor in the big data era.
no_new_dataset
0.947088
1609.04112
C.-C. Jay Kuo
C.-C. Jay Kuo
Understanding Convolutional Neural Networks with A Mathematical Model
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This work attempts to address two fundamental questions about the structure of the convolutional neural networks (CNN): 1) why a non-linear activation function is essential at the filter output of every convolutional layer? 2) what is the advantage of the two-layer cascade system over the one-layer system? A mathematical model called the "REctified-COrrelations on a Sphere" (RECOS) is proposed to answer these two questions. After the CNN training process, the converged filter weights define a set of anchor vectors in the RECOS model. Anchor vectors represent the frequently occurring patterns (or the spectral components). The necessity of rectification is explained using the RECOS model. Then, the behavior of a two-layer RECOS system is analyzed and compared with its one-layer counterpart. The LeNet-5 and the MNIST dataset are used to illustrate discussion points. Finally, the RECOS model is generalized to a multi-layer system with the AlexNet as an example. Keywords: Convolutional Neural Network (CNN), Nonlinear Activation, RECOS Model, Rectified Linear Unit (ReLU), MNIST Dataset.
[ { "version": "v1", "created": "Wed, 14 Sep 2016 02:17:09 GMT" }, { "version": "v2", "created": "Wed, 2 Nov 2016 21:55:26 GMT" } ]
2016-11-04T00:00:00
[ [ "Kuo", "C. -C. Jay", "" ] ]
TITLE: Understanding Convolutional Neural Networks with A Mathematical Model ABSTRACT: This work attempts to address two fundamental questions about the structure of the convolutional neural networks (CNN): 1) why a non-linear activation function is essential at the filter output of every convolutional layer? 2) what is the advantage of the two-layer cascade system over the one-layer system? A mathematical model called the "REctified-COrrelations on a Sphere" (RECOS) is proposed to answer these two questions. After the CNN training process, the converged filter weights define a set of anchor vectors in the RECOS model. Anchor vectors represent the frequently occurring patterns (or the spectral components). The necessity of rectification is explained using the RECOS model. Then, the behavior of a two-layer RECOS system is analyzed and compared with its one-layer counterpart. The LeNet-5 and the MNIST dataset are used to illustrate discussion points. Finally, the RECOS model is generalized to a multi-layer system with the AlexNet as an example. Keywords: Convolutional Neural Network (CNN), Nonlinear Activation, RECOS Model, Rectified Linear Unit (ReLU), MNIST Dataset.
no_new_dataset
0.951818
1610.01969
Hyrum Anderson
Hyrum S. Anderson, Jonathan Woodbridge and Bobby Filar
DeepDGA: Adversarially-Tuned Domain Generation and Detection
null
null
null
null
cs.CR cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Many malware families utilize domain generation algorithms (DGAs) to establish command and control (C&C) connections. While there are many methods to pseudorandomly generate domains, we focus in this paper on detecting (and generating) domains on a per-domain basis which provides a simple and flexible means to detect known DGA families. Recent machine learning approaches to DGA detection have been successful on fairly simplistic DGAs, many of which produce names of fixed length. However, models trained on limited datasets are somewhat blind to new DGA variants. In this paper, we leverage the concept of generative adversarial networks to construct a deep learning based DGA that is designed to intentionally bypass a deep learning based detector. In a series of adversarial rounds, the generator learns to generate domain names that are increasingly more difficult to detect. In turn, a detector model updates its parameters to compensate for the adversarially generated domains. We test the hypothesis of whether adversarially generated domains may be used to augment training sets in order to harden other machine learning models against yet-to-be-observed DGAs. We detail solutions to several challenges in training this character-based generative adversarial network (GAN). In particular, our deep learning architecture begins as a domain name auto-encoder (encoder + decoder) trained on domains in the Alexa one million. Then the encoder and decoder are reassembled competitively in a generative adversarial network (detector + generator), with novel neural architectures and training strategies to improve convergence.
[ { "version": "v1", "created": "Thu, 6 Oct 2016 17:50:27 GMT" } ]
2016-11-04T00:00:00
[ [ "Anderson", "Hyrum S.", "" ], [ "Woodbridge", "Jonathan", "" ], [ "Filar", "Bobby", "" ] ]
TITLE: DeepDGA: Adversarially-Tuned Domain Generation and Detection ABSTRACT: Many malware families utilize domain generation algorithms (DGAs) to establish command and control (C&C) connections. While there are many methods to pseudorandomly generate domains, we focus in this paper on detecting (and generating) domains on a per-domain basis which provides a simple and flexible means to detect known DGA families. Recent machine learning approaches to DGA detection have been successful on fairly simplistic DGAs, many of which produce names of fixed length. However, models trained on limited datasets are somewhat blind to new DGA variants. In this paper, we leverage the concept of generative adversarial networks to construct a deep learning based DGA that is designed to intentionally bypass a deep learning based detector. In a series of adversarial rounds, the generator learns to generate domain names that are increasingly more difficult to detect. In turn, a detector model updates its parameters to compensate for the adversarially generated domains. We test the hypothesis of whether adversarially generated domains may be used to augment training sets in order to harden other machine learning models against yet-to-be-observed DGAs. We detail solutions to several challenges in training this character-based generative adversarial network (GAN). In particular, our deep learning architecture begins as a domain name auto-encoder (encoder + decoder) trained on domains in the Alexa one million. Then the encoder and decoder are reassembled competitively in a generative adversarial network (detector + generator), with novel neural architectures and training strategies to improve convergence.
no_new_dataset
0.94699
1611.00791
Hyrum Anderson
Jonathan Woodbridge, Hyrum S. Anderson, Anjum Ahuja and Daniel Grant
Predicting Domain Generation Algorithms with Long Short-Term Memory Networks
null
null
null
null
cs.CR cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Various families of malware use domain generation algorithms (DGAs) to generate a large number of pseudo-random domain names to connect to a command and control (C&C) server. In order to block DGA C&C traffic, security organizations must first discover the algorithm by reverse engineering malware samples, then generating a list of domains for a given seed. The domains are then either preregistered or published in a DNS blacklist. This process is not only tedious, but can be readily circumvented by malware authors using a large number of seeds in algorithms with multivariate recurrence properties (e.g., banjori) or by using a dynamic list of seeds (e.g., bedep). Another technique to stop malware from using DGAs is to intercept DNS queries on a network and predict whether domains are DGA generated. Such a technique will alert network administrators to the presence of malware on their networks. In addition, if the predictor can also accurately predict the family of DGAs, then network administrators can also be alerted to the type of malware that is on their networks. This paper presents a DGA classifier that leverages long short-term memory (LSTM) networks to predict DGAs and their respective families without the need for a priori feature extraction. Results are significantly better than state-of-the-art techniques, providing 0.9993 area under the receiver operating characteristic curve for binary classification and a micro-averaged F1 score of 0.9906. In other terms, the LSTM technique can provide a 90% detection rate with a 1:10000 false positive (FP) rate---a twenty times FP improvement over comparable methods. Experiments in this paper are run on open datasets and code snippets are provided to reproduce the results.
[ { "version": "v1", "created": "Wed, 2 Nov 2016 20:34:56 GMT" } ]
2016-11-04T00:00:00
[ [ "Woodbridge", "Jonathan", "" ], [ "Anderson", "Hyrum S.", "" ], [ "Ahuja", "Anjum", "" ], [ "Grant", "Daniel", "" ] ]
TITLE: Predicting Domain Generation Algorithms with Long Short-Term Memory Networks ABSTRACT: Various families of malware use domain generation algorithms (DGAs) to generate a large number of pseudo-random domain names to connect to a command and control (C&C) server. In order to block DGA C&C traffic, security organizations must first discover the algorithm by reverse engineering malware samples, then generating a list of domains for a given seed. The domains are then either preregistered or published in a DNS blacklist. This process is not only tedious, but can be readily circumvented by malware authors using a large number of seeds in algorithms with multivariate recurrence properties (e.g., banjori) or by using a dynamic list of seeds (e.g., bedep). Another technique to stop malware from using DGAs is to intercept DNS queries on a network and predict whether domains are DGA generated. Such a technique will alert network administrators to the presence of malware on their networks. In addition, if the predictor can also accurately predict the family of DGAs, then network administrators can also be alerted to the type of malware that is on their networks. This paper presents a DGA classifier that leverages long short-term memory (LSTM) networks to predict DGAs and their respective families without the need for a priori feature extraction. Results are significantly better than state-of-the-art techniques, providing 0.9993 area under the receiver operating characteristic curve for binary classification and a micro-averaged F1 score of 0.9906. In other terms, the LSTM technique can provide a 90% detection rate with a 1:10000 false positive (FP) rate---a twenty times FP improvement over comparable methods. Experiments in this paper are run on open datasets and code snippets are provided to reproduce the results.
no_new_dataset
0.949248
1611.00800
Andy Jinhua Ma
Frodo Kin Sun Chan, Andy J Ma, Pong C Yuen, Terry Cheuk-Fung Yip, Yee-Kit Tse, Vincent Wai-Sun Wong and Grace Lai-Hung Wong
Temporal Matrix Completion with Locally Linear Latent Factors for Medical Applications
null
null
null
null
cs.LG cs.CV stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Regular medical records are useful for medical practitioners to analyze and monitor patient health status especially for those with chronic disease, but such records are usually incomplete due to unpunctuality and absence of patients. In order to resolve the missing data problem over time, tensor-based model is suggested for missing data imputation in recent papers because this approach makes use of low rank tensor assumption for highly correlated data. However, when the time intervals between records are long, the data correlation is not high along temporal direction and such assumption is not valid. To address this problem, we propose to decompose a matrix with missing data into its latent factors. Then, the locally linear constraint is imposed on these factors for matrix completion in this paper. By using a publicly available dataset and two medical datasets collected from hospital, experimental results show that the proposed algorithm achieves the best performance by comparing with the existing methods.
[ { "version": "v1", "created": "Mon, 31 Oct 2016 12:02:53 GMT" } ]
2016-11-04T00:00:00
[ [ "Chan", "Frodo Kin Sun", "" ], [ "Ma", "Andy J", "" ], [ "Yuen", "Pong C", "" ], [ "Yip", "Terry Cheuk-Fung", "" ], [ "Tse", "Yee-Kit", "" ], [ "Wong", "Vincent Wai-Sun", "" ], [ "Wong", "Grace Lai-Hung", "" ] ]
TITLE: Temporal Matrix Completion with Locally Linear Latent Factors for Medical Applications ABSTRACT: Regular medical records are useful for medical practitioners to analyze and monitor patient health status especially for those with chronic disease, but such records are usually incomplete due to unpunctuality and absence of patients. In order to resolve the missing data problem over time, tensor-based model is suggested for missing data imputation in recent papers because this approach makes use of low rank tensor assumption for highly correlated data. However, when the time intervals between records are long, the data correlation is not high along temporal direction and such assumption is not valid. To address this problem, we propose to decompose a matrix with missing data into its latent factors. Then, the locally linear constraint is imposed on these factors for matrix completion in this paper. By using a publicly available dataset and two medical datasets collected from hospital, experimental results show that the proposed algorithm achieves the best performance by comparing with the existing methods.
no_new_dataset
0.944177
1611.00822
Evgeniya Ustinova
Evgeniya Ustinova, Victor Lempitsky
Learning Deep Embeddings with Histogram Loss
NIPS 2016
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We suggest a loss for learning deep embeddings. The new loss does not introduce parameters that need to be tuned and results in very good embeddings across a range of datasets and problems. The loss is computed by estimating two distribution of similarities for positive (matching) and negative (non-matching) sample pairs, and then computing the probability of a positive pair to have a lower similarity score than a negative pair based on the estimated similarity distributions. We show that such operations can be performed in a simple and piecewise-differentiable manner using 1D histograms with soft assignment operations. This makes the proposed loss suitable for learning deep embeddings using stochastic optimization. In the experiments, the new loss performs favourably compared to recently proposed alternatives.
[ { "version": "v1", "created": "Wed, 2 Nov 2016 21:48:32 GMT" } ]
2016-11-04T00:00:00
[ [ "Ustinova", "Evgeniya", "" ], [ "Lempitsky", "Victor", "" ] ]
TITLE: Learning Deep Embeddings with Histogram Loss ABSTRACT: We suggest a loss for learning deep embeddings. The new loss does not introduce parameters that need to be tuned and results in very good embeddings across a range of datasets and problems. The loss is computed by estimating two distribution of similarities for positive (matching) and negative (non-matching) sample pairs, and then computing the probability of a positive pair to have a lower similarity score than a negative pair based on the estimated similarity distributions. We show that such operations can be performed in a simple and piecewise-differentiable manner using 1D histograms with soft assignment operations. This makes the proposed loss suitable for learning deep embeddings using stochastic optimization. In the experiments, the new loss performs favourably compared to recently proposed alternatives.
no_new_dataset
0.947478
1611.00873
Qiang Lyu
Qiang Lyu, Yixin Chen, Zhaorong Li, Zhicheng Cui, Ling Chen, Xing Zhang, Haihua Shen
Extracting Actionability from Machine Learning Models by Sub-optimal Deterministic Planning
16 pages, 4 figures
null
null
null
cs.AI cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A main focus of machine learning research has been improving the generalization accuracy and efficiency of prediction models. Many models such as SVM, random forest, and deep neural nets have been proposed and achieved great success. However, what emerges as missing in many applications is actionability, i.e., the ability to turn prediction results into actions. For example, in applications such as customer relationship management, clinical prediction, and advertisement, the users need not only accurate prediction, but also actionable instructions which can transfer an input to a desirable goal (e.g., higher profit repays, lower morbidity rates, higher ads hit rates). Existing effort in deriving such actionable knowledge is few and limited to simple action models which restricted to only change one attribute for each action. The dilemma is that in many real applications those action models are often more complex and harder to extract an optimal solution. In this paper, we propose a novel approach that achieves actionability by combining learning with planning, two core areas of AI. In particular, we propose a framework to extract actionable knowledge from random forest, one of the most widely used and best off-the-shelf classifiers. We formulate the actionability problem to a sub-optimal action planning (SOAP) problem, which is to find a plan to alter certain features of a given input so that the random forest would yield a desirable output, while minimizing the total costs of actions. Technically, the SOAP problem is formulated in the SAS+ planning formalism, and solved using a Max-SAT based approach. Our experimental results demonstrate the effectiveness and efficiency of the proposed approach on a personal credit dataset and other benchmarks. Our work represents a new application of automated planning on an emerging and challenging machine learning paradigm.
[ { "version": "v1", "created": "Thu, 3 Nov 2016 03:53:41 GMT" } ]
2016-11-04T00:00:00
[ [ "Lyu", "Qiang", "" ], [ "Chen", "Yixin", "" ], [ "Li", "Zhaorong", "" ], [ "Cui", "Zhicheng", "" ], [ "Chen", "Ling", "" ], [ "Zhang", "Xing", "" ], [ "Shen", "Haihua", "" ] ]
TITLE: Extracting Actionability from Machine Learning Models by Sub-optimal Deterministic Planning ABSTRACT: A main focus of machine learning research has been improving the generalization accuracy and efficiency of prediction models. Many models such as SVM, random forest, and deep neural nets have been proposed and achieved great success. However, what emerges as missing in many applications is actionability, i.e., the ability to turn prediction results into actions. For example, in applications such as customer relationship management, clinical prediction, and advertisement, the users need not only accurate prediction, but also actionable instructions which can transfer an input to a desirable goal (e.g., higher profit repays, lower morbidity rates, higher ads hit rates). Existing effort in deriving such actionable knowledge is few and limited to simple action models which restricted to only change one attribute for each action. The dilemma is that in many real applications those action models are often more complex and harder to extract an optimal solution. In this paper, we propose a novel approach that achieves actionability by combining learning with planning, two core areas of AI. In particular, we propose a framework to extract actionable knowledge from random forest, one of the most widely used and best off-the-shelf classifiers. We formulate the actionability problem to a sub-optimal action planning (SOAP) problem, which is to find a plan to alter certain features of a given input so that the random forest would yield a desirable output, while minimizing the total costs of actions. Technically, the SOAP problem is formulated in the SAS+ planning formalism, and solved using a Max-SAT based approach. Our experimental results demonstrate the effectiveness and efficiency of the proposed approach on a personal credit dataset and other benchmarks. Our work represents a new application of automated planning on an emerging and challenging machine learning paradigm.
no_new_dataset
0.9455