April 2, 2020

3263 words 16 mins read

Paper Group ANR 306

Paper Group ANR 306

Analysis Of Multi Field Of View Cnn And Attention Cnn On H&E Stained Whole-slide Images On Hepatocellular Carcinoma. A Preliminary Approach for Learning Relational Policies for the Management of Critically Ill Children. Optimal Randomized First-Order Methods for Least-Squares Problems. ActiLabel: A Combinatorial Transfer Learning Framework for Acti …

Analysis Of Multi Field Of View Cnn And Attention Cnn On H&E Stained Whole-slide Images On Hepatocellular Carcinoma

Title Analysis Of Multi Field Of View Cnn And Attention Cnn On H&E Stained Whole-slide Images On Hepatocellular Carcinoma
Authors Mehmet Burak Sayıcı, Rikiya Yamashita, Jeanne Shen
Abstract Hepatocellular carcinoma (HCC) is a leading cause of cancer-related death worldwide. Whole-slide imaging which is a method of scanning glass slides have been employed for diagnosis of HCC. Using high resolution Whole-slide images is infeasible for Convolutional Neural Network applications. Hence tiling the Whole-slide images is a common methodology for assigning Convolutional Neural Networks for classification and segmentation. Determination of the tile size affects the performance of the algorithms since small field of view can not capture the information on a larger scale and large field of view can not capture the information on a cellular scale. In this work, the effect of tile size on performance for classification problem is analysed. In addition, Multi Field of View CNN is assigned for taking advantage of the information provided by different tile sizes and Attention CNN is assigned for giving the capability of voting most contributing tile size. It is found that employing more than one tile size significantly increases the performance of the classification by 3.97% and both algorithms are found successful over the algorithm which uses only one tile size.
Tasks
Published 2020-02-12
URL https://arxiv.org/abs/2002.04836v2
PDF https://arxiv.org/pdf/2002.04836v2.pdf
PWC https://paperswithcode.com/paper/analysis-of-multi-field-of-view-cnn-and
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A Preliminary Approach for Learning Relational Policies for the Management of Critically Ill Children

Title A Preliminary Approach for Learning Relational Policies for the Management of Critically Ill Children
Authors Michael A. Skinner, Lakshmi Raman, Neel Shah, Abdelaziz Farhat, Sriraam Natarajan
Abstract The increased use of electronic health records has made possible the automated extraction of medical policies from patient records to aid in the development of clinical decision support systems. We adapted a boosted Statistical Relational Learning (SRL) framework to learn probabilistic rules from clinical hospital records for the management of physiologic parameters of children with severe cardiac or respiratory failure who were managed with extracorporeal membrane oxygenation. In this preliminary study, the results were promising. In particular, the algorithm returned logic rules for medical actions that are consistent with medical reasoning.
Tasks Relational Reasoning
Published 2020-01-13
URL https://arxiv.org/abs/2001.04432v1
PDF https://arxiv.org/pdf/2001.04432v1.pdf
PWC https://paperswithcode.com/paper/a-preliminary-approach-for-learning
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Optimal Randomized First-Order Methods for Least-Squares Problems

Title Optimal Randomized First-Order Methods for Least-Squares Problems
Authors Jonathan Lacotte, Mert Pilanci
Abstract We provide an exact analysis of a class of randomized algorithms for solving overdetermined least-squares problems. We consider first-order methods, where the gradients are pre-conditioned by an approximation of the Hessian, based on a subspace embedding of the data matrix. This class of algorithms encompasses several randomized methods among the fastest solvers for least-squares problems. We focus on two classical embeddings, namely, Gaussian projections and subsampled randomized Hadamard transforms (SRHT). Our key technical innovation is the derivation of the limiting spectral density of SRHT embeddings. Leveraging this novel result, we derive the family of normalized orthogonal polynomials of the SRHT density and we find the optimal pre-conditioned first-order method along with its rate of convergence. Our analysis of Gaussian embeddings proceeds similarly, and leverages classical random matrix theory results. In particular, we show that for a given sketch size, SRHT embeddings exhibits a faster rate of convergence than Gaussian embeddings. Then, we propose a new algorithm by optimizing the computational complexity over the choice of the sketching dimension. To our knowledge, our resulting algorithm yields the best known complexity for solving least-squares problems with no condition number dependence.
Tasks
Published 2020-02-21
URL https://arxiv.org/abs/2002.09488v2
PDF https://arxiv.org/pdf/2002.09488v2.pdf
PWC https://paperswithcode.com/paper/optimal-randomized-first-order-methods-for
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ActiLabel: A Combinatorial Transfer Learning Framework for Activity Recognition

Title ActiLabel: A Combinatorial Transfer Learning Framework for Activity Recognition
Authors Parastoo Alinia, Iman Mirzadeh, Hassan Ghasemzadeh
Abstract Sensor-based human activity recognition has become a critical component of many emerging applications ranging from behavioral medicine to gaming. However, an unprecedented increase in the diversity of sensor devices in the Internet-of-Things era has limited the adoption of activity recognition models for use across different domains. We propose ActiLabel a combinatorial framework that learns structural similarities among the events in an arbitrary domain and those of a different domain. The structural similarities are captured through a graph model, referred to as the it dependency graph, which abstracts details of activity patterns in low-level signal and feature space. The activity labels are then autonomously learned by finding an optimal tiered mapping between the dependency graphs. Extensive experiments based on three public datasets demonstrate the superiority of ActiLabel over state-of-the-art transfer learning and deep learning methods.
Tasks Activity Recognition, Human Activity Recognition, Transfer Learning
Published 2020-03-16
URL https://arxiv.org/abs/2003.07415v1
PDF https://arxiv.org/pdf/2003.07415v1.pdf
PWC https://paperswithcode.com/paper/actilabel-a-combinatorial-transfer-learning
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Regularized Training and Tight Certification for Randomized Smoothed Classifier with Provable Robustness

Title Regularized Training and Tight Certification for Randomized Smoothed Classifier with Provable Robustness
Authors Huijie Feng, Chunpeng Wu, Guoyang Chen, Weifeng Zhang, Yang Ning
Abstract Recently smoothing deep neural network based classifiers via isotropic Gaussian perturbation is shown to be an effective and scalable way to provide state-of-the-art probabilistic robustness guarantee against $\ell_2$ norm bounded adversarial perturbations. However, how to train a good base classifier that is accurate and robust when smoothed has not been fully investigated. In this work, we derive a new regularized risk, in which the regularizer can adaptively encourage the accuracy and robustness of the smoothed counterpart when training the base classifier. It is computationally efficient and can be implemented in parallel with other empirical defense methods. We discuss how to implement it under both standard (non-adversarial) and adversarial training scheme. At the same time, we also design a new certification algorithm, which can leverage the regularization effect to provide tighter robustness lower bound that holds with high probability. Our extensive experimentation demonstrates the effectiveness of the proposed training and certification approaches on CIFAR-10 and ImageNet datasets.
Tasks
Published 2020-02-17
URL https://arxiv.org/abs/2002.07246v1
PDF https://arxiv.org/pdf/2002.07246v1.pdf
PWC https://paperswithcode.com/paper/regularized-training-and-tight-certification
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Declarative Memory-based Structure for the Representation of Text Data

Title Declarative Memory-based Structure for the Representation of Text Data
Authors Sumant Pushp, Pragya Kashmira, Shyamanta M Hazarika
Abstract In the era of intelligent computing, computational progress in text processing is an essential consideration. Many systems have been developed to process text over different languages. Though, there is considerable development, they still lack in understanding of the text, i.e., instead of keeping text as knowledge, many treat text as a data. In this work we introduce a text representation scheme which is influenced by human memory infrastructure. Since texts are declarative in nature, a structural organization would foster efficient computation over text. We exploit long term episodic memory to keep text information observed over time. This not only keep fragments of text in an organized fashion but also reduces redundancy and stores the temporal relation among them. Wordnet has been used to imitate semantic memory, which works at word level to facilitate the understanding about individual words within text. Experimental results of various operation performed over episodic memory and growth of knowledge infrastructure over time is reported.
Tasks
Published 2020-02-25
URL https://arxiv.org/abs/2002.10665v1
PDF https://arxiv.org/pdf/2002.10665v1.pdf
PWC https://paperswithcode.com/paper/declarative-memory-based-structure-for-the
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Multi-Task Siamese Neural Network for Improving Replay Attack Detection

Title Multi-Task Siamese Neural Network for Improving Replay Attack Detection
Authors Patrick von Platen, Fei Tao, Gokhan Tur
Abstract Automatic speaker verification systems are vulnerable to audio replay attacks which bypass security by replaying recordings of authorized speakers. Replay attack detection (RA) detection systems built upon Residual Neural Networks (ResNet)s have yielded astonishing results on the public benchmark ASVspoof 2019 Physical Access challenge. With most teams using fine-tuned feature extraction pipelines and model architectures, the generalizability of such systems remains questionable though. In this work, we analyse the effect of discriminative feature learning in a multi-task learning (MTL) setting can have on the generalizability and discriminability of RA detection systems. We use a popular ResNet architecture optimized by the cross-entropy criterion as our baseline and compare it to the same architecture optimized by MTL using Siamese Neural Networks (SNN). It can be shown that SNN outperform the baseline by relative 26.8 % Equal Error Rate (EER). We further enhance the model’s architecture and demonstrate that SNN with additional reconstruction loss yield another significant improvement of relative 13.8 % EER.
Tasks Multi-Task Learning, Speaker Verification
Published 2020-02-16
URL https://arxiv.org/abs/2002.07629v1
PDF https://arxiv.org/pdf/2002.07629v1.pdf
PWC https://paperswithcode.com/paper/multi-task-siamese-neural-network-for
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A Scalable Method for Scheduling Distributed Energy Resources using Parallelized Population-based Metaheuristics

Title A Scalable Method for Scheduling Distributed Energy Resources using Parallelized Population-based Metaheuristics
Authors Hatem Khalloof, Wilfried Jakob, Shadi Shahoud, Clemens Duepmeier, Veit Hagenmeyer
Abstract Recent years have seen an increasing integration of distributed renewable energy resources into existing electric power grids. Due to the uncertain nature of renewable energy resources, network operators are faced with new challenges in balancing load and generation. In order to meet the new requirements, intelligent distributed energy resource plants can be used. However, the calculation of an adequate schedule for the unit commitment of such distributed energy resources is a complex optimization problem which is typically too complex for standard optimization algorithms if large numbers of distributed energy resources are considered. For solving such complex optimization tasks, population-based metaheuristics – as, e.g., evolutionary algorithms – represent powerful alternatives. Admittedly, evolutionary algorithms do require lots of computational power for solving such problems in a timely manner. One promising solution for this performance problem is the parallelization of the usually time-consuming evaluation of alternative solutions. In the present paper, a new generic and highly scalable parallel method for unit commitment of distributed energy resources using metaheuristic algorithms is presented. It is based on microservices, container virtualization and the publish/subscribe messaging paradigm for scheduling distributed energy resources. Scalability and applicability of the proposed solution are evaluated by performing parallelized optimizations in a big data environment for three distinct distributed energy resource scheduling scenarios. Thereby, unlike all other optimization methods in the literature, the new method provides cluster or cloud parallelizability and is able to deal with a comparably large number of distributed energy resources. The application of the new proposed method results in very good performance for scaling up optimization speed.
Tasks
Published 2020-02-18
URL https://arxiv.org/abs/2002.07505v1
PDF https://arxiv.org/pdf/2002.07505v1.pdf
PWC https://paperswithcode.com/paper/a-scalable-method-for-scheduling-distributed
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CheckThat! at CLEF 2020: Enabling the Automatic Identification and Verification of Claims in Social Media

Title CheckThat! at CLEF 2020: Enabling the Automatic Identification and Verification of Claims in Social Media
Authors Alberto Barron-Cedeno, Tamer Elsayed, Preslav Nakov, Giovanni Da San Martino, Maram Hasanain, Reem Suwaileh, Fatima Haouari
Abstract We describe the third edition of the CheckThat! Lab, which is part of the 2020 Cross-Language Evaluation Forum (CLEF). CheckThat! proposes four complementary tasks and a related task from previous lab editions, offered in English, Arabic, and Spanish. Task 1 asks to predict which tweets in a Twitter stream are worth fact-checking. Task 2 asks to determine whether a claim posted in a tweet can be verified using a set of previously fact-checked claims. Task 3 asks to retrieve text snippets from a given set of Web pages that would be useful for verifying a target tweet’s claim. Task 4 asks to predict the veracity of a target tweet’s claim using a set of Web pages and potentially useful snippets in them. Finally, the lab offers a fifth task that asks to predict the check-worthiness of the claims made in English political debates and speeches. CheckThat! features a full evaluation framework. The evaluation is carried out using mean average precision or precision at rank k for ranking tasks, and F1 for classification tasks.
Tasks
Published 2020-01-21
URL https://arxiv.org/abs/2001.08546v1
PDF https://arxiv.org/pdf/2001.08546v1.pdf
PWC https://paperswithcode.com/paper/checkthat-at-clef-2020-enabling-the-automatic
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Efficient reinforcement learning control for continuum robots based on Inexplicit Prior Knowledge

Title Efficient reinforcement learning control for continuum robots based on Inexplicit Prior Knowledge
Authors Junjia Liu, Jiaying Shou, Zhuang Fu, Hangfei Zhou, Rongli Xie, Jun Zhang, Jian Fei, Yanna Zhao
Abstract Compared to rigid robots that are often studied in reinforcement learning, the physical characteristics of some sophisticated robots such as software or continuum are more complicated. Moreover, recent reinforcement learning methods are data-inefficient and can not be directly deployed to the robot without simulation. In this paper, we propose an efficient reinforcement learning method based on inexplicit prior knowledge in response to such problems. The method is firstly corroborated by simulation and employed directly in the real world. By using our method, we can achieve visual active tracking and distance maintenance of a tendon-driven robot which will be critical in minimally-invasive procedures.
Tasks
Published 2020-02-26
URL https://arxiv.org/abs/2002.11573v1
PDF https://arxiv.org/pdf/2002.11573v1.pdf
PWC https://paperswithcode.com/paper/efficient-reinforcement-learning-control-for
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Comparative analysis of machine learning models for Ammonia Capture of Ionic Liquids

Title Comparative analysis of machine learning models for Ammonia Capture of Ionic Liquids
Authors Shahaboddin Shamshirband, Narjes Nabipour, Masoud Hadipoor, Alireza Baghban, Amir Mosavi
Abstract Industry uses various solvents in the processes of refrigeration and ventilation. Among them, the Ionic liquids (ILs) as the relatively new solvents, are known for their proven eco-friendly characteristics. In this research, a comprehensive literature review was carried out to deliver an insight into the ILs and the prediction models used for estimating the ammonia solubility in ILs. Furthermore, a number of advanced machine learning methods, i.e. multilayer perceptron (MLP) and a combination of particle swarm optimization (PSO) and adaptive neuro-fuzzy inference system (ANFIS) models are used to estimate the solubility of ammonia in various ionic liquids. Affecting parameters were molecular weight, critical temperature and pressure of ILs. Furthermore, the salability is also predicted using the two-equation of states. Down the line, some comparisons were drawn between experimental and modeling results which is rarely done. The study shows that the equations of states are not able estimate the solubility of ammonia accurately, by contrast, artificial intelligence methods have produced promising results.
Tasks
Published 2020-02-19
URL https://arxiv.org/abs/2003.06224v1
PDF https://arxiv.org/pdf/2003.06224v1.pdf
PWC https://paperswithcode.com/paper/comparative-analysis-of-machine-learning
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The reproducing Stein kernel approach for post-hoc corrected sampling

Title The reproducing Stein kernel approach for post-hoc corrected sampling
Authors Liam Hodgkinson, Robert Salomone, Fred Roosta
Abstract Stein importance sampling is a widely applicable technique based on kernelized Stein discrepancy, which corrects the output of approximate sampling algorithms by reweighting the empirical distribution of the samples. A general analysis of this technique is conducted for the previously unconsidered setting where samples are obtained via the simulation of a Markov chain, and applies to an arbitrary underlying Polish space. We prove that Stein importance sampling yields consistent estimators for quantities related to a target distribution of interest by using samples obtained from a geometrically ergodic Markov chain with a possibly unknown invariant measure that differs from the desired target. The approach is shown to be valid under conditions that are satisfied for a large number of unadjusted samplers, and is capable of retaining consistency when data subsampling is used. Along the way, a universal theory of reproducing Stein kernels is established, which enables the construction of kernelized Stein discrepancy on general Polish spaces, and provides sufficient conditions for kernels to be convergence-determining on such spaces. These results are of independent interest for the development of future methodology based on kernelized Stein discrepancies.
Tasks
Published 2020-01-25
URL https://arxiv.org/abs/2001.09266v1
PDF https://arxiv.org/pdf/2001.09266v1.pdf
PWC https://paperswithcode.com/paper/the-reproducing-stein-kernel-approach-for
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Boosting rare benthic macroinvertebrates taxa identification with one-class classification

Title Boosting rare benthic macroinvertebrates taxa identification with one-class classification
Authors Fahad Sohrab, Jenni Raitoharju
Abstract Insect monitoring is crucial for understanding the consequences of rapid ecological changes, but taxa identification currently requires tedious manual expert work and cannot be scaled-up efficiently. Deep convolutional neural networks (CNNs), provide a viable way to significantly increase the biomonitoring volumes. However, taxa abundances are typically very imbalanced and the amounts of training images for the rarest classes are simply too low for deep CNNs. As a result, the samples from the rare classes are often completely missed, while detecting them has biological importance. In this paper, we propose combining the trained deep CNN with one-class classifiers to improve the rare species identification. One-class classification models are traditionally trained with much fewer samples and they can provide a mechanism to indicate samples potentially belonging to the rare classes for human inspection. Our experiments confirm that the proposed approach may indeed support moving towards partial automation of the taxa identification task.
Tasks
Published 2020-02-12
URL https://arxiv.org/abs/2002.10420v1
PDF https://arxiv.org/pdf/2002.10420v1.pdf
PWC https://paperswithcode.com/paper/boosting-rare-benthic-macroinvertebrates-taxa
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Online detection of local abrupt changes in high-dimensional Gaussian graphical models

Title Online detection of local abrupt changes in high-dimensional Gaussian graphical models
Authors Hossein Keshavarz, George Michailidis
Abstract The problem of identifying change points in high-dimensional Gaussian graphical models (GGMs) in an online fashion is of interest, due to new applications in biology, economics and social sciences. The offline version of the problem, where all the data are a priori available, has led to a number of methods and associated algorithms involving regularized loss functions. However, for the online version, there is currently only a single work in the literature that develops a sequential testing procedure and also studies its asymptotic false alarm probability and power. The latter test is best suited for the detection of change points driven by global changes in the structure of the precision matrix of the GGM, in the sense that many edges are involved. Nevertheless, in many practical settings the change point is driven by local changes, in the sense that only a small number of edges exhibit changes. To that end, we develop a novel test to address this problem that is based on the $\ell_\infty$ norm of the normalized covariance matrix of an appropriately selected portion of incoming data. The study of the asymptotic distribution of the proposed test statistic under the null (no presence of a change point) and the alternative (presence of a change point) hypotheses requires new technical tools that examine maxima of graph-dependent Gaussian random variables, and that of independent interest. It is further shown that these tools lead to the imposition of mild regularity conditions for key model parameters, instead of more stringent ones required by leveraging previously used tools in related problems in the literature. Numerical work on synthetic data illustrates the good performance of the proposed detection procedure both in terms of computational and statistical efficiency across numerous experimental settings.
Tasks
Published 2020-03-16
URL https://arxiv.org/abs/2003.06961v1
PDF https://arxiv.org/pdf/2003.06961v1.pdf
PWC https://paperswithcode.com/paper/online-detection-of-local-abrupt-changes-in
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Automating Botnet Detection with Graph Neural Networks

Title Automating Botnet Detection with Graph Neural Networks
Authors Jiawei Zhou, Zhiying Xu, Alexander M. Rush, Minlan Yu
Abstract Botnets are now a major source for many network attacks, such as DDoS attacks and spam. However, most traditional detection methods heavily rely on heuristically designed multi-stage detection criteria. In this paper, we consider the neural network design challenges of using modern deep learning techniques to learn policies for botnet detection automatically. To generate training data, we synthesize botnet connections with different underlying communication patterns overlaid on large-scale real networks as datasets. To capture the important hierarchical structure of centralized botnets and the fast-mixing structure for decentralized botnets, we tailor graph neural networks (GNN) to detect the properties of these structures. Experimental results show that GNNs are better able to capture botnet structure than previous non-learning methods when trained with appropriate data, and that deeper GNNs are crucial for learning difficult botnet topologies. We believe our data and studies can be useful for both the network security and graph learning communities.
Tasks
Published 2020-03-13
URL https://arxiv.org/abs/2003.06344v1
PDF https://arxiv.org/pdf/2003.06344v1.pdf
PWC https://paperswithcode.com/paper/automating-botnet-detection-with-graph-neural
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