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International Conference on Data Engineering

作者： Antonio Cavalcante Araujo Neto Murilo Coelho Naldi Ricardo J. G. B. Campello Jö rg Sander Department of Computing Science University of Alberta Department of Computing Science Federal University of S&#x00E3 o Carlos School of Math. and Phys. Science University of Newcastle

ISBN: (数字)9781665408837

ISBN: (纸本)9781665408844

Several popular density-based methods for unsuper-vised and semi-supervised learning tasks, including clustering and classification, can be formulated as instances of a framework that is based on the processing of a minimum spanning tree of the data, where the edge weights correspond to a form of (unnormalized) density estimate w.r.t. a smoothing parameter $m_{pts}$ . While density-based methods are considered to be robust w.r.t. $m_{pts}$ in the sense that small changes in its value usually lead to slight or no changes in the resulting structure, wider ranges of $m_{pts}$ values may lead to different results that a user would like to analyze before choosing the most suitable value for a given data set or application. However, to explore multiple results for a range of $m_{pts}$ values, until recently, one had to re-run the density-based method for each value in the range independently, which is computationally inefficient. This paper proposes a new computationally efficient approach to compute multiple density-based minimum spanning trees w.r.t. a set of $m_{pts}$ values by leveraging a graph obtained from a single run of the density-based algorithm, without the need for re-runs of the original algorithm. We present theoretical and experimental results that show that our approach overcomes the drawbacks of the previous state-of-the-art, and it is considerably superior in runtime and graph size while being easier to implement. Our experimental evaluation using synthetic and real data shows that our strategy can lead to speed-up factors of hundreds to thousands of times on the computation of density-based minimum spanning trees.

关键词： Smoothing methods Runtime Semisupervised learning Data science Data engineering Real-time systems Computational efficiency

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Deep Learning-based Sentiment Classification: A Comparative Survey

arXiv

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arXiv 2023年

作者： Kayed, Mohamed Díaz Redondo, Rebeca P. Mabrouk, Alhassan Computer Science Department Faculty of Computers and Artificial Intelligence Beni-Suef University Egypt Information & Computing Lab AtlanTTIC Research Center Telecommunication Engineering School Universidade de Vigo Spain Math. and Computer Science Department Faculty of Science Beni-Suef University Egypt

Recently, Deep Learning (DL) approaches have been applied to solve the Sentiment Classification (SC) problem, which is a core task in reviews mining or Sentiment Analysis (SA). The performances of these approaches are affected by different factors. This paper addresses these factors and classifies them into three categories: data preparation based factors, feature representation based factors and the classification techniques based factors. The paper is a comprehensive literature-based survey that compares the performance of more than 100 DL-based SC approaches by using 21 public datasets of reviews given by customers within three specific application domains (products, movies and restaurants). These 21 datasets have different characteristics (balanced/imbalanced, size, etc.) to give a global vision for our study. The comparison explains how the proposed factors quantitatively affect the performance of the studied DL-based SC approaches. Copyright © 2023, The Authors. All rights reserved.

关键词： Sentiment analysis

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MIXUP-BASED DEEP METRIC LEARNING APPROACHES FOR INCOMPLETE SUPERVISION

arXiv

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arXiv 2022年

作者： Buris, Luiz H. Pedronette, Daniel C.G. Papa, Joao P. Almeida, Jurandy Carneiro, Gustavo Faria, Fabio Augusto Institute of Science and Technology Universidade Federal de São Paulo Brazil Depart. of Statistics Applied Math. and Computing São Paulo State University Brazil Department of Computing São Paulo State University Brazil Department of Computing Federal University of São Carlos Brazil Australian Institute for Machine Learning The University of Adelaide Australia

Deep learning architectures have achieved promising results in different areas (e.g., medicine, agriculture, and security). However, using those powerful techniques in many real applications becomes challenging due to the large labeled collections required during training. Several works have pursued solutions to overcome it by proposing strategies that can learn more for less, e.g., weakly and semi-supervised learning approaches. As these approaches do not usually address memorization and sensitivity to adversarial examples, this paper presents three deep metric learning approaches combined with Mixup for incomplete-supervision scenarios. We show that some state-of-the-art approaches in metric learning might not work well in such scenarios. Moreover, the proposed approaches outperform most of them in different datasets. Copyright © 2022, The Authors. All rights reserved.

关键词： Deep learning

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Texture synthesis via projection onto multiscale, multilayer statistics

arXiv

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arXiv 2021年

作者： He, Jieqian Hirn, Matthew Dept. of Computational Math. Science & Engineering Michigan State University East LansingMI United States Dept. of Computational Math. Science & Engineering Department of Mathematics Center for Quantum Computing Science & Engineering Michigan State University East LansingMI United States

We provide a new model for texture synthesis based on a multiscale, multilayer feature extractor. Within the model, textures are represented by a set of statistics computed from ReLU wavelet coefficients at different layers, scales and orientations. A new image is synthesized by matching the target statistics via an iterative projection algorithm. We explain the necessity of the different types of pre-defined wavelet filters used in our model and the advantages of multilayer structures for image synthesis. We demonstrate the power of our model by generating samples of high quality textures and providing insights into deep representations for texture images. Copyright © 2021, The Authors. All rights reserved.

关键词： Multilayers

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A second-order and nonuniform time-stepping maximum-principle preserving scheme for time-fractional Allen-Cahn equations

arXiv

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arXiv 2019年

作者： Liao, Hong-Lin Tang, Tao Zhou, Tao Department of Mathematics Nanjing University of Aeronautics and Astronautics Nanjing211106 China Department of Mathematics and International Center for Mathematics Southern University of Science and Technology Shenzhen Guangdong Province China Division of Science and Technology BNU-HKBU United International College Zhuhai Guangdong Province China NCMIS and LSEC Inst. of Compl. Math. and Sci./Engineering Computing Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing100190 China

In this work, we present a second-order nonuniform time-stepping scheme for the time-fractional Allen-Cahn equation. We show that the proposed scheme preserves the discrete maximum principle, and by using the convolution structure of consistency error, we present sharp maximum-norm error estimates which reflect the temporal regularity. As our analysis is built on nonuniform time steps, we may resolve the intrinsic initial singularity by using the graded meshes. Moreover, we propose an adaptive time-stepping strategy for large time simulations. Numerical experiments are presented to show the effectiveness of the proposed scheme. This seems to be the first second-order maximum principle preserving scheme for the time-fractional Allen-Cahn *** Codes 35Q99, 65M06, 65M12, 74A50 Copyright © 2019, The Authors. All rights reserved.

关键词： Maximum principle

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Schur multipliers and mixed unitary maps

arXiv

引用

arXiv 2018年

作者： Harris, Samuel J. Levene, Rupert H. Paulsen, Vern I. Plosker, Sarah Rahaman, Mizanur Institute for Quantum Computing Dept. of Pure Math. University of Waterloo WaterlooONN2L 3G1 Canada School of Mathematics and Statistics University College Dublin Belfield Dublin 4 Ireland Department of Mathematics and Computer Science Brandon University BrandonMBR7A 6A9 Canada

We consider the tensor product of the completely depolar- ising channel on d×d matrices with the map of Schur multiplication by a k ×k correlation matrix and characterise, via matrix theory methods, when such a map is a mixed (random) unitary channel. When d = 1, this recovers a result of O'Meara and Pereira, and for larger d is equiva- lent to a result of Haagerup and Musat that was originally obtained via the theory of factorisation through von Neumann algebras. We obtain a bound on the distance between a given correlation matrix for which this tensor product is nearly mixed unitary and a correlation matrix for which such a map is exactly mixed unitary. This bound allows us to give an elementary proof of another result of Haagerup and Musat about the closure of such correlation matrices without appealing to the theory of von Neumann algebras. Copyright © 2018, The Authors. All rights reserved.

关键词： Tensors

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Why Eve and Mallory love Android: An analysis of Android SSL (in)security 12

Why Eve and Mallory love Android: An analysis of Android SSL...

引用

2012 ACM Conference on Computer and Communications Security, CCS 2012

作者： Fahl, Sascha Harbach, Marian Muders, Thomas Smith, Matthew Baumgärtner, Lars Freisleben, Bernd Distributed Computing and Security Group Leibniz University of Hannover Hannover Germany Department of Math. and Computer Science Philipps University of Marburg Marburg Germany

ISBN: (纸本)9781450316507

Many Android apps have a legitimate need to communicate over the Internet and are then responsible for protecting potentially sensitive data during transit. This paper seeks to better understand the potential security threats posed by benign Android apps that use the SSL/TLS protocols to protect data they transmit. Since the lack of visual security indicators for SSL/TLS usage and the inadequate use of SSL/TLS can be exploited to launch Man-in-the-Middle (MITM) attacks, an analysis of 13,500 popular free apps downloaded from Google's Play Market is presented. We introduce MalloDroid, a tool to detect potential vulnerability against MITM attacks. Our analysis revealed that 1,074 (8.0%) of the apps examined contain SSL/TLS code that is potentially vulnerable to MITM attacks. Various forms of SSL/TLS misuse were discovered during a further manual audit of 100 selected apps that allowed us to successfully launch MITM attacks against 41 apps and gather a large variety of sensitive data. Furthermore, an online survey was conducted to evaluate users' perceptions of certificate warnings and HTTPS visual security indicators in Android's browser, showing that half of the 754 participating users were not able to correctly judge whether their browser session was protected by SSL/TLS or not. We conclude by considering the implications of these findings and discuss several countermeasures with which these problems could be alleviated. Copyright © 2012 ACM.

关键词： Sensitive data

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Using Ontology Patterns for Building a Reference Software Testing Ontology

Using Ontology Patterns for Building a Reference Software Te...

引用

International Workshop on Enterprise Distributed Object computing, EDOCW

作者： E.F. Souza R.A. Falbo N.L. Vijaykumar Applied Computing National Institute for Space Research INPE São José dos Campos SP Brazil Department of Computer Science Federal University of Espírito Santo UFES Vitória ES Brazil Lab. of Comp. and Applied Math. National Institute for Space Research INPE São José dos Campos SP Brazil

Software testing is a critical process for achieving product quality. Its importance is more and more recognized, and there is a growing concern in improving the accomplishment of this process. In this context, Knowledge Management emerges as an important supporting tool. However, managing relevant knowledge to reuse is difficult and it requires some means to represent and to associate semantics to a large volume of test information. In order to address this problem, we have developed a Reference Ontology on Software Testing (ROost). ROost is built reusing ontology patterns from the Software Process Ontology Pattern Language (SP-OPL). In this paper, we discuss how ROost was developed, and present a fragment of Roost that concerns with software testing process, its activities, artifacts, and procedures.

关键词： Ontologies Software testing Unified modeling language Software Standards Context

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Is Valiant-Vazirani's Isolation Probability Improvable?

Is Valiant-Vazirani's Isolation Probability Improvable?

引用

Annual IEEE Conference on Computational Complexity

作者： Holger Dell Valentine Kabanets Dieter van Melkebeek Osamu Watanabe Department of Computer Sciences University of Wisconsin Madison WI USA School of Computing Science Simon Fraser University Burnaby BC Canada Dept. of Math. Comput. Sci. Tokyo Institute of Technology Tokyo Japan

The Valiant-Vazirani Isolation Lemma [TCS, vol. 47, pp. 85-93, 1986] provides an efficient procedure for isolating a satisfying assignment of a given satisfiable circuit: Given a Boolean circuit C on n input variables, the procedure outputs a new circuit C' on the same n input variables such that (i) every satisfying assignment of C' also satisfies C, and (ii) if C is satisfiable, then C' has exactly one satisfying assignment. In particular, if C is unsatisfiable, then (i) implies that C' is unsatisfiable. The Valiant-Vazirani procedure is randomized, and when C is satisfiable it produces a uniquely satisfiable circuit C' with probability Ω(1/n). Is it possible to have an efficient deterministic witness-isolating procedure? Or, at least, is it possible to improve the success probability of a randomized procedure to a large constant? We argue that the answer is likely `No'. More precisely, we prove that there exists a non-uniform randomized polynomial-time witness-isolating procedure with success probability bigger than 2/3 if and only if NP ⊆ P/poly. Thus, an improved witness-isolating procedure would imply the collapse of the polynomial-time hierarchy. We establish similar results for other variants of witness isolation, such as reductions that remove all but an odd number of satisfying assignments of a satisfiable circuit. We also consider a blackbox setting of witness isolation that generalizes the setting of the Valiant-Vazirani Isolation Lemma, and give an upper bound of O(1/n) on the success probability for a natural class of randomized witness-isolating procedures.

关键词： Complexity theory Polynomials Educational institutions Standards Algorithm design and analysis Input variables Upper bound

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Comparative study of the algorithms for the weighted rectilinear min-sum facility location problem

Comparative study of the algorithms for the weighted rectili...

引用

International Conference on Computational Intelligence and Software Engineering

作者： Wang, Xiaodong Wang, Lei Wu, Yingjie College of Math. and Computing Quanzhou Normal University Quanzhou 362000 China College of Computing Georgia Institute of Technology Atlanta GA 30332 United States Computer Science Department Fuzhou University Fuzhou 350002 China

ISBN: (纸本)9781424453924

Given a set of n points in Rd with nonnegative weights, we consider the weighted rectilinear min-sum facility problem to minimize the sum of weighted rectilinear distance between the given points and a new added point. We present four simple algorithms for the weighted rectilinear min-sum facility location problem. The computational experiments demonstrate that the achieved results are not only of theoretical interest, but also that the techniques developed may actually lead to considerably faster algorithms. ©2010 IEEE.

关键词： Location

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