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JOURNAL OF CRYPTOLOGY 2008年第1期21卷 27-51页

作者： Coppersmith, D. Coron, J. S. Grieu, F. Halevi, S. Jutla, C. Naccache, D. Stern, J. P. IBM Corp Thomas J Watson Res Ctr Yorktown Hts NY USA Univ Luxembourg Luxembourg Luxembourg Spirtech F-75006 Paris France IBM Corp TJ Watson Res Ctr Hawthorne NY USA Ecole Normale Super F-75231 Paris France Crytolog Int SAS F-75013 Paris France

We describe two different attacks against the ISO/IEC 9796-1 signature standard for RSA and Rabin. Both attacks consist in an existential forgery under a chosen-message attack: the attacker asks for the signature of some messages of his choice, and is then able to produce the signature of a message that was never signed by the legitimate signer. The first attack is a variant of Desmedt and Odlyzko's attack and requires a few hundreds of signatures. The second attack is more powerful and requires only three signatures.

关键词： cryptanalysis ISO/IEC 9796-1 signature standard RSA signatures Rabin signatures encoding scheme

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Improved protein secondary structure prediction using support vector machine with a new encoding scheme and an advanced tertiary classifier

IEEE TRANSACTIONS ON NANOBIOSCIENCE

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IEEE TRANSACTIONS ON NANOBIOSCIENCE 2004年第4期3卷 265-271页

作者： Hu, HJ Pan, Y Harrison, R Tai, PC Georgia State Univ Dept Comp Sci Atlanta GA 30303 USA Georgia State Univ Dept Biol Atlanta GA 30303 USA

Prediction of protein secondary structures is an important problem in bioinformatics and has many applications. The recent trend of secondary structure prediction studies is mostly based on the neural network or the support vector machine (SVM). The SVM method is a comparatively new learning system which has mostly been used in pattern recognition problems. In this study, SVM is used as a machine learning tool for the prediction of secondary structure and several encoding schemes, including orthogonal matrix, hydrophobicity matrix, BLOSUM62 substitution matrix, and combined matrix of these, are applied and optimized to improve the prediction accuracy. Also, the optimal window length for six SVM binary classifiers is established by testing different window sizes and our new encoding scheme is tested based on this optimal window size via sevenfold cross validation tests. The results show 2% increase in the accuracy of the binary classifiers when compared with the instances in which the classical orthogonal matrix is used. Finally, to combine the results of the six SVM binary classifiers, a new tertiary classifier which combines the results of one-versus-one binary classifiers is introduced and the performance is compared with those of existing tertiary classifiers. According to the results, the Q(3) prediction accuracy of new tertiary classifier reaches 78.8% and this is better than the best result reported in the literature.

关键词： binary classifier BLOSUM62 encoding scheme orthorgonal matrix Position Specific Scoring Matrix (PSSM) support vector machine (SVM) tertiary classifier

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Eliminating positional dependency in binary representation via redundancy

Eliminating positional dependency in binary representation v...

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IEEE Symposium on Foundations of Computational Intelligence

作者： Cheong, C. Y. Chiam, S. C. Goh, C. K. Natl Univ Singapore Dept Elect & Comp Engn 4Engn Dr 3 Singapore 117576 Singapore

ISBN: (纸本)9781424407033

Recent studies show that evolutionary algorithms are effective optimization tools for their success in solving real-world problem with complex and competing specifications. Although their performances are greatly influenced by the type of representation adopted, this choice often arises from intuition and guesswork due to the absence of proper guidelines and framework. This paper considers binary representation and presents a study on the key factors that affect its algorithmic performance. Subsequently, an encoding scheme is proposed to resolve the problem of positional dependency in binary coding, which is the commonly used genotype-phenotype mapping for this representation. This is achieved by introducing redundancy into the genotype-phenotype mapping, which will better preserve the similarities between the genotype and phenotype search space by resolving the exponential orderings between the alleles. Theoretical analysis and empirical study were conducted to investigate the characteristics of the proposed representation.

关键词： genetic algorithms search problems binary coding binary representation encoding scheme exponential orderings genotype-phenotype mapping positional dependency search space

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F-code: An optimized MDS array code

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3rd International Conference on Intelligent Computing

作者： Fan, Jianbo Shou, Lidan Dong, Jinxiang Ningbo Univ Technol Coll Electron & Informat Engn Ningbo 315016 Zhejiang Peoples R China Zhejiang Univ Coll Comp Sci & Technol Hangzhou 310027 Peoples R China

ISBN: (纸本)9783540741701

Based on the research of MDS array code of size nxn in distributed storage system, in this paper, we present a novel encoding scheme called the F-code and prove that the column distance of the F-code is 3, i.e. F-code is a MDS array code given that odd number n is greater than 3 and does not include factor 3. And we also implement a novel decoding algorithm of the F-code. The algorithm only needs two decoding chains in each linear equation group and is able to recover all unknown symbols on two erasure columns. The analysis of F-code shows that our method extends the range of number n in nxn MDS array code and gets lower/reduction algorithmic complexity. Therefore, the reliability of a distributed storage system that features the F-code can be effectively reinforced.

关键词： distributed storage system the F-code encoding scheme MDS property decoding algorithm

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Protein Secondary Structure Prediction Using Support Vector Machines, Nueral Networks and Genetic Algorithms

Protein Secondary Structure Prediction Using Support Vector ...

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作者： Anjum B. Reyaz-Ahmed Georgia State University

学位级别：硕士

Bioinformatics techniques to protein secondary structure prediction mostly depend on the information available in amino acid sequence. Support vector machines (SVM) have shown strong generalization ability in a number of application areas, including protein structure prediction. In this study, a new sliding window scheme is introduced with multiple windows to form the protein data for training and testing SVM. Orthogonal encoding scheme coupled with BLOSUM62 matrix is used to make the prediction. First the prediction of binary classifiers using multiple windows is compared with single window scheme, the results shows single window not to be good in all cases. Two new classifiers are introduced for effective tertiary classification. This new classifiers use neural networks and genetic algorithms to optimize the accuracy of the tertiary classifier. The accuracy level of the new architectures are determined and compared with other studies. The tertiary architecture is better than most available techniques.

关键词： Binary classifier BLOSUM62 encoding scheme orthogonal profile support vector machine (SVM) tertiary classifier

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An efficient Method for Protein Secondary Structure Prediction

An efficient Method for Protein Secondary Structure Predicti...

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The 1st International Conference on Bioinformatics and Biomedical Engineering(iCBBE 2007)(首届IEEE生物信息与生物医学工程国际会议)

作者： Tao WU Junjun MAO Ling ZHANG State Key Laboratory for Novel Software Technology Department of Computer Science & TechnologyNanj School of Mathematics and Computational Science Anhui University Hefei 230039 R.P.China Key Lab IC&SP Anhui University Hefei 230039 R.P.China

The secondary structure prediction of protein plays an important role to obtain its tertiary structure and function. In the past thirty years, a huge amount of algorithms have been employed to this task. The better predicators are based on machine learning techniques, especially based on neural networks. But the architecture of neural network is hard to define, and the training process is time-consuming. In this paper,a constructive machine learning approach is used to predict protein secondary structure with five different encoding schemes,the results show that the constructive algorithm can achieve high predicting accuracies and the encoding schemes have influence on predicting result.

关键词： protein secondary structure prediction constructive machine learning spherical neighborhood encoding scheme

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Effects of the eencoding scheme on the perceived compressed video quality transmitted over lossy IP networks

Effects of the eencoding scheme on the perceived compressed ...

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International Conference on Information and Technology

作者： Shmueli, Ron Hadar, Ofer Huber, Revital Maltz, Masha Huber, Merav Ben Gurion Univ Negev Dept Commun Syst Engn Dept IL-84105 Beer Sheva Israel Ben Gurion Univ Negev Dept Elect & Comp Engn IL-84105 Beer Sheva Israel Ben Gurion Univ Negev Dept Ind Engn & Management IL-84105 Beer Sheva Israel

ISBN: (纸本)9781424408580

In this paper we analyze the viewer-perceived quality of a compressed video stream, which is transmitted over a lossy IP network with QoS (quality of service) mechanism. We demonstrate that when jointly considering the impact of coding bit rate, packet loss ratio and video characteristics, there is an optimal encoding scheme, which maximizes the viewer-perceived quality. The video content, the compression and the transmission are represented in a vector X of d parameters. Based on the subjective tests, we obtain a set of observation pairs of labeled samples Pi = {Xi,Qi}, where Qi is the quality class related to the vector of input parameters Xi. We introduce a novel method to predict the optimal encoding scheme based on canonical discriminant analysis (CDA) for feature classification. Keywords: Subjective Testing, Video QoS,IP, Compression, Video Quality, MPEG, CDA, PLR, MANOVA, subjective tests, encoding scheme, perceived quality.

关键词： CDA Compression IP MANOVA MPEG PLR Subjective Testing Video QoS Video Quality encoding scheme perceived quality subjective tests Subjective testing Coding systems Moving Pictures Experts Group Video compression Internet Protocol networks quality class compression

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Effects of compression parameters on the perceived quality of video stream over a lossy Internet protocol network

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OPTICAL ENGINEERING 2006年第8期45卷 087003-1-087003页

作者： Hadar, Ofer Shmueli, Ron Huber, Revital Huber, Merav Ben Gurion Univ Negev Commun Syst Engn Dept IL-84105 Beer Sheva Israel Ben Gurion Univ Negev Dept Elect & Comp Engn IL-84105 Beer Sheva Israel

We analyze the connection between viewer-perceived quality and encoding schemes. The encoding schemes depend on transmission bit-rate, MPEG compression depth, frame size and frame rate in a constant bit-rate (CBR) video transmission of a MPEG-2 video sequence. The compressed video sequence is transmitted over a lossy communication network with quality of service (QoS) and a certain Internet (IP) loss model. On the end-user side, viewer-perceived quality depends on changes in the network conditions, the video compression, and the video content complexity. We demonstrate that, when jointly considering the impact of coding bit rate, packet loss, and video complexity, there is an optimal encoding scheme, which also depends on the video content. We use a set of subjective tests to demonstrate that this optimal encoding scheme maximizes the viewer-perceived quality. (c) 2006 Society of Photo-Optical Instrumentation Engineers.

关键词： Motion Picture Experts Group subjective tests quality of service compression encoding scheme Internet protocol perceived quality packet loss ratio

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Digital text watermarking: Secure content delivery and data hiding in digital documents

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IEEE AEROSPACE AND ELECTRONIC SYSTEMS MAGAZINE 2006年第11期21卷 18-21页

作者： Qadir, Muhammad Abdul Ahmad, Ishtiaq Mohammad Ali Jinnah Univ Fac Sci & Engn Islamabad Pakistan

Secure communication of data over public channels is one of the most important challenges. Both the activities to secure contents and to break security are very hot. In order to reduce the chances of attack, security needs to be made invisible. The needs to preserve originality, ownership information, and integrity of text documents in a way that cannot be identified by everyone is being felt badly. Watermarking of the documents is a step toward achieving these objectives. However, to watermark a plain text document (ASCII) in a way that the original text will not change (and it would be very difficult to break it), is a great challenge. We have developed a novel encoding scheme which can be used to insert information in plain text without changing the text. A system has been developed based upon this encoding scheme. This paper describes the system and demonstrates its workings.

关键词： data encapsulation document handling encoding security of data watermarking data hiding data secure communication digital documents digital text watermarking encoding scheme public channels secure content delivery Hidden data Data Security Content distribution data encapsulation texts Coding systems electronic document handling coding Watermarking cleartext

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Properties of symmetric fitness functions 06

Properties of symmetric fitness functions

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8th Annual Genetic and Evolutionary Computation Conference

作者： Choi, Sung-Soon Kwon, Yung-Keun Moon, Byung-Ro Seoul Natl Univ Sch Comp Sci & Engn Seoul 151744 South Korea

ISBN: (纸本)9781595931863

The properties of symmetric fitness functions are investigated. We show that a well-known encoding scheme inducing symmetric functions has the non-synonymous property and the search spaces obtained from symmetric functions have the zero-correlation structures. The Walsh analysis reveals the properties of symmetric functions related to additive separability, problem difficulty measures and so on. Our results support the claim of other researchers that the search spaces with symmetry induce relatively difficult problems. The results also present some limitations of existing problem difficulty measures for symmetric fitness functions.

关键词： symmetric fitness functions encoding scheme search space analysis problem difficulty measures Walsh analysis

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