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17th International Conference on Computer and information Technology (ICCIT)

作者： Kabir, Sohag Azad, Tanzima Alam, A. S. M. Ashraful Kaykobad, Mohammad Univ Hull Dept Comp Sci Kingston Upon Hull HU6 7RX N Humberside England Bangladesh Univ Engn & Technol Dept Comp Sci & Engn Dhaka Bangladesh Univ Otago Dept Comp Sci Dunedin New Zealand

ISBN: (纸本)9781479962884

Classical Huffman codes have a very good compression performance over traditional systems. Yet, more efficient encoding is possible by considering and applying techniques that treat the binary bits differently considering requirement of storage space, energy consumption, speed of execution and so on. Future transmission systems are likely to be more efficient in many aspects. These systems will consume fewer resources to transmit or store one of the binary bits. Hence, an unequal bit cost would necessitate a different approach to producing an optimal encoding scheme. This work proposes an algorithm, which considers unequal bit-cost contribution to a message. Our experiment yields that the proposed algorithm reduces overall communication cost and improves compression ratio considerably in comparison to classical Huffman codes. This unequal bit cost technique produces a variant of Huffman Code that reduces total cost of the compressed message.

关键词： Huffman coding Source coding coding and information theory Data Compression

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Generational analysis of tension and entropy in data structures: impact on automatic data integration and on the semantic web

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KNOWLEDGE AND information SYSTEMS 2011年第1期28卷 175-196页

作者： Rohn, Eli CogniMax LLC Highland Pk NJ 08904 USA

The move toward automatic data integration from autonomous and heterogeneous sources is viewed as a transition from a closed to an open system, which is in essence an adaptive information processing system. Data definition languages from various computing eras spanning almost 50 years to date are examined, assessing if they have moved from closed systems to open systems paradigm. The study proves that contemporary data definition languages are indistinguishable from older ones using measurements of Variety, Tension and Entropy, three characteristics of complex adaptive systems (CAS). The conclusion is that even contemporary data definition languages designed for such integration exhibit closed systems characteristics along with open systems aspirations only. Plenty of good will is insufficient to make them more suitable for automatic data integration than their oldest predecessors. A previous report and these new findings set the stage for the development and proposal of a mathematically sound data definition language based on CAS, thus potentially making it better suited for automatic data integration from autonomous heterogeneous sources.

关键词： Data integration Semantic web Data definition languages Law of requisite variety coding and information theory Complex adaptive systems Variety Regulator Tension Entropy GlossoMote

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Generational analysis of variety in data structures: impact on automatic data integration and on the semantic web

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KNOWLEDGE AND information SYSTEMS 2010年第2期24卷 283-304页

作者： Rohn, Eli New Jersey Inst Technol Dept Informat Syst Newark NJ 07102 USA

We examine data definition languages (DDLs) from various computing era spanning almost 50 years to date. We prove that contemporary DDLs are indistinguishable from older ones using Zipf distribution of words, Zipf distributions of meanings, and information theory. None addresses the Law of Requisite Variety, which is necessary for enabling automatic data integration from autonomous heterogeneous data sources and for the realization of the Semantic Web. The growth of the entire computing industry is hampered by the lack of progress in the development of DDLs suitable for these two goals. Our findings set the stage for the future development of a mathematically sound DDL better suited for the aforementioned purposes.

关键词： Data integration Semantic web Data definition languages Zipf distribution Law of requisite variety coding and information theory information systems models and principles

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Implementing the LZ-index: theory versus Practice

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ACM Journal of Experimental Algorithmics 2009年第PP1.2–1.49期13卷 1.2-1.49页

作者： Navarro, Gonzalo Department of Computer Science University of Chile Santiago Blanco Encalada 2120 Chile

The LZ-index is a theoretical proposal of a lightweight data structure for text indexing, based on the Ziv-Lempel trie. If a text of u characters over an alphabet of size σ is compressible to n symbols using the LZ78 algorithm, then the LZ-index takes 4n log₂ n(1 + o(1)) bits of space (that is, 4 times the entropy of the text) and reports the R occurrences of a pattern of length m in worst case time O(m³logσ + (m + R)logn). In this paper we face the challenge of obtaining a practical implementation of the LZ-index, which is not at all straightforward from the theoretical proposal. We end up with a prototype that takes the promised space and has average search time [formula omitted]. This prototype is shown to be faster than other competing approaches when we take into account the time to report the positions or text contexts of the occurrences found. We show in detail the process of implementing the index, which involves interesting lessons of theory versus practice. Categories and Subject Descriptors: F.2.2 [Analysis of Algorithms and Problem Complexity]: Nonnumerical algorithms and problems—Pattern matching, computations on discrete structures, sorting and searching;H.2.1 [Database Management]: Physical design—Access methods;H.3.2 [information Storage and Retrieval]: information storage—File organization;H.3.3 [information Storage and Retrieval]: information search and retrieval—Search process. © 2009, ACM. All rights reserved.

关键词： Algorithms coding and information theory data storage representations Data structures indexing methods textual databases

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Compressed text indexes: From theory to practice

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ACM Journal of Experimental Algorithmics 2008年第PP1.12–1.31期13卷 1.12–1.31页

作者： Ferragina, Paolo González, Rodrigo Navarro, Gonzalo Venturini, Rossano University of Pisa Italy University of Chile Chile

A compressed full-text self-index represents a text in a compressed form and still answers queries efficiently. This represents a significant advancement over the (full-)text indexing techniques of the previous decade, whose indexes required several times the size of the text. Although it is relatively new, this algorithmic technology has matured up to a point where theoretical research is giving way to practical developments. Nonetheless this requires significant programming skills, a deep engineering effort, and a strong algorithmic background to dig into the research results. To date only isolated implementations and focused comparisons of compressed indexes have been reported, and they missed a common API, which prevented their re-use or deployment within other applications. The goal of this article is to fill this gap. First, we present the existing implementations of compressed indexes from a practitioner's point of view. Second, we introduce the Pizza & Chili site, which offers tuned implementations and a standardized API for the most successful compressed full-text self-indexes, together with effective test-beds and scripts for their automatic validation and test. Third, we show the results of our extensive experiments on these codes with the aim of demonstrating the practical relevance of this novel algorithmic technology. Categories and Subject Descriptors: F.2.2 [Analysis of Algorithms and Problem Complexity]: Nonnumerical Algorithms and Problems-Pattern matching, computations on discrete structures, sorting and searching;H.2.1 [Database Management]: Physical Design-Access methods;H.3.2 [information Storage and Retrieval]: information Storage-File organization;H.3.3 [information Storage and Retrieval]: information Search and Retrieval-Search process General Terms: Algorithms Additional Key Words and Phrases: Text indexing, text compression, data structures, data storage representation, coding and information theory, indexing methods, textual databases, bi

关键词： Text indexing bioinformatics databases coding and information theory data storage representation data structures indexing methods text compression textual databases

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Lightweight error correction coding for system-level interconnects

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IEEE TRANSACTIONS ON COMPUTERS 2007年第3期56卷 289-304页

作者： Bakos, Jason D. Chiarulli, Donald M. Levitan, Steven P. Univ S Carolina Dept Comp Sci & Engn Columbia SC 29208 USA Univ Pittsburgh Dept Comp Sci Pittsburgh PA 15260 USA Univ Pittsburgh Dept Elect & Comp Engn Pittsburgh PA 15260 USA

"Lightweight Hierarchical Error Control coding ( LHECC)" is a new class of nonlinear block codes that is designed to increase noise immunity and decrease error rate for high-performance chip-to-chip and on-chip interconnects. LHECC is designed such that its corresponding encoder and decoder logic may be tightly integrated into compact, high-speed, and low-latency I/O interfaces. LHECC operates over a new channel technology called Multi-Bit Differential Signaling ( MBDS). MBDS channels utilize a physical-layer channel code called "N choose M ( nCm)" encoding, where each channel is restricted to a symbol set such that half of the bits in each symbol are set to one. These symbol sets have properties that are utilized by LHECC to achieve error correction capability while requiring low or zero relative information overhead. In addition, these codes may be designed such that the latency and size of the corresponding decoders are tightly bounded. The effectiveness of these codes is demonstrated by modeling error behavior of MBDS interconnects over a range of transmission rates and noise characteristics.

关键词： interconnections (subsystems) interconnection architectures code design coding tools and techniques coding and information theory error control codes

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Analysis of errors and erasures in parity sharing RS codecs

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IEEE TRANSACTIONS ON COMPUTERS 2007年第12期56卷 1721-1726页

作者： Cardarilli, G. C. Pontarelli, S. Re, M. Salsano, A. Univ Rome Dept Elect Engn Rome Italy

Reed Solomon (RS) codes are widely used to protect information from errors in transmission and storage systems. Most of the RS codes are based on GFd(2(8)) Galois Fields and use a byte to encode a symbol providing codewords up to 255 symbols. Codewords with more than 255 symbols can be obtained by using GFd(2(m)) Galois Fields with m > 8, but this choice increases the complexity of the encoding and decoding algorithms. This limitation can be superseded by introducing Parity Sharing ( PS) RS codes that are characterized by a greater flexibility in terms of design parameters. Consequently, a designer can choose between different PS code implementations in order to meet requirements such as Bit Error Rate (BER), hardware complexity, speed, and throughput. This paper analyzes the performance of PS codes in terms of BER with respect to the code parameters, taking into account either random error or erasure rates as two independent probabilities. This approach provides an evaluation that is independent of the communication channel characteristics and extends the results to memory systems in which permanent faults and transient faults can be modeled, respectively, as erasures and random errors. The paper also provides hardware implementations of the PS encoder and decoder and discusses their performances in terms of hardware complexity, speed, and throughput.

关键词： reliability testing and fault tolerance error control codes coding and information theory

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The quest for error correction in biology

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IEEE ENGINEERING IN MEDICINE AND BIOLOGY MAGAZINE 2006年第1期25卷 46-53页

作者： Gupta, MK Queens Univ Dept Math & Stat Kingston ON K7L 3N6 Canada

The goal of this article is to give a brief account of the recent developments in codes and biology. With the increasing understanding of biology and with the advancement of sequencing technology, the whole human genome is stretched out before us. There is a need to look again with these new information for the applications of coding and information theory to biology. This paper focuses on the existence of error correction in biological information processing.

关键词： error correction codes genetics molecular biophysics biological information processing codes error correction human genome information theory sequencing technology error correction biological information processing coding and information theory information theory Biological Science Disciplines molecular biology Codes Genetics Human Genome biology

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Efficient m-ary balanced codes which are invariant under symbol permutation

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IEEE TRANSACTIONS ON COMPUTERS 2006年第8期55卷 929-946页

作者： Mascella, Raffaele Tallini, Luca G. Univ Teramo Dipartimento Sci Comunicaz I-64100 Teramo Italy

A symbol permutation invariant balanced (SPI-balanced) code over the alphabet ZZ(m) = {0, 1,..., m - 1} is a block code over ZZm such that each alphabet symbol occurs as many times as any other symbol in every codeword. For this reason, every permutation among the symbols of the alphabet changes an SPI-balanced code into an SPI-balanced code. This means that SPI-balanced words are "the most balanced" among all possible m-ary balanced word types and this property makes them very attractive from the application perspective. In particular, they can be used to achieve m-ary DC-free communication, to detect/correct asymmetric/unidirectional errors on the m-ary asymmetric/unidirectional channel, to achieve delay-insensitive communication, to maintain data integrity in digital optical disks, and so on. This paper gives some efficient methods to convert ( encode) m-ary information sequences into m-ary SPI-balanced codes whose redundancy is equal to roughly double the minimum possible redundancy r(min). It is proven that r(min) similar or equal to vertical bar(m - 1)/2] log(m)n - (1/2) [1/log(2 pi)m)m-(1/log(2 pi)m) for any code which converts k information digits into an SPI-balanced code of length n = k + r. For example, the first method given in the paper encodes k information digits into an SPI-balanced code of length n = k + r, with r = (m - 1) log(m) k + O(m log(m) log(m) k). A second method is a recursive method, which uses the first as base code and encodes k digits into an SPI-balanced code of length n = k + r, with r similar or equal to (m - 1) log(m) n - log(m) [(m - 1)!].

关键词： coding and information theory error control codes balanced codes constant weight codes digital communication m-ary communication line codes DC-free communication delay-insensitive communication

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Video coding with Superimposed Motion-Compensated Signals 1

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丛书名： The Springer International Series in Engineering and Computer Science

2004年

作者： Markus Flierl Bernd Girod

ISBN: (数字)9781402077654

ISBN: (纸本)9781402077593;9781441954329

Appendices 133 A Mathematical Results 133 A.1 Singularities of the Displacement Error Covariance Matrix 133 A.2 A Class of Matrices and their Eigenvalues 134 A.3 Inverse of the Power Spectral Density Matrix 134 A.4 Power Spectral Density of a Frame 136 Glossary 137 References 141 Index 159 Preface This book aims to capture recent advances in motion compensation for - ficient video compression. It investigates linearly combined motion comp- sated signals and generalizes the well known superposition for bidirectional prediction in B-pictures. The number of superimposed signals and the sel- tion of reference pictures will be important aspects of the discussion. The application oriented part of the book employs this concept to the well known ITU-T Recommendation H.263 and continues with the improvements by superimposed motion-compensated signals for the emerging ITU-T R- ommendation H.264 and ISO/IEC MPEG-4 (Part 10). In addition, it discusses a new approach for wavelet-based video coding. This technology is currently investigated by MPEG to develop a new video compression standard for the mid-term future.

关键词： Computer and information Systems Applications Electrical and Electronic Engineering Computer Vision Multimedia information Systems Signal, Speech and Image Processing coding and information theory

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