A fundamental challenge for engineering communication systems is the problem of transmitting information from the source to the receiver over a noisy channel. This same problem exists in a biological system. How can i...
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A fundamental challenge for engineering communication systems is the problem of transmitting information from the source to the receiver over a noisy channel. This same problem exists in a biological system. How can information required for the proper functioning of a cell, an organism, or a species be transmitted in an error introducing environment? Source codes (compression codes) and channel codes (error-correcting codes) address this problem in engineering communication systems. The ability to extend these information theory concepts to study information transmission in biological systems can contribute to the general understanding of biological communication mechanisms and extend the field of coding theory into the biological domain. In this work, we review and compare existing coding theoretic methods for modeling genetic systems. We introduce a new error-correcting code framework for understanding translation initiation, at the cellular level and present research results for Escherichia coli K-12. By studying translation initiation, we hope to gain insight into potential error-correcting aspects of genomic sequences and systems. Published by Elsevier Ltd. on behalf of The Franklin Institute.
We prove that the closest vector problem with preprocessing (CVPP) is NP-hardto approximate within any factor less than (5/3)~(1/2). More specifically, we show that thereexists a reduction from an NP-hard problem to t...
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We prove that the closest vector problem with preprocessing (CVPP) is NP-hardto approximate within any factor less than (5/3)~(1/2). More specifically, we show that thereexists a reduction from an NP-hard problem to the approximate closest vector problem such that thelattice depends only on the size of the original problem, and the specific instance is encodedsolely in the target vector. It follows that there are lattices for which the closest vector problemcannot be approximated within factors γ<(5/3)~(1/2) in polynomial time, no matter how the latticeis represented, unless NP is equal to P (or NP is contained in P/poly, in case of nonuniformsequences of lattices). The result easily extends to any l_p norm, for p≥ 1, showing that CVPP inthe l_p norm is hard to approximate within any factor γ < p (5/3)~(1/p). As an intermediate step,we establish analogous results for the nearest codeword problem with preprocessing (NCPP), provingthat for any finite field GF(q), NCPP over GF(q) is NP-hard to approximate within any factor lessthan 5/3.
A t-covering array is a collection of k vectors in a discrete space with the property that, in any t coordinate positions, all combinations of the coordinate values occur at least once. Such arrays have applications, ...
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A t-covering array is a collection of k vectors in a discrete space with the property that, in any t coordinate positions, all combinations of the coordinate values occur at least once. Such arrays have applications, for example, in software testing and data compression. Covering arrays are sometimes also called t-surjective arrays or qualitatively t-independent families;when t = 2 covering arrays are also called group covering designs or transversal covers. In an optimal covering array the number of vectors is minimized. Constructions for optimal covering arrays are known when t = 2 and the vectors are binary vectors, but in the other cases only upper and lower bounds are known. In this work a tabu search heuristic is used to construct covering arrays that improve on the previously known upper bounds on the sizes of optimal covering arrays. (C) 2003 Elsevier B.V. All rights reserved.
We prove that the closest vector problem with preprocessing (CVPP) is NP-hard to approximate within any factor less than √5/3. More specifically, we show that there exists a reduction from an NP-hard problem to the a...
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ISBN:
(纸本)0769514685
We prove that the closest vector problem with preprocessing (CVPP) is NP-hard to approximate within any factor less than √5/3. More specifically, we show that there exists a reduction from an NP-hard problem to the approximate closest vector problem such that the lattice depends only on the size of the original problem, and the specific instance is encoded solely in the target vector. It follows that there are lattices for which the closest vector problem cannot be approximated within factors γ<√5/3 in polynomial time, no matter how the lattice is represented, unless NP is equal to P (or NP is contained in P/poly, in case of nonuniform sequences of lattices). The result easily extends to any ℓp norm, for p≥1, showing that CVPP in the ℓp norm is hard to approximate within any factor γ
A fundamental challenge for engineering communication systems is the problem of transmitting information from the source to the receiver over a noisy channel. This same problem exists in a biological system. How can i...
详细信息
A fundamental challenge for engineering communication systems is the problem of transmitting information from the source to the receiver over a noisy channel. This same problem exists in a biological system. How can information required for the proper functioning of a cell, an organism, or a species be transmitted in an error introducing environment? Source codes (compression codes) and channel codes (error-correcting codes) address this problem in engineering communication systems. The ability to extend these information theory concepts to study information transmission in biological systems can contribute to the general understanding of biological communication mechanisms and extend the field of coding theory into the biological domain. In this work, we review and compare existing coding theoretic methods for modeling genetic systems. We introduce a new error-correcting code framework for understanding translation initiation, at the cellular level and present research results for Escherichia coli K-12. By studying translation initiation, we hope to gain insight into potential error-correcting aspects of genomic sequences and systems. Published by Elsevier Ltd. on behalf of The Franklin Institute.
This article reports the results of an experiment investigating the role of comic strips on ESL learners' reading comprehension. The students' proficiency levels were estimated, and students were organized int...
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This article reports the results of an experiment investigating the role of comic strips on ESL learners' reading comprehension. The students' proficiency levels were estimated, and students were organized into a low intermediate-level proficiency group (low-level students) and a high intermediate-level proficiency group (high-level Students). Students in each group were presented with either a high-level text or a low-level text, and the text was presented with or without a comic strip. Two-way and three-way ANOVAs run oil data from 107 immediate recall protocols reveal that the low-level Students receiving the high-level text with the comic strip scored significantly higher than their counterparts receiving the high-level text only. They also show that providing a comic strip with the high-level text did not enhance the high-level students' recall. In addition to offering pedagogical Suggestions, I discuss results in light of the dual coding theory and refer to other cognitive theories Such as mental model, noticing, and the repetition hypothesis.
This study examines two types of -ing subjects in English: the Late Modern English pattern the deceiving him was easy and constructions such as by trying to make her mother happy proved unlucky for Paul, which are bec...
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This study examines two types of -ing subjects in English: the Late Modern English pattern the deceiving him was easy and constructions such as by trying to make her mother happy proved unlucky for Paul, which are becoming frequent among American undergraduates. It is argued that the presence of the and by in both structures is prompted by the desire to provide explicit grammatical marking for clauses that, because of their role as pre-verbal subjects, are cognitively very complex. The paper discusses the ongoing grammaticalization of by Xing sequences and outlines the historical developments leading to the emergence of the pattern with an introductory the, for which it proposes an analysis in terms of Lass's (1990, 1997) concept of exaptation.
This article presents a rationale and description of GCS, or Grammatical coding System. GCS is a general-use grammatical coding system designed for research on the language of normal and language-impaired children or ...
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This article presents a rationale and description of GCS, or Grammatical coding System. GCS is a general-use grammatical coding system designed for research on the language of normal and language-impaired children or adults and is especially useful for studies in which a relatively large number of participants are involved. It implements recent theoretical developments in linguistics to characterize development and/or language disorder in children and adults. In addition to the coding system, a computerized method for reading coded transcripts and calculating relevant descriptive statistics is presented. A full coded transcription is included in the Appendix. A detailed GCS manual may be downloaded from ***/archive.
Hadamard matrices are defined, and their basic properties outlined. A survey of historical and recent literature follows, in which a number of existence theorems are examined and given context. Finally, a new result f...
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Hadamard matrices are defined, and their basic properties outlined. A survey of historical and recent literature follows, in which a number of existence theorems are examined and given context. Finally, a new result for Hadamard matrices over $_x001a__2$ is presented and given a graph-theoretic interpretation.
We derive uniform asymptotic expressions of some Abel sums appearing in some problems in coding theory and indicate the usefulness of these sums in other fields, like empirical processes, machine maintenance, analysis...
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We derive uniform asymptotic expressions of some Abel sums appearing in some problems in coding theory and indicate the usefulness of these sums in other fields, like empirical processes, machine maintenance, analysis of algorithms, probabilistic number theory, queuing models, etc. (C) 2001 Elsevier Science B.V. All rights reserved.
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