We put forward an ample framework for coding based on upper probabilities, or more generally on normalized monotone set-measures, and model accordingly noisy transmission channels and decoding errors. Two inverse prob...
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We put forward an ample framework for coding based on upper probabilities, or more generally on normalized monotone set-measures, and model accordingly noisy transmission channels and decoding errors. Two inverse problems are considered. In the first case, a decoder is given and one looks for channels of a specified family over which that decoder would work properly. In the second and more ambitious case, it is codes which are given, and one looks for channels over which those codes would ensure the required error correction capabilities. Upper probabilities allow for a solution of the two inverse problems in the case of usual codes based on checking Hamming distances between codewords: one can equivalently check suitable upper probabilities of the decoding errors. This soon extends to "odd" codeword distances for DNA strings as used in DNA word design, where instead, as we prove, not even the first unassuming inverse problem admits of a solution if one insists on channel models based on "usual" probabilities.
That semiosis is specific to the living world is the cornerstone of biosemiotics. For checking an information-theoretic interpretation of this statement already proposed at the 2009 Biosemiotics Gathering in Prague, i...
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That semiosis is specific to the living world is the cornerstone of biosemiotics. For checking an information-theoretic interpretation of this statement already proposed at the 2009 Biosemiotics Gathering in Prague, it is first attempted here to answer a question asked by Kupiec and Sonigo in Ni Dieu ni Gene (2000) on what differentiates living objects and those resulting from a geophysical process. Similar questions were asked by Schrodinger in his essay What Is Life? where the emphasis was laid on the relationship of the atomic scale of the genes and the macroscopic scale of living beings. This essay was published in 1944, before information was introduced as a scientific entity, at a time when DNA was not yet identified as the vector of heredity. We undertake answering some of these questions, arguing that the living world is made of organisms, i.e., of assemblies possessing in a genome the information needed for their replication and their maintenance while the inanimate world only contains aggregates. In short, a biological process keeps its order through the use of information. For defining order, it is proposed that an orderly object can be produced by a construction (e.g., the copy of a template) using available data within some given context. In other words, replicating an orderly object does not bring new information into its context. Order in this meaning appears as specific to the living world, at variance with the inanimate world which is basically disorderly. A better understanding of what separates the living world from the inanimate world results: the use of information is the distinguishing feature which defines their border. Any living thing contains a symbolic information, referred to as its genome, inscribed into DNA molecules. This genome can indeed be copied but, its support being embedded in the physical world, it incurs disturbances which result in symbol errors. Keeping its order thus needs endowing any genome with error correction ability:
The study of errors in gene translation has largely been confined to a small number of model organisms. We have examined all possible misreading errors at a defined codon in Mycobacterium smegmatis. Using a dual-lucif...
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The study of errors in gene translation has largely been confined to a small number of model organisms. We have examined all possible misreading errors at a defined codon in Mycobacterium smegmatis. Using a dual-luciferase gain of function reporter system that employs a mutated essential lysine in firefly luciferase, we accurately quantified mistranslation errors. Overall, accuracy of gene translation was comparable with Escherichia coli at <1/2000 errors/codon during exponential growth. Stationary phase was associated with a dramatic increase in misincorporation errors by Lys-tRNA(CUU)(Lys) at a subset of three codons, each with a single base changed from the AAG lysine codon. The maximum error rate detected was 0.2% with codon AUG. Treatment with streptomycin increased misreading errors at several codons associated in particular with U.U, G.U and C.U ***-codon mismatches, but oxidative stress did not change translational fidelity. Our study is the first comprehensive examination of misreading errors for a defined codon in mycobacteria. (C) 2015 Elsevier Ltd. All rights reserved.
This paper investigates the performance of wireless systems that employ finite-blocklength channel codes for transmission and operate under queuing constraints in the form of limitations on buffer overflow or delay vi...
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This paper investigates the performance of wireless systems that employ finite-blocklength channel codes for transmission and operate under queuing constraints in the form of limitations on buffer overflow or delay violation probabilities. A block fading model, in which fading stays constant in each coherence block and changes independently between blocks, is considered. It is assumed that channel coding is performed over multiple coherence blocks. A simple ARQ scheme with error-free feedback without any delay is considered. The channel coding rate with given maximal error probability is considered as the service rate and is incorporated into the effective capacity formulation, which characterizes the maximum constant arrival rate that can be supported under statistical queuing constraints. Performances of variable-rate and fixed-rate transmissions are studied. The optimum error probability for variable-rate and fixed-rate transmissions is shown to be unique. The limiting performance as the number of blocks increases is characterized. The tradeoffs and the interactions between the throughput, the number of coherence blocks over which channel coding is performed, error probabilities, channel coherence duration, and queuing constraints are identified.
A distributed space-time block code (STBC) based on a decode-and-forward (DF) protocol is proposed for two-path successive relaying. By making the two relay nodes transmit and listen in turn, the proposed distributed ...
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ISBN:
(纸本)9781424456383
A distributed space-time block code (STBC) based on a decode-and-forward (DF) protocol is proposed for two-path successive relaying. By making the two relay nodes transmit and listen in turn, the proposed distributed STBC can achieve not only full rate but also full diversity when the relay nodes can correctly decode the information symbols from the source node and when the inter-relay channels are sufficiently strong. We also analyze the situation when there are decoding errors at the relay nodes. We notice in this case full diversity will not be achieved. We then propose the application of selection relaying to the proposed distributed STBC to ensure that full rate and full diversity can still be obtained with decoding errors at the relay nodes.
In the presence of co-channel interference in cellular networks, interference mitigation by detecting the desired signal jointly with the interference promises considerable gain over the conventional way of handling t...
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ISBN:
(纸本)9781479944811
In the presence of co-channel interference in cellular networks, interference mitigation by detecting the desired signal jointly with the interference promises considerable gain over the conventional way of handling the interference as colored Gaussian. Even though such interference-aware detection can improve the performance, it requires some information on the interference, In particular, the modulation format of the interference has to be classified to this end, when it is not signaled by the network explicitly. This paper investigates interference modulation classification methods for interference-aware joint detection. We propose an iterative interference modulation classification algorithm that utilizes the decoded information of the desired signal in order to cancel the desired signal from the received signal. After the cancellation, the remaining signal can be treated as interference plus noise so that we can classify the modulation format of the interference at reduced complexity with small performance loss due to decoding errors.
Research on second language (L2) learners' aural decoding, a bottom-up process in listening comprehension, has not been given enough attention. To help researchers and teachers under-stand the aural decoding proce...
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Research on second language (L2) learners' aural decoding, a bottom-up process in listening comprehension, has not been given enough attention. To help researchers and teachers under-stand the aural decoding processing, this study investigates the relationship between aural decoding and L2 listening comprehension involving 42 second-year students majoring in English in a Chinese university. Findings indicate that: 1) there was a strong correlation between aural decoding and L2 listening comprehension (r = 0.69, p < .01);2) a threshold of aural decoding of around 80% of decoding scores may lead to good L2 listening comprehension;3) aural decoding scores may predict 46.9% of the variance in L2 listening comprehension. Additionally, results show that the most frequent decoding errors tend to be those which have no similarities to the input and those which are phonetically similar to the input. The most common reason leading to such errors seems to be that learners encountered words they had never heard before. Implica-tions for pedagogical practice in L2 classrooms are discussed.
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