1,720,956 research outputs found
Particle Swarm Optimization based on S-Boxes Generation
No full textThe generation of nonlinear substitutions (S-boxes) is an important task in the design of modern symmetric cryptoalgorithms. Various cryptographic properties of S-boxes (nonlinearity, balance, delta-uniformity, correlation and algebraic immunity, etc.) characterize their resistance to linear, differential, algebraic and other cryptanalysis methods. This article explores a computational particle swarm optimization (PSO) method as applied to the problem of generating nonlinear substitutions. Having a set of possible solutions (particles) and moving these particles in the search space, the PSO tries to improve the possible solution in terms of some quality indicator. We use nonlinearity, balance, delta uniformity, algebraic immunity and linear redundancy as the main indicators, and randomly generated S-boxes are used as a set of particles. This article shows several PSO modifications for generating nonlinear substitutions. At first, we reproduce the previously known PSO modification for generating S-boxes and show its low efficiency. At second, we propose our own PSO implementation and show that this method can actually generate substitutions with high cryptographic properties. The experimental results allow us to establish the influence of the size of the population of particles and the number of iterations of the outer loop on the efficiency of the heuristic generation of nonlinear substitutions. In addition, we explore the similarity of the generated substitution tables with the AES cipher S-box
Mathematical Model of the Reliability of a Computer System Operating in the Residual Class System, Based on Dynamic Redundancy
No full textThe article discusses a variant of the mathematical model of the reliability of a computer system (CS) operating in the residual class system (RNS), based on the use of dynamic redundancy. The calculation and comparative analysis of the reliability of the tripled computational structure in the positional number system with an ideal majority element and CS in the RNS with an ideal commutator is carried out. The analysis results showed the following. At the initial stage of the operation of computing systems, the reliability of the CS in the RNS with one control base is higher than the triple positional computing system. At the initial stage of the operation of computing systems, the reliability of the CS in the RNS with one control base is higher than the triple positional computing system. This presupposes the effective use of the COP in the RNS in systems and devices for short-term use. For example, in onboard computers of ballistic missiles and aircraft
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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