1,720,990 research outputs found
Wykorzystanie wielomianów Viete’a-Lucasa w kryptografii asymetrycznej
No full textThis article presents a new cryptosystem using the newly defined Viete'a-Lucas polynomials over Zp. In the conducted analysis the correctness and safety of the cryptosystem was shown. The analysis also shows, that it is partially homomorphic. Furthermore a fast methods for calculation the value of the Viete-Lucas polynomials were described.W artykule tym przedstawiono kryptosystem, wykorzystując nowo zdefiniowane wielomiany Viete’a-Lucasa nad Zp. Następnie pokazano jego poprawność i bezpieczeństwo. Z przeprowadzonej analizy wynika również, że jest on częściowo homomorficzny. Ponadto opisano metody szybkiego obliczania wartości wielomianów Viete’a-Lucasa
Generowanie permutacji z wykorzystaniem odwzorowań chaotycznych
No full textPresented in this article algorithm is used to generate permutations of finite set basing upon chaotic maps. The modified version of this algorithm may be used to generate a permutation with previously predetermined weights.Prezentowany w tym artykule algorytm służy do generacji permutacji zbiorów skończonych, z wykorzystaniem odwzorowań chaotycznych. Jego zmodyfikowana wersja może być wykorzystana do generacji permutacji z zadanymi wcześniej wagami
Generation of pseudo-random numbers with the use of inverse chaotic transformation
No full textIn (Lawnik M., Generation of numbers with the distribution close to uniform with the use of chaotic maps, In: Obaidat M.S., Kacprzyk J., Ören T. (Ed.), International Conference on Simulation and Modeling Methodologies, Technologies and Applications (SIMULTECH) (28-30 August 2014, Vienna, Austria), SCITEPRESS, 2014) Lawnik discussed a method of generating pseudo-random numbers from uniform distribution with the use of adequate chaotic transformation. The method enables the “flattening” of continuous distributions to uniform one. In this paper a inverse process to the above-mentioned method is presented, and, in consequence, a new manner of generating pseudo-random numbers from a given continuous distribution. The method utilizes the frequency of the occurrence of successive branches of chaotic transformation in the process of “flattening”. To generate the values from the given distribution one discrete and one continuous value of a random variable are required. The presented method does not directly involve the knowledge of the density function or the cumulative distribution function, which is, undoubtedly, a great advantage in comparison with other well-known methods. The described method was analysed on the example of the standard normal distribution
The problem of the inverse Lyapunov exponent and its applications
Full text linkThe problem of the inverse Lyapunov exponent was formulated and solved, involving to find such chaotic transformation for which the value of the Lyapunov exponent is given in advance. The solution procedure was presented by a numerical example. Furthermore, applications of the discussed model in chaos based cryptography were discussed
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
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