2,747 research outputs found

    New Combinatorial Construction Techniques for Low-Density Parity-Check Codes and Systematic Repeat-Accumulate Codes

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    This paper presents several new construction techniques for low-density parity-check (LDPC) and systematic repeat-accumulate (RA) codes. Based on specific classes of combinatorial designs, the improved code design focuses on high-rate structured codes with constant column weights 3 and higher. The proposed codes are efficiently encodable and exhibit good structural properties. Experimental results on decoding performance with the sum-product algorithm show that the novel codes offer substantial practical application potential, for instance, in high-speed applications in magnetic recording and optical communications channels.Comment: 10 pages; to appear in "IEEE Transactions on Communications

    Is new spread of the European beaver in Pannonian basin an evidence of the species recovery?

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    Abstract: During fieldwork from 6 June to 20 July 2016, the first records of the European beaver (Castor fiber) in south-eastern Slovakia were made. Beavers are mainly nocturnal animals, and as such, they are rarely observed; therefore, our observations were based on searching for beaver presence signs: damaged trees, dams, signs of food consumption (chewed/felled trees) and footprints in the mud. The southern part of the Košická kotlina basin, from the city of Košice down to the state border and the surrounding villages in Hungary, was checked. We found two beaver locations via feeding signs in the vicinity of the Slovakia–Hungary state border, at the villages of Milhosť (Miglécnémeti) and Buzica (Buzita), in Slovakia. According to our calculations, the present total beaver population in Hungary is between 4,000 and 5,000 and 14,600–18,300 beavers with potential support. For Slovakia, we estimated the potential population size to be 7,700–9,600. Our findings in northern Pannonian lowland (Slovakia–Hungary border) are an important evidence of beaver expansion. Although we don’t know the exact origin of investigated population, these new records indicate the possibility of merging the populations of different origin, which could enable gene flow and increase the genetic diversity. This could lead to improved recovery of species and its stabilisation in nature. However, it is necessary to carry out a detailed investigation of the presence of beaver in these regions in future

    The Relevance of the Centrality and Content of Religiosity for Explaining Islamophobia in Switzerland

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    Research on Islamophobia in Switzerland, and on the role of religiosity in relation to Islamophobia, is in its infancy. Against this background, we analyzed data from an online survey conducted in Switzerland on “Xenosophia and Xenophobia in and between Abrahamic religions”. The results of a multivariate analysis revealed that, besides right-wing authoritarianism, social dominance orientation, and political orientation, indicators related to religion play a crucial role. We found that the greater the role of religion, and the more central it is for the individual, the more likely it is that the individual has a positive view of Islam. We claim that a person’s level of religiosity is accompanied by her adoption of religious values, such as neighbourliness and tolerance, and that the more religious individuals are, the more likely they are occupied with different religions, which leads to tolerance as long as it is not accompanied by a fundamentalist religious orientation. Also relevant is that the preference for the state to have a secularized relationship with religion is accompanied by a fear of Islam. We propose that studies on Islamophobia, as well as on other prejudices, should use differentiated measures for religiosity; the Centrality of Religiosity Scale (CRS) turned out to be a reliable instrument of measurement in this regard

    Methods for measuring the citations and productivity of scientists across time and discipline

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    Publication statistics are ubiquitous in the ratings of scientific achievement, with citation counts and paper tallies factoring into an individual's consideration for postdoctoral positions, junior faculty, tenure, and even visa status for international scientists. Citation statistics are designed to quantify individual career achievement, both at the level of a single publication, and over an individual's entire career. While some academic careers are defined by a few significant papers (possibly out of many), other academic careers are defined by the cumulative contribution made by the author's publications to the body of science. Several metrics have been formulated to quantify an individual's publication career, yet none of these metrics account for the dependence of citation counts and journal size on time. In this paper, we normalize publication metrics across both time and discipline in order to achieve a universal framework for analyzing and comparing scientific achievement. We study the publication careers of individual authors over the 50-year period 1958-2008 within six high-impact journals: CELL, the New England Journal of Medicine (NEJM), Nature, the Proceedings of the National Academy of Science (PNAS), Physical Review Letters (PRL), and Science. In comparing the achievement of authors within each journal, we uncover quantifiable statistical regularity in the probability density function (pdf) of scientific achievement across both time and discipline. The universal distribution of career success within these arenas for publication raises the possibility that a fundamental driving force underlying scientific achievement is the competitive nature of scientific advancement.Comment: 25 pages in 1 Column Preprint format, 7 Figures, 4 Tables. Version II: changes made in response to referee comments. Note: change in definition of "Paper shares.

    Pion form factor in QCD sum rules, local duality approach, and O(A_2) fractional analytic perturbation theory

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    Using the results on the electromagnetic pion Form Factor (FF) obtained in the O(αs)O(\alpha_s) QCD sum rules with non-local condensates \cite{BPS09} we determine the effective continuum threshold for the local duality approach. Then we apply it to construct the O(αs2)O(\alpha_s^2) estimation of the pion FF in the framework of the fractional analytic perturbation theory.Comment: 4 pages, 2 figures, invited talk at the 3rd Joint International Hadron Structure'09 Conference, Tatranska Strba (Slovak Republic), Aug. 30--Sept. 3, 200
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