28,562 research outputs found

    Using DDC to create a visual knowledge map as an aid to online information retrieval

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    Selection of search terms in an online search environment can be facilitated by the visual display of a knowledge map showing the various concepts and their links. This paper reports on a preliminary research aimed at designing a prototype knowledge map using DDC and its visual display. The prototype knowledge map created using the Protæ#169;gæ#169; and TGViz freeware has been demonstrated, and further areas of research in this field are discussed

    Ion-liquid based super-capacitors with inner gate diode-like separators

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    We demonstrate that the capacitance of ionic-liquid filled supercapacitors is substantially increased by placing a diode-like structure on the separator membrane. We call the structured separator: gate, and demonstrate that the order of a p-n layout with respect to the auxiliary electrode affects the overall cell's capacitance. The smallest ESR and the largest capacitance values are noted when the p-side is facing the auxiliary electrode.Comment: 11 pages, 8 figure

    All the Groups of Signal Analysis from the (1+1)-affine Galilei Group

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    We study the relationship between the (1+1)-affine Galilei group and four groups of interest in signal analysis and image processing, viz., the wavelet or the affine group of the line, the Weyl-Heisenberg, the shearlet and the Stockwell groups. We show how all these groups can be obtained either directly as subgroups, or as subgroups of central extensions of the affine Galilei group. We also study this at the level of unitary representations of the groups on Hilbert spaces.Comment: 28 pages, 1 figur

    A comprehensive study of the usability of multiple graphical passwords

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    Recognition-based graphical authentication systems (RBGSs) using images as passwords have been proposed as one potential solution to the need for more usable authentication. The rapid increase in the technologies requiring user authentication has increased the number of passwords that users have to remember. But nearly all prior work with RBGSs has studied the usability of a single password. In this paper, we present the first published comparison of the usability of multiple graphical passwords with four different image types: Mikon, doodle, art and everyday objects (food, buildings, sports etc.). A longi-tudinal experiment was performed with 100 participants over a period of 8 weeks, to examine the usability performance of each of the image types. The re-sults of the study demonstrate that object images are most usable in the sense of being more memorable and less time-consuming to employ, Mikon images are close behind but doodle and art images are significantly inferior. The results of our study complement cognitive literature on the picture superiority effect, vis-ual search process and nameability of visually complex images

    Nonlocal continuous variable correlations and violation of Bell's inequality for light beams with topological singularities

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    We consider optical beams with topological singularities which possess Schmidt decomposition and show that such classical beams share many features of two mode entanglement in quantum optics. We demonstrate the coherence properties of such beams through the violations of Bell inequality for continuous variables using the Wigner function. This violation is a consequence of correlations between the (x,px)(x, p_x) and (y,py)(y, p_y) spaces which mathematically play the same role as nonlocality in quantum mechanics. The Bell violation for the LG beams is shown to increase with higher orbital angular momenta ll of the vortex beam. This increase is reminiscent of enhancement of nonlocality for many particle Greenberger-Horne-Zeilinger states or for higher spins. The states with large ll can be easily produced using spatial light modulators.Comment: 6 pages and 2 figure
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