4,469 research outputs found

    Reducing Clocks in Timed Automata while Preserving Bisimulation

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    Model checking timed automata becomes increasingly complex with the increase in the number of clocks. Hence it is desirable that one constructs an automaton with the minimum number of clocks possible. The problem of checking whether there exists a timed automaton with a smaller number of clocks such that the timed language accepted by the original automaton is preserved is known to be undecidable. In this paper, we give a construction, which for any given timed automaton produces a timed bisimilar automaton with the least number of clocks. Further, we show that such an automaton with the minimum possible number of clocks can be constructed in time that is doubly exponential in the number of clocks of the original automaton.Comment: 28 pages including reference, 8 figures, full version of paper accepted in CONCUR 201

    Evidence for two spin-glass transitions with magnetoelastic and magnetoelectric couplings in the multiferroic (Bi1βˆ’x_{1-x}Bax_x)(Fe1βˆ’x_{1-x}Tix_x)O3_3 system

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    For disordered Heisenberg systems with small single ion anisotropy, two spin glass transitions below the long range ordered phase transition temperature has been predicted theoretically for compositions close to the percolation threshold. Experimental verification of these predictions is still controversial for conventional spin glasses. We show that multiferroic spin glass systems can provide a unique platform for verifying these theoretical predictions via a study of change in magnetoelastic and magnetoelectric couplings, obtained from an analysis of diffraction data, at the spin glass transition temperatures. Results of macroscopic and microscopic (x-ray and neutron scattering) measurements are presented on disordered BiFeO3, a canonical Heisenberg system with small single ion anisotropy, which reveal appearance of two spin glass phases SG1 and SG2 in coexistence with the LRO phase below the A-T and G-T lines. It is shown that the temperature dependence of the integrated intensity of the antiferromagnetic peak shows dips with respect to the Brillouin function behaviour around the SG1 and SG2 transition temperatures. The ferroelectric polarisation changes significantly at the two spin glass transition temperatures. These results, obtained using microscopic techniques, clearly demonstrate that the SG1 and SG2 transitions occur on the same magnetic sublattice and are intrinsic to the system. We also construct a phase diagram showing all the magnetic phases in BF-xBT system. While our results on the two spin glass transitions support the theoretical predictions, it also raises several open questions which need to be addressed by revisiting the existing theories of spin glass transitions by taking into account the effect of magnetoelastic and magnetoelectric couplings as well as electromagnons.Comment: 59 pages 21 figure

    DUPLICATION OF THUMB AT META CARPO PHALANGEAL JOINT IN RIGHT HAND OF 19 YEARS OLD BOY -A CASE REPORT

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    Here reporting a case of bifurcation of right thumb in the form of beak like deformity on the right side in a 19 years old young male present since birth. This anomaly was coming in the way his normal activities like lifting heavy objects and while performing any purposeful movements like writing and while taking his bolus of food. There was definitely family history of different anomalies, but no history of systemic diseases running in the family. There was no other anomaly in him. Other fingers and toes were absolutely normal. Though this is common anomaly that is found in the society, it has profound developmental and Anthropological importance. Hence studied and reported

    A Unifying Approach to Decide Relations for Timed Automata and their Game Characterization

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    In this paper we present a unifying approach for deciding various bisimulations, simulation equivalences and preorders between two timed automata states. We propose a zone based method for deciding these relations in which we eliminate an explicit product construction of the region graphs or the zone graphs as in the classical methods. Our method is also generic and can be used to decide several timed relations. We also present a game characterization for these timed relations and show that the game hierarchy reflects the hierarchy of the timed relations. One can obtain an infinite game hierarchy and thus the game characterization further indicates the possibility of defining new timed relations which have not been studied yet. The game characterization also helps us to come up with a formula which encodes the separation between two states that are not timed bisimilar. Such distinguishing formulae can also be generated for many relations other than timed bisimilarity.Comment: In Proceedings EXPRESS/SOS 2013, arXiv:1307.690

    Framework on Retrieval of Hypermedia Data using Data mining Technique

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    Image Annotation is a method to reveal the meaning for a specific image .The embedded meaning in the image is identified and mined. The Scenario is identified through the image annotation scheme with in a provided training. The focus is on the blur images, noisy images and images with pixels lost. The image annotation can be done on the good resolution image. The analysis carried outon the image data to derive the information and image restoration takes place. Image mining deals with extracting embedded details, patterns and their relationship in images. Embedded details in the image could be extracted using high-level features that are robust. Inpainting techniques can be utilized for cleaning the image .The analytics is applied on enormous amount of data, techniques performed on the test images sets for better accuracy
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