2,094 research outputs found

    A Regulatory Model for Context-Aware Abstract Framework

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    Proceedings of: 23rd International Conference on Industrial Engineering and Other Applications of Applied Intelligent Systems, IEA/AIE 2010, Cordoba, Spain, June 1-4, 2010.This paper presents a general framework to define a context aware application and analyzes social guarantees to be considered to develop this kind of applications following legal assumptions as privacy, human rights, etc. We present a review of legal issues in biometric user identification where several legal aspects have been developed in European Union regulation and a general framework to define context aware applications. As main result, paper presents a legal framework to be taken into account in any context-based application to ensure a harmonious and coherent system for the protection of fundamental rights.This work was supported in part by Projects CICYT TIN2008-06742-C02-02/TSI, CICYT TEC2008-06732-C02-02/TEC, CAM CONTEXTS (S2009/TIC-1485) and DPS2008-07029- C02-02.Publicad

    Shot noise in resonant tunneling through a zero-dimensional state with a complex energy spectrum

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    We investigate the noise properties of a GaAs/AlGaAs resonant tunneling structure at bias voltages where the current characteristic is determined by single electron tunneling. We discuss the suppression of the shot noise in the framework of a coupled two-state system. For large bias voltages we observed super-Poissonian shot noise up to values of the Fano factor α10\alpha \approx 10.Comment: 4 pages, 4 figures, accepted for Phys. Rev.

    On the ground state energy scaling in quasi-rung-dimerized spin ladders

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    On the basis of periodic boundary conditions we study perturbatively a large N asymptotics (N is the number of rungs) for the ground state energy density and gas parameter of a spin ladder with slightly destroyed rung-dimerization. Exactly rung-dimerized spin ladder is treated as the reference model. Explicit perturbative formulas are obtained for three special classes of spin ladders.Comment: 4 page

    Sialic acids on B cells are crucial for their survival and provide protection against apoptosis.

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    Sialic acids (Sias) on the B cell membrane are involved in cell migration, in the control of the complement system and, as sialic acid-binding immunoglobulin-like lectin (Siglec) ligands, in the regulation of cellular signaling. We studied the role of sialoglycans on B cells in a mouse model with B cell-specific deletion of cytidine monophosphate sialic acid synthase (CMAS), the enzyme essential for the synthesis of sialoglycans. Surprisingly, these mice showed a severe B cell deficiency in secondary lymphoid organs. Additional depletion of the complement factor C3 rescued the phenotype only marginally, demonstrating a complement-independent mechanism. The B cell survival receptor BAFF receptor was not up-regulated, and levels of activated caspase 3 and processed caspase 8 were high in B cells of Cmas-deficient mice, indicating ongoing apoptosis. Overexpressed Bcl-2 could not rescue this phenotype, pointing to extrinsic apoptosis. These results show that sialoglycans on the B cell surface are crucial for B cell survival by counteracting several death-inducing pathways

    A Planarity Test via Construction Sequences

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    Optimal linear-time algorithms for testing the planarity of a graph are well-known for over 35 years. However, these algorithms are quite involved and recent publications still try to give simpler linear-time tests. We give a simple reduction from planarity testing to the problem of computing a certain construction of a 3-connected graph. The approach is different from previous planarity tests; as key concept, we maintain a planar embedding that is 3-connected at each point in time. The algorithm runs in linear time and computes a planar embedding if the input graph is planar and a Kuratowski-subdivision otherwise

    Perturbation theories for the S=1/2 spin ladder with four-spin ring exchange

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    The isotropic S=1/2 antiferromagnetic spin ladder with additional four-spin ring exchange is studied perturbatively in the strong coupling regime with the help of cluster expansion technique, and by means of bosonization in the weak coupling limit. It is found that a sufficiently large strength of ring exchange leads to a second-order phase transition, and the shape of the boundary in the vicinity of the known exact transition point is obtained. The critical exponent for the gap is found to be η1\eta\simeq1, in agreement both with exact results available for the dimer line and with the bosonization analysis. The phase emerging for high values of the ring exchange is argued to be gapped and spontaneously dimerized. The results for the transition line from strong coupling and from weak coupling match with each other naturally.Comment: 8 pages, 4 figures, some minor changes in text and reference

    Fe and N self-diffusion in amorphous FeN: A SIMS and neutron reflectivity study

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    Simultaneous measurement of self-diffusion of iron and nitrogen in amorphous iron nitride (Fe86N14) using secondary ion mass spectroscopy (SIMS) technique has been done. In addition neutron reflectivity (NR) technique was employed to study the Fe diffusion in the same compound. The broadening of a tracer layer of 57Fe8615N14 sandwiched between Fe86N14 layers was observed after isothermal vacuum annealing of the films at different temperatures in SIMS measurements. And a decay of the Bragg peak intensity after isothermal annealing was observed in [Fe86N14/57Fe86N14]10 multilayers in NR. Strong structural relaxation of diffusion coefficient was observed below the crystallization temperature of the amorphous phase in both measurements. It was observed from the SIMS measurements that Fe diffusion was about 2 orders of magnitude smaller compared to nitrogen at a given temperature. The NR measurements reveal that the mechanism of Fe self-diffusion is very similar to that in metal-metal type metallic glasses. The structural relaxation time for Fe and N diffusion was found comparable indicating that the obtained relaxation time essentially pertain to the structural relaxation of the amorphous phase.Comment: 10 pages 12 figure

    Phase Coherence and Control of Stored Photonic Information

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    We report the demonstration of phase coherence and control for the recently developed "light storage" technique. Specifically, we use a pulsed magnetic field to vary the phase of atomic spin excitations which result from the deceleration and storing of a light pulse in warm Rb vapor. We then convert the spin excitations back into light and detect the resultant phase shift in an optical interferometric measurement. The coherent storage of photon states in matter is essential for the practical realization of many basic concepts in quantum information processing.Comment: 5 pages, 3 figures. Submitted to Phys. Rev. Let

    Regulatory Model for AAL

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    Proceedings of: 6th International Conference on Soft Computing Models in Industrial and Environmental Applications (SOCO 2011). Salamanca, April 6-8, 2011Abstract: In this work, authors define a set of principles that should be contained in context-aware applications (including biometric sensors) to accomplish the legal aspect in Europe and USA. Paper presents the necessity to consider legal aspect, related with pri-vacy or human rights, into the development of the incipient context based services. Clearly, context based services and Ambient Intelligence (and the most promising work area in Europe that is Ambient Assisted Living, ALL) needs a great effort in research new identification procedures.Publicad
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