6,629 research outputs found

    Physics of a microsystem starting from non-equilibrium quantum statistical mechanics

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    In this paper we address the problem to give a concrete support to the idea, originally stemming from Niels Bohr, that quantum mechanics must be rooted inside the physics of macroscopic systems. It is shown that, starting from the formalism of the non-equilibrium statistical operator, which is now a consolidated part of quantum statistical mechanics, particular correlations between two isolated systems can be singled out and interpreted as microsystems. In this way also a new framework is established in which questions of decoherence can be naturally addressed.Comment: 14 pages, latex, no figures, contribution to the Proceedings of the XXXIII Symposium on Mathematical Physics (Torun, Poland

    Description of isolated macroscopic systems inside quantum mechanics

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    For an isolated macrosystem classical state parameters ζ(t)\zeta(t) are introduced inside a quantum mechanical treatment. By a suitable mathematical representation of the actual preparation procedure in the time interval [T,t0][T,t_0] a statistical operator is constructed as a solution of the Liouville von Neumann equation, exhibiting at time tt the state parameters ζ(t′)\zeta(t'), t0≤t′≤tt_0\leq t' \leq t, and {\it preparation parameters} related to times T≤t′≤t0T \leq t'\leq t_0. Relation with Zubarev's non-equilibrium statistical operator is discussed. A mechanism for memory loss is investigated and time evolution by a semigroup is obtained for a restricted set of relevant observables, slowly varying on a suitable time scale.Comment: 13 pages, latex, romp31 style, no figures, to appear in the Proceedings of the XXXI Symposium on Mathematical Physics (Torun, Poland), to be published in Rep. Math. Phy

    Learning to Detect Violent Videos using Convolutional Long Short-Term Memory

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    Developing a technique for the automatic analysis of surveillance videos in order to identify the presence of violence is of broad interest. In this work, we propose a deep neural network for the purpose of recognizing violent videos. A convolutional neural network is used to extract frame level features from a video. The frame level features are then aggregated using a variant of the long short term memory that uses convolutional gates. The convolutional neural network along with the convolutional long short term memory is capable of capturing localized spatio-temporal features which enables the analysis of local motion taking place in the video. We also propose to use adjacent frame differences as the input to the model thereby forcing it to encode the changes occurring in the video. The performance of the proposed feature extraction pipeline is evaluated on three standard benchmark datasets in terms of recognition accuracy. Comparison of the results obtained with the state of the art techniques revealed the promising capability of the proposed method in recognizing violent videos.Comment: Accepted in International Conference on Advanced Video and Signal based Surveillance(AVSS 2017

    Time scales in quantum mechanics by a scattering map

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    Inside quantum mechanics the problem of decoherence for an isolated, finite system is linked to a coarse-grained description of its dynamics.Comment: 10 pages, latex, no figure

    Maybe Definitely – Definitely Maybe? EC Competition Law – Is the Time Ripe for Reform?

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    [Summary]. The aim of this article is to discuss whether the timing for the Commission’s Proposal for reforming the implementation of Articles 81 and 82 of the EC Treaty is appropriate based on legal certainty considerations. The Proposal suggests to decentralise the day-to-day application of the EC antitrust rules further than is the case today and to abolish the present notification system whereby undertakings can apply for exemptions pursuant to Article 81(3) and negative clearances. The article provides examples showing that presently, the answers to certain legal questions of EC competition rules are vague or contradictory, and that if the proposed reform were to be implemented in its present form, the undertakings would have to carry the full risk for compliance with the competition rules but without a simple or straightforward way of obtaining guidance or legally binding exemptions or negative clearances. While recognising the need for a reform of the implementation system of the EC competition rules, the article argues that consistency and coherence in the understanding and application of the competition rules are a prerequisite to ensure legal certainty which, in turn, is a prerequisite for the implementation of the Commission’s plans to decentralise EC competition law application. It is therefore suggested that the time is not yet ripe for the type of reform proposed by the Commission and that efforts should instead focus on creating the basis for such a reform by adopting clear guidelines and/or binding legislation that secure the legal certainty of the undertakings that have to operate under the EC competition law framework

    Subdynamics through Time Scales and Scattering Maps in Quantum Field Theory

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    It is argued that the dynamics of an isolated system, due to the concrete procedure by which it is separated from the environment, has a non-Hamiltonian contribution. By a unified quantum field theoretical treatment of typical subdynamics, e.g., hydrodynamics, kinetic theory, master equation for a particle interacting with matter, we look for the structure of this more general dynamics.Comment: 16 pages, latex, no figures, to appear in the Proceedings of the Third International Conference on Quantum Communication & Measurement 1996 (Hakone, Japan
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