10,781 research outputs found

    Identification of Hidden Failures in Process Control Systems Based on the HMG Method

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    We will continue here the research work, the goal of which was to introduce the notion of nondeterministic aggregation operators and study their properties, even in relation to classification systems and the associated learning problem. Here we will concentrate mostly on the notion of the nondeterministic aggregation system and its relation with deterministic ones. We will also see how such a model extends a discretized version of a model of participatory learning with an arousal background mechanism

    Dynamics and stability of radiation-driven double ablation front structures.

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    The dynamics of double ablation front (DAF) structures is studied for planar targets with moderate atomic number ablators. These structures are obtained in hydrodynamic simulations for various materials and laser intensities and are qualitatively characterized during the acceleration stage of the target. The importance of the radiative transport for the DAF dynamics is then demonstrated. Simulated hydrodynamic profiles are compared with a theoretical model, showing the consistency of the model and the relevant parameters for the dynamics description. The stability of DAF structures with respect to two-dimensional perturbations is studied using two different approaches: one considers the assumptions of the theoretical model and the other one a more complete physics. The numerical simulations performed with both approaches demonstrate good agreement of dispersion curve

    Regional Economic Policies: Four Country Cases

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    This paper presents four case studies of economies with well-developed regional policies.These include the European Union, Spain, Italy and Brazil. These cases have been chosen because of their relevance when studying regional problems in Colombia. In all of the cases regional policy has had a relatively poor perfomance, since regional disparities have not been significantly reduced. However, one could argue that disparities would have been larger without these policy iniciatives. Thus, the results highlight the difficulties in devoloping a successful regional policy.

    Quark and gluon spin-2 form factors to two-loops in QCD

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    We present complete two-loop radiative corrections to the graviton-quark-antiquark form factor G^* \rightarrow q \overline q and graviton-gluon-gluon form factor G^* \rightarrow g g in SU(N) gauge theory with n_f light flavours using d-dimensional regularisation to all orders in \varepsilon=d-4. This is an important ingredient to next-to-next-to-leading order QCD corrections to hadronic scattering processes in models with large extra-dimensions where Kaluza-Klein graviton modes couple to Standard Model fields. We show that these form factors obey Sudakov integro-differential equation and the resulting cusp, collinear and soft anomalous dimensions coincide with those of electroweak vector boson and gluon form factors. We also find the universal behaviour of the infrared singularities in accordance with the proposal by Catani.Comment: 14 pages, LaTeX; references added, version to appear in JHE
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