26 resultados para Minkowski sum
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The estimation of the number of people in an area under surveillance is very important for the problem of crowd monitoring. When an area reaches an occupation level greater than the projected one, people's safety can be in danger. This paper describes a new technique for crowd density estimation based on Minkowski fractal dimension. Fractal dimension has been widely used to characterize data texture in a large number of physical and biological sciences. The results of our experiments show that fractal dimension can also be used to characterize levels of people congestion in images of crowds. The proposed technique is compared with a statistical and a spectral technique, in a test study of nearly 300 images of a specific area of the Liverpool Street Railway Station, London, UK. Results obtained in this test study are presented.
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A measurement of the inclusive WW+WZ diboson production cross section in proton-proton collisions is reported, based on events containing a leptonically decaying W boson and exactly two jets. The data sample, collected at √s = 7 TeV with the CMS detector at the LHC, corresponds to an integrated luminosity of 5. 0 fb-1. The measured value of the sum of the inclusive WW and WZ cross sections is σ(pp→WW+WZ)=68. 9±8. 7 (stat.)±9. 7 (syst.)±1. 5 (lum.) pb, consistent with the standard model prediction of 65. 6±2. 2 pb. This is the first measurement of WW+WZ production in pp collisions using this signature. No evidence for anomalous triple gauge couplings is found and upper limits are set on their magnitudes. © 2013 CERN for the benefit of the CMS collaboration.
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In the study of the Type II superstring, it is useful to consider the BRST complex associated to the sum of two pure spinors. The cohomology of this complex is an infinite-dimensional vector space. It is also a finite-dimensional algebra over the algebra of functions of a single pure spinor. In this paper we study the multiplicative structure. © 2013 World Scientific Publishing Company.
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We use QCD sum rules to study the possible existence of a Θc(3250) charmed pentaquark. We consider the contributions of condensates up to dimension 12 and work at leading order in αs. We obtain mΘc=(3.29±0.13) GeV, compatible with the mass of the structure seen by BABAR Collaboration in the decay channel B-→p̄Σc++π-π-. The proposed state is compatible with a previous proposed pentaquark state in the anticharmed sector. © 2013 American Physical Society.
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Os estudos de Guerreiro Ramos sobre condição do negro no Brasil repõem a questão em novas bases, identificando seu núcleo no reflexo da patologia social do branco brasileiro e na própria atitude dos estudiosos que transformariam o negro-vida em tema. Ramos propõe então a assunção da negritude e a integração social por meio do adestramento cultural, ao que se contrapõe Costa Pinto, ao afirmar a preponderância do negro proletário. Entretanto, ambos pensadores foram relegados pelo racialismo do discurso dominante na atualidade.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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We set up sum rules for heavy lambda decays in a full QCD calculation which in the heavy quark mass limit incorporates the symmetries of heavy quark effective theory. For the semileptonic Λc decay we obtain a reasonable agreement with experiment. For the Λb semileptonic decay we find at the zero recoil point a violation of the heavy quark symmetry of about 20%. © 1998 Published by Elsevier Science B.V. All rights reserved.
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In this work we calculate the form factors of the Lambda(c) and Lambda(b) semileptonic decay using the QCD sum rules approach. We found that the form factors sum rules are more stable than the respective mass sum rules, and we get a decay rate for Lambda(c) compatible with experiment.
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QCD sum rules are used to calculate the contribution of the short-distance single-quark transition s-->d gamma to the amplitudes of the hyperon radiative decay Omega(-)-->Xi(-) gamma. We reevaluate the Wilson coefficient of the effective operator responsible for this transition. We obtain a branching ratio which is comparable to the unitarity limit.
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This paper proposes a technique for solving the multiobjective environmental/economic dispatch problem using the weighted sum and ε-constraint strategies, which transform the problem into a set of single-objective problems. In the first strategy, the objective function is a weighted sum of the environmental and economic objective functions. The second strategy considers one of the objective functions: in this case, the environmental function, as a problem constraint, bounded above by a constant. A specific predictor-corrector primal-dual interior point method which uses the modified log barrier is proposed for solving the set of single-objective problems generated by such strategies. The purpose of the modified barrier approach is to solve the problem with relaxation of its original feasible region, enabling the method to be initialized with unfeasible points. The tests involving the proposed solution technique indicate i) the efficiency of the proposed method with respect to the initialization with unfeasible points, and ii) its ability to find a set of efficient solutions for the multiobjective environmental/economic dispatch problem.