Search results for "probability"

showing 10 items of 3417 documents

A generalization of the Binomial distribution based on the dependence ratio

2015

We propose a generalization of the Binomial distribution, called DR-Binomial, which accommodates dependence among units through a model based on the dependence ratio (Ekholm et al., Biometrika, 82, 1995, 847). Properties of the DR-Binomial are discussed, and the constraints on its parameter space are studied in detail. Likelihood-based inference is presented, using both the joint and profile likelihoods; the usefulness of the DR-Binomial in applications is illustrated on a real dataset displaying negative unit-dependence, and hence under-dispersion compared with the Binomial. Although the DR-Binomial turns out to be a reparameterization of Altham's Additive-Binomial and Kupper-Haseman's Cor…

Statistics and ProbabilityDependent binary dataGeneralized Binomial distributionSettore SECS-S/01 - StatisticaDependence ratio
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Second-order diagnostics for space-time point processes with application to seismic events

2008

A diagnostic method for space-time point process is introduced and used to interpret and assess the goodness of fit of particular models to real data such as the seismic ones. The proposed method is founded on the definition of a weighted process and allows to detect second-order features of data, like long-range dependence and fractal behavior, that are not accounted for by the fitted model. Applications to earthquake data are provided. Copyright © 2008 John Wiley & Sons, Ltd.

Statistics and ProbabilityDiagnostic methodsComputer scienceEcological ModelingSpace timeProcess (computing)ResidualPoint processFractalGoodness of fitOrder (business)EconometricsSettore SECS-S/01 - StatisticaAlgorithmPoint processes residual analysis second-order features ETAS model seismic processEnvironmetrics
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Attractors for non-autonomous retarded lattice dynamical systems

2015

AbstractIn this paperwe study a non-autonomous lattice dynamical system with delay. Under rather general growth and dissipative conditions on the nonlinear term,we define a non-autonomous dynamical system and prove the existence of a pullback attractor for such system as well. Both multivalued and single-valued cases are considered.

Statistics and ProbabilityDifferential equations with delayDynamical systems theoryNon-autonomous systemslattice dynamical systemsPullback attractorHamiltonian systemLinear dynamical systemProjected dynamical systemAttractorQA1-939pullback attractorMathematicsNumerical AnalysisApplied MathematicsMathematical analysisdifferential equations with delaynon-autonomous systemsClassical mechanicsLattice dynamical systemsPullback attractorset-valued dynamical systemsSet-valued dynamical systemsLimit setRandom dynamical systemMathematicsAnalysis
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Hores: A timetabling system for Spanish secondary schools

1995

Constructing a timetable is a difficult problem faced by every school every year. A feasible solution has to satisfy many different requirements and constraints. A good solution has to provide compact timetables for classes and teachers. In order to help the schools, we have developed HORES, a robust and flexible timetabling system suited to the needs of Spanish secondary schools. HORES runs on a PC and is fast and user-friendly. It may handle virtually every condition required by the schools and obtains good quality solutions in very short computing times. It also allows the user to modify interactively the solutions. HORES is now being used by schools with satisfactory results.

Statistics and ProbabilityDifficult problemMathematical optimizationInformation Systems and ManagementOperations researchComputer sciencemedia_common.quotation_subjectManagement Science and Operations ResearchTabu searchOrder (business)Modeling and SimulationDiscrete Mathematics and CombinatoricsQuality (business)media_commonTop
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New approach to numerical computation of the eigenfunctions of the continuous spectrum of three-particle Schrödinger operator: I. One-dimensional par…

2009

Basing on analogy between the three-body scattering problem and the diffraction problem of the plane wave (for the case of the short range pair potentials) by the system of six half transparent screens, we presented a new approach to the few-body scattering problem. The numerical results have been obtained for the case of the short range nonnegative pair potentials. The presented method allows a natural generalization to the case of the long range pair potentials.

Statistics and ProbabilityDiffractionGeneralizationScattering34L25 81U08ComputationOperator (physics)Continuous spectrumMathematical analysisPlane waveGeneral Physics and AstronomyStatistical and Nonlinear PhysicsGeometryEigenfunctionModeling and SimulationMathematical PhysicsMathematicsJournal of Physics A: Mathematical and Theoretical
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Microstructural sensitivity of local porosity distributions

1992

The recently introduced concept of local porosity distributions for the geometric characterization of arbitrary porous media is scrutinized using computer generated pore space images. The paper presents the first direct determination of local porosity distributions from digital images. Pore space images with identical two point correlation functions are employed to analyse the geometrical sensitivity of the local porosity concept. The main finding is that local distributions can be used to discriminate between images which are indistinguishable using standard correlation functions. We also discuss the question of length scales associated with the local porosity concept.

Statistics and ProbabilityDigital imageGeometryCharacterisation of pore space in soilSensitivity (control systems)Condensed Matter PhysicsPorosityPorous mediumPhysics::GeophysicsCharacterization (materials science)MathematicsPoint correlationPhysica A: Statistical Mechanics and its Applications
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Erosion–dilation analysis for experimental and synthetic microstructures of sedimentary rock

2000

Abstract Microstructures such as rock samples or simulated structures can be described and characterized by means of ideas of spatial statistics and mathematical morphology. A powerful approach is to transform a given 3D structure by operations of mathematical morphology such as dilation and erosion. This leads to families of structures, for which various characteristics can be determined, for example, porosity, specific connectivity number or correlation and connectivity functions. An application of this idea leads to a clear discrimination between a sample of Fontainebleau sandstone and two simulated samples.

Statistics and ProbabilityDilation (morphology)MineralogySedimentary rockMathematical morphologyCondensed Matter PhysicsMicrostructurePorositySpatial analysisGeologyPhysica A: Statistical Mechanics and its Applications
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Intensity estimation for inhomogeneous Gibbs point process with covariates-dependent chemical activity

2014

Recent development of intensity estimation for inhomogeneous spatial point processes with covariates suggests that kerneling in the covariate space is a competitive intensity estimation method for inhomogeneous Poisson processes. It is not known whether this advantageous performance is still valid when the points interact. In the simplest common case, this happens, for example, when the objects presented as points have a spatial dimension. In this paper, kerneling in the covariate space is extended to Gibbs processes with covariates-dependent chemical activity and inhibitive interactions, and the performance of the approach is studied through extensive simulation experiments. It is demonstr…

Statistics and ProbabilityDimensionality reductionNonparametric statisticsPoisson distributionPoint processsymbols.namesakeDimension (vector space)CovariatesymbolsEconometricsStatistics::MethodologyStatistical physicsStatistics Probability and UncertaintySmoothingMathematicsParametric statisticsStatistica Neerlandica
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Comparacion numerica de algoritmos para calcular distribuciones estacionarias de cadenas de Markov finitas

1992

En este trabajo se estudia la eficiencia de un conjunto de algoritmos, exactos e iterativos, para el problema de obtener la distribucion estacionaria de una cadena de Markov homogenea, irreducible y finita. Se presentan los resultados computacionales obtenidos al resolver problemas de diferentes tipos y tamanos, aleatoriamente generados, asi como el tratamiento estadistico realizado sobre los mismos. Se ha comparado la estabilidad de estos algoritmos frente a la perdida de irreducibilidad y la existencia de estados transitorios mediante su aplicacion a 26 problemas test. El trabajo concluye con una discusion del comportamiento de los diversos algoritmos.

Statistics and ProbabilityDiscrete Mathematics and CombinatoricsGeneral ChemistryCatalysisTrabajos de Investigacion Operativa
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Estudio bayesiano de los periodos de ocupacion y desocupacion en una cola M/M/1/∞/FIFO en equilibrio

1986

En este articulo, para un modelo de colas M/M/1/8/FIFO en equilibrio, se obtiene la distribucion predictiva del tiempo de duracion de un periodo de ocupacion, y de desocupacion de la cola, asi como la distribucion predictiva final del numero de personas atendidas en un periodo de ocupacion, y la probabilidad de que este sea finito. Finalmente, dichos resultados se aplican en una linea de espera concreta.

Statistics and ProbabilityDiscrete Mathematics and CombinatoricsGeneral ChemistryCatalysisTrabajos de Investigacion Operativa
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