Search results for "REEs"

showing 10 items of 921 documents

Variable Length Memory Chains: Characterization of stationary probability measures

2021

Variable Length Memory Chains (VLMC), which are generalizations of finite order Markov chains, turn out to be an essential tool to modelize random sequences in many domains, as well as an interesting object in contemporary probability theory. The question of the existence of stationary probability measures leads us to introduce a key combinatorial structure for words produced by a VLMC: the Longest Internal Suffix. This notion allows us to state a necessary and sufficient condition for a general VLMC to admit a unique invariant probability measure. This condition turns out to get a much simpler form for a subclass of VLMC: the stable VLMC. This natural subclass, unlike the general case, enj…

Statistics and ProbabilityPure mathematicsLongest Internal SuffixStationary distributionMarkov chain60J05 60C05 60G10Probability (math.PR)010102 general mathematics01 natural sciencesMeasure (mathematics)Variable Length Memory Chains010104 statistics & probabilityProbability theoryConvergence of random variablesFOS: MathematicsCountable setState spaceRenewal theory[MATH]Mathematics [math]0101 mathematicsstable context treessemi-Markov chainsMathematics - Probabilitystationary probability measureMathematicsBernoulli
researchProduct

On statistical inference for the random set generated Cox process with set-marking.

2007

Cox point process is a process class for hierarchical modelling of systems of non-interacting points in ℝd under environmental heterogeneity which is modelled through a random intensity function. In this work a class of Cox processes is suggested where the random intensity is generated by a random closed set. Such heterogeneity appears for example in forestry where silvicultural treatments like harvesting and site-preparation create geometrical patterns for tree density variation in two different phases. In this paper the second order property, important both in data analysis and in the context of spatial sampling, is derived. The usefulness of the random set generated Cox process is highly…

Statistics and ProbabilityRandom graphRandom fieldMultivariate random variableRandom functionRandom elementGeneral MedicineModels BiologicalPoint processTreesCox processRandom variateStatisticsComputer SimulationStatistics Probability and UncertaintyAlgorithmMathematicsProportional Hazards ModelsBiometrical journal. Biometrische Zeitschrift
researchProduct

MODERATE DEVIATION PRINCIPLES FOR BIFURCATING MARKOV CHAINS: CASE OF FUNCTIONS DEPENDENT OF ONE VARIABLE

2021

The main purpose of this article is to establish moderate deviation principles for additive functionals of bifurcating Markov chains. Bifurcating Markov chains are a class of processes which are indexed by a regular binary tree. They can be seen as the models which represent the evolution of a trait along a population where each individual has two offsprings. Unlike the previous results of Bitseki, Djellout \& Guillin (2014), we consider here the case of functions which depend only on one variable. So, mainly inspired by the recent works of Bitseki \& Delmas (2020) about the central limit theorem for general additive functionals of bifurcating Markov chains, we give here a moderate deviatio…

Statistics and Probability[MATH.MATH-PR]Mathematics [math]/Probability [math.PR][MATH.MATH-PR] Mathematics [math]/Probability [math.PR]60J80Bifurcating Markov chainsbinary trees[MATH]Mathematics [math]binary trees Mathematics Subject Classification (2020): 60F10deviation inequalitiesMathematics - Probabilitymoderate deviation principles
researchProduct

Contributed discussion on article by Pratola

2016

The author should be commended for his outstanding contribution to the literature on Bayesian regression tree models. The author introduces three innovative sampling approaches which allow for efficient traversal of the model space. In this response, we add a fourth alternative.

Statistics and Probabilitymodel selectionMarkov Chain Monte Carlo (MCMC)Bayesian regression treeComputer scienceBig dataBayesian regression tree (BRT) modelsComputingMilieux_LEGALASPECTSOFCOMPUTINGbirth–death processMachine learningcomputer.software_genreSequential Monte Carlo methods01 natural sciencespopulation Markov chain Monte Carlo010104 statistics & probabilitysymbols.namesakebig data0502 economics and businessBayesian Regression Trees (BART)0101 mathematics050205 econometrics Bayesian treed regressionMultiple Try Metropolis algorithmsINFERÊNCIA ESTATÍSTICAbusiness.industryApplied MathematicsModel selection05 social sciencesRejection samplingData scienceVariable-order Bayesian networkTree (data structure)Tree traversalMarkov chain Monte Carlocontinuous time Markov processsymbolsArtificial intelligencebusinessBayesian linear regressioncommunication-freecomputerGibbs samplingBayesian Analysis
researchProduct

Stochastic seismic analysis of multidegree of freedom systems

1984

Abstract A unconditionally stable step-by-step procedure is proposed to evaluate the mean square response of a linear system with several degrees of freedom, subjected to earthquake ground motion. A non-stationary modulated random process, obtained as the product of a deterministic time envelope function and a stationary noise, is used to simulate earthquake acceleration. The accuracy of the procedure and its extension to nonlinear systems are discussed. Numerical examples are given for a hysteretic system, a duffing oscillator and a linear system with several degrees of freedom.

Stochastic processMathematical analysisLinear systemDegrees of freedom (statistics)stochastic analysisDuffing equationAcceleration (differential geometry)earthquakes; probability theory; stochastic analysisSeismic analysisNonlinear systemEarthquake simulationControl theoryprobability theoryearthquakesCivil and Structural EngineeringMathematics
researchProduct

Diurnal Regulation of Leaf Water Status in High- and Low-Mannitol Olive Cultivars

2014

The role of mannitol and malic acid in the regulation of diurnal leaf water relations was investigated in ‘Biancolilla’ (high-mannitol) and ‘Cerasuola’ (low-mannitol) olive trees. Photosynthetic photon flux density (PPFD), vapor pressure deficit (VPD), stomatal conductance (gs), transpiration rate (T), relative water content (RWC), mannitol and malic acid were measured in ‘Biancolilla’ and ‘Cerasuola’ leaves during a dry and hot day of summer in Sicily. In general, leaves of ‘Biancolilla’ trees exhibited greater mannitol content, higher gs and T, but lower RWC than leaves of ‘Cerasuola’ trees. Differences in gs and T between the two cultivars were evident mainly in mid to late morning. ‘Bia…

Stomatal conductancemalate; polyol; relative water content; stomatal conductance; transpiration; vapor pressure deficitVapour Pressure DeficitPlant ScienceArticletranspirationchemistry.chemical_compoundmedicineCultivarWater contentEcology Evolution Behavior and SystematicsTranspirationmalateEcologyrelative water contentvapor pressure deficitBotanyOlive treesSettore AGR/03 - Arboricoltura Generale E Coltivazioni ArboreeHorticulturechemistrystomatal conductanceQK1-989polyolMannitolMalic acidmedicine.drugPlants; Volume 3; Issue 2; Pages: 196-208
researchProduct

An Approximate Technique for Dynamic Elastic-Plastic Analysis

1994

The possibility of obtaining an approximate sufficiently reliable response for elasticplastic discretized structures subjected to dynamic load (kinematical and/or mechanical), with alow computational effort, has been considered. A suitable technique to this effect comes from the form of the dynamic influence matrix of imposed plastic strains on self-stresses, which is shaped by adding up a sparse time-dependent matrix and a block diagonal time-independent matrix (which is the sum of two block diagonal matrices). Several cases of practical interest have been studied, among these cases a special one where all the degrees-of-freedom are dynamic. The technique is compared to other approximate t…

Stress (mechanics)VibrationMechanics of MaterialsMechanical EngineeringNumerical analysisDegrees of freedomMathematical analysisGeometryQuadratic programmingCondensed Matter PhysicsMathematicsElastic plasticJournal of Applied Mechanics
researchProduct

Detecting topology through dynamics in interacting fermionic wires

2020

We describe a protocol to read out the topological invariant of interacting 1D chiral models, based on measuring the mean chiral displacement of time-evolving bulk excitations. We present analytical calculations and numerical Matrix Product State simulations of interacting Su-Schrieffer-Heeger (SSH) chains, demonstrating how the mean chiral displacement allows to distinguish between topological insulator, trivial insulator and symmetry-broken phases. Finally, we provide an experimental blueprint for realizing a model displaying these three phases and describe how to detect those.

Strongly Correlated Electrons (cond-mat.str-el)business.industrymedia_common.quotation_subjectLibrary scienceFOS: Physical sciencesTopologyTopologiaCondensed Matter - Strongly Correlated ElectronsHospitalityDynamics (music)ExcellenceQuantum Gases (cond-mat.quant-gas):Física::Física de fluids::Física de gasos [Àrees temàtiques de la UPC]Center (algebra and category theory)ddc:530SociologyGasesFermionic wiresCondensed Matter - Quantum Gasesbusinessmedia_common
researchProduct

Revista electrónica de investigación y evaluación educativa

2010

Este trabajo tiene el propósito de mostrar el uso de la metodología de Modelos de Ecuaciones Estructurales (SEM) para validar la estructura conceptual de cuestionarios de contexto que se utilizan en los estudios nacionales e internacionales para evaluar el logro educativo de los escolares. Desgraciadamente, los organismos evaluadores no destinan los mismos recursos técnicos a los cuestionarios de contexto que a las pruebas de aprendizaje, por lo que rara vez los primeros son sujetos a estudios de validez. Para mostrar el uso de la metodología SEM, se seleccionó el cuestionario dirigido a alumnos que utilizó el Instituto Nacional para la Evaluación de la Educación (INEE) para conocer los fac…

Structural Equations Modeling Confirmatory Factor Analysis Construct Validity Context Questionnaires National Institute for the Evaluation of Educationevaluación formativaaprendizajeeducación preescolarcuestionario
researchProduct

Skyrmion formation due to unconventional magnetic modes in anisotropic multiband superconductors

2018

Multiband superconductors have a sufficient number of degrees of freedom to allow topological excitations characterized by Skyrmionic topological invariants. In the most common, clean s-wave multiband, systems the interband magnetic coupling favours composite vortex solutions, without a Skyrmionic topological charge. It was discussed recently that certain kinds of anisotropies lead to hybridisation of the interband phase difference (Leggett) mode with magnetic modes, dramatically changing the hydromagnetostatics of the system. Here we report this effect for a range of parameters that substantially alter the nature of the topological excitations, leading to solutions characterized by a nontr…

SuperconductivityPhysicsta114SkyrmionCondensed Matter - SuperconductivitysuperconductivityDegrees of freedommultiband superconductivityFOS: Physical sciencesvortices in superconductors02 engineering and technology021001 nanoscience & nanotechnology01 natural sciencessuprajohteetSuperconductivity (cond-mat.supr-con)Theoretical physicsCondensed Matter::Superconductivity0103 physical sciencesTopological invariants010306 general physics0210 nano-technologyAnisotropyPhysical Review B
researchProduct