Search results for " Models"

showing 10 items of 4240 documents

Hybrid kernel estimates of space-time earthquake occurrence rates using the Etas model

2010

The following steps are suggested for smoothing the occurrence patterns in a clustered space–time process, in particular the data from an earthquake catalogue. First, the original data is fitted by a temporal version of the ETAS model, and the occurrence times are transformed by using the cumulative form of the fitted ETAS model. Then the transformed data (transformed times and original locations) is smoothed by a space–time kernel with bandwidth obtained by optimizing a naive likelihood cross-validation. Finally, the estimated intensity for the original data is obtained by back-transforming the estimated intensity for the transformed data. This technique is used to estimate the intensity f…

Bandwidths Parameters Cross-validation ETAS models Intensity function Kernel estimates Space-time point processes Space-time ETAS model Transformation of time.Settore SECS-S/01 - Statistica
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VECTOR-BARYON DYNAMICS IN γN → K0Σ REACTIONS

2014

A coupled channel model for the interaction of vector mesons with baryons is employed in the study of the γp → K0Σ+ reaction around the K*Λ and K*Σ thresholds, where the recent CBELSA/TAPS cross section shows a sudden drop and the differential cross section experiences a transition from a forward-peaked distribution to a flat one. A delicate interference between amplitudes having K*Λ and K*Σ intermediate states is found. The sharp downfall is dictated by the presence of a N* resonance produced by our model, a feature that we have employed to infer its properties. Predictions for the complementary γn → K0Σ0 reaction are also given.

BaryonScattering cross-sectionPhysicsAmplitudeMesonDrop (liquid)ResonanceAtomic physicsChannel modelsInternational Journal of Modern Physics: Conference Series
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Dynamic Gaussian Graphical Models for Modelling Genomic Networks

2014

After sequencing the entire DNA for various organisms, the challenge has become understanding the functional interrelatedness of the genome. Only by understanding the pathways for various complex diseases can we begin to make sense of any type of treatment. Unfortunately, decyphering the genomic network structure is an enormous task. Even with a small number of genes the number of possible networks is very large. This problem becomes even more difficult, when we consider dynamical networks. We consider the problem of estimating a sparse dynamic Gaussian graphical model with \(L_1\) penalized maximum likelihood of structured precision matrix. The structure can consist of specific time dynami…

Basis (linear algebra)Computational complexity theoryComputer scienceGaussianFatorial Gaussian graphical modelsPenalized graphical models; Fatorial Gaussian graphical modelsType (model theory)Constraint (information theory)Matrix (mathematics)symbols.namesakeConvex optimizationsymbolsGraphical modelPenalized graphical modelSettore SECS-S/01 - StatisticaAlgorithm
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Q-Chem 2.0: a high-performanceab initio electronic structure program package

2000

ABSTRACT: Q-Chem 2.0 is a new release of an electronic structure programpackage, capable of performing first principles calculations on the ground andexcited states of molecules using both density functional theory and wavefunction-based methods. A review of the technical features contained withinQ-Chem 2.0 is presented. This article contains brief descriptive discussions of thekey physical features of all new algorithms and theoretical models, together withsample calculations that illustrate their performance. c 2000 John Wiley S electronic structure; density functional theory;computer program; computational chemistry Introduction A reader glancing casually at this article mightsuspect on t…

Basis (linear algebra)Computer programProgramming languageComputer sciencePrincipal (computer security)Theoretical modelsAb initioGeneral ChemistryElectronic structurecomputer.software_genreComputational scienceComputational MathematicsKey (cryptography)Density functional theorycomputerJournal of Computational Chemistry
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Social Emotional Competence, Learning Outcomes, Emotional and Behavioral Difficulties of Preschool Children: Parent and Teacher Evaluations

2022

This paper addresses the role of social emotional competence in the emotional and behavioral problems and learning outcomes of preschool children based on their parents’ and teachers’ evaluations. In this study, we compared the perceptions of teachers and parents when evaluating the same child using the multi-informant assessment. First, the associations and differences between both the informant evaluations were investigated. Second, the correlation of the social emotional competence and emotional, and behavioral difficulties among preschool children was analyzed, separately addressing their parents’ and teachers’ evaluations. Third, the role of the preschool children’s social emotional co…

Behavior disorders in childrenpreschool childrenemotional and behavioral difficultieeducationMultilevel models (Statistics)learning outcomeChild psychologyBF1-990learning outcomessocioeconomic statusM-PSI/04 - PSICOLOGIA DELLO SVILUPPO E PSICOLOGIA DELL'EDUCAZIONESchool childrensocioeconomic statuemotional and behavioral difficultiesPsychologysocial emotional competencemulti-informant assessmentGeneral PsychologyFrontiers in Psychology
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β-Catenin Activation Regulates Tissue Growth Non–Cell Autonomously in the Hair Stem Cell Niche

2014

Coordinated Hair Growth Wnt/β-catenin signaling is a key pathway that plays a conserved role in regulating stem cell function during adult tissue regeneration. Using time-lapse imaging of live mice, Deschene et al. (p. 1353 ) show that genetic activation of β-catenin within hair follicle stem cells generates axes of hair growth by coordinated cell divisions and cell movements, even when the normal niches—the dermal papillae—are laser-ablated. Activated β-catenin enhances Wnt ligand secretion, and these ligands can then activate Wnt signaling in adjacent cells that do not have activated β-catenin, indicating how activated stem cells could influence neighboring cells during normal growth and …

Beta-cateninWnt ProteinCellular differentiationLigandBiologyLigandsModels BiologicalArticleMiceStem CellmedicineAnimalsStem Cell NicheAnimals; Cell Differentiation; Cell Division; Hair; Hair Follicle; Ligands; Mice; Models Biological; Mutation; Stem Cell Niche; Stem Cells; Tamoxifen; Up-Regulation; Wnt Proteins; beta Catenin; Wnt Signaling Pathway; Medicine (all); MultidisciplinaryWnt Signaling Pathwaybeta CateninMultidisciplinaryintegumentary systemAnimalStem CellsMedicine (all)Regeneration (biology)Mesenchymal stem cellWnt signaling pathwayCell DifferentiationHair follicleUp-RegulationCell biologyWnt ProteinsTamoxifenmedicine.anatomical_structureCateninMutationbiology.proteinStem cellHair FollicleCell DivisionHairScience
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Modelling and development of a generic observatory to harvest and analyze big data

2021

Big Data fascinate, both because of the value they hold that can provide a significant advantage in decision-making, and because of the challenges that their exploitation represents. These challenges are present at several levels of analytics workflows. At the level of the creation of software architectures, the volume and the velocity require at least enough performance to handle the ingestion and storage of data. The data variety has also an impact, as several new storage systems have emerged, each one corresponding to a specific need. The polystores are systems that integrate this diversity, to gain flexibility compared to the data warehouses, now too rigid. However, this diversification…

Big DataStream processing[INFO.INFO-OH] Computer Science [cs]/Other [cs.OH]TenseursData modelsCategory TheoryArchitectures logiciellesTensorsThéorie des catégoriesDonnées massivesModèles de donnéesSoftware Architectures
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The efficiency of LiDAR HMLS scanning in monitoring forest structure parameters: implications for sustainable forest management

2022

PurposeThis article aims to compare the LiDAR handheld mobile laser scanner (HMLS) scans with traditional survey methods, as the tree gauge and the hypsometer, to study the efficiency of the new technology in relation to the accuracy of structural forest attributes estimation useful to support a sustainable forest management.Design/methodology/approachA case study was carried out in a high forest located in Tuscany (Italy), by considering 5 forest types, in 20 different survey plots. A comparative analysis between two survey methods will be shown in order to verify the potential limits and the viability of the LiDAR HMLS in the forest field.FindingsThis research demonstrates that LiDAR HMLS…

Big data Organisational efficiency Digitalisation Sustainable business models Forest structure Precision forestry LIDAR HMLS.General Business Management and AccountingFinanceEuroMed Journal of Business
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Estimation of total electricity consumption curves of small areas by sampling in a finite population

2016

International audience; Many studies carried out in the French electricity company EDF are based on the analysis of the total electricity consumption curves of groups of customers. These aggregated electricity consumption curves are estimated by using samples of thousands of curves measured at a small time step and collected according to a sampling design. Small area estimation is very usual in survey sampling. It is often addressed by using implicit or explicit domain models between the interest variable and the auxiliary variables. The goal here is to estimate totals of electricity consumption curves over domains or areas. Three approaches are compared: the rst one consists in modeling th…

Big dataEnergyMSC: 62H25Functional principal component analysis[MATH.MATH-ST]Mathematics [math]/Statistics [math.ST]Regression trees[ MATH.MATH-ST ] Mathematics [math]/Statistics [math.ST]Mixed modelsFunctional data[MATH.MATH-ST] Mathematics [math]/Statistics [math.ST]
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Memristors in Nonlinear Network : Application to Information (Signal and Image) Processing

2021

Memristor is a two-terminal nonlinear dynamic electronic device. Typically, it is a passive nano-device whose conductivity is controlled by the flux, time-integral of the voltage across its terminals, or by the charge, time-integral of the current flowing through it, and it presents interesting features for versatile applications. This thesis considers memristor use as a neighborhood connection for 2D cellular nonlinear or neural network (CNN), essentially for information (image and signal) processing and electronic prosthesis. We develop a model of the memristor based 2D cellular nonlinear networks CNNs compatible to image applications by incorporating memristor in the adjacent neighborhoo…

BilateralityMemristor and modelsSignal and image processingRéseau 2 dimensions[INFO.INFO-OH]Computer Science [cs]/Other [cs.OH]Bilatéralité2 dimensional networks[INFO.INFO-OH] Computer Science [cs]/Other [cs.OH]Propagation (réseau 1D)Fitzhugh-Nagumo cellsTraitement du signal et de l'imageFitzhugh-Nagumo cellulesPropagation (1D network)Memristor et models
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