0000000000409828

AUTHOR

Ulrich Razafison

showing 2 related works from this author

Identifiability problem for recovering the mortality rate in an age-structured population dynamics model

2014

In this article is studied the identifiability of the age-dependent mortality rate of the Von Foerster–Mc Kendrick model, from the observation of a given age group of the population. In the case where there is no renewal for the population, translated by an additional homogeneous boundary condition to the Von Foerster equation, we give a necessary and sufficient condition on the initial density that ensures the mortality rate identifiability. In the inhomogeneous case, modelled by a non-local boundary condition, we make explicit a sufficient condition for the identifiability property, and give a condition for which the identifiability problem is ill-posed. We illustrate this latter case wit…

age-structured modelAge structurePopulation35Q92 35R30 92D25 93B3001 natural sciencestransport PDE[ MATH.MATH-AP ] Mathematics [math]/Analysis of PDEs [math.AP]Statisticspopulation dynamicsApplied mathematicsQuantitative Biology::Populations and Evolution[MATH.MATH-AP]Mathematics [math]/Analysis of PDEs [math.AP]Boundary value problem0101 mathematicseducationMathematicseducation.field_of_studyParameter identifiabilityApplied MathematicsMortality rate010102 general mathematicsGeneral EngineeringInverse problemComputer Science Applications010101 applied mathematicsnon-local boundary conditionHomogeneousIdentifiability
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Analysis and approximation of one-dimensional scalar conservation laws with general point constraints on the flux

2016

We introduce and analyze a class of models with nonlocal point constraints for traffic flow through bottlenecks, such as exits in the context of pedestrians traffic and reduction of lanes on a road under construction in vehicular traffic. Constraints are defined based on data collected from non-local in space and/or in time observations of the flow. We propose a theoretical analysis and discretization framework that permits to include different data acquisition strategies; a numerical comparison is provided. Nonlocal constraint allows to model, e.g., the irrational behavior (" panic ") near the exit observed in dense crowds and the capacity drop at tollbooth in vehicular traffic. Existence …

Crowd dynamicsMathematical optimizationFixed point argumentsDiscretizationGeneral MathematicsScalar (mathematics)Crowd dynamics; Finite volume approximation; Nonlocal point constraint; Scalar conservation law; Vehicular traffics; Well-posedness; Mathematics (all); Applied Mathematics01 natural sciencesMSC : 35L65 90B20 65M12 76M12NONonlocal point constraintCrowdsData acquisitionMathematics (all)[MATH.MATH-AP]Mathematics [math]/Analysis of PDEs [math.AP]DoorsUniqueness[MATH.MATH-AP] Mathematics [math]/Analysis of PDEs [math.AP]0101 mathematicsScalar conservation lawMathematicsConservation lawVehicular trafficsFinite volume methodApplied Mathematics010102 general mathematics[MATH.MATH-NA] Mathematics [math]/Numerical Analysis [math.NA]010101 applied mathematicsWell-posednessFinite volume schemeFinite volume approximationConvergence of approximations[MATH.MATH-NA]Mathematics [math]/Numerical Analysis [math.NA]Journal de Mathématiques Pures et Appliquées
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