26 research outputs found
The Genetic Code Degeneration I: Rules Governing the Code Degeneration and the Spatial Organization of the Codon Informative Properties
The present work is devoted to describe a set of rules explaining the
discriminating versus non-discriminating behavior of the di-basic stages and to
characterize the role of each base in determining such a behavior. Bases are
analyze as dual entities characterized by its chemical type and the number of H
bonds involved in the codon-anticodon interaction. A codon is characterized as
an asymmetric informative entity whose global informative capacity results from
the spatially organized combinatory of the 6 proper-ties assigned by the 3
bases
Modelling the spatial organization of cell proliferation in the developing central nervous system
How far is neuroepithelial cell proliferation in the developing central
nervous system a deterministic process? Or, to put it in a more precise way,
how accurately can it be described by a deterministic mathematical model? To
provide tracks to answer this question, a deterministic system of transport and
diffusion partial differential equations, both physiologically and spatially
structured, is introduced as a model to describe the spatially organized
process of cell proliferation during the development of the central nervous
system. As an initial step towards dealing with the three-dimensional case, a
unidimensional version of the model is presented. Numerical analysis and
numerical tests are performed. In this work we also achieve a first
experimental validation of the proposed model, by using cell proliferation data
recorded from histological sections obtained during the development of the
optic tectum in the chick embryo
On unbounded solutions of Bellman's equation associated to optimal switching control problems with state constraints
Projet ASWe study a QVI system with unbounded solutions. It represents the Bellman equation associated to an optimal switching control problem with state constraints arising from production engineering. We show that the optimal cost is the unique viscosity solution of the system
The Genetic Code Degeneration I: Rules Governing the Code Degeneration and the Spatial Organization of the Codon Informative Properties.
the present work is devoted to describe a set of rules explaining the discriminating versus non-discriminating behavior of the di-basic stages and to characterize the role of each base in determining such a behavior. Bases are analyze as dual entities characterized by its chemical type and the number of H bonds involved in the codon-anticodon interaction. A codon is characterized as an asymmetric informative entity whose global informative capacity results from the spatially organized combinatory of the 6 proper-ties assigned by the 3 bases
Optimal control of arborescent multilevel inventory - production systems
Projet PROMATHWe present a model for globally optimizing arborescent multilevel inventory-production problems. State-space constraints as well as Poisson distributed demands arriving at any node are considered. For the numerical solution a rate of convergence of order h.Inh is obtained.We introduce a new algorithm for the fast computation of the numerical solution which allows the resolution of complex problems. Some numerical results are shown. We also study the advantages of cooperative behaviour of nodes versus decentralized optimization
Quasi-variational inequality approach to multi-item single machine lot scheduling problem
Projet PROMATHWe study in this paper the optimization of a production system comprising a multi-item single machine. Taking into account the switching-costs, we analyze the optimization of the system in terms of a system of Quasi-Variational-Inequalities (QVI) which due to the presence of state restrictions, has unbounded solutions. This system represents the Bellman equation associated to this optimal switching control problem. We study the structure of this QVI system, its solutions and numerical methods to solve it