Dévelopement d'une politique de maintenance d'un dispositif médical dont la dégradation est influencée par l'utilisation

International audienceet article traite un problème de maintenance périodique d'un dispositif médical dans le milieu hospitalier. Le problème consiste en un dispositif médical satisfaisant une demande aléatoire de patients (le nombre de patient qui subissent mensuellement le diagnostic sur le dispositif médical est variable).  L'objet de l'étude consiste à développer une politique de maintenance qui a pour but de minimiser le coût total de maintenance. Pour développer le modèle d'optimisation, nous avons pris en considération l'influence du taux d'utilisation du système sur sa dégradation. Une étude analytique et un exemple numérique sont présentés afin de prouver l'approche développée.</p

Coordinated multi-criteria scheduling of caregivers in home health Care Services

International audienceHome health Care Services (HCS) that provides continuous and coordinated cares at patients' home. This paper addresses the problem of scheduling care activities, performed by caregivers belonging to a HCS. Care visits for the same patient might be done in some order (coordinated). The problem consists in determining a tour for all caregivers in order to optimize multiple criteria. We propose two mixed integer programming (MILP) models, each corresponding to a scheduling strategy. Numerical results are given to show the relationship between patient waiting times and caregiver working durations

ROUTING AND SCHEDULING OF CAREGIVERS IN HOME HEALTH CARE WITH SYNCHRONIZED VISITS

International audienc

Microscopic Study of Superdeformed Rotational Bands in 151Tb

Structure of eight superdeformed bands in the nucleus 151Tb is analyzed using the results of the Hartree-Fock and Woods-Saxon cranking approaches. It is demonstrated that far going similarities between the two approaches exist and predictions related to the structure of rotational bands calculated within the two models are nearly parallel. An interpretation scenario for the structure of the superdeformed bands is presented and predictions related to the exit spins are made. Small but systematic discrepancies between experiment and theory, analyzed in terms of the dynamical moments, J(2), are shown to exist. The pairing correlations taken into account by using the particle-number-projection technique are shown to increase the disagreement. Sources of these systematic discrepancies are discussed -- they are most likely related to the yet not optimal parametrization of the nuclear interactions used.Comment: 32 RevTeX pages, 15 figures included, submitted to Physical Review

Level Structure of 103Ag at high spins

High spin states in $^{103}$Ag were investigated with the Gammasphere array, using the $^{72}$Ge($^{35}$Cl,$2p2n$)$^{103}$Ag reaction at an incident beam energy of 135 MeV. A $\Delta J$=1 sequence with predominantly magnetic transitions and two nearly-degenerate $\Delta J=1$ doublet bands have been observed. The dipole band shows a decreasing trend in the $B(M1)$ strength as function of spin, a well established feature of magnetic bands. The nearly-degenerate band structures satisfy the three experimental signatures of chirality in the nuclei; however microscopic calculations are indicative of a magnetic phenomeno

Time-odd components in the mean field of rotating superdeformed nuclei

Rotation-induced time-odd components in the nuclear mean field are analyzed using the Hartree-Fock cranking approach with effective interactions SIII, SkM*, and SkP. Identical dynamical moments ${{\cal J}^{(2)}}$ are obtained for pairs of superdeformed bands $^{151}$Tb(2)--$^{152}$Dy(1) and $^{150}$Gd(2)--$^{151}$Tb(1). The corresponding relative alignments strongly depend on which time-odd mean-field terms are taken into account in the Hartree-Fock equations.Comment: 23 pages, ReVTeX, 6 uuencoded postscript figures include