Scheduling internal audit activities:A stochastic combinatorial optimization problem

The problem of finding the optimal timing of audit activities within an organisation has been addressed by many researchers. We propose a stochastic programming formulation with Mixed Integer Linear Programming (MILP) and Constraint Programming (CP) certainty-equivalent models. In experiments neither approach dominates the other. However, the CP approach is orders of magnitude faster for large audit times, and almost as fast as the MILP approach for small audit times. This work generalises a previous approach by relaxing the assumption of instantaneous audits, and by prohibiting concurrent auditin

LARGE DEVIATIONS FROM CLASSICAL PATHS - HAMILTONIAN FLOWS AS CLASSICAL LIMITS OF QUANTUM FLOWS

Blanchard P, SIRUGUE M. LARGE DEVIATIONS FROM CLASSICAL PATHS - HAMILTONIAN FLOWS AS CLASSICAL LIMITS OF QUANTUM FLOWS. COMMUNICATIONS IN MATHEMATICAL PHYSICS. 1985;101(2):173-185

Structure and dynamics of multicellular assemblies measured by coherent light scattering

International audienceDetermining the structure and the internal dynamics of tissues is essential to understand their functional organization. Microscopy allows monitoring positions and trajectories of every single cell. Those data are useful to extract statistical observables, such intercellular distance, tissue symmetry and anisotropy, and cell motility. However, this procedure requires a large and supervised computational effort. In addition, due to the large cross-section of cells, the light scattering limits the use of microscopy to relatively thin samples. As an alternative approach, we propose to take advantage of light scattering and to analyze the dynamical diffraction pattern produced by a living tissue illuminated with coherent light. In this article, we illustrate with few examples that supra-cellular structures produce an exploitable diffraction signal. From the diffraction signal, we deduce the mean distance between cells, the anisotropy of the supra-cellular organization and, from its fluctuations, the mean speed of moving cells. This easy to implement technique considerably reduces analysis time, allowing real time monitoring