Resource dedication problem in a multi-project environment

There can be different approaches to the management of resources within the context of multi-project scheduling problems. In general, approaches to multiproject scheduling problems consider the resources as a pool shared by all projects. On the other hand, when projects are distributed geographically or sharing resources between projects is not preferred, then this resource sharing policy may not be feasible. In such cases, the resources must be dedicated to individual projects throughout the project durations. This multi-project problem environment is defined here as the resource dedication problem (RDP). RDP is defined as the optimal dedication of resource capacities to different projects within the overall limits of the resources and with the objective of minimizing a predetermined objective function. The projects involved are multi-mode resource constrained project scheduling problems with finish to start zero time lag and non-preemptive activities and limited renewable and nonrenewable resources. Here, the characterization of RDP, its mathematical formulation and two different solution methodologies are presented. The first solution approach is a genetic algorithm employing a new improvement move called combinatorial auction for RDP, which is based on preferences of projects for resources. Two different methods for calculating the projects’ preferences based on linear and Lagrangian relaxation are proposed. The second solution approach is a Lagrangian relaxation based heuristic employing subgradient optimization. Numerical studies demonstrate that the proposed approaches are powerful methods for solving this problem

ULTRASONIC LIGHT DIFFRACTION FOR THE CASE OF THE INTENSE LASER BEAM GENERATING A 3rd HARMONIC IN LIQUIDS

Un calcul de la diffraction par une onde ultrasonore de la lumière intense émise par un laser est exposé dans le cas du sulfure de carbone, du tétrachlorure de carbone et du benzène. Des essais ont été effectués pour trouver les conditions expérimentales qui confirment les prévisions théoriques.Some calculations of the intensity distributions of intense laser light diffracted on an ultrasonic wave were made for carbon disulfide, carbon tetrachloride and benzene. Attempts have been made to find some proper conditions for the experiment to prove theoretical predictions

A constraint generation approach for the two-machine flow shop problem with jobs selection

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