We study methods that improve scheduling robustness under uncertain disturbances and dynamic shop conditions. A new method is proposed based on the notion of preprocessrst-schedule-later by Wu et al. [19]. Preprocessing starts at the beginning of the planning period where we use a Lagrangean Relaxation of the scheduling model to form networkstructured job subproblems. For each job subproblem we...

In virtual circuit networks, all the packets in a session are transmitted over exactly one path established between the origin and the destination. For each origin-destination pair, it is assumed that there are multiple sessions. We consider the problem of choosing a path for each session so as to minimize the average packet delay in the network. We formulate this problem as a nonlinear multico...

We propose a new comprehensive solution to global interconnect optimization. Traditional buffering algorithms mostly insert repeaters on net-by-net basis based slacks and possibly guided by wires. show how integrate routing congestion, placement timing constraints, power consumption, additional constraints into single resource sharing formulation. The core of our algorithm is buffered subroutin...

In this study we analyze the performance of a Lagrangean relaxation upper bound for the problem of packing the maximum number of rectangles of sizes (l; w) and (w; l) into a larger rectangle (L;W ) without overlapping. This problem appears in the loading of identical boxes on pallets, namely the manufacturer’s pallet loading problem (MPL), as well as in package design and truck or rail car load...

We show that if the Lagrangean for a scalar field coupled to General Relativity only contains derivatives, then it is possible to completely deparametrise the theory. This means that 1. Physical observables, i.e. functions which Poisson commute with the spatial diffeomorphism and Hamiltonian constraints of General Relativity, can be easily constructed. 2. The physical time evolution of those ob...

A tabu search heuristic procedure for the capacitated facility location problem is developed, implemented and computationally tested. The heuristic procedure uses both short term and long term memories to perform the main search process as well as the diversification and intensification functions. Visited solutions are stored in a primogenitary linked quad tree as a long term memory. The recent...