Showing papers by "HEC Montréal published in 1995"

An Optimal Algorithm for the Traveling Salesman Problem with Time Windows

Abstract: This paper presents the development of new elimination tests which greatly enhance the performance of a relatively well established dynamic programming approach and its application to the minimization of the total traveling cost for the traveling salesman problem with time windows. The tests take advantage of the time window constraints to significantly reduce the state space and the number of state transitions. These reductions are performed both a priori and during the execution of the algorithm. The approach does not experience problems stemming from increasing problem size, wider or overlapping time windows, or an increasing number of states nearly as rapidly as other methods. Our computational results indicate that the algorithm was successful in solving problems with up to 200 nodes and fairly wide time windows. When the density of the nodes in the geographical region was kept constant as the problem size was increased, the algorithm was capable of solving problems with up to 800 nodes. For these problems, the CPU time increased linearly with problem size. These problem sizes are much larger than those of problems previously reported in the literature.

Strategy and organization theories: common forms of discourse*

Abstract: Attempts at developing a taxonomic classification scheme for knowledge in the area of strategy contain major shortcomings. VVith the aim of breaking through the limitations inherent in these classification efforts, this article rejects the idea that strategic discourse is autonomous, and proposes instead that organization theories be considered, since these allow for the development of discursive forms in the field of strategy. Four types of strategic discourse are identified; these are the classical, contingency, socio-political and socio-cognitive forms. The authors also stress the importance of developing a critical form of discourse in this area of study.

Exchange Rates and Oil Prices

Abstract: The authors document a robust and interesting relationship between the real domestic price of oil and real effective exchange rates for Germany, Japan and the United States. They explain why they think the real oil price captures exogenous terms-of-trade shocks and why such shocks could be the most important factor determining real exchange rates in the long run.

Differential Game Models of Global Environmental Management

Abstract: This paper deals with the modeling of economy-environment interactions for several countries which are assumed to behave competitively for the control of their own economic processes but have to achieve jointly a common environmental management goal. The paper is organized in two parts treating of modeling issues related to process dynamics and players interactions respectively. In the first part we discuss the control theoretic approach for representing the economic and pollution processes in a model of environmental management. We also give a short discussion of a possible representation of uncertainty and risk in these models. In part two we propose a dynamic game modeling approach which combines two classic models, the N-person equilibrium model with coupled constraints proposed by Rosen and the differential game model with active and passive variables proposed by Brock. These models permit the definition of a tax scheme which induces a set of equilibrium seeking players to achieve, in the long run, a global environmental goal.