We address a spatial conservation planning problem in which the planner purchases a budgetconstrained set of land parcels in order to maximize the expected spread of a population of an endangered species. Existing techniques based on the sample average approximation scheme and standard integer programming methods have high complexity and limited scalability. We propose a fast combinatorial opti...

In this paper, we address the rate control problem for layered multicast sessions, with the objective of solving a generalized throughput/fairness objective. Our approach is based on a combination of lagrangian relaxation and dynamic programming. Unlike previously proposed dual-based approaches, the algorithm presented in this paper scales well as the number of multicast groups in the network i...

This paper describes a comprehensive course timetabling and student scheduling system that was developed for the University of Waterloo between 1979 and 1985. The system is based on a “demand-driven” philosophy where students first chose their courses, and the system tries to find the best timetable to maximize the number of satisfied requests. The problem is first decomposed into small managea...

We study the following problem k-constrained shortest path problem: given an acyclic directed graph D = (V,E) with arc weights ci,j , (i, j) ∈ E, two nodes s and t and an integer k, nd a shortest st-path containing at most k arcs. An important application of the problem in linear curve approximation is discussed. Vertices and edges of associated polytopes are determined, and integrality of thes...

We investigate new methods for generating Lagrangian cuts to solve two-stage stochastic integer programs. can be added a Benders reformulation, and are derived from solving single scenario programming subproblems identical those used in the nonanticipative dual of program. While have potential significantly strengthen relaxation, computationally demanding. techniques with goal obtaining that pr...

We present an integrated schedule planning model where the decisions of schedule design, fleeting and pricing are made simultaneously. Pricing is integrated through a logit demand model where itinerary choice is modeled by defining the utilities of the alternative itineraries. Spill and recapture effects are appropriately incorporated in the model by using a logit formulation similar to the dem...

We consider the hub location problem, where p hubs are chosen from a given set of nodes, each nonhub node is connected to exactly one hub and each hub is connected to a central hub. Links are installed on the arcs of the resulting network to route the traffic. The aim is to find the hub locations and the connections to minimize the link installation cost. We propose two formulations and a heuri...

With the increasing density of VLSI circuits, interconnection wires are getting packed even closer. This has increased the effect of interaction between wires on circuit performance and hence, the importance of controlling crosstalk. Maze routing is a robust and general approach which can be used in many situations including multi-layer interconnections. In this paper, we consider crosstalk avo...