By means of a model based on a set covering formulation, it is shown how the p-Median Problem can be solved with just a column generation approach, which is embedded in a branch-and-bound framework based on dynamic reliability branching. This method is more than competitive in terms of computational times and size of the instances which have been optimally solved. In particular, problems of siz...

This paper discusses the planning problem of a group of domestic Combined Heat and Power (microCHP) appliances, which together form a Virtual Power Plant (VPP). To act on an electricity trading market, this VPP has to specify a production plan for electricity for given times of the day to offer to this market. These amounts have to be delivered exactly when these times arrive; moreover, deviati...

We consider a probabilistic constrained stochastic programming problem with discrete random variables. Two methods, a cutting plane and a column generation method have already been developed for the solution of the problem. In this paper we blend them together and obtain a method that is faster than the earlier ones. We also present a refined algorithm for the generation of p-level efficient po...

We propose a game theoretic model for the spatial distribution of inspectors on a transportation network. The problem is to spread out the controls so as to enforce the payment of a transit toll. We formulate a linear program to find the control distribution which maximizes the expected toll revenue, and a mixed integer program for the problem of minimizing the number of evaders. Furthermore, w...

Submitted Abstract We use column generation and a specialized branching technique for solving constrained clustering problems. We also develop and implement an innovative com-binatorial method for solving the pricing subproblems. Computational experiments comparing the resulting branch-and-price method to competing methodologies in the literature are presented and suggest that our technique yie...

In this paper we introduce the problem of shunting passenger train units in a railway station. Shunting occurs whenever train units are temporarily not necessary to operate a given timetable. We discuss several aspects of this problem and focus on two subproblems. We propose mathematical models for these subproblems together with a solution method based on column generation. Furthermore, a new ...

The Team Orienteering Problem is a routing problem on a graph with durations associated to the arcs and profits assigned to visiting the vertices. A fixed number of identical vehicles, with a limited total duration for their routes, is given. The total profit gathered by all routes is to be maximized. We devise an extended formulation where edges are indexed by the time they are placed in the r...

W e consider the problem of balancing two competing objectives in the pursuit of efficient management of operating rooms in a hospital: providing surgeons with predictable, reliable access to the operating room and maintaining high utilization of capacity. The common solution to the first problem (in practice) is to grant exclusive " block time, " in which a portion of the week in an operating ...

We consider the application of Dantzig-Wolfe decomposition to stochastic integer programming problems arising in the capacity planning of electricity transmission networks that have some switchable transmission elements. The decomposition enables a column-generation algorithm to be applied, which allows the solution of large problem instances. The methodology is illustrated by its application t...

This work presents an integer programming formulation for a variant of the Class-Teacher Timetabling problem, which considers the satisfaction of teacher preferences and also the proper distribution of lessons throughout the week. The formulation contains a very large number of variables and is enhanced by cuts. Therefore, a cut and column generation algorithm to solve its linear relaxation is ...