In this paper we formulate the fuzzy bilevel programming problem and describe one possible approach for formulating a crisp optimization problem being attached to it. Due to the nature of fuzzy bilevel programming this is a crisp bilevel programming problem. We compare our approach with one using multicriterial optimization and show, that both approaches are basically different. The use of mult...

This paper presents a fuzzy approach for solving the bi-level integer linear fractional programming problem (BILFPP). At the first phase of the solution algorithm and to avoid the complexity of non convexity of this problem, we begin by finding the convex hull of its original set of constraints using the cutting-plane algorithm, and then the Charnes & Cooper transformation is used to convert th...

We consider the bilevel programming problem with a special lower level. As a reformulation, we use the optimal value approach which will be the basis for an outer approximation. We establish an algorithm that sequentially improves the approximation in order to solve the bilevel programming problem. Convergence results for both local and global optima are presented.

We extend some known results about the Bilevel Linear Problem (BLP), a hierarchical two-stage optimization problem, showing how it can be used to reformulate any Mixed Integer (Linear) Problem; then, we introduce some new concepts, which might be useful to fasten almost all the known algorithms devised for BLP. As this kind of reformulation appears to be somewhat artificial, we define a natural...

This paper presents a genetic algorithm method for solving convex quadratic bilevel programming problem. Bilevel programming problems arise when one optimization problem, the upper problem, is constrained by another optimization, the lower problem. In this paper, the bilevel convex quadratic problem is transformed into a single level problem by applying Kuhn-Tucker conditions, and then an effic...

Organizational decision making often involves two decision levels. When the leader at the upper level attempts to optimize hislher objective, the follower at the lower level tries to find an optimized strategy according to each of possible decisions made by the leader. Furthermore, such bilevel decision making may involve uncertain parameters which appear either in the objective functions or co...