Browsing CEGI - Indexed Articles in Conferences by Author "Ana Viana"
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ItemA compact formulation for maximizing the expected number of transplants in kidney exchange programs( 2015) Alvelos,F ; Xenia Klimentova ; Rais,A ; Ana VianaKidney exchange programs (KEPs) allow the exchange of kidneys between incompatible donor-recipient pairs. Optimization approaches can help KEPs in defining which transplants should be made among all incompatible pairs according to some objective. The most common objective is to maximize the number of transplants. In this paper, we propose an integer programming model which addresses the objective of maximizing the expected number of transplants, given that there are equal probabilities of failure associated with vertices and arcs. The model is compact, i.e. has a polynomial number of decision variables and constraints, and therefore can be solved directly by a general purpose integer programming solver (e.g. Cplex).
ItemA Compact Formulation for the Kidney Exchange Problem( 2012) Abdur Rais ; Miguel Cosntantino ; Xenia Klimentova ; Ana Viana ; João Pedro Pedroso
ItemA MILP-Based Approach for Hydrothermal Scheduling( 2014) Dewan Fayzur Rahman ; Ana Viana ; João Pedro Pedroso
ItemA New Branch-and-Price Approach for the Kidney Exchange Problem( 2014) Xenia Klimentova ; Alvelos,F ; Ana VianaThe kidney exchange problem (KEP) is an optimization problem arising in the framework of transplant programs that allow exchange of kidneys between two or more incompatible patient-donor pairs. In this paper an approach based on a new decomposition model and branch-and-price is proposed to solve large KEP instances. The optimization problem considers, hierarchically, the maximization of the number of transplants and the minimization of the size of exchange cycles. Computational comparison of different variants of branch-and-price for the standard and the proposed objective functions are presented. The results show the efficiency of the proposed approach for solving large instances.
ItemNew Integer Programming formulations for the Kidney Exchange Problem( 2012) Ana Viana ; Xenia Klimentova ; Miguel Constantino