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This paper is concerned with prognostic information for maintenance and production optimization in complex systems. In each stage of such a system, we allow redundant components used as backup to ensure system's availability. Remaining Useful Life (RUL, the so-called prognostic information) of components is used to evaluate each component's redundancy. We address RUL-based maintenance and production optimization to guarantee the availability and productivity of the system such that client demands can be satisfied in a given planning horizon. We propose a mixed-integer linear programming model to minimize the total cost. Experimental results on test instances show the efficiency of the proposed approach to attain optimal solutions.

International audience

International audience; Cloud-Radio Access Network is a promising mobile network architecture that centralizes the computing resources in the Baseband Unit pool which adds more flexibility and increases network performance. However, as computing resources are shared among the Radio Remote Heads (RRH) connected to the Baseband Unit pool, efficient scheduling algorithms should be explored to meet the deadlines requirements of RRHs' subframes and to increase the network throughput. In this paper, we propose optimal scheduling algorithms for computing resources along with three heuristics. We test the different algorithms as a function of three metrics. The evaluation is performed under a real traffic model and the results highlight the importance of choosing the appropriate scheduling algorithm to increase network performance.

International audience

International audience

International audience; This article focuses on the problem of computing a minimum-weight subgraph with unicyclic connected components. Although this problem is generally easy, it becomes difficult when a girth constraint is added. A polyhedral study is proposed. Many facets and valid inequalities are derived. Some of them can be exactly separated in polynomial time. Hence, the problem is solved by a cutting-plane algorithm based on these inequalities and using a compact formulation derived from the transversality of the bicircular matroid. Numerical results are also presented.

International audience; *

International audience; Let G a weighted connexe graph. In this paper, we are interesting by covering the vertices of G by connexe disjoints unicyclic components with minimum total cost. We propose two polynomial algorithms, the first is based on the construction of a matroïd on this graph, and the second is to calculate in polynomial time a maximum matching with minimum cost on an induced graph constructed on the initial one. We prove that this two methods have the same result which is disjoints connexe unicyclic components with minimum total cost. In a second time, we are interesting by obtain a partition of unicyclic components with a minimum total cost by adding a girth constraint. Then the problem becomes difficult, and to solve it, we propose a polyhedral study in which we show many facets and valid inequalities. Some of them can be exactly separated in polynomial time. Then we solve the problem by a cutting plane algorithm based on these inequalities and using a compact formulation issued from the transversality of the bicircular matroïd. We also show a new valid inequality related to the upper bound of the number of unicyclic components obtained after the partition. The problem has practical and important applications in the design of telecommunication networks