A note on optimality conditions for dual problems to the traveling salesman problem
A Note on Small Linear-Ordering Polytopes.
A Note on the Improvement of the Maximum Independent Set's Approximation Ratio
A polyhedral study of a two level facility location model
We study an uncapacitated facility location model where customers are served by facilities of level one, then each level one facility that is opened must be assigned to an opened facility of level two. We identify a polynomially solvable case, and study some valid inequalities and facets of the associated polytope.
A relation between the approximated versions of minimum set covering, minimum vertex covering and maximum independent set
A service points location problem with Min-Max distance optimality criterion
A solvable case of the set-partitioning problem
A sparse dynamic programming algorithm for alignment with non-overlapping inversions
Alignment of sequences is widely used for biological sequence comparisons, and only biological events like mutations, insertions and deletions are considered. Other biological events like inversions are not automatically detected by the usual alignment algorithms, thus some alternative approaches have been tried in order to include inversions or other kinds of rearrangements. Despite many important results in the last decade, the complexity of the problem of alignment with inversions is still unknown....
A sparse dynamic programming algorithm for alignment with non-overlapping inversions
Alignment of sequences is widely used for biological sequence comparisons, and only biological events like mutations, insertions and deletions are considered. Other biological events like inversions are not automatically detected by the usual alignment algorithms, thus some alternative approaches have been tried in order to include inversions or other kinds of rearrangements. Despite many important results in the last decade, the complexity of the problem of alignment with inversions is...
A Survey of some Non-Standard Traveling Salesman Problems
A survey on combinatorial optimization in dynamic environments∗
This survey presents major results and issues related to the study of NPO problems in dynamic environments, that is, in settings where instances are allowed to undergo some modifications over time. In particular, the survey focuses on two complementary frameworks. The first one is the reoptimization framework, where an instance I that is already solved undergoes some local perturbation. The goal is then to make use of the information provided by the initial solution to compute a new solution. The...
A survey on combinatorial optimization in dynamic environments∗
This survey presents major results and issues related to the study of NPO problems in dynamic environments, that is, in settings where instances are allowed to undergo some modifications over time. In particular, the survey focuses on two complementary frameworks. The first one is the reoptimization framework, where an instance I that is already solved undergoes some local perturbation. The goal is then to make use of the information provided by the initial solution to compute a new solution. The...
A trust region method for zero-one nonlinear programming
Acyclic orientations with path constraints
Many well-known combinatorial optimization problems can be stated over the set of acyclic orientations of an undirected graph. For example, acyclic orientations with certain diameter constraints are closely related to the optimal solutions of the vertex coloring and frequency assignment problems. In this paper we introduce a linear programming formulation of acyclic orientations with path constraints, and discuss its use in the solution of the vertex coloring problem and some versions of the frequency...
Acyclic Orientations with Path Constraints
Many well-known combinatorial optimization problems can be stated over the set of acyclic orientations of an undirected graph. For example, acyclic orientations with certain diameter constraints are closely related to the optimal solutions of the vertex coloring and frequency assignment problems. In this paper we introduce a linear programming formulation of acyclic orientations with path constraints, and discuss its use in the solution of the vertex coloring problem and some versions of the frequency...
Agrégation des similarités : une solution oubliée
Le problème de l’agrégation des similarités signées est résolu à l’aide d’une version dérivant de l’algorithme booléen de Faure et Malgrange. La méthode s’applique à des similarités entières ou réelles, et permet l’énumération des solutions multiples. Elle nécessite une quantité de mémoire égale à trois fois la taille des données d’entrée.
Agrégation des similarités : une solution oubliée
The signed similarities aggregation problem is solved with a boolean method derived from the Faure and Malgrange algorithm. The method is adequate either for integer similarities or real similarites, and multiple solutions can be enumerated. It needs a space amount equal to three times the input data size.
Algorithmes génétiques hybrides pour l'optimisation combinatoire
Algorithms for the two dimensional bin packing problem with partial conflicts
The two-dimensional bin packing problem is a well-known problem for which several exact and approximation methods were proposed. In real life applications, such as in Hazardous Material transportation, transported items may be partially incompatible, and have to be separated by a safety distance. This complication has not yet been considered in the literature. This paper introduces this extension called the two-dimensional bin packing problem with partial conflicts (2BPPC) which is a 2BP with distance...
Algorithms for the two dimensional bin packing problem with partial conflicts
The two-dimensional bin packing problem is a well-known problem for which several exact and approximation methods were proposed. In real life applications, such as in Hazardous Material transportation, transported items may be partially incompatible, and have to be separated by a safety distance. This complication has not yet been considered in the literature. This paper introduces this extension called the two-dimensional bin packing problem with partial conflicts (2BPPC) which is a 2BP with distance...