Polynomial algorithms for p-dispersion problems in a 2d Pareto Front

Having many best compromise solutions for bi-objective optimization problems, this paper studies p-dispersion problems to select $p\geqslant 2$ representative points in the Pareto Front(PF). Four standard variants of p-dispersion are considered. A novel variant, denoted Max-Sum-Neighbor p-dispersion, is introduced for the specific case of a 2d PF. Firstly, it is proven that $2$-dispersion and $3$-dispersion problems are solvable in $O(n)$ time in a 2d PF. Secondly, dynamic programming algorithms are designed for three p-dispersion variants, proving polynomial complexities in a 2d PF. The Max-Min p-dispersion problem is proven solvable in $O(pn\log n)$ time and $O(n)$ memory space. The Max-Sum-Min p-dispersion problem is proven solvable in $O(pn^3)$ time and $O(pn^2)$ space. The Max-Sum-Neighbor p-dispersion problem is proven solvable in $O(pn^2)$ time and $O(pn)$ space. Complexity results and parallelization issues are discussed in regards to practical implementation

Matheuristics to stabilize column generation: application to a technician routing problem

International audienceThis paper considers a simplified Technician Routing and Scheduling Problem with skill constraints, where a Column Generation (CG) heuristic was shown effective. This work proposes new CG schemes to stabilize the CG process and thus to accelerate the CG heuristics. Solving CG subproblems with matheuristics allows to diversify the column generation. Furthermore, a tabu search matheuristic allows to generate aggressively columns at each iteration. Both techniques imply a better stability of the CG scheme: the diversification is interesting for the first iterations whereas tabu intensification is especially useful for the last iterations. It implies a significant acceleration of the CG convergence. A perspective of these CG strategies proposed is an extension to other problems where CG induces independent and heterogeneous subprob-lems

Maintenance planning on French military aircraft operations

The Military Flight and Maintenance Planning Problem considered here aims to assign missions and maintenance tasks to military aircraft. It is a variant of the Flight and Maintenance Planning problem where flights are not modeled geographically since a round-trip to the base is assumed for each flight. It also includes different objectives and constraints

A new simplified daylight evaluation tool, description and validation against the standard method of EN 17037

A new daylight evaluation tool using a simplified assessment method to determine the daylight quantity provided to a typical room was developed. Its calculation method is based on a set of formulas integrating the main factors characterizing the indoor space and the outdoor context. The results are expressed as a corrected Glass-to-Floor ratio (GFR*) which is used as a proxy for the daylight provision. This value can then be used to attribute a rating or “Daylight score” to each space. The main finding is that the simplified method is an easy and relatively reliable estimation for daylight provision. A comparison of the tool with detailed daylight simulations according to the daylight factor method of EN 17037:2018 shows that a high correlation is obtained. The tool is applicable for any case which has conditions matching closely to the models and situations defined. Due to its easy implementation and the limited number of input parameters this evaluation method could be well suited for building passport schemes.publishedVersio

Author name extraction in blog web pages: a machine learning approach

International audienceThis paper presents research results concerning the automatic extraction of author names that are explicitly mentioned in blog web pages. It shows that some NLP pre-preprocessing stages (NE recognition, coreference resolution) prior to a SVM classification have a positive impact on accuracy.Cet article présente les résultats de travaux ayant pour but l'extraction automatique de noms d'auteurs explicites dans des articles de blogs. Il montre que l'ajout de pré-traitements relevant du TAL (détection d'entités nommées, résolution des coréférences) avant une classification de type SVM améliore les performances