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frTue, 13 Jun 2017 07:57:37 +0200https://cedric.cnam.fr/index.php/publis/article/view?id=4052
https://cedric.cnam.fr/index.php/publis/article/view?id=4052
How to Take into Account Uncertainty in Species Extinction Probabilities for Phylogenetic Conservation PrioritizationIn this article we are concerned with the general problem of choosing from a set of taxa T a subset S to protect in order to try to contribute to halting biodiversity loss as efficiently as possible given limited resources. The protection of a taxon decreases its extinction probability and the impact of protecting the taxa of S is measured by the resulting expected phylogenetic diversity (ePD) of the set T. The primary challenge posed by this approach lies in determining the extinction probability of a taxon (protected or unprotected). To deal with this difficulty, the uncertainty about the extinction probabilities can be described through a set of possible scenarios, each corresponding to different extinction probabilities values for each taxon. We show how to determine an “optimal robust set” of taxa to protect, defined as the set of taxa that minimizes the maximum “regret”, i.e. the maximum relative gap, over all the scenarios, between 1) the ePD of T obtained by protecting the taxa of this set and 2) the ePD of T which would be produced by protecting the subset of taxa optimal for the considered scenario. In our experimental conditions covering one hundred cases, this gap is almost always less than 1%. Consequently, the ePD of T obtained by protecting the taxa of the optimal robust set is not far from the maximum ePD of T that could have been obtained if we had known the true scenario. In other words, a way of escaping (in large part, at least) from the uncertainty related to the extinction probabilities of the taxa consists of choosing to protect those belonging to the optimal robust set. We also compare the optimal robust set to other relevant subsets of T.
Tue, 13 Jun 2017 07:57:37 +0200OCPaperhttp://cedric.cnam.fr/index.php/publis/article/view?id=4044
http://cedric.cnam.fr/index.php/publis/article/view?id=4044
Reconstruction of Nearly Convex Colored ImagesThis paper studies the problem of reconstructing hv-convex images with a small
number of discrete colors from two projections for each color in horizontal and vertical
directions. A new integer programming based method is proposed to reconstruct nearly hv-
convex colored images. Firstly, we model the reconstruction problem by a quadratic binary
program. Secondly, we linearize the program into two linear binary programs. Thirdly, we
solve the continuous relaxation of these programs by using IBM ILOG Cplex.Mon, 05 Jun 2017 10:43:16 +0200OCPaperhttp://cedric.cnam.fr/index.php/publis/article/view?id=4043
http://cedric.cnam.fr/index.php/publis/article/view?id=4043
A Greedy Algorithm for Reconstructing Binary Matrices with Adjacent 1sThis paper deals with the reconstruction of special cases of binary matrices with
adjacent 1s. Each element is horizontally adjacent to at least another element. The
projections are the number of elements on each row and column. We give a greedy
polynomial time algorithm to reconstruct such matrices when satisfying only the vertical
projection. We show also that the reconstruction is NP-complete when fixing the number of
sequence of length two and three per row and column.Mon, 05 Jun 2017 10:40:51 +0200OCPaperhttps://cedric.cnam.fr/index.php/publis/article/view?id=4039
https://cedric.cnam.fr/index.php/publis/article/view?id=4039
Daily River Flow Prediction Coupled with Data Processing Techniques: A Comparative Study between Constructive Fuzzy Systems and Autoregressive ModelsDaily river flow forecast is an essential step for real-time hydro-power reservoir operation. The purpose of the flow forecast is to assist in the decision-making process in order to ensure optimal
and reliable operational policy. The paper presents, in a region where meteorological and hydrological data are insufficient, inaccessible and sometimes unreliable, a data-driven model based on Constructive Fuzzy Systems. The model is capable of exploiting the available data with high prediction efficiency was compared to an Autoregressive method. A case study was applied to Litani River in the Bekaa Valley - Lebanon using 4 years of rainfall, temperature, and river flow daily measurements. A reference Auto-Regressive (AR) model, a classical Constructive Fuzzy System Modeling (C-FSM) and the Constructive Fuzzy System Modeling coupled with Moving Average (C-FSM_MA) filter are trained. Upon testing, the last two models have shown primarily competitive performance and accuracy with the ability to preserve the day-to-day variability up to 12 days ahead. In fact, for the longest lead period, the models AR, C-FSM and C-FSM_MA were able of explaining respectively 75%, 79.5% and 84.3% of the actual river flow variation. These results indicate that Moving Average (MA) filter provides a supportive pre-processing tool in the process of streamflow forecasting.
Fri, 02 Jun 2017 18:08:28 +0200OCPaperhttps://cedric.cnam.fr/index.php/publis/article/view?id=4032
https://cedric.cnam.fr/index.php/publis/article/view?id=4032
Reducing the Chromatic Number by Vertex or Edge DeletionsA vertex or edge in a graph is critical if its deletion reduces the chromatic number of the graph by~1.
A graph is vertex-critical if every vertex is critical and edge-critical if every edge is critical.
To increase our understanding of the graph coloring problem, vertex-critical and edge-critical graphs have been studied intensively. We consider the problems of testing whether a graph has a critical vertex or edge, respectively.
We give a complete classification of the complexity of both problems for $H$-free graphs, that is, graphs with no induced subgraph isomorphic to $H$. Moreover, we show that an edge is critical if and only if its contraction reduces the chromatic number by~1.
Hence, we obtain the same classification for the problem of testing if a graph has an edge whose contraction reduces
the chromatic number by~1.
As a consequence of our results, we are also able to complete the complexity classification of the more general vertex deletion and edge contraction blocker problems for $H$-free graphs
when the graph parameter is the chromatic number.
Tue, 30 May 2017 09:53:21 +0200OCPaperhttps://cedric.cnam.fr/index.php/publis/article/view?id=3967
https://cedric.cnam.fr/index.php/publis/article/view?id=3967
Résumé: Logiciel de résolution Logiciel qui résout des programmes quadratiques généraux ayant des variables entières ou réelle et des fonctions quadratiques non convexes. http://cedric.cnam.fr/~lamberta/smiqp/smiqp.php Mises a jour régulières qui suivent les publications [BEL12,BEL13,BEL14,BEL16,BEL16a]. Licence libre.
SMIQP (Solution of Mixed Integer Quadratic Programs). version 2Logiciel de résolution Logiciel qui résout des programmes quadratiques généraux ayant des variables entières ou réelle et des fonctions quadratiques non convexes. http://cedric.cnam.fr/~lamberta/smiqp/smiqp.php
Publications liées [BEL13,BEL14,BEL16,BEL16a]. Licence libre.Wed, 10 May 2017 10:38:37 +0200OCPaperhttps://cedric.cnam.fr/index.php/publis/article/view?id=3966
https://cedric.cnam.fr/index.php/publis/article/view?id=3966
SMIQP (Solution of Mixed Integer Quadratic Programs)Logiciel de résolution Logiciel qui résout des programmes quadratiques généraux ayant des variables entières ou réelle et des fonctions quadratiques non convexes.
http://cedric.cnam.fr/~lamberta/smiqp/smiqp.php
Mises a jour régulières qui suivent les publications [BEL12,BEL13,BEL14,BEL16,BEL16a]. Licence libre.Wed, 10 May 2017 09:54:36 +0200OCPaperhttps://cedric.cnam.fr/index.php/publis/article/view?id=3964
https://cedric.cnam.fr/index.php/publis/article/view?id=3964
Logiciel "Integer Ray Method"Logiciel pour résoudre des programmes de type « génération de colonnes » comme par exemple l'Arc-Routing et le Cutting-Stock (http://cedric.cnam.fr/~porumbed/irm/)Tue, 09 May 2017 15:59:42 +0200OCPaperhttps://cedric.cnam.fr/index.php/publis/article/view?id=3963
https://cedric.cnam.fr/index.php/publis/article/view?id=3963
Bilevel model for adaptive network flow problemTue, 09 May 2017 11:07:21 +0200OCPaperhttps://cedric.cnam.fr/index.php/publis/article/view?id=3962
https://cedric.cnam.fr/index.php/publis/article/view?id=3962
The power edge set problemThe automated real time control of an electrical network is achieved through the estimation of its state using phasor measurement units. Given an undirected graph representing the network, we study the problem of finding the minimum number of phasor measurement units to place on the edges such that the graph is fully observed. This problem is also known as the Power Edge Set problem, a variant of the Power Dominating Set problem. It is naturally modeled using an iteration-indexed binary linear program, whose size turns out to be too large for practical purposes. We use a fixed-point argument to remove the iteration indices and obtain a more compact bilevel formulation. We then reformulate the latter to a single-level mixed-integer linear program, which performs better than the natural formulation. Lastly, we provide an algorithm that solves the bilevel program directly and much faster than a commercial solver can solve the previous models. We also discuss robust variants and extensions of the problemTue, 09 May 2017 10:59:17 +0200OCPaperhttps://cedric.cnam.fr/index.php/publis/article/view?id=3961
https://cedric.cnam.fr/index.php/publis/article/view?id=3961
Solving LP using random projectionsA celebrated result of Johnson and Lindenstrauss asserts that, in high enough dimensional spaces, Euclidean distances defined by a finite set of points are approximately preserved when these points are projected to a certain lower dimensional space. We show that the distance from a point to a convex set is another approximate invariant, and leverage this result to approximately solve linear programs with a logarithmic number of rows.Tue, 09 May 2017 10:56:29 +0200OCPaperhttps://cedric.cnam.fr/index.php/publis/article/view?id=3951
https://cedric.cnam.fr/index.php/publis/article/view?id=3951
Comment optimiser le coût d'un parc d'énergies renouvelables ?Les outils de la recherche opérationnelle pour les énergies renouvelables.Fri, 05 May 2017 11:01:20 +0200OCPaperhttps://cedric.cnam.fr/index.php/publis/article/view?id=3950
https://cedric.cnam.fr/index.php/publis/article/view?id=3950
Un algorithme pour améliorer la production d’électricité renouvelable.Comment tenir compte de l'incertitude des données pour concevoir le design d'un parc mixte de production d'énergies renouvelables.Fri, 05 May 2017 10:28:31 +0200OCPaperhttps://cedric.cnam.fr/index.php/publis/article/view?id=3948
https://cedric.cnam.fr/index.php/publis/article/view?id=3948
TIPE 2014. Transfert, réseaux et graphes.Conférence préparatoires aux TIPE auprès des professeurs des classes préparatoires aux concours d'accès aux grandes écoles d'ingénieur.Fri, 05 May 2017 10:16:42 +0200OCPaperhttps://cedric.cnam.fr/index.php/publis/article/view?id=3942
https://cedric.cnam.fr/index.php/publis/article/view?id=3942
A Recourse Approach for the Capacitated
Vehicle Routing Problem with Evidential
DemandsThe capacitated vehicle routing problem with stochastic de-
mands can be modelled using either the chance-constrained approach or
the recourse approach. In previous works, we extended the former ap-
proach to address the case where uncertainty on customer demands is
represented by belief functions, that is where customers have so-called
evidential demands. In this paper, we propose an extension of the re-
course approach for this latter case. We also provide a technique that
makes computations tractable for realistic situations. The feasibility of
our approach is then shown by solving instances of this difficult problem
using a metaheuristic algorithm.Thu, 04 May 2017 23:38:33 +0200OCPaperhttps://cedric.cnam.fr/index.php/publis/article/view?id=3941
https://cedric.cnam.fr/index.php/publis/article/view?id=3941
The Capacitated Vehicle Routing Problem with Evidential Demands: A Belief-Constrained Programming ApproachThis paper studies a vehicle routing problem, where vehicles have a limited capacity and customer demands are uncertain and represented by belief functions. More specifically, this problem is formalized using a belief function based extension of the chance-constrained programming approach, which is a classical modeling of stochastic mathematical programs. In addition, it is shown how the optimal solution cost is influenced by some important parameters involved in the model. Finally, some instances of this difficult problem are solved using a simulated annealing metaheuristic, demonstrating the feasibility of the approach.Thu, 04 May 2017 23:29:01 +0200OCPaperhttps://cedric.cnam.fr/index.php/default/event/view?id=264
https://cedric.cnam.fr/index.php/default/event/view?id=264
ECCO XXVI conferenceThe ECCO XXVI conference will be organized jointly by the LAMSADE - CNRS UMR 7243 of the University Paris-Dauphine and the laboratory CEDRIC of the Conservatoire National des Arts et M& #233;tiers (CNAM). It will take place in Paris, France. More than 120 participants will attend the conference.
& #160;Tue, 02 May 2017 15:16:05 +0200OCEventhttps://cedric.cnam.fr/index.php/default/event/view?id=263
https://cedric.cnam.fr/index.php/default/event/view?id=263
JFRO "Structures et Algorithmique dans les graphes"Le programme de la journ& #233;e est disponible & #224; l'URL suivante :
http://www.lamsade.dauphine.fr/~jfro/JourneesPrecedentes/anciennesJournees/jfro29.html
& #160;Tue, 02 May 2017 15:08:45 +0200OCEventhttps://cedric.cnam.fr/index.php/default/event/view?id=262
https://cedric.cnam.fr/index.php/default/event/view?id=262
JFRO "Problmes de lot-sizing"Le programme de la journ& #233;e est disponible & #224; l'URL suivante :
http://www.lamsade.dauphine.fr/~jfro/JourneesPrecedentes/anciennesJournees/jfro28.htmlTue, 02 May 2017 15:06:42 +0200OCEventhttps://cedric.cnam.fr/index.php/default/event/view?id=261
https://cedric.cnam.fr/index.php/default/event/view?id=261
JFRO Algorithmes faiblement exponentiels et FPTTue, 02 May 2017 15:00:28 +0200OCEventhttps://cedric.cnam.fr/index.php/default/event/view?id=260
https://cedric.cnam.fr/index.php/default/event/view?id=260
JFRO Problmes de tournes& #160;Le programme de la journ& #233;e est disponible & #224; l'URL suivante :
& #160;
http://www.lamsade.dauphine.fr/~jfro/JourneesPrecedentes/anciennesJournees/jfro26.html
& #160;Tue, 02 May 2017 14:57:10 +0200OCEventhttps://cedric/index.php/default/event/view?id=259
https://cedric/index.php/default/event/view?id=259
Robustesse http://www.lamsade.dauphine.fr/~jfro/Tue, 02 May 2017 12:10:38 +0200OCEventhttps://cedric.cnam.fr/index.php/publis/article/view?id=3935
https://cedric.cnam.fr/index.php/publis/article/view?id=3935
d Behiri and Sana Berraf
Mutualisation de taxis avec partage de coût : complexité paramétrée et heuristique par un problème de stables Tue, 02 May 2017 09:30:01 +0200OCPaperhttps://cedric.cnam.fr/index.php/publis/article/view?id=3933
https://cedric.cnam.fr/index.php/publis/article/view?id=3933
Estimating Daily Evaporation from Poorly – Monitored Lakes using limited Meteorological DataMon, 01 May 2017 09:24:41 +0200OCPaperhttps://cedric.cnam.fr/index.php/publis/article/view?id=3932
https://cedric.cnam.fr/index.php/publis/article/view?id=3932
Estimating Daily Evaporation from Poorly – Monitored Lakes using limited Meteorological DataMon, 01 May 2017 09:24:28 +0200OCPaperhttps://cedric.cnam.fr/index.php/publis/article/view?id=3931
https://cedric.cnam.fr/index.php/publis/article/view?id=3931
Optimization of Wireless Sensor Networks deployment with coverage and connectivity constraintsWireless sensor networks have been widely deployed in the last decades to provide various services, like environmental monitoring or object tracking. Such a network is composed of a set of sensor nodes which are used to sense and transmit collected information to a base station. To achieve this goal, two properties have to be guaranteed: (i) the sensor nodes must be placed such that all the environment of interest is covered, and (ii) every sensor node can transmit its data to the base station (through other sensor nodes). In this paper, we consider the Minimum Connected Coverage (MCC) problem. We propose two mathematical programming formulations for the MCC problem on square grid graphs. We compare them to a recent model proposed by (Rebai et al, 2015). Our mathematical programming formulations yield a better LP-bound at the root of the branch-and-cut process than the model of Rebai et al. Moreover, the presented formulations outperform the proportion of solved instances in their work as well as the CPU computation time and the number of nodes explored in the tree search.Fri, 28 Apr 2017 21:56:48 +0200OCPaperhttps://cedric.cnam.fr/index.php/publis/article/view?id=3930
https://cedric.cnam.fr/index.php/publis/article/view?id=3930
Optimization and simulation for robust railway rolling-stock planning In this paper, we focus on the problem of robust rolling-stock planning for French passenger trains. First, we characterize robustness and define some indicators for the evaluation of rolling-stock rosters. We take a particular interest in homogenizing turning-times in a roster in order to absorb potential delays. Then, we propose a new approach to solve the problem of robust rolling-stock planning. The SNCF reference tool (PRESTO) calculates a solution to the rolling-stock planning problem. It consists of a multi-step approach to cover demand while minimizing operating costs, and to further add maintenance slots to the roster. We propose an integrated ILP model to add robustness to a roster while maintaining low operating costs compared to PRESTO. We have carried out tests on nine real French regional transport instances, and we use a simulation module to evaluate the results. We observe a significant improvement in robustness indicators while maintaining low operating costs and meeting maintenance requirements.Fri, 28 Apr 2017 21:38:09 +0200OCPaperhttp://cedric.cnam.fr/index.php/publis/article/view?id=3919
http://cedric.cnam.fr/index.php/publis/article/view?id=3919
Prize-Collecting Set Multi-Covering With Submodular PricingWe use the theory of submodular function minimization to solve a Column Generation program in which the columns' objective function coefficients are given by a submodular function.Tue, 04 Apr 2017 16:59:22 +0200OCPaperhttps://cedric.cnam.fr/index.php/publis/article/view?id=3904
https://cedric.cnam.fr/index.php/publis/article/view?id=3904
Reformulation and solution approach for non-separable integer quadratic programsWe consider quadratic programs with pure general integer variables. The objective function is quadratic and convex and the constraints are linear. An exact solution approach is proposed. It is decomposed into two phases. In the first phase, the initial problem is reformulated into an equivalent problem with a separable objective function. This is done by use of a Gauss decomposition of the Hessian matrix of the initial problem and requires the addition of some continuous variables and constraints. In the second phase, the reformulated problem is linearized by an approximation of each squared term by a set of K linear functions that correspond to the tangents of a hyperbola in K points. We give a proof of the intuitive property that when K is large enough, the optimal value of the obtained linear program is very close to optimal value of the two previous problems, the initial problem and the reformulated separable problem. The reminder is dedicated to the implementation of a branch-and-bound algorithm for the solution of linearized problem, and its application to a set of instances. Several points are considered among which choice of the right value for parameter K and the implementation of a sophisticated heuristic solution algorithm. The numerical comparison is done with CPLEX 12.2 since, in this case, the initial problem as well as the problem reformulated by the first step can be solved by CPLEX. We show that with our approach, the total CPU time is divided by a factor ranging from 1.2 to 131.6 for instances with 40–60 variables.Fri, 10 Mar 2017 17:33:41 +0100OCPaperhttps://cedric.cnam.fr/index.php/labo/membre/colombier
https://cedric.cnam.fr/index.php/labo/membre/colombier
Kevin ColombieraWed, 01 Mar 2017 15:52:27 +0100OCJob