24 research outputs found

    Modelling bargaining behaviors within biotech clusters - Towards the "power of the weak" emergence?

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    If spatial and industrial economics theorical models, such as industrial districts, clusters, or learning regions propose a large analysis of differentiated coordination mecanisms, it however not really takes into account behavior of dispute dynamics, such as conflict of bargaining and power, which can explain both diversity and ambivalence of local coordinations. So, our purpose in this contribution is to bring to light that bargaining and power conflicts are at stake in coordinations structuration within territories. We base this contribution on Artificial Life simulations involving public and private local actors who bargain to share a local resource using more or less sophisticated strategies. On a methodologic point of view, our thought is based on an empirical established fact. Analysis of a biotechnology cluster in Toulouse-France (Leroux I., 2002, 2004) indeed contributes to bring to light that coordinations involving pharmaceutical industry, local communities and local research laboratories are based on direct or indirect evolving domination and concession bargaining games. If industrial firms play "the power of the weak" game, making concession of their decision power to public research laboratories, they endeavour systematically to exerce an influence or a discrimination power, by using hided and indirect means that forward by local communities.Starting from this established fact, we propose Artificial Life simulations of local bargaining games, inspired from the T. Ellingsen (1997) bargaining evolutionnary game. This is a Nash demand game under ultimatum. It leads to the interaction of obstinate agents whose demands are independent of those of the adversaries, and sophisticated agents who adapt their demand to that hoped for of their adversaries rather than gain nothing. As a result, our simulations show that bargainings between these local actors lead to an agreement which is not a perfect share, or an "universal" rule, but a compromise frequently hiding complex mecanisms of domination and concession. The main contribution of these simulations, which are based on genetic algorithms, is to put in a prominent position the variations of behavioral rules. We show how bargaining is an evolving processus based on domination and concession behaviors (influence, coercion,…) bringing to light the T. Schelling (1960) "power of the weak". This result brings to the fore the question of flexibility and phasing dynamics of power behaviors in local coordination bargainings. This model can contributes to open new researches focused on power and conflict strategies within local coordinations.

    Optimisation multiobjectif discrète par propagation de contraintes

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    National audienceLa majorité des problèmes réels nécessitent l'optimisation selon des objectifs contradictoires. La solution choisie par un décideur sera un compromis dépendant d'un grand nombre de paramètres variant d'un décideur à un autre et donc difficiles à modéliser. Une méthode automatisée ne pourra pas effectuer un choix parmi toutes les solutions de compromis, mais devra les présenter pour que le décideur effectue le meilleur choix. Les algorithmes sont généralement basés sur des algorithmes génétiques rendant la modélisation et le réglage des paramètres complexes pour une personne pas spécialisée dans le domaine. De plus évaluer la qualité des solutions proposées est difficile. Notre approche permet d'utiliser la facilité de modélisation de la programmation par contraintes et permet l'obtention d'une borne supérieure du problème. Sur un problème à variables discrètes, elle permet d'obtenir le front de Pareto exact

    Intégration Holistique des Graphes basée sur la Programmation Linéaire pour l'Entreposage des Open Data

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    National audienceDans cet article, nous proposons une approche holistique pour l'intégration des graphes d'Open Data. Ces graphes représentent une classification hiérarchique des concepts extraits des Open Data. Nous nous focalisons sur la conservation de hiérarchies strictes lors de l'intégration afin de pouvoir définir un schéma multidimensionnel à partir de ces hiérarchies et entreposer par la suite ces sources de données. Notre approche est basée sur un programme linéaire qui résout automatiquement la tâche de matching des graphes tout en maximisant globalement la somme des similarités entre les concepts. Ce programme est composé de contraintes sur la cardinalité du matching et de contraintes sur la structure des graphes. A notre connaissance, notre approche est la première à fournir une solution optimale globale pour le matching holistique des graphes avec un temps de résolution raisonnable. Nous comparons également la qualité des résultats de notre approche par rapport à d'autres approches de la littérature

    Holistic Statistical Open Data Integration Based On Integer Linear Programming

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    International audienceIntegrating several Statistical Open Data (SOD) tables is a very promising issue. Various analysis scenarios are hidden behind these statistical data, which makes it important to have a holistic view of them. However, as these data are scattered in several tables, it is a slow and costly process to use existing pairwise schema matching approaches to integrate several schemas of the tables. Hence, we need automatic tools that rapidly converge to a holistic integrated view of data and give a good matching quality. In order to accomplish this objective, we propose a new 0-1 linear program, which automatically resolves the problem of holistic OD integration. It performs global optimal solutions maximizing the profit of similarities between OD graphs. The program encompasses different constraints related to graph structures and matching setup, in particular 1:1 matching. It is solved using a standard solver (CPLEX) and experiments show that it can handle several input graphs and good matching quality compared to existing tools

    A Linear Program For Holistic Matching : Assessment on Schema Matching Benchmark

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    International audienceSchema matching is a key task in several applications such as data integration and ontology engineering. All application fields require the matching of several schemes also known as "holistic matching", but the difficulty of the problem spawned much more attention to pairwise schema matching rather than the latter. In this paper, we propose a new approach for holistic matching. We suggest modelling the problem with some techniques borrowed from the combinatorial optimization field. We propose a linear program, named LP4HM, which extends the maximum-weighted graph matching problem with different linear constraints. The latter encompass matching setup constraints, especially cardinality and threshold constraints; and schema structural constraints, especially superclass/subclass and coherence constraints. The matching quality of LP4HM is evaluated on a recent benchmark dedicated to assessing schema matching tools. Experimentations show competitive results compared to other tools, in particular for recall and HSR quality measure

    Graph-Based ETL Processes For Warehousing Statistical Open Data

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    ICEIS 2015 will be held in conjunction with ENASE 2015 and GISTAM 2015International audienceWarehousing is a promising mean to cross and analyse Statistical Open Data (SOD). But extracting structures, integrating and defining multidimensional schema from several scattered and heterogeneous tables in the SOD are major problems challenging the traditional ETL (Extract-Transform-Load) processes. In this paper, we present a three step ETL processes which rely on RDF graphs to meet all these problems. In the first step, we automatically extract tables structures and values using a table anatomy ontology. This phase converts structurally heterogeneous tables into a unified RDF graph representation. The second step performs a holistic integration of several semantically heterogeneous RDF graphs. The optimal integration is performed through an Integer Linear Program (ILP). In the third step, system interacts with users to incrementally transform the integrated RDF graph into a multidimensional schema

    Transformer les Open Data brutes en graphes enrichis en vue d'une intégration dans les systèmes OLAP

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    National audienceThe Open Data integration in the decision systems is challenged by the absence of schema, the raw data and the semantic and structural heterogeneousness. In the literature, the most of authors studies the integration of RDF’Open Data in information systems besides the little percentage of available data in this format. On the other hand, few works are interested of Excel’Open Data despite they represent more than 90% of the available data.In this paper, we provide an automatic process that transforms raw Open Data in exploitable rich graphs. This process is validated by the users. This is part of our generic approach for integrating theOpen Data into multidimensional data warehouse.L’intégration des Open Data dans les systèmes OLAP est difficile en raison de l’absence de schémas sources, l’aspect brut des données et l’hétérogénéité sémantique et structurelle. La plupart des travaux existants s’intéressent aux Open Data de format RDF qui restent actuellement minoritairement disponibles. En revanche, peu de travaux s’intéressent aux Open Data de format brut, par exemple Excel qui représentent pourtant plus que 90% des données ouvertes disponibles. Dans cet article, nous proposons un processus automatique de transformation des Open Data brutes en graphes enrichis exploitables pour l’intégration. Ce processus est validé par l’utilisateur et s’inscrit dans notre démarche d’intégration des Open Data dans les entrepôts de données multidimensionnelles

    REPPlab: An R package for detecting clusters and outliers using exploratory projection pursuit

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    The R-package REPPlab is designed to explore multivariate data sets using one-dimensional unsupervised projection pursuit. It is useful as a preprocessing step to find clusters or as an outlier detection tool for multivariate data. Except from the packages tourr and rggobi, there is no implementation of exploratory projection pursuit tools available in R. REPPlab is an R interface for the Java program EPP-lab that implements four projection indices and three biologically inspired optimization algorithms. It also proposes new tools for plotting and combining the results and specific tools for outlier detection. The functionality of the package is illustrated through some simulations and using some real data

    Algorithmes évolutionnaires pour l’optimisation multi-objectif

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    Nous présentons une synthèse des méthodes d’optimisation multi-objectif à base d’algorithmes évolutionnaires. Les méthodes sont classées en trois catégories : les méthodes agrégées, les méthodes basées sur Pareto et les méthodes non agrégées et non Pareto. Après une introduction théorique, nous présentons les méthodes figurant parmi les plus usitées et les plus originales de chaque catégorie et dont l’apport scientifique est le plus significatif. Nous terminons par une discussion sur la mise en oeuvre de ces méthodes

    Optimisation multiobjectif et stratégies d' évolution en environnement dynamique

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    Après un état de l' art sur les méthodes utilisées pour résoudre des problèmes multiobjectifs et des problèmes en environnement dynamique, nous proposons une méthode multiagent d' optimisation en environnement dynamique qui offre une réponse discriminante à un changement d' environnement. Une généralisation de cette méthode aux problèmes multiobjectifs est également proposée.TOULOUSE1-BU Arsenal (315552103) / SudocSudocFranceF
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