Search results for "Operational Research"
showing 10 items of 24 documents
Configuration optimale des aires de marché et coûts de transport
1991
La théorie des Places Centrales étudiée par LÖSCH (4) et CHRISTALLER (5) a pour objet l'examen et la construction d'un paysage hiérarchisé. Celui-ci est basé sur un système d'aires de marché qui possèdent des configurations précises (hexagonales et carrées principalement). En fait raire de marché correspond à la zone d'influence d'un offreur. LÖSCH (4, p 130) a supposé que la libre entrée de firmes indépendantes localisées sur une plaine où sont situés des demandeurs équidistants entraine une transformation des aires circulaires en aires hexagonales et ainsi une maximisation du nombre de firmes par unité d'aire. HARTWICK (2) examine analytiquement le théorème de LÖSCH concernant les aires d…
Appropriateness between physical space and multicentre economic space in localization problems
1991
Location models are constructed in mathematical economic spaces whereas people locate themselves in real or physical spaces. If economic spaces are multicentric ones, their properties are different from physical spaces. We say that these two spaces are not symmetric. Hence, mathematical location model can lead to an optimal location solution which doesn't' exist in physical space. But, if we admit that an optimal location solution owns more or less to a function of demand of location, we can resolve this question. Then, fuzzy demand functions of location are defined in multicentric spaces and an illustration of this concept is presented.
Editorial: Special issue on Simulation in Transportation
2020
Transportation systems and related policies are complex and cross-sectoral, covering different socio-economic and management aspects, and involving multiple stakeholders (such as users, operators, and public policymakers). Mobility and accessibility are central to economic and societal well-being, yet the process of doing so may have significant impacts on land use, environment, and public health. Furthermore, the many feedbacks involved occur at varying degrees of spatial, temporal, and socio-demographic granularity and levels of uncertainty. Simulation models are well established in transportation-related operational research and management science, and the alternative approaches of Syste…
Quasi order, pseudo order and not order
1995
This study, after having presented the structure of total semi-order and that of pseudo-order one, presents a new preference structure called non order. This one generalizes both the semi-order structure and the pseudo-order one. The details analysis are based on the usual concepts of the relationnal approach of preference modelling and on some new concepts and principles which fit the imprecise context. These new principles are : imprecise discriminant power, imprecise transitivity, imprecise intransitivity and generalized limited comparability. The new concepts are : preference relationnal constituent and preference relationnal state.
Recursive estimators 2
1991
In this paper the techniques for recursive estimation of linear model are extended to non-spherical disturbances. First we present the recursive formulae of generalized least squares. The recurrence relation for the residual sum of squares are derived. We show in the second part of the paper a recursive formulae of generalized instrumental variables.
Distribution of power and social utility under nonadditive aggregation rules
1992
In this paper, we try first to shift the problem onto the agents. We want actually to consider some methods for passing from coalitions to lotteries over coalitions. These methods are associated with a function that could correspond to a social utility function. It gives the level of satisfaction coming from the anticipated "consumption" of a subset of alternatives (goods, candidates,..) by a coalition. Second, we want to define the distributions of power regardless of those two-element feasible sets which characterize preferences in basic models on one side, and we try to exhibit a theoretical relation between the basic Barberà & Sonnenschein’s model and ours thanks to the Choice Axiom of …
Mean Field Linear Quadratic Games with Set Up Costs
2013
This paper studies linear quadratic games with set up costs monotonic on the number of active players, namely, players whose action is non-null. Such games arise naturally in joint replenishment inventory systems. Building upon a preliminary analysis of the properties of the best response strategies and Nash equilibria for the given game, the main contribution is the study of the same game under large population. We also analyze the influence of an additional disturbance in the spirit of the literature on H∞ control. Numerical illustrations are provided. © 2012 Springer Science+Business Media New York.
A Computationally Inexpensive Approach in Multiobjective Heat Exchanger Network Synthesis
2010
We consider a heat exchanger network synthesis problem formulated as a multiobjective optimization problem. The Pareto front of this problem is approximated with a new approximation approach and the preferred point on the approximation is found with the interactive multiobjective optimization method NIMBUS. Using the approximation makes the solution process computationally inexpensive. Finally, the preferred outcome on the Pareto front approximation is projected on the actual Pareto front. peerReviewed
Agreement and disagreement between expectations and realizations
1990
The objective of the paper is to measure the intensity of the relation between expectations and realizations for strategic variables of firms, such as production, demand or prices. An anticipation error reveals a disagreement which can be associated with the rational expectations hypothesis. The agreement coefficient between classifications, given by COHEN (1968) and LIGHT (1971) and calculated from a probability matrix, is used to define a direct measure of the disagreement between classifications. Comparison of the coefficients is used to test the rational expectations hypothesis.The coefficients are applied to business survey data of INSEE for France between 1974 and 1986.
Coordination and profit rate maximization
1995
We study the effects over the coordination between firms of the choice of another objectivefunction for the firm: the profit rate maximization which seems to be closer to business practice than the classical pure profit maximization. After recalling the effect of the new objective function over the optimum (the optimal production is lower), two cases are considered : perfect competition (the price signal disappear), and duopoly-oligopoly (the functions of reactions may vanish). (FR) Nous étudions les effets sur la coordination inter-firmes du choix d'une autre fonction objectif pour la firme: la maximisation du taux de profit qui semble être plus proche de la pratique des affaires que la cl…