Search results for "Operational Research"
showing 10 items of 24 documents
Note on the ranking of fuzzy numbers: conditions for a total order relation
1988
It is well-known that the set of fuzzy numbers is not ordered. The author states the conditions which have to be satisfied so that the problem of ranking fuzzy numbers has a solution. In fact, the subset of fuzzy numbers, the elements of which are strictly defined and continuous,is endowed with a total order relation.
Solving the Problems of Inspection Planning under Parametric Uncertainty of Underlying Models
2013
Certain fatigued structures must be inspected in order to detect fatigue damages that would otherwise not be apparent. A technique for obtaining optimal inspection strategies is proposed for situations where it is difficult to quantify the costs associated with inspections and undetected failure. For fatigued structures for which failures (fatigue damages) are only detected at the time of inspection, it is important to be able to determine the optimal times of inspection. Fewer inspections will lead to lower fatigue reliability of the structure upon demand, and frequent inspection will lead to higher cost. When there is a fatigue reliability requirement, the problem is usually to develop an…
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…
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.
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.
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.
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.
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 …
De l'effet d'imprécision et du paradoxe de la non ponctualité des seuils vers la définition de quelques concepts et principes de modélisation des pré…
1994
(EN) This survey deals with conceptual and theoritical basis of imprecise preference modelling. From the establishment of non-punctuality of the imprecise preference threshold, imprecise discrimination power is set. This involves that the modelling preference relation tool is composite. Which allows a generalization of the limited comparability principle and an introduction of new concepts which adapt to this theoritical framework.(FR) Ce travail pose les fondements conceptuels et théoriques de la modélisation des préférences imprécises. A partir du constat de non ponctualité des seuils de préférence, il pose le principe du pouvoir discriminant imprécis. Il en résulte que l'outil relationne…
Intern conflicts and a production function with combining sub-factors
1994
Considering sub-factors, like different categories of capital or different categories of work, a production function is proposed: each sub-factor of one factor may be combined with each sub-factor of the other factor. Different types of programs exists at different levels. The conditions to obtain identical solution for these programs are studied. Considering that there is one responsible manager by program, conflicts between managers of each program arepossible because these programs give non identical solutions in general. The important fact is that these intern conflicts appear naturally without extra economical considerations