Decisions with conflicting and imprecise information

The most usual procedure when facing decisions in complex settings consists in consulting experts, aggregating the information they provide, and deciding on the basis of this aggregated information. We argue that such a procedure entails a substantial loss, insofar as it precludes the possibility to take into account simultaneously the decision maker's attitude towards conflict among experts and her attitude towards imprecision of information. We propose to consider directly how a decision maker behaves when using information coming from several sources. We give an axiomatic foundation for a decision criterion that allows to distinguish on a behavioral basis the decision maker's attitude towards imprecision and towards conflict.Decisions with multiple sources of information. Conflict aversion. Imprecision aversion.

Morphological characterization of a polymeric microfiltration membrane by synchrotron radiation computed microtomography

Most commercial polymeric membranes are prepared by phase inversion. The performance of the membranes depends greatly on the morphology of the porous structure formed during the different steps of this process. Researchers in this field have found it extremely difficult to foresee how a change in the composition of the polymer solution will affect pore formation without a set of methods designed to yield detailed knowledge of the morphological structure. This paper reports the new potential associated with X-Ray synchrotron microtomography to characterize the 3D structure of a PvDF hollow fibre microfiltration membrane prepared by phase inversion. 3D morphological data obtained from the ID19 line at the ESRF are presented. The membrane actually appears as a complex three-dimensional bi-continuum of interconnected pores. Within the hollow fibre structure, different regions with various thicknesses and pore size distributions have been identified and well characterized. Transversal views show the anisotropic finger-like structure of pores, while longitudinal sections reveal a honeycomb structure which resembles the structure of highly concentrated water in oil emulsion or dispersion. This typical structure might be obtained during the phase inversion process. How the phase inversion process may result in these morphologies is finally discussed

Representation and aggregation of preferences under uncertainty

We axiomatize in the Anscombe–Aumann setting a wide class of preferences called rank-dependent additive preferences that includes most known models of decision under uncertainty as well as state dependent versions of these models. We prove that aggregation is possible and necessarily linear if and only if (society's) preferences are uncertainty neutral. The latter means that society cannot have a non-neutral attitude toward uncertainty on a subclass of acts. A corollary to our theorem is that it is not possible to aggregate multiple prior agents, even when they all have the same set of priors. A number of ways to restore the possibility of aggregation are then discussed.Aggregation; Uncertainty

On the impossibility of preference aggregation under uncertainty

We provide a general theorem on the aggregation of preferences under uncertainty. We study, in the Anscombe-Aumann setting a wide class of preferences, that includes most known models of decision under uncertainty (and state-dependent versions of these models). We prove that aggregation is possible and necessarily linear if (society's) preferences are "smooth". The latter means that society cannot have a non-neutral attitude towards uncertainty on a subclass of acts. A corollary to our theorem is that it is not possible to aggregate maxmin expected utility maximizers, even when they all have the same set of priors. We show that dropping a weak notion of monotonicity on society's preferences allows one to restore the possibility of aggregation of non-smooth preferences.Aggregation, Harsanyi, uncertainty, multiple priors.

Decision Making with Imprecise Probabilistic Information

We develop an axiomatic approach to decision under uncertainty that explicitly takes into account the information available to the decision maker. The information is described by a set of priors and a reference prior. We define a notion of imprecision for this informational setting and show that a decision maker who is averse to information imprecision maximizes the minimum expected utility computed with respect to a subset of the set of initially given priors. The extent to which this set is reduced can be seen as a measure of imprecision aversion. This approach thus allows a lot of flexibility in modelling the decision maker attitude towards imprecision. In contrast, applyingGilboa-Schmeidler [1989] maxmin criterion to the initial set of priors amounts to assuming extreme pessimism.Uncertainty, Decision, Multiple Priors

Decision Making with Imprecise Probabilistic Information.

We develop an axiomatic approach to decision under uncertainty that explicitly takes into account the information available to the decision maker. The information is described by a set of priors and a reference prior. We define a notion of imprecision for this informational setting and show that a decision maker who is averse to information imprecision maximizes the minimum expected utility computed with respect to a subset of the set of initially given priors. The extent to which this set is reduced can be seen as a measure of imprecision aversion. This approach thus allows a lot of flexibility in modelling the decision maker attitude towards imprecision. In contrast, applying Gilboa and Schmeidler (1989) maxmin criterion to the initial set of priors amounts to assuming extreme pessimism.Uncertainty; Decision; Multiple Priors

PROJETS DE TERRITOIRES ET OBSERVATION DES AGGLOMERATIONS : REFLEXIONS A PARTIR DES CAS DE TOURS ET D'ORLEANS

Tours et Orléans comptent parmi les aires urbaines françaises qui ont connu, au cours des années 1990, un fort accroissement de leur population. D'Orléans à Nantes, la vallée de la Loire présente le double avantage d'être proche d'une des régions européennes les plus dynamiques - l'Ile de France - et d'être bien équipée en infrastructures autoroutières et ferrées. Les agglomérations d'Orléans et de Tours font donc partie des espaces français attractifs pour les activités économiques et les ménages en quête de localisation. Pourtant, comparées à d'autres villes françaises ou étrangères, Orléans et Tours ne sont absolument pas des métropoles. Quelles actions publiques pourraient permettre éventuellement de faire évoluer ces deux agglomérations vers un statut métropolitain ? Il s'agit à la fois d'un problème de développement urbain et d'aménagement régional - voire interrégional. D'un côté, l'analyse de différents exercices de planification du développement dans ces deux agglomérations permet de mettre en évidence une faible appréhension du phénomène métropolitain par les acteurs locaux, ainsi qu'une absence de lien entre la connaissance d'un territoire et les projets qui y sont mis en oeuvre. De l'autre, dans la mesure où ces deux agglomérations se situent dans la même région - la région Centre - et sont de taille équivalente, ne faut-il pas envisager leur évolution non seulement de façon séparée, mais aussi dans une possible mise en réseau, permettant de faire émerger une aire métropolitaine intermédiaire entre l'Ile de France, Nantes et Bordeaux ? Dans le cadre de cette communication, c'est surtout la première question qui nous intéresse. Après avoir rappelé les éléments principaux qui caractérisent la région Centre et tout particulièrement son espace ligérien, nous verrons à la lumière de l'examen d'un ensemble de diagnostics urbains, liés à quelques exercices récents de planification, que les conditions de l'émergence d'un processus de métropolisation sont loin d'être réunies

Electrical properties and non-volatile memory effect of the [Fe(HB(pz)3)2] spin crossover complex integrated in a microelectrode device

We report on the deposition of thin films of the [Fe(HB(pz)3)2] (pz = pyrazolyl) molecular spin crossover complex by thermal evaporation. By means of impedance measurements and Raman microspectroscopy, we show that the films maintain the structure and properties of the bulk material. The conductivity of the films decreases by ca. 2 orders of magnitude when the freshly deposited compound goes through a first (irreversible) thermal phase change above ca. 380 K. This property can be exploited as a non-volatile (read-only) memory effect