Mines ParisTech

About: Mines ParisTech is a education organization based out in Paris, France. It is known for research contribution in the topics: Finite element method & Microstructure. The organization has 6564 authors who have published 11676 publications receiving 359898 citations. The organization is also known as: École nationale supérieure des mines de Paris & École des mines de Paris.

One-way carsharing’s evolution and operator perspectives from the Americas

Abstract: Roundtrip carsharing has been documented as a strategy to reduce car ownership and vehicle miles/kilometers traveled in urban areas. The expansion of carsharing and other forms of shared-use mobility have led to a growing interest in understanding the latest models. In recent years, one-way carsharing has gained momentum across the globe with 18 operators providing services in ten countries worldwide. One-way carsharing does not require its users to return the vehicle to the same location from which it was accessed (in contrast to roundtrip carsharing). Users typically pay by the minute versus the hour and do not require a reservation. There are two one-way models: free-floating and station-based. Free-floating carsharing allows vehicles to be picked up and left anywhere within a designated operating area, while station-based requires users to return vehicles to an available station. In Fall 2013, the authors conducted a survey of 26 roundtrip and five one-way carsharing operators in the Americas (U.S., Canada, Mexico, and Brazil) to understand their perspectives on one-way carsharing and its future. Almost 70 % of roundtrip operators viewed one-way carsharing as a complement to roundtrip carsharing, while 19 % viewed it as a competitor. Twelve percent perceived it as both a complement and competitor. Operators noted public transit, smartcard, and electric vehicle integration as key to this model’s expansion. Half of respondents believed one-way and roundtrip carsharing have similar social and environmental impacts. Given limited understanding of its impacts, more research is needed to document the benefits of one-way carsharing and to help inform policymaking and urban mobility.

Mechanics of generalized continua: construction by homogenizaton

Abstract: La mecanique des milieux continus generalises fournit des outils pour decrire les effets d'echelle que presentent certains materiaux heterogenes. Cependant les liens entre les nouveaux degres de liberte que certains de ces milieux introduisent et la microstructure ne sont clairement etablis que pour quelques cas extremes (cristaux liquides...). Dans ce travail, on essaie de construire un milieu de Cosserat homogene equivalent a un milieu classique micro-heterogene, par des methodes d'homogeneisation generalisees. Ces techniques permettent alors de rendre compte des champs de contraintes et de deformation dans un materiau heterogene sollicite de telle sorte que la taille de l'element de volume representatif ne soit pas negligeable devant la longueur d'onde des sollicitations.