EXPERIMENTAL EVIDENCE FOR TWO KINDS OF DEFECTS IN AMORPHOUS Fe80 B20

The scattering of cold neutrons (λ = 1 nm) with amorphous Fe80 11B20 yields a strong contribution at small q=4π (0.7 (nm)-1 ≤ q ≤ 2.4 (nm)-1 arising from two kinds of defects of different size : i) local defects with an extent of about 1.5 nm ii) Extended defects with an extent of about 40 to 60 nm, which are interpreted as quasi-dislocations in the amorphous material

The Static Bicycle Repositioning Problem - Literature Survey and New Formulation

This paper considers the static bicycle repositioning problem (SBRP), which deals with optimally re-balancing bike sharing systems (BSS) overnight, i.e. using service vehicles to move bikes from (nearly) full stations to (nearly) empty stations. An exhaustive literature survey comparing existing models is presented, and a new and improved mathematical formulation for the SBRP is proposed. The model is tested on a number of instances generated based on data from a real BSS

Shared mobility systems: an updated survey

International audienceTransportation habits have been largely modified in the past decade by the introduction of shared mobility systems. These have been a partial response to the need of resorting to green means of transportation and to the desire of being more flexible in the choice of trips, both from a spatial and temporal point of view. On the one hand, shared mobility systems have taken advantage of the interest for shared experiences. On the other hand, their success has been possible as a result of the recent advances in information and communications technology. The operational research community is already very active in this emerging field, which provides a very rich source of new and interesting challenges, covering several planning levels, from strategic to operational ones, such as station location, station sizing, rebalancing routes. A fascinating feature of this field is the variety of the methods used to deal with these questions. Our purpose is to survey the main problems and methods arising in this field. Bicycle and car sharing and Fleet dimensioning and Inventory rebalancing and Shared mobility systems and Survey and Vehicle repositionin