This paper addresses the vehicle routing problem with simultaneous pickup and delivery (VRPSPD) which is the problem of optimally integrating goods deliver and pickup when there are no precedence restrictions on the order in which the operations must be performed. We review mixed integer programming formulations in the literature for VRPSPD and propose two new formulations, PM1 and PM2, for the...

This paper introduces an integrated approach for solving the Period Vehicle Routing Problem with Simultaneous Delivery and Pickup (PVRPSDP). The problem considers a dis tribution system consisting of a warehouse and many dispersed location retailers, where each of which having two type of demands to be delivered and collected, respectively. A fleet of capacitated vehicle is employed for deliver...

[1] We report a newly created highly parallelized global test particle model for resolving the pickup oxygen ion distribution around Mars. The background magnetic and convection electric fields are calculated using a three-dimensional multispecies magnetohydrodynamic model, which includes the effect of the Martian crustal magnetic field. In addition to photo-ionization, charge exchange collisio...

As we progress towards a world where robots play an integral role in society, a critical problem that remains to be solved is the Pickup Team Challenge; that is, dynamically formed heterogeneous robot teams executing coordinated tasks where little information is known a priori about the tasks, the robots, and the environments in which they will operate. Successful solutions to forming pickup te...

In this paper, we consider vehicle routing problems with backhauls and time windows (VRPBTW). Different backhaul variants are studied, namely clustered backhauls (CB), mixed linehauls and backhauls, and variants with simultaneous delivery and pickup and with divisible delivery and pickup. Three dimensional loading constraints are assumed. A two-phase approach following the principle packing fir...

This paper addresses the Electric Vehicle Routing Problem with Simultaneous Pickup and Delivery (EVRP-SPD), in which electric vehicles (EVs) simultaneously deliver goods to pick up from customers. Due limited battery capacity of EVs, their range is shorter than that internal combustion vehicles. In EVRP, addition depot customers, there are also charging stations (CS) because EVs need be charged...

Previous research has shown that oocyte cumulus complex (OCC) pickup rate is inhibited in hamsters when oviducts and OCCs are simultaneously exposed to cigarette smoke solutions, independent of any effect on ciliary beat frequency. The purpose of this research was to determine whether smoke solutions caused a change in adhesion between the OCC and infundibulum of the oviduct and to determine wh...