the problem of designing a set of routes with minimum cost to serve a collection of customers with a fleet of vehicles is a fundamental challenge when the number of customers to be dropped or picked up is not known during the planning horizon. the purpose of this paper is to develop a vehicle routing problem (vrp) model that addresses stochastic simultaneous pickup and delivery in the urban pub...

this study was designed to assess the frequency of exclusive breastfeeding in two health centers of shahid beheshti university of medical sciences in khak sefid, tehran, iran. a total of 175 mothers, referred for the third dose of their infants' dpt vaccination program participated in the study by completing a questionnaire regarding characteristics of their pregnancy, delivery and exclusive br...

abstract background: labor is a physiologic process, and consideration of labor pain and relieving that is among the major components of maternal care. application of some labor position can lay the fetus better in pelvic canal direction. the present study aimed to investigate the effect of laying the mother in three labor positions on the pain severity in the second, third, and fourth stages o...

in this paper we address the vrpcd, in which a set of homogeneous vehicles are used to transport products from the suppliers to customers via a cross-dock. the products can be consolidated at the cross-dock but cannot be stored for very long as the cross-dock does not have long-term inventory-holding capabilities. the objective of the vrpcd is to minimize the total traveled distance while respe...

since its original conception in 1959, by nobel physicist richard p feynman, the notion of nanotechnology and its potential ramifications have not only created fascination,but also intense scientific efforts and scrutiny. one of the most promising applications of nanotechnology is in the context of medicine. due to their unique size-dependent properties nanomaterials such as nanoparticles offer...

abstractgene therapy is a therapeutic approach to deliver genetic material into cells to alter their function in entire organism. one promising form of gene delivery system (dds) is liposomes. the success of liposome-mediated gene delivery is a multifactorial issue and well-designed liposomal systems might lead to optimized gene transfection particularly in vivo. liposomal gene delivery systems...

training is considered an important element in the organization, as it heavily influences people to learn how to be more effective at work by modifying knowledge, skills or attitudes through the learning experience to achieve a successful performance. likewise, training is a long term allegiance to all employees because they have to learn new skills and knowledge which become a turning point fo...

the vehicle routing problem with simultaneous pickup and delivery (vrpspd) is a well-known combinatorial optimization problem which addresses provided service to a set of customers using a homogeneous fleet of capacitated vehicles. the objective is to minimize the distance traveled. the vrpspd is an np-hard combinatorial optimization problem. therefore, practical large-scale instances of vrpspd...