An integrated model considers all parameters and elements of different deficiencies in one problem. This paper presents a new integrated model of a supply chain that simultaneously considers facility location, vehicle routing and inventory control problems as well as their interactions in one problem, called location-routing-inventory (LRI) problem. This model also considers stochastic demands ...

We consider an M/G/1 retrial queue with general retrial times and single working vacation. During the working vacation period, customers can be served at a lower rate. Both service times in a vacation period and in a service period are generally distributed random variables. Using supplementary variable method we obtain the probability generating function for the number of customers and the ave...

This paper studies the effects of psychological, individual, product strategy, and situational factors on the impulse purchase behavior of customers in all Refah stores located in Tehran. The paper uses Betty and Ferrell Model to set forward and to test 4 hypothesis. All four hypothesis were confirmed. The results indicated that the selected factors had impact on the impulse behavior of the con...

The present status of the problem of neutrino mass, mixing and neutrino oscillations is briefly summarized. The evidence for oscillations of atmospheric neutrinos found recently in the Super-Kamiokande experiment is discussed together with the results of the solar neutrino experiments and the accelerator LSND experiment.

Historical trends in face perception research during the past half century are summarized. The dual process model offered by cognitive neuroscientists to account for the perception of identity and emotion expression in the face is briefly reviewed together with supporting evidence. An ecological approach that incorporates missing pieces of face perception is offered as an additional, broader co...

In this paper, an M/M/1 queue with working vacation and vacation interruption is investigated. The server is supposed to take a working vacation whenever the system becomes empty and if there are at least N customers waiting in the system at a service completion instant, vacation interruption happens and the server resumes a normal working period. A matrix geometric approach is employed to obta...