there has been extensive work on the existence of periodic solutions for nonlinear second order autonomous differantial equations, but little work regarding the third order problems. the popular poincare-bendixon theorem applies well to the former but not the latter (see [2] and [3]). we give a necessary condition for the existence of periodic solutions for the third order autonomous systems, t...

This study contributes to the periodic review inventory system literature by: (1) investigating customer service level (CSL) as a social responsibility in pharmaceutical supply chains (PSCs) and (2) proposing chain contracting achieve win–win coordination guarantee satisfied CSL. Specifically, considering demand uncertainty one of main challenges faced by pharmacies, we analyze how applying con...

Using a generalization of Scarf's K-convexity, we are able to show that the optimal policy for the periodic review inventory problem with xed ordering costs and nite capacity has an (s; S)-like structure. In particular, we are able to divide the parameter space into four regions. In two of these regions the optimal policy is completely speci ed. In the other two, it is partially speci ed.

With attention to the thin film structure of colloidal quantum dot solar cells, in this paper in order to improvement of active layer absorption of them, we have proposed the use of nanostructure pattern for enhancement of their performance. For this purpose we have presented suitable nano hemisphare patterns in colloidal quantum dot solar cells for light trapping in absorption layer. Then with...

This paper copes with a joint Location-Allocation-Inventory problem in three-echelon base-level spare part support system epistemic uncertainty uncertain demands of bases. The aim the is to propose an optimization model under theory minimize total cost, which integrates crucial characterizations inventory control decisions and location-allocation scheme arrangement periodic review order-up-to-S...

juvenile nasopharyngeal angiofibroma (jna) is a rare, benign and locally invasive tumor. massive bleeding because of vascularity of tumor and postoperative recurrence are potential problems of management. endonasal approach reduces the rate of postoperative recurrence, intraoperative bleeding, and complications of surgery, time of operation and duration of hospitalization. in this article, we r...

The single-item stochastic inventory control problem is to find an inventory replenishment policy in the presence of independent discrete stochastic demands under periodic review and finite time horizon. In this paper, we prove that this problem is intractable and for any 2 > 0, we design an algorithm with running time polynomial in the size of the problem input and in 1/2, that finds a policy ...

A real-time system must execute functionally correct computations in a timely mannel: In order to guarantee that all tasks accepted in the system will meet their timing requirements, an admission control algorithm must be used to only accept tasks whose requirements can be satisfied. Rate-monotonic scheduling (RMS) is arguably the best known scheduling policy for periodic real-time tasks on uni...