In this paper, we prove the applicability of the strong stability method to inventory models. Real life inventory problems are often very complicated and they are resolved only through approximations. Therefore, it is very important to justify these approximations and to estimate the resultant error. We study the strong stability in a periodic review inventory model with an (R, s, S) policy. Af...

In this section is presented the stochastic SIS epidemic model for a closed environment. The order of exposition is the following: firstly is presented the deterministic SI epidemic model, secondly is presented the stochastic SI epidemic model, thirdly is presented the deterministic SIS epidemic model and finally is presented the stochastic SIS epidemic model. All these epidemic models are form...

Abstract Leptophobic Z ′ gauge boson appears naturally in many grand unified theories, such as flipped SU(5) or string-inspired E6 models. This elusive particle easily escapes the direct/indirect detections because it does not couple to charged leptons. However, it can generate flavor changing neutral current at tree level. In this letter, we show that the recently measured mass difference, ∆ms...

the aim of this study was to determine the optimal cutting cycle in an uneven-aged beech forest in the north of iran. first of all, a logistic growth model was determined for an uneven aged forest. then, the stumpage price was predicted via an autoregressive model. the average stumpage price of beech was derived from actual timber, round wood, fire and pulpwood prices at road side minus the var...