This paper deals with a delayed ratio-dependent functional response predator-prey model with a threshold harvesting policy. We study the equilibria of the system before and after the threshold. We show that the threshold harvesting can improve the undesirable behavior such as nonexistence of interior equilibria. The global analysis of the model as well as boundedness and permanence properties a...

In this paper, we consider a newsvendor who is going to invest on dedicated or flexible capacity, our goal is to find the optimal investment policy to maximize total profit while the newsvendor faces uncertainty in lead time and demand simultaneously. As highlighted in literature, demand is stochastic, while lead time is constant. However, in reality lead time uncertainty decreases newsvendor's...

We consider a discrete-time Markov decision process with a partially ordered state space and two feasible control actions in each state. Our goal is to nd general conditions, which are satissed in a broad class of applications to control of queues, under which an optimal control policy is monotonic. An advantage of our approach is that it easily extends to problems with both information and act...

Under cutoff and threshold priority policies, we mathematically formulate a prioritized channel allocation problem which is combinatorial in nature. We then reduce that problem using the concept of pattern, and apply a simulated annealing approach to the reduced problem. Computational experiments show that our method works very well and the cutoff priority policy outperforms the non-prioritized...

Classic models of cell size control consider that cells divide when reaching a threshold, e.g., size, age, or extension. The molecular basis the threshold involves multiple layers regulation as well gene noise. In this paper, we study cycle first-passage problem with stochastic and discover such stochasticity affects intergeneration statistics, which bewilders criteria to distinguish types mode...

Heterogeneous servers which can differ in service speed and reliability are getting more popular in modelling of modern communication systems. For a two-server queueing system with one non-reliable server and constant retrial discipline we formulate an optimal allocation problem for minimizing a long-run average cost per unit of time. Using a Markov decision process formulation we prove a numbe...

Optimal control problems are applied to a variety of dynamical systems with random law motion. In this paper we show that the degradation processes defined on discrete set intermediate states also suitable for formulating and solving optimization finding an appropriate optimal policy. Two models considered in paper: time instantaneous failure preventive maintenance. both cases, threshold-based ...