We deal with semi-Markov control models with Borel state and control spaces, and unbounded cost functions under the ratio and the time expected average cost criteria. Under suitable growth conditions on the costs and the mean holding times together with stability conditions on the embedded Markov chains, we show the following facts: (i) the ratio and the time average costs coincide in the class...

For a linear combination ∑ uj Xj of random variables, we are interested in the partial derivatives of its α-quantile Qα(u) regarded as a function of the weight vector u = (uj). It turns out that under suitable conditions on the joint distribution of (Xj) the derivatives exist and coincide with the conditional expectations of the Xi given that ∑ uj Xj takes the value Qα(u). Moreover, using this ...

In Boolean synthesis, we are given an LTL specification, and the goal is to construct a transducer that realizes it against an adversarial environment. Often, a specification contains both Boolean requirements that should be satisfied against an adversarial environment, and multi-valued components that refer to the quality of the satisfaction and whose expected cost we would like to minimize wi...

A cogent method is presented for computing the expected cost of an appointment schedule where customers are statistically identical, the service time distribution has known mean and variance, and customer no-shows occur with time-dependent probability. The approach is computationally efficient and can be easily implemented to evaluate candidate schedules within a schedule optimization algorithm.

We introduce a model for the computation of a multicommodity flow together with back-up flows for each commodity after any of a given set of failure states occurs in a network. We call such a total routing strategy a restorable multicommodity flow. One advantage of restorable flows over classical network protection methods, such as disjoint paths, is that the commodities may effectively share c...

In this paper, we extend our previous optimization investigation on a single cell (IEEE Transactions on Wireless Communications, vol. 8, no. 2, pp. 1038-1044, 2009) to a whole network with multiple cells and further consider the call admission control (CAC) based on the total expected discounted reward. Here, the system will get the award for admitting a call, but will incur a cost for rejectin...

Cost-benefit analysis is only applicable if the variances of both costs and benefits are finite. In the case of climate change, the variances of the net present marginal costs and benefits of greenhouse gas emission reduction need to be finite. Finiteness is hard, if not impossible to prove. The opposite is easier to establish as one only needs to show that there is one, not impossible represen...

This paper proposes a novel facility location model for health service network design by considering different key elements including the reliability aspects, service capacity, congestion, service quality, surrounding public infrastructures, geographical accessibility and several types of cost such as investment, transportation and operational costs. We formulate the problem as a robust scenari...