Classical ecological theory predicts that environmental stochasticity increases extinction risk by reducing the average per-capita growth rate of populations. For sedentary populations in a spatially homogeneous yet temporally variable environment, a simple model of population growth is a stochastic differential equation dZ(t) = μZ(t)dt + σZ(t)dW(t), t ≥ 0, where the conditional law of Z(t+Δt)-...

A government agency delegates to a provider (hospital, medical gatekeeper, school, social worker) the decision to supply a service or treatment to individual recipients. The agency does not perfectly know the distribution of individual treatment costs in the population. The single-crossing property is not satisfied when the uncertainty pertains to the dispersion of the distribution. We find tha...

Results Cubic Clustering Criterion, pseudo F and t statistics revealed a twoand a six-cluster model. The first cluster (n=23) was found in both models and consists of patients who present with an “IL-5-high and IL-17F-high” profile. Patients with an “IL-4or IL-13-high” profile did not cluster in one single group. In the six-cluster model, the “IL-17F-low” group was divided into 5 separate clust...

Warranty is now an integral part of each product. Since its length is directly related to the cost of production, it should be set in such a way that it would maximize revenue generation and customers’ satisfaction. Furthermore, based on the behavior of customers, it is assumed that increasing the warranty period to earn the trust of more customers leads to more sales until the market is sat...