This paper treats transience for queueing network models by considering an asso ciated uid model If starting from any initial condition the uid model explodes at a linear rate then the associated queueing network with i i d service times and a renewal arrival process explodes faster than any fractional power

Brown (1980), (1981) proved that the renewal function is concave if the interrenewal distribution is DFR (decreasing failure rate), and conjectured the converse. This note settles Brown’s conjecture with a class of counterexamples. We also give a short proof of Shanthikumar’s (1988) result that the DFR property is closed under geometric compounding.

We study bounds on the rate of convergence of aperiodic Markov chains on a general state space to the stationary distribution. Our results generalize previous results on convergence rates for Markov chains [23]. We also improve results from [9] on convergence rates in the local renewal theorem. The results are applied to delayed random walks.

Different genetic procedures are applied to increase robustness, namely two typologies of admissible mutations for the elite subpopulation subjected to zooming and mutation and reproduction for the remaining individuals. In order to further improve convergence rate, a user-defined population percentage, depending on individuals fitness, is replaced with new phenotypes, enforcing chromosomic ren...

Consider a two-dimensional delayed renewal risk model with a constant interest rate, where the claim sizes of the two classes form a sequence of independent and identically distributed random vectors following a common bivariate Sarmanov distribution. In the presence of heavytailed claim sizes, some asymptotic formulas are derived for the finite-time and infinite-time ruin probabilities.

Renewal is defined as the recovery of an extinguished response when the contexts of extinction and recall differ. Prominent hippocampal activity during context-related extinction can predict renewal. Dopaminergic antagonism during extinction learning impaired extinction and reduced hippocampal activation, without affecting renewal. However, to what extent dopaminergic stimulation during extinct...

This paper addresses sources contributing to the differences in the degree of recovery from extinction observed with different renewal paradigms. In two lick suppression experiments with rats, we assessed the role of the associative status of the acquisition context in both the weakness of AAC renewal and the sometimes observed weaker renewal resulting from an ABC design relative to an ABA desi...

At present the world is experiencing an extraordinary rate of urbanization. India is also in a major phase of urbanization. Almost all Indian cities have grown up beyond their limits. Thus, the ecological footprint, which is the ‘area of wilderness of both land and sea needed to supply resources to a human population and needed to assimilate human waste’ of these cities is at the warning stage....

The present study characterized renewal of sucrose-seeking behavior in rats (Experiment 1). The role of the dopamine subtype-2 (D(2)) receptors in mediating renewal of sucrose-seeking behavior also was examined (Experiment 2). Rats were trained to respond for sucrose pellets (45mg each) on a fixed-ratio 25 (Experiments 1 and 2) schedule of reinforcement in Context A. Following acquisition, rats...