We consider an MXI ell queueing system with N-policy and single vacation. As soon as the system becomes empty, the server leaves the system for a vacation of random length 11: When he returns from the vacation, if the system size is greater than or equal to a pretermined value N(threshold), he begins to serve the customers. If not, the server waits in the system until the system size reaches or...

Informal settlement in Kabul Why and how should Kabul upgrade its informal settlements? Informal settlements shelter about 80% of Kabul’s population (2.44 million people), cover 69% of the city’s residential land, and represent a fixed private capital investment of US$2.5 billion (not including land value). The size, scale, and contribution to the economy of informal settlements force the poli...

This paper studies the deviations of the regret in a stochastic multi-armed bandit problem. When the total number of plays n is known beforehand by the agent, Audibert et al. [2] exhibit a policy such that with probability at least 1− 1/n, the regret of the policy is of order log n. They have also shown that such a property is not shared by the popular ucb1 policy of Auer et al. [3]. This work ...

Given an M=G=1 queue controlled by an exhaustive policy P, we consider a (P+ )-policy consisting of turning the server on at a random time later than P. The objective is to obtain necessary and su cient conditions such that the (P+ )-policy are better than the P-policy. Under the in nite-horizon average-cost criterion, policies are compared when the costs assumed are linear. When the holding co...

EDITORIAL INTRODUCTION. From mass incarceration to targeted policing: Introduction to the Special Issue . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Richard Rosenfeld EXECUTIVE SUMMARY. Overview of “Imprisonment and crime: Can both be reduced?” . . . . . . 9 Steven N. Durlauf, Daniel S. Nagin RESEARCH ARTICLE. Impr...

We study a finite buffer N-policy GI/M(n)/1 queue with Bernoulli-schedule vacation interruption. The server works with a slower rate during vacation period. At a service completion epoch during working vacation, if there are at least N customers present in the queue, the server interrupts vacation and otherwise continues the vacation. Using the supplementary variable technique and recursive met...

This paper studies optimal switching on and off of the entire service capacity of an M/M/∞ queue with holding, running and switching costs. The running costs depend only on whether the system is on or off, and the holding costs are linear. The goal is to minimize average costs per unit time. The main result is that an average-cost optimal policy either always runs the system or is an (M,N)-poli...

We review some known results and state a few versions of an open problem related to the scaling of the total queue size (in steady state) in an n×n input-queued switch, as a function of the port number n and the load factor ρ. Loosely speaking, the question is whether the total number of packets in queue, under either the maximum weight policy or under an optimal policy, scales (ignoring any lo...