We develop a methodology for studying ''large deviations type'' questions. Our approach does not require that the large deviations principle holds, and is thus applicable to a larg class of systems. We study a system of queues with exponential servers, which share an arrival stream. Arrivals are...

The Cross Entropy method is a well-known adaptive importance sampling method for rare-event probability estimation, which requires estimating an optimal importance sampling density within a parametric class. In this article we estimate an optimal importance sampling density within a wider...

In this paper we describe a Sequential Importance Sampling (SIS) procedure for counting the number of vertex covers in general graphs. The performance of SIS depends heavily on how close the SIS proposal distribution is to a uniform one over a suitably restricted set. The proposed algorithm...

This discussion paper resulted in a publication in the <I>Siam Journal on Matrix Analysis and Applications (2011). Volume 32, issue 3, pages 665-684.<P> A sequence of real numbers (<I>x_n</I>) is Benford if the significands, i.e. the fractionparts in the floating-point representation of (<I>x_n</I>), are distributed...</i></i></p></i>

This discussion paper resulted in a publication in the <I>Mathematical Methods of Operations Research</I> (2005). Volume 62, issue 3, pages 467-483.<P> We develop a methodology for studying "large deviations type" questions. Our approach does not require that the large deviations principle holds, and is...</p></i>

In: <I>Proceedings Winter Simulation Conference</I>, 9-12 December 2012, pages 387-398.<P> In rare event simulation, we look for estimators such that the relative accuracy of the output is ''controlled'' when the rarity is getting more and more critical. Different robustness properties have been defined...</p></i>

We develop a methodology for studying “large deviations type” questions. Our approach does not require that the large deviations principle holds, and is thus applicable to a large class of systems. We study a system of queues with exponential servers, which share an arrival stream. Arrivals...

There are various importance sampling schemes to estimate rare event probabilities in Markovian systems such as Markovian reliability models and Jackson networks. In this work, we present a general state dependent importance sampling method which partitions the state space and applies the...