We introduce the first class of perfect sampling algorithms for the steady-state distribution of multiserver queues with general interarrival time and service time distributions. Our algorithm is built on the classical dominated coupling from the past protocol. In particular, we use a coupled multi-server vacation system as the upper bound process and develop an algorithm to simulate the vacati...

In this paper we describe a perfect simulation algorithm for the stableM/G/c queue. Sigman (2011: Exact Simulation of the Stationary Distribution of the FIFO M/G/c Queue. Journal of Applied Probability, 48A, 209–213) showed how to build a dominated CFTP algorithm for perfect simulation of the super-stable M/G/c queue operating under First Come First Served discipline, with dominating process pr...

In the “mixed hypergraph” model, proper coloring requires that vertex subsets of one type (called C-edges) should contain two vertices of the same color, while the other type (D-edges) should not be monochromatic. Voloshin [Australas. J. Combin. 11 (1995), 25–45] introduced the concept of C-perfectness, which can be viewed as a dual kind of graph perfectness in the classical sense, and proposed...

A perfect code in a graph Γ = (V,E) is a subset C of V that is an independent set such that every vertex in V \ C is adjacent to exactly one vertex in C. A total perfect code in Γ is a subset C of V such that every vertex of V is adjacent to exactly one vertex in C. A perfect code in the Hamming graph H(n, q) agrees with a q-ary perfect 1-code of length n in the classical setting. A necessary a...

This contribution describes the morphology and energetic stability of different types of nanostructured carbon, including fullerenes, nanotubes, scrolls, peapods, and more complex foams. When structurally perfect, these systems are very stable even under extreme conditions. Specific structural defects offer an unusual, energetically accessible path to an inter-conversion between different isome...

We consider a model of (spatial) voting with endogenous timing. In line with actual political campaigns, candidates can decide endogenously when and where to locate. More specifically, we analyze endogenous timing in a two-period n-candidate spatial-votinggame. We show that this game possesses a pure-strategy equilibrium∗ (OSBORNE [1993]) but no – or only very complex – subgame-perfect equilibr...