62 research outputs found
Experimental comparison of approximation algorithms for scheduling unrelated parallel machines.
On the size of systems of sets every t of which have an SDR, with an application of the wordt-case ratio of heuristics for packing problems
Revenue Maximization in an Optical Router Node Using Multiple Wavelengths
In this paper, an optical router node with multiple wavelengths is
considered. We introduce revenue for successful transmission and study the
ensuing revenue maximization problem. We present an efficient and accurate
heuristic procedure for solving the NP-hard revenue maximization problem and
investigate the advantage offered by having multiple wavelengths
How to detect a counterfeit coin: Adaptive versus non-adaptive solutions
In an old weighing puzzle, there are n3 coins that are identical in appearance. All the coins except one have the same weight, and that counterfeit one is a little bit lighter or heavier than the others, though it is not known in which direction. What is the smallest number of weighings needed to identify the counterfeit coin and to determine its type, using balance scales without measuring weights? This question was fully answered in 1946 by Dyson [The Mathematical Gazette 30 (1946) 231â234]. For values of n that are divisible by three, Dyson's scheme is non-adaptive and hence its later weighings do not depend on the outcomes of its earlier weighings. For values of n that are not divisible by three, however, Dyson's scheme is adaptive. In this note, we show that for all values n3 there exists an optimal weighing scheme that is non-adaptive
Realizing small tournaments through few permutations
Every tournament on 7 vertices is the majority relation of a
3-permutation profile, and there exist tournaments on 8 vertices that do not have this property. Furthermore every tournament on 8 or 9 vertices is the majority relation
of a 5-permutation profile
A REVERSIBLE ERLANG LOSS SYSTEM WITH MULTITYPE CUSTOMERS AND MULTITYPE SERVERS
We consider a memoryless Erlang loss system with servers S = {1, âŠ, J}, and with customer types C = {1, âŠ, I}. Servers are multitype, so that server j can serve a subset of customer types C(j). We show that the probabilities of assigning arriving customers to idle servers can be chosen in such a way that the Markov process describing the system is reversible, with a simple product form stationary distribution. Furthermore, the system is insensitive; these properties are preserved for general service time distributions
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