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Sequential selection of random vectors under a sum constraint

Published online by Cambridge University Press:  14 July 2016

Mario Stanke*
Affiliation:
Georg-August-Universität Göttingen
*
Postal address: Institut für Mikrobiologie und Genetik, Abteilung Bioinformatik, Georg-August-Universität Göttingen, Goldschmidtstraße 1, 37077 Göttingen, Germany. Email address: [email protected]

Abstract

We observe a sequence X 1, X 2,…, X n of independent and identically distributed coordinatewise nonnegative d-dimensional random vectors. When a vector is observed it can either be selected or rejected but once made this decision is final. In each coordinate the sum of the selected vectors must not exceed a given constant. The problem is to find a selection policy that maximizes the expected number of selected vectors. For a general absolutely continuous distribution of the X i we determine the maximal expected number of selected vectors asymptotically and give a selection policy which asymptotically achieves optimality. This problem raises a question closely related to the following problem. Given an absolutely continuous measure μ on Q = [0,1] d and a τQ, find a set A of maximal measure μ(A) among all AQ whose center of gravity lies below τ in all coordinates. We will show that a simplicial section { x Q | 〈 x , θ 〉 ≤ 1}, where θ ∈ ℝ d , θ 0, satisfies a certain additional property, is a solution to this problem.

Type
Research Papers
Copyright
Copyright © Applied Probability Trust 2004 

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