Title
Online Multistage Subset Maximization Problems.
Abstract
Numerous combinatorial optimization problems (knapsack, maximum-weight matching, etc.) can be expressed as subset maximization problems: One is given a ground set N = {1,..., n}, a collection F subset of 2(N) of subsets thereof such that; 2 F, and an objective (profit) function p : F -> R+. The task is to choose a set nullset is an element of F that maximizes p(S). We consider the multistage version (Eisenstat et al., Gupta et al., both ICALP 2014) of such problems: The profit function pt (and possibly the set of feasible solutions F-t) may change over time. Since in many applications changing the solution is costly, the task becomes to find a sequence of solutions that optimizes the trade-off between good per-time solutions and stable solutions taking into account an additional similarity bonus. As similarity measure for two consecutive solutions, we consider either the size of the intersection of the two solutions or the difference of n and the Hamming distance between the two characteristic vectors. We study multistage subset maximization problems in the online setting, that is, p(t) (along with possibly F-t) only arrive one by one and, upon such an arrival, the online algorithm has to output the corresponding solution without knowledge of the future. We develop general techniques for online multistage subset maximization and thereby characterize those models (given by the type of data evolution and the type of similarity measure) that admit a constant-competitive online algorithm. When no constant competitive ratio is possible, we employ lookahead to circumvent this issue. When a constant competitive ratio is possible, we provide almost matching lower and upper bounds on the best achievable one.
Year
DOI
Venue
2019
10.4230/LIPIcs.ESA.2019.11
Leibniz International Proceedings in Informatics
Keywords
Field
DocType
Multistage optimization,Online algorithms
Online algorithm,Discrete mathematics,Combinatorics,Data evolution,Similarity measure,Combinatorial optimization problem,Hamming distance,Knapsack problem,Mathematics,Maximization,Competitive analysis
Journal
Volume
ISSN
Citations 
144
1868-8969
0
PageRank 
References 
Authors
0.34
0
4
Name
Order
Citations
PageRank
Evripidis Bampis112.05
Bruno Escoffier243037.32
Kevin Schewior3379.79
Alexandre Teiller400.34