Research output: Contribution to journal › Article › peer-review
A simple rounding scheme for multistage optimization. / Bampis, Evripidis; Christou, Dimitris; Escoffier, Bruno et al.
In: Theoretical Computer Science, Vol. 907, 12.03.2022, p. 1-10.Research output: Contribution to journal › Article › peer-review
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TY - JOUR
T1 - A simple rounding scheme for multistage optimization
AU - Bampis, Evripidis
AU - Christou, Dimitris
AU - Escoffier, Bruno
AU - Kononov, Alexander
AU - Nguyen, Kim Thang
N1 - Funding Information: This work was partially funded by the grant ANR-19-CE48-0016 from the French National Research Agency ( ANR ). The research of the fourth author is supported by the Russian Science Foundation , grant 21-41-09017 . Publisher Copyright: © 2022 Elsevier B.V.
PY - 2022/3/12
Y1 - 2022/3/12
N2 - We consider the multistage framework introduced in (Gupta et al., Eisenstat et al., both in ICALP 2014), where we are given a time horizon and a sequence of instances of a (static) combinatorial optimization problem (one for each time step), and the goal is to find a sequence of solutions (one for each time step) reaching a tradeoff between the quality of the solutions in each time step and the stability/similarity of the solutions in consecutive time steps. We first introduce a novel rounding scheme, tailored for multistage problems, that accounts for the moving cost (or stability revenue) of adjacent solutions. Using this rounding scheme, we propose improved approximation algorithms for the multistage variants of Prize-Collecting Steiner Tree and Prize-Collecting Traveling Salesman problems. Furthermore, we introduce a 2-approximation algorithm for multistage Multi-Cut on trees, and we also show that our general scheme can be extended to maximization problems, by providing a 0.75-approximation algorithm for the multistage variant of MaxSat.
AB - We consider the multistage framework introduced in (Gupta et al., Eisenstat et al., both in ICALP 2014), where we are given a time horizon and a sequence of instances of a (static) combinatorial optimization problem (one for each time step), and the goal is to find a sequence of solutions (one for each time step) reaching a tradeoff between the quality of the solutions in each time step and the stability/similarity of the solutions in consecutive time steps. We first introduce a novel rounding scheme, tailored for multistage problems, that accounts for the moving cost (or stability revenue) of adjacent solutions. Using this rounding scheme, we propose improved approximation algorithms for the multistage variants of Prize-Collecting Steiner Tree and Prize-Collecting Traveling Salesman problems. Furthermore, we introduce a 2-approximation algorithm for multistage Multi-Cut on trees, and we also show that our general scheme can be extended to maximization problems, by providing a 0.75-approximation algorithm for the multistage variant of MaxSat.
KW - Approximation algorithms
KW - LP-rounding
KW - Multistage optimization
UR - http://www.scopus.com/inward/record.url?scp=85122933873&partnerID=8YFLogxK
U2 - 10.1016/j.tcs.2022.01.009
DO - 10.1016/j.tcs.2022.01.009
M3 - Article
AN - SCOPUS:85122933873
VL - 907
SP - 1
EP - 10
JO - Theoretical Computer Science
JF - Theoretical Computer Science
SN - 0304-3975
ER -
ID: 35321989