Paper Info
Title
Extensions to online delay management on a single train line: new bounds for delay minimization and profit maximization
Abstract
We present extensions to the Online Delay Management Problem on a Single Train Line. While a train travels along the line, it learns at each station how many of the passengers wanting to board the train have a delay of δ. If the train does not wait for them, they get delayed even more since they have to wait for the next train. Otherwise, the train waits and those passengers who were on time are delayed by δ. The problem consists in deciding when to wait in order to minimize the total delay of all passengers on the train line. We provide an improved lower bound on the competitive ratio of any deterministic online algorithm solving the problem using game tree evaluation. For the extension of the original model to two possible passenger delays δ 1 and δ 2, we present a 3-competitive deterministic online algorithm. Moreover, we study an objective function modeling the refund system of the German national railway company, which pays passengers with a delay of at least Δ a part of their ticket price back. In this setting, the aim is to maximize the profit. We show that there cannot be a deterministic competitive online algorithm for this problem and present a 2-competitive randomized algorithm.
Year
DOI
Venue
2011
10.1007/s00186-011-0349-2
Math. Meth. of OR
Keywords
Field
DocType
online algorithm,profitability,competitive analysis,competitive ratio,objective function,randomized algorithm,public transportation,lower bound
Online algorithm,Randomized algorithm,Mathematical optimization,Upper and lower bounds,Ticket,Operations research,Minification,Profit maximization,Game tree,Mathematics,Competitive analysis
Journal
Volume
Issue
ISSN
74
1
1432-2994
Citations 
PageRank 
References 
6
0.47
6
Authors
3
Name
Order
Citations
PageRank
Sven O. Krumke130836.62
Clemens Thielen27515.11
Christiane Zeck361.15