Efficient solutions to some transportation problems with applications to minimizing robot arm travel
SIAM Journal on Computing
Preemptive ensemble motion planning on a tree
SIAM Journal on Computing
Nonpreemptive ensemble motion planning on a tree
Journal of Algorithms
Information and Computation
STOC '94 Proceedings of the twenty-sixth annual ACM symposium on Theory of computing
Scheduling Parallel Machines On-line
SIAM Journal on Computing
Routing a vehicle of capacity greater than one
Discrete Applied Mathematics
Scheduling Jobs that Arrive Over Time (Extended Abstract)
WADS '95 Proceedings of the 4th International Workshop on Algorithms and Data Structures
The Finite Capacity Dial-A-Ride Problem
FOCS '98 Proceedings of the 39th Annual Symposium on Foundations of Computer Science
Faster approximation algorithms for the minimum latency problem
SODA '03 Proceedings of the fourteenth annual ACM-SIAM symposium on Discrete algorithms
News from the Online Traveling Repairman
MFCS '01 Proceedings of the 26th International Symposium on Mathematical Foundations of Computer Science
Online Dial-a-Ride Problems: Minimizing the Completion Time
STACS '00 Proceedings of the 17th Annual Symposium on Theoretical Aspects of Computer Science
APPROX '02 Proceedings of the 5th International Workshop on Approximation Algorithms for Combinatorial Optimization
On-Line Dial-a-Ride Problems under a Restricted Information Model
ESA '02 Proceedings of the 10th Annual European Symposium on Algorithms
The Online Dial-a-Ride Problem under Reasonable Load
CIAC '00 Proceedings of the 4th Italian Conference on Algorithms and Complexity
News from the online traveling repairman
Theoretical Computer Science - Mathematical foundations of computer science
On-Line Algorithms for the Dynamic Traveling Repair Problem
Journal of Scheduling
Algorithms for the on-line quota traveling salesman problem
Information Processing Letters
A Hard Dial-a-Ride Problem that is Easy on Average
Journal of Scheduling
Discrete Applied Mathematics - Special issue: Traces of the Latin American conference on combinatorics, graphs and applications: a selection of papers from LACGA 2004, Santiago, Chile
Theoretical Computer Science - Approximation and online algorithms
A heuristic for the Stacker Crane Problem on trees which is almost surely exact
Journal of Algorithms
Online Routing Problems: Value of Advanced Information as Improved Competitive Ratios
Transportation Science
The on-line asymmetric traveling salesman problem
Journal of Discrete Algorithms
On the power of lookahead in on-line server routing problems
Theoretical Computer Science
A new formulation for the Traveling Deliveryman Problem
Discrete Applied Mathematics
New lower bounds for online k-server routing problems
Information Processing Letters
On an Online Traveling Repairman Problem with Flowtimes: Worst-Case and Average-Case Analysis
COCOON '09 Proceedings of the 15th Annual International Conference on Computing and Combinatorics
Simulation of a large scale dynamic pickup and delivery problem
Proceedings of the 3rd International ICST Conference on Simulation Tools and Techniques
Online dial-a-ride problem with time-windows under a restricted information model
AAIM'06 Proceedings of the Second international conference on Algorithmic Aspects in Information and Management
On minimizing the maximum flow time in the online dial-a-ride problem
WAOA'05 Proceedings of the Third international conference on Approximation and Online Algorithms
On-Line algorithms, real time, the virtue of laziness, and the power of clairvoyance
TAMC'06 Proceedings of the Third international conference on Theory and Applications of Models of Computation
On the online dial-a-ride problem with time-windows
AAIM'05 Proceedings of the First international conference on Algorithmic Applications in Management
The on-line asymmetric traveling salesman problem
WADS'05 Proceedings of the 9th international conference on Algorithms and Data Structures
Online k-server routing problems
WAOA'06 Proceedings of the 4th international conference on Approximation and Online Algorithms
Algorithms for on-line order batching in an order picking warehouse
Computers and Operations Research
Hi-index | 5.23 |
In this paper results on the dial-a-ride problem with a single server are presented. Requests for rides consist of two points in a metric space, a source and a destination. A ride has to be made by the server from the source to the destination. The server travels at unit speed in the metric space and the objective is to minimize some function of the delivery times at the destinations. We study this problem in the natural on-line setting. Calls for rides come in while the server is traveling. This models, e.g. the taxi problem, or, if the server has capacity more than a minibus or courier service problem. For the version of this problem in which the server has infinite capacity having as objective minimization of the time the last destination is served, we design an algorithm that has competitive ratio 2. We also show that this is best possible, since no algorithm can have competitive ratio better than 2 independent of the capacity of the server. Besides, we give a simple 2.5-competitive algorithm for the case with finite capacity. Then we study the on-line problem with objective minimization of the sum of completion times of the rides. We prove a lower bound on the competitive ration of any algorithm of 1 + 2 for a server with any capacity and of 3 for a server has infinite capacity and the metric space is the real line. The algorithm has competitive ration 15. Copyright 2001 Elsevier Science B.V.