Optimal scheduling of emergency roadway repair and subsequent relief distribution
Computers and Operations Research
A hybrid approach to convoy movement planning in an urban city
IAAI'08 Proceedings of the 20th national conference on Innovative applications of artificial intelligence - Volume 3
Ontologies for Rapid Integration of Heterogeneous Data for Command, Control, & Intelligence
Proceedings of the 2010 conference on Ontologies and Semantic Technologies for Intelligence
Logistical support scheduling under stochastic travel times given an emergency repair work schedule
Computers and Industrial Engineering
| Hi-index | 0.00 |
We give a formal specification for a strategic network routing problem known as the convoy movement problem (CMP) and establish that the corresponding feasibility problem is NP-complete. We then introduce an integer programming (IP) model based on the concept of a time-space network and apply a Lagrangian relaxation to this model. We discuss how the dual function may be evaluated using a modified version of Dijkstra's algorithm suitable to very large, implicitly defined graphs and show how heuristic solutions to the primal problem may be obtained. We present results for a number of instances of the CMP, most of which are based on real-world problems. The number of convoys in these instances varies between 15--25, and their movement time requires up to several thousand time units in networks ranging in size from a few dozen to several thousand vertices and edges. The most difficult instance tested involves 17 long convoys each taking four times the average link travel time to pass through a point in the network. This instance is solved within 3.3% of optimality in less than 3.5 hours of computing time on a Dell Precision 420 dual processor computer. Every other test instance is solved within 2% of the optimal value in less than 20 minutes of computing time.