Browsing by Author "Shen, SY"

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A route-neighborhood-based metaheuristic for vehicle routing problem with time windows
(1999-11-01)
Liu, FHF
;
Shen, SY
;
工業工程與管理學系
;
Department of Industrial Engineering and Management
In this paper, a two-stage metaheuristic based on a new neighborhood structure is proposed to solve the vehicle routing problem with time windows (VRPTW). Our neighborhood construction focuses on the relationship between route(s) and node(s). Unlike the conventional methods for parallel route construction, we construct routes in a nested parallel manner to obtain higher solution quality. Valuable information extracted from the previous parallel construction runs is used to enhance the performance of parallel construction. In addition, when there are only a few unrouted customers left, we design a special procedure for handling them. Computational results for 60 benchmark problems are reported. The results indicate that our approach is highly competitive with all existing heuristics, and in particular very promising for solving problems of large size. (C) 1999 Elsevier Science B.V. All rights reserved.
An overview of a heuristic for vehicle routing problem with time windows
(1999-10-01)
Liu, FHF
;
Shen, SY
;
工業工程與管理學系
;
Department of Industrial Engineering and Management
In this paper, a two-stage metaheuristic based on a new neighborhood structure is proposed to solve the vehicle routing problem with time windows. Our neighborhood construction focuses on the relationship between route(s) and node(s). Unlike the conventional methods for parallel route construction, we construct routes in a nested parallel manner to obtain higher solution quality. Computational results for 60 benchmark problems are reported. The results indicate that our approach is highly competitive with all existing heuristics, in particular very promising for solving problems with large size. (C) 1999 Elsevier Science Ltd. All rights reserved.
The fleet size and mix vehicle routing problem with time windows
(1999-07-01)
Liu, FH
;
Shen, SY
;
工業工程與管理學系
;
Department of Industrial Engineering and Management
This paper describes several insertion-based savings heuristics for the fleet size and mix vehicle routing problem with time window constraints. A certain number of candidate fleet compositions are recorded in the construction phase, followed by applying a composite improvement scheme on them to enhance the solution quality. Computational results on 168 sample problems are reported. We found that heuristics with the consideration of a sequential route construction parameter yielded very good results. In addition, results on the 20 benchmarking problems for the fleet and mix vehicle routing problem with no time window constraints also demonstrate the effectiveness of our heuristics.