Browsing by Author "Hsieh, LF"

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Heuristic algorithm for the design of facilities layout and AGV routes in tandem AGV systems
(1997-03-01)
Hsieh, LF
;
Sha, DY
;
交大名義發表
;
工業工程與管理學系
;
National Chiao Tung University
Considering the necessity for the integrated design of facilities layout and material handling systems, this paper develops a heuristic algorithm to solve the facilities layout and AGV routes problems simultaneously in a tandem automated guided vehicle (AGV) system. A tandem AGV system is composed of several nonoverlapping closed loops; each loop is traversed by a vehicle. Based on this system in which bi-directional vehicles are used, distance and material now between pickup/deposit stations are considered simultaneously during the design of the facilities layout. In the meantime, several transit stations would handle the transportation between loops. As its subject, this paper proposes a heuristic algorithm to implement the facilities layout within each loop and the route of each vehicle in order to reduce the material handling cost It is proved that the heuristic algorithm is polynomial time complexity with O(n(4)).
Heuristic algorithm for the design of facilities layout and AGV routes in tandem AGV systems
(1997-03-01)
Hsieh, LF
;
Sha, DY
;
工業工程與管理學系
;
Department of Industrial Engineering and Management
Considering the necessity for the integrated design of facilities layout and material handling systems, this paper develops a heuristic algorithm to solve the facilities layout and AGV routes problems simultaneously in a tandem automated guided vehicle (AGV) system. A tandem AGV system is composed of several nonoverlapping closed loops; each loop is traversed by a vehicle. Based on this system in which bi-directional vehicles are used, distance and material now between pickup/deposit stations are considered simultaneously during the design of the facilities layout. In the meantime, several transit stations would handle the transportation between loops. As its subject, this paper proposes a heuristic algorithm to implement the facilities layout within each loop and the route of each vehicle in order to reduce the material handling cost It is proved that the heuristic algorithm is polynomial time complexity with O(n(4)).
Wafer rework strategies at the photolithography stage
(2001-06-01)
Sha, DY
;
Hsieh, LF
;
Chen, KJ
;
工業工程與管理學系
;
Department of Industrial Engineering and Management
Defective wafers are often seen during the semiconductor manufacturing process. Technically, there is no known remedy for a defective wafer. However, at the photolithography phase of semiconductor manufacturing, the defective wafers can be reworked to reduce the manufacturing cost significantly. In this paper, when comparing the three rework strategies that were proposed by Zargar, we pinpoint the disadvantages of each and offer two other strategies. We assess the advantages and disadvantages of the five rework strategies of each reworked batch according to total cycle time, the quantity of work-in-process, each machine's utilization rate, the utilization rate of photolithography, and the average length of queues for photolithography. Through simulations and statistics, the fifth strategy is shown to be superior to the first four and most suitable for wafer manufacturing. Significance: At the photolithography stage, the processing relation between lot and lot should be considered. Thus, how to schedule reworking in order to reduce the effect on waiting lots is a crucial issue for wafer manufacturing management.