Browsing by Author "Tian, Y."

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A scheduling model for the refurbishing process in recycling management
(2013-11-01)
Cheng, T. C. E.
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Lin, B. M. T.
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Tian, Y.
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資訊管理與財務金融系註：原資管所+財金所
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Department of Information Management and Finance
We propose from the perspective of operations scheduling a novel model of the refurbishing process in recycling management. We model the refurbishing process as a two-stage flowshop that dismantles products into parts in stage one and refurbishes the parts on dedicated machines in stage two. The model also features that the performance measure of a schedule is defined by operation-based completion times, which is different from the job-based performance measures traditionally adopted in the scheduling literature. We analyse the optimality properties and computational complexity of some special cases of the problem. We derive lower bounds on the optimal solution based on a disaggregation technique and the assignment problem, and develop dominance rules incorporating estimates of the effects of partial schedules on unscheduled jobs. We present a heuristic approach, based on LP relaxation, and analyse its performance ratio. We also develop two metaheuristic algorithms, based on iterated local search and ant colony optimisation, to produce approximate solutions. The results of computational experiments show that the metaheuristics generate better solutions than the simple weighted shortest processing time dispatching rule, and the NEH-based and CDS-based algorithms, which are commonly deployed to treat the classical two-machine flowshop scheduling problem.
Guest Editorial Special Issue on Deep/Reinforcement Learning and Games
(2018-12-01)
Wu, I. -C.
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Lee, C. -S.
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Tian, Y.
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Mueller, M.
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資訊工程學系
Scheduling of a two-stage differentiation flowshop to minimize weighted sum of machine completion times
(2009-11-01)
Cheng, T. C. E.
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Lin, B. M. T.
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Tian, Y.
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資訊管理與財務金融系註：原資管所+財金所
;
Department of Information Management and Finance
This paper considers the problem of scheduling a two-stage flowshop that consists of a common critical machine in stage one and two independent dedicated machines in stage two. All the jobs require processing first on the common critical machine. Each job after completing its critical operation in stage one will proceed to the dedicated machine of its type for further processing in stage two. The objective is to minimize the weighted sum of stage-two machine completion times. We show that the problem is strongly NP-hard, and develop an O(n(3)) polynomial time algorithm to solve the special case where the sequences of both types of jobs are given. We also design an approximation algorithm with a tight performance ratio of 4/3 for the general case. (C) 2009 Elsevier Ltd. All rights reserved.