• Journal of the Korean Operations Research and Management Science Society
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• v.30 no.1
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• pp.27-41
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• 2005

This paper considers identical parallel machine scheduling problem. Each job has a processing time. due date. weight and family type. If a different type of job is followed by prior job. a family setup is incurred. A two phased heuristic is presented for minimizing the sum of weighted tardiness. In the first phase. using roiling horizon technique. group each job into same family and schedule each family. In the second phase. assign each job to machines using schedule obtained in the first phase. Extensive computational experiments and comparisons among other algorithms are carried out to show the efficiency of the proposed algorithm.

• Journal of the Korean Operations Research and Management Science Society
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• v.26 no.2
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• pp.69-83
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• 2001

The problem of minimizing total tardiness on a batch processing machine with incompatible job families when there are sequence independent setup times between families is studied where all jobs of the same family have identical processing times and jobs of different families cannot be processed together. A batch processing machine can process a number of jobs, within a maximal batch size, simultaneously as a batch. The processing time required of each batch is equal to the one of jobs. A dynamic programming algorithm which gives the optimal solution, and several heuristics are presented. Performance of simple dispatching rules based on due dates are compared, and the best of them is used as an initial solution for the decomposition algorithm, which is shown to give good schedules in relatively short computational time.

• Journal of Korean Institute of Industrial Engineers
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• v.36 no.2
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• pp.125-137
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• 2010

This study focuses on the problem of scheduling wafer lots of several product families in the deposition workstation in a semiconductor wafer fabrication facility. There are multiple identical parallel machines in the deposition workstation, and two types of setups, record-dependent setup and family setup, may be required at the deposition machines. A record-dependent setup is needed to find optimal operational conditions for a wafer lot on a machine, and a family setup is needed between processings of different families. We suggest two-phase heuristic algorithms in which a priority-rule-based scheduling algorithm is used to generate an initial schedule in the first phase and the schedule is improved in the second phase. Results of computational tests on randomly generated test problems show that the suggested algorithms outperform a scheduling method used in a real manufacturing system in terms of the sum of weighted flowtimes of the wafer lots.

• Journal of the Korean Operations Research and Management Science Society
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• v.18 no.1
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• pp.1-18
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• 1993

The family disaggregation model of hierarchical production planning (HPP) is the problem of (0 -1) mixed integer programming that minimizes the total sum of setup costs and inventory holding costs over the planning horizon. This problem is hard in a practical sense since optimal solution algorithms have failed to solve it within reasonable computation times. Thus effective familoy disaggregation algorithm should be developed for HPP. The family disaggregation algorithm developed in this paper consists of the first stage of finding initial solutions and the second stage of improving initial solutions. Some experimental results are given to verify the effectiveness of developed disaggregation algorithm.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2000.04a
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• pp.103-106
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• 2000

본 논문은 작업이 공정시간 등의 특성으로 인해 Family 로 구분되어지고 동일한 Family 내의 작업끼리만 배치로 구성할 수 있는 제조환경에서의 스케줄링에 관한 연구이다. 이때 배치의 최대크기는 정해져 있어 그 이하의 수로 구성된 작업들로 하나의 배치를 구성할 수 있다. 동일 Family 내의 작업은 작업시간이 동일하고 배치로 구성된 작업이 진행될 때 수에 관계없이 하나의 작업에 소요되는 시간과 동일한 시간이 소요된다. 또한 다른 Family 와의 작업이 이어질 때는 교제시간이 발생한다. 목적함수는 전체지연 시간을 최소화하는 것이며 납기는 동일한 Family 에 있는 작업일지라도 각 작업별로 주어진다. 이 목적함수의 최적해를 구할 수 있는 동적계획법을 제시하고 이를 응용한 발견적 기법을 개발, 적용하여 각각 성능비교를 실시하였다.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.16 no.28
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• pp.203-209
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• 1993

In Factory Automation environments such as FMS, the formation of machine-part based on GT should be considered. The purpose of this study is to develop a economic heuristic algorithm which considers various elements such as unit processing time, subcontract cost, and functional operation cost, machine processing capacity etc. When this proposed approach is applied to the real situation expected benefits are as follows: the reduction of production lead time work in process, labor force, tooling, rework and scrap, setup time, order time delivery, and paper work, etc.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2002.05a
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• pp.390-396
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• 2002

This study is concerned with the strict machine-cell and part-family grouping (MCPFG) in cellular manufacturing system design. Most of MCPFG methodologies often suffer from improper assignment of machines and parts in which exceptional machine has more common operations with machines in a cell other than its own cell and exceptional part has more operations through machines in a cell other than the cell corresponding to its own family. This results in the loss of similarity in part design or common setup of machines and the benefits from the conversion of job shop manufacturing into cellular manufacturing are lost. In this study, a two-phase methodology is proposed to find the machine-cells and part families under the strict constraints in which all machines and parts are assigned to its most proper cells and families. Test results with moderately medium-sized ill-structured MCPFG problems available from the literature show the substantial efficiency of the proposed approach.

• Communications of the Korean Mathematical Society
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• v.37 no.4
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• pp.1147-1170
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• 2022

In this paper, we introduce a new class of mappings called the generalized orthogonal F-Suzuki contraction for a family of multivalued mappings in the setup of orthogonal b-metric spaces. We established the existence of some common fixed point results without using any commutativity condition for this new class of mappings in orthogonal b-metric spaces. Moreover, we illustrate and support these common fixed point results with example. The results obtained in this work generalize and extend some recent and classical related results in the existing literature.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2005.05a
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• pp.947-951
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• 2005

The concept of group technology has been successfully applied to many production systems including flexible manufacturing systems. In this paper we apply group technology principles to the economic lot scheduling problem which has been intensively studied over 40 years. We obtain a production schedule of several family products on a single facility where setup times and costs can be reduced by using the concept of group technology. We develop a heuristic algorithm and a hybrid genetic algorithm for the group technology economic lot scheduling problem (GT-ELSP). Numerical example shows that the developed heuristic and the hybrid genetic algorithm outperform the existing heuristics.

• Journal of Korean Institute of Industrial Engineers
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• v.19 no.2
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• pp.23-34
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• 1993

Although there are numerous studies that address the problem of optimal machine grouping and part family classification for cellular manufacturing, little research has been reported that studies the conditions where cellular manufacturing is appropriate. This paper, in order to evaluate and compare the job shop with the GT cellular shop, the performance of those shops were simulated by using SIMAN. We tested the effect of independent variables including changes of product demands, intercell flow level, group setup time, processing time variability, variety of material handling systems, and job properties (ratio of processing time and material handling time). And also performance measures (dependent variables), such as machine utilization, mean flow time, average waiting time, and throughput rate, are discussed. Job shop model and GT cellular shop written in SIMAN simulation language were used in this study. These systems have sixteen machines which are aggregated as five machine stations using the macro feature of SIMAN. The results of this research help to better understand the effect of production factors on the performance of cellular manufacturing systems and to identify some of the necessary conditions required to make these systems perform better than traditional job shops. Therefore, this research represents one more step towards the characterization of shops which may benefit from cellular manufacturing.