• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.2
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• pp.339-350
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• 1994

This paper presents a method for automatic generation of line balanced assembly sequences based on disassemblability and proposes a method of evaluating an assembly work time using neural networks. Since a line balancing problem in flexible assembly system requires a sophisticated planning method, reasoning about line balanced assembly sequences is an important field of concern for planning assembly lay-out. For the efficient inference of line balanced assembly sequences, many works have been reported on how to evaluate an assembly work time at each work station. However, most of them have some limitations in that they use cumbersome user query or approximated assembly work time data without considering assembly conditions. To overcome such criticism, this paper proposes a new approach to mathematically verify assembly conditions based on disassemblability. Based upon the results, we present a method of evaluating assembly work time using neural networks. The proposed method provides an effective means of solving the line balancing problem and gives a design guidance of planning assembly lay-out in flexible assembly application. An example study is given to illustrate the concepts and procedure of the proposed scheme.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2004.05a
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• pp.425-428
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• 2004

Flexible assembly line (FAL) is a production system that assembles various parts in unidirectional flow line with many constraints and manufacturing flexibilities. In this research we deal with a FAL balancing problem with the objective of minimizing the maximum workload allocated to the stations. However, almost all the existing researches do not appropriately consider various constraints due to the problem complexity. Therefore, this thesis addresses a balancing problem of FAL with many constraints and manufacturing flexibilities, unlike the previous researches. To solve this problem we use a genetic algorithm (GA). To apply GA to FAL, we suggest a genetic representation suitable for FAL balancing and devise evaluation method for individual's fitness and genetic operators specific to the problem, including efficient repair method for preserving solution feasibility. The experimental results are reported.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.31 no.1 s.256
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• pp.1-10
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• 2007

This paper presents a design guidance of jig/fixture for flexible manufacturing system based on the verification of a base assembly motion instability. In flexible assembly system, the base assembly needs to be maintained in its assembled state without being taken apart. This requires stability in motion while the base assembly is handled or tilted. Therefore, the instability of the base assembly motion should be considered when determining the guide line of designing jig/fixture by evaluating a degree of the motion instability of the base assembly. To derive the instability, first we inference collision free assembly directions by extracting separable directions for the mating parts and calculate the separability which gives informations as to how the parts can be easily separated. Using these results, we determine the instability evaluated by summing all the modified separabilities of each component part within base assembly.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.22 no.50
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• pp.209-219
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• 1999

This paper presents an efficient operational technique of material feeding process, trainning for multi-operations, machine conditions, and role of foreman and material-supplying man, for constructing the flexible assembly cells in the domestic electronic industries. And an practical method for computing the number of economical cells is also presented by the cost-effective model that compares the additional assembly machine requirement with the four reductive effects including WIP/finished goods inventory, the troubles in the assembly line, the opportunity loss for small order quantity, and amounts of production management due to the introduction of cell line. An case study is introduced in for a domestic electronic assembly line at the end.

• Journal of the Korean Operations Research and Management Science Society
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• v.30 no.1
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• pp.43-54
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• 2005

A flexible assembly line (FAL) is a production system that assembles various parts in unidirectional flow line with many constraints and manufacturing flexibilities. In this research we deal with a FAL balancing problem with the objective of minimizing the maximum workload allocated to the stations. However, almost all the existing researches do not appropriately consider various constraints due to the problem complexity. Therefore, this study addresses a balancing problem of FAL with many constraints and manufacturing flexibilities, unlike the previous researches. We use a genetic algorithm (GA) to solve this problem. To apply GA to FAL. we suggest a genetic representation suitable for FAL balancing and devise evaluation method for individual's fitness and genetic operators specific to the problem, including efficient repair method for preserving solution feasibility. After we obtain a solution using the proposed GA. we use a heuristic method for reassigning some tasks of each product to one or more stations. This method can improve workload smoothness and raise work efficiency of each station. The proposed algorithm is compared and analyzed in terms of solution quality through computational experiments.

• Journal of the Korean Operations Research and Management Science Society
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• v.18 no.1
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• pp.97-117
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• 1993

This paper considers inspection station location problem for a flexible assembly line that consists of multiple stages. By considering the trade-off between locating an station at an "early" stage and at a "late" stage, we have developed some dominance relations on a graph. Based on the dominance relations, we then present an algorithm that finds an optimal inspection plan and a heuristic approach that finds a near-optimal inspection plan. The effectiveness of these two algorithms is demonstrated by two numerical examples. numerical examples.

• Journal of the Korean Society for Precision Engineering
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• v.24 no.7 s.196
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• pp.39-48
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• 2007

This paper presents a method of a line balanced assembly sequence generation based on the verification of a disassemblability and a work time. To derive the disassemblability for a part to be disassembled, first we inference collision free assembly directions by extracting separable directions fur the part. And we determine the disassemblability defined by the separability and stability cost. The separability cost represents a facility of the part disassembly operation, and the stability cost which represents a degree of the stability for the base assembly motion. Based upon the results, we propose a new approach of evaluating work time using neural networks. The proposed assembly sequence generation provides an effective means of solving the line balancing problem and gives a design guidance of planning assembly lay-out in flexible manufacturing application. Example study is given to illustrate the concepts and procedure of the proposed schemes.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2000.04a
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• pp.153-158
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• 2000

This paper addresses an intelligent robot control system using an off-line programming to teach a precise assembly task of electronic components in a flexible way. The investigated task consists of three job: heat caulking test, soldering on a circuit board, and checking of soldering defects on the back cover of a camera. This study investigates the remodelling of the most complicated cell in terms of the accuracy and fault rate among the twelve cells in a camera back-cover assembly line. We have attempted to enhance back-cover assembly line. We have attempted to enhance soldering quality, to add task flexibility, to reduce failure rate, and to increase product reliability. This study modifies the cell structure, and improves the soldering condition. The developed all system implements the real-time control of assembly with vision data, and realized an easier task teaching on off-line programming.

• Journal of the Korea Society for Simulation
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• v.5 no.2
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• pp.1-12
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• 1996

Utilizing the simulation approaches, the dynamic production scheduling system FOLS(Flexible flowshop On-Line Simulation) is developed under the flexible flowshop environment. When an interruption such as machine failure/recovery is occurred at the shop floor, the FOLS system performs evaluations for job selection rule oriented alternatives, and generates a dynamic production schedule based on the collected current shop floor data. For the case study, the FOLS system is applied to the printed circuit card assembly(PCCA) line and simulation results are reported.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1992.04b
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• pp.159-168
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• 1992

생산라인의 line balancing이 흐름생산에 있어서 일관된 생산을 하기 위한 필수조건이다. 여러 다양한 제품을 생산하는 printed circuit board(PCB) 공장에서의 line balancing을 얻기 위해서는 mixed model line balancing절차를 설명하고자 한다.