• Journal of Korean Institute of Industrial Engineers
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• v.29 no.3
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• pp.213-221
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• 2003

In this paper, we consider a multi-objective part-machine grouping problem, in which part types have several alternative part routings and each part routing has a machining sequence. This problem is characterized as optimally determining part type sets and its corresponding machine cells such that the sum of inter-cell part movements and the sum of machine workload imbalances are simultaneously minimized. Due to the complexity of the problem, a two-stage heuristic algorithm is proposed, and experiments are shown to verify the effectiveness of the algorithm.

• Korean Management Science Review
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• v.16 no.1
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• pp.157-171
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• 1999

In a increasingly competitive marketplace, the manufacturing companies have no choice but looking for ways to improve productivity to sustain their competitiveness and survive in the industry. Recently cellular manufacturing has been under discussion as an option to be easily implemented without burdensome capital investment. The objective of cellular manufacturing is to realize many aspects of efficiencies associated with mass production in the less repetitive job-shop production systems. The very first step for cellular manufacturing is to group the sets of parts having similar processing requirements into part families, and the equipment needed to process a particular part family into machine cells. The underlying problem to determine the part and machine assignments to each manufacturing cell is called the cell formation. The purpose of this study is to develop a clustering algorithm based on the neural network approach which overcomes the drawbacks of ART1 algorithm for cell formation problems. In this paper, a generalized learning vector quantization(GLVQ) algorithm was devised in order to transform a 0/1 part-machine assignment matrix into the matrix with diagonal blocks in such a way to increase clustering performance. Furthermore, an assignment problem model and a rearrangement procedure has been embedded to increase efficiency. The performance of the proposed algorithm has been evaluated using data sets adopted by prior studies on cell formation. The proposed algorithm dominates almost all the cell formation reported so far, based on the grouping index($\alpha$ = 0.2). Among 27 cell formation problems investigated, the result by the proposed algorithm was superior in 11, equal 15, and inferior only in 1.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2001.12a
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• pp.78-82
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• 2001

Electronic Weighting Machine is used an electronic scale which has many trouble because of broken load cells. In this paper, we propose an intelligent Diagnosis System will for an electronic weighting machine using fuzzy logic. It's purpose be detect of the load cell's trouble. The electronic circuit of system, which call 'junction box', will be connected resistances in a series at circuit of Wheatstone Bridge for monitoring the condition of load cells.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1995.04a
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• pp.122-129
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• 1995

This paper presents a similarity coefficient based approach to the problem of machine-part grouping for cellular manufacturing. The method uses relevant production data such as part type, production volume, routing sequence to make machine cells and part families for cell formation. A new similarity coefficient using weighted factors is introduced and an algorithm for formation of machine cells and part families is developed. A comparative study of two similarity coefficients - Gupta and seifoddini's method and proposed method - is conducted. A software program using TURBO C has been developed to verify the implementation.

• Journal of Korean Institute of Industrial Engineers
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• v.22 no.1
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• pp.141-154
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• 1996

This paper presents a similarity coefficient based approach to the problem of machine-part grouping for cellular manufacturing. The method uses relevant production data such as part type, production volume, routing sequence to make machine cells and part families for cell formation. A new similarity coefficient using weighted factors is introduced and an algorithm for formation of machine cells and part families is developed. A comparative study of two similarity coefficient methods, Gupta and Seifoddini's method and the proposed method, is conducted.

• Journal of Bio-Environment Control
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• v.6 no.1
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• pp.55-65
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• 1997

This study was conducted to develop a robotic transplanter for bedding plants. The robotic transplanter consisted of machine vision system, manipulator attached with the specially designed gripper, and plug tray transfer system. Results of this study were as follows. 1. A machine vision system for a robotic transplanter was developed. The success rates of detecting empty cells and bad seedlings in 72-cell and 128-cell plug-trays for cucumber seedlings were 98.8％ and 94.9％ respectively. The success rates of identifying leaf orientation for 72- cell and 128-cell plug-trays were 93.5% and 91.0%, respectively. 2. A cartesian coordinate manipulator for a robotic transplanter with 3 degrees of freedom was constructed. The accuracy of position control was $\pm$ 1mm. 3. The robotic transplanter was tested with a shovel-type finger. Without considering leaf orientation, the success rates of transplanting healthy cucumber seedlings for 72-cell and 128-cell plug-trays were 95.5% and 94.5%, respectively. Considering leaf orientation, the success rates of transplanting healthy cucumber seedling in 72-cell and 128-cell plug-trays were 96.0% and 95.0%, respectively.

• Journal of the Semiconductor & Display Technology
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• v.17 no.3
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• pp.59-64
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• 2018

In recent years, the solar cell market has steadily grown with the demand for new energies. And wire sawing is one of the most critical processes in manufacturing solar cell wafer which is supposed to affect the breakage of wafers most during the process and afterwards. Generally, the defects of the wafers are generated from the structural vibrations of the machine. In the sawing process, the vibrations cause unnecessary normal stress on the cut surface of wafers, and eventually create the surface damage or leave the residual stress. In this study, the dynamic properties of a wire saw have been analyzed through the frequency response test and the computer simulation. And the effects of the design alterations have been investigated to stabilize the machine structure and further to reduce the vibrations. The result shows that relatively simple design alterations of supporting structure without any change of major parts of the machine can suppress the vibrations of the machine effectively.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1996.10a
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• pp.315-318
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• 1996

The machine-part cell formation means the grouping of similar parts and similar machines into families in order to minimize bottleneck machines, bottleneck parts, and inter-cell part movements in cellular manufacturing systems and flexible manufacturing systems. The cell formation problem is knows as a kind of NP complete problems. This paper briefly introduces the cell-formation problem and proposes a cell formation method based on the Kohonen's self-organizing feature map which is a neural network model. It also shows some experiment results using the proposed method. The proposed method can be easily applied to the cell formation problem compared to other meta-heuristic based methods. In addition, it can be used to solve large-scale cell formation problems.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.21 no.45
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• pp.329-332
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• 1998

This Paper proposes a mathematical model to solve the cell formation problem with exceptional elements, Exceptional elements are bottleneck machines and exceptional parts that span two or more manufacturing cells. The model suggests whether it is cost-effective to eliminate an EE (by machine duplication or part subcontracting), or whether the intercellular transfer caused by the EE should remain in the cell formation. It provides an optimal solution for resolving the interaction created by EE in the initial cell formation solution. In addition, the model recognizes potentially advantageous mixed strategies ignored by previous approaches.

• Industrial Engineering and Management Systems
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• v.15 no.1
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• pp.11-18
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• 2016

This paper considers a scheduling problem in a flexible job shop with a reconfigurable manufacturing cell. The flexible job shop has both operation and routing flexibilities, which can be represented in the form of a multiple process plan, i.e. each part can be processed through alternative operations, each of which can be processed on alternative machines. The scheduling problem has three decision variables: (a) selecting operation/machine pairs for each part; (b) sequencing of parts to be fed into the reconfigurable manufacturing cell; and (c) sequencing of the parts assigned to each machine. Due to the reconfigurable manufacturing cell's ability of adjusting the capacity, functionality and flexibility to the desired levels, the priority scheduling approach is proposed in which the three decisions are made at the same time by combining operation/machine selection rules, input sequencing rules and part sequencing rules. To show the performances of various rule combinations, simulation experiments were done on various instances generated randomly using the experiences of the manufacturing experts, and the results are reported for the objectives of minimizing makespan, mean flow time and mean tardiness, respectively.