• CDE review
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• v.8 no.3
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• pp.40-51
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• 2002

Design and manufacturing (or production) must be closely interrelated. They should never be viewed as separate disciplines or activities. Each part or component of a product must be designed so that it not only meets design requirements and specifications, but also can be manufactured and assembled economically, ecologically and with relative ease. This approach improves productivity and allows a manufacturer to remain competitive. This broad view has become recognized as the area of design for manufacture and assembly(DFMA). Here the principles of the DFMA and their some examples are reviewed.

• Journal of the Korea Society of Computer and Information
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• v.23 no.7
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• pp.1-10
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• 2018

In this paper, we propose the principles and design details of Automatic cable assembly test system and show its utility. Testing the cable assembly is required periodically or non-periodically in the system that the cable assembly performance is quite important like military equipment. There are several weaknesses when humans test the cable assembly manually. It not only takes much time but also could happen human error. To improve these disadvantages, I developed Automatic cable assembly test system. The system can be implemented by building switching control system that connect and disconnect the cable assembly and measuring devices. Through the result of the cable assembly test with this test system, we show this system makes test time short and improves of test reliability as compared with manual test.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.30 no.11 s.254
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• pp.1433-1438
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• 2006

A systematic approach to socket shape design of a concave piston assembly for a high pressure hydraulic pump of an excavator is presented in this paper. A design model is given and a methodology of socket shape design is proposed. An axisymmetric rigid-plastic finite element method is employed for predicting the approximate socket shape formed by a rotary forming process as well as for simulating the test process for separating the shoe from the piston assembly designed. It is verified that the predictions are in good agreement with the experiments. The approach is successfully applied to developing an optimal concave piston assembly.

• Nuclear Engineering and Technology
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• v.30 no.4
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• pp.287-297
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• 1998

The elastic stiffness formula of leaf type holddown spring(HDS) assembly is verified by comparing the values of elastic stiffness with the characteristic test results of the HDS's specimens. The comparisons show that the derived elastic stiffness formula is useful in reliably estimating the elastic stiffness of leaf type HDS assembly. The elastic stiffness sensitivity of leaf type HDS assembly is analyzed using the formula and its gradient vectors obtained from the mid-point formula. As a result of sensitivity analysis, the elastic stiffness sensitivity with respect to each design variable is quantified and design variables of large sensitivity are identified. Among the design variables, leaf thickness is identified as the most sensitive design variable to the elastic stiffness of leaf type HDS assembly. In addition, the elastic stiffness sensitivity, with respect to design variable, is in power-law type correlation to the base thickness of the leaf.

• 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.

• Korean Journal of Computational Design and Engineering
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• v.13 no.5
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• pp.391-402
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• 2008

Today's product development environment is characterized as abrupt changes in consumer needs and short lifecycle of the product, which requires manufacturing companies to be equipped with time-to-market and time-to-volume strategies as prime factors for the successful product launch on market. They especially need to bring a product to the market faster with smart methodologies that enable assembly manufacturers to efficiently simulate and manage part assembly information throughout product development process. The research in this paper provides n e-manufacturing methodology considering geometric constraints in order to decide assembly process sequences. The methodology organizies the part layout (position & orientation) in order to optimize human postures during the assembly processes. As the case studies, assembly parts for two commercial products have been generated as CAD models and analyzed for the desired solutions for part assembly sequences using the proposed methodology.

• Journal of the Korean Operations Research and Management Science Society
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• v.22 no.4
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• pp.133-149
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• 1997

The major two steps required to design a cellular layout are cell formation and cell layout. Because of the differences between manufacturing and assembly operations, the logic of cell formation and cell layout between an FMS and an FAS is not the same. Since the time for the assembly operations is usualaly relatively short, the transfer time is thus very crucial for the performance of assembly systems. Transfore in a cellular FAS it is more important to eliminate backtracking operations in assembly planning, not to allow intercellular movements in cell formation, and to arrange machines according to assembly sequence in cell layout. This study presents a method for the integrated layout design in cellular FASs considering the characteristics of FAS, layout, and production factors.

• IE interfaces
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• v.6 no.2
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• pp.19-35
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• 1993

This paper presents the development of a knowledge-based expert system to assist for designer in the process of designing products for easier assembly. The developed expert system for supporting assembly-oriented product design, which is named as DFA-MASTER, consists of two subsystems such as "Assembly Method Selection System" which provides feasible assembly methods to designer and "DFA-Analysis System" which provides guidelines to improve assemblability of products in the early stage of product design. The developed system is interfaced with AutoCAD system and can be run under PC environments. By using DFA-MASTER, designer can obtain feasible assembly methods which have high assemblability under the given asssembly conditions and also evaluate the assemblability of part feature or product structure.

• Journal of the Korean Society for Precision Engineering
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• v.19 no.5
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• pp.72-80
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• 2002

DFA (Design for assembly) is a design philosophy for improving product designs for simpler or less costly assembly operations. This paper proposes a new DFA methodology that can estimate the standard assembly time and evaluate the assemblablity of parts. We select some determining and influencing factors related with assembly process, and estimate the assembly time using motion analysis. By the levels of the determining and influencing factors, the assemblability is evaluated, and finally, the tables that include the time and score of assembly is suggested.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.344-347
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• 2000

In this paper, a redesign of computer case is proposed by applying some guide lines of assembly and disassembly to an existing computer case. Some problems such as increase of number of disassembly and vibration, difficult assembly and disassembly from unfittable covers are recognized through analysis of geometrical structure and practical assembly and disassembly. A solution of these problems is proposed through ideas of ease of assembly and disassembly. Design for Environment Software is used to evaluate both redesigned and existing products. Time of assembly and disassembly and MET-point are especially calculated by the software, and these data give us a good guide for analysis of ease of assembly, ease of disassembly and environmental influence in both products.