• Korean Management Science Review
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• v.12 no.2
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• pp.105-127
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• 1995

This paper solves different machine-part group formation (MPGF) problems using genetic algorithms to demonstrate that it can be a new robust alternative to the conventional heuristic approaches for optimization problems. We first give an overview of genetic algorithms: Its principle, various considerations required for its implementation, and the method for setting up parameter values are explained. Then, we describe the MPGF problem which are critical to the successful operation of cellular manufacturing or flexible manufacturing systems. We concentrate on three models of the MPGF problems whose forms of the objective function and/or constraints are quite different from each other. Finally, numerical examples of each of the models descibed above are solved by using genetic algorithms. The result shows that the solutions derived by genetic algorithms are comparable to those obtained through problem-specific heuristic methods.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.04a
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• pp.432-437
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• 1997

In this paper, Fuzzy ART which is one of the competitive learing neural networks is applied to machine-part cell formation problem. A large matrix and varios types of machine-part incidence matrices, especially including bottle-neck machines, bottle-neck parts, parts shared by several cells, and machines shared by several cells are used to test the performannce of Fuzzy ART neural network as a cell formation algorithm. The result shows Fuzzy ART neral network can be efficiently applied to machine-part cell formation problem which are large, and/or have much imperfection as exceptions, bottle-neck machines, and bottle-neck parts.

• 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.

• IE interfaces
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• v.11 no.2
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• pp.119-124
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• 1998

This paper proposes a new part family classification system (IPFACS: Image Processing and Fuzzy ART based Clustering System), which incorporates image processing techniques and a modified fuzzy ART neural network algorithm. IPFACS can classify parts based on geometrical shape and manufacturing attributes, simultaneously. With a proper reduction and normalization of an image data through the image processing methods and adding method in the modified Fuzzy ART, different types of geometrical shape data and manufacturing attribute data can be simultaneously classified in the same system. IPFACS has been tested for an example set of hypothetical parts. The results show that IPFACS provides a good feasible approach to form families based on both geometrical shape and manufacturing attributes.

• Journal of Korea Society of Industrial Information Systems
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• v.26 no.4
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• pp.19-32
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• 2021

It is well known that any maintenance works for aircrafts must be carried out strictly in accordance with the specified maintenance manuals, especially for military airplanes. According to our previous studies, the largest portion of the maintenance jobs for military aircrafts is found to be related to the assembly/disassembly of various parts, which requires precise understanding of the work procedures as well as correlation between interconnected parts let alone grasping of the exact shapes of parts involved. However, the conventional manuals for aircraft maintenance have failed to provide enough information required for the efficient maintenance except for simple texts and vague pictures, which are far from being sufficient sets of information. On the contrary, unlike incomplete conventional manuals with poor contents, 3D modeling SW could provide us with not only powerful visualization tool even to see through inside any assembly but also freedom to watch parts under test from any angle we want. In addition, the maintenance personnels could learn the precise maintenance procedures through repeatedly watching 3D animated version of the maintenance work as if they were on the field. In this study, we have suggested the efficient procedures to develop 3D manual for aircraft maintenance using 3D modeling SW, Solidworks and implemented a 3D maintenance manual for Integrated Drive Generator(IDG) in Boeing 747. Characteristics of the developed 3D manual has been analyzed in comparison with the conventional ones as well. It is shown that the suggested method could be easily applied to develop a 3D maintenance manual for commercial airplanes since the maintenance works involving assembly/disassembly of major parts are very similar regardless of aircraft types.

• Physical Therapy Korea
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• v.9 no.4
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• pp.61-68
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• 2002

본 연구는 하퇴의지 착용자와 정상 성인간의 시간-거리, 운동형상학 변수를 조사하고 비교하기 위하여 실시하였다. 연구 대상자는 외상으로 인한 하퇴 절단자로서 내골격식 하퇴의지를 착용하고 독립적으로 보행이 가능한 20명과 연령, 신장으로 짝짓기한 대조군(matched control group) 20명이 참여하였다. 보행분석은 Vicon Clinical Manager Software (VCM)를 내장한 PC에 5개의 카메라가 연결되어 있는 Vicon 512 Motion Analysis System (MAS, Oxford Metrics Inc.)을 이용하였다. 하퇴의지 착용군의 단하지 지지시간이 정상 성인군에 비해 유의하게 짧았으며(p<.05), 하퇴의지 착용군에서 슬관절의 선전이 증가되었으며 족관절의 저측굴곡이 감소되었다(p<.05). 하퇴절단자들의 보행개선을 위해서는 하퇴절단자 개인의 보행능력에 알맞은 부품의 선택, 체계적인 보행훈련 및 평가, 보행능력 향상을 위한 근력강화 프로그램 등 체계적인 재활훈련 프로그램이 필요한 것으로 사료된다. 본 연구는 연구대상자의 수가 제한되어 있으므로 연구의 결과를 일반화하기에는 제한점이 있으나, 향후 편측 하퇴절단자의 보행연구에 대한 기초 자료로 사용될 수 있을 것이라고 생각된다.

• Korean Journal of Optics and Photonics
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• v.34 no.2
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• pp.66-71
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• 2023

Zoom lenses are now starting to be applied to mobile-phone cameras as well. A zoom lens applied to a mobile-phone camera is mainly used to capture images in the telephoto range. Such an optical system has a long focal length, similar to that of a high-magnification zoom optical system, so the position of the imaging device also shifts significantly, due to manufacturing errors of the lenses and mechanical parts. In the past, the positional shift of the imaging device was corrected by moving the first lens group and the total optical system, but this paper confirms that the position of the imaging device can be corrected by selecting any two moving lens groups. However, it is found that more distance must be secured in the front and rear of a moving lens group for this purpose.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.24 no.2
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• pp.167-175
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• 2024

Due to the Fourth Industrial Revolution, ICT(Information and Communication Technology) industry is becoming more important and sophisticated than ever. In B2B based ICT industry demand forecasting by analyzing the previous customer data is so important. RFM, one of customer relationship management models is a marketing technique that evaluates Recency, Frequency and Monetary value to predict customers behavior. RFM model has been studied focusing on the B2C based industry. On the other hand there is a lack of research on B2B based technology industry. Therefore this study applied it to B2B based high technology industry and considered T(technology collaboration) value, which are identified as important factors in the technology industry. To present an improved model for market performance in B2B technology industry, an empirical study was conducted on comparing the accuracy of the traditional RFM model and the improved RFM-T model. The objective of this study is to contribute to market performance by presenting an improved model in B2B based high technology industry.

• Journal of Intelligence and Information Systems
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• v.17 no.4
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• pp.1-17
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• 2011

In order to maintain customer satisfaction and to remain productive and efficient in today's global competition, mass customization is adopted in many leading companies. Mass customization through product family and product platform enables companies to develop new products with flexibility, efficiency and quick responsiveness. Thus, product family strategy based on product platform is well suited to realize the mass customization. Product family is defined as a group of related products that share common features, components, and subsystems; and satisfy a variety of market niches. The objective is to propose a product family design strategy that provides priority weights among product components by satisfying customer requirements. The decision making process for a new product development requires a multiple criteria decision making technique with feedback. An analytical network process is adopted for the decision making modeling and procedure. For the implementation, a netbook product known as a small PC which is appropriate for the product family model is adopted. According to the proposed architecture, the priority weight of each component for each product family is derived. The relationship between the customer requirement and product component is analyzed and evaluated using QFD model.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.15 no.4
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• pp.121-133
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• 2020

This study aims to measure the result of R&D support projects on the beneficiary companies of the World Class 300 project, a representative domestic middle market enterprise incubation project. In particular, beneficiary companies were classified into industry groups(materials, components, equipment, modules, consumer goods) and the empirical study was conducted on how the result of R&D support project was differentiated by each industry group's characteristics. The analysis was performed on 272 companies selected as WC300 project during 2011 to 2017. The result of Panel regression Analysis confirmed that R&D support project had divergent influences on the performance (net profit) of companies depending on which industry group they belong. The samples of materials, components, equipment companies turned out not to have statistical significance. The samples of modules companies showed negative correlations, while those of consumer goods was observed to have positive correlations. This study demonstrates that it is essential to plan and implement policies suited to the characteristics of each industry groups to maximize the effect of R&D support projects henceforward.