• Journal of Korean Society of Industrial and Systems Engineering
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• v.29 no.4
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• pp.91-99
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• 2006

A POP system, which collects manufacturing data from the shop floors and supply them to higher level systems, should be maintained and upgraded according to the change of production environment such as new product introduction. This situation leads to the need of a cost-effective system development methodology. In this paper, a methodology based on the classification and the similarity comparison of manufacturing processes is proposed. In this, a new product is classified according to the similarity of its manufacturing processes, which enables recycling of existing system modules. The proposed methodology has been tested in the case of an electronics parts manufacturing company, where a POP system is implemented. The result shows that the proposed methodology can save time and efforts for system implementation.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.36 no.1
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• pp.24-35
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• 2013

A cell formation approach based on cluster analysis is developed for the configuration of manufacturing cells. Cell formation, which is to group machines and parts into machine cells and the associated part families, is implemented to add the flexibility and efficiency to manufacturing systems. In order to develop an efficient clustering procedure, this paper proposes a cluster analysis-based approach developed by incorporating and modifying two cluster analysis methods, a hierarchical clustering and a non-hierarchical clustering method. The objective of the proposed approach is to minimize intercellular movements and maximize the machine utilization within clusters. The proposed approach is tested on the cell formation problems and is compared with other well-known methodologies available in the literature. The result shows that the proposed approach is efficient enough to yield a good quality solution no matter what the difficulty of data sets is, ill or well-structured.

• International Journal of Railway
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• v.3 no.1
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• pp.28-33
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• 2010

The research is to develop cost methodology to support railway managers for identifying principles, tools and methods of activity based management correctly and precisely, and can be useful and effective for managers for realizing their goals. The research result a ministry can be suitable guideline in terms of how to execute activity based management. Since in this research, main and secondary activities are studied completely in the Railway organization, it can be an explanatory research. The research population is headquarter managers and experts of railway organization and the sampling procedure is goal-oriented and judgmental. 74 people were selected by using a formula. All hypotheses were tested in 95% significance level. Meanwhile a proposed process of applying. activity based management was offered.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.1761-1765
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• 2008

In the braking of a railroad car, mechanical brake systems using wheel tread and brake disk are applied as well as electrical brake systems by regenerator and rheostat. It is very important to consider the frictional characteristic because kinetic energy of the vehicle is dissipated as converted thermal energy through friction between disk and brake pad during disk braking. A friction coefficient and wear characteristic are decided from the interrelationship of disk and friction material in the disk brake system. Lab-scale dynamometer test on developed brake disk materials for increasing heat resistance was performed in this study. Each candidate material was tested at various braking speeds and pressures and we obtained the friction coefficient and wear characteristic. And we executed comparative evaluation of the result from the test.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.27 no.2
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• pp.9-15
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• 2019

The initial buckling of thin walled structures does not result in immediate failure. This post buckling capability is used to achieve light weight design, and final failure of thin walled structure is called crippling. To predict the failure load, empirical methods are often used for thin walled structures in design stage. But empirical method accuracy depend on geometry. In this study, experimental, empirical and numerical study of the crippling behavior of I-section beam made of carbon-epoxy are performed. The progressive failure analysis model to simulate the crippling failure is evaluated using the test results. In this study, commercial software LS-DYNA is utilized to compute the collapse load of composite specimen. Six kinds of specimens were tested in axial compression where correlation between analytical and experimental results has performed. From the results, we have partially conclude that the flange width-to-thickness ratio is found to influence the accuracy of empirical and numerical method.

• Asia-Pacific Journal of Business
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• v.10 no.1
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• pp.25-38
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• 2019

This study investigated the relationship between psychological ownership and the innovative behavior of Korean employees. This paper also examined whether job satisfaction positively mediates the above relationship. In addition, we address the moderating role and moderated mediation role of job engagement in the relationship between job satisfaction and innovative behavior. By using cross-sectional data, with questionnaires administered to 289 employees working in Korean hospitals, the main hypotheses were tested. The result of empirical analysis has shown that psychological ownership was significantly positively related to both employee innovative behavior. The results also found that job satisfaction positively mediated the relationship between psychological ownership and innovative behavior of employees. In addition, there was significant moderating effect of job engagement on the relationship between psychological ownership and job satisfaction and the moderating mediating role of job engagement was found.

• Journal of Korea Society of Digital Industry and Information Management
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• v.15 no.1
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• pp.123-132
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• 2019

As the one-person households with economic power have increased, the consumption culture changed as well. The primary purpose of this study is to investigate the on-line shopping motivation of one-person households in terms of consumer value. Economic value, emotional value, convenience value, social value were identified as affecting factors of satisfaction and intention to re-use of on-line shopping purchasing based on prior studies of on-line shopping behavior. This study tested the hypothesized model targeting 244 one-person households who have purchased products in on-line shopping mall. According to the results of analysis by using R, economic value, emotional value are significantly related to the consumer satisfaction but convenience value, social value are not. Consumer satisfaction of online purchasing was also shown to be related to the intention to re-use. However no difference between men and female was shown in shopping motivations. The research result can provide useful guidelines and strategies for one-person households with online shopping malls.

• International Journal of Oral Biology
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• v.43 no.4
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• pp.201-207
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• 2018

Porphyromonas gingivalis is among the major etiological pathogens of chronic periodontitis. The virulence mechanisms of P. gingivalis is yet to be identified as its activity is largely unknown in actual disease process. The purpose of this study is to identify antigens of P. gingivalis expressed only in patients with chronic periodontitis using a unique immunoscreening technique. Change Mediated Antigen Technology (CMAT), an antibody-based screening technique, was used to identify virulence-associated proteins of P. gingivalis that are expressed only during infection stage in patients having chronic periodontitis. Out of 13,000 recombinant clones screened, 22 tested positive for reproducible reactivity with rabbit hyperimmune anti-sera prepared against dental plaque samples acquired from periodontitis patients. The DNA sequences of these 18 genes were determined. CMAT-identified protein antigens of P. gingivalis included proteins involved in energy metabolism and biosynthesis, heme and iron binding, drug resistance, specific enzyme activities, and unknown functions. Further analysis of these genes could result in a novel insight into the virulence mechanisms of P. gingivalis.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.17 no.6
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• pp.31-37
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• 2018

In order to improve stability and controllability of SUV vehicle, Integrated Dynamics Control system with Steering system (IDCS) was developed. Eight degree of freedom vehicle model and front and rear steering system model were used to design IDCS system. It also employs Fuzzy logic control method to design integrate control system. The performance of IDCS was evaluated with two road conditions and several driving conditions. The result shows that SUV vehicle with IDCS tracked the reference yaw rate under all tested conditions. IDCS reduced the body slip angle also. It represents IDCS improves vehicle stability and steerability.

• Journal of Engineering Education Research
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• v.21 no.3
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• pp.20-30
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• 2018

The purpose of this study is to analyze the characteristics of college students majoring in the engineering on career decision difficulties and emotional and personality career difficulties. Data is consisted of 430 college students. We tested the research question by employing the PSM and the multi-regression model. The result showed that college students majoring in the engineering have difficulties in the information about self, the lack of information, and the outside control on career decision more than others. We suggested that career education and counseling of understanding themselves such as interesting, aptitude, and occupational value should be provided for students majoring in the engineering.