• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.772-775
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• 2002

The remote handling and maintenance devices in the nuclear hot ceil should be checked prior to the hot operation in view of reliability and operability. In this study, the digital mock-up is implemented to analyze and define the process equipment maintenance processes instead of real mock-up, which is very expensive and time consuming. To do this, the parts of equipment and maintenance devices are modeled in 3-D graphics, assembled, and kinematics is assigned. Also, the virtual workcell of the spent fuel management process is implemented in the graphical environment which is the same as the real environment. This simulator has the several functions for verification such as analyses for the manipulator's working area, the collision detection, the path planning and graphic simulation of the processes etc. This graphic simulator of the maintenance devices can be effectively used in designing of the maintenance processes for the hot cell equipment and enhance the reliability of the spent fuel management.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.29 no.11 s.242
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• pp.1488-1493
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• 2005

In this study, fatigue tests to obtain S-N curves and FE analyses to obtain structural stress concentration factors were conducted for the two types of cruciform fillet welded joints, that is, load-carrying and non load-carrying types. Then we changed the obtained S-N curve of load carrying joint to that based on hot spot stress. As a result, the S-N curve of load carrying joint based on hot-spot stress was almost exactly coincided with that of non load-carrying joint based on nominal stress. So we have conducted that the fatigue strength of a welded joint with different geometry from the non stress distribution along the expected crack path.

• Journal of the Korean institute of surface engineering
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• v.34 no.2
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• pp.142-150
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• 2001

Due to naturally formed copper oxides, the adhesion strength between copper and epoxy resin is often very poor. To improve the adhesion strength between copper and epoxy resin, Cu-based leadframe sheets were oxidized in a brown-oxide forming solution. Then the effect of brown-oxide formation on the adhesion strength of leadframe to epoxy molding compound (EMC) was studied using pull-out specimens. After the pull-out test, fracture surfaces were analyzed using SEM, AES and EDS to determine failure path. The results showed that the failure path lay over inside the CuO and inside the EMC irrespective of the pull strength.

• IE interfaces
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• v.11 no.1
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• pp.165-174
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• 1998

This study has empirically analyzed the competitive strategies of the Korean component manufacturers. To differentiate the competitive strategies, the study employed two indexes: degree of support from customer firms and degree of internal innovation process. The performance measures include cost, quality, delivery and flexibility. 115 questionnaires were finally collected from the Korean part manufacturers and used for the final analyses. ANOVA, Chi-squared tests and t-tests were employed for statistical analyses. There are two major findings in this study. First, both internal innovation and external support from customers are equally important to improve manufacturing competitiveness of Korean component manufacturers. Second, strategic path to improve competitiveness of Korean component manufacturers is as follows: focusing on internal innovation ${\rightarrow}$ seeking for formal relationship with customers ${\rightarrow}$ pursuing external support from customers.

• Steel and Composite Structures
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• v.30 no.3
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• pp.253-269
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• 2019

This paper investigates the effects of the tensile catenary action on dynamic increase factor (DIF) in the nonlinear static analysis for progressive collapse of steel-frame buildings. Numerical analyses were performed to verify the accuracy of the empirical and analytical expressions proposed in the literature in cases where the catenary action is activated. For this purpose, nonlinear static and dynamic analyses of a series of steel moment frame buildings with a different number of spans and stories were carried out following the alternate path method. Different column removal scenarios were considered as separate load cases. The dynamic increase factor that approximately compensates for the dynamic effects in the nonlinear static analysis was selected so to match results from the nonlinear dynamic analysis. The study results showed that the many expressions in literature may not work in cases where the catenary stage is fully developed.

• Transactions of Materials Processing
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• v.15 no.6 s.87
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• pp.467-472
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• 2006

The forming limit diagram of tube is required for the part design and the formability analysis of tube hydroforming. The finite element analyses of simple bulge test were done to obtain the various strain combinations on FLC. The finite element analysis results were shown that the bursting at various strain combinations could be induced by simple bulge test. The experiment oi tube bulge test was carried out according to the test condition that obtained from finite element analysis and the left hand side of forming limit diagram was built.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.11A
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• pp.1613-1619
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• 2000

이 논문에서는 전파재널 측정 시스템을 이용하여 건물내 무선 채널의 전파특성인 실효 시간지연 확산과 경로손실을 측정하고 분석한 결과를 제시한다. 구성된 측정 시스템은 미끄럼 상관기를 이용한 대역확산 채널 측정 시스템에서 2 GHz에서 동작하며 3 m 의 분해능을 갖는다. 건물내 무선 채널 특성의 측정환경은 송신 안테나와 수신 안테나가 같은 층에 있을때, 서로 다른 층에 있을때, 그리고 사무실 안에 같이 위치할 때의환경으로구분하여 실험한다.

• Proceedings of the KIEE Conference
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• 1998.07f
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• pp.1879-1881
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• 1998

The conducted differential mode (DM) EMI in a flyback converter are analyzed. Circuit modeling of passive components and PCB pattern for the EMI simulation are presented. Using the model, high frequency noise path is analyzed. The analyses are verified with simulations by identifying the peakings of the EMI pattern.

• Korean Journal of Social Welfare
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• v.56 no.4
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• pp.239-268
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• 2004

This study examined the role of self-construals in marital satisfaction among men and women, and explored how independent and interdependent self-construals contribute to or undermine marital satisfaction. Data were drawn from a self-administered questionnaire study in which 489 married people(aged 25-75) residing in Seoul participated. Path analyses were conducted using Structural Equation Modeling Program, and a goodness of fit of the proposed path model was evaluated. As expected, the positive impact of independent self-construal on marital satisfaction was mediated by self-esteem and clarity of communication, and that of interdependent self-construal on marital satisfaction was mediated by psychological stability and a sense of relational well-being. The direct effects of these two types of self-construal on marital satisfaction were opposite. As predicted, independent self-construal decreased marital satisfaction, whereas interdependent self-construal increased it. All of the direct and indirect effects of independent and interdependent self-construals on marital satisfaction were statistically significant, except the indirect effect of interdependent self-construal as mediated by psychological stability. The goodness of fit indexes of the path model indicated that the model was acceptable. However, the results of separate path analyses for men and women showed that some of the effects of self-construals on marital satisfaction differed by gender. Based on these results, implications for clinical social work practice were discussed.

• Journal of Environmental Science International
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• v.2 no.3
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• pp.161-177
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• 1993

The Yellow Sand Events observed over the Korean peninsula during 22-24 April, 1993 were examined using the synoptic data and GMS visible image to identify the transport path of the Yellow Sand and the main factor governing the duration of the Yellow Sand phenomenon. The 850 hPa convergence chart and the 700 hPa trajectory analyses of the air mass laden with Yellow Sand particles suggested that the Yellow Sand particles observed over Korea were probably transported from the Gobi Desert and the Loess Plateau. The duration of the Yellow Sand Events was about 35-40 hours rather shorter than normal as the high pressure system centered near the Mongolia region moved rapidly toward the Yellow Sea, which drove away the Yellow Sand particles over the Korean peninsula toward the Japan Islands, furthermore the low-level stratification of the air mass over the Korean penishula showed the unstable atmospheric condition leading to atmospheric diffusion of the particles. The trajectory analyses and the GMS visible image indicated that the long-range transport of the air mass laden with the Yellow Sand particles of this case was more dependent on the 700 hPa air flow than on the 850 hPa air flow.