• Journal of the Korean Data and Information Science Society
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• v.5 no.2
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• pp.87-94
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• 1994

In this paper, we consider optimum plan to determine stress change times under the three-step stress PALTs, assuming that each test units follows an exponential distribution. The tampered random variable(TRV) model for the three-step stress PALTs setup are introduced, and maximum likelihood estimators(MLEs) of the failure rate and the acceleration factors are obtained. The change times to minimize the generalized asymptotic variance(GAVR) of MLEs of the failure rate and the acceleration factors are proposed for the three-step stress PALTs.

• International Journal of Internet, Broadcasting and Communication
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• v.12 no.1
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• pp.104-110
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• 2020

In the 4th Industrial Revolution, the competitiveness of the software industry is important, and as a solution to fundamentally secure the competitiveness of the software industry, education classes should be provided to educate high quality software personnel in educational institutions. Despite this social situation, software-related classes in universities are largely composed of competitive or individual learning structures. Cooperative learning is a learning model that can complement the problems of competitive and individual learning. Cooperative learning is more effective in improving academic achievement than individual or competitive learning. In addition, most learners have the advantage of having a more desirable self-image by having a successful experience. In this paper, we apply a pair check model, which is a type of cooperative learning, in operating system classes. In addition, the class procedure and instruction plan are designed to apply the pair check model. We analyze the test results to analyze the performance of the cooperative learning model.

• Journal of Korean Institute of Industrial Engineers
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• v.17 no.1
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• pp.95-108
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• 1991

For the case where the lifetime at a constant stress level has exponential distribution, optimal accelerated life test plans are developed under the assumptions of intermittent inspection and Type I censoring. In a optimal plan, the low and high stress levels, the proportion of test units allocated and the inspection times at each stress are determined such that the asymptotic variance of the maximum likelihood estimator of logarithmic transformed mean at the use condition is minimized. In addition to the optimal plan in which numerical technique to solve the set of nonlinear equations must be employed to determine inspection times at each stress level, we also propose another plans which employ equally-spaced or equal probability inspection schemes at two overstress levels of corresponding optimal one. For both optimal and proposed plans, computational results indicate that the asymptotic variance of the estimated mean at the use stress is insensitive to number of inspections at overstress levels for the range of parameter values considered.

• Journal of Korean Institute of Industrial Engineers
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• v.41 no.2
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• pp.144-149
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• 2015

In this study, the effective technology readiness assessment (TRA) method for system development project is suggested. We analyze the domestic and foreign TRA practice and derive the new idea to resolve the problems found from the analysis. Domestic and foreign organizations develop and use checklist for the precise TRA, but the checklist has some problems in type of questions and analysis of assessment. TRA method using the original TRL definition or the checklist should be selected depending on the project characteristic. Questions of the checklist should be classified into critical or non-critical according to their importance. Finally, Test and evaluation master plan (TEMP) in system engineering process can provide an obvious criteria to assess technology readiness level (TRL) of critical technology elements (CTE) composing the system.

• Journal of the Korean Data and Information Science Society
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• v.26 no.1
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• pp.271-280
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• 2015

In this paper, the maximum likelihood estimators for parameters are derived under three step-stress accelerated life tests for Type-I hybrid censored data. The exponential distribution and the cumulative exposure model are considered based on the assumption that a log quadratic relationship exits between stress and the mean lifetime ${\theta}$. The test plan to search optimal stress change times minimizing the asymptotic variance of maximum likelihood estimators are presented. A numerical example to illustrate the proposed inferential procedures and some simulation results to investigate the sensitivity of the optimal stress change times by the guessed parameters are given.

• Journal of Families and Better Life
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• v.28 no.5
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• pp.101-111
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• 2010

The purpose of this study was to develop a standardized scale to diagnostic life planning in late adolescence. A preliminary 32 item scale was developed through a literature review & a survey. 896 people responded to an online survey using the preliminary scale. A series of test, such as test-retest, item-to-total correlation, factor analysis and Cronbach' ${\alpha}$ reliability were conducted using the survey data and a scale comprising 31 items was constructed finally. The diagnostic scale for life planning in late Adolescence consisted of seven factors : (1) complete growth minds (2) life- plan (3) variety experiences (4) close relationships (5) management of healthy body (6) practical finance-plans (7) active preparation of future job. The scale is useful as a guideline for managing life of the late Adolescence. And it is helpful to them to make plan for the better life.

• Journal of the Korean Data and Information Science Society
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• v.21 no.5
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• pp.945-950
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• 2010

As the U.S. Congress has continued to debate over the health care reform pushed by President Obama, there is an ample reason to believe that the systematic risk of the health care industry, especially health care plan providers, is increasing. This study measures and compares the systematic risk of two health care industry indexes and one portfolio of health care plan providers from before and after the introduction of the health care legislation into Congress in September, 2009. The Capital Asset Pricing Model (CAPM) is used to measure the systematic risk, and a dummy variable approach and the Chow test are used to formally compare the systematic risk from before and after the introduction of the legislation.

• Proceedings of the KIEE Conference
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• 2002.07c
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• pp.1804-1806
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• 2002

KEPCO has a plan to operate 765kV electric power network from June, 2001, by the KEPCO's plan. We have developed the extra-high voltage class equipments for 765kV substation. Inpecial, we have proceeded the developments of 800kV Gas Insulated Switchgear from January 1998 to now. Until now we completed the test of a general characteric tests of GIS, the short-circuit test of GCB. DS. ES. HSGS.

• Korean Journal of Computational Design and Engineering
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• v.19 no.4
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• pp.402-409
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• 2014

Presented in this paper is a scheduling method for semiconductor backend process considering the backward pegging. It is known that the pegging for frontend is a process of labeling WIP lots for target order which is specified by due date, quantity, and product specifications including customer information. As a result, it gives the release plan to meet the out target considering current WIP. However, the semiconductor backend process includes the multichip package and test operation for the product bin portion. Therefore, backward pegging method for frontend can't give the release plan for backend process in semiconductor. In this paper, we suggest backward pegging method considering the characteristics of multichip package and test operation in backend process. And we describe the backward pegging problem using the examples.

• Journal of Families and Better Life
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• v.1 no.2
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• pp.1-20
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• 1983

The purpose of this study is to analyze the planning dimensions according to homemaker's age and education. In this study the dimensions of planning are participation, time span , significance, specifity and flexibly. The subject areas of planning are family economy, household activities, child rearing and purchasing. Questionnaires were given to the selected 181 homemakers living in Seoul and Incheon. Data were analyzed by frequency, percent, x2 -test, F-test. The result are as follows: 1) There are significant differences in planning dimensions according to homemaker's age and education in some subject areas. 2)The younger the homemaker is and the higher her educational level is, the more cooperatively the couple plan in family life. 3)The family of which homemaker is younger and more educational tends to plan significantly, specifically and flexibly in family life.