• 한국경영과학회지
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• 제30권2호
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• pp.63-71
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• 2005

In the field of nuclear reactor safety study, common cause failures (CCFs) became significant contributors to system failure probability and core damage frequency in most Probabilistic risk assessments. However, it is hard to estimate the reliability of such a system, because of the dependency of components caused by CCFs. In order to analyze the system, we propose an analytic method that can find the parameters with lack of raw data. This study adopts the shock model in which the failure probability increases as the shock is cumulated. We use two-step Expectation and Maximization (EM) algorithm to find the unknown parameters. In order to verify the analysis result, we perform the simulation under same environment. This approach might be helpful to build the defensive strategy for the CCFs.

• Structural Engineering and Mechanics
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• 제32권1호
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• pp.55-69
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• 2009

A quasi ideal importance sampling simulation method combined in the conditional expectation is proposed for the structural reliability estimation. The quasi ideal importance sampling joint probability density function (p.d.f.) is so composed on the basis of the ideal importance sampling concept as to be proportional to the conditional failure probability multiplied by the p.d.f. of the sampling variables. The respective marginal p.d.f.s of the ideal importance sampling joint p.d.f. are determined numerically by the simulations and partly by the piecewise integrations. The quasi ideal importance sampling simulations combined in the conditional expectation are executed to estimate the failure probabilities of structures with multiple failure surfaces and it is shown that the proposed method gives accurate estimations efficiently.

• Journal of Communications and Networks
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• 제12권4호
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• pp.317-329
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• 2010

In recent years, many sparse estimation methods, also known as compressed sensing, have been developed. However, most of these methods presume that the measurement matrix is completely known. We develop a new blind maximum likelihood method-the expectation-sparse-maximization (ESpaM) algorithm-for models where the measurement matrix is the product of one unknown and one known matrix. This method is a variant of the expectation-maximization algorithm to deal with the resulting problem that the maximization step is no longer unique. The ESpaM algorithm is justified theoretically. We present as well numerical results for two concrete examples of blind channel identification in digital communications, a doubly-selective channel model and linear time invariant sparse channel model.

• International journal of advanced smart convergence
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• 제9권3호
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• pp.215-220
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• 2020

The purpose of this study is to analyze the structural relationship among expectation value(relational, hedonistic), brand image, brand attitude, continuance viewing intention. The survey subjects to achieve the purpose of this study were selected the 521 YouTube sports contents Viewer in the metropolitan area. Data processing was done with SPSS 23 for frequency analysis, Cronbach's α analysis. Also, AMOS 21 was used for confirmatory factor analysis and structural equation model analysis. The results of the analysis are as follows: First, both relational value and,, hedonistic value had a positive effect on the brand image. Second, both relational value and,, hedonistic value had a positive effect on the brand attitude. Third, both brand image and brand attitudee had a positive effect on the brand attitude.

• International Journal of Advanced Culture Technology
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• 제8권3호
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• pp.275-279
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• 2020

Due to the recent rapid industrialization worldwide, the number of pediatric asthma patients is increasing. And the fine dust containing heavy metals is linked to the characteristics of high toxic lead due to the increase heating in factory operation and automobile driving. It is the reason of arsenic increasing. In the treatment of pediatric asthma patients, drug administration, oral drug entry, and HMPC (Home Management Plan of Care) are used. In this paper, we analyze the relationship between the onset of asthma and the method of prescription for specific childhood asthma in the United States using EM (Expectation Maximization) and MDL (Minimum Description Length) algorithms. And the association is also analyzed by comparing the nature of specific congestion between the past prevalence of digestive asthma and the recent prevalence of environmental pollution.

• 한국초등과학교육학회지:초등과학교육
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• 제23권4호
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• pp.326-331
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• 2004

In this study, the relationships among self-directed learning ability, science teaching efficacy beliefs (personal science teaching efficacy and science teaching outcome expectation), life satisfaction, job satisfaction, and other background variables of elementary school teachers were investigated. A survey was administered to 234 teachers from 25 elementary schools in Jeonju. It was found that self-directed learning ability of the teachers was significantly correlated with their personal science teaching efficacy, science teaching outcome expectation, life satisfaction, job satisfaction, and age. A stepwise multiple regression analysis revealed that personal science teaching efficacy, life satisfaction, science teaching outcome expectation, and age were the significant predictors on their self-directed learning ability.

• 한국조리학회지
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• 제24권2호
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• pp.44-50
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• 2018

This study investigated if and why there are gulfs between expectations and perceived value for usability. The main objectives of this study are as follows: (a) to examine the differences between expectation and perceived value for usability toward an OTA; and (b) to investigate the reason and purpose for customer visits toward an OTAs. By analyzing the distance between expected and the perceived value for the usability, OTAs can then close this distance and then be able to improve the usefulness of their websites. In addition, after investigating previous evaluation problems, that the various factors that are associated with tourism website evaluations, may be downsized to fit a comprehensive model for website evaluations. The results help to close the gap between expectation and perceived value by helping with the websites design, development, implementation, and management of systems. Based on those findings, effective strategies for OTAs marketing and promotional strategies are suggested.

• 가정과삶의질연구
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• 제24권4호
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• pp.11-24
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• 2006

The purpose of this study was to determine if expectation, performance, and disconfirmation are related to consumer satisfaction and behavioral intention. The major findings were as follows: First, among the four dimensions of the medical services, the level of consumer satisfaction was highest with 'doctors' and lowest with 'facilities' while the level of importance was highest with 'doctors' and lowest with 'medical systems' Second, ability to predict behavioral intention can best be improved with regression coefficient weights among the six measures of consumer satisfaction. Third, greater satisfaction was significantly associated with performance and disconfirmation while behavioral intention was significantly associated with expectations, performance, and discoufirmation.

• 가정과삶의질연구
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• 제25권1호
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• pp.145-158
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• 2007

The purpose of this study was to elicit the multi-dimensions of retirement expectations, and explore sub-factors of retirement expectations which predict the possibility of worker's participation to each pre-retirement planning programs. The major findings were as follows: first, this study shows that there are four sub-factors; Imposed frustration, New beginning, Transition to rest, Continuing. And there was a significant difference in retirement expectation according to sex, age, income, and health status. Second, the major affecting factors on participation in pre-retirement planning programs were sex, age, job, educational attainment, and health status. Third, those who have retirement expectations of 'Imposed frustration' tend to attend re-employment, leisure, and health education. Those who have retirement expectations of 'Transition to rest' tend to attend re-employment, inauguration education. And those who have retirement of 'Continuing' tend to attend leisure education.

• 가족자원경영과 정책
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• 제1권2호
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• pp.45-58
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• 1997

The purpose of this study was to test a causal model of employed and unemployed wives on the basis of the family resource management system theory. The data of this study were obtained from 244 wives who lived in Seoul and were financial mangers. Major findings of this study were as follows: 1. Both employed and unemployed wives, knowledge of financial management was significantly predictor of financial planning. That is, household financial mangers with more financial knowlege used more effective planning behaviors than did those financial managers with less financial konwlege. This results emphasize the significance of enhancing the financial konwledge in the household financial management. 2. For unemployed wives, expectation of household’s future financial condition was influenced by age, household income, locus of control over their financial situation, and perception of financial management’s effectiveness. The strongest predictor of expectation of the household’s future financial situation was age. Younger managers were more optimistic about the future. 3. The findings of this study support theoretical framework on the basis of the family resource management system theory, both for employed and unemployed wives.