• Journal of Korean Institute of Industrial Engineers
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• v.24 no.3
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• pp.367-379
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• 1998

This paper considers two modes of partially accelerated life tests for items having Weibull lifetime distributions. In a use-to-acclerated mode each item is first run at use condition and, if it does not fail for a specified time, then it is run at accelerated condition until a predetermined censoring time. In an accelerated-to-use mode each one is first run at accelerated condition and, if it does not fail for a specified time, then it is run at use condition. Maximum likelihood estimators of the parameters of the lifetime distribution at use condition, and the 'acceleration factor' are obtained. The stress change time for each mode is determined to minimize the asymptotic variance of the acceleration factor, and the two modes are compared. For selected values of the design parameters the optimum plans are obtained, and the effects of the incorrect pre-estimates of the design parameters are investigated. Minimizing the generalized asymptotic variance of the estimators of the model parameters is also considered as an optimality criterion.

• The Korean Journal of Health Service Management
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• v.10 no.2
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• pp.83-97
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• 2016

Objectives : This study analyzed the factors that determine the use and type of medical examination services (MES) to develop a model explaining the use behavior of MES which could consequently contribute to policy implications for medical examinations. Methods : Based on Anderson's healthcare utilization model, the MES utilization model was developed by including the perceived needs for MES. The data were collected from an online survey of a population aged 20-39 years and from a telephone survey of a population aged 40 years or older, respectively. Chi-Square tests and hierarchical logistic regression analyses were done with SAS version 9.3. Results : Generally, as health status became lower, the use of MES increased. However, patients with two or more chronic diseases were less likely to use private MES compared to patients with one chronic disease. The perceived needs for MES were only related to the use of service and not to the choice of the MES type. Conclusions : There were different results for the significant determinants between the use of the MES and the choice of the MES type. The healthcare industry needs to aware of consumer needs to provide MES based on empirical findings.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.22
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• pp.10033-10038
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• 2014

The aim of this study was to determine the prevalence of tobacco use, beliefs and risk awareness and psychosocial correlates of tobacco use among university students in 24 low, middle and emerging economy countries. Using anonymous questionnaires, data were collected from 16953 undergraduate university students (mean age 20.9, SD=2.9) from 25 universities in 24 countries across Asia, Africa and the Americas. Results indicate that overall 13.3% of the university students were current tobacco users, 22.4% for men and 6.6% for women, ranging from 3.8% in Singapore to 32.5% in Cameroon. The risk awareness of the smoking lung cancer link was 83.6%, while the risk awareness of the smoking heart disease link was 46.5%. Multivariate logistic regression found that older age, male gender, having a wealthy family background, living in a low income country, residing off campus on their own, poor beliefs in the importance not to smoke, awareness of the smoking heart disease link, hit by a sexual partner, depressive symptoms, and substance use (binge drinking and illicit drug use) were associated with current tobacco use.

• Journal of the Korean Society for information Management
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• v.34 no.1
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• pp.241-262
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• 2017

This study aims to identify and analyze the Twitter use of domestic public libraries. In order to identify the detailed patterns of Twitter use in library and information services, a content analysis was conducted for the 3,038 tweet data from the top 14 public libraries' accounts on Twitter use. Inductive approach was adopted to develop a coding scheme and open coding was conducted with the entire tweet. Additionally, correspondence analysis was conducted for the result of content analysis to identify how library accounts correspond to specific types. As a result, 3 main categories and 9 sub-categories of public libraries' Twitter use were developed. And the 37 detailed patterns of public libraries' use of Twitter were identified. The identified patterns can provide the libraries interested in Twitter use with guidelines.

• Journal of the Korea Convergence Society
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• v.8 no.10
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• pp.53-60
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• 2017

The use of 'Idumunja' for programs is inevitable before Unicode came out. However, even now that Unicode has been established as an international standard in both name and reality, there has been an insistence that the use of Hangeul identifiers should be avoided. This study surveyed the students for the reasons why they prefer to use English identifiers and for the notations that can substitute the function of English capital letters in using Hangeul identifiers. Then, we discussed the vanity of argument that the use of English identifiers is a global trend, and proposed two notations for the use of Korean identifiers. In order to improve the productivity of software, programmer's job satisfaction, and the ease of maintenance, the use of Hangeul identifiers should become rapidly common.

• The Korean Journal of Health Service Management
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• v.8 no.4
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• pp.221-229
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• 2014

Breast cancer is increasing at a remarkable rate in Korea. We investigated the association between oral contraceptive use and breast cancer in Korean women. Using the 5th Korea National Health and Nutrition Examination Survey data, 8,495 women aged over 30 years are analyzed. Furthermore, the data used in this study is obtained using a complex sampling method in order that it is generalized. The previous studies in Korea, were not statistically significant due to the relatively short duration during which oral contraceptives had been available. However, the longer duration of oral contraceptive use exhibits tendency to increase the risk of breast cancer. Women using oral contraceptives, particularly for more than two years have an increased occurrence of breast cancer compared with women who do not use oral contraceptives. This result reflects the late introduction of oral contraceptives in Korea compared with developed countries. The recent increase in interest about the use of oral contraceptives has been increasing for a variety of reasons. Therefore, it is necessary for continuous and specific clinical studies to examine the connections between the first use of oral contraceptives, oral contraceptives use duration, adverse effects of oral contraceptives and breast cancer in order to develop strategies for preventing breast cancer.

• Asian Journal for Public Opinion Research
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• v.1 no.2
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• pp.90-102
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• 2014

By integrating useful insights from social cognitive theory and social capital theory, we aim to develop a model for better understanding people's behaviors related to the use of social networking sites (SNSs) and formalize the role of social capital in individuals' continuous SNS use. Propositions that emphasize the triadic interactive relationships among environmental, personal, and behavioral factors were highlighted in this study. After reviewing previous studies, in this paper we proposed the following: (1) the causation between SNS use and individuals' perceived social capital might be mutual; social capital may not only be the result of media selectivity, but could also be an essential stimulus initiating the start of using SNSs; (2) the influences of SNSs use on the generation of individuals' online social capital might be conditional upon particular patterns of use; (3) both the level of dependence on SNSs and the differentiated patterns of SNSs use vary according to individuals' perceived offline social capital and their personal characteristics, for instance, personality or self-construal, and social anxiety.

• Korean Journal of Childcare and Education
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• v.12 no.4
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• pp.41-69
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• 2016

The purpose of this study is to promote the use of cultural facilities of North Korean refugee mothers with young children by finding out their past experience of cultural facility use. The subjects of this study were 183 North Korean refugee mothers with young children and a total of four research participants. A survey and in-depth interviews were used to draw reliable research results. The research results are as follows: First, as to uses of cultural facilities, North Korean refugee mothers with young children got information about cultural facilities through the Internet community such as Internet cafes and blogs. Their considerations for using cultural facilities were diversity of activity programs and subdivision of performances and arts activities. Over 50% of mothers responded that cultural facilities were needed to enhance the creativity of their children. Second, concerning difficulties of cultural facility use, the most difficulty was high costs, and the second most difficulty was absence of cultural facilities nearby their residence. Third, as to the needs of cultural facility use, a children's library was needed the most for children's development. They responded that the most necessary policy for cultural facility use was to increase cultural vouchers for low-income households and to expand recipients of these vouchers.

• Journal of the Korean Solar Energy Society
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• v.33 no.4
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• pp.59-69
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• 2013

The Consultation about Energy Use Plan is prescribed by the Energy Use Rationalization Act. In order to reset Examination Criteria for Energy Use Plan, consultation case analysis from 2001 to 2010 were carried out and National Energy Master Plan was reviewed. This study proposes that Examination Criteria for Energy Use Plan be should divided into Urban & Tourism complex development project and Industrial complex development project for the prevention of civil complain. Also predicts that effect of energy savings calculated by Reset Examination Criteria on $1^{ST}$ energy demand BAU at 2030 is 2.2%, effect of new & renewable energy utilization at 2030 is 3% and the rate of $CO_2$ reduction to greenhouse gas emission BAU at 2020 is 1.1%.

• Progress in Medical Physics
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• v.29 no.4
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• pp.115-122
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• 2018

Although the current internationally recommended standard for the use factor (U) applied to CyberKnife is 0.05 (5%), the CyberKnife shielding standard is applied more stringently. This study, based on clinical data, was aimed at examining the appropriateness of existing shielding guidelines. Sixty patients treated with G4 CyberKnife were selected. The patients were divided into two groups, according to whether they underwent skull or spine tracking. Based on the results, the use factors for each wall ranged from 0.028 (2.8%) to 0.031 (3.1%) for the intracranial treatment and 0.020 (2.0%) to 0.022 (2.2%) for the body treatment. Excessive barrier thickness resulted in inefficient use of space and higher cost to the institutions. Furthermore, because the use factor is influenced by the position of the robot, the use factor determined based on the clinical data of this study would facilitate more reasonable treatment room design.