• Communications for Statistical Applications and Methods
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• v.11 no.2
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• pp.399-411
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• 2004

A common method of handling nonresponse in sample survey is to delete the cases, which may result in a substantial loss of cases. Thus in certain situation, it is of interest to create a complete set of sample values. In this case, a popular approach is to impute the missing values in the sample by the mean or the median of responders. The difficulty with this method which just replaces each missing value with a single imputed value is that inferences based on the completed dataset underestimate the precision of the inferential procedure. Various suggestions have been made to overcome the difficulty but they might not be appropriate for public-use files where the user has only limited information for about the reasons for nonresponse. In this note, a multiple imputation method is considered to create complete dataset which might be used for all possible inferential procedures without misleading or underestimating the precision.

• Journal of the Korea Safety Management & Science
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• v.10 no.3
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• pp.183-191
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• 2008

Many companies desperately effort to find out more effective management method to survive in keen competition. Jack welch of past GE's CEO had said that an excellent result of today's GE management is thanks to Six sigma work. Many korean companies are introduced Six sigma method in their management since late 1993. Six sigma uses a set of strategies, statistics and methods to improve the processes we use to do everything from designing to manufacturing a product from marketing products and services to providing business information to our internal and external customers. The purpose of this study is to overcome these problems and to help make an important decision in establishing introduction strategy by abstracting the reasons and success factors and result indices which are important sources for introducing Six sigma management.

• The Journal of Information Systems
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• v.20 no.2
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• pp.135-154
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• 2011

The Sido.Saeol system, a local government information system cost too much for having been designed and developed during last four years but the effectiveness of this system is still open to doubt. Also maintenance cost is still too high and become increasing year by year. To find out the reasons and to suggest how to solve these problems, a service quality of an Sido Saeol system and the public servant's job satisfaction were investigated based on the Delone and McLean's updated IS success Model(2003). To investigate of the effectiveness of the Sido Saeol system, 8 variables are analyzed to test 3 main hypothesis. After all the analysis, we found that Sido.Saeol systems have many aspects to be improved for system use and job satisfaction and have to be revise in the aspects of system qualities.

• 한국디지털정책학회:학술대회논문집
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• 2004.05a
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• pp.195-204
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• 2004

Due to growth of diversified media, content screening is the definite procedures. The procedures of screening varies from country by country in various reasons. Therefore, reason of conducting such study is to compare & contrast screening process by countries. In order to clarify definition of terms that measures screening, "censorship" means "legislative filtering process prior to public appearance". In contrary "Rating and/or Classification" is defined opposite of it. After defining these terms, Screening is dignified into two distinctive measures, which are "legislative intereference" and "voluntary notification". Those two measures are again sub-categorized into eight distinctive operational definition. Utilizing those distinctive measures, our study has concluded as US, Japan and some laissez-faire countries use "voluntary notification" systems but in contrast China and Brunei use "legislative filtering" system.? Korea and Australia uses unique combination of both system. In order for Korea to adopt "voluntary notification system", legislative intereference must be weaken and develop strong "voluntary notification" system.

• Journal of the Korean housing association
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• v.26 no.6
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• pp.9-16
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• 2015

The Japanese economy has been unstable since 1990. Economic instability and changes in working conditions have made the acquisition of housing and the improvement in housing standards difficult. Unstable working and habitation conditions have also spread, and the Nagoya Metropolitan Area is recognized as a traction community in the Japanese economy. This study employed existing statistics and helpline consultations in 2013 to clarify the state of housing poverty in the Nagoya Metropolitan Area. Moreover, it clarified the conditions for improvement in the housing standards for the low-income households, a regional gap, and reasons for the deteriorating housing levels of low-income households by investigating the "Housing and Land Survey." Furthermore, it clarified housing difficulties that do not appear in existing statistics by investigating the examples of "toll-free call consultations" in 2013.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2001.11a
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• pp.58-63
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• 2001

Recently, it has been often reported that recycling of wasted glasses should be a great topic in related business circles. For the environmental reasons, a public institution are looking fur the ways of recycling these waste glasses. Consequently, the purpose of this research is to recycle crushed and powdered waste glasses by substituting for the cement in mortar and concrete. First of all, the optimum replacement ratio of Powdered Waste Glasses(PWG) can be obtained from the pilot test results. Secondary, we make advances in recycling of waste glasses as recycled to make secondary concrete products. So, we manufactured concrete brick and block contained powdered waste glasses by through mortar pilot test.

• The Journal of Information Technology and Database
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• v.8 no.2
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• pp.61-69
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• 2001

System Integration Projects, especially in public sector, have a tendency of growing in size and duration. Under such environment the effects of IT personnel turnover becomes a serious problem. In addition a high rate of turnover hinders shill accumulation and competitiveness obtainment. In this research we explored the reasons of turnover by way of tracing IT personnel who have involved in large-scale SI projects and moved or quit before the completion of the projects. Based on previous research we identified three dimensions of variables that affected turnover : task-related dimension, human relations dimension, treatment-related dimension. We used these dimensions as a guideline for the interview and questioning exploration. Implications from the research for improving IT Personnel management are also elaborated.

• Proceedings of the Korea Concrete Institute Conference
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• 1998.04a
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• pp.285-291
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• 1998

During recent years, the durability of concrete structures has been considered in concret practice and material research. To preserve the brittleness of concrete as well as energy absorption and impact resistance, amount of fiber usage has greatly increased in the field of public works. Ultra fine powder, silica fume, mixed into concrete, it reduce void of concrete structure. Especially, there's a great effect for strength improvement of concrete by initial pozzolanic reactions. For these reasons, if silica fume mixed into concrete, it decrease the total void by microfilter effect . Pozzolan reaction, between cement particle and silica powder, can elaborate the micro structure of matrix. And so, in this paper, we deal SFRC for the purpose of efficiently using of industrial by-products(silica fume). Also we performed the test for durability such as freeze-thaw resistance and accelerated carbonation of SFRC using silica fume.

• Journal of the Korea Safety Management & Science
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• v.16 no.1
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• pp.45-52
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• 2014

The purpose of this study is to make sure what the stress causes of women's EMTs within the firehouse are, and is to suggest ideas (plans) that are possible to resolve this problem. The reasons are because of difficulties such as not only the overwork at one's tasks, the uncomfortable working environment and circumstances, women's pregnancy, but also shift work or the shift system. It's own ideas about the way to resolve these difficulties are as follows: a separate operation of first-aid department, environmental improvement within a fire house (fire station) via remodeling, activation of substitute man power, alterating women's EMT services into daywork system, mutual encouragement and solicitude among co-workers, reinforcement of the number of the working force to be mobilized, and adoption about the rest year system in employment.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.1248-1253
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• 2007

Urban transit or subway stations generally service for a long period of several decades. And, the urban transit or subway is public transportation which lots of people takes every day. During the service time, they are inevitably damaged from environmental corrosion, material aging, fatigue, and the coupling effects with long-term loads and extreme loads. The included damage accumulates and performance degenerates due to the above factors. They would inevitably reduce the resisting capacity of station against the disaster; even they result in collapse with the structural failure under extreme loads. And, if disaster such as earthquake, fire, etc. happens, it causes huge property damage and threatens the human lives. Because of these above reasons, the intelligent health surveillance system should be researched and developed for ensuring the safety of station. In this paper, the research plans of the intelligent health surveillance system of urban transit station are presented. And also, the development or establishment directions of this system are suggested.