• 한국물환경학회지
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• 제23권3호
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• pp.356-366
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• 2007

In this paper a methodology is developed to prioritize replacement of water distribution pipes according to the economical efficiency of replacement and assess the long-term effects of water main replacement policies on water distribution systems. The methodology is implemented with MATLAB to develop a computer algorithm which is used to apply the methodology to a case study water distribution system. A pipe break prediction model is used to estimate future costs of pipe repair and replacement, and the economically optimal replacement time of a pipe is estimated by obtaining the time at which the present worth of the total costs of repair and replacement is minimum. The equation for estimating the present worth of the total cost is modified to reflect the fact that a pipe can be replaced in between of failure events. The results of the analyses show that about 9.5% of the pipes in the case study system is required to be replaced within the planning horizon. Analyses of the yearly pipe replacement requirements for the case study system are provided along with the compositions of the replacement. The effects of water main replacement policies, for which yearly replacement length scenario and yearly replacement budget scenario are used, during a planning horizon are simulated in terms of the predicted number of pipe failures and the saved repair costs.

• 한국신뢰성학회:학술대회논문집
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• 한국신뢰성학회 2011년도 춘계학술발표대회 논문집
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• pp.319-328
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• 2011

The failure of LCC analysis is recognized as a serious risk for companies in fast-paced business environment. LCC analysis has been mentioned and analyzed only in accounting perspectives, but recently engineering perspectives of LCC analysis based on the execution of appropriate procedures become more important than the accounting perspectives. Especially, the practical use of reliability engineering related methodologies is recognized as a key factor for the LCC analysis. For the practical use of reliability methods, LCC analysis for unexposed problems is a key issue, and utilizing FMEA and FTA techniques is needed to solve the unexposed problems. Reliability, maintainability, availability, and safety should be evaluated by the LCC analysis with the reliability methods, so we study methodologies for the LCC analysis. Present Worth can be calculated by multiplication of Annual Equivalent Cost and PWAF. Reliability engineering related methods are needed for the process of dividing Present Worth into PWAF, and the practical use of reliability methods can improve accuracy of LCC analysis.

• 대한조선학회논문집
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• 제47권2호
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• pp.258-264
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• 2010

Various kinds of ballast water treatment systems (BWTS) have been developed corresponding to reinforced IMO rules for marine environment. Some of them got the certificate of IMO and others are waiting for it. Selection of optimum BWTS is very important. Optimum BWTS means not only functional requirements but also economic efficiency. This paper presents economic analysis model for optimum BWTS according to ship type and size. In this study 10 kinds of BWTS whose initial installation cost and maintenance cost are known are analyzed based on present worth method. It is assumed that all BWTS satisfy minimum functional requirements and we need to consider different economical efficiency. Through the economic analysis we could select optimum BWTS.

• 아동학회지
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• 제10권1호
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• pp.64-78
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• 1989

The present study investigated children's self-perceived competence as related to (1) their perception of parental warmth and control (2) age and sex of child (3) the relationship of this perception to parents' educational level and children's sex. The subjects were 303 fourth and sixth grade children selected from three elementary schools in Seoul. The instruments were a children's self-perceived competence scale, and a perception of parental warmth and control scale. Frequencies, percentiles, mean, t-test, one-way-ANOVA, and $Scheffe{\acute{e}}$-test were used for data analysis. There were significant differences in children's self-perceived competence by perception of parental warmth and control. The children who perceived more parental warmth and control perceived themselves higher in cognitive and social competence and in self-worth. Children whose parents' were college graduates perceived highest parental warmth. Fourth grade children perceived themselves higher than sixth grade children in cognitive competence and in global self-worth. Boys perceived themselves higher than girls in physical competence. Boys perceived higher parental control than girls.

• ETRI Journal
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• 제10권4호
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• pp.146-160
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• 1988

The purpose of the present study is to build a model to determine the structure of long-term quasi-optimal rates of local and toll telephone services. The outline of this study is as follows : Telephone business, providing social goods, is capital-intensive industry which needs huge fixed cost to operate exchanges and telephone networks nationwide. The nature of above industry justifies the market structure of telephone business to be natural monopoly and makes a good reason for government's direct regulation, that is, price regulation. Three is a gap between the present rates and the quasi-optimal ones because some administrative processes intervene in rate making process before execution. On the above diagnostic basis, the present study made an empirical test for the optimality of present rates structure in connection with Ramsey-Boiteux model to maximize the sum of producer's and consumer's surplus and also the current study proposed a qusasi-optimal rates structure for better market performance. From the empirical analysis, we can deduce a policy recommendation the local price should be increased to 47% whereas toll price decreased to 24% in order to improve the net welfare worth of 32.6 billion won.

• 한국심리학회지 : 문화 및 사회문제
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• 제28권3호
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• pp.373-392
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• 2022

본 연구는 Donnelly 등(2016)의 물질주의 추구에 대한 도피이론을 적용하여 대학생의 물질주의 추구 과정을 경험적으로 검증하였다. 도피이론에서 제시된 6단계 중 높은 삶의 기준에 비추어 자신의 부족함을 느끼는 1단계를 외적 자기가치 수반성으로, 부족한 자신을 비난하는 2단계를 실제-이상적 자기 간 불일치로, 자신을 혐오적으로 인식하는 3단계를 낮은 자존감 안정성으로 개념화하였다. 이상의 도피이론 3단계에 따라 외적 자기가치 수반성이 자기불일치와 자존감 안정성을 매개로 물질주의를 예측할 것으로 예상하였다. 가설 확인을 위해 대학생 465명(여 262명)을 대상으로 자기보고식 설문조사를 실시하고 구조방정식 모형을 통해 검증하였다. 연구 결과, 외적 자기가치 수반성과 물질주의 간 관계에서 자기 불일치의 매개효과 및 자기 불일치와 자존감 안정성의 순차적 매개효과가 유의하였다. 물질주의에 대한 외적 자기가치 수반성의 직접효과 또한 유의하게 나타났다. 이 연구는 능력주의 한국사회에서 대학생이 물질을 좇게 되는 과정을 도피이론을 적용하여 경험적으로 밝힌 의의가 있다.

• 복식
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• 제58권6호
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• pp.69-84
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• 2008

Considering that star reflects the image of current society, analyzing fashion of celebrity is to read ideal type and demands of beauty of the era. Especially the rock music-represents youth culture that last on present day-born in 1960's, and it is considered to a significant decade in pop music history. Thus this research will analysis rock star's fashions in iconological view of E. Panofsky. The aim of this document is Clarifying how the fashion of pop stars appeared and what formed its worth. As a result of analyzing fashions of rock star in 1960's, it is available to find these sameness and difference. The Mods borrowed images of the past, and introduce the elite modernism and shows very urban style. The Folky and the Psychedelic showed post-structuralism propensity against industrial society, in the case of the Folky it induced styles that symbolize labor class to realize social worth. And as an aftereffect of war and repulsion of commercial worth, they embody nature-returning peasant look so that it shows pastoral mood in total. The Psychedelic express somewhat struggling escapism and it generated illusionary images with quests to superego and glorification to psychedelic status. The Folky and the Psychedelic are same in the side of introducing existentialism, this occurred by using ethnic factor. But the Folky showed plain outlook by pop propensity, on the other hand, the Psychedelic showed magnificent outlook such as optical art, pop art, and futurism ought to express merrymaking culture. And common feature of these is introduction of unisex mod which is came after the change of gender role. Thus each star or group has professed special ideology into their culture and it is reflected to acts which is including music and dress style. This affair is analyzed like these two things. The mass of people schemes their identity with inducing special ideology to their culture at the first. And the purpose to archive cultural hegemony in inter-social class at the next.

• 품질경영학회지
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• 제22권3호
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• pp.54-65
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• 1994

A hybrid warranty policy for a repairable item is considered. Assuming that minimal repairs ar e performed for failures during warranty period, present worth of warranty cost is derived from a supplier's viewpoint. An optimal preventive periodic replacement policy for the case is also derived from a user's viewpoint Numerical examples are presented in order to explain the results.

• Nuclear Engineering and Technology
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• 제54권3호
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• pp.781-789
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• 2022

KHNP had licensed Dynamic Control rod Reactivity Measurement (DCRM) method using detector current signals of PWRs in 2006. The method has been applied to all PWRs in Korea for about 15 years successfully. However, the original method was inapplicable to PWRs using low-sensitivity integral fission chamber as ex-core detectors because of their pulse pile-up and the nonlinearity of the mean-square voltage at low power region. Therefore, to overcome this disadvantage, a modified method, DCRM-EK, was developed using kinetics behavior after equilibrium condition where the pulse counts maintain the maximum value before pulse pile-up. Overall measurement, analysis procedure, and related computer codes were changed slightly to reflect the site test condition. The new method was applied to a total of 15 control rods of 1000 MWe and 1400 MWe PWRs in Korea with worths in the range of 200 pcm -1200 pcm. The results show the average difference of -0.4% and the maximum difference of 7.1% compared to the design values. Therefore, the new DCRM-EK will be applied to PWRs using low sensitivity integral fission chambers, and also can replace the original DCRM when the evaluation fails by big noises present in current or voltage signals of uncompensated/compensated ion chambers.

• 태양에너지
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• 제10권1호
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• pp.63-79
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• 1990

태양열 주택 및 급탕의 보급 정책은 민수용 에너지의 절감 또는 대체의 의미에서 그 필요성 및 당위성을 인정받고 있으나, 다른 대체에너지와 마찬가지로 태양열 이용시스템의 경제성이 가상 문제가 되고 있는 실정이다. 본 연구에서는 태양열 주택 및 급탕의 경제성을 상세히 분석함으로써 실질적인 보급정책 자료를 제공하며, 실수요자를 위한 계몽근거를 마련하고자 한다. 본 연구에서는 태양열 이용시스템의 경제성을 정확히 수행하기 위한 의사결정지원 시스템(decision support system)을 확립시켰으며, 이에 따른 태양열 이용시스템의 열적성능 해석과 동시에 경제성 분석은 시행오차(trial & error)하에 수행할 수 있도록 각종전산 프로그램을 개발하였다. 태양열 주택 및 급탕의 열적성능 해석은 모의실험을 통하여 기상 조건과의 상관관계를 도출하고 태양열 이용시스템의 추가비용 및 연료가 이용을 현재가 (present worth) 개념으로 적응하여 산출하고, 순익분기 해석법 (break-even point analysis method) 및 수명가 산정법(life-cycle cost analysis method)으로 경제성 분식을 중점적으로 수행하였다.