• 방사성폐기물학회지
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• 제8권2호
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• pp.123-133
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• 2010

방사성핵종의 분포유형에 관한 정보에 기초하여 극저준위폐기물의 자체처분 적합성을 통계학적으로 해석할 수 있는 방법론을 개발하였다. 방사성핵종의 분포에 관한 정보를 알 수 없는 경우에 대해서는 널리 알려진 마코프 부등식과 체비셰프 부등식을 적용하여 방사능농도의 산술평균과 허용되는 최대 표준편차의 상관관계식을 제시하였고, 방사성핵종의 농도가 정규분포 또는 로그정규분포를 갖는 경우에 대해서는 확률밀도함수, 누적확률밀도함수 등의 통계학적 관계식을 이용하여 방사능농도의 산술평균과 허용되는 최대 표준편차의 상관관계식을 새롭게 유도하였다. 또한, 자체처분기준 100 Bq/g 및 신뢰수준 95%인 조건에 대한 사례 적용연구를 통하여 방사능농도의 산술평균과 허용되는 표준편차의 범위를 방사성핵종의 분포유형에 따라 정량적으로 비교 제시하고, 자체처분 대상 폐기물의 방사성핵종 분포유형에 관한 정보가 확보될 경우 동일한 신뢰수준에서 자체처분이 허용될 수 있는 범위가 확장될 수 있음을 통계학적으로 입증하였다.

• 유통과학연구
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• 제20권3호
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• pp.59-69
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• 2022

Purpose: The purpose of this study is to provide information for other journals as well as the continuous development of distribution science research by confirming the globalization performance of the Journal of Distribution Science (JDS), the main journal of KODISA. Research Design, Data, and Methodology: A total of 863 papers published in JDS from 2011 to 2021 searched by scienceON were divided into 4 periods and analyzed under the headings of submission system, standardity, collaboration, and degree of achievement of publication goals. SPSS 24.0 and R 4.1.1 package were used to perform the publication frequency analysis, crosstab-analysis, keyword frequency analysis, and LDA topic modeling were performed. In addition, trend analysis with weight applied to each word was performed. Results: It was found that the ratio of English-written papers, which is the indicator of a journal's starndardity, is continuously increasing, and the ratio of overseas authors, which is the indicator of collaboration, is also continuously increasing. It was confirmed through keyword trend analysis by period and LDA topic modeling results - which were weighted to confirm the degree of achievement of the journal's publication goal - that the articles published by the journal has been in agreement with monthly research topic proposed by JDS. Conclusion: By examining the five criteria for globalization, it can be concluded that JDS's efforts for globalization are achieving significant results and providing effective directions for other academic journals. However, in order for JDS to become a top academic journal, it was suggested that efforts should be made to establish a system for collaborative research by domestic and foreign authors, as well as to provide a clear definition for the monthly research topics and classification of sub-topics.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1992년도 하계학술대회 논문집 B
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• pp.779-783
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• 1992

In recent years, it is strongly required to supply high quality electrical power without insulation failure in distribution power cables. Therefore the exact measurement and judgment ar out deterioration degree of cables are essential to increase that supplying reliability. This paper will introduce various diagnostic methods of off-line and live-line cables also propose the judgement criteria and newly trend of diagnostic technique at present.

• International Journal of Reliability and Applications
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• 제12권1호
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• pp.41-48
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• 2011

This paper considers the maintenance model suggested by Jung and Park (2010) to adopt the Bayesian approach and obtain an optimal replacement policy following the expiration of NFRRW. As the criteria to determine the optimal maintenance period, we use the expected cost during the life cycle of the system. When the failure times are assumed to follow a Weibull distribution with unknown parameters, we propose an optimal maintenance policy based on the Bayesian approach. Also, we describe the revision of uncertainty about parameters in the light of data observed. Some numerical examples are presented for illustrative purpose.

• Journal of the Korean Statistical Society
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• 제20권2호
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• pp.99-107
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• 1991

Behrens-Fisher problem is viewed from a model selection approach. Normal distribution is regarded as an approximating model, A criterion, called TIC, is derived and is compared with selection criteria such as AIC and a bootstrap estimator. Stochastic approximation is used since no closed form expression is available for the bootstrap estimator.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1997년도 춘계학술발표회논문집(1)
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• pp.335-341
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• 1997

The generic analysis method for core flow instability is suggested to confirm that the core flow instability would not occur on PWR conditions. For the confirmation, the stability criteria of each fuel type are provided. Instability investigations in various accident conditions prove that the locked rotor accident is the most limiting case to instability. Parametric Effects are surveyed and in good agreement with available studies. The effects of heat flux distribution become negligible as the subcooling number is decreased. The power margin to instability is calculated quantitatively in various accident conditions.

• Communications for Statistical Applications and Methods
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• 제8권3호
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• pp.589-601
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• 2001

Probabilities of overfilling for model selection criteria are derived for several different situations. First, one candidate model with one extra variable is compared to the current model. This is expanded to m candidate models. We show that these comparisons are not independent and discuss ovefitting probabilities. Correlation between two F-tests is derived. Finally, probabilities are computed using the dependent F distributions and F distributions based on order statistics of independent Chi-squares.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 추계학술대회 논문집 전력기술부문
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• pp.185-188
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• 2001

This paper represents planning rules which specify the technical and design criteria and procedures that apply to the transmission asset owner(TAO) and the distribution network service providers(DNSP) in the planning and development of the electricity network.

• 유통과학연구
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• 제3권1호
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• pp.43-67
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• 2005

Recently retail market has been rapidly expanded in the large cities of in Korea and the competition among individual companies in retail market is also being increased. Tenant MD of mixing is one of the most important factor for the company to continuously operate or to fail. The aim of this study is to examine the processes of systematically evaluating the merchandising of the established companies in retail market a part of chain operation in discount store. The basic problem of decision making in general and tenant MD of mixing in particular is to choose a best one in a set of competing alternatives that are evaluated under conflicting criteria. The purpose of research of a paper carries out a duty searching examination with making a tenant MD include by retail research, simultaneously defined when I will show an example for the tenant mix of the profitability side of the domestic discount store market which is tenant MD importance proposing the existing problem arrangement by chain operation management, and is intensifying - tenant MD of standardization in discount store of T-company.

• 한국가시화정보학회지
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• 제19권1호
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• pp.94-99
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• 2021

In order to increase the efficiency of thermoelectric refrigerators using the Peltier effect, it is necessary to optimize the distribution of the flow of cold air from the fan. In this study, the flow flowing upwards and downwards while changing the area of the flow path was visualized using the PIV technique for the control of cold air in a thermoelectric refrigerator. From these results, the flow rate according to the change in the area of the flow path was confirmed, and design criteria for optimizing the distribution of cold air flowing to the top and bottom of the refrigerator were suggested.