• 에너지공학
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• 제12권2호
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• pp.93-100
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• 2003

An estimation methodology of the mass and energy (M/E) release due to the main steam line break (MSLB) has been developed with the RETRAN-3D code. In the case of equipment qualification (EQ), the over-estimated temperature would exceed the design limits of some cables or valves. In order to have a more flexible EQ profiles from the MSLB M/E release, the methodology with the best-estimated code was used. The major conditions affecting the MSLB M/E were found to be the initial SG level, heat transfer between primary and secondary sides, power level, operable protection system, main or auxiliary feedwater availability, and break conditions. The RETRAN-3D models were developed for the Kori unit 1 (KRN-1) which is typical two loop Westinghouse (WH) designed plant. Particularly, a detailed model of the steam generators was developed to estimate a more realistic two-phase heat transfer effect of the steam flow. After the modeling, the methodology has been developed through the sensitivity analyses. The M/E release data generated from the analyses have been used as the input to the inside containment pressure and temperature (P/T) analysis. According to the results at the point of view containment P/T, the Kori unit 1 can have more margin of 5∼15 ㎪ in pressure and 8∼15$^{\circ}C$ in temperature.

• 한국안전학회지
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• 제32권5호
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• pp.115-121
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• 2017

This paper is to introduce the main modeling assumptions and data structures associated with right-censored data to describe the successful methodological ideas for analyzing such a field-failure-data when components operating in different environments. The Kaplan - Meier method is the most popular method used for survival analysis. Together with the log-rank test, it may provide us with an opportunity to estimate survival probabilities and to compare survival between groups. An important advantage of the Kaplan - Meier curve is that the method can take into account some types of censored data, particularly right-censoring. The above non-parametric method was used to verify the equality of parts life used in different environments. After that, we performed the life distribution analysis using the parametric method. We simulated data from three distributions: exponential, normal, and Weibull. This allowed us to compare the results of the estimates to the known true values and to quantify the reliability indices. Here we used the Akaike information criterion to find a suitable life time distribution. If the Akaike information criterion is the smallest, the best model of failure data is presented. In this paper, no-nparametrics and parametrics methods are analyzed using R program which is a popular statistical program.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2003년도 학술.기술논문 발표회
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• pp.125-128
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• 2003

This study aims to feasibility study of the Youth Center. Welfare of adolescents is appeared to a matter of concern and interest as social problems of various kinds related adolescents including the fire at a beer bar in Inchon occur recently. In view of government, in addition to fairness of facility location, location of such facilities arc to be determined the respect to cost of locating facilities and developmental direction in the future. A feasibility study is and effective tool in determining the decision of investment or not and the level of investment priority on projects requiring a sizeable investment and the feasibility of a project. The first, it is to select reasonable location. It was selected three and two by consideration of facilities distribution and connection with others. Five proposal selected was estimated by five element of approach, demand, symbol, reality, environment. In result proposal I was chosen. The next, it is to estimate scales. It was estimated by analysis of catchment area, similar facilities, programs, in result 7,260㎡ come into analysis to the best gross area. The finally, it is to study on economical efficiency. Income Statement estimated was came out ₩1,7billion. in addition, it offer various benefit by public facilities.

• 디자인학연구
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• 제14권1호
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• pp.93-101
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• 2001

This study suggested how to apply it decision-making of product development rapidly by design evaluation process to objectify and the result to quantify with viewpoint of design evaluation sets to marketability. Coverage of this method limited to the evaluation stage of design concept. The procedure of study, first of all, referred to some type of design evaluation method and their feature. And next, referred to some kinds of demand forecasting for marketing. Above an, this study focused on the method of demand forecasting by buying intentions surveys proper to the marketability evaluation of new product design. On a case study, I had investigated preference survey and buying intentions surveys about the design proposal of "language master audio". I selected the best design proposal through the conjoint analysis and also investigated demand forecasting. First, on the basis of buying intentions surveys, choose population and had produced buying demand, awareness demand, potential demand. I could estimate some profit to take out expense and cost from the buying demand. This estimated profit is marketability judgement data of product design at the design concept stage and can be utilized to measurable data for decision-making of product development. Through the case study, this method could forecast a target demand, and even if it is some difference between real sales volume, but the case study could verified that this method is effective to the evaluation of marketability in case of completely new product got on the typical category and the product category could be set up the population clearly.

• 비파괴검사학회지
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• 제23권2호
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• pp.125-132
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• 2003

전자파 레이더 주파수변화에 의한 콘크리트내 층간 연속공동의 시뮬레이션 해석을 위한 모델을 제안하였다. 본 모델에서는 각 전기적 성질이 다른 다층 경계조건 하에서 전자파 레이더의 주파수 변화에 따른 분해능과 감쇠특성이 검토되었다. 이는 계산에 의한 모의 레이더 응답으로부터 콘크리트내 공동의 검출이 가능한 공동 두께의 한계와 최적주파수를 선정하고, 나아가 대상물체의 경계조건별 레이더의 전파한계를 구하는 데 유용하게 이용하기 위한 것이다. 본 모델에 의해 계산된 결과는 콘볼루션기법을 이용한 신호처리에 의해 레이더 화상으로 나타내었다.

• 보건행정학회지
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• 제12권2호
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• pp.1-22
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• 2002

Since the early 1980s scholars have applied latent structure and other type of finite mixture models from various academic fields. Although the merits of finite mixture model are well documented, the attempt to apply the mixture model to medical service has been relatively rare. The researchers aim to try to fill this gap by introducing finite mixture model and segmenting inpatients DB from one general hospital. In section 2 finite mixture models are compared with clustering, chi-square analysis, and discriminant analysis based on Wedel and Kamakura(2000)'s segmentation methodology schemata. The mixture model shows the optimal segments number and fuzzy classification for each observation by EM(expectation-maximization algorism). The finite mixture model is to unfix the sample, to Identify the groups, and to estimate the parameters of the density function underlying the observed data within each group. In section 3 and 4 we illustrate results of segmenting 4510 patients data including menial and ratio scales. And then, we show AHP can be identify the attractiveness of each segment, in which the decision maker can select the best target segment.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2003년도 학술.기술논문발표회
• /
• pp.125-128
• /
• 2003

This study aims to feasibility study of the Youth Center. Welfare of adolescents is appeared to a matter of concern and interest as social problems of various kinds related adolescents including the fire at a beer bar in Inchon occur recently. In view of government, in addition to fairness of facility location, location of such facilities are to be determined the respect to cost of locating facilities and developmental direction in the future. A feasibility study is an effective tool in determining the decision of investment or not and the level of investment priority on projects requiring a sizeable investment and the feasibility of a project. The first, it is to select reasonable location. It was selected three and two by consideration of facilities distribution and connection with others. Five proposal selected was estimated by five element of approach, demand, symbol, reality, environment. In result proposal I was chosen. The next, it is to estimate scales. It was estimated by analysis of catchment area, similar facilities, programs, in result 7,260$m^2$ cone into analysis to the best gross area The finally, it is to study on economical efficiency. Income Statement estimated was came out \1.7billion. in addition, it offer various benefit by public facilities.

• 한국지열·수열에너지학회논문집
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• 제8권1호
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• pp.21-31
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• 2012

This paper reviewed and evaluated some of the commonly used prediction models for thermal conductivity of soils with the experimental data. Semi-theoretical models for two-component materials were found inappropriate to estimate the thermal conductivity of dry state soils. It came out that the model developed by Cote and Konrad gave the best overall prediction results for unsaturated soils available in the literature. However, it still needs to be improved to cover a wider range of soil types and degrees of saturation. In the present study, parametric analysis is also conducted to investigate the effect of soil type and moisture content on the horizontal ground heat exchanger design. The analysis shows that horizontal ground heat exchanger pipe length is reduced with the increase of soil thermal conductivity and water content. The calculation results also show that horizontal ground heat exchanger size can be reduced to a certain extent by using backfilling material with a higher thermal conductivity of solid particles.

• Nuclear Engineering and Technology
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• 제33권6호
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• pp.638-651
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• 2001

The present study is to assess the applicability of the best-estimate thermal-hydraulic code, MARS 1.4, for the analysis of thermal-hydraulic behavior in PWRs during natural circulation conditions. The code simulates a natural circulation test, BETHSY test 4. la, which was conducted on the integral test facility of BETHSY. The test represented the cooling states of the primary cooling system under single-phase natural circulation, two-phase natural circulation and the reflux condensation mode with conditions corresponding to the residual power, 2% of the rated core power value and 6.8 MPa at the secondary system. Based on MARS 1.4 calculations, the major thermal-hydraulic behaviors during natural circulation are evaluated and the differences between the experimental data and calculated results are identified. The calculated results show generally good behavior with regard to the experimental results; the region of single-phase natural circulation is 100-92% of the initial mass inventory, two-phase natural circulation is 84-63 %, and the reflux condensation mode occurred below 58 %. U-tubes empty and the core uncovery are obtained at 39 % and 34 % of the initial mass inventory, respectively.

• Structural Engineering and Mechanics
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• 제44권4호
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• pp.449-463
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• 2012

For buildings subjected to blast loading, structural failure can be categorized into local failure (direct blast effects) and progressive collapse (consequential effects). In direct blast effects, the intensive blast pressures create localized failure of structural elements such as exterior columns and walls. Columns, and their behaviour, play a key role in these situations. Therefore investigating the behaviour of columns under blast loading is very important to estimate the strength, safety and reliability of the whole structure. When a building is subjected to blast loading, it experiences huge loading pressures and undergoes great displacement and plastic behaviour. In order to study the behaviour of an element under blast loading, in addition to elastic properties of materials, plastic and elastic-plastic properties of materials and sections are needed. In this paper, using analytical studies and nonlinear time-history analysis by Ansys software, the effects of shape of column sections and boundary conditions, on behaviour and local failure of steel columns under blast load are studied. This study identifies the importance of elastic-plastic properties of sections and proposes criteria for choosing the best section and boundary conditions for columns to resist blast loading.