• Nuclear Engineering and Technology
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• 제46권4호
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• pp.481-488
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• 2014

An analysis of the uncertainty quantification related to LBLOCA using the Monte-Carlo calculation has been performed and compared with the tolerance level determined by the Wilks' formula. The uncertainty range and distribution of each input parameter associated with the LOCA phenomena were determined based on previous PIRT results and documentation during the BEMUSE project. Calulations were conducted on 3,500 cases within a 2-week CPU time on a 14-PC cluster system. The Monte-Carlo exercise shows that the 95% upper limit PCT value can be obtained well, with a 95% confidence level using the Wilks' formula, although we have to endure a 5% risk of PCT under-prediction. The results also show that the statistical fluctuation of the limit value using Wilks' first-order is as large as the uncertainty value itself. It is therefore desirable to increase the order of the Wilks' formula to be higher than the second-order to estimate the reliable safety margin of the design features. It is also shown that, with its ever increasing computational capability, the Monte-Carlo method is accessible for a nuclear power plant safety analysis within a realistic time frame.

• 센서학회지
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• 제23권5호
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• pp.299-304
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• 2014

Optimizing the performance of a composite sensor array is necessary when the number of sensors to choose from is large. In this paper, we present a chemical sensors array optimization method using Wilks Lamda algorithm applicable a device to detect low concentration of alcohol from driver's exhale breath for interlocking engine ignition preventing drink-driving. More than 20 chemical sensors fabricated different synthetic stuffs and heater temperatures by collaborators were nominated, 5 sensors were selected for optimal sensors array using the method, and alcohol samples were well discriminated from the interference gases inside the vehicle. It has been confirmed by Principal Component Analysis (PCA).

• 동아시아식생활학회지
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• 제15권4호
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• pp.475-482
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• 2005

As Korea has approached the aging society, older Koreans have become an important force in restaurant sales today. To succeed with this silver market, it is important for restaurant managers to know who they are and which factor influence the older Koreans' eating-out decision making process. The purpose of this study was to investigate the effect of the elderly consumers financial independency on restaurant selection process. Data were collected from 178 older consumers above 55 years old and analyzed using the descriptive statistic analysis, MANOVA, and one-way ANOVA. The results showed that the elderly consumers financial independency significantly influenced the decision making process in determining where they eat out Significant differences were found between high income group and low income group in the Problem Recognition Step(Wilks' Lambda=0.776, F=3.796), Information Search Step(Wilks' Lambda=0.779, F=2.959), Alternative Evaluation Step (I :Wilks' Lambda=0.835, F=1.748/ II :Wilks' Lambda=0.764, F=3.212), and Purchase Decision Step(Wilks' Lambda=0.849, F=2.412), except the Post-Purchase Behavior(Wilks' Lambda=0.933, F=1.179). The more financially independent older consumers were, the more directly they were involved in the eating out decision making process. Older consumers with higher income and more personal property were likely to 'propose to eat out by themselves'(F=10.986), to obtain restaurant information from the 'printed materials'(F=9.707), to consider 'convenient location' as most important factor when they eat out(F=5.594), and to go to 'family restaurant'(F=7.067), 'Japanese restaurant'(F=7.391) and 'fine dining restaurants'(F-=6.382). In conclusion, we found that the elderly consumers financial independency did influence the eating-out decision making process. Considering that older Korean will become a financially independent consumer and will be eating away from home more often, food service operations should actively position themselves for this market and develop the market-driven menus and services to meet their needs and expectations.

• 센서학회지
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• 제24권4호
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• pp.258-263
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• 2015

In order to prevent drink-driving by detecting concentration of alcohol from driver's exhale breath, twenty chemical sensors fabricated. The one of purposes for sensor array which consists of those sensors is to discriminate between target gas(alcohol) and interference gases($CH_3CH_2OH$, CO, NOx, Toluene, and Xylene). Wilks's lambda was presented to achieve above purpose and optimal sensors were selected using the method. In this paper, step-wise sensor elimination based on Euclidean distance was investigated for selecting optimal sensors and compared with a result of Wilks's lambda method. The selectivity and sensitivity of sensor array were used for comparing performance of sensor array as a result of two methods. The data acquired from selected sensor were analyzed by pattern analysis methods, principal component analysis and Sammon's mapping to analyze cluster tendency in the low space (2D). The sensor array by stepwise sensor elimination method had a better sensitivity and selectivity compared to a result of Wilks's lambda method.

• 한국식생활문화학회지
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• 제20권6호
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• pp.638-643
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• 2005

As Korea has approached the aging society, older Koreans have become an important force in restaurant sales today. To succeed with this silver market, it is important for restaurant managers to know who they are and what factors influence older Koreans' eating-out decision making process. The purpose of this study was to investigate the effect of the silver consumers' education level on eating-out decision making process. Data were collected from 178 older consumers above 55 years old and analyzed using the descriptive statistic analysis, MANOVA, and one-way ANOVA. The results showed that the elderly consumers' education level significantly influenced the decision making process in determining where to eat out. Significant differences were found in the Problem Recognition Step(Wilks' Lambda=0.817, F=2.991), Information Search Step(Wilks' Lambda=0828, F=2.218), Alternative Evaluation Step II(Wilks' Lambda=0.741, F=3.596), Purchase Decision Step(Wilks' Lambda=0.859, F=2.223), and the Post-Purchase Behavior(Wilks' Lambda=0.885, F=1.780). The higher education level was, the more directly involved in the eating out decision process. The elderly consumers with university education were likely to 'propose to eat out by themselves'(F=9.346), to obtain restaurant information from the 'printed materials'(F=7.452), to go to 'family restaurant'(F=9.057), 'Japanese restaurant'(F=8.7891) and 'fine dining restaurants'(F=3.936), and to directly express their emotion when they had complaints about restaurant service(F=3.206). In conclusion, older Koreans will become more healthy and wealthy which means the dining out activity will be an important part of their life to socialize with people. Therefore, food service operations should consider the elderly consumers' needs and expectation of restaurant services and actively position themselves for this new market segment.

• 한국산학기술학회논문지
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• 제15권2호
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• pp.979-988
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• 2014

본 연구는 간호사들이 인식한 안전 분위기와 업무환경을 포함한 조직의 특성과 투약오류보고장애요인간의 관련성을 검증하기 위한 연구이다. 수정된 안전 분위기, 업무환경, 투약오류보고장애 문항을 활용하여 7개 병원의 334명의 간호사들을 대상으로 하여 조사하였다. 자료수집기간은 2012년 9월 한달 간이었고, 서술적 통계, Pearson correlation coefficient, canonical correlation을 적용하였다. 조직의 특성은 투약오류보고장애와 세 가지 유의한 상관이 있었다. 첫 번째 정준상관계수는 .50(Wilks' ${\lambda}$=0.61, df=32, p<.001)이었고, 두 번째는 .35(Wilks' ${\lambda}$=0.81, df=21, p<.001), 세 번째는 .22(Wilks' ${\lambda}$=0.93, df=12, p=.018)이었다. 첫 번째 정준상관은 높은 안전 분위기와 업무환경이 오류보고에의 두려움을 제외한 투약오류보고와 관련이 있었다. 두 번째 식은 '의료인간의 안전 분위기'의 높은 지각과 높은 '병원에의 간호사 참여'와 '인적 자원의 적절성'은 낮은 '불안감'과 '행정자들의 반응'과 관련이 있었다. 투약오류보고장애를 위한 전략과 안전 분위기와 업무환경과 같은 조직의 특성의 진보가 적용되어야 한다.

• 디지털융복합연구
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• 제20권2호
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• pp.573-583
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• 2022

본 연구는 블랜디드러닝 성인간호학 교육에 노트필기 전략을 적용하여 그 효과를 분석하고자 시도되었다. 33명의 간호대학생을 대상으로 단일 집단 사전·사후 설계로 하여, 2021년 9월 17일부터 10월 15까지 자료 수집 후 SPSS/WIN 26.0으로 분석하였다. 주요 결과로 학습동기는 수업 전 3.27에서 수업 후 3.40점으로 상승하였으나 유의한 차이를 보이지 않았고(t=-1.501, p=.143), 수업 참여도는 수업 전 2.95점에서 수업 후 3.27점으로 유의하게 상승하였다(t=-2.669, p=.012). 수업 전 학습동기는 수업 전 참여도(r=.838, p<.001), 수업 후 학습동기(r=.545, p=.001), 수업 후 참여도(r=.462, p=.007)와 각각 유의한 양의 상관관계를 보였다. 성별(Wilks'𝛌=.866), 수업 흥미(Wilks'𝛌=.632)와 수업 만족도(Wilks'𝛌=.822)에 따른 학습동기 및 수업 참여도는 모두 유의수준 .05보다 크므로 유의한 차이는 없었다. 이러한 결과를 토대로 블랜디드러닝 성인간호학 교육에 노트필기 전략을 적용한 것은 수업 참여도를 향상시키는데 효과가 있었으며, 추후 학업 성취에 따른 맞춤형 노트필기 전략을 적용하여 효과를 검증할 필요가 있다.

• Nuclear Engineering and Technology
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• 제42권2호
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• pp.163-174
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• 2010

As pointed out in the OECD BEMUSE Program, when a high computation time is taken to obtain the relevant output values of a complex physical model (or code), the number of statistical samples that must be evaluated through it is a critical factor for the sampling-based uncertainty analysis. Two alternative methods have been utilized to avoid the problem associated with the size of these statistical samples: one is based on Wilks' formula, which is based on simple random sampling, and the other is based on the conventional nonlinear regression approach. While both approaches provide a useful means for drawing conclusions on the resultant uncertainty with a limited number of code runs, there are also some unique corresponding limitations. For example, a conclusion based on the Wilks' formula can be highly affected by the sampled values themselves, while the conventional regression approach requires an a priori estimate on the functional forms of a regression model. The main objective of this paper is to assess the feasibility of the ACE-RSM approach as a complementary method to the Wilks' formula and the conventional regression-based uncertainty analysis. This feasibility was assessed through a practical application of the ACE-RSM approach to the LOFT L2-5 LBLOCA PCT uncertainty analysis, which was implemented as a part of the OECD BEMUSE Phase III program.

• 대한수학회지
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• 제47권2호
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• pp.385-407
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• 2010

To study the relationship between the levels of chemical pollutants and the number of daily total hospital admissions for respiratory diseases and to find the effect of temperature/relative humidity on the admission number, Wong et al. [17] introduced the varying-coefficient single-index model (VCSIM). As pointed out, it is a popular multivariate nonparametric fitting technique. However, the tests of the model have not been very well developed. In this paper, based on the estimators obtained by the local linear technique, the average method and the one-step back-fitting technique in the VCSIM, the generalized likelihood ratio (GLR) tests for varying-coefficient parts on the VCSIM are established. Under the null hypotheses the new proposed GLR tests follow the $\chi^2$-distribution asymptotically with scale constant and degree of freedom independent of the nuisance parameters, known as Wilks phenomenon. Simulations are conducted to evaluate the test procedure empirically. A real example is used to illustrate the performance of the testing approach.

• 응용통계연구
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• 제7권2호
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• pp.213-224
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• 1994

두개의 공분산 행렬의 동질성을 검정하는데 있어서, influence curve 방법을 이용하여 outlier를 찾는데 유용한 진단법을 제시한다. 이러한 진단법은 두개 이상의 공분산 행렬의 경우에 쉽게 일반화된다. 경험적 분포함수에 입각한 진단법의 sample version을 고려하며, 이것은 Wilks가 제안한 한개의 outlier를 찾는데 필요한 통계량과 두개의 모집단의 경우로 일반화된 Wilks 통계량을 포함한다.