• Nuclear Engineering and Technology
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• v.46 no.4
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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.

• Journal of Sensor Science and Technology
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• v.23 no.5
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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).

• Journal of the East Asian Society of Dietary Life
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• v.15 no.4
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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.

• Journal of Sensor Science and Technology
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• v.24 no.4
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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.

• Journal of the Korean Society of Food Culture
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• v.20 no.6
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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.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.2
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• pp.979-988
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• 2014

Purpose: The purpose of this study was to examine the relationship between nurse's perception of organizational characteristics including safety climate and work environment and barrier to medication error reporting. Methods: We surveyed 334 nurses from 7 hospitals. An assessment survey was consisted of modified safety climate scale, practice environment scale and barrier to medication error reporting. The data were collected from September 2012. Descriptive statistics, Pearson correlation coefficient, canonical correlation were used. Results: Organizational characteristics were related to barrier to medication error reporting with three significant canonical variables. The first canonical correlation coefficient was .50(Wilks' ${\lambda}$=0.61, df=32, p<.001), that of the second was .35(Wilks' ${\lambda}$=0.81, df=21, p<.001) and that of the third was .22(Wilks' ${\lambda}$=0.93, df=12, p=.018). The first variate indicated higher perception of safety climate variables and work environment variables were related lower barrier to medication error reporting variables except fear for error reporting. The second variate showed higher perception of 'safety climate between healthcare provider' and higher 'nurse participation in hospital affairs' and 'staffing and resource adequacy' were related to lower 'fear' and 'administrative response' in barrier to medication error reporting variables. Conclusion: Strategies for barrier to medication error reporting and improvement of organizational characteristics including safety climate and work environment should be implemented.

• Journal of Digital Convergence
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• v.20 no.2
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• pp.573-583
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• 2022

This study was attempted to analyze the effect of a note-taking strategy applied to blended learning adult nursing education. Data were collected from September 17 to October 15, 2021, and analyzed using the SPSS/WIN 26.0 program with a single group pre/post design targeting 33 nursing students. As a main result, learning motivation rose from 3.27 before class to 3.40 after class, but there was no significant difference(t=-1.501, p=.143), and class participation significantly increased from 2.95 before class to 3.27 after class(t=-2.669, p=.012). Motivation for learning before class was pre-class participation(r=.838, p<.001), learning motivation after class(r=.545, p=.001), and class participation after class(r=.462, p=.007) and each showed a significant positive correlation. Learning motivation and class participation according to gender(Wilks'𝛌=.866), class interest(Wilks'𝛌=.632), and class satisfaction(Wilks'𝛌=.822) were all higher than the significance level of .05, so they were no significant difference. Based on these results, applying a note-taking strategy to blended learning adult nursing education was effective in improving class participation. In a future study, it is necessary to verify the effectiveness by applying a note-taking strategy customized according to academic achievement.

• Nuclear Engineering and Technology
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• v.42 no.2
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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.

• Journal of the Korean Mathematical Society
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• v.47 no.2
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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.

• The Korean Journal of Applied Statistics
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• v.7 no.2
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• pp.213-224
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• 1994

A diagnostic method useful for detecting outliers in testing the equality of two covariance metrics is developed using the influence curve approach. This method is easily generalized to more than two covariance matrices. A sample version for the influence measure of detecting outliers is considered based on the empirical distribution functions. The sample version includes as its component terms the well-known test statistic for detecting one outlier at a time introduced by Wilks and its generalization to the two-group case.