• Nuclear Engineering and Technology
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• 제46권5호
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• pp.719-724
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• 2014

During the development process of a thermal-hydraulic system code, a non-regression test (NRT) must be performed repeatedly in order to prevent software regression. The NRT process, however, is time-consuming and labor-intensive. Thus, automation of this process is an ideal solution. In this study, we have developed a program to support an efficient NRT for the SPACE code and demonstrated its usability. This results in a high degree of efficiency for code development. The program was developed using the Visual Basic for Applications and designed so that it can be easily customized for the NRT of other computer codes.

• 한국물환경학회지
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• 제23권3호
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• pp.385-390
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• 2007

Reliable flow measurement for dry season is very important to set up the in-stream flow exactly and total maximum daily load control program in the basin. Especially, in the points which tidal current effects are dominant because reliability of the low measurement decrease. The reliable measuring methods are needed. In this study, we analysis the water surface elevation difference of water surface elevation. Quantity relationship to consider tidal currents in these regions. It is known that tidal current effects from Nakdong river barrage are dominant in Samrangjin measuring station. We developed multiple regression equation with water surface elevation, quantity, and difference of water surface elevation and compared these results water measured rating curve. All of these regression equation including linear regression equation and log regression equation fits better measured data them existing water surface elevation quantity line and Among three equations, the log regression equation is best to represent the measured the rating curve in Samrangjin point. The log regression equation is useful method to obtain the quantity in the regions which tidal currents are dominant.

• Genomics & Informatics
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• 제14권4호
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• pp.149-159
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• 2016

With the success of the genome-wide association studies (GWASs), many candidate loci for complex human diseases have been reported in the GWAS catalog. Recently, many disease prediction models based on penalized regression or statistical learning methods were proposed using candidate causal variants from significant single-nucleotide polymorphisms of GWASs. However, there have been only a few systematic studies comparing existing methods. In this study, we first constructed risk prediction models, such as stepwise linear regression (SLR), least absolute shrinkage and selection operator (LASSO), and Elastic-Net (EN), using a GWAS chip and GWAS catalog. We then compared the prediction accuracy by calculating the mean square error (MSE) value on data from the Korea Association Resource (KARE) with body mass index. Our results show that SLR provides a smaller MSE value than the other methods, while the numbers of selected variables in each model were similar.

• 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.

• 융합경영연구
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• 제10권5호
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• pp.15-24
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• 2022

Purpose: The purpose of this study is to find a way to improve and overcome the psychological treatment limited to the negative factors dealt with in psychology from a positive psychological point of view. To this end, this study aims to verify whether a positive psychotherapy program can improve happiness, resilience, and post-traumatic growth along with improvement of psychological symptoms such as depression. Research design, data and methodology: To this end, in this study, mean difference analysis was conducted using t-test on 10 participants in the 16th PPT program and 14 in the control group. Also, after setting the main variables, we tried to confirm the effectiveness through simple regression analysis and multiple regression analysis of the causal relationship model. Results: As a result of the independent sample t-test and the paired sample t-test, it was confirmed that the group participating in the PPT program had higher flourish, happiness, resilience, post-traumatic growth, and lower depression. In addition, as a result of regression analysis, it was confirmed that post-traumatic growth had a positive effect, and that depression was a life-threatening factor. Conclusions: Since the PPT program has a positive effect on the participants with relatively negative psychological symptoms, it is necessary to expand it. In addition, it is necessary to introduce various preventive programs such as PPT as well as traditional psychological treatment for negative symptoms such as depression.

• 보건의료산업학회지
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• 제10권4호
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• pp.87-95
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• 2016

Objectives : The aim of this study was to investigate the degree of awareness of the national cancer screening program by the Korean public and define its relationship with cancer screening intention. Methods : The study collected data by conducting an online survey from April 19 to 24, 2016, and received a total 354 responses. Additionally, we performed frequency analysis, chi-square test, and logistic regression analysis. Results : Based on the results for the degree of awareness for the national cancer screening program, 151 (42.7%) people were aware of the program, while 203 (57.3%) were not aware the program. From the chi-square test and logistic regression analysis, marital status and awareness of the national cancer screening program were found to have a statistically significant influence on screening intention. Conclusions : An increase in the screening rate should be established with a systematic promotion plan for the national cancer screening program.

• 한국도로학회논문집
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• 제19권5호
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• pp.49-58
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• 2017

PURPOSES : The objective of this study is to develop a simple regression model in designing the asphalt concrete (AC) overlay thickness using the Mechanistic-empirical pavement design guide (MEPDG) program. METHODS : To establish the AC overlay design equation, multiple regression analyses were performed based on the synthetic database for AC thickness design, which was generated using the MEPDG program. The climate in Seoul city, a modified Hirsh model for determining dynamic modulus of asphalt material, and a new damaged master curve approach were used in this study. Meanwhile, the proposed rutting model developed in Seoul city was then used to calibrate the rutting model in the MEPDG program. The AC overlay design equation is a function of the total AC thickness, the ratio of AC overlay thickness and existing AC thickness, the ratio of existing AC modulus and AC overlay modulus, the subgrade condition, and the annual average daily truck traffic (AADTT). RESULTS : The regression model was verified by comparing the predicted AC thickness, the AADTT from the model and the MEPDG. The regression model shows a correlation coefficient of 0.98 in determining the AC thickness and 0.97 in determining AADTT. In addition, the data in Seoul city was used to validate the regression model. The result shows that correlation coefficient between the predicted and measured AADTT is 0.64. This indicates that the current model is more accuracy than the previous study which showed a correlation coefficient of 0.427. CONCLUSIONS:The high correlation coefficient values indicate that the regression equations can predict the AC thickness accurately.

• 한국도로학회논문집
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• 제10권3호
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• pp.129-138
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• 2008

기존 콘크리트 포장의 단면 설계 시 발생하는 문제점을 해결하기 위해 유한 요소법(FEM)을 이용하여 것이 하나의 방법론으로 부각되었으며 현재 한국형 포장 설계법 개발 연구에서도 적용 중에 있다. 본 연구에서는 ABAQUS와 포트란 해석 프로그램을 이용하여 콘크리트 포장의 한계 응력을 계산하였고, 그 결과를 뉴럴 네트워크와 선형 회귀식을 이용하여 비교 분석하였다. 입력 변수가 많지만 다양한 해석을 하지 못하는 경우(입력변수 6개에 대해 81 경우 수 해석)에 대해 구조해석 결과를 뉴럴 네트워크(이하 NN: Neural Networks)와 선형 회귀식으로 비교한 결과, 구조해석 결과와 다소 차이가 있음을 확인하였다. 반면 입력 변수를 줄이되 다양한 경우에 해석한 경우(입력 변수 3개에 대해 343 경우의 수)의 분석 결과, NN과 선형 회귀식이 구조해석 결과와 매우 유사한 결과가 나타나는 것을 알 수 있었다. 하지만 그래프의 (0,0), (1,1) 부분에서 NN이 선형 회귀식에 비해 더 정확한 것을 확인하였다. 이와 같은 연구 결과를 통해서 한국형 포장 설계법의 핵심인 응력 계산 모듈을 선형 회귀식보다 좀 더 정확한 NN으로 해석하는 것을 제안하였다.

• 전기학회논문지
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• 제56권1호
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• pp.28-34
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• 2007

Recently, with the rapid growth of industry, environmental condition became worse. In addition to outdoor insulators in seashore are polluted due to salty wind. Also this pollution causes the flashover and failure of electric equipments. Especially the salt contaminant is one of the most representative pollutants, and known as the main source of the accident by contamination. As well known, the pollution has a close relation with meteorological factors such as wind velocity, wind direction, temperature, relative humidity, precipitation and so on. In this paper we have statistically analyzed the correlation between the pollution and the meteorological factors. The multiple regression analysis was used for the statistical analysis; daily measured equivalent salt deposit density(dependent variable) and the weather condition data(independent variable) were used. Also we have developed an expert program to predict the pollution deposit. A new prediction system using this program called SPPP(salt pollution prediction program) has been used to model accurately the relationship between ESDD with the meteorological factors.

• 한국치위생학회지
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• 제13권1호
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• pp.158-165
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• 2013

Objectives : The purpose of this study was to obtain the community residents' support and approval on the water fluoridation program in Mokpo, Korea. Methods : Questionnaires of this were 1085 adults, over the age of 20, who resided in the Mokpo city for over the 1year. In order to analyze the factors that were related to the approval on administering water fluoridation program, the data analyzed using a chi-squared test and a multiple logistic regression analysis. Results : Respondents approving the implementation of water fluoridation were 50.5%. The general factors of approval were age, education, Monthly household income. The knowledge factors of approval were experience of hearing of this program, the knowledge of the purpose of this program, the knowledge of the some regions in South Korea had been implement water fluoridation. The results of multiple logistic regression analysis were the awareness of oral health and the knowledge level of water fluoridation were related with this program approval. Conclusions : In order to enhance the rate of approval on administrating the water fluoridation, it is necessary to publicize the purpose, effect, and stability of this program, through a diverse mass media and reinforce the health education program to oral health management.