• 한국데이터정보과학회:학술대회논문집
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• 한국데이터정보과학회 2005년도 춘계학술대회
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• pp.69-82
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• 2005

Factorial experiments are studied in this paper. The Designs, thus, have factorial balance with respect to estimable main effects and interactions. John and Lewis (1983) considered generalized cyclic row-column designs for factorial experiments. A simple method of constructing confounded designs using the classical method of confounding for block designs is described in this paper.

• Journal of Preventive Medicine and Public Health
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• 제15권1호
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• pp.179-186
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• 1982

The methods controlling the confounding factors were discussed using the data of secondary infertility with induced abortion. Mantel-Haenszel method and logistic model were applied in the analysis to find out which factors were confounding and/or effect modification variables. In the logistic analysis, the main effect of induced abortion, spontaneous abortion, age and interaction effect between induced abortion and spontaneous abortion were chosen as independent variables being regressed into logistic functions. Spontaneons abortion was interpreted as a potential confounder and at the same time potential effect modifier and age was interpreted as potential confounder. Spontaneous abortion was shown to be more important influencing factor than age to the secondary infertility. In the course of logistic analysis, the problem of parameter estimation and hypothesis testing, assessing the fitness of a model, and selection of the best model were briefly explained. For the program of logistic model, FUNCAT Procedure of SAS package was chosen.

• Communications for Statistical Applications and Methods
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• 제15권4호
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• pp.497-507
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• 2008

동일 환경에서 할 수 있는 실험의 크기가 2인 경우 $2^n$요인실험과 그 일부실시법을 설계하려면 교락법을 반복적으로 사용해야한다. $2^n$요인실험 또는 그 일부실시법의 교락법들을 적절히 조합하면 모든 주효과와 2인자 교호작용효과 전부 또는 일부를 검출할 수 있는 실험을 설계할 수 있다. 이런 실험을 설계하기 위해 정의대비를 이용했고 설계된 실험의 처리조합을 제시하였다.

• 보건교육건강증진학회지
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• 제21권3호
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• pp.1-17
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• 2004

The purpose of this study is to evaluate the roles of expected self-control and expected self-control results in explaining adolescents' Internet addiction. In the study model, expectations of self-control and self-control results directly determine Internet addiction and Internet use time meditates the impacts of expectations of self-control and self-control results on Internet addiction. The study subjects are 1,080 middle and high school students in Busan. Stratified cluster sampling is applied by school type and school year. The response rate is 96%(l,037cases). This study develops the scales of expected self-control and expected self-control results. The scales of Internet addiction are devised by using the concept of functional dependency such as salience, withdrawal symptoms, mood modification, tolerance, relapse, and conflict. For verifying the study model, path analysis and multiple regression models are applied for identifying path significants and evaluating confounding effects of control variables, respectively. Moreover, multi partial F-test is performed for selecting the best regression model. Expected self-control is a significant determinant of Internet addiction and Internet use time that also significantly explains Internet addiction. The total effect of expected self-control towards Internet addiction is -.95. The total effect is comprised with the direct effect (-.71) and the indirect effect(-.24). In this result, the direct effect refers a curative effect since expected self-control directly reduces the level of Internet addiction, and the indirect effect refers a preventive effect because self-control can reduce time of Internet use that is a direct determinant of Internet addiction. In the test of the confounding effects of control variables, there are no confounding effects in the models of multiple regression. It implies a robustness of the study model as regards control variables. In conclusion, improving adolescents' expected self-control can control Internet addiction level. This finding implies that a health promotion program for improving expected self-control can be a cost effective method compared to other approaches.

• 생물정신의학
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• 제27권2호
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• pp.101-111
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• 2020

Objectives The aim of this study is to investigate the association between secondhand smoke (SHS) exposure and depressive symptoms among Korean adults. This study also explored the mediating role of self-rated health (SRH) and perceived usual stress (PUS) in the association between depressive symptoms, suicidal ideation and SHS exposure. Methods Data from the Korea National Health and Nutrition Examination Surveys (KNHANES) in 2014 and 2016 was analyzed for 10539 participants aged 19 years or older. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated in the logistic regression analysis with adjustment for the potential confounding factors. We also adopted the mediation analysis method by Hayes and Preacher. Results After adjusting for the potential confounding factors, SHS at home and at public places were associated with depressive symptoms and suicidal ideation among non-smokers. After adjusting for the potential confounding factors, SHS at home and at public places was associated with depressive symptoms and suicidal ideation among non-smokers. Meanwhile SHS at workplaces was associated with depressive symptoms among former smokers and with suicidal ideation among current smokers. There was an additive effect of SHS on depressive symptoms only among non-smokers. SRH mediated the association between SHS and depressive symptoms and suicidal ideation among non-smokers. We did not observe any significant mediating effect of SRH nor PUS on the association between SHS and depressive symptoms among former and current smokers. Conclusions SHS may be associated with depressive symptoms and suicidal ideation in Korean adults. Our study elucidated how SHS interacted with depressive symptoms among non-smokers through the mediation by SRH.

• 한국통계학회:학술대회논문집
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• 한국통계학회 2004년도 학술발표논문집
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• pp.313-317
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• 2004

Confounded row-column designs for factorial experiments are studied in this paper. The Designs, thus, have factorial balance with respect to estimable main effects and interactions. John and Lewis (1983) considered generalized cycle row=column designs for factorial experiments. A simple method of constructing confounded designs using the classical method of confounding for block designs is described in this paper

• Communications for Statistical Applications and Methods
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• 제7권1호
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• pp.119-128
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• 2000

This paper proposes a method for detecting interactions in a two-way layout with one observation per cell. The identification of interactions in the model is not clear for they are confounding with error terms. The $L_1$-Estimation is robust with respect to a y-direction outlier in linear model so we are able to estimate main effects without affection of interactions, If an observation is classified as an outlier we conclude it contains an interaction. An empirical study compared with a classical method is performed.

• 응용통계연구
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• 제36권1호
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• pp.63-83
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• 2023

기존의 많은 연구에서 도시공원을 비롯한 녹지와 유아 행복감 간에 유의미한 상관관계를 도출했다. 또한 이를 통해 간접적으로 도시공원의 면적/근접성이 유아기의 행복감 증진에 효과가 있을 것이라 유추하였다. 하지만 관찰된 자료를 통한 인과효과 추정은 교란 변수의 적절한 조정을 필요로하고, 이런 관점에서 도시공원의 면적과 유아 행복감의 인과관계는 명확히 밝혀지지 않았다고 할 수 있다. 본 연구에서는 한국아동패널 자료를 이용하여 도시공원의 면적이 유아 행복감에 미치는 영향에 대한 인과효과를 추정하였다. 교란 변수를 조정하기 위한 방법으로 회귀 모형을 이용한 조정(regression adjustment), 가중치 기법(weighting), 그리고 매칭(matching) 등을 이용하였고, 각 방법들의 중요 개념을 분석 결과에 앞서 기술하였다. 교란 변수의 선택에 있어서 유향 비순환 그래프(directed acyclic graph)를 사용하였다. 분석 결과, 기존의 상관관계를 이용한 결론과는 다르게 도시공원의 면적과 유아 행복감 간에는 유의미한 인과효과가 존재하지 않았다.

• 보건교육건강증진학회지
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• 제21권1호
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• pp.1-23
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• 2004

The purpose of this study is to examine the effects of job-related characteristics on alcohol consumption among female workers. The Data was collected from a sample of 1,000 female workers by a stratified proportional quota sampling method derived from those who were working in Seoul. Drinking behavior pattern includes total amount of pure alcohol consumed during the last month (AC) measured by graduated quantity-frequency. Job-related characteristics (JRC) were measured by job-related stress, work characteristics, and organizational structure including length of working hours, number of times dining out together with workers per year, number of staff to supervise, employment status, occupational category, and proportion of female workers to male counterpart. Confounding variables include sociodemogrphic and socio-cultural attitudes toward alcohol expectancy, subjective norm of drinking, and gender-role attitude. Hierarchical multiple regression models show that the variability of AC was accounted for by some JRC including number of times dining together and employment status, with confounding variables held constant. However, the relationship between AC and JRC varied across occupational categories. Some implications were discussed in terms of health policy for female workers and further study for female drinking behavior.

• 응용통계연구
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• 제25권1호
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• pp.163-181
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• 2012

비정규직 재직자 직업능력개발에 대한 훈련 효과 추정을 위해 이 연구에서는 통계청의 경활 자료와 비모수적 매칭 방법을 사용하였다. 추정결과 재직자 직업능력개발 훈련은 정규직 자에게는 정규직 유지가능성을 높이고 비정규직 자에게는 임금보다는 정규직 전환확률을 높이는 것으로 나타났다. 또한 미관찰 요인에 의한 추정결과의 강건성을 알아보는 민감도 분석에서는 미관찰 요인은 추정결과에 크게 영향을 미치지 않는 것으로 나타났다.