• Journal of the Korean Statistical Society
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• 제18권2호
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• pp.85-96
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• 1989

This paper is concerned with the strong consistency of the least squares estimators for the nonlinear regression models. A simple and practical sufficient condition for the strong consistency of the least squares estimators is given. It is also discussed that the extension of the strong consistency to a wide class of regression functions can be established by imposing some condition on the input values. Some examples are given to illustrate the application of main result.

• Journal of the Korean Statistical Society
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• 제8권1호
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• pp.23-36
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• 1979

In the multiple linear regression model a class of weighted least absolute error estimaters, which minimize the sum of weighted absolute residuals, is proposed. It is shown that the weighted least absolute error estimators with Wilcoxon scores are equivalent to the Koul's Wilcoxon type estimator. Therefore, the asymptotic efficiency of the proposed estimator with Wilcoxon scores relative to the least squares estimator is the same as the Pitman efficiency of the Wilcoxon test relative to the Student's t-test. To find the estimates the iterative weighted least squares method suggested by Schlossmacher is applicable.

• Journal of the Korean Statistical Society
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• 제28권2호
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• pp.195-210
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• 1999

We consider a large class of exponential regression models with censored data and propose two modified Fisher scoring methods with corresponding algorithms. These proposed methods improve the Newton-Raphson method in estimating the model parameters. The simulated and real examples are illustrated in aspect of convergence.

• Communications for Statistical Applications and Methods
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• 제7권3호
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• pp.643-654
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• 2000

In this paper, we review some class of t-norms on which fuzzy arithmetic operations preserve the shapes of fuzzy numbers and the Hausdorff-distance between fuzzy numbers as the measure of distance between fuzzy numbers. And we suggest the least Hausdorff-distance square method for fuzzy linear regression model using shape preserving fuzzy arithmetic operations.

• 품질경영학회지
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• 제20권2호
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• pp.67-75
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• 1992

In this paper we propose a class of tests for the parallelism of two regression lines based on linear placement statistics. The results of a small-sample Monte Carlo study show that the proposed tests are reasonably good in level control and powers.

• 한국통계학회:학술대회논문집
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• 한국통계학회 2005년도 춘계 학술발표회 논문집
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• pp.95-100
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• 2005

In this paper a class of multifactor designs for estimating the slope of second order response surface regression models with correlated errors is considered. General conditions for second order slope rotatability over all directions and also with respect to the maximum directional variance in case of k=2 have been derived assuming errors have a general correlated error structure. And we consider the measures for evaluating slope rotatability with correlated errors similar to in case of uncorrelated error structures.

• Restorative Dentistry and Endodontics
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• 제35권2호
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• pp.116-124
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• 2010

본 연구에서는 복합 레진을 이용한 2급/5급 와동의 직접수복에 있어서 치과의사의 성별에 따른 술식의 차이를 비교하였다. 2008년 대한치과의사협회에 등록된 치과의사 12,193명을 대상으로 이 메일을 통한 설문조사를 실시하였다. 이 메일 수신이 확인된 2,632명 중 840명이 응답하였으며 응답자의 남녀 비율은(남 78.9%, 여 21.1%) 전체 치과의사의 남녀 비율과 유의한 차이를 보이지 않았다(p > 0.05). Chi-square test 와 multiple logistic regression analysis 를 이용하여 남녀간 술식의 차 이를 검증하였다. 2급 와동 수복에서 여자치과의사는 4회 이상의 적층 분할 수복을 하는 경향이 남자치과의사에 비해 1.87배 높았으며, 술식 당 30분 이상 소요하는 경향은 2.72배 높았다(p < 0.05). 5급 와동 수복에서 여자치과의사는 베이스를 사용하는 경향이 1.83배 높았으며, 술식 당 20분 이상 소요하는 경향은 1.63배 높았다(p < 0.05). 본 설문조사에 따르면 남녀 성별에 따라 복합 레진 수복 술식의 차이가 존재하는 것으로 나타났다.

• 한국융합학회논문지
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• 제12권11호
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• pp.257-263
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• 2021

본 연구는 온라인 수업만족도에 영향을 미치는 요인을 분석하여 비대면 수업을 보다 효과적으로 운영하기 위한 기초자료로 활용하고자 하였다. 설문 조사는 전북과 충북에 소재한 치기공과 재학생의 208부 설문지를 분석하였다. SPSS 프로그램을 이용하여 신뢰도 분석, 기술적 통계, 평균분석(t-test, one-way ANOVA), Pearson의 상관분석, 단계적 다중회귀분석을 시행하였다. 분석결과 연구대상자의 시간적 기대 효익은 3.87, 학습효과 기대 효익은 3.30, 기술 친숙도는 3.40, 수업만족도는 3.21로 나타났다. 수업만족도에 가장 큰 영향을 미치는 요인은 기술적 친숙도이었다. 온라인 수업만족도를 높이기 위하여 수업에 활용되는 학습 도구의 활용능력과 온라인 수업 시스템에 대한 기술적 친숙도를 향상시키기 위한 학습환경을 구축해야 할 것이다.

• 대한치과교정학회지
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• 제43권4호
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• pp.193-200
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• 2013

Objective: To evaluate the psychosocial impact of malocclusion, determine its relationship with the severity of malocclusion, and assess the influence of gender and social class on this relationship in adolescents. Methods: A random sample of 627 Spanish adolescents aged 12 - 15 years underwent intraoral examinations by 3 calibrated examiners (intraexaminer and interexaminer kappa > 0.85) at their schools. Psychosocial impact was measured through a self-rated Psychosocial Impact of Dental Aesthetics Questionnaire (PIDAQ). The severity of malocclusion was measured by the Index of Orthodontic Treatment Need (IOTN). Gender and social class were also recorded. Results: The total PIDAQ score and those of its 4 subscales, social impact, psychological impact, aesthetic concern, and dental self-confidence, presented significant differences ($p{\leq}0.05$ by analysis of variance) and linear relationships with the IOTN grades ($p{\leq}0.05$ by linear regression). Stepwise linear regression models showed that the IOTN dental health component was a predictive variable of the total and subscale PIDAQ scores. Neither gender nor social class was an independent predictive variable of this relationship, except the linear model for psychological impact, where gender was a predictive variable. The occlusal conditions responsible for higher PIDAQ scores were increased overjet, impeded eruption, tooth displacement, and increased overbite. Conclusions: Malocclusion has a psychological impact in adolescents and this impact increases with the severity of malocclusion. Social class may not influence this association, but the psychological impact seems to be greater among girls.

• 아동학회지
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• 제38권2호
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• pp.165-176
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• 2017

Objective: Delinquent peers are important predictors of adolescent delinquent behavior. Few studies have classified individuals into groups based on patterns of delinquent behavior among youth and their peers. This study identified latent groups based on adolescent-peer delinquency and examined psychosocial characteristics of each latent group. Methods: First, the study employed latent class analysis based on a nationally representative data of South Korean middle school students (N = 2,277). Both adolescent and peer delinquent behaviors comprised 13 items in the questionnaire that was self-reported by adolescents. Second, the study used multivariate regression models to analyze psychosocial symptoms of latent groups and conducted Wald tests to compare differences among latent groups. Results: Patterns of adolescent-peer delinquency were classified into six latent groups. "Mutual total delinquent group (1.2%)" showed high rates in most delinquent experiences. "Mutual status delinquent group (5.7%)" mainly experienced status delinquency, "Mutual violence delinquent group (5.3%)" showed high rates of violent delinquency. "Peer-only total high delinquent group (3.8%)" reported friends to have engaged in all types of delinquency and "Peer-only total medium delinquent group (11.8%)" reported peer involvement in multiple status and few violent delinquency. Finally, "low risk group (72.2%)" reported low rates of delinquency for themselves and their friends. Regression analysis showed that every "mutual" delinquent group presented significantly worse psychosocial problems than the "low risk group." Conclusion: Using person centered latent class analysis, this study classified six latent classes while considering both delinquent agents and various types of delinquency and investigated specific groups with greater risk of psychosocial problems.