• 한국병원경영학회지
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• 제20권1호
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• pp.53-64
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• 2015

Our objective was to evaluate differences in linear regression versus multilevel(cross-level interaction model) modeling for affecting factors lumbar discectomy. The data were used in 2011 patients with HIRA sample data. Total number of analysis is 3,641 patients and 248 hospitals. The results of research model showed that the type and location of the hospital-level factors were significant. However, all factors of patient-level were similar in the two models. Therefore, it requires the selection of an appropriate model for a more accurate analysis of the influencing factors in the daily medical charge.

• Journal of Periodontal and Implant Science
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• 제45권1호
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• pp.2-7
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• 2015

A fundamental problem in analyzing complex multilevel-structured periodontal data is the violation of independency among the observations, which is an assumption in traditional statistical models (e.g., analysis of variance and ordinary least squares regression). In many cases, aggregation (i.e., mean or sum scores) has been employed to overcome this problem. However, the aggregation approach still exhibits certain limitations, such as a loss of power and detailed information, no cross-level relationship analysis, and the potential for creating an ecological fallacy. In order to handle multilevel-structured data appropriately, mixed effects models have been introduced and employed in dental research using periodontal data. The use of mixed effects models might account for the potential bias due to the violation of the independency assumption as well as provide accurate estimates.

• 부동산연구
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• 제27권3호
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• pp.51-70
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• 2017

이 연구는 가로망 폭을 반영하여 가로망 중심성을 측정하고 그 효과를 토지가격을 통해 규명한다. 그동안 도시공간구조를 분석한 도시경제와 정책에 대한 연구는 단핵도시구조에서 다핵도시구조로 발전하여 왔다. 그러나 이러한 시각은 여전히 도시현상을 설명하는 데 한계가 있으므로 미시공간수준의 가로망 분석이 새로운 연구영역으로 자리잡고 있다. 특히, 최근에 가로망 중심성을 다양한 방법으로 측정하고 도시현상에 대한 효과를 경험적으로 분석하는 연구가 많아지고 있다. 이 연구는 기존의 시각을 확장하기 위해 가로망 폭을 반영한 중심성을 측정한 후 주거용과 비주거용 토지가격에 대한 효과를 분석하였다. 이 연구의 다층회귀분석모형 결과는 대체로 주거용 토지의 경우 폭이 넓은 가로망에 도달하는 경유 빈도가 많고 이러한 가로망에 가까이 있으면 가격이 높은 것으로 나타났다. 비주거용 토지는 넓은 가로망에 도달하는 경유 빈도가 높고 가시성이 높은 가로망에 가까이 있으면 가격 수준이 높았다. 이러한 연구 결과는 가로망 폭을 고려한 보다 현실적인 가로망 중심성이 토지 시장에 미치는 효과를 경험적으로 검증한 것이다. 이를 통해 가로망 중심성이 향후 토지가격에 미치는 영향을 규명하고 장기적으로 토지시장의 변화를 예측할 수 있는 기초 자료가 될 것이다.

• 보건교육건강증진학회지
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• 제29권2호
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• pp.83-91
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• 2012

Objectives: This study is to examine that drinking problems among university students were accounted for not only by student's individual characteristics but alcohol policy and environmental characteristics of the university in which students were enrolled. Method: Secondary data analysis was employed in which variables under study were derived from a raw data of a nationwide representative sample in 2009. Raw data under analysis included 3,665 students from 63 universities across Korea. Organizational and environmental characteristics of the university were collected from university administrators while individual characteristics and drinking behavior from the students in using self-administrated questionnaire. Multilevel regression analyses were employed to describe alcohol policy effects on students's drinking problems measured by AUDIT by using HLM7.0. Results: ICCs indicate that variation in drinking problem depends on alcohol policy of university. Multilevel regression models identified statistically significant factors in explaining variance of drinking problems. Group means on drinking problem are affected by indicators representing alcohol policy with level of drinking problem of student being decreased in accordance to level of availability of alcohol on campus. Conclusions: It is concluded that drinking problems among university students were associated with both individual characteristics and alcohol policy of the university they enrolled. This study supports policy belief that interventions at environmental as well as individual level are required to prevent drinking problem among university students.

• 지적과 국토정보
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• 제48권2호
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• pp.197-211
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• 2018

본 연구에서는 건강에 대한 공간적 연구에서 통상적으로 사용되는 센서스에 기반한 지역 박탈지수의 대안으로 지역 주택가격이 사용될 수 있는지 평가하였다. 평가를 위해 개인을 1수준으로, 수도권의 보건소 구역을 2수준으로 하는 다수준 로지스틱 모델이 추정되었다. 다수준 모델에는 개인의 점심식사후 칫솔질과 치간실 사용을 설명하기 위한 개인수준의 변수들과 보건소 구역을 대표하는 사회적 박탈지수 및 지역주택가격 수준이 포함되었다. 추정된 모델들의 설명력은 Akaike Information Criterion (AIC)와 Bayesian Information Criterion (BIC)를 이용하여 평가되었다. 모델의 추정결과는 사회적 박탈지수 및 지역 주택가격이 모두 개인의 치아관리 행동을 설명하는 데 기여하나 지역 주택가격을 사용한 모델의 AIC 및 BIC가 통상적인 센서스 기반 지역 박탈지수를 사용한 경우 보다 낮은 것을 보여 주었다. 본 연구결과는 센서스에 기반한 박탈지수를 생성하는 데 사용된 센서스 변수가 시점의 차이 등의 이유로 적절하지 않을 경우 지역 주택가격이 지역의 사회경제적 수준을 대표하기 위해 대안적으로 사용될 수 있음을 보여준다.

• 보건행정학회지
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• 제25권1호
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• pp.31-39
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• 2015

Background: The purpose of this study is comparison of the results between regression and multi-level analysis to find out factors influencing outcome indicators (in-hospital death, length of stay, and medical charges) of stroke patients. Methods: By using patient sample data of Health Insurance Review & Assessment Service, patients admitted with stroke were selected as survey target and 15,864 patients and 762 hospitals were surveyed. Results: For the results of existing regression analysis and multi-level analysis, models were assessed through model suitability index value and as a result, the value of results of multi-level analysis decreased compared to the results of regression, showing it is a better model. Conclusion: Factors influencing in-hospital death of stroke patients were analyzed and as a result, intra-class correlation (ICC) was 13.6%. In factors influencing length of stay, ICC was 11.4%, and medical charges, ICC was 17.7%. It was found that factors influencing the outcome indicators of stroke patients may vary in every hospital. This study could carry out more accurate analysis than existing research findings through analysis of reflecting structure at patient level and hospital level factors and analysis on random effect.

• Journal of Preventive Medicine and Public Health
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• 제53권3호
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• pp.189-197
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• 2020

Objectives: Our aim was to answer the following questions: (1) Can mental health variance be partitioned to individual and higher levels (e.g., neighborhood and district); (2) How much (as a percentage) do individual-level determinants explain the variability of mental health at the individual-level; and (3) How much do determinants at the neighborhood- or district-level explain the variability of mental health at the neighborhood- or district-level? Methods: We used raw data from the second round of the Urban Health Equity Assessment and Response Tool in Tehran (in 2012-2013, n=34 700 samples nested in 368 neighborhoods nested in 22 districts) and the results of the official report of Tehran's Center of Studies and Planning (in 2012-2013, n=22 districts). Multilevel linear regression models were used to answer the study questions. Results: Approximately 40% of Tehran residents provided responses suggestive of having mental health disorders (30-52%). According to estimates of residual variance, 7% of mental health variance was determined to be at the neighborhood-level and 93% at the individual-level. Approximately 21% of mental health variance at the individual-level and 49% of the remaining mental health variance at the neighborhood-level were determined by determinants at the individual-level and neighborhood-level, respectively. Conclusions: If we want to make the most effective decisions about the determinants of mental health, in addition to considering the therapeutic perspective, we should have a systemic or contextual view of the determinants of mental health.

• Human Ecology Research
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• 제61권3호
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• pp.319-333
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• 2023

The purpose of this study was to examine which sibling and parent-child characteristics were associated with siblisng warmth and conflict among Korean young adults. The data came from an online survey of Koreans aged 19-34 years who had at least one sibling and two living parents. We conducted a multilevel regression analysis using data from 193 men with 305 siblings and 203 women with 286 siblings. The results showed that, for men, the levels of warmth were higher when the sibling was younger, when they received more frequent financial and instrumental support from the sibling, and when maternal favoritism was relatively lower. Women reported higher levels of warmth when the sibling was a sister, when they provided more frequent support for the sibling, when they had a more affectionate relationship with the mother, and when paternal favoritism was lower. As for sibling conflict, the number of siblings was positively associated with the levels of conflict among both men and women. Maternal affection was negatively related with conflict for men, and paternal favoritism was positively related to conflict for women. Interestingly, women's sibling warmth and conflict were both higher when the sibling was a sister, which meant that relationships between sisters tended to be ambivalent. This study contributes to our understandings of Koreans' sibling relationships in young adulthood.

• Asian Pacific Journal of Cancer Prevention
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• 제14권10호
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• pp.6019-6023
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• 2013

Lung cancer, one of the leading causes of cancer-related deaths, usually appears as solitary pulmonary nodules (SPNs) which are hard to diagnose using the naked eye. In this paper, curvelet-based textural features and clinical parameters are used with three prediction models [a multilevel model, a least absolute shrinkage and selection operator (LASSO) regression method, and a support vector machine (SVM)] to improve the diagnosis of benign and malignant SPNs. Dimensionality reduction of the original curvelet-based textural features was achieved using principal component analysis. In addition, non-conditional logistical regression was used to find clinical predictors among demographic parameters and morphological features. The results showed that, combined with 11 clinical predictors, the accuracy rates using 12 principal components were higher than those using the original curvelet-based textural features. To evaluate the models, 10-fold cross validation and back substitution were applied. The results obtained, respectively, were 0.8549 and 0.9221 for the LASSO method, 0.9443 and 0.9831 for SVM, and 0.8722 and 0.9722 for the multilevel model. All in all, it was found that using curvelet-based textural features after dimensionality reduction and using clinical predictors, the highest accuracy rate was achieved with SVM. The method may be used as an auxiliary tool to differentiate between benign and malignant SPNs in CT images.

• 대한간호학회지
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• 제45권5호
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• pp.752-760
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• 2015

Purpose: The purpose of this study was to examine the moderating mediation effect of self-esteem on the relations among adolescents' abuse experiences, depression and anxiety, and suicidal ideation. Methods: The participants were selected using secondary data from a population in the 2012 Korea Welfare Panel Survey (KOWEPS). Data were analyzed using SPSS 15.0 and SPSS Macro, and bootstrapping and hierarchical regression analysis were performed to analyze multilevel models. Results: First, analysis of the mediating effect of the adolescents' abuse showed that there was significant mediating influence between suicidal ideation and depression and anxiety. Second, hierarchical regression analysis showed that self-esteem had significant mediation effect on depression and anxiety in adolescents' suicidal ideation. Third, SPSS Macro showed that self-esteem also significantly moderated the mediating effect of adolescents' abuse experiences on suicidal ideation through depression and anxiety. Conclusion: The study results suggest that in future research on adolescent's abuse experience, the risk of suicide in depression and anxiety scores should be selected through evaluation of each individual's self-esteem scale. Coping strategies with immediate early intervention should be suggested.