• Title/Summary/Keyword: Stepwise regression

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Development of Variable Selection Technique using Stepwise Regression and Data Envelopment Analysis (단계적 회귀법과 자료봉합분석을 이용한 변수선택기법의 개발)

  • Jeong, Min-Eui;Yu, Song-Jin
    • Journal of KIISE:Software and Applications
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    • v.41 no.8
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    • pp.598-604
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    • 2014
  • In this paper, we develop stepwise regression data envelopment model to select important variables. We formulate null hypothesis to understand the importance of each variable and use Kruskal-Wallis test for this purpose. If the Kruskal-Wallis test does reject the null hypothesis this will imply there is significant fluctuation in the efficiency score relative to base model. And therefore we have to further check the pair of variables that causes the fluctuation in order to determine its importance using Conover-Inman test. The proposed models helps understand the extent of misclassification decision making units as efficient/inefficient when variables are retained or discarded alongside provides useful managerial prescription to make improvement strategies.

Relationships between Anger Expression, Social Supports and Adjustment to College Life among Nursing Students (간호대학생의 분노표현방식, 사회적지지 및 대학생활적응의 관계)

  • Jun, Won-Hee;Jo, Myoung-Ju;Na, Hyunjoo
    • The Journal of the Korea Contents Association
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    • v.15 no.3
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    • pp.219-228
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    • 2015
  • The purpose of this study was to examine the relationships between anger expression, social supports, and adjustment to college life among nursing students. A convenience sample of 266 students in two colleges participated in the study. Data were analyzed using t-tests, ANOVA, Pearson correlation coefficients, and multiple stepwise regression. The mean score for adjustment to college life was above average. The mean score for adjustment to college life differed significantly according to students' reasons for applying to college and perceived health status. Adjustment to college life significantly correlated with anger expression and social supports. Multiple stepwise regression analysis showed that anger expression (Anger-Out, Anger-In, and Anger-Control), social supports, and perceived health status explained 27.1% of the variance in adjustment to college life. The study findings suggest that interventions intended to promote nursing students' adjustment to college life should focus on improving anger management, social supports, and perceived health status.

Converged Influencing Factors of Health Promotion Behaviors, Menopausal Symptoms and Wisdom in the Middle-Aged Women on Health Conservation (중년여성의 건강증진행위, 갱년기증상, 지혜가 건강보존에 미치는 융합적 영향요인)

  • Lee, Hyea-Kyung;Shin, Eun-Hee;Kim, Yeon-Kyung
    • Journal of Digital Convergence
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    • v.14 no.11
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    • pp.597-605
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    • 2016
  • This study aimed to examine the multiple factors to affect the health conservation in the middle aged women. The subjects were 143 middle aged women from 40 to 59 years old and the data collection period was from June 1 to 25, 2016. The data was analyzed by descriptive statistics, t-test, ANOVA, Pearson's correlation coefficients, and stepwise multiple regression. We found a significantly positive association between health conservation and health promotion behaviors among middle-aged women. However, menopausal symptoms and wisdom were not significantly associated with health conservation. Stepwise multiple regression analysis was performed to analyze the most correlation variables were health enhancement behaviors with 12.5% and existence of spouse with 3.2%. This study provides more ensured fundamental data for the health conservation and enhancement in the middle aged women.

Effect of Self Efficacy and Self Leadership on Stress in Adolescents (청소년의 자기효능감 및 셀프리더십이 스트레스에 미치는 영향)

  • Kim, Nam-Hee;Lee, Hea-Shoon
    • The Journal of the Korea Contents Association
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    • v.15 no.1
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    • pp.211-220
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    • 2015
  • Purpose: The purpose of this study was to identify the effect of self efficacy and self leadership on stress in adolescents. Methods: Data were collected from 722 adolescents and analyzed using descriptive statistics, t-test, ANOVA, Scheffe's test, Pearson correlation coefficients and stepwise multiple regression with the SPSS 20.0 program. Results: Stress differed according to gender, grade, economic level. Self efficacy and self leadership had a significant negative correlation with stress. Stepwise multiple regression analysis showed self efficacy(general self efficacy), self leadership(cognitive strategies), gender(female), grade(high school) explained 32.5% of the total variance in stress. The findings indicate that self efficacy and self leadership had an influence on stress. Conclusions: The results of this study offer basic data for the development of intervention programs to prevent adolescents stress.

A Study of the Relation between Quality of Life and Family Burden of Home-based Hospice Patient Families (재가 호스피스환자 가족의 삶의 질과 가족부담과의 관계)

  • Lee, Eun-Ju;Kim, Hyang-Dong
    • Korean Journal of Hospice Care
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    • v.6 no.2
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    • pp.69-78
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    • 2006
  • Purpose: This study was conducted to analysis relationship about quality of life and family burden of the home-based hospice patient families. Method: The subjects consisted of 94 families with home-based hospice patient. The ages of the subjects were 17-73 years with hospice patient who receivedhome visiting care and registered at 4 hospitals in Daegu and Kyung-Buk. The data was collected from March to November 2004. The instruments used for the study were Quality of Life Scale (GLS) and Family Burden Questionnaire (FBQ). The analysis was done using frequency, mean, standard deviation, correlation and stepwise multiple regression with SPSS WIN 11.0. Results: The results were as follows: 1. The mean score of family burden was 3.36 ($\pm0.55$). The highest mean score of family burden 6 factors were wellness of future 3.85($\pm1.10$), and the second was economic family burden 3.63($\pm0.97$). 2. The mean score of quality of life was 3.09 ($\pm0.48$). The lowest score of quality of life 6 factors were economic status 2.86($\pm0.54$), and the second was physical state and function 3.01($\pm0.62$). 3. In the home-based hospice patient families, family burden had significant negative correlation with quality of life(r=-0.25, p=0.012). 4. Emotional status accounted for 11% of family burden in the home-based hospice patient families by means of stepwise multiple regression. 5. Economical status accounted for 18 and age accounted for an additional 11% of quality of life in the home-based hospice patient families by means of stepwise multiple regression. Conclusion: The finding showed that family burden and quality of life of home-based hospice patient families were significantly negative correlation and the highest factor of family burden was wellness of future and the most important factor of quality of life was economic status.

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Effects of Empowerment and Regarding Standard Precautions for Healthcare associated Infection Control in Nursing Students Experiencing Clinical Practice on Performances (임상실습을 경험한 간호대학생의 임파워먼트와 의료관련감염 관리 표준주의지침 인지도가 수행도에 미치는 요인)

  • Jung, Mi-Ra;Jeong, Eun
    • Journal of Digital Convergence
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    • v.17 no.1
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    • pp.259-267
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    • 2019
  • The purpose of this study was to examine relationships among empowerment, awareness and performance on standard precautions and identify the factors that affect performance of standard precaution in nursing students experiencing clinical practice. The data were collected from 168 nursing students who experienced clinical practice in the two colleges located Jeonnam. The data were analyzed by descriptive statistics, t-test, ANOVA, Scheffe, Pearson's correlation coefficient, and stepwise multiple regression with SPSS 20.0 program. The result of the stepwise multiple regression indicates the awareness predict 77.7% (F=579.84, p<.001) in the performance of standard precaution. Therefore, it is necessary to develop awareness of the standard precaution strategy program for improving the performance of standard precautions in nursing students experiencing clinical practice.

Analysis of Temperature Effect on Activated Sludge Process at Cheong-Gye Cheon Sewage Treatment Plant (활성오니공법에 있어서 수온이 처리효율에 미치는 영향에 관한 분석 -청계천 하수종말처리장에 대하여-)

  • 이은경
    • Journal of Environmental Health Sciences
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    • v.7 no.1
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    • pp.9-20
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    • 1981
  • This study was performed to determine the correlationship between temperature and overall removals of BOD, SS and to demonstrate the effect of temperature on treatment performance. These data for a period from February 1, 1977 to January 31, 1980 were obtained from the Cheong-Gye Cheon Sewage Treatment plant. The results of correlation and stepwise multiple regression analysis were as follows. 1) Secondary effluent BOD and SS showed negative correlationship with water temperature, with correlation coefficient of -0.1710, and -0.1654 respectively. 2) Correlation coefficient of BOD, SS removal rate and water temperature were 0.1823 and 0.0429 respectively. 3) Regresion equation for estimate of BOD removal rate was as follows $\widehat{Y}_1$ (BOD removal rate)=63.9994+0.5442X(water temperature). And BOD removal rate showed non significant change according to the water temperature. 4) Regression equation for estimate of SS removal rate was as follows $\widehat{Y}_2$ (SS removal rate)=61.6881+0.1514X(Water temperature). And SS removal rate showed non significant change according to the water temperature. 5) According to the Stepwise Multiple Regression analysis, water temperature ranked second order in the BOD removal rate estimation and the equation was as follows $\widehat{Y}_1$ (BOD removal rate)=69.7398+0.2665 $X_1$ (Primary effluent BOD)+0.3562 $X_2$ (Water temperature)-0.0122 $X_3(Flow)+4413.271X_4$ (Organic Loading).

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The Effect of Vitamin D and Calcium on Cognitive Function and Depression in the Elderly Living in a City

  • Lee, Yu-Jin;Kim, Yun-Su
    • Research in Community and Public Health Nursing
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    • v.28 no.3
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    • pp.251-259
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    • 2017
  • Purpose: This study aims to examine the influence of vitamin D and calcium on depression and cognitive function of the elderly living alone in a city. Methods: The participants were registered in eight senior centers in S city and they had lived alone. Data were collected between November 28, 2014 and March 7, 2015. A total of 155 people participated in data collection to measure the serum vitamin D, the serum calcium, depression, and cognitive function. The data were analyzed with t-test, ANOVA, Pearson's correlation and multiple regression analysis. Results: There were significant differences in depression according to gender and perceptions of health status. Depression correlated significantly with the serum calcium and perceptions of health status, and a stepwise regression analysis showed that the perceptions of health status were significant. There were significant differences in cognitive function according to education level and age. Cognitive function correlated significantly with the serum vitamin D and a stepwise regression analysis showed that education level and age were significant. Conclusion: Consequently, elderly people with poor perceptions of their health status need a depressive intervention program and those with a higher age and lower level of education need a cognitive function intervention program.

Developing a Molecular Prognostic Predictor of a Cancer based on a Small Sample

  • Kim Inyoung;Lee Sunho;Rha Sun Young;Kim Byungsoo
    • Proceedings of the Korean Statistical Society Conference
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    • 2004.11a
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    • pp.195-198
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    • 2004
  • One Important problem in a cancer microarray study is to identify a set of genes from which a molecular prognostic indicator can be developed. In parallel with this problem is to validate the chosen set of genes. We develop in this note a K-fold cross validation procedure by combining a 'pre-validation' technique and a bootstrap resampling procedure in the Cox regression . The pre-validation technique predicts the microarray predictor of a case without having seen the true class level of the case. It was suggested by Tibshirani and Efron (2002) to avoid the possible over-fitting in the regression in which a microarray based predictor is employed. The bootstrap resampling procedure for the Cox regression was proposed by Sauerbrei and Schumacher (1992) as a means of overcoming the instability of a stepwise selection procedure. We apply this K-fold cross validation to the microarray data of 92 gastric cancers of which the experiment was conducted at Cancer Metastasis Research Center, Yonsei University. We also share some of our experience on the 'false positive' result due to the information leak.

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Developing an Biomechanical Functional Performance Index for Parkinson's Disease Patients (한국형 파킨슨 환자의 역학적 기능수행지수 개발)

  • Shin, Sunghoon;Han, Byungin;Chung, Chulmin;Lee, Yungon
    • Korean Journal of Applied Biomechanics
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    • v.30 no.1
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    • pp.83-91
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    • 2020
  • Objective: The study aimed to develop a functional performance index that evaluates the functional performance of Parkinson's patients, i.e., to integrate biomechanical measurements of walking, balance, muscle strength and tremor, and to use multiple linear regression with stepwise methods to identify the most suitable predictors for the progression of disease. Method: A total of 60 subjects were tested for sub-variables of four factors: walking, balance, isometric strength and hand tremors. Potential independet variables were extracted through correlation analysis of the sub-variables and dependent variables, Hoehn & Yahr scale. And then, a stepwise multiple regression analysis using the potential independent variables was performed to identify predictor of Hoehn & Yahr scale. Results: First, the results of the study showed that physical composition and gait had a relatively more correlated with the progression of the disease, compared to balance and hand tremor. Second, Parkinson's functional performance is characterized by dynamic pattern of walking, such as foot clearance and turning angle (TA) of walking, and a high-explained regression model is completed. Conclusion: The study emphasized the importance of walking variables and body composition in minor pathological features compared to Parkinson's patient's balancing ability and hand tremor. Specifically, it revealed that dynamic walking patterns functionally characterize patients. The results are worth considering when assessing functional performance related to the progression of the disease at the site.