• 제목/요약/키워드: multiple regression function

검색결과 538건 처리시간 0.029초

Empirical seismic fragility rapid prediction probability model of regional group reinforced concrete girder bridges

  • Li, Si-Qi;Chen, Yong-Sheng;Liu, Hong-Bo;Du, Ke
    • Earthquakes and Structures
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    • 제22권6호
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    • pp.609-623
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    • 2022
  • To study the empirical seismic fragility of a reinforced concrete girder bridge, based on the theory of numerical analysis and probability modelling, a regression fragility method of a rapid fragility prediction model (Gaussian first-order regression probability model) considering empirical seismic damage is proposed. A total of 1,069 reinforced concrete girder bridges of 22 highways were used to verify the model, and the vulnerability function, plane, surface and curve model of reinforced concrete girder bridges (simple supported girder bridges and continuous girder bridges) considering the number of samples in multiple intensity regions were established. The new empirical seismic damage probability matrix and curve models of observation frequency and damage exceeding probability are developed in multiple intensity regions. A comparative vulnerability analysis between simple supported girder bridges and continuous girder bridges is provided. Depending on the theory of the regional mean seismic damage index matrix model, the empirical seismic damage prediction probability matrix is embedded in the multidimensional mean seismic damage index matrix model, and the regional rapid prediction matrix and curve of reinforced concrete girder bridges, simple supported girder bridges and continuous girder bridges in multiple intensity regions based on mean seismic damage index parameters are developed. The established multidimensional group bridge vulnerability model can be used to quantify and predict the fragility of bridges in multiple intensity regions and the fragility assessment of regional group reinforced concrete girder bridges in the future.

서울시 일부 고등학생의 정신건강에 영향을 미치는 요인 (Influential Factors on Mental Health of High School Students in Seoul)

  • 최미경
    • 보건교육건강증진학회지
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    • 제22권4호
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    • pp.155-166
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    • 2005
  • Objectives: The purpose of this study was to examine factors influencing the mental health of high school students in relation to sociodemographic variables, family function, self-esteem, social support, and self-identity. Methods: The survey was carried out on a convenience sample of 332 high school students. Data analysis procedure included stepwise regression using mental health as the dependent variable, and sociodemographics, family function, self-esteem, social support, and self-identity, as independent variables. Results: Stepwise multiple regression revealed that the factors such as self-esteem(${\beta}=0.422$, p<0.001), self-identity(${\beta}=0.166$, p<0.001), and sex(${\beta}=-0.165$, p<0.001) turned out to be significant affecting factors. Twenty seven percent of varience in mental health was explained by these factors(22% of varience by self-esteem). Conclusion: Self-esteem was turned out to be the most important effective factor of mental health in high school students. These results suggest that it is important for high school students to promote their self-esteem to keep their good mental health.

Lifestyle Habits Associated with Poor Defecation Habit among Pupils in Japan

  • Kohyama, Jun
    • Pediatric Gastroenterology, Hepatology & Nutrition
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    • 제23권6호
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    • pp.567-576
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    • 2020
  • Purpose: Not enough attention has been paid to defecation habits in Japan. This study aimed to emphasize the importance of defecation habits on health and function in Japanese pupils. Methods: Using multiple regression analysis, 2,722 questionnaires obtained from pupils in grades 5 to 12 were analyzed to determine lifestyle habits associated with defecation frequency. Results: Significant regression formulae for defecation scores were obtained for all school types: elementary school (ES) (adjusted R2=0.08, p<0.001), junior high school (JHS) (0.09, p<0.001), and senior high school (SHS) (0.15, p<0.001). The following factors were associated with poorer defecation scores, according to school type: female gender (all 3 school types), breakfast skipping (elementary and JHSs), lower physical activity (JHSs and SHSs), and longer school-day screen time (elementary and SHSs). In addition, poorer self-reported academic performance scores in ES, less standardized body mass index (BMI) in JHS, and shorter non-school- day screen time scores in SHS, were associated with poorer defecation scores. Conclusion: Poor defecation frequency showed significant associations with various lifestyle habits, such as breakfast skipping, physical activity, and screen time, among pupils. Academic performance and standardized BMI were also associated with defecation frequency. More attention should be paid to defecation frequency to sustain health and function in pupils.

Statistical Approach for Corrosion Prediction Under Fuzzy Soil Environment

  • Kim, Mincheol;Inakazu, Toyono;Koizumi, Akira;Koo, Jayong
    • Environmental Engineering Research
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    • 제18권1호
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    • pp.37-43
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    • 2013
  • Water distribution pipes installed underground have potential risks of pipe failure and burst. After years of use, pipe walls tend to be corroded due to aggressive soil environments where they are located. The present study aims to assess the degree of external corrosion of a distribution pipe network. In situ data obtained through test pit excavation and direct sampling are carefully collated and assessed. A statistical approach is useful to predict severity of pipe corrosion at present and in future. First, criteria functions defined by discriminant function analysis are formulated to judge whether the pipes are seriously corroded. Data utilized in the analyses are those related to soil property, i.e., soil resistivity, pH, water content, and chloride ion. Secondly, corrosion factors that significantly affect pipe wall pitting (vertical) and spread (horizontal) on the pipe surface are identified with a view to quantifying a degree of the pipe corrosion. Finally, a most reliable model represented in the form of a multiple regression equation is developed for this purpose. From these analyses, it can be concluded that our proposed model is effective to predict the severity and rate of pipe corrosion utilizing selected factors that reflect the fuzzy soil environment.

학령기 정상 아동의 호흡 특성과 신체 조건에 관한 상관분석 (Analysis of Correlation between Respiratory Characteristics and Physical Factors in Healthy Elementary School Childhood)

  • 이혜영;강동연;김경
    • The Journal of Korean Physical Therapy
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    • 제25권5호
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    • pp.330-336
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    • 2013
  • Purpose: Respiratory is an essential vital component for conservation of life in human, which is controlled by respiratory muscles and its related neuromuscular regulation. The purpose of this study is to assess lung capacity and respiratory pressure in healthy children, and to investigate relationship and predictability between respiratory pressure and other related respiratory functions. Methods: A total of 31 healthy children were recruited for this study. Demographic information and respiratory related factors were assessed in terms of body surface area (BSA), chest mobility, lung capacity, and respiratory pressure. Correlation between respiratory pressure and the rested variables was analyzed, and multiple regression using the stepwise method was performed for prediction of respiratory muscle strength, in terms of respiratory pressure as the dependent variable, and demographic and other respiratory variables as the independent variable. Results: According to the results of correlation analysis, respiratory pressure showed significant correlation with age (r=0.62, p<0.01), BSA (r=0.80, p<0.01), FVC (r=0.80, p<0.01), and FEV1 (r=0.70, p<0.01). In results of multiple regression analysis using the backward elimination method, BSA and FVC were included as significant factors of the predictable statistical model. The statistical model showed a significant explanation power of 71.8%. Conclusion: These findings suggest that respiratory pressure could be a valuable measurement tool for evaluation of respiratory function, because of significant relationship with physical characteristics and lung capacity, and that BSA and FVC could be possible predictable factors to explain the degree of respiratory pressure. These findings will provide useful information for clinical assessment and treatment in healthy children as well as those with pulmonary disease.

일부 가철성 의치장착 노인의 의치만족도 영향 요인 (Influencing factors of removable denture satisfaction in the elderly)

  • 윤혜정;임선아;정은주
    • 한국치위생학회지
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    • 제15권3호
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    • pp.435-442
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    • 2015
  • Objectives: The purpose of this study was to investigate the influencing factors of removable dentures satisfaction in the elderly. Methods: A self-reported questionnaire was filled out by 256 elderly in Jeollanam-do from September 1, 2013 to June 30, 2014. The questionnaire consisted of general characteristics of the subjects, denture related characteristics systemic health characteristics and dental health behavior. Removable dentures satisfaction was adapted from Ban. The questionnaire for Removable dentures satisfaction included general treatment satisfaction, masticatory function satisfaction, denture retention satisfaction, aesthetic satisfaction measured by Likert 5 scale. Cronbach's alpha was 0.850 in the study. Data were analyzed for a t-test, one-way ANOVA and multiple regression analysis by using SPSS(SPSS 18.0, USA) program. Results: According to subjective and systemic health condition and oral health condition, there was a statistically significant increase in general satisfaction of treatment, masticatory satisfaction of function, denture satisfaction of retention, aesthetic satisfaction. The overall satisfaction for removable denture showed a significant improvement. In the multiple regression analysis, variation of removable denture satisfaction was positively associated with oral health status{good(b=0.736, p=0.000)}, denture treatment services{dental hospital clinic(b=0.327, p=0.023)}, and systemic health status{good(b=0.241, p=0.047)}. Conclusions: Satisfaction of removable dentures may have a positive impact on oral health condition, hospital type, and associated systemic disease. It is necessary to develop incremental care programs for oral health and systemic health and to make public opinion to encourage the program.

농촌지역 노인들의 우울 및 인지기능장애에 관한 연구 (A Study on the Depression and Cognitive Impairment in the Rural Elderly)

  • 이정애;정향균
    • Journal of Preventive Medicine and Public Health
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    • 제26권3호
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    • pp.412-429
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    • 1993
  • For the purpose of promotion of mental health in the rural elderly, the author surveyed 558 elderlies aged 60 years or more, and assessed the prevalence rates of depression and cognitive impairment by using self-rating depression scale of Zung (SDS) and the Korean version of mini-mental state examination (MMSEK). Also the association between depression or cognitive function and socio-environmental factors were investigated. The major findings were as follows ; 1. The prevalence rates of severe depression and cognitive impairment were 20.9% and 14.9% in all the elderly of both sexes, respectively. 2. The rates of depression and cognitive impairment increased with increasing age in both sex groups. The mean scores of SDS increased and the mean scores of MMSEK decreased significantly among them (p<0.01). 3. Those being female, widows or widowers, and those having low levels of physical activity, showed significantly high the mean scores of depression and had significantly low the mean scores of cognitive impairment (p<0.01). 4. The depression scores relating to decreased libido, confusion, psychomotor retardation, hopelessness and indecisiveness were relatively high in both sexes. 5. All the items of mini-mental state examination were significantly correlated with depression. 6. In stepwise multiple regression analysis on depression, MMSEK, level of physical activity, chronic disease, marital status and family income were selected as highly correlated variables, and the $R^2$-value for these variables was 33.7%. 7. In stepwise multiple regression analysis on cognitive function, level of physical activity, age, depression, sex and marital status were selected as highly correlated variables, and the $R^2$-value for these variables was 62.6%. The depression and cognitive impairment of the elderly were positively correlated with nearly all sociodemographic variables.

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치매환자의 간호의존도 영향요인 (Factors Influencing Care Dependency in Patients with Dementia)

  • 김은주
    • 대한간호학회지
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    • 제33권6호
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    • pp.705-712
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    • 2003
  • Purpose: The purpose of this study was to explore factors that influence care dependency of institutionalized patients with dementia. Method: This study utilized descriptive correlational design. The convenience sample was composed of 110 residents with dementia of two long-term care facilities in Korea. Stepwise multiple regression was used to identify significant factors influencing care dependency in patients with dementia. Care dependency was measured using the Care Dependency Scale, Korean version(CDS-K). Cognition was measured by the MMSE-K. Functional disability was measured by the PULSES Profile. Behavioral dysfunction was measured by the modified E-BEHAVE AD. Result: Care dependency was significantly influenced by cognition, functional disability, behavioral dysfunction, and duration of dementia. This regression model explained 61 % of the variances in care dependency. Cognition explained 37% of the variances, and functional disability explained 21% of the variances. Conclusion: Results of this study suggest that professional caregivers intervene more effectively in caring for their patients with dementia by recognizing the patients cognitive, functional, behavioral disability, and its periodic change. Individually, remaining abilities-focused intervention should be applied to enhance patient to be dependent and to prevent unnecessary independency.

The Scale Ratio Testing of Multiple Outliers in Linear Regression

  • Park, Jin-Pyo
    • Journal of the Korean Data and Information Science Society
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    • 제14권3호
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    • pp.673-685
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    • 2003
  • In this paper we consider the problem of identifying and testing outliers in linear regression. First we consider the problem for testing the null hypothesis of no outliers. A test based on the ratio of two residual scale estimates is proposed. We show the asymptotic distribution of the test statistics by Monte Carlo simulation and investigate its properties. Next we consider the problem of identifying the outliers. A forward sequential procedure using the suggested test is proposed and shown to perform fairly well. Unlike other forward procedures, the present one is unaffected by masking and swamping effects because the test statistic is based on robust scale estimate.

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The Forward Sequential Procedure for the Identifying Multiple Outliers in Linear Regression

  • Park, Jin-Pyo
    • Journal of the Korean Data and Information Science Society
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    • 제16권4호
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    • pp.1053-1066
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    • 2005
  • In this paper we consider the problem of identifying and testing outliers in linear regression. First we consider the use of the so-called scale ratio tests for testing the null hypothesis of no outliers. This test is based on the ratio of two residual scale estimates. We show the asymptotic distribution of the test statistics and investigate its properties. Next we consider the problem of identifying the outliers. A forward sequential procedure using the suggested test is proposed. The new method is compared with classical procedure in the real data example. Unlike other forward procedures, the present one is unaffected by masking and swamping effects because the test statistic is based on robust scale estimate.

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