• Title/Summary/Keyword: Logit Regression Analysis

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A Study on Control of Fume for Various Parameters in CO2 Welding (CO2 용접에서 용접변수의 변화에 따른 용접흄 제어방법에 관한 연구)

  • Oh, Kwang-Joong;Kim, Hyun-Soo;Shon, Byung-Hyun;Jee, Hae-Sung
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.8 no.1
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    • pp.76-87
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    • 1998
  • The concentration of welding fume was measured by 221 welders themselves in chassis frame workplace of the manufactory from February, 1, 1996 to May, 31, 1997. Welding parameters were the welding current and the distance between helmet and arc. Those two optimum conditions were proposed by excess probability analysis using logistic regression, so the best position in the workplace was proposed considering two factors to control the welding fume. The results are as followings; 1) The excess proability of welding fume TLV was over 99% in above 260 Amperes of welding current and also in below 30cm of distanced between helmet and arc. 2) The equation from logistic regression analysis using SPSS/PC+5.02 had the welding current as a independent variable and the excess of welding fume TLV as a dependent variable (p<0.05). Logit(welding fume TLV) = 0.1296 ${\times}$ wlding currnet - 28.8750 3) The equation from logistic regression analysis using SPSS/PC+5.02 had the distance between helmet and arc as a independent variable and the excess of welding fume threshold limit value a, a dependent variable (p<0.05). Logit (welding fume TLV) = -0.6809 ${\times}$ distance between helmet and arc +25.1665 4) Considering both cases or 2) and 3). the result equation is following. (p<0.05). Logit (welding fume TLV) = 0.1346 ${\times}$ welding current -0.3859 ${\times}$ distance between helmet and arc -15.7382 5) The excess probability of welding fume threshold limit value was 100% in above 240 Ampere of welding current. Thus, below 220 Ampere can be suggested to reduce the 40% number of welders who have a excess welding fume threshold limit value. 6) The excess probability of welding fume TLV was 100% in below 34cm of distance between helmet and arc. Thus, over 38cm can be suggested to reduce the 33% number of welders who have a excess welding fume TLV. 7) Considering both 5) and 6) cases, first of all, the best welding current can be 200 Ampere to have a below 15% of welding fume excess probability for the welders who works in distance of 34-37cm. Secondly, to have a below 30% excess probability of welding fume TLV, the working distance must be over 38cm in 220 Ampere and 32cm in 200 Ampere. 8) To reduce the average exposure concentration of welding fume ($8.21{\pm}5.83mg/m^3$), the movable local exhaust system equipped with flexible hoods can be used.

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Factors Influencing the Quality of Life of Rural Residents (농어촌 주민의 삶의 질 영향요인)

  • Minsoo Lee;Dongho Shin;Soon-Duck Yoon
    • Journal of Agricultural Extension & Community Development
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    • v.30 no.3
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    • pp.157-170
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    • 2023
  • This study aims to identify factors that affect the quality of life of rural residents. Data were collected from 4,000 rural residents living in rural areas. Raw data was procured from the 'Survey on Rural Well-being in 2022 in Rural Development Administration'. The main results of the ordinal logit regression analysis are as follows. First, in the case of non-farm households, female, immigrants, more educated, more healthy are more likely to be highly perceived quality of life. In the case of full-time farm households, more healthy are more likely to be highly perceived quality of life. In the case of part-time farm households, younger, married, more healthy are more likely to be highly perceived quality of life. Second, for all rural housholds(non-farmers, full-time farmers, and part-time farmers), local amenities and safety also had positive impact on perception of quality of life.

A Study on Factors Influencing Needs for Personal Assistance Service in the Workplace for People with Severe Disabilities (중증장애인의 근로지원인서비스 욕구에 영향을 미치는 요인에 관한 연구)

  • Han, Kyung-Sung
    • Korean Journal of Social Welfare
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    • v.63 no.3
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    • pp.29-53
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    • 2011
  • This paper analyzed factors to affect needs for personal assistance service in the workplace for people with disabilities. The statistical analyses adapted in this study were the Frequency Analysis, Ordered Logit Analysis, Multiple Regression Analysis. The results of analysis are summarized as follows. First, through the Frequency Analysis many people with severe disabilities in the workplace found to have a high desire of the personal assistance service in the workplace, and factors like types of disability, the degree of disability, income basis found to include in the selection criteria of personal assistance service in the workplace. Second, through Ordered Logit Analysis and Multiple Regression Analysis factors to affect needs for personal assistance service in the workplace for people with disabilities found to include factors like residential district, age, level of education, assistance activities of family. By the results of analysis, it is suggested practical implications and policy implications.

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A Logistic Regression Analysis of Two-Way Binary Attribute Data (이원 이항 계수치 자료의 로지스틱 회귀 분석)

  • Ahn, Hae-Il
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.35 no.3
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    • pp.118-128
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    • 2012
  • An attempt is given to the problem of analyzing the two-way binary attribute data using the logistic regression model in order to find a sound statistical methodology. It is demonstrated that the analysis of variance (ANOVA) may not be good enough, especially for the case that the proportion is very low or high. The logistic transformation of proportion data could be a help, but not sound in the statistical sense. Meanwhile, the adoption of generalized least squares (GLS) method entails much to estimate the variance-covariance matrix. On the other hand, the logistic regression methodology provides sound statistical means in estimating related confidence intervals and testing the significance of model parameters. Based on simulated data, the efficiencies of estimates are ensured with a view to demonstrate the usefulness of the methodology.

Empirical Analyses of the Relationships between the Factors of Residential Mobility and Preferable Residential District: The Case of Daegu (대구시 주거이동 결정요인별 선호주거지역 분석)

  • Hong, Keong-Gu
    • Journal of the Korean housing association
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    • v.19 no.6
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    • pp.73-83
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    • 2008
  • We explore what factors influence the residential choice and mobility of people, and try to figure out the preferable residential district in Deagu. Household, housing characteristics, and neighborhood environments are considered as explanatory variables to predict the residential choice and the preferable residential district, and logit regression is used for the analysis. We found age, ownership, income, property, and education level as household characteristics, building age as housing characteristics, and accessibility to park and open space, public library and shopping mall as neighborhood environments are significant in determining residential choice of people whereas housing size, accessibility to elementary school, local market, cultural facility and gymnasium are not significant. These results imply people choose the residential district according to household characteristics as they did, as well as choose according to housing characteristics and neighborhood environments which are newly issued factors.

Hypotheses Analysis about the Efficacy of University-Industry Collaboration In the Field of Information Technology -The Case of IT Mentoring System- (정보통신분야 산학협력 효과성에 대한 영향요인 분석 -IT 멘토링 사례중심으로-)

  • Lee, Jung-Mann;Ihm, Seung-Ho;Hwang, Gyu-He;Lee, Jin-Suk
    • The Journal of the Korea Contents Association
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    • v.11 no.8
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    • pp.342-352
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    • 2011
  • This study is to verify hypotheses about the efficacy and success factors of the IT Mentor project(in which 524 students participated) which is one of the most best practices in Korea. The empirical results found that all the aspects of students, industrial experts, professors, support programs and other infrastructure have certain influences on the industry-academia cooperation. In addition, logit regression model was employed to investigate the efficacy factors of industry and university's satisfaction to IT mentor system. It showed that industry's satisfaction depends on students' participation in company's projects and students' improvements of major competence.

An Analysis of Choice Behavior for Tour Type of Commercial Vehicle using Decision Tree (의사결정나무를 이용한 화물자동차 투어유형 선택행태 분석)

  • Kim, Han-Su;Park, Dong-Ju;Kim, Chan-Seong;Choe, Chang-Ho;Kim, Gyeong-Su
    • Journal of Korean Society of Transportation
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    • v.28 no.6
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    • pp.43-54
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    • 2010
  • In recent years there have been studies on tour based approaches for freight travel demand modelling. The purpose of this paper is to analyze tour type choice behavior of commercial vehicles which are divided into round trips and chained tours. The methods of the study are based on the decision tree and the logit model. The results indicates that the explanation variables for classifying tour types of commercial vehicles are loading factor, average goods quantity, and total goods quantity. The results of the decision tree method are similar to those of logit model. In addition, the explanation variables for tour type classification of small trucks are not different from those for medium trucks', implying that the most important factor on the vehicle tour planning is how to load goods such as shipment size and total quantity.

Multivariate Analysis for Clinicians (임상의를 위한 다변량 분석의 실제)

  • Oh, Joo Han;Chung, Seok Won
    • Clinics in Shoulder and Elbow
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    • v.16 no.1
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    • pp.63-72
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    • 2013
  • In medical research, multivariate analysis, especially multiple regression analysis, is used to analyze the influence of multiple variables on the result. Multiple regression analysis should include variables in the model and the problem of multi-collinearity as there are many variables as well as the basic assumption of regression analysis. The multiple regression model is expressed as the coefficient of determination, $R^2$ and the influence of independent variables on result as a regression coefficient, ${\beta}$. Multiple regression analysis can be divided into multiple linear regression analysis, multiple logistic regression analysis, and Cox regression analysis according to the type of dependent variables (continuous variable, categorical variable (binary logit), and state variable, respectively), and the influence of variables on the result is evaluated by regression coefficient${\beta}$, odds ratio, and hazard ratio, respectively. The knowledge of multivariate analysis enables clinicians to analyze the result accurately and to design the further research efficiently.

Association between perceived oral health and perceived oral symptoms among adults in Daegu (성인의 구강건강인식과 주관적 구강증상과의 관련성)

  • Lee, Hyung-Suk
    • Journal of Korean society of Dental Hygiene
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    • v.10 no.4
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    • pp.671-681
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    • 2010
  • Objectives : This study was to evaluate the association between perceived oral health and perceived oral symptoms among adults in Daegu. Methods : All 437 subjects aged 18 or more selected convenience sampling were surveyed cross-sectionally via the self-administrated questionnaire. The questionnaire was measured perceived oral symptoms and perceived oral health, and also obtained socio-demographic characteristics, oral health behaviors. To assess the crude associations, bivariate analysis were applied. For the adjusted association between perceived oral health and perceived oral symptoms, multivariate linear regression multiple regression analysis was conducted. Results : 33.2% of the adults rated their perceived oral health was good, and 30.9% as poor. Older age, low education, had peridontal disease was negatively perceived their oral health(p<0.05). As oral symptoms were more frequently perceived, the perceived oral health were negative. Among the factors of perceived oral symptoms, trouble biting/chewing, poor periodontal status, trouble of appearance of teeth were positively associated with the perceived oral health after adjusting for socio-demographic characteristics, oral health behaviors in the regression model. Age, education, income, recent dental treatment, and all perceived oral symptoms showed the highest impact of association with perceived oral health in the baseline-category logit model. Conclusions : Perceived oral health are significantly associated with perceived oral symptoms among adults in Daegu. The findings of this study will be helpful to design plans of oral health promotion in welfare institutions to increase the oral health related quality of life among the adults.

Estimating Price Elasticities of Domestic Air Transport Demand by Stated Preference Technique (Staled Preference 방법론에 의한 국내선 항공수요의 가격탄력성 추정)

  • 이성원;이영혁;박지형
    • Journal of Korean Society of Transportation
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    • v.18 no.1
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    • pp.27-34
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    • 2000
  • This study analyzes the price elasticities of airline Passenger demand through the 'Stated Preference' technique which uses survey data. Because the domestic airfare has been regulated by the government. it is not easy to derive Price elasticity through the usual regression analysis with aggregate data and thus a special methodology is required for elasticity estimation. Therefore, in this study we estimated the Price elasticities of domestic air passenger demand and the modal share change rates to the alternative modes with logit model and sample enumeration method, by analyzing the survey data on air Passengers' demand behavior about the mode choice between air-rail. air-bus, and air-car. As the results, the estimated price elasticities are in the range of -0.6~-0.9, and rail is mainly chosen as an alternative mode. bus is chosen Partly, and car is barely used.

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