• Title/Summary/Keyword: Multiple-Linear-Regression

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Patterns and Interrelationships for Meeting Recommendations of Physical Activity, and Sedentary and Dietary Behavior in Elementary School Students (초등학생의 신체활동, 좌식행동, 식이행동에 대한 권고사항 실천 패턴 및 상호관련성)

  • Kim, Jae-Woo;Kong, Sung-A;Lee, On;Jin, Cheng-Zhu;Kim, Yeon-Soo
    • The Korean Journal of Community Living Science
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    • v.20 no.1
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    • pp.81-89
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    • 2009
  • The purpose of this study was to analyze the patterns and interrelationships for meeting recommendations of physical activity, sedentary behavior, and dietary behavior in elementary school students. A cross-sectional design was used to assess 259 students ages 11 to 13 years. Physical activity (moderate to vigorous physical activity $\geqq$60min/day), sedentary behavior (viewing time for TV, computer, DVD, video, etc<3hr/day), and dietary behavior (servings of fruits and vegetables$\geqq$5times/day) were categorized into two levels: meeting recommendations or not meeting recommendations. Parents' health behaviors and home environmental variables were assessed with self-reported measures. Chi-squared tests and independent t-tests were conducted to compare anthropometric variables and the prevalence of students not meeting the recommendation for the three health behaviors. Comparison between males and females and logistic linear regression were used to determine the interrelationships of three health behaviors. 25.9% of students did not meet the physical activity recommendations. 15.4% did not meet sedentary behavior recommendations, and 41.7% did not meet dietary recommendation. Only 39.8% of students met all three recommendations, but 19.0% did not meet over two recommendations. Patterns that simultaneously did not meet two recommendations were: sedentary and dietary behavior in males (8.1%), and physical activity and dietary behavior in females (10.4%). Students who did not meet dietary recommendations were at greater risk of not meeting physical activity (OR 2.76; 95% CI 1.15 to 6.64), and sedentary behavior (OR 3.07; 95% CI 1.15 to 8.16) compared with students who did meet dietary recommendations. The findings of this study support not an independent behavior approach but a multiple behavior approach taking into account gender and interrelationships among the three behaviors.

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The Assessment of Acquired Dyschromatopsia among Organic-Solvents Exposed Workers (유기용제 폭로작업자들의 후천성 색각이상 평가)

  • Kang, Mi-Jung;Kang, Su-Hee;Suh, Suk-Kwon;Shin, Dong-Hoon;Lee, Jong-Young
    • Journal of Preventive Medicine and Public Health
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    • v.29 no.3 s.54
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    • pp.529-538
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    • 1996
  • We investigated the occurrence of color vision loss in 70 organic solvent mixtures exposed workers and in 47 controls. Color Vision was assessed with a color arrangement test designed to identify the defective color sense, the Han Double 15-Hue Test. The results of the test were no significant difference between exposed workers and controls in the proportion of subjects who committed one or two errors. Quantitative analysis, using color confusion index(CCI), showed no signicant difference between exposed workers and controls. A significant linear correlation was present between age and CCI in both exposed workers (CCI=0.0056age + 0.94; r=0.23; p<0.05) and controls(CCI=0.0066age + 0.86; r=0.33; p<0.05). Qualitative analysis of the patterns on the hue circle showed that the prevalence of acquired dyschromatopsia was 21% in both and no significant difference. Multiple regression analyses showed that age was significantly related to color vision loss. These results did not provide evidence of a relationship between organic solvents exposure and incidence of color vision loss. In field studies for monitor the people at risk of the acquired color vision loss involving low-dose organic solvents exposed workers, both quantitative and qualitative information should be considered.

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A Study on the Safety-Maximizing Design of Exclusive Bus Lanes (안전성 제고를 위한 버스전용차로 디자인 연구)

  • Yang, Chul-Su
    • Journal of Korean Society of Transportation
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    • v.30 no.4
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    • pp.21-32
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    • 2012
  • Exclusive bus lane (EBL) is typically located in the roadway median, and is accessed by weaving across the GPLs(general purpose lanes) before entering from the left lane of the GPLs. To maximize the potential for successful EBL operations, a critical design issue that requires special attention is the length of bus weaving section before entering EBL. The process of developing guidelines for the length of bus weaving section can be supported by a sensitivity analysis of performance measure (safety) with respect to the bus weaving distance. However, field data are difficult to obtain due to inherent complexity in creating performance measure (safety) samples under various interesting flows and bus weaving distance that are keys to research success. In this paper, VISSIM simulation is applied to simulate the operation of roadway weaving areas with EBL, and based on vehicle trajectory data from microscopic traffic simulation models, the Surrogate Safety Assessment Model (SSAM) computes the number of surrogate conflicts (or degree of safety) with respect to the bus weaving distance. Then, a multiple linear regression (MLR) model using safety data (number of surrogate conflicts) is developed. Finally, guidelines for bus weaving distance are established based on the developed MLR. Developed guidelines explicitly indicate that a longer bus weaving distance is required to maintain desired safety as weaving volume increases.

Development of Predicting Models of the Operating Speed and Operating environment Satisfaction Model in Expressways (고속도로의 주행속도예측 및 주행환경만족도 모형 개발에 관한 연구)

  • Kim, Jang-Uk;Jang, Il-Jun;Kim, Jeong-Hyeon;Lee, Su-Beom
    • Journal of Korean Society of Transportation
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    • v.27 no.2
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    • pp.117-131
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    • 2009
  • When most drivers take to the freeway, they don't necessarily pay attention to the geometric design. They expect proper design by depending on their own senses and recognition. When they evaluate the features of traveling on the freeway, they can think differently than engineers. The design needs to predict the exact speed of the driver to satisfy the driver's expectation, safety, pleasure and so on. This study categorized the factors influencing the speed of six freeways considering geometric and operational features to make a prediction model of speed. The model used multiple regression with these factors and produced statically appropriate results. This study utilized the principle component analysis and the quantification II analysis based on the image data of the satisfaction of the traveling environment collected through individual interviews. As a result, this study found the factors of satisfaction in a traveling environment. It made a satisfaction model of the traveling environment on freeways considering the change of driver's actual recognition and societal recognition using structural equations and the quantification II theory. Through the model made in this study, This model can present not only qualitative factors like satisfaction of traveling environment on freeways, but also the quantitative elements like speed. What is important is the evaluation of features of traveling on freeways reflected in the recognition and traffic environment felt by drivers.

Analysis of Within-Field Spatial Variation of Rice Growth and Yield in Relation to Soil Properties

  • Ahn Nguyen Tuan;Shin Jin Chul;Lee Byun-Woo
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.50 no.4
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    • pp.221-237
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    • 2005
  • For developing the site-specific fertilizer management strategies of crop, it is essential to know the spatial variability of soil factors and to assess their influence on the variability of crop growth and yield. In 2002 and 2003 cropping seasons within-field spatial variability of rice growth and yield was examined in relation to spatial variation of soil properties in the· two paddy fields having each area of ca. $6,600m^2$ in Suwon, Korea. The fields were managed without fertilizer or with uniform application of N, P, and K fertilizer under direct-seeded and transplanted rice. Stable soil properties such as content of clay (Clay), total nitrogen (TN), organic mater (OM), silica (Si), cation exchange capacity (CEC), and rice growth and yield were measured in each grid of $10\times10m$. The two fields showed quite similar spatial variation in soil properties, showing the smallest coefficient of variation (CV) in Clay $(7.6\%)$ and the largest in Si $(21.4\%)$. The CV of plant growth parameters measured at panicle initiation (PIS) and heading stage (HD) ranged from 6 to $38\%$, and that of rice yield ranged from 11 to $21\%$. CEC, OM, TN, and available Si showed significant correlations with rice growth and yield. Multiple linear regression model with stepwise procedure selected independent variables of N fertilizer level, climate condition and soil properties, explaining as much as $76\%$ of yield variability, of which $21.6\%$ is ascribed to soil properties. Among the soil properties, the most important soil factors causing yield spatial variability was OM, followed by Si, TN, and CEC. Boundary line response of rice yield to soil properties was represented well by Mitcherich equation (negative exponential equation) that was used to quantify the influence of soil properties on rice yield, and then the Law of the Minimum was used to identify the soil limiting factor for each grid. This boundary line approach using five stable soil properties as limiting factor explained an average of about $50\%$ of the spatial yield variability. Although the determination coefficient was not very high, an advantage of the method was that it identified clearly which soil parameter was yield limiting factor and where it was distributed in the field.

Analysis of the factors associated with awareness of community water fluoridation program (수돗물불소농도조정사업에 대한 인지도와 관련요인 분석)

  • Kim, Yu-Jin;Baek, So-Yeong;An, Se-Yeon;Lee, Mi-Hui;Lee, Seon-Yeong;Lee, Yeon-Ju;Lee, Yu-Ri;In, Mi-Hui;Han, Da-Eun;Choi, Jun-Seon
    • Journal of Korean society of Dental Hygiene
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    • v.12 no.5
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    • pp.871-879
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    • 2012
  • Objectives : The purpose of this study was to investigate the factors related to the awareness level of community water fluoridation program. Methods : 700 subjects were surveyed among the residents living in Incheon Metropolitan City. Data were collected on awareness of community water fluoridation program, general factors, oral health behavior, self-reported oral health and oral health interest. The factors related to the awareness level of community water fluoridation program were analyzed by t-test, a one way ANOVA and multiple linear regression analysis. Results : 1. Subjects' ages were 40~59 years, monthly average incomes were more than 3 million won and higher their educational levels had a higher awareness level of community water fluoridation program(p<0.01). 2. People who brushed their teeth more than three times a day, used oral hygiene devices, and had periodic oral examination and removed plaques were had higher awareness level of community water fluoridation program(p<0.01). Especially, the use of oral hygiene devices was the strongest factor in relation with the awareness level of community water fluoridation program(p<0.01). 3. People who had a fine self-reported oral health, highly interested in dental hygiene and made an effort to keep oral health were had higher awareness level of community water fluoridation program(p<0.001). Conclusions : The awareness level of community water fluoridation program was related to oral health behavior, self-reported oral health and oral health interest. So, in order to expand the areas for community water fluoridation program, it is important to educate to the right information about objectives, safety, dental caries preventing effect of the community water fluoridation program. And the education and publicity on general oral health will have an affirmative effect on expanding community water fluoridation program.

Factors Influencing Limerence in Dating Relationships among Female College Students (여대생을 대상으로 한 이성 교제의 집착 행동에 영향을 주는 요인)

  • Kim, Oksoo;Jeon, Hae Ok
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.2
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    • pp.304-314
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    • 2020
  • This cross-sectional descriptive study investigated the influence of romantic relationships' characteristics, self-esteem and sexual autonomy on limerence in dating relationships among female college students who had or were currently engaged in a dating relationship. The data was collected through self-reported structured questionnaires from 167 female Korean college students using convenient sampling methods from November 25, 2012 to December 20, 2012. The data was analyzed using t-tests, one-way analyses of variance, Scheffe's test, Pearson's correlation coefficients, and multiple linear regression analysis with the IBM SPSS 23.0 program. The results showed that a significant difference was found in limerence according to the frequency of experiencing romantic breakup (F=4.16, p=.003), and limerence in dating relationships was negatively correlated with self-esteem (r=-.31, p<.001) and sexual autonomy (r=-.21, p=.006). Self-esteem and the frequency of romantic breakups explained 20% of limerence in dating relationships among the participants (F=8.03, p<.001). Therefore, as a strategy to solve the problems related to limerence during the period of dating, cognitive and educational interventions are needed to strengthen the self-esteem and sexual autonomy of college students who have had a high number of separations. In addition, early screening of college students with risk factors for limerence and providing problem-solving based counseling will help improve their psychological health.

OJT Characteristics and OJT Outcomes in a Domestic Travel Industry: Moderating Effect of Tie Strength (OJT 특성요인과 OJT 성과 간 관계에서 훈련자-피훈련자 관계강도 조절효과 분석: 국내 여행서비스업 초기 경력자를 대상으로)

  • Park, Chan-Joo;Chang, Ji-Hyun
    • Journal of Distribution Science
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    • v.14 no.5
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    • pp.39-50
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    • 2016
  • Purpose - The purpose of this study was to substantiate the relationship between on-the-job training (OJT) characteristic factors and OJT outcomes and the moderating effect of the tie strength between a trainer and a trainee on the relationship. OJT characteristic factors were composed of a unit of work to be learned, trainee's motivation, trainer's ability, OJT design, and OJT support. OJT outcomes included job satisfaction and organizational commitment in the research. The tie strength means a sense of intimacy with a trainer. All of the OJT characteristic factors, OJT outcomes, and the tie strength were defined operationally as the perceived ones by a trainee. Research design, data, and methodology - This study analyzed the data of 302 employees in a domestic travel agency as early career for seven years or less. The main methods for the analysis were multiple linear regression analysis and moderating effect analysis. The whole process of the data analysis was conducted using the SPSS 21.0 for windows. Results - The results of the study are as follows: First, every five element of OJT, including unit of work to be learned, trainee's motivation, trainer's ability, OJT design, and OJT support, showed positive influence on OJT outcomes - job satisfaction and organizational commitment. Second, the tie strength between a trainer and a trainee was positively related with OJT outcomes. Finally, the strength of ties between the trainer and the trainee was found positively to moderate the relationship of a unit of work to be learned, OJT design, or OJT support, with OJT outcomes. However, the moderating effect of the tie strength was not significant statistically between the trainee's motivation or the trainer's ability, and OJT outcomes. Conclusion - In the study, it was demonstrated that every OJT characteristic factors have a positive contribution to job satisfaction and organizational commitment for early career employees. In addition, the study showed the need to pay attention to improve the quality of relationships between trainers and trainees, in order to increase the impact of a unit of work to be learned, OJT design, and OJT support. These findings suggest the implications in the three factors as external factors that constitute OJT. The three factors are made by HRD practitioners who are involved in design and operation of the program as well as their interventions to improve the quality of the relationship between trainers and trainees. On the other hand, it was demonstrated in the research that trainee's motivation and trainer's ability, regardless of their tie strength, have a direct impact on OJT outcomes by itself. Moreover, the trainee's motivation and trainer's ability are intrinsic characteristics, rather than external factors that constitute OJT. Therefore, they are unlikely to be changed by HRD practitioners' interventions. In conclusion, it was argued in the research that the trainee's motivation and trainer's ability should be a consideration in selecting and matching partners in OJT participants before starting OJT.

Association between Low Density Lipoprotein Cholesterol and Pulmonary Function among Premenopausal women in their 40s: a Retrospective Cohort study (40대 폐경 전 여성에서 저밀도 지단백 콜레스테롤과 폐 기능의 연관성: 후향적 코호트 연구)

  • Ko, Hae-Jin;Youn, Chang-Ho;Kim, Seong-Hyun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.11
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    • pp.6694-6701
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    • 2014
  • The aim of this study was to identify the correlation between low density lipoprotein (LDL) cholesterol and the pulmonary function. This study enrolled premenopausal women in their aged 40s, who visited the health promotion center of a general hospital more than two times. A total of 384 subjects were classified into four groups based on their LDL-cholesterol levels; A, LDL(mg/dL)<100 at both initial and follow-up; B, LDL<100 at initial but ${\geq}100$ at follow-up; C, $LDL{\geq}100$ at initial but <100 on follow-up; and D, $LDL{\geq}100$ at both the initial and follow-up test. The result showed no significant differences in the pulmonary function between the four groups. Multiple linear regression analysis, which was adjusted for age, body mass index, smoking, exercise, and follow-up duration, showed a significant negative relationship between the changes in the LDL and the changes in the $FEV_1/FVC$ (${\beta}=-0.109$, S.E.=0.029, P<0.001), but not in the $FEV_1$ and FVC. In conclusion, there was a significant but weak relationship between the LDL and pulmonary function. Further larger studies will be needed.

Relationship between Eating Attitude in Female Adolescent and Psychological, Biological Factors ; Depression, Aggression, Impulsiveness and Blood Cholesterol Level (여고생 식이태도와 심리적 및 생리적 요인과의 상관관계 ; 우울감, 공격성, 충동성 및 혈중 콜레스테롤에 대하여)

  • Park, June-Sung;Lee, Joon-Seok;Lee, Jang-Han;Yang, Byung-Hwan;Cho, Yun-Gyoo
    • Korean Journal of Psychosomatic Medicine
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    • v.9 no.2
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    • pp.182-193
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    • 2001
  • The purpose of this study is to evaluate correlation of adolescent eating attitude and psychological factors which might influence the eating attitude such as depression, aggression and impulsiveness. The author also tried to identify relationship between adolescent eating attitude and biological factors such as serum cholesterol level and triglyceride level. Two hundred and forty one female high school students without physical disorder were selected as study subjects. For the study, Eating Attitude Test-26KA (EAT -26KA), Beck Depression Inventory (BDI) -Korean version, Barrat Impulsiveness scale (BIS) -Korean version, and Buss-DurKee Hostility Inventory (BDHI) -Korean version were used. Serum cholesterol level and triglyceride level were also investigated. For the purpose of identifying factors which could influence eating attitude of adolescence, stepwise multiple linear regression analysis was done. Total score of BDHI could be most significant factor to explain eating attitude, and BDI, serum cholesterol/triglyceride level be second, third position respectively. But, BIS was not significant predicting parameter. The contributing portion of these factors to explain eating behavior was 25.9%.

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