• Title/Summary/Keyword: Multiple linear Regression

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Mandibular changes during initial alignment with SmartClip self-ligating and conventional brackets: A single-center prospective randomized controlled clinical trial

  • Celikoglu, Mevlut;Bayram, Mehmet;Nur, Metin;Kilkis, Dogan
    • The korean journal of orthodontics
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    • v.45 no.2
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    • pp.89-94
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    • 2015
  • Objective: To test the null hypothesis that SmartClip self-ligating brackets are more effective than conventional brackets for initial mandibular alignment and identify influential factors. Methods: Fifty patients were randomly allocated to two equal treatment groups by using an online randomization program: self-ligating group (SmartClip brackets) and conventional group (Gemini brackets). The archwire sequence was standardized. Changes in anterior irregularity index, intercanine width, and intermolar width were assessed on plaster models at 8th and 16th weeks. Changes in incisor position and inclination were assessed on lateral cephalometric radiographs at 16 weeks. Intragroup and intergroup comparisons were performed with paired t-test and Student's t-test, respectively. Multiple linear regression was performed to identify variables affecting improvement in anterior ambiguity. Results: Data of 46 patients were analyzed; those missing an appointment (n = 2) or showing bracket breakage (n = 2) were excluded. Incisor inclination (p < 0.05), intercanine width (p < 0.05), and intermolar width (p > 0.05) increased at 8 and 16 weeks in both the groups; no significant intergroup differences were noted (p > 0.05). Initial anterior irregularity index and intercanine width change were significantly associated with improvement in anterior irregularity (p < 0.001). Conclusions: The null hypothesis was rejected. Bracket type has little effect on improvement in anterior ambiguity during initial mandibular alignment.

Obesity-related behaviors of Malaysian adolescents: a sample from Kajang district of Selangor state

  • Rezali, Fara Wahida;Chin, Yit Siew;Yusof, Barakatun Nisak Mohd
    • Nutrition Research and Practice
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    • v.6 no.5
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    • pp.458-465
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    • 2012
  • This study aims to determine the association between obesity-related behaviors (dietary practices, physical activity and body image) and body weight status among adolescents. A total of 382 adolescents (187 males and 195 females) aged 13 to 15 years in Kajang, Selangor participated in this study. Majority of the respondents were Malays (56.0%), followed by Chinese (30.1%) and Indians (13.9%). Dietary practices, physical activity and body image of the adolescents were assessed through the eating behaviors questionnaire, two-day dietary record, two-day physical activity record and multi-dimensional body image scale (MBIS), respectively. Body weight and height were measured by trained researchers. The prevalence of overweight and obesity (19.5%) was about twice the prevalence of underweight (10.5%). About two-thirds of the respondents (72.3%) skipped at least one meal and half of them (56.2%) snacked between meals with a mean energy intake of $1,641{\pm}452$ kcal/day. More than half of the respondents (56.8%) were practicing sedentary lifestyle with a mean energy expenditure of $1,631{\pm}573$ kcal per day. Energy intake (r = 0.153, P < 0.05), physical activity (r = 0.463, P < 0.01) and body image (r = 0.424, P < 0.01) were correlated with BMI. However, meal skipping, snacking and energy expenditure per kg body weight were not associated with body weight status. Multiple linear regression analysis showed that body image, physical activity and energy intake contributed significantly in explaining body weight status of the adolescents. In short, overweight and obesity were likely to be associated not only with energy intake and physical activity, but also body image. Hence, promoting healthy eating, active lifestyle and positive body image should be incorporated in future obesity prevention programmes in adolescents.

Serum immunoglobulin E (IgE) levels and dietary intake of Korean infants and young children with atopic dermatitis

  • Lee, Sangeun;Ahn, Kangmo;Paik, Hee Young;Chung, Sang-Jin
    • Nutrition Research and Practice
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    • v.6 no.5
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    • pp.429-435
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    • 2012
  • Atopic dermatitis (AD) has become a serious epidemic in Korean children. We aimed to investigate the association between vitamin C, E and other nutrients, and serum total IgE/specific IgE levels in children with AD. A total of 119 children (0-24 mo) diagnosed with AD were recruited for this cross-sectional study from a medical center in Seoul. A 24 h recall was used to assess dietary intakes. Serum total and six food-allergen specific IgE levels were measured by CAP-FEIA. Serum vitamin E was also measured but only in 25 out of the total 119 participants. Multiple linear regression analysis was performed to estimate the coefficients between serum IgE levels and dietary intake as well as serum vitamin E. Serum vitamin E levels showed a significantly inverse association with serum total IgE and all specific IgE levels (P < 0.05). Fat intake was inversely related with specific-IgEs for egg whites, milk, buck wheat, soy, and peanuts (P < 0.05). Positive associations were found between carbohydrate (CHO) intake and total IgE and specific IgEs to egg whites, milk, soy, and peanuts (P < 0.05). Vitamin C, E and n-3/n-6 fatty acids were not related with serum total IgE and specific IgE levels except for the association between buck wheat and vitamin E. In addition, there were no significant differences between males and females in dietary intake and serum IgE levels by student's t-test. Although dietary vitamin E showed no association with serum IgE levels, serum vitamin E drew a significant inverse relationship with serum IgE levels. The evidence seems to suggest that vitamin E may possibly lower total and specific-IgEs in children with AD, and that it is important to maintain a relatively high serum vitamin E level in children with AD.

An Estimation of Discharge Coefficient Considering the Geometrical Shape of Broad Crested Side Weir (광정횡월류위어의 기하학적 형상을 고려한 유량계수 산정)

  • Cho, Hong-Je;Kang, Ho-Seon
    • Journal of Korea Water Resources Association
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    • v.44 no.12
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    • pp.955-965
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    • 2011
  • The flow characteristics of rectangular and 1 : 1 and 1 : 2 trapezoidal weirs were investigated through hydraulic experiments in order calculate the exact overflow discharge of the broad-crested side weir. The flow was found to be most stable in trapezoidal shapes with the lowest incline. The 1 : 1 and 1 : 2 trapezoidal weirs had 5.67% and 8.57% increases, respectively, compared to the rectangular weir in terms of overflow amount, which suggests that they are more effective in preventing flood. An integrated discharge coefficient equation taking into account the discharge coefficient equation and shapes was proposed through a multiple linear regression analysis with an addition of a new parameter for the side wear, $L/L_H$, to the conventional discharge coefficient equation. Also, the applicability of the newly proposed discharge coefficient equation was reviewed by comparing the measured and calculated overflow amounts based on the experimental data of preceding researches and existing researchers and the research data of this study.

Factors Affecting User´s Satisfaction in Development of Natural Recreation Forest (자휴양림의 개발요소가 이용만족도에 미치는 영향)

  • 장병문
    • Journal of the Korean Institute of Landscape Architecture
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    • v.29 no.3
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    • pp.19-28
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    • 2001
  • The purpose of this paper is to examine factors affecting user´s satisfaction in development of natural recreation forest(NRF) in order to answer the research question: What is the magnitude of factors affecting user´s satisfaction in development of NRF. After reviewing the literature, mechanism of outdoor recreation, and development factors in NRF, we constructed the conceptual framework and have formulated the hypothesis of this research. we have obtained data through a questionnaire, which surveyed 625 visitors at 10 of the 72 natural recreation forests in Korea in 1999, We have analyzed the data using the mean difference test, Pearson´s correlation analysis, and multiple linear regression method. We found that 1) all the development factors except recreational resources affecting user´s satisfaction have turned out to be statistically significant at one percent level. The direction of relationship between independent variable and dependent variable is the same as that of dependent variable. 2) in bivariate analysis, the relationships between user´s satisfaction and all the development factors are fairly high and statistically significant. The higher the value of development factors, the higher the degree of user´s satisfaction. 3 in multivariate analysis, such variables as the suitability of activities level of services, atmosphere, and facility have been statistically significant at one percent level, and 4) Their relative contribution of the suitability of various recreational activities, level of atmosphere, and service on dependent variable have been turned out to have 8.167, 4.889, 3.333, and 1.611 times more importance than that of the suitabity of recreational resources, respectively. The research results suggest that a guideline for the creation of marketable NFR and development of use-programs and recreational atmosphere be recommended in the planning and development process of NRF, and excessive investment on facilities is not desirable. The approach and analysis method adopted by this research is highly useful for an evaluation criterion of NRF and development of devices for increasing user´s satisfaction in NRF. It is recommended that more empirical study on individual factors affecting user´s satisfaction be performed in the future.

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Research on the Characteristics of Skin Color of Age 25-35 Females of Korea, China, and Vietnam (한국, 중국, 베트남 25~35세 여성의 피부색 특성 연구)

  • Ahn, Cheunsoon;Kim, Su Hwan;Kim, Chanju
    • Journal of the Korean Society of Clothing and Textiles
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    • v.41 no.3
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    • pp.501-516
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    • 2017
  • Skin colors of females between the ages of 25-35 from Korea, China, and Vietnam were measured in Seoul, Beijing, and Hanoi using the Minolta CM-600d spectrophotometer. CIE Lab and Munsell HVC data of the face (forehead and both cheeks) and body (neck and arm) were analyzed using t-test, Analysis of Variance (ANOVA), Duncan's Multiple Range Test, Linear Regression Analysis, and K-Means Cluster Analysis using SPSS software. Korean females showed the highest L and V values for the face and body; Vietnamese females showed the highest b value in the face and the highest a value in the body. Higher L and b values for the face were related to higher L and b values of the body; this relationship was more prominent in Korean females. The younger age group (25-29) showed higher L values and lower b values than the older age group (30-35). Females from Korea, China, and Vietnam were grouped into Type 1 and Type 2 based on skin color. Type 1 had darker skin with more redness and yellowness and Type 2 had lighter skin with less redness and yellowness. A total of 88.2% of Korean females belonged to Type 2, 80.4% of Vietnamese females were Type 1, and Chinese females indicated an even distribution of Type 1 and Type 2.

Oral health status of long-term care facility residents (노인요양시설 거주자의 구강건강상태)

  • Choi, Jun-Seon
    • Journal of Korean society of Dental Hygiene
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    • v.17 no.3
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    • pp.527-537
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    • 2017
  • Objectives: The purpose of this study was to examine the practice of oral hygiene behaviors and oral health status of long-term care facility residents and to analyze the factors related to salivary hemoglobin level which can predict active periodontal disease. Methods: From 30th October 2015 to 7th January 2016, a questionnaire was provided to 63 participants and their dental plaque and saliva samples were collected to assess the levels of salivary hemoglobin and dental plaque acidogenicity. In order to analyze the factors related to salivary hemoglobin level, multiple linear regression analysis was performed. Results: Toothbrushing was most frequently performed by the participants themselves (98.4%) and toothbrushing was performed after eating breakfast (81.3%). 68.8% of participants reported brushing their tongue. 35.9% of participants perceived having bad teeth, and 87.5% had high dental caries activity. The percentages of participants with hyposalivation and ${\geq}0.20{\mu}g/ml$ salivary hemoglobin level were 45.3% and 59.4%, respectively. The salivary hemoglobin level was significantly higher in the group in which stimulated salivary flow rate was ${\leq}0.70ml/min$, dental plaque acidogenicity was superior, and perceived having bad teeth (p<0.05). There was also a tendency for the salivary hemoglobin level to increase with age (p<0.05). Conclusions: Oral health status of the long-term care facility residents was still not improved, and the characteristics of salivary volume and dental plaque were important factors affecting salivary hemoglobin level. Therefore, it is necessary to operate an oral hygiene intervention program by oral health professionals in such facilities in order to provide residents with effective oral care aligned with their respective needs. Furthermore, it is necessary for caregivers to complete mandatory oral health education to improve the oral hygiene status of the long-term care facility residents.

The Relationship between Treating, after Treated of Osteoarthritis, Osteoporosis and Quality of Life in Korean Adults: Based on the 2010 Korean Community Health Survey

  • Jegal, Hyuk;Jun, Hyun Ju;Kim, Ki Jong
    • Journal of International Academy of Physical Therapy Research
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    • v.6 no.1
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    • pp.828-832
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    • 2015
  • The purpose of this study was to investigate the relationship the quality of life, osteoarthritis and osteoporosis in the Republic of Korea. This study was utilized raw data from the 2010 KCHS. In total, 229,229 individuals participated in the 2010 survey. The final analysis was identified 22,545 individuals who had been diagnosed by a doctor with arthritis or osteoporosis. To identify the relationship between the quality of life - related after treated or treating of arthritis, osteoporosis, A multiple linear regression analysis was performed. Treating group for osteoarthritis of their quality of life has statistically been less than after treated group(B=-.068, p<.001). Treating group for osteoporosis of their quality of life has statistically been less than after treated group(B=-.083, p<.001). Non-treatment group who was diagnosed by doctor, but no treated subject for osteoarthritis of their quality of life has statistically been less than after treated group(B=-.075, p<.001). Non-treatment group that was diagnosed by doctor, but no treated subject for osteoporosis of their quality of life has statistically been less than after treated group(B=-.045, p<.001). Non-treatment group who was diagnosed by doctor, but no treated subject for osteoporosis and arthritis of their quality of life has statistically been less than after treated group(B=-.0121, p<.001). as a result of those data, we understand that the decision maker for treatment has been chosen by quality of life, including pain, mobility activity and so on.

Analysis of Bird Species Diversity Response to Structural Conditions of Urban Park - Focused on 26 Urban Parks in Cheonan City - (도시공원 구조 및 식생 조건에 따른 조류 종다양성 분석 - 천안시 26개 도시공원을 대상으로 -)

  • Song, Wonkyong
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.18 no.3
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    • pp.65-77
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    • 2015
  • The urban park has important functions as a habitat for wildlife as well as open space of rest and community for people. This study was carried out to find what factors of structure and vegetation of urban parks could affect forest bird species diversity in Cheonan city. The study surveyed bird and vegetation species in 26 urban parks, Cheonan city. A correlation analysis and multiple linear regressions were performed to test whether habitat structure and vegetation were the major correlate with species diversity. The results showed the Dujeong park was the most high bird species diversity (H' = 2.13), and the Dujeong-8 park (H' = 2.02) and the Cheongsa park (H' = 1.73) were considerably higher than the other urban parks. The variables that were strongly correlated with bird species diversity were park area, number of subtree species, canopy of shrub, number of shrub species, shape index, canopy of subtree, canopy of tree, and impervious surface ratio. The regression of bird species diversity against the environmental variables showed that 3 variables of park area, canopy of subtree, and canopy of tree were included in the best model. Model variable selection was broadly similar for the 5 optimal models. It means park area and multi-layer vegetation were the most consistent and significant predictor of bird species diversity, because urban parks were isolated by built-up areas. Especially the subtree coverage that provides shelter and food for forest birds was an important variable. Therefore, to make parks circular-shaped and abundant multi-layer vegetation, which could be a buffer to external disturbances and improve the quality of habitats, may be used to enhance species diversity in creation and management of urban parks.

Identification of Printer Noise Source and Its Sound Quality Evaluation System Development (프린터 부품 소음원에 따른 감성소음 평가시스템의 개발)

  • Park, Sang-Won;Yang, Hong-Jun;Na, Eun-Woo;Lee, Sang-Kwon;Park, Yeong-Jae;Kim, Jong-Woo
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.20 no.11
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    • pp.1018-1024
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    • 2010
  • The printer noise consists of the noise of the various components and parts such as motor, fan and solenoid. And the human's printing sound recognition shows various aspects when the printer starts to print papers because the components operate at the same time. Especially, printers are usually installed in the quiet office room. Therefore the printing noise is related to its competitiveness in the market. The importance of the printer sound qualities is increasing and it is necessary to develop the sound quality evaluation system, so it is a key point to identify the noise source of the printer and develop the sound quality index to each component. By using this evaluation system, it is possible to evaluate the sound quality of a prototype printer compared to the already existing one. In this paper, the printer sound quality evaluation system was developed by the following steps. Firstly, the signal processing method was applied to the recorded printing sound to identity and split the noise of components. Secondly, the MLR(multiple linear regression) method and the psychoacoustics were used to develop the sound quality index. Finally, the improvement of the printer sound quality is possible by using the result of the MLR and the path analysis. The output of this research will be applied to the development of a new printer.