• Journal of dental hygiene science
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• v.17 no.4
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• pp.315-322
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• 2017

The aim of this study was to explore the association between daily toothbrushing frequency and health risk behaviors of school-going adolescents in poor urban areas of Peru. A cross-sectional survey was conducted among 959 school-going adolescents 11~19 years of age in poor urban areas of Peru in 2014. Health risk behaviors we assessed in the study were smoking; drinking; consuming sugar-sweetened soft drinks (more than one cup); leisure time activities including watching television, playing games, and using the Internet; and never or rarely handwashing with soap. Daily toothbrushing frequency was divided into two groups (once and twice daily). For statistical analyses, the chi-square test and hierarchical logistic regression were used at 5% level of significance. Of the total respondents, 63 (14.3%) were boys and 53 (10.3%) were girls and 116 (12.1%) engaged in toothbrushing (${\leq}1$ times daily). According to the adjusted logistic regression analysis for socio-demographic characteristics, two behaviors (leisure time use activities, including watching television, playing games, and using the Internet (odds ratio [OR], 2.29; 95% confidence interval [CI], 1.20~4.35), and never or rarely hand washing with soap (OR, 4.09; CI, 2.48~6.75) were statistically associated with toothbrushing frequency (${\leq}1$ times daily). We found two health risk behaviors (leisure time activities, including watching television, playing games, and using the Internet, and never or rarely handwashing with soap) associated with toothbrushing frequency among adolescents in the study area. Thus, oral health promotion programs should consider these health risk behaviors associated with toothbrushing frequency.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.35 no.3
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• pp.625-637
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• 2015

This study aims to calculate optimal travel speeds based on analysis of the AVI data collected in the uninterrupted traffic flow, and the results are as follows. Firstly, we looked into the distribution of the sectional travel times of each probe vehicle and compared the difference in the sectional travel speeds of each probe vehicle. As a result, it is shown that outliers should be removed for the distribution of the sectional travel times. Secondly, there were differences among type 1(passenger automobiles) & type 2(automobiles for passengers and freight) and type 4(special automobiles) in the non-congestion section. thus it was revealed that there is a necessity to remove type 4(special automobiles) when calculating the sectional travel speeds. Thirdly, Based on the results of these, the optimal outlier removal procedures were applied to this study. As a result, it showed that the MAPE was between 0.3% and 2.0% and RMSE was between 0.3 and 2.3 which are very similar figures to the actual average traffic speed. Also, the minimum sample size was satisfied at the confidence level of 95%. The result of study is expected to serve as a useful basis for the local government to build the AVI. In the future, it will be necessary to study to integrate AVI data and other data for more accurate traffic information.

• Journal of Korean Society of Transportation
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• v.20 no.6
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• pp.115-128
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• 2002

Traffic engineers have developed and implemented various microscopic simulation models to verify the traffic performance and to prevent the expected problems. The existing microscopic simulation models categorize drivers into several types to reflect various drivers' driving patterns but miss the dynamics of drivers' behavior changed based upon the traffic conditions. It was found from the field data collected from two different merging sections on an urban freeway in Seoul, Korea, that the drivers' critical gap distributions are changed based on (1) the traffic density on the adjacent lane to the acceleration lane and (2) the opportunities left to merge in terms of distance to the end of acceleration lane. It was also found from the study that the drivers' critical gap distributions follow the Normal distribution. and its mean and variance change while a vehicle progresses on an acceleration lane. This paper proposes a new gap-acceptance model developed based on a set of drivers' critical gap distributions from each segment on the acceleration lanes. Through the comparison study between the field data and the results from the simulation utilizing the proposed model, it was verified that (1) the distribution of merging points on an acceleration lane to the adjacent main lane at different density levels, (2) the size of the gap accepted for merging and (3) the speed difference between the merging vehicle and the trailing vehicle at the time of merging are statistically identical to the field data at 95% confidence level.

• The Korean Journal of Food And Nutrition
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• v.31 no.3
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• pp.425-434
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• 2018

Metabolic syndrome is a risk factor for cardiovascular and type 2 diabetes. This study was conducted to examine the relevance between nutrition intake, meal quality, and high-sensitivity C-reactive protein in Koreans with metabolic syndrome. The 2,536 subjects, aged 19~64, who participated in 2015 National Nutrition Survey were included in this study. The 24-hour recall method was employed to analyze nutrition intake and dietary quality. Subjects were grouped into either the non-metabolic syndrome group (n=1,938) or the metabolic syndrome group (n=598). Total males and females were divided into 3 groups according to the high-sensitivity C-reactive protein (hs-CRP) level to study its relationship to metabolic syndrome and its components, including odds ratio (OR) and confidence interval (CI). Results showed the homeostasis model assessment of insulin resistance (HOMA-IR) value was higher in the metabolic syndrome group (3.37) than non-metabolic syndrome group (1.57) (p<0.001). In the Index of Nutrition Quality, males in the non-metabolic syndrome group showed higher niacin (p<0.05) than males in metabolic syndrome group. Females in the non-metabolic syndrome group had higher vitamin $B_1$ (p<0.01), vitamin $B_2$ (p<0.001), niacin (p<0.05), calcium (p<0.001), and phosphate (p<0.01). Female in the high hs-CRP group showed high OR in blood glucose component (OR 2.488, 95% CI: 1.269~4.879) and metabolic syndrome risk (OR 2.856, 95% CI: 1.292~6.314). Females in the middle hs-CRP group had high triglycerides component (OR 2.956, 95% CI: 1.920~4.551), compared to the low hs-CRP group. The study showed females with higher hs-CRP had a higher risk of metabolic syndrome.

• Fire Science and Engineering
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• v.33 no.4
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• pp.35-40
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• 2019

In this study, the mass flow rate of the heat release rate equation, which is the major factor of the oxygen consumption method, was analyzed for the fundamental investigation of the cone-calorimeter (5 m length and 0.3 m diameter). The shapes of a completely empty inside, 3 mm pore diameter mesh and pore diameter 10 mm honeycomb with 0.76 porosity were constructed using the cone-calorimeter. To calculate the mass flow rate, four bi-directional probes and thermocouples were installed in a uniform position in the vertical direction of flow. The velocity gradient and flow perturbation were measured from the increase in Reynolds number. As the flow capacity increased, the speed gradient increased in all three shapes relative to the turbulence intensity. In addition, the deviation of extended uncertainty to the mass flow was completely low in the order of empty space, mesh (d_p = 3 mm) and honeycomb (d_p = 10 mm and 𝜖 = 0.76) at the 95% confidence level. The results can be used in designs to improve the flow stability of the cone calorimeter.

• Journal of The Korean Association For Science Education
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• v.41 no.4
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• pp.283-295
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• 2021

This study attempts to explore the nature of science anxiety experienced by science-gifted middle school students based on Giorgi's phenomenological research method. Among the first-year middle school students selected by the University-affiliated Science Education Institute for the Gifted, six science-gifted students with high levels of science trait anxiety and science state anxiety experience were selected. Two interviews related to experience of science anxiety were conducted with participants. As a result of the analysis, science anxiety experienced by science-gifted students was caused by setting the ideal self-concept, lack of confidence, past experiences, difficulty in contents, and something valuable. Students complained of physical·physiological, cognitive, emotional·psychological discomfort when they felt science anxiety, and recognized it as an opportunity for growth. In addition, science-gifted students were shown to cope with various ways such as confronting uneasy situations directly or refining their minds to overcome various uncomfortable symptoms that arise when science anxiety is triggered. Some students thought that no special efforts were required to lower their level of anxiety because anxiety was relieved over time. The students had both negative and positive meanings for science anxiety. The results of this study will help teachers in-depth understanding of middle school science-gifted students who experience science anxiety and provide a theoretical basis for what kind of educational environment should be created and educational programs should be provided in relation to science anxiety.

• Korean Journal of Legislative Studies
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• v.24 no.1
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• pp.135-170
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• 2018

The recent success of populist parties and candidates in the US and European countries leads to a massive amount of empirical research on populism, a deviant form of representative democracy. Much ink has been spilled to define populism and to identify the causes of its rise and continued success in democratic political system. However, little is known about populist attitudes of individual voters. Using a large-scale online survey fielded in the context of the South Korean presidential election in 2017, this study examines (1) what determines populist attitudes of South Korean voters and (2) how populist attitudes are associated with evaluations of political parties, candidates, and political issues. Statistical analysis reveals that people high on populism are more likely to support an underdog left-wing political party and its presidential candidate, and are less likely to support policies implemented or proposed under the auspices of the Park Geun-hye administration. These findings do not necessarily suggest the inherent affinity between populism and left-wing ideology; rather, it implies populist attitudes happened to appear in 2017, in reactions to lack of confidence in the previous government.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.6D
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• pp.697-705
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• 2010

The purpose of this research is to clarify the relation between environmental consciousness and railway usage behavior. Author would locate this research on position of basic survey to promote railway use according to Low Carbon Green Growth policy in Korea. In this research, we would perform descriptive analysis using data of research on the actual condition of railway use in 2008, Daegu, and describe its relationship. In addition, we would suggest some idea about policy which can promote railway use. The order of railway choice behavior noticed in clustering of environmental consciousness was cooperative behavior type, middle type and non-cooperative behavior type. It suggests that environmental consciousness has effect on transportation choice behavior. Specially, railway improvement isn't enough to promote railway use. And, it is advisable to carry out the improvement in such a way that it may encourage the nation to move from the current environmental consciousness stage to cooperative behavior. Moreover, we assumed Binary Probit(BP) model using SP data of time or condition of transportation expense compared with passenger car and bus. As the results, modified likelihood ratio of two BP models is favorable variables. And it occurred that mode was transferred from passenger car to railway when it showed higher social environment consciousness and low selfish environment consciousness, because t-statistic which represents selfish environment consciousness showed significance in 95% confidence level. That is, it can be described that environment consciousness affect on the intention of railway use.

• Journal of The Korean Association For Science Education
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• v.27 no.9
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• pp.881-892
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• 2007

This study is aimed to classify teachers' questions and feedbacks as well as students' responses in term, of type and frequency, and speculate the distinctive features of verbal interactions including teachers' questions and feedbacks performed actively in the classes of the gifted in science. The 24 hours of the classes made for the 8th grade science-gifted students were observed and recorded. In addition, the mutual conversations between the teacher and the students were transcribed and analyzed, and the interviews with the teachers also were made. It is found that the teachers usually use the question methods of memory recollection, perception and memorization, together with an instant feedback method, while the students prefer to respond with rather short answers. The characteristic features of the class by the teachers who lead the active class show that they use the open questions at the beginning, raise the level of the questioning, use the questions 'why and how' frequently, and to ask evaluative questions. Their feedbacks to the students interestingly indicate that they show the students the attitude of accepting and receiving students' replies, invite different responses from other students by reserving instant answers or judgements to the students, and give the students the confidence of solving the next problems, by praising and encouraging them.

• Journal of the Korean Society for Marine Environment & Energy
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• v.20 no.1
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• pp.55-61
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• 2017

This study conducted a survey to evaluate the disaster response capability of coastal residents and analyzed the characteristics. For the sampling process, nonrandom sampling method was used. Sample size is 4,520 and sample error is ${\pm}1.5%p$ at 95% confidence level. As a result of the survey, 72% and 68% of the respondents said that they recognized the emergency contact network and listened to the disaster broadcast. On the other hand, 17% and 18% said that they organized the local voluntary disaster prevention teams and participated in disaster preparedness training. In addition, male's disaster response capability was higher than female's, and first aid techniques and participation in disaster preparedness training were higher in teens and twenties. By occupation, public official possess the highest response capability. By region, it was high in the East coast and low in the South coast. It is necessary that the authorities improve the national disaster preparedness training and publicity to enhance the coastal disaster response capability of coastal residents.