• Korean Chemical Engineering Research
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• v.53 no.4
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• pp.440-444
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• 2015

Effects of operating variables on the solid circulation rate were investigated in a three-phase circulating fluidized bed, of which inside diameter was 0.102m and height was 3.5m, respectively. Gas velocity, primary and secondary liquid velocities, particle size and height of solid particles piled up in the solid recycle device were chosen as operating variables. The solid circulation rate increased with increasing primary and secondary liquid velocities and height of solid particles piled up in the solid recycle device, but decreased with increasing particle size. The value of solid circulation rate decreased only slightly with increasing gas velocity in the riser. The values of solid circulation rate were well correlated in terms of dimensionless groups within the experimental conditions.

• Journal of Community Nutrition
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• v.7 no.4
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• pp.184-192
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• 2005

This study is to investigate the concerns about obesity and diet behaviors among 565 middle and high school students in Ulsan. The results indicated that high school students rather than middle school students and girls rather than boys had higher concerns about obesity and diet behaviors. For the socio-economic variables, being female, a high school student, and a group with the least monthly allowance was higher concern about obesity and diet; and household income, educational level and occupation of the fathers also had significant impacts on the student concerns about obesity and diet behaviors. The variables of height, weight, PIBW (Percentage of Ideal Body Weight), and BMI (Body Mass Index) had significant impacts on the concerns about obesity and diet behaviors. Especially, students with normal weight had the highest concerns about obesity and diet, while obese students had the lowest concerns. (J Community Nutrition 7(4): $184\∼192$, 2005)

• Korean Journal of Human Ecology
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• v.16 no.5
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• pp.1041-1050
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• 2007

The purpose of this study was to investigate the variables which had effects on deit behavior of male and female high school students. The proposed variables are their body-related variables(body satisfaction, weight control experience, the degree of diet interest, and obesity) and self-esteem. The sample group used for the study consisted of 359 high school students(male=168, female=191). Measurement scales used for the study were those of body-related variables, self esteem and eating disorder behavior, and data analysis was performed using $X^2$, t-test, Pearson's correlation, regression analysis. The results are as follows. First, there is a significant difference between male and female high school students regarding their obesity perceived by themselves, body satisfaction, the degree of diet interest, weight control experience, and deit behavior. Second, In male students, diet behavior shows a positive correlation with the degree of diet interest, weight control experience, and body satisfaction, but shows a negative correlation with body satisfaction. In female students, diet behavior is positively correlated with the degree of diet interest, weight control experience, and obesity, but negatively correlated with body satisfaction and self-esteem. Third, in male students, the variables that showed a influence on diet behavior as an eating disorder are weight control experience, body satisfaction and obesity, in that the explanatory power of the variables is 51.7% with the highest mark on obesity. In female, the variables that showed a influence on diet behavior as an eating disorder are the degree of diet interest, weight control experience, body satisfaction and obesity, in that the explanatory power of the variables is 66.0%.

• Journal of the Korean Institute of Landscape Architecture
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• v.13 no.2
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• pp.37-70
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• 1985

The purpose of this study is to present objective basic data for environmental design by the quantitative analysis of visual quality emboded in physical environment. For this, as for the front garden of high schools, the spatial image was measured by the S.D. Scale Method, Factor Analysis was proceeded by the principal component analysis and the visual preference was investigated by the Paired Comparision Method. The scale values of plain and unpleasant road surface and external appearance of buildings, which are related to emotions of simpleness fell from straightness and stability, were found to be high. But, except for the road surface of Kyunggi High School, scale values of variables explaining the variation of the quality of materials, level of floor and rythm were generally low. For all green spaces, scale values of variables explaining the degree of pleasantness was found to be generally high. And, those explaining tidiness and characteristics of green spaces were not in the same tendency. But, the green spaces of Youngdong High school can be considered to the space with plenty of visual absorption uniqueness were high. As for the correlation between variables, variables for green spaces(12 and 26) and those for overall view of front garden( 1 and 4) revealed high positive correlation. Also, "order - disorder" and "convenient- incovenient" included in road surface variable can be regarded to have the same meaning since the correlation coefficient between them is very high, 0.7045. Image variables including road surface, external appearance of buildings, green spaces and overall view of front garden showed 91.21~61.08% of total variance. Thus, the remains can be considered to be the error valiance or specific variance. In Fctor I, II and III, main components explaining the road surface image of front gardens are order, hardness, texture, color, gradient and rythm. As for the external appearance of b wilding, variables of color, hardness, stability, peculiality and shape revealed high values of factor load. For all variables, communality was drastically high and ellen values and common variance were found to be very high in Factor I. As for the front gardens, variables explaining volume and peculiarity were found to be the main components of Factor I. In Factor II and III, variables of factor load were tidiness, pleasantness.

• Communications of Mathematical Education
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• v.37 no.3
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• pp.419-442
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• 2023

This study investigated fifth graders' understanding of variables from a generalized arithmetic and a functional perspectives of early algebra. Specifically, regarding a generalized perspective, we included the property of 1, the commutative property of addition, the associative property of multiplication, and a problem context with indeterminate quantities. Regarding the functional perspective, we covered additive, multiplicative, squaring, and linear relationships. A total of 246 students from 11 schools participated in this study. The results showed that most students could find specific values for variables and understood that equations involving variables could be rewritten using different symbols. However, they struggled to generalize problem situations involving indeterminate quantities to equations with variables. They also tended to think that variables used in representing the property of 1 and the commutative property of addition could only be natural numbers, and about 25% of the students thought that variables were fixed to a single number. Based on these findings, this paper suggests implications for elementary school students' understanding and teaching of variables.

• Journal of Families and Better Life
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• v.9 no.1 s.17
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• pp.13-26
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• 1991

The purpose of the study is to examine the realities of the high school students's aggressive behavior, and to analyze factors causing aggressive behavior. Subjects were 418 Humanity High School students of 2nd grades in pusan. Analysis methods were used to frequency, percentage, t-test, one way ANOVA, Pearson's correlation, and multiple regression of SPSS program. The results are as follows ; 1) Male students are more aggressive than female students. 2) The more verbal aggression is the more physical aggression. 3) Students with the experience of parent-child violence are more aggressive. 4) Students with observation of parents's violence are more aggressive. 5) Family's social economic status is not related to the aggressive behavior. 6) Male students not admitted by teacher are more aggressive in verbal and physical behavior. 7) Female students not admitted by friend are more aggressive in verbal and physical behavior. 8) Students with deliquent friends are more aggressive in verbal and physical behavior. 9) Students with Academic anxiety are more aggressive in verbal behavior. 10) the variables influential to verbal aggressive behavior are sex, a delinquent friends and academic anaxiety. These factors explain 23.5% of the total variance of verbal aggressive behavior variables. The variables influential to physical aggressive behavior are a delinquent friends, sex, experience of parent-child violence and teacher's denial attitude. These factors explain 29.6% of the total variance for physical aggressive behavior variables.

• The Korean Journal of Community Living Science
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• v.19 no.4
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• pp.641-658
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• 2008

The purpose of this study was to analyze the effects of parent-child communication, and the self-efficacy of middle school students on school adjustment. The data was collected from 285 middle school students living in Kwangju. For statistical analysis, Cronbach' $\alpha$, t-test, one-way ANOVA, Scheffe's multiple Comparison Analysis, LSD and hierarchical regression analysis were used. The results were summarized as follows : concerning connections between demographic variables and parent-child communication, the education of the father made the most significant difference, followed by living standard, free time for communication with the father, and free time for communication with the mother. The level of communication with parent made a significant difference to each sub-factor of school adjustment. As a result of making a hierarchical regression analysis to find out the relative impact of the demographic variables on school adjustment, self-efficacy was identified as the most important variable and predictor of school adjustment. The independent variables exercised a different influence on the sub-factors of school adjustment. These results indicated that adolescent's self-efficacy is the most important variable to improve the school adjustment of students.

• Human Ecology Research
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• v.53 no.4
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• pp.425-432
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• 2015

This paper verifies the effect of the personal dietary habits on students' school lunch satisfaction and the effect of food related activities such as rural communities' experience and safe and nutrition education. Personal dietary habits (5-Likert scale), satisfaction of school lunch (5-Likert scale), and rural community experiences, are investigated. A survey from 10 middle schools in Gyeonggi-do was undertaken from September to October, 2014. Multi regression analysis and t -test are applied. This study applied factor analysis and derived three latent variables in order to know the latent variables of eating habits. Students with rural communities' experience are satisfied with school lunches more than those who have not experienced it. Further related education (such as eating habits, safe and organic food) have a positive effect on students' school lunch satisfaction. Appreciation for school lunch (p<.001) and eating breakfast (p<.01) are significant among the independent variables that included three latent variables, the taste of school lunch (p<.001), eating well all kinds of food (p <.001). The results shows that students with a balanced diet are more satisfied with school lunches. Personal eating habits and understanding food and agriculture are important factors to improve students' satisfaction about school lunch on top of the quality of food and facilities. Students with rural community experience show improved satisfaction and this experience can be a good way for students to understand food. Food related education (including farming) are recommended to raise student school lunch satisfaction.

• Journal of Korean Society for Quality Management
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• v.39 no.2
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• pp.244-255
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• 2011

In this study, we try to evaluate the efficiency of the photonics industry using a data envelopment analysis(DEA) model. We first develope four stage procedures for selecting proper input and output variables which consist of selecting the first candidate variables from literature survey, selecting the second candidate variables through experts' discussion, measuring the partial efficiency of the selected variables based on Tofallis' profiling, and clustering some variables through the rank correlation analysis of partial efficiency proposed by Min and Kim(l998). With this procedure, we select 4 input variables(capital, number of employee, R&D cost, operating cost) and 2 output variables(sales, growth of sales) and then utilize CCR and BCC model to measure efficiencies of 26 photonics companies in Gwangju. Moreover, we perform the reference group analysis to figure out what causes inefficiencies and to provide the desirable values for input and output variables at which inefficient photonics companies become efficient. Finally, we classify 26 photonics companies into three groups such as optical communications, optical applications, and optical sources, and perform the Kruskal-Wallis test to check if there exist some differences between efficiencies of three groups.

• Journal of the Korean Mathematical Society
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• v.52 no.2
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• pp.431-445
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• 2015

Extensions of the Kolmogorov convergence criterion and the Marcinkiewicz-Zygmund inequalities from independent random variables to conditional independent ones are derived. As their applications, a conditional version of the Marcinkiewicz-Zygmund strong law of large numbers and a result on convergence in $L^p$ for conditionally independent and conditionally identically distributed random variables are established, respectively.