• International Journal of Highway Engineering
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• v.14 no.5
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• pp.189-199
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• 2012

PURPOSES: The purpose of this study is to propose a new methodology for developing statistical collision models and to show the validation results of the methodology. METHODS: A new modeling method of introducing variables into the model one by one in a multiplicative form is suggested. A method for choosing explanatory variables to be introduced into the model is explained. A method for determining functional forms for each explanatory variable is introduced as well as a parameter estimating procedure. A model selection method is also dealt with. Finally, the validation results is provided to demonstrate the efficacy of the final models developed using the method suggested in this study. RESULTS: According to the results of the validation for the total and injury collisions, the predictive powers of the models developed using the method suggested in this study were better than those of generalized linear models for the same data. CONCLUSIONS: Using the methodology suggested in this study, we could develop better statistical collision models having better predictive powers. This was because the methodology enabled us to find the relationships between dependant variable and each explanatory variable individually and to find the functional forms for the relationships which can be more likely non-linear.

• Journal of Elementary Mathematics Education in Korea
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• v.21 no.1
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• pp.49-72
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• 2017

Despite the importance and necessity of functional thinking in a primary school there has been lack of research in this area, specifically regarding young children. Given this, this study analyzed how students aged from 7 to 9 would figure out and represent the co-variational relationships in context-driven tasks. Semi-clinical interviews were conducted with a total of 12 students. Interview tasks included three types of functions: (a) y=x, (b) y=x+1, and (c) y=x+x. The results of this study showed that most students were able to figure out co-variational relationships in diverse ways. Some factors such as types of function or characteristics of tasks had an impact on how students recognized the relationships. The students also could represent the relationship in diverse ways such as gesture, picture, natural language, and variables. They usually used natural language, but had a trouble using variables when representing the relation between co-varying quantities. Based on these results, this study provides implications on how to foster functional thinking ability at the elementary school.

• Journal of the Korean Society of Physical Medicine
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• v.15 no.2
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• pp.109-120
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• 2020

PURPOSE: This study was conducted to verify the effects of a functional correction of the pain of patients with chronic low back pain(CLBP), and to examine the effect of dysfunctional factors on health-related quality of life. METHODS: A preliminary survey was first conducted on 90 patients with CLBP after functional orthodontic treatment. Some revised questionnaires were also prepared. The survey was distributed for approximately eight weeks, and 215 copies were used as the final analysis data, except for questionnaires that were inadequate, error or non-response. RESULTS: Path analysis using the structural equation model of CLBP patients showed a positive correlation between all the path coefficients and the potential factors. The multidimensional relationship between pain and dysfunction after orthognathic treatment was confirmed using three subdivisions of the pain variables as independent variables and the dysfunctional variables as the dependent variables. Multiple regression analysis was performed to examine the effects of pain on the dysfunction. To identify the multidimensional relationship between dysfunction and the health-related quality of life, eight sub-factors of dysfunctional variables were set as the independent variables, and multiple regression was analyses were performed with the dependent variables of the health-related quality of life. CONCLUSION: This study examined the structural and influence relationships of the functional correction with pain, dysfunction, and health-related quality of life. The results, suggest that a functional orthodontic treatment can be used as a positive program for the health-related quality of life. In addition, this study is meaningful in that it provieds useful information for intervention such as psychosocial change of patients.

• Journal of the Ergonomics Society of Korea
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• v.20 no.1
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• pp.87-113
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• 2001

This study introduces the concept of image/impression of a product design, human interface elements, and the relationships between them. It is assumed that the human interface can be decomposed into detailed design elements, called human interface elements. This study attempts to build functional relationships between the image/impression of a product and human interface elements. Two different human factors experiments were conducted to demonstrate the effectiveness of the approach suggested in this study. A total of 35 audio/visual consumer electronics products (e.g., CD players, VCRs) were shown on a display screen and the subjects were instructed to evaluate them in terms of eight image/impression dimensions. One experiment was conducted using Korean subjects while the other using American subjects. The functional relationships were modeled by using the multiple linear regression technique. Similarity and difference between the Korean and the American subjects were analyzed. The approach suggested in this study is expected to help designers and developers identify important design variables to enhance the subjective satisfaction of a product design.

• 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.

• The Research Journal of the Costume Culture
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• v.12 no.4
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• pp.614-627
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• 2004

The objectives of this study were to investigate the relationships between self-concept and cosmetic benefits sought, to disclose the differences in the benefits according to demographic variables and cosmetic purchase behavior, and to examine how cosmetic benefits were influenced by self-concept and demographic variables of women. Subjects were 453 women in age from 18 to 55 years in Seoul. Four dimensions of cosmetic benefits of women were derived by factor analysis :＇brand orientation＇, ＇fashion＇, ＇economies＇, and ＇functional efficiency＇, Cosmetic benefit was influenced most by family self-concept, and self-concept was influenced most by benefit of economics, next by functional efficiency, and fashion. Brand orientation, fashion, and economics showed significant differences according to marital status. The higher the income, the higher the score on brand orientation, fashion, and functional efficiency. There were significant differences in brand orientation, fashion, and economics according to cosmetic purchase expense, the number of purchase times, and stores, while functional efficiency showed no significant difference depending upon the number of cosmetic purchase times. Brand orientation was influenced by marital status, income, and physical self, fashion influenced by age(-), physical self, income, and family self(-). Economics was influenced by family self(-) and marital status(-). The present findings provided that self-concept such as physical self and family self is significant variables to understand the cosmetic benefits sought.

• The Mathematical Education
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• v.50 no.2
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• pp.213-231
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• 2011

The purpose of this study is to analyze the 6th graders' understanding of the concepts of variable on various aspects of school algebra. For this purpose, the test of concepts of variable targeting a sixth-grade class was conducted and then two students were selected for in-depth interview. The level of mathematics achievement of the two students was not significantly different but there were differences between them in terms of understanding about the concepts of variable. The results obtained in this study are as follows: First, the students had little basic understanding of the variables and they had many cognitive difficulties with respect to the variables. Second, the students were familiar with only the symbol '${\Box}$' not the other letters nor symbols. Third, students comprehended the variable as generalizers imperfectly. Fourth, the students' skill of operations between letters was below expectations and there was the student who omitted the mathematical sign in letter expressions including the mathematical sign such as x+3. Fifth, the students lacked the ability to reason the patterns inductively and symbolize them using variables. Sixth, in connection with the variables in functional relationships, the students were more familiar with the potential and discrete variation than practical and continuous variation. On the basis of the results, this study gives several implications related to the early algebra education, especially the teaching methods of variables.

• Korean Journal of Community Nutrition
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• v.3 no.5
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• pp.707-714
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• 1998

This cross-sectional study was designed to describe in nutritional and health status of the Korean elderly residing in America using demographic variables, dietary, anthropometric and functional status indicators, and to investigate possible relationships among these variables. Sixty elderly persons aged 61-91 years were assessed in their homes. Dietary intake was estimated by the 24-hour recall and brief dietary questionnaire. The following anthropometric measures were taken : weight, height, knee height, triceps skinfold, and midarm circumference. Functional status was measured by activities of daily living(ADLs), instrumental activities of daily living(IADLs) questionnaires, and a measure of psychosocial status as "happiness score"(a life satisfaction questionnaire). Intakes of energy, calcium, magnesium, folacin, vitamin B6, and zinc were low in this elderly sample. Females 75 years of age and older had extremely low energy intakes. A large percentage of subjects reported difficulty with both activities of daily living and instrumental activities of daily living. Subjects over 75 years of age reported more difficulty than younger subjects for most activities. Gender differnces were seen in anthropometric variables and energy intake. Happiness scores were similar in subjects, regardless of age or gender, however, happiness score was significantly correlated with the energy and protein intake(p<0.05). Several difficulties were encountered during the assessment of this elderly sample. The conditions in the home were unpredictable and often inadequate for the anthropometric measures in particular. Further research is needed to improve current methodologies so that they may be more adaptable to the conditions found in homes. in homes.

• East Asian Journal of Business Economics (EAJBE)
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• v.8 no.1
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• pp.57-69
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• 2020

Purpose - This study examines what are the asset market fluctuations in Europe and how each economic variable affects major variables, and explore the dynamics of housing and stock market through Greece. The variables under consideration are balance on current account (BCA), index of stock (STOCK), gross domestic product (GDP), housing price indices (HOUSING), M3, real rate of interest (IR_REAL) and household credits (LOAN). We investigate the functional and causal relationships between housing and stock market. Research design, data, and methodology - Vector error correction model (VECM) is used to figure out the dynamic relationships among variables. This study also contains the augmented Dickey-Fuller unit root, cointegration, Granger causality test, and impulse response function and variance decomposition analysis by EViews 11.0. Results - The statistical tests show that all variables under consideration have one unit root and there is a longterm equilibrium relationship among variables for Greece. GDP, IR_REAL, M3, STOCK and LOAN can be considered as causal factors to affect real estate market, while GDP, LOAN, M3, BCA and HOUSING can bring direct effects to stock market in Greece. Conclusions - It can be judged that the policy that affects the lending policy of financial institutions may be more effective than the indirect variable such as monetary interest rate.

• Journal of muscle and joint health
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• v.20 no.3
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• pp.225-234
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• 2013

Purpose: This purpose of study was to investigate the relationships among functional state, self-efficacy, and life satisfaction in the elderly with decreased visual acuity. Methods: The subjects were 162 elderly people from the G university hospital. Functional state was measured by Late-Life Function and Disability Instrument (LLFDI) and Minimum Data Set-Home Care version 2.0 (MDS HC 2.0). Self-efficacy and Life satisfaction were measured by the tool of Rho & Lee (2011) and Yoon (2007). Data were analyzed using t-test, ANOVA, Pearson's Correlation Coefficient, and logistic regression. Results: The daily life function was significantly associated with self-efficacy and vision decrease. The regression model with these two variables explained 35.6% of the variance of daily life function. IADL was significantly associated with vision decrease, age, gender, and self-efficacy. The regression model with the three variables explained 52.9% of the variance of IADL. Life satisfaction is significantly associated with self-efficacy, daily life function, vision decrease and IADL. The last regression model with the four variables explained 51.8% of the variance of life satisfaction. Conclusion: The levels of functional state, self-efficacy and life satisfaction in the elderly with decreased visual acuity were low. Self-efficacy was an important factor that influences on the functional state and life satisfaction. Therefore, nursing interventions that can enhance the self-efficacy are required in order to increase the functional state and life satisfaction in the elderly with decreased visual acuity.