• Journal of the Korea institute for structural maintenance and inspection
• /
• v.20 no.3
• /
• pp.10-17
• /
• 2016

This paper presents a laboratory validation of a new approach for Finite Element Model Updating(FEMU) on short-span bridges by combining ambient vibration measurements with static load input-deflection output measurements. The conventional FEMU approach based on modal parameters requires the assumption on the system mass matrix for the eigen-value analysis. The proposed approach doesn't require the assumption and even provides a way to update the mass matrix. The proposed approach consists of two steps: 1) updating the stiffness matrix using the static input-deflection output measurements, and 2) updating the mass matrix using a few lower natural frequencies. For a validation of the proposed approach, Young's modulus of the laboratory model was updated by the proposed approach and compared with the value obtained from strain-stress tests in a Universal Testing Machine. Result of the conventional FEMU was also compared with the result of the proposed approach. It was found that proposed approach successfully estimated the Young's modulus and the mass density reasonably while the conventional FEMU showed a large error when used with higher-modes. In addition, the FE modeling error was discussed.

• Environmental and Resource Economics Review
• /
• v.19 no.1
• /
• pp.101-127
• /
• 2010

The purpose of the research is to tackle proximity effects (PEs) when nonmarket valuation method CVM is applied to environmental goods such as tidal flats. 1,000 households are surveyed in the ratio of national household for the research. The sample are reclassified into five areas by 30-minute distance. Log-linear are used to analysis PEs in the research. On conclusion log-linear model regarding income effects proves that PEs are apparently represented in NMVMs(${\theta}_1$ >0. ${\theta}_2$ >0 and $dum1{\neq}0$, $dum2{\neq}0$, $dum3{\neq}0$, $dum4{\neq}0$) as a result of a 5 per cent significant level of t -test and F-test, finally rejecting the null hypothesis. In addition, WTP of area I respondents shows 26 per cent more then that of area V respondents, which is from \87,969 to \64,866 in the open-ended format. Finally, the research proves that the PEs in CVM are evidently represented with the econometric model, hence the PEs have to be embedded into the questionnaire of non-market valuation methods with the environmental goods to reduce the underestimation and improve the estimation accuracy.

• Korean Journal of Community Nutrition
• /
• v.6 no.4
• /
• pp.604-616
• /
• 2001

This study was to investigate weight-control experience disorder and nutrient intake of college student attending web class via the internet. The subject were 1200 college students(392 male, 808 female) attending web class concerned with nutrition and weight control. This cross-sectional survey was conducted by self-administered questionnaire and data were analyzed by Students t-test and $\chi$$^2$-test. Nutrient intake collected from 3 day-recalls were analyzed by the Computer Aided Nutritional Analysis Program. Mean height, weight and RBW(relative body weight) of the male college students were 174.7 cm, 68.0 kg and 101.2%, respectively. Mean height, weight and RBW of the female college students were 162.3% cm, 52.7% kg and 95.3% respectively. Among the male college students, low weight were 1.0%, underweight were 12.8%, overweight were 12.5%, obese were 6.9% by RBW standard. Among the female college students, low weight were 5.1%, underweight 30.2%, overweight were 5.2%, obese were 1.5% by RBW standard. Percentages of weight control experience were 21.7% and 67.0% in the male and female college students, respectively. According to RBW, 22.4% of the weight control experience group were low weight or underweight in the female college students but none of weight control experience group were low weight or underweight in the male college students. Percentage of eating disorder were 6.8%(2.8%, male, 8.7% female) in the college students. Among the female college students, most nutrient intakes were significantly lower in the weight-control experienced group compared to the weight-control nonexperienced group. Among the male college students, there was a tendency that the intake of nutrients, except carbohydrate, calcium and vitamin A was higher in the eating disorder group compared to the non-eating disorder group. However, among the female college students, there was a tendency that the intake of nutrients, except calcium and thiamin was lower in the eating disorder group compared to the non-eating disorder group. Therefore, nutrition education via the internet is required for college students to know proper weight loss methods, desirable eating habits and eating disorder problem well.

• Journal of Distribution Science
• /
• v.14 no.6
• /
• pp.75-80
• /
• 2016

Purpose - A growing demand for sustainability reporting has placed pressure on firms with non-financial information that affects firm valuation, growth, and development. In particular, a number of researchers have investigated various topics in Corporate Social Responsibility (CSR), non-financial information. Prior studies suggest that CSR may affect corporate outcomes like corporate reporting, financial performance, and disclosures. However, the results from prior studies are not clear whether CSR affects corporate outcomes. This is partially due to the measurement issues with CSR. In this study, we examine whether CSR affects the quality of corporate reporting, one of the popular measures in corporate outcomes. We find an evidence that CSR positively affects the quality of corporate reporting. Research design, data, and methodology - In this study, we collected a unique dataset of CSR from MSCI. Total 169 firms listed in the Korean Stock Exchange from 2011 to 2014 were collected and analysed with the detailed CSR reports. Using a correlation test, we found a weak association between CSR and the quality of corporate reporting. However, the regression tests provided a strong relationship between CSR and the quality of corporate reporting after controlling for other variables that may affect the quality of corporate reporting. Additionally, we calculated the t-statistics based on heteroskedaticity-consistent standard errors (White, 1980). Results - Before we run the regression test, we sort the measures of the two dependent variables into each rating of CSR (from AAA to CCC). The results indicate that the quality of corporate reporting measured by discretionary accruals and performance-matched discretionary accruals monotonically decrease as the CSR ratings increase. This supports our hypothesis. In the regression tests, the coefficient on MJDA (PMDA) is -0.183 (-0.173) and significant at the 5% level. We can interpret the results as CSR affecting the quality of corporate reporting in positive ways. Other coefficients on control variables are consistent with prior studies. For example, the coefficients on both LOSS and LEV are positive and significant at conventional level, meaning that firms with financial difficulty may harm their quality of corporate reporting. Conclusion - We found an evidence that CSR is positively associated with the quality of corporate reporting. This study contributes to the literature in various ways. First, this study extends the line of CSR research by providing additional evidence in the setting of ethical behaviors by managements. This is consistent with the hypothesis and supports the results of prior studies. Second, to the best of my knowledge, this is the first study using the MSCI CSR ratings. In contrast with prior studies using different measures of CSR, the MSCI CSR ratings allow us to provide in-depth analysis. Third, the additional measure of dependent variable (PMDA) allows us to improve the robustness of our results. Overall, the results provided this study to extend the findings in prior studies by providing incremental evidence.

• Journal of Korean Foot and Ankle Society
• /
• v.15 no.2
• /
• pp.62-67
• /
• 2011

Purpose: The authors evaluated the differences between K-wires and Cannulated screw, plate for fixing the proximal metatarsal chevron osteotomy of moderate and severe hallux valgus. Materials and Methods: There were 62 patients (79 feetz) who were moderate and severe degree hallux valgus according to the classification of Mann. They all got the proximal chevron osteotomy when correcting the deformity. We divided the patients into 4 groups, Two K-wire fixed group as A, one cannulated screw fixed group as B. Two cannulated screw fixed group as C, Plate fixed group as D, Group A were patients (26 feet) and Group B were patients z(9 feet), Group C were patients (31 feet) and Group D were patients (13 feet). Preoperative, postoperative and follow-up hallux valgus angle (HVA) and intermetatarsal angle (IMA) were measured for each patient. ANOVA test and Student t-test were done for statistical analysis. Results: Mean follow up period was 43.8 months (range: 12~82 months). Preoperative mean IMA was $16.4{\pm}3.5$, $17.7{\pm}11.3$, $17.3{\pm}5.9$ and $16.6{\pm}2.3$ degrees in respectively group A, B, C, D. Immediate postoperative mean IMA was $5.6{\pm}3.4$, $7.3{\pm}4.4$, $7.6{\pm}4.4$ and $6.7{\pm}2.8$ degrees in respectively group A, B, C, D. The final mean IMA was $8.9{\pm}4.5$, $15.2{\pm}7.5$, $10.3{\pm}4.4$ and D $7.7{\pm}3.5$ degrees in respectively group A, B, C, D. There were significant statistical increase in final mean IMA of group B and C (p<0.05). Conclusion: The IMA was significantly increased in the group which used one or two cannulated screw for fixation on follow up, therefore more caution should be needed when using one or two cannulated screw fixation technique after proximal chevron osteotomy.

• Journal of Korean Physical Therapy Science
• /
• v.12 no.3
• /
• pp.47-58
• /
• 2005

The purpose of this study is to estimate how much the motility of affected and unaffected lower limb respectively would have effects on their ambulation through comparing the difference between their affected and unaffected lower limb and studying the correlation between such difference and their ambulation. In addition, the study also intends to find out remedial measures suitable for improving their ambulation with relevant physical treatment. To do this, a quantitative electromyogram(QEMG) test was done to both quadriceps and hamstring of affected and unaffected lower limb so as to yield IP values. Based on such IP values, RMS(root mean square) values as the total sum of IP values were found with QEMG analysis system (made by Medelec Co.) and then the ambulation depending on the difference in muscular strength were analyzed by ink-foot print method as well as the corresponding statistics were processed by T-test through SPSS. The effect of differences in muscular strength of quadriceps in affected and unaffected limb of hemiplegic patients on their ambulation was also different in each element of ambulation. However, there was not any statistically significant difference (p>.05). The differences in muscular strength of hamstring in unaffected limbs of hemiplegic patients only affect stride length. It was statistically significant. The effect of difference in muscular strength of the hamstring in affected limb of hemiplegic patients on their ambulation was very different between strong and weak group in terms of walking velocity, step per minute, stride and step length, showing statistically significant difference(p<.05). Although there was a difference in the step length of the affected limb, it was not statistically significant(p>.05). For the unaffected hamstring, there were significant differences of stride length between in unaffected limb and in affected limb. For the affected hamstring, there were also significant differences in walking velocity, step per minute, stride and step length. Besides, it was found that the difference of the muscular strength between strong and weak group was at the highest. Thus, the effect of difference in muscular strength on ambulatory factors such as walking velocity, step per minute, stride and step length did not show any statistical significance but differences in affected and unaffected quadriceps. However, it was found that both the difference of stride in unaffected hamstring and the difference of all ambulatory factors except from step length with affected limb had effects on ambulation depending upon muscular strength.

• Journal of the Korean Society of Earth Science Education
• /
• v.9 no.3
• /
• pp.341-351
• /
• 2016

The purpose of this study is to investigate the effects of pre-service teachers of elementary school who take courses in 'Science and Textbook Research' on science teaching efficacy and science knowledge after experimental treatment. For this purpose, this study was aimed at intensive course four classes (118 students) enrolled in the 'Science and Textbook Research' course and experimented from the beginning of September to the end of November. The experiment was about teaching textbooks and teaching methods for one semester, and the pre- service teachers of elementary school made the demonstration of science cooperation classes by group. The results and analysis of the study were analyzed by the corresponding sample test in before and after the group test. The conclusion of the study is as follows. First, after taking this class the pre - service teachers of elementary school were effective in science teaching efficacy. Second, after taking this course, pre-service teachers of elementary school were effective in acquiring science knowledge. Third, it was seemed to positive effect on Perception of pre-service teachers of elementary school in Demonstration classes. Pre-service teachers of elementary school have created science course plan by analyzing the tasks according to the principles of instructional design, and they found that they had the right mind and confidence in the lesson.

• Journal of Korean society of Dental Hygiene
• /
• v.15 no.1
• /
• pp.81-89
• /
• 2015

Objectives: The purpose of the study is to investigate the effect of values on major satisfaction in dental hygiene students. Methods: The subjects were 214 dental hygiene students in Seoul and Gyeonggi-do who filled out the self-reported questionnaire after receiving informed consents from January 20 to February 15, 2014. Except incomplete answers, 187 data were analyzed using PASW Statistics 18.0 for Scheffe post hoc test, Pearson correlation coefficient, hierarchical regression analysis, independent sample t-test, and one-way ANOVA. The questionnaire consisted of general characteristics of the subjects and values. General characteristics consisted of gender, age, grade, school record, major choice motivation, and the influencing person to choose the major. The instrument for values was modified from Shin based on MILOV(Multi-Item Measures Of Values) and two professors of dental hygiene verified the validity of the instrument. Instrument for values consisted of 7 questions of values for self-respect, 6 questions of relation oriented values, 5 questions of emotion oriented values, and 5 questions of values for others measured by Likert 5 scale. Cronbach's alpha was 0.769 in the study. The instrument for major satisfaction was modified from Na based on Program Evaluation Survey of Illinois University and two professors of dental hygiene verified the validity of the instrument. Major satisfaction consisted of 7 questions of general satisfaction, 5 questions of consciousness satisfaction, 5 questions of curriculum satisfaction and 3 questions of relation satisfaction measured by Likert 5 scale and Cronbach's alpha was 0.887 in the study. Results: Values of self-respect, relationship orientation and grade had significant influence on general satisfaction, while values of self-respect, relationship orientation and gender had significant influence on consciousness satisfaction. Values of relationship orientation, grade and school record had significant influence on curriculum satisfaction. Grade showed significant influence on relationship satisfaction. Conclusions: Values of self-respect and relationship orientation are the most important factors in dental hygiene students. The guidance for professional career and major satisfaction can be accomplished through the values of self-respect and relationship orientation.

• Journal of Korean society of Dental Hygiene
• /
• v.15 no.1
• /
• pp.39-46
• /
• 2015

Objectives: The purpose of the study is to investigate the cognition of dental caries prevention by the level of socioeconomic status based on Gallup survey in Korea. Methods: This study was done by Korean Gallup survey in October, 2010. A trained researcher carried out the computer aided telephone interview(CATI) using a structured questionnaire. This study was based on the latest population statistics of resident registration and whole country's phone data base. This survey included 869 selected Korean adults over 19 years old, and they were asked to answer a CATI. The questionnaire consisted of general characteristics of the subjects and socioeconomic factors including age, gender, education level, monthly income, and residential area. Cognition of dental caries prevention was measured by Likert 4 scale including 'much', 'a little', 'rarely', and 'never'. The attitude toward dental caries prevention consisted of daily tooth brushing frequency, experience of oral health education, regular dental checkup, chewing gums(xylitol), regular scaling, and use of oral care devices. Data were analyzed using SPSS 20.0 for frequency analysis, t-test, chi-square test, and one way ANOVA. Cronbach's alpha was 0.462 in oral health concern and attitude. Results: Mean of the frequencies of daily tooth brushing in men was 2.54 times and 2.78 in women. By the comparison to age group, 35-44 years old group had 2.82 times, 19-37 years old group had 2.72 times, and 45-64 years old group had 2.51 times. The level of education and monthly income was proportional to the tooth brushing frequency. Highly educated and higher monthly income group received regular dental checkup within a year and used the auxiliary oral health care devices. Conclusions: This study suggested the relationship between dental caries prevention and socioeconomic status. It is important to provide the low socioeconomic group with the better oral health promotion services in the future.

• Journal of Science Education
• /
• v.34 no.1
• /
• pp.124-139
• /
• 2010

The purpose of this study was to develop and apply a framework for progression in the professional development and learning of secondary science teachers' teaching practice. The progression in the professional development was modified Pilhee Woo's framework(2010), and in the learning was developed by the researchers. The former included 6 elements and 36 aspects. The progression of each aspect was composed of five level criteria. The content validity is 96.4% and the reliability is .96. The latter was composed of another five level criteria. The content validity is 96.0% and the reliability is .95. Internet-online test and the questionnaire were administered to 203 secondary science teachers who were selected by convenience sampling. The mean level of the progression in the professional development and learning were 2.21 and 2.95. ANOVA, t-test and correlation analysis were conducted to compare differences by the characteristics of teachers. The level of the progression in the professional development and learning was significant difference according to almost all of teachers' characteristics. The level of the progression in the professional development was significantly correlated with the level of the progression in the learning.