• Transactions of the Korean Society of Machine Tool Engineers
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• v.13 no.1
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• pp.88-93
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• 2004

In general, a fundamental structural design consideration for an automobile is the overall dynamic behavior in bending and torsion. Dynamic behavior of the automobile are mainly influenced by the structural stiffness of B.I.W.(body-in-white) and the physical property of trim components. In this paper, the modeling techniques for various trim components of middle-sized bus are presented, and the dynamic effects of the trim components on the vibration characteristics of the bus are investigated. The $1^{st}$ torsional frequency is decreased by attaching windshield and backlite to the B.I.W., but the $1^{st}$ vertical bending frequency and the $1^{st}$ lateral bending frequency are increased. The natural frequencies of the bus are decreased by attaching doors and windows. And also, the natural frequencies of the bus are large decreased by attaching seats, instrument panel etc. The study shows that the dynamic characteristics of the bus can be effectively predicted in the initial design stage.

• Earthquakes and Structures
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• v.6 no.3
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• pp.251-266
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• 2014

Dynamic analyses for a suite of ground of motions were conducted on concrete gravity dam sections to examine the earthquake induced stresses and effective damping. For this purpose, frequency domain methods that rigorously incorporate dam-reservoir-foundation interaction and time domain methods with approximate hydrodynamic foundation interaction effects were employed. The maximum principal tensile stresses and their distribution at the dam base, which are important parameters for concrete dam design, were obtained using the frequency domain approach. Prediction equations were proposed for these stresses and their distribution at the dam base. Comparisons of the stress results obtained using frequency and time domain methods revealed that the dam height and ratio of modulus of elasticity of foundation rock to concrete are significant parameters that may influence earthquake induced stresses. A new effective damping prediction equation was proposed in order to estimate earthquake stresses accurately with the approximate time domain approach.

• The Korean Journal of Food And Nutrition
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• v.27 no.6
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• pp.1163-1174
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• 2014

The purposes of this study were to investigate the eating of breakfast by female middle school students in Seoul, the perception of the school breakfast program (SBP), and determine the factors affecting the intention to participate in SBP. Out of 340 questionnaires distributed to the female middle school students, 334 were returned (98.2% response rate) and 323 were analyzed. The subjects were categorized into two groups by the intention to participate in SBP. Subjects were classified as participating and non participating groups. As a result of analyzing the breakfast intake frequency, 'hardly eat' showed the highest with 18.5% in the participating group and 10.3% in non participating group, while 'eat every day' showed 38.2% in the participating group, and the highest with 65.5% in non participating group (p<0.001). For the reason for skipping breakfast, 'no time' showed the highest with 30.0% in the participating group, 'over sleep' and 'no appetite' showed the highest with 24.8% in non participating group. For the reason for not participating in SBP, 'breakfast should be eaten at home' showed the highest with 47.2% in non participating group and 'may get up early in the morning' showed the highest with 46.2% in participating group (p<0.01). To determine the factors affecting the intention to participate in SBP, logistic regression analyses were conducted for female middle school students. According to the logistic regression analysis, father's education level was independently associated with the intention to participate in SBP in female middle school students [Odds Ratios (OR) 2.38, 95% Confidence Interval (CI) 1.03~5.52]. Frequency of eating breakfast on weekdays (OR 1.36, 95% CI 1.01~1.81), Level of need for school breakfast (OR 0.52, 95% CI 0.35~0.76) and whether to approve school breakfast (OR 0.27, 95% CI 0.18~0.41) were independently associated with the intention to participate in SBP in female middle school students. In conclusion, proper educational efforts for importance of school breakfast could be useful plan to develop school breakfast program.

• Journal of the East Asian Society of Dietary Life
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• v.17 no.5
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• pp.615-625
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• 2007

This study investigated the overall conditions related to family meals, including perceptions, attitudes, and behaviors, among middle and high school students. The data were collected from 773 male and female students attending middle and high schools in Seoul and Kyunggi-Do from March to May 2006, using pre-tested self-administered questionnaires. The results are as follows: 78.9% of the subjects lived with their parents and siblings, and 75.7% regarded family meals as meals eaten with all family members living together in a household. As for the frequency of family meals, 40.1% of the middle school subjects answered that they ate with their family 'more than once per day' and 20.8% answered '1 or 2 time per a week'. However 21.0% of the high school students had family meals 'more than once per day', and 31.7% had family meals '1 or 2 times per a week', showing a significant difference between the groups(p<0.001). When the degree of satisfaction with life was evaluated using a Likert scale(strongly satisfied 5 point, strongly unsatisfied 1 point), the middle school students showed a significantly higher level of satisfaction than the high school students towards daily life, health, nutritive conditions, and family care. feelings, attitudes, and behaviors toward family meals were also evaluated(strongly agree 5 point, strongly disagree 1 point), and the results showed that the subjects had positive psychological feelings, with significant differences based on the frequency of family meals. Likewise, the groups who ate frequent family meals scored higher on aspects related to having positive attitudes and behaviors toward the family meal, implying that eating family meals is associated with promoting friendship, psychological stability, and positive thinking in adolescents. These findings suggest that attention needs to he directed toward increasing the frequency of family meals and creating a positive family meal environment.

• The Korean Journal of Food And Nutrition
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• v.27 no.3
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• pp.369-382
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• 2014

The aim of this study is to provide the fundamental information on satisfaction for school food service and dietary habits of middle school students in Sejong Special Self-Governing City. Generally, the subjects had a high satisfaction level for school food service. The boys had comparatively more satisfactory days for school food service than the girls. The most dissatisfactory factors of school food service were the taste and variety of menu for the girls, and the time and place for lunch and the service of employee for the boys. The intersexual differences existed with a significant difference in the irregular intake of meals, the reasons to skip meals, and the eating speed. For the boys, the main reason to skip meals was due to lack of appetite, and for the girls, it was the weight-control. The boys finished each meal within 5~10 min and ate more than the amount the girls eat in general. The main components of breakfast for the subjects were a cooked rice, soup, and side dish in 65.9%, and the frequency of skipping breakfast was high with 32.8%, which was once per week. The favorite snacks for the middle school students were cookies and beverages in 29.4%, instant foods in 24.3%, and hamburger and pizza in 21.4%. The intake frequency of snacks was once or twice per week in 46.5% of the subjects. In addition, the subjects had a very high intake frequency of fastfoods with once or twice per week in 72.7%, and the most favorite fastfood was ramen in 57.7%. The subjects in 45.3% took dairy food every day. In conclusion, the middle school students need nutrition education to improve their eating habit and to increase the frequency of breakfast.

• Journal of Korean Public Health Nursing
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• v.29 no.1
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• pp.79-89
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• 2015

Purpose: The aim of the study was to determine the effects of a community based participatory program in obese middle-aged women. Methods: One-group pretest-posttest design was used. The subjects were 35 middle-aged women. Data were collected at public health centers in Chungcheongnam-Do from March to May, 2013. To evaluate the effect of the program, physiological indexes(body mass index, skeletal muscle mass, body fat mass, visceral fat area) and health behavior indexes(dietary practice guidelines score, moderate physical activity, drinking frequency) were measured. Analysis was performed using a Wilcoxon Signed Rank Test. Results: After the program, physiological indexes (BMI, BFM, SMM, VFA) and health behavior indexes (dietary guidelines scores, frequency of physical activity, drinking frequency) were significantly improved. Conclusion: The community based participatory obesity program by public health centers is considered to be effective. Therefore, greater effort is needed for better participatory program development of several health promoting fields, and more research is needed in order to examine a continuous effect.

• Journal of Fisheries and Marine Sciences Education
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• v.17 no.1
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• pp.35-47
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• 2005

The purpose of this study is to investigate various kinds of discipline problems in middle school classrooms, and the differences in severity and frequency of the classroom discipline problems between male and female students' classrooms in middle schools. This study shows that the discipline problems in the middle school classrooms include using a cellular phone, chattering, sleeping, chewing gum, reading comic books, asking useless questions, challenging a teacher, fighting, calling names, skipping class, throwing trash in the classroom, breaking classroom equipment, creating disorder, losing materials, playing with a ball in the classroom, gambling, and so on. Generally, male students recognized the severity of the classroom discipline problems more than the female students. However, it is shown that the frequency of discipline problems in male students' classrooms is higher than that in female students' classrooms. From the results of this study, male students have more active discipline problems (playing with a ball in the classroom, throwing trash in the classroom, coming to class late, gambling, cutting in line, and so on). On the other hand, female students have more passive discipline problems (making a noise by using a cellular phone, asking useless questions, sending messages to a classmate, studying other subjects, scattering, and so on).

• Journal of the Korean Dietetic Association
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• v.8 no.2
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• pp.132-142
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• 2002

The purpose of this study was to verify the dietitian’s job description(2000) for dietitians working at hospitals. The survey was carried out for the frequency, criticality and difficulty of each job description with 4 point scales. The subject was 62 dietitians, who have been working over 3 years at their position. The results are following ; 1. Duties with high frequency and criticality were menu managements, food productions, meal services and self promotions. 2. Duties with middle frequency and high criticality in food service area were purchasing, storage and inventory controls, waste managements, sanitation managements, managing equipments and facility, human resources managements and financial managements. 3. Duties with middle frequency and high criticality in nutrition service area were nutrition assessment (life cycles, certain diseases, specific condition), medical nutritional theraphy and nutrition education. 4. For difficulty, duties related nutrition service had higher points than that of food service.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.3
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• pp.1972-1980
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• 2015

This study's purpose was to analyze the effect of the SmartCare obesity management pilot project, which was conducted between 09 March 2011 and 03 April 2013 in Korea (South). Of 212 subjects who were enrolled in the study, the final analysis was conducted with 147 subjects who completed their weight self-measurements and SmartCare services until the end of a 6-month service period. The self-measurement group for evaluation was classified into 3 groups (Low, Middle, and High) by evenly dividing the monthly average frequency of measurement for 6 months and the evaluation indices were weight, and BMI (Body Mass Index) transmitted from the SmartCare System. The monthly average weight and BMI were decreased more in the High Group than the Middle Group and Low Group (M5: High>Middle>Low), and they are showing statistically significant differences between groups (p< 0.05). In conclusion, analysis of the weight and BMI improvement effect showed a greater improvement effect when the self-measurement frequency level was higher.

• Structural Engineering and Mechanics
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• v.76 no.3
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• pp.293-310
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• 2020

This study derives the differential equations of free vertical bending and torsional vibrations for two- and three-pylon suspension bridges using d'Alembert's principle. The respective algorithms for natural vibration frequency and vibration mode are established through the separation of variables. In the case of the three-pylon suspension bridge, the effect of the along-bridge bending vibration of the middle pylon on the vertical bending vibration of the entire bridge is considered. The impact of torsional vibration of the middle pylon about the vertical axis on the torsional vibration of the entire bridge is also analyzed in detail. The feasibility of the proposed method is verified by two engineering examples. A comparative analysis of the results obtained via the proposed and more intricate finite element methods confirmed the former feasibility. Finally, the middle pylon stiffness effect on the vibration frequency of the three-pylon suspension bridge is discussed. It is found that the vibration frequencies of the first- and third-order vertical bending and torsional modes both increase with the middle pylon stiffness. However, the increase amplitudes of third-order bending and torsional modes are relatively small with the middle pylon stiffness increase. Moreover, the second-order bending and torsional frequencies do not change with the middle pylon stiffness.