• Korean Journal of Community Nutrition
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• v.13 no.1
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• pp.13-23
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• 2008

This study investigated the association between the weight status of middle school students and the various weight-related characteristics including desired weight, weight perception, weight-related practice, physical activity, and overeating behavior. Questionnaires were administered to 473 middle school students (178 boys and 295 girls) in Daejeon. Boys and girls were divided into three groups respectively; (1) underweight (BMI<$5^{th}$ percentile) (2) normal weight ($5^{th}$ percentile$\leq$BMI<$85^{th}$ percentile) (3) overweight (BMI$\leq85^{th}$ percentile). Using BMI calculated from measured height and weight, 14.0% of boys and 6.8% of girls were underweight, and 16.3% of boys and 14.2% of girls were overweight. However, among this sample of students, 38.4% of boys and 13.6% of girls perceived themselves as underweight and 29.4% of boys and 44.9% of girls perceived themselves as overweight. We found that overweight students reported their body weights lower and their heights higher compared to non-overweight students, resulting in an underestimation of BMI. Based on desired BMI, 79.9% of the girls desired to be underweight and 73.0% of the boys desired to be normal weight. Overweight or normal weight students were less satisfied with their body weights than underweight students. Girls had more weight control experience and concern compared to boys. Overweight girls spent longer times in watching TV compared to non-overweight girls (p < 0.001) and had more overeating behaviors (p < 0.05). Overweight students reported that they ate snacks less frequently than non-overweight students, which may be due to their tendency to report less eating. In conclusion, significant gender differences and weight status differences existed in weight perception, weight satisfaction, and weight control experience and concern. Because perception of overweight is likely to lead to unhealthy eating behaviors and weight control, efforts for adolescents to improve accuracy of weight perceptions and to understand the benefits of being healthier are needed.

• Journal of Community Nutrition
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• v.6 no.1
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• pp.48-54
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• 2004

The purpose of this study was to examine the effects of dietary protein and exercise on bone mineral density and bone mineral content of growing male rats. Forty male, Sprague-Dawley rats(age 21 days) were assigned to four groups that underwent 9 weeks of experimental treatment. Animals were assigned to one of two exercise treatments (treadmill running or sedentary). The exercise and nonexercise group were fed a diet containing casein or soy with rich isoflavones (3.4mg/g protein). The exercise group ran on a rodent treadmill(speed of 15m/min for 30min) three days per week during the 9-week study period. All rats were fed an experimental diet and deionized water ad libitum for 9 weeks. Total bone mineral density (BMD), total bone mineral content (BMC), total body calcium, spine BMD and BMC, and femur BMD and BMC were determined by using dual energy x-ray absorptiometry (FIXI-mus, GE Lunar Radiation Cooperation, Madison, WI, USA). The soy diet group appears to have a significantly higher total BMD/weight and total BMC/ weight, spine BMD/weight, spine BMC/weight, femur BMD/weight and femur BMC/weight compared to the casein group in nonexercise and exercise. The exercise group had significantly greater total BMD/weight and BMC/ weight, spine BMD/weight and BMC/weight, femur BMD/weight and BMC/weight compared to the nonexercise group when the protein source was casein. The exercise combined soy group had significantly greater total BMD/weight and BMC/weight, spine BMD/weight and BMC/weight, femur BMD/weight and BMC/weight, compared to the exercise combined casein group. The results indicate that exercise had a positive influence on bone mineral density and bone mineral content and soy significantly affect on bone mineral density and bone mineral content for the 9 weeks experimental period. It can be concluded that exercise combined with a soy diet is most beneficial for acquisition of spine bone mineral density in young growing male rats. This convincing evidence suggests that a change in life style such as increasing exercise and consumption of soy protein is a practical strategy for significantly reducing the incidence of osteoporosis.

• Journal of Korean Academy of Nursing
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• v.27 no.3
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• pp.510-519
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• 1997

The purpose of this study was to determine the effect of regular exercise during dexamethasone injection on the body weight, weight of hindlimb muscles and adrenal gland in Young rats. 80-100g Wistar rats were divided into control, exercise, dexamethasone injection(dexa), and exercise during dexamethasone injection(D+E) group. The dexa group received daily subcutaneous injection of dexamethasone at a dose of 5mg/kg body weight for 10 days. The exercise group ran on a treadmill for 60min /day(20 minutes every 4 hour) at l0m/min and a 10$^{\circ}$ grade. The control group received daily subcutaneous injection of normal saline at a dose of 5mg /kg body weight for 10 days. The D+E group ran on a treadmill for 60min /day (20 minutes every 4 hour) at 10m/min and a 10$^{\circ}$ grade. Body weight of both control and exercise group increased significantly until 10 days, that of both dexa and D+E group decreased significantly, resulting in 79.47 and 78.75% decrease respectively compared to the first day of experiment. Body weight and muscle weight of the soleus, plantaris and gastrocnemius decreased significantly with dexamethasone injection. Relative weight of the plantaris and gastrocnemius of the dexa group decreased significantly compared to that of the control group. Body weight and muscle weight of the gastrocnemius of the exercise group increased significantly, and the muscle weight of the soleus and plantaris tended to increase. The Relative weight of the plantaris was comparable to the control group and that of the soleus and gastrocnemius tended to increase in the exercise group. Body weight and muscle weight of the soleus and plantaris of the D+E group showed a tendency to increase, and muscle weight of the gastrocnemius increased significantly compared to the dexa group. The Relative weight of the soleus and gastrocnemius tended to increase, and that of the plantaris of the D+E group increased significantly compared to the dexa group. Body weight, muscle weight and relative weight of the soleus, plantaris and gastrocnemius of the D+E group did not recover to that of the control group. Adrenal gland weight of the dexa and D+E group tended to increase, and that of the exercise group increased significantly. From these results, it can be suggested that regular exercise during dexamethasone injection might attenuate the decrease of body weight and hindlimb muscle weight induced by the dexamethasone injection.

• International Journal of Human Ecology
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• v.12 no.2
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• pp.13-24
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• 2011

This study compared actual weight with perceived weight, described the prevalence of unhealthy weight control behavior, determined the differences in psychological and personal variables between participants that reported unhealthy weight control behavior and those who did not, and examined the relationship of eating habits to unhealthy weight control behavior for Korean adolescents. The study population consisted of a nationally representative sample of middle and high school students who completed the Fifth Korea Youth Risk Behavior Web-based Survey (KYRBWS): Fifth in 2009. Among the 75,066 participants of KYRBWS, 35,473 (n = 18,851 girls and 16,622 boys) were eligible for a research focused on unhealthy weight control behavior. The results of this research were as follows: First, there were considerable discrepancies (45.1% of girls and 32.8% of boys) between the perceived weight and the actual weight. Second, overall, unhealthy weight control behavior was more prevalent in girls and fasting was the most commonly reported behavior. Third, participants that reported unhealthy weight control behavior scored significantly lower on scaled measures of happiness, health, academic achievement, and economic status; in addition, they scored higher on stress measures. Fourth, girls and boys shared common protective factors of having breakfast and vegetables more often, perceiving their weight as underweight rather than overweight, and having a correct weight conception. Protective factors unique to girls were having lunch and dinner more often. Girls and boys shared common risk factors of the consumption of soda, fast food, instant noodles, and snacks more often, while consumption of fruit more often was a risk factor only for girls. The improvement of protective factors and minimization of risk factors through Home Economics classes (and other classes relevant to health) may mitigate unhealthy weight control behavior of adolescents.

• Child Health Nursing Research
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• v.23 no.2
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• pp.249-257
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• 2017

Purpose: The aim of this study was to assess the body weight perception of adolescents and to investigate the difference between mental health and weight control behavior according to body weight perception. Methods: Study data on 12-18 years old adolescents with normal BMI was obtained from the 6th Korea National Health and Nutrition Examination Survey (2013-2015). Rao-Scott Chi-square test and ANOVA were used for the analysis. Results: The percentage of adolescents with a misperception of body weight was 43.3%, and their subjective health status (p=.013), stress perception (p=.001), and depression (p=.001) were worse than for adolescents who had the correct perception of their body weight. The percentage of adolescents who were trying to lose weight while perceiving their body weight as normal was 36.9%. Body weight control behavior had significant differences according to dietary intake (frequency of eating dinner (p=.015)), energy intake (p=.004), and carbohydrate intake (p<.001), but there was no significant difference according to exercise. Conclusion: Parents, school teachers, and nurses should make efforts to ensure that Korean adolescents perceive their body weight correctly, and prevent unhealthy weight control behaviors.

• International Journal of Aeronautical and Space Sciences
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• v.15 no.4
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• pp.383-395
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• 2014

According to the requirement of wing weight estimation and frequent adjustments during aircraft conceptual design, a wing weight estimation method considering the constraints of structural strength and stiffness is proposed to help designers make wing weight estimations rapidly and accurately. This method implements weight predictions on the basis of structure weight optimization with stiffness constraints and strength constraints, which include achievement of wing shape parametric modeling, rapid structure layout, finite element (FE) model automated generation, load calculation, structure analysis, weight optimization, and weight computed based on modeling. A software tool is developed with this wing weight estimation method. This software can realize the whole process of wing weight estimation with the method and the workload of wing weight estimation is reduced because much of the work can be completed by the software. Finally, an example is given to illustrate that this weight estimation method is effective.

• Nutrition Research and Practice
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• v.4 no.6
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• pp.499-506
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• 2010

The study aimed to analyze the lifestyles, weight control behavior, dietary habits, and depression of female university students. The subjects were 532 students from 8 universities located in 4 provinces in Korea. According to percent ideal body weight, 33 (6.4%), 181 (34.0%), 283 (53.2%), 22 (4.1%) and 13 (2.5%) were severely underweight, underweight, normal, overweight and obese, respectively, based on self-reported height and weight. As much as 64.1 % and only 2.4%, respectively, overestimated and underestimated their body weight status. Six overweight subjects were excluded from overestimation group for the purpose of this study, resulting in overestimation group consisting of only underweight and normal weight subjects. Compared to those from the normal perception group, significantly more subjects from the overestimation group were currently smoking (P=0.017) and drank more often than once a week (P=0.015), without any significant differences in dietary habits. Despite similar BMIs, subjects who overestimated their own weight statuses had significantly higher weight dissatisfaction (P= 0.000), obesity stress (P= 0.000), obsession to lose weight (P = 0.007) and depression (P = 0.018). Also, more of them wanted to lose weight (P = 0.000), checked their body weights more often than once a week (P=0.025) and had dieting experiences using 'reducing meal size' (P=0.012), 'reducing snacks' (P=0.042) and 'taking prescribed pills' (P = 0.032), and presented 'for a wider range of clothes selection' as the reason for weight loss (P = 0.039), although none was actually overweight or obese. Unlike the case with overestimating one's own weight, being overweight was associated with less drinking 0.035) and exercising more often (P=0.001) and for longer (P=0.001) and healthier reasons for weight control (P=0.002), despite no differences in frequency of weighing and depression. The results showed that weight overestimation, independent of weight status, is associated with risky lifestyles, weight control behaviors, and mental conditions. Preventive interventions should focus not only on obesity, but also on body weight overestimation.

• Journal of Ocean Engineering and Technology
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• v.23 no.3
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• pp.14-19
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• 2009

The present study developed a model to estimate the light weight of an ultra-large container ship. The weight estimation model utilized container ship data obtained from shipyards and the subdivided this weight data into appropriate weight groups. Parameters potentially affecting the group weight were selected and expanded based on experience for weight estimation, and a correlation analysis was performed by the SPSS program to determine the key parameters characterizing the group weight. A weight estimation model applying the multi-regression analysis was proposed to assess the weight of an ultra-large container ship at the preliminary design stage, and the results obtained by the suggested method showed good agreement with the shipyard data.

• Journal of the Korean Society of Clothing and Textiles
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• v.24 no.2
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• pp.192-198
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• 2000

This study was conducted in autumn and winter to investigate the wearing habit of the obese children in the cold. Eighty elementary school children were volunteered as the subjects. Forty of them were selected as the obesity group(OG) and the other forty children were selected as the normal body weight group(NG). Clothing weight and motor ability of the subjects were measured and correlation of the clothing weight between the children and their mothers were investigated. Clothing weight did not show significant difference between OG and NG in autumn but in winter. In winter, boys' lower clothing weight was less while girls' upper clothing weight was less in OG than in NG. Motor ability was better in NG than OG but no correlation was found between clothing weight and motor ability in both group except for upper clothing weight in NG. There was no correlation of total clothing weight between girls and their mothers but between boys and their mothers.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.17 no.3
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• pp.419-426
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• 2010

Purpose: Women's weight perception and obesity-related quality of life were analyzed according to BMI (Body Mass Index). Methods: A survey was conducted using self-report questionnaires from 178 participants. The data analysis included descriptive statistics, frequency, percentage, t-test, ANOVA, Fisher's exact test and Kendall's tau using the SPSS version 14.0. Results: There were significant differences in BMI according to age (F=8.037, p=<.001), weight perception (F=60.71, p<.001), weight control experience (F=2.504, p=.013), weight control method (F=5.839, p=.001) and weight control success (F=-2.451, p=.016). There was a significant difference in obesity-related quality of life according to weight perception in the low weight group (F=5.587, p=.021) and in the obesity group (t=3.419, p=.003). Higher correlations were found between the women's BMI group, weight perception and obesity-related quality of life. Conclusion: A program to provide appropriate information for weight perception is needed for the low weight group. There is a need for a program about weight reduction as well as weight perception for the obesity group.