• The Korean Journal of Physiology
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• v.2 no.2
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• pp.101-135
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• 1968

As physical fitness measured was muscle strength (hand grips, leg extention, back lift, and arm pull and thrust), skinfold thickness (5 different sites), circulatory function (resting heart rate and blood pressure), speed (kinesiological analysis during 100m sprint, record, maximal and final speed), motor function (50 meter dash, ball throwing, standing broad jump, and pull-ups), maximal aerobic power (maximum oxygen intake by field running method), muscle power (leg and arm by inertia ergometer), and general endurance (maximum endurance running time on the treadmill at the speed of 5 MPH and grade of 15.5%) of 1131 Korean children (boys 572, girls 559) aged of 6 to 17 years, who were randomly sampled from 24 primary, middle and high schools at the two districts of Seoul and KyungKi. The results are summarized as follows: 1) The status (height and weight) of the children was almost same as that of the previously reported Korean and Japanese children of same ages. 2) Muscle strength was a gained linearly with geting age in the boys and girls but there was a little improvement in girls aged of 13 years or more. 3) The mean skin fold thickness was increased linearly with geting ages in both sexes, but the girls from 12 to 17 years of age were increased rapidly, and maximum value was 17mm, while boys was 7.0 mm. 4) In the circulatory function, the resting heart rate was decreased, but the blood pressure was increased with ages in both sexes within the normal limits. 5) The maximum and final speed during 100 meter sprint increases with age in boys but girls who are 12 years old or older, were not improved any mere. The patterns of running were same in both sexes, and maximum speed reached at about 30 meters from starting line. 6) The motor function was increased with age in both sexes, but there was no improvement in 12 years of age or older girls. More over records of all functions except standing broad jump was less than those of Japanese in the same age, respectively. 7) The maximum oxygen intake (MOI) was increased considerably with ages and maximum values were 2.93 L/min (boys) and 2.09 L/min (girls) at the age of 17years. This result was almost same as that of the Japanese and Easter Island population, but the value was lower than that of Europe. The average of the maximum oxygen intake per kg body weight per minute from 9 to 17 years of age were around 53 ml in the boys and 42 ml in the girls. 8) Muscle power was increased linearly with ages in boys while there was relatively a little increment in girls. The maximum values of leg muscle in boys and girls at the 17 years of age were 0.168 and 0.088 horse power, respectively. 9) The maximum endurance running time was increased considerably from the age of 9 in boys, while there was no improvement in girls. The maximum values were 6.0 min and 1.8 min, respectively.

• Archives of design research
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• v.18 no.3 s.61
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• pp.85-94
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• 2005

Most of product designers use 3D CAD system as a inevitable design tool nowadays and many new products are developed through a concurrent engineering process. However, it is very difficult for novice designers to get the sense of reality from modeling objects shown in the computer screens. Such a intangibility problem comes from the lack of haptic interactions and contextual information about the real space because designers tend to do 3D modeling works only in a virtual space of 3D CAD system. To address this problem, this research investigate the possibility of a interactive quantified structure simulation for product design using AR(augmented reality) which can register a 3D CAD modeling object on the real space. We built a quantified structure simulation system based on AR and conducted a series of experiments to measure how accurately human perceive and adjust the size of virtual objects under varied experimental conditions in the AR environment. The experiment participants adjusted a virtual cube to a reference real cube within 1.3% relative error(5.3% relative StDev). The results gave the strong evidence that the participants can perceive the size of a virtual object very accurately. Furthermore, we found that it is easier to perceive the size of a virtual object in the condition of presenting plenty of real reference objects than few reference objects, and using LCD panel than HMD. We tried to apply the simulation system to identify preference characteristics for the appearance design of a home-service robot as a case study which explores the potential application of the system. There were significant variances in participants' preferred characteristics about robot appearance and that was supposed to come from the lack of typicality of robot image. Then, several characteristic groups were segmented by duster analysis. On the other hand, it was interesting finding that participants have significantly different preference characteristics between robot with arm and armless robot and there was a very strong correlation between the height of robot and arm length as a human body.

• Journal of radiological science and technology
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• v.40 no.4
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• pp.581-587
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• 2017

This study was based on the data of total mineral content of about 99% at the age of 16-26 years, we aimed at female university students who are important for bone formation in their early 20s. The purpose of this study was to investigate factors of eating habits affecting their bone density and to provide data to prevent osteoporosis which might occur in the future. It was conducted on 100 female university students in their 20s, the bone mineral density according to BMI was measured by DEAX, and the analysis of 10 eating habits items and the results of BMD measurement on their own results in Excel 2010. As a result, the height was $161.08{\pm}4.70cm$, the weight was $52.43{\pm}6.43kg$, and the BMI was $20.22{\pm}2.48$, which correlated with BMD (p<0.05). According to the BMI classification, 20 had low weight and 80 had normal weight, and BMD was $0.20{\pm}0.41$ at normal weight. In the same sex, the mean T-score of the young adult group was $-0.04{\pm}0.99$ compared with the BMD of the young adult group, and the mean Z-score of the same age group was $0.02{\pm}0.93$ (p<0.001). Eating habits affecting bone mineral density were significantly affected by 3 meals per day, 1-3 cups of coffee per day and p<0.05 for Low salt formula intake. 6-9 dairy product intake was also p<0.05 but not significant. Therefore, it is considered that when 20s female students become middle-aged woman, they should have proper eating habits so that osteogenesis can be improved at young age in order to prevent bone disease.

• Fire Science and Engineering
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• v.31 no.5
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• pp.53-62
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• 2017

Electric power which is the energy source of economy and industries requires long distance transportation due to regional difference between its production and consumption, and it is supplied through the multi-loop transmission and distribution system. Prior to its actual use, electric power flows through several transformations by voltage transformers in substations depending on the characteristics of each usage, and a transformer has the structure consisting of the main body, winding wire, insulating oil and bushings. A transformer fire that breaks out in substations entails the primary damage that interrupts the power supply to houses and commercial facilities and causes various safety accidents as well as the secondary economic losses. It is considered that causes of such fire include the leak of insulating oil resulting from the destruction of bottom part of bushings, and the chain reaction of fire due to insulating oil that reaches its ignition point within 1 second. The smoke detector and automatic fire extinguishing system are established in order to minimize fire damage, but a difficulty in securing golden time for extinguishing fire due to delay in the operation of detector and release of gas from the extinguishing system has become a problem. Accordingly, this study was carried out according to needs of active mechanism to prevent the spread of fire and block the leak of insulating oil, in accordance with the importance of securing golden time in extinguishing a fire in its early stage. A bushings fireproof structure was developed by applying the high temperature shape retention materials, which are expanded by flame, and mechanical flame cutoff devices. The bushings fireproof structure was installed on the transformer model produced by applying the actual standards of bushings and flange, and the full scale fire test was carried out. It was confirmed that the bushings fireproof structure operated at accurate position and height within 3 seconds from the flame initiation. It is considered that it could block the spread of flame effectively in the event of actual transformer fire.

• Journal of Nutrition and Health
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• v.31 no.7
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• pp.1139-1150
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• 1998

The purpose of this study is to investigate the effects of the silkworm powder on blood levels of glucose, Hb Alc, insulin, and lipids. Thirty-one NIDDM patients from Kyung Hee Medical Center were divided into two groups : patients with silkworm powder supplements and drug treatments(Drug diabetes) and patients with silkworm powder supplement only(Non-drug diabetes). For the control group, age-matched subjects were recruited. During the 4 weeks of the experimental period, silkworm powder(500mg/mea1) was given to the subjects right after each meal. Nutritional assessments and dietary education were carried out periodically, and body weight and blood pressure were measured when patients visited the hospital. Overnight fasting and 2-h postprandial blood glucose levels were measured at 2 week intervals. The blood levels of insulin, Hb Alc, and lipids were measured before and after the supplements. The mean ages of the three groups were 56.7-59.6 years old. The height, weight, and BMI did not differ among the groups. The fasting blood glucose levels were 138.1$\pm$22.0mg/dl for the Drug treated diabetes group, 175.0$\pm$32.0mg/dl for the Non-drug diabetes group, and 108. 3$\pm$16.gmg/dl for the control group at the begining of the supplement. After 4-wks of supplements, the blood levels of glucose tended to decrease in all three experimental groups. Before the supplements, the 2-h postprandial blood glucose levels of the Drug diabetes, Non drug diabetes, and control groups were 244.7$\pm$62.6mg/dl, 272.4$\pm$40.1mg/dl, and 147.7$\pm$28.0mg/dl, respectively. After the supplement, the levels were 197.2$\pm$30.gmg/dl, 208.6$\pm$ 56.6mg/dl, and 151.3$\pm$30.3mg/dl, respectively. This shows that silkworm powder tended to lower blood levels by 19.4% and 23.4% in NIDDM patient groups. However, the changes in the blood levels of insulin, Hb Alc, ind lipids were not observed after the supplement. In conclusion, the present study has demonstrated that silkworm powder has a tendency to decrease 2-h postprandial blood glucose levels, but it should be used with caution in controlling the diabetes. (Korean J Nutrition 31(7) 1139-1150, 1998)

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.7
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• pp.866-873
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• 2006

The purpose of this study was to evaluate the current dietary habits, health related behaviors, nutrition knowledge and body indices, and to investigate the changes in nutrition knowledge for designing and monitoring nutrition education program among preschool children. The subjects were 1,200 preschool children, aged $4{\sim}6$ years. A measurement of the height and weight was conducted. The general home environment, the dietary habit of children and nutrition knowledge were collected using a questionnaire that included information about family income, parent's education and occupations. Using the PIBW, 14.6% of the preschool children were under weight, 54.4% were normal, and 31.0% were overweight or obese. We regarded to food habit score, the highest score was in the regularity of breakfast, while the lowest score was in consumption of yellow-green vegetables such as spinach and carrots. Result in food behavior showed that 69.1% of preschool children had a unbalanced diet, and their favorite snack was fast food like pizza and hamburger then followed soft drink and fried foods (chicken of potato). After nutrition education, there was somewhat improvement in the nutrition knowledge score of preschool children from $7.7{\pm}1.7$ point to $8.9{\pm}1.5$ point. These results suggest that nutrition education help preschool children change their nutrition knowledge. Therefore, it would be needed that new appropriate nutrition education to improve dietary habits and health status.

• Journal of the Korean Society of Food Science and Nutrition
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• v.20 no.2
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• pp.103-110
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• 1991

This study was conducted to determine riboflavin status of young healthy Korean women. Eight subjects consumed general Korean diet for 3 weeks. Riboflavin intake was measured during the period and Erythrocyte Glutathione Reductase Activity coefficient (EGRAC) was analyzed at the end of experimental period. The subjects who showed EGRAC value above 1.20 were supplemented 6 mg riboflavin per day for 1 week. The average age of subjects was 22.1 years old, height was 154.4cm, weight was 49.2kg, chest circumference was 81.2cm, the sum of skinfold thickness of 3 parts was 79.5mm and Body Mass Index(BMI) was 20.6. Hemoglobin concentration was 13.0g/100ml, hematocrit value was 44.0% A/G ratio was 1.4, and the activity of sGOT, sGPT, alkaline phosphatase was 14.3, 11.0 and 6.5, respectively. The average daily intake of energy, protein and riboflavin was 1745kcal, 56.1g and 1.14mg, respectively. The mjor source of riboflavin were milk, egg, Korean cabbage, rice, beef and so on. The average EGRAC value was 1.2748. percentages of subjects who showed EGRAC value above 1.20 was 65.2%. After oral administration of 6mg riboflavin, the EGRAC value of all these subjects was returned to normal range. Riboflavin intake was correlated positively with energy as well as protein intake, and correlated negatively with EGRAC value. However, riboflavin intake per 1,000kcal was not correlated with EGRAC value.

• Korean journal of health promotion
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• v.17 no.2
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• pp.109-118
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• 2017

Background: Abdominal obesity as measured by waist-to-height ratio (WHtR) may have stronger and inverse associations with cardiovascular (CV) health than overall obesity as measured by body mass index (BMI). However, there was some challenges for controversies. We aimed to examine the associations of WHtR and BMI with CV health among Korean children using data of the 2010-2012 Korea National Health and Nutrition Examination Survey. Methods: A cross-sectional study was conducted with the sample of 2,363 children by analyzing by gender and two-age groups (10-12 and 13-18 years). Overall obesity was categorized into 3 groups by BMI percentile: non-overweight (<85), overweight (${\geq}85$), and obesity groups (${\geq}95$). Abdominal obesity was categorized into 2 groups by WHtR: normal (<0.5) and abdominal obesity groups (${\geq}0.5$). The CV health score was defined as a z-score by calculating the sum of 7 CV factors. Results: The overweight/obesity groups had significantly lower CV health scores than the normal group (P<0.05) in boys and girls aged either 10-12 years or 13-18 years after adjusting for covariates. The abdominal obesity group also showed significantly lower CV health scores than the normal group (P<0.05) in all the groups; this significant association remained significant in boys aged 13-18 years even after further adjusting for BMI category (P<0.01). Conclusions: Among boys aged 13-18 years, abdominal obesity as measured by WHtR was significantly and inversely associated with CV health, independent of BMI category. Therefore, it should be considered to assess the level of abdominal obesity as a measure of CV health in late adolescent boys.

• Journal of the Korean Orthopaedic Association
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• v.56 no.3
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• pp.208-214
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• 2021

Purpose: Verifying a reliable predictor of the progression of vertebral deformity in patients with acute osteoporotic fractures of the lumbar spine may be useful. A qualitative analysis of the muscle near the spine was performed using magnetic resonance imaging (MRI), and its correlation with a spinal deformity was determined under the hypothesis that the causes of the kyphotic deformity are associated with muscle reduction in the multifidus and erector spinae. Materials and Methods: The study was performed in a retrospective manner using the electronic medical records of patients who presented to the author's institution between January 2007 and March 2018, and were diagnosed with an acute lumbar fracture. The fat infiltration rates of the multifidus and erector spinae were measured using MRI taken at the time of injury, and the mean value was defined as the total fat infiltration rate (TFI). Based on lateral radiographs of the lumbar spine at the one-year follow-up, the loss of height of the vertebral body, the kyphotic angle and the wedge angle were measured. The statistical significance was confirmed by calculating the Pearson correlation coefficient. Results: One hundred twenty-nine patients, of which 30 were male and 99 were female, were examined. The mean age was 71.28 years. The mean T-score was -3.53±0.79 g/cm², and the mean fat infiltration was 15.20%±11.99%. TFI was positively correlated with age (R=0.373, p<0.001), compression rate (R=0.369, p<0.001), and Cobb's angle (R=0.386, p<0.001) after a one year follow-up, but negatively correlated with the BMD score (R=-0.252, p=0.004). As the fracture progressed to the lower lumbar level, the compression rate (R=-0191, p=0.030) and wedge angle (R=-0.428, p<0.001) at the time of injury tended to decrease. Conclusion: In patients with osteoporotic vertebral fractures, the fat infiltration rate may be an important predictor of conservative treatment. The prognosis of patients with a high-fat infiltration rate should be explained during patient education, and the patients must be monitored closely through short-term outpatient follow-up.

• Journal of the Korean Applied Science and Technology
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• v.39 no.1
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• pp.63-73
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• 2022

The aim of this study was to cluster according to the bone age of elementary school students in order to analyze the physique, physical fitness, and skeletal maturation of each cluter group and to provide basic data for the balanced development of elementary school students through data analysis. The subjects of this study were 2243 students aged 8 to 13 years, and the skeletal maturation were calculated by applying them to the TW3 method score conversion table after the X-ray films were taken. A total of 2 components in physique were measured using a stadiometer(Hanebio, Korea, 2021) and the Inbody 270(Biospace, Korea, 2019), and a total of 7 components in physical fitness, which included muscular strength(Hand Grip Strength), balance(Bass Stick Test), agility(Plate Tapping), power(Standing Long Jump), flexibility(Sit&Reach), muscular endurance(Sit-Up), and cardiovascular endurance(Shuttle Run) were measured as well. K-Means clustering method, cross-tabulation analysis, and one-way variable analysis(ANOVA) were conducted for data processing using the SPSS PC/Program(Version 26.0) and Bristics Studio Tool, and it was considered significant at the level of p< .05. The results of this study may be summarized as follow. First, as a result of clustering using three components of skeletal maturation: retarded, normal, and advanced, cluster 1(Retarded) showed excellence in muscular strength, balance, and agility. cluster 2(Normal) showed poor flexibility, whereas cluster 3(Advanced) showed excellence in muscular strength. Second, as a result of analyzing the differences in physique according to the clustering of elementary school students by their individual characteristics, cluster 3(Advanced) showed excellence in height, weight, and body fat percentage. Third, as a result of analyzing the differences in physical fitness according to the clustering of elementary school students by their individual characteristics, cluster 3(Advanced) showed excellence in Hand Grip Strength(Left, Right), whereas cluster 1(Retarded) showed excellence in Bass Stick Test, and cluster 3(Advanced) showed excellence in Standing Long Jump.