• Nutrition Research and Practice
• /
• v.15 no.2
• /
• pp.203-212
• /
• 2021

BACKGROUND/OBJECTIVES: The branched-chain amino acids (BCAA), including isoleucine, leucine, and valine, promote muscle protein synthesis. However, obesity may interfere with protein synthesis by dysregulating mitochondrial function in the muscles. This study aimed to examine the association between dietary intake levels of BCAA and skeletal muscle mass index (SMI) in middle-aged participants, and the effect of obesity/abdominal obesity on this association. SUBJECTS/METHODS: The data of 3,966 men and women aged 50-64 years who participated in the 2008-2011 Korea National Health and Nutrition Examination Survey were analyzed. Intake levels of energy-adjusted dietary amino acids were obtained using a 24-hour dietary recall. SMI was calculated by dividing the appendicular skeletal muscle mass by body weight (kg) and multiplying the result by 100%. Multivariable general linear models were used to analyze the association of dietary BCAA intake levels with SMI. RESULTS: The beneficial effects of energy-adjusted dietary BCAA intakes on SMI were greater in the non-obesity/non-abdominal obesity groups; however, no significant associations were observed in the obesity/abdominal obesity groups (P > 0.05). CONCLUSIONS: Healthy weight and sufficient intake of dietary BCAA are recommended to maintain muscle mass.

• Steel and Composite Structures
• /
• v.44 no.1
• /
• pp.105-117
• /
• 2022

Impact resistance efficiency of the newly designed sandwich beam with a laterally arched core as bio-inspired by the woodpecker is numerically investigated. The principal components of the beam comprise a dual-core system sandwiched by the top and bottom laminated CFRP skins. Different materials, including hot melt adhesive, high-density polyethylene (HDPE), acrylonitrile butadiene styrene (ABS), epoxy resin (EPON862), aluminum (Al6061), and mild carbon steel (AISI1018), are considered for the side-arched core layer of the beam for impact efficiency assessment. The aluminum honeycomb takes the role of the second core. Contact force, stress, damage formation, and impact energy for beams equipped with different materials are examined. A diversity in performance superiority is noticed in each of these indicators for different core materials. Therefore, for overall performance appraisal, the impact resistance efficiency index, which covers several chief impact performance parameters, of each sandwich beam is computed and compared. The impact resistance efficiency index of the structure equipped with the AISI1018 core is found to be the highest, about 3-10 times greater than other specimens, thus demonstrating its efficacy as the optimal material for the bio-inspired dual-core sandwich beam system.

• Earthquakes and Structures
• /
• v.23 no.4
• /
• pp.339-352
• /
• 2022

Due to the large volume and generally as a public building, the damage of large-span space structures under various non-conventional loads will cause greater economic losses, casualties, and social impacts, etc. Therefore, it is particularly important to evaluate the seismic performance of large-span space structures. This paper taked a multipurpose sports center as an example and considered its synergistic deformation based on the method of equivalent damping ratio. Furthermore, The ABAQUS software was used to analyze the time-history and energy response of the multipurpose sports center under the action of rare earthquakes, and proposed a quantitative damage index to assess the overall damage of the structure. Finally, the research results indicated that the maximum inter-story drift ratio of the multipurpose sports center under the action of rare earthquakes was less than its limit value. The frame beams presented different degrees of damage, but the key members were basically in an elastic state. The bearing capacity did not reach the limit value, which satisfied the intended seismic performance target. This study taked an actual case as an example and proposed a relevant damage evaluation system, which provided some reference for the analysis of the seismic performance of large-span space structures.

• Journal of the Institute of Electronics Engineers of Korea SP
• /
• v.47 no.4
• /
• pp.90-96
• /
• 2010

The focusing system is an important factor to determine the imaging quality of a digital imaging system. The focusing system consist of measuring the focusing index with high frequency energy of an image and controlling the movement of the focusing lens based on the computed focusing index. The computation of the focusing index is a key aspect in implementing the focusing system and the noise of the image cause the error in the sharpness evaluation of the image. To reduce this error, the noise under the low illumination condition is considered. A noise insensitive focusing index using adaptive weights is proposed in this paper. This measure determines the sharpness of an image using the spatially adaptive weights based on the local statistics of the image and noise. Experimental results under the condition without and with the noise verify the performance of the proposed method.

• Tunnel and Underground Space
• /
• v.24 no.4
• /
• pp.325-333
• /
• 2014

Hydraulic fracturing is the key technology for production of shale gas, which is one of the major unconventional resources. Brittleness index is one of the most important mechanical properties which determine the efficiency of hydraulic fracturing. It was required that the production of shale gas increases with more brittle behavior. Confusingly, there are numerous definitions available for brittleness of rock. This paper summarizes various definitions of brittleness index, and presents correlation analysis of the brittleness indices by using the laboratory experimental results of 48 shale specimens in Korea. Generally, it shows a very weak positive correlation between the brittleness index ($B_1$) which is the ratio of uniaxial compressive strength to tensile strength and the brittleness index ($B_3$) which is calculated by using the Youngs modulus and Poisson's ratio. In addition, the role of Poissons ratio is not clear in defining brittleness indices. In conclusion, standardization of definition for brittleness index is required to apply it to hydraulic fracturing as a parameter for predicting the efficiency.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.9 no.6
• /
• pp.1696-1704
• /
• 2008

The conventional hard disk has been the dominant database storage system for over 25 years. Recently, hybrid systems which incorporate the advantages of flash memory into the conventional hard disks are considered to be the next dominant storage systems. Their features are satisfying the requirements like enhanced data I/O, energy consumption and reduced boot time, and they are sufficient to hybrid storage systems as major database storages. However, we need to improve traditional index management schemes based on B-Tree due to the relatively slow characteristics of hard disk operations, as compared to flashmemory. In order to achieve this goal, we propose a new index management scheme called FNC-Tree. FNC-Tree-based index management enhanced search and update performance by caching data objects in unused free area of flash leaf nodes to reduce slow hard disk I/Os in index access processes. Based on the results of the performance evaluation, we conclude that our scheme outperforms the traditional index management schemes.

• Korean Journal of Community Nutrition
• /
• v.11 no.6
• /
• pp.683-694
• /
• 2006

The purpose of this study was to determine the body weight control, food habits and nutrient intakes according to the obese index in male middle school students. This study was carried out through questionnaires and measurement by body fat analyzer (Inbody 4.0). The subjects were 275 male middle school students in Iksan. Chonbuk province. The average age, height, weight, and BMI of the subjects were 14.4 years old, 167.8 cm, 60.2 kg and $21.3kg/m^2$, respectively. Seventeen point one percent of the subjects were the underweight group, 47.6% were the normalweight group, and 35.3% were the overweight group by the classification of the Korean Pediatrics Society standard. Body fat of underweight, normalweight, and overweight were 16.1%, 19.0%, and 26.6%, respectively. Thirty one point nine percent of underweight, 39.7% of normalweight. and 31.9% of overweight had misperceptions of their weight (p<0.001). Sixty two point two percent of the males were dissatisfied with their body weight, and 55.3% of the whole tried to reduce their body weights. Even though they were normalweight, half of them dissatisfied with their weight. The source of weight control method was friends and family, TV radio, Internet, and school nutrition education, in order. The subjects exercised 3.4 days per week, 70.2 minutes per day, but it was not different significantly by the obese index. Forty percent of the subjects had meals fast, 58.5% of them have biased food habits even if they didn't differ by the obese index. Activity rate was different by the obese index significantly (p < 0.05), the number of severe activity was most in underweight. In conclusion, nutrition education programs should contain the necessity of normalweight, and regularity of lift habits and activities for energy expenditure in overweight students. It made them to recognize their weight correctly, establish healthy body images, and raise the ability to promote health and improve nutritional status.

• Korean Chemical Engineering Research
• /
• v.56 no.4
• /
• pp.547-554
• /
• 2018

Torrefaction is the promising process of pretreating biomass materials to increase the quality of their energy, especially to upgrade the materials' grindability so that it is suitable for a commercial pulverizer machine. In this study, torrefaction of oak, bamboo, oil palm trunk, and rice husk was carried out under different torrefaction temperatures ($300^{\circ}C$, $330^{\circ}C$, and $350^{\circ}C$) and different torrefaction residence times (30, 45, and 60 minutes). Complete characterization of the torrefied biomass, including proximate analysis, calorific value, thermogravimetric analysis, mass yield, energy yield, and grindability properties (Hardgrove Grindability Index) was carried out. Increasing the torrefaction temperature and residence time significantly improved the calorific value, energy density (by reducing the product mass), and grindability of the product. Furthermore, for commercial purposes, the torrefaction conditions that produced the desired grindability properties of the torrefied product were $330^{\circ}C-30minutes$ and $300^{\circ}-45minutes$, and the latter condition produced a higher energy yield for bamboo, oil palm trunk, and rice husk; however, torrefaction of oak did not achieve the targeted grindability property values.

• Journal of the Korean Solar Energy Society
• /
• v.32 no.3
• /
• pp.68-76
• /
• 2012

Since the solar energy resource is the main input for sizing any solar energy utilization system, it is essential to utilize the solar radiation data as an application and development of solar energy system increase. It will be necessary to understand and evaluate the insolation data. The Korea Institute of Energy Research(KIER) has begun collecting horizontal global insolation data since May, 1982 at 16 different locations in Korea and for the more detailed analysis, images taken by geostationary satellite may be used to estimate solar irradiance fluxes at earth's surface. It is based on the empirical correlation between a satellite derived cloud index and the irradiance at the ground. From the results, the measured data has been collected at 16 different stations and estimated using satellite at 44 different stations over the Korean peninsula from 1982 to 2010. The Result of analysis shows that the annual-average daily global radiation on the horizontal surface is 3.66 $kWh/m^2/day$ and estimated solar radiation fluxes show reliable results for estimating the global radiation with average deviation of -7.2 to +3.7 % from the measured values.

• Journal of the Korean Dietetic Association
• /
• v.11 no.2
• /
• pp.190-204
• /
• 2005

The purpose of this study was to investigate the dietary related factors and blood parameters of moderately or severely obese children residing in Samcheok. Anthropometric measurement, 24-hour recall for dietary intake, blood analysis and questionnaire response including nutritional knowledge, nutritional attitude, body image recognition and eating habits were conducted in 23 obese children(16 boys and 7 girls) and their mother. The mean age of subjects are 10.0 years. The average body weight, BMI, obesity index and percent body fat were 57.5㎏, 27.0㎏/$m^2$, 47.3 and 38.1% in boys and 51.0㎏, 24.8㎏/$m^2$, 40.3 and 43.9% in girls. The average nutritional attitude, the self-satisfaction and the nutritional knowledge scores in subjects were 29.9/40, 32.7/50 and 7.3/10, respectively. 34.8% of the subjects were unsatisfied with their body image, whereas, 81.8% of their mothers were unsatisfied with children’s body image. 60.9% of subjects had one or both obese parents. Average intake of energy were 90.6% of RDA in boys and 84.3% of RDA in girls. The ratio of energy from carbohydrate/protein/fat were 66/16/18 in boys and 66/17/17 in girls. The mean serum cholesterol concentration of the subjects was 191.8mg/dl and 78.3% of the subjects were above the normal serum cholesterol rage of children. In the results of correlation analysis, obesity index was negatively correlated with self and mother’s nutritional attitude scores. Body weight and BMI were positively correlated with vitamin C(p<0.05) and fruits(p<0.05) intakes. And there was a positive correlation between obesity index and BMI, and serum cholesterol(p<0.05).