• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.5
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• pp.877-886
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• 2019

The energy band gaps and optical constants of zincblende $In_yGa_{1-y}As_{1-x}N_x$ on the variation of temperature and composition are determined by using band anticrossing method. The energy band gaps are decreasing continuously in $In_yGa_{1-y}As_{1-x}N_x$ ($0{\leq}x{\leq}0.05$, $0{\leq}y{\leq}1.0$, 300K) and the bowing parameter is calculated as 0.522eV. The calculation results of energy band gaps are consistent with those of other studies. A refractive index n and a high-frequency dielectric constant ${\varepsilon}$ are calculated by a proposed modeling equation using the results of energy band gaps.

• Tunnel and Underground Space
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• v.33 no.5
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• pp.425-434
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• 2023

To measure the wear amount of the TBM disk cutter in real time, it is important not only to automate the measurement using sensors, but also to stably transmit the measured data to the information processing system. In this study, we investigated the viability of utilizing Bluetooth Low Energy (BLE) technology to wirelessly transmit sensor data from the TBM cutter head to a receiver located at the chamber's rear. Through laboratory experiments, we analyzed the Received Signal Strength Index (RSSI) of the receiver considering various signal strength of the transmitter, separation distances between the transmitter and receiver and chamber fill materials. Our results demonstrate that wireless data transmission is feasible across all tested conditions when the transmitter signal strength is 0 dBm or higher.

• Proceedings of the Korea Concrete Institute Conference
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• 1999.10a
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• pp.593-596
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• 1999

Steel fibers are added to concrete to improve energy absorption, impact resistance and apparent ductility, and to provide crack resistance and crack control. This study is to investigate the toughness index and post-crack equivalent tensile strength of steel fiber reinforced concrete properties on the load-deflection behaviors of the steel fiber reinforced concrete beam model specimens.

• Transactions on Electrical and Electronic Materials
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• v.18 no.2
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• pp.111-118
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• 2017

The increased diversity of different types of energy sources requires moving towards smart distribution networks. This paper proposes a probabilistic DG (distributed generation) units planning model to determine technology type, capacity and location of DG units while simultaneously allocating ESS (energy storage systems) based on pre-determined capacities. This problem is studied in a wind integrated power system considering loads, prices and wind power generation uncertainties. A suitable method for DG unit planning will reduce costs and improve reliability concerns. Objective function is a cost function that minimizes DG investment and operational cost, purchased energy costs from upstream networks, the defined cost to reliability index, energy losses and the investment and degradation costs of ESS. Electrical load is a time variable and the model simulates a typical radial network successfully. The proposed model was solved using the DICOPT solver under GAMS optimization software.

• Journal of the Korean Solar Energy Society
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• v.25 no.2
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• pp.9-17
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• 2005

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. For the validation, estimated solar radiation fluxes are compared with observed solar radiation fluxes at 16 sites over the Korean peninsular from January 1982 to December 2004. Estimated solar radiation fluxes show reliable results for estimating the global radiation with average deviation of -7.8 to +7.0% from the measured values and the yearly averaged horizontal global insolation of Korean peninsula was turned out to be $3.56kW/m^{2}/day$.

• Journal of the Korean Dietetic Association
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• v.3 no.2
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• pp.182-196
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• 1997

Physiological changes that affect nutrient absorption and utilization occur in older adults, and the collection of nutritional information is an important part of examining the nutrition and health issue. A nutritional survey using the 24-hour recall method was performed to identify nutritional quality and leading patterns of food group intake for protein, vitamin C, P and Fe were over 1, whereas those for vitamin A, $B_1$, $B_2$, niacin and Ca were below 1. The MAR(Mean Adequacy Ratio) was relatively low(0.75). The percentage of energy from carbohydrate, protein, and fat was 65.1, 15.6, and 19.5, respectively, thus the quantities of energy source were ideal. The Older subjects revealed poorer nutrition quality than the younger subjects did. The food group intake pattern of the elderly was not diverse, only 9% of them consumed all food groups in a day. These results suggest that nutritional guidelines for older Koreans should focus on the maintenance of adequate energy intake. In addition, selection of foods with high protein and calcium, such as dairy food, should be emphasized, particularly in the older elderly. Nutrition programs should target individuals at risk of not receiving enough nutrients, like the oldest elderly, and persons with lower education.

• Korean Journal of Community Nutrition
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• v.6 no.3
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• pp.486-494
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• 2001

This study was performed to assess the nutrient intakes and diet quality of rural middle school students provided with and without the national school lunch program(NSLP). The data on dietary intakes were obtained by using food record method questionnaires which were collected from 340 rural middle school students provided with(n=177) and without (n=163) NSLP. Diet quality was accessed by NAR(nutrient adequacy ration), MAR(mean adequacy ration), and INQ( index of nutritional quality). Total energy intakes of the boys were 2123 kcal with NSLP and 1857 kcal without NSLP. Total energy intakes of the girls were 1913 kcal with NSLP and 1814 kcal without NSLP. Phosphorus, vitamin A, vitamin E, ascorbic acid, thiamin, riboflavin, and niacin intakes were above the RDA in the NSLP group. For those without NLSP, phosphorus, vitamin E, thiamin intakes were above RDA, however, calcium, iron vitamin A, vitamin $B_6$ were less than the RDA. The mean adequacy ration(MAR), an index of dietary quality was 0.69(with) 0.62(without) for males and 0.62(without) for females The indexes of nutritional quality(INQ) were over 1 for most nutrients except calcium, vitamin A, vitamin B$_2$ and zinc. The study showed that total daily energy and nutrient intakes were significantly higher in students provided with than those without school-lunches. Thus, the school-lunch program is recommenced and necessary to improve the nutritional status of middle school students.

• Korean Journal of Community Nutrition
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• v.6 no.3
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• pp.306-316
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• 2001

This study investigated the correlations between nutrient intake and dietary attitudes in Korean school dietitians. A total of 493 school dietitians working in the Kangwon and Kyungnam areas participated in this study. The subjects were classified as the good group(33.5%), fair group(36.9%) and bad group(29.6%) based on dietary attitude score. The results were as follows. The average intake of energy, calcium, and iron were lower than the Korean RDA and average CPF ratio of energy intake was 64 : 17 : 19. The percent RDAs of nutrient intake of energy, calcium, iron and vitamin B$_1$were lower in the bad group than those in the fair group and good groups(p < 0.001). The mean adequacy ratio(MAR), an index of overall dietary quality, were different among the three groups(p < 0.001), the highest was 0.96 in the good group, the lowest was 0.88 in the bad group. The index of nutritional quality(INQ) was significantly higher in the good group than the other groups. The nutrient intakes were positively correlated with dietary attitudes(p < 0.01). The nutrient intakes, INQ, NAR and MAR were significantly increased as the dietary attitude score increased.

• Journal of Nutrition and Health
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• v.40 no.2
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• pp.172-181
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• 2007

This study was performed to evaluate served menu in Korean temples. Among available temples in the nation, 34 temples were carefully selected considering location and the gender characteristics. A five consecutive day menu was collected to analyse by interview between Jan 2004 and Aug 2004. Mean energy content of menu was 1633.8 kcal, with 67.3% of energy supplied by carbohydrate, 14.8% by protein and 17.9% by fat. Beans and bean products were the major contributing dishes for most nutrients. Contents of most nutrients except energy, protein and vitamin B were higher than RDA. Nutrient adequacy ratio (NAR) were 0.9-1.0 and mean adequacy ratio (MAR) was 0.9 for temples. Total number of dishes from menu was 7.3. Dietary variety score (DVS) was 26.4 and buddhist monk temples offered more diverse foods than buddhist nun temples. KDQI (Korean diet Quality Index), overall diet quality index were 0.67 and those of buddhist nun temples were better than those of buddhist monk temples. From the result of this study it was concluded that the temple diet is nutritionally well balanced, rich in dietary fiber and low in cholesterol. So it can be a healthy diet for the modern person. This is the very first study attempting the nationwide investigation of temple diet in Korea. It will be used as fundamental data to improve quality of diet to prevent modern chronic disease.

• Journal of Korean Society of Water and Wastewater
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• v.28 no.2
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• pp.225-233
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• 2014

This paper presents a Computational Fluid Dynamics(CFD) based simulation and experimental tracer test of flow pattern and turbulent energy dissipation inside a serpentine flocculation basin with continuous operation. Research focused on the evaluation of a specific flow pattern on the hydraulic behavior on the flocculation basin. From the results of CFD simulation and actual tracer test, both results were in good accordance with each other. Also, each Morill index were calculated as 1.5 from CFD simulation and 1.7 from actual tracer test, respectively. Especially, turbulence energy was dissipated relatively higher in the vicinity of inlet to the flocculation basin than other region. The differences between the CFD simulation and actual tracer test were 1.4 min in $T_{50}$, and 1.3 min in $T_p$, respectively.