• Food Science and Biotechnology
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• v.15 no.4
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• pp.589-594
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• 2006

The effect of five commercial gums (carboxylmethylcellulose, CMC; guar gum, GG; hydroxypropylmethyl-cellulose, HPMC; locust bean gum, LBG; and xanthan gum) at a concentration of 0.25% on the rheological properties of rice flour (RF) dispersions was investigated in steady and dynamic shear. The steady shear rheological properties showed that RF gum mixture dispersions (5%, w/w) at $25^{\circ}C$ had high shear-thinning flow behavior (n=0.20-0.31) exhibiting a yield stress. Magnitudes of consistency index (K), apparent viscosity (${\eta}_{a,100}$), and Casson yield stress (${\sigma}_{oc}$) of RF-gum mixtures were much higher than those of RF dispersion with no added gum (control). Activation energy values (6.67-10.8 kJ/mole) of RF-gum mixtures within the temperature range of $25-70^{\circ}C$ were lower than that (11.9 kJ/mole) of the control. Dynamic rheological data of log (G', G") versus log frequency (${\omega}$) of RF-gum mixtures had positive slopes (0.15-0.37) with G' greater than G" over most of the frequency range (0.63-63 rad/sec), demonstrating a frequency dependency. Tan ${\delta}$ (G"/G') values of RF-gum mixtures, except for xanthan gum, were much higher than that of the control.

• Korean Journal of Food Science and Technology
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• v.16 no.3
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• pp.273-278
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• 1984

Changes in rheological properties of rice starch-water systems during the gelatinization were evaluated with the tube viscometer at temperatures between 50 and $85^{\circ}C$ and for the concentrations ranging from 3-5% rice starch. The flow consistency index increased exponentially with time at a particular temperature while being linearly dependent upon the concentration. The gelatinization rate measured by rheological method followed Arrhenius type equation. The value of activation energy of gelatinization for 5% rice starch was about 25 kcal/g mol.

• Journal of Nutrition and Health
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• v.31 no.7
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• pp.1174-1182
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• 1998

The purpose of this study was to compare the nutritional status and the immunocompetence of elderly women residing in urban and rural areas. Dietary food records and anthropometric measurements were used to evaluate the nutritional status of subjects. The immune function of subjects was assessed by total and differential white blood cell(WBC) counts. Total B and T Lymphocytes, and T cell subsets were quantified by flow-cytometer. Immunoglobulin G, A, and M concentrations were also measured as an index of humoral immunity. Elderly women in rural area showed a relatively lower dietary intake of total energy, protein, and iron than did urban elderly women. Total WBC, neutrophil counts, eosinophil counts, and the percentage of neutrophils among total leukocytes were significantly higher in urban elderly women than in rural women. Although the numbers of lymphocytes were not significantly different, the percentage of Lymphocytes among total leukocytes as greater in rural elderly women than in urban. Both groups did not show any significant differences in numbers of T cell subsets and NK cells. Immunoglobulin G, A, and M levels were not significantly different between the two groups, but the numbers of subjects placed under the deficient range of immunoglobulins were greater in rural than in urban elderly women. from the present study, it could be suggested that poor nutritional intake may selectively affect the number of immune cells, thereby influencing the immunocompetence of elderly women. (Korean J Nutrition 31(7) 1174-1182, 1998)

• Journal of Nutrition and Health
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• v.36 no.10
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• pp.1042-1051
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• 2003

To study the level of change in food and nutrient intake among different age groups, a dietary survey using the 24-hour recall method was conducted among 80 female elementary school children, 84 high school students, 100 adults from 25 to 35 years old and 120 elderly people over 60 years of age. The results of the study showed that plant food and total food intake were higher in adults and animal food intake was significantly higher in children. The percentage of plant food to total food intake was highest in the elderly and that of animal food to total food intake was highest in the children. The elderly consumed significantly less meat and poultry and more fish than the other groups. However, the children consumed significantly higher amounts of milk and dairy products. The elderly had the lowest Ca intake. Carbohydrate energy intake in the elderly was 70.3％, significantly higher than that for the other age groups. All of the age groups consumed a quantity of Ca below the Korean RDA and 77.5％ of the elderly consumed an amount below 75％ of the RDA. Nutrient adequacy ratio (NAR) of most nutrients was lowest in the elderly. Mean adequacy ratio (MAR), an index of overall dietary quality, was 0.88 for the children, 0.84 for the adolescents, 0.80 for the adults, and 0.70 for the elderly. Therefore, the results show that food and nutrient intake changes with advancing age, and the overall quality of the diet of elderly people is lower than that for the other age groups.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2012.05a
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• pp.236-237
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• 2012

ZnO nanorods were grown on R-plane sapphire substrates with the seed layers annealed at different temperature. The effects of annealing temperature for the seed layers on the properties of the ZnO nanorods were investigated by scanning electron microscopy, X-ray diffraction, UV-visible spectroscopy, and photoluminescence. For the as-prepared seed layers, the ZnO nanorods and the ZnO nanosheets were observed. Only the ZnO nanorods were grown as the annealing temperature was above $700^{\circ}C$. The optical transmittance in the UV region was almost zero while that in the visible region was gradually increased as the annealing temperature increased to $700^{\circ}C$. The optical band gap of the ZnO nanorods was increased as the annealing temperature increased to $700^{\circ}C$. In the visible region, the refractive index was decreased with increasing the wavelength, and the extinction coefficient was decreased as the annealing temperature increased to $700^{\circ}C$. The non-linear exciton radiative life time of the FX emission peak was established by cubic equation. The values of Varshni's empirical equation fitting parameters were ${\alpha}=4{\times}10^{-3}eV/K$, ${\beta}=1{\times}10^4K$, and $E_g(0)=3.335eV$ and the activation energy was found to be about 94.6 meV.

• Preventive Nutrition and Food Science
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• v.4 no.3
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• pp.184-187
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• 1999

Increase in fat mobilization by capsaicin(CAP) was investigated in high-fat-fed mice using an adjustable current water pool. Male ICR 7-wk-old mice were fed a high fat diet [50% total energy content in the diet(E%) fat, 20 E% protein, 30E% carbohydrate] for 2 wk and one group (HCAP) was orally administered CAP at 2 h before swimming. After being accustomed to swimming , the mice were subjected to forced swimming every 2d in the current water pol and the total swimming period until exhaustion was measured . The total swimming period was used as index of swimming capacity. Swimming time to exhaustion of treated mice was significantly longer than that of the high-fat-fed control group (100.2$\pm$10.6 vs. 58.0$\pm$8.5min, P<0.01) after 2wk of training. The concentration of serum-free fatty scids gradually increased up to 2 h in CAP -administered mice. The perirenal adipose tissue weight of CAP -administered mice (HCAP) before swimming was lower than that of the high-fat-fed mice adminstered placebo solution (HP) which had not ingested CAP during the 2 wk. These results suggest that the increase of swimming capacity of CAP-administered high-fat-fed mice was due to an increase of fat mobilization that was induced by CAP.

• Korean Journal of Remote Sensing
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• v.20 no.1
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• pp.1-11
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• 2004

Based on surface energy balance climatology, surface temperatures should respond to drying conditions well before plant response. To test this hypothesis, land surface temperatures (LST) derived from MODIS data were analyzed to determine how the data were correlated with climatic water balance variables and NDVI anomalies during a growing season in Western and Central Kansas. Daily MODIS data were integrated into weekly composites so that each composite data set included the maximum temperature recorded at each pixel during each composite period. Time-integrated, or cumulative values of the LST deviation standardized with mean air temperatures had significantly high correlation coefficients with SM, AE/PE, and MD/PE, ranging from 0.65 to 0.89. The Standardized Thermal Index (STI) is proposed in this study to accomplish the objective. The STI, based on surface temperatures standardized with observed mean air temperatures, had significant temporal relationships with the hydroclimatological factors. STI classes in all the composite periods also had a strong correlation with NDVI declines during a drought episode. Results showed that, based on LST, air temperature observations, and water budget analysis, NDVI declines below normal could be predicted as early as 8 weeks in advance in this study area.

• Bulletin of the Korean Chemical Society
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• v.17 no.7
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• pp.604-607
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• 1996

Semiempirical PM3 MO calculations are applied to estimate both 1-atom (X=S,O,C) and 3-substituent (Y=R, CH2R, SR, CH2SR) effects on the reactions of some 1-atom-replaced and 3-substituted cephem-like β-lactam compounds of thiacephems, oxacephems, and carbacephems. Stabilization energy (SE) of the reaction intermediate for the reaction with a hydroxyl ion can be used to evaluate the facility of a reaction and selected as a chemical reactivity index. With the 1-atom effect only, the SE values obtained imply that thiacephems are generally more reactive than the other two cephem-like molecules and the reactivity order is thiacephems>oxacephems>carbacephems. When it comes to the 3-substituent (Y=R, CH2R, SR, CH2SR) effect, chemical reactivity can be best realized by using a 3-substituted thiacephem molecule capable of giving a resonance-stabilized and electron-rich leaving group after the reaction with a nucleophile. SE values, however, decrease in most cases when an additional intervening ethylene group is present (Y=CH2R, CH2SR). The overall 3-substituent reactivity tendency is SR>CH2SR>R>CH2R.

• Journal of Power Electronics
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• v.19 no.6
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• pp.1351-1365
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• 2019

This paper proposes two modified Z-source inverter topologies, namely an embedded L-Z-source inverter (EL-ZSI) and a coupled inductor L-Z source inverter (CL-ZSI). The proposed topologies offer a high voltage gain with a reduced passive component count and reduction in source current ripple when compared to conventional ZSI topologies. Additionally, they prevent overshoot in the dc-link voltage by suppressing heavy inrush currents. This feature reduces the transition time to reach the peak value of the dc-link voltage, and reduces the risk of component failure and overrating due to the inrush current. EL-ZSI and CL-ZSI possess all of the inherent advantages of the conventional L-ZSI topology while eliminating its drawbacks. To verify the effectiveness of the proposed topologies, MATLAB/Simulink models and scaled down laboratory prototypes were constructed. Experiments were performed at a low shoot through duty ratio of 0.1 and a modulation index as high as 0.9 to obtain a peak dc-link voltage of 53 V. This paper demonstrates the superiority of the proposed topologies over conventional ZSI topologies through a detailed comparative analysis. Moreover, experimental results verify that the proposed topologies would be advantageous for renewable energy source applications since they provide voltage gain enhancement, inrush current, dc-link voltage overshoot suppression and a reduction of the peak to peak source current ripple.

• Proceedings of the Korea Water Resources Association Conference
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• 2019.05a
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• pp.103-103
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• 2019

본 연구에서는 Terra MODIS 위성영상과 Mapping Evapotranspiration at high Resolution with Internalized Calibration (METRIC) 모형을 이용하여 2012년부터 2017년까지 한반도 전국의 증발산량을 산정하고 플럭스 타워 실측 증발산량과 비교하였다. METRIC은 전 세계에 널리 적용된 바 있는 에너지 수지 기반의 Surface Energy Balance Algorithm for Land (SEBAL) 모형의 개념과 기술을 기반으로 현열(Sensible Heat Flux) 추정 모듈을 개선한 모형이다. 본 연구에서 METRIC 모형은 기존 C#으로 개발되어 있던 SEBAL 코드에서 현열 추정 모듈을 수정하였고 연산 속도 개선을 위해 Python으로 재작성하였다. METRIC 모형의 위성 자료로 Terra MODIS 위성의 MOD13A2(16day, 1km) NDVI, MOD11A1(Daily, 1km) Land Surface Temperature (LST) 및 MCD43A3(Daily, 500m) Albedo를 구축하였으며 500m 공간해상도의 Albedo는 1000m 해상도로 resample하여 활용하였다. 기상자료는 기상청 기상관측소의 풍속, 풍속측정높이, 습도, 10분 간격 이슬점 온도, 일사량 자료를 위성 자료와 같은 공간해상도로 내삽(Interpolation)하여 구축하였다. 모형결과 검증을 위해 국내 플럭스 타워 (설마천, 청미천, 덕유산) 증발산량 관측 자료와의 결정계수(Coefficient of determination, $R^2$), RMSE(Root mean square error) relative RMSE (RMSE%), Nash-Sutcliffe efficiency (NSE) 및 IOA(Index of Agreement)를 산정하고, 기존 SEBAL 모형 결과와의 비교를 통해 본 모형의 개선점을 보이고자 한다.