• Korean Journal of Environmental Agriculture
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• v.16 no.4
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• pp.399-403
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• 1997

Changes of nutrient material and natural supplies by sediment of irrigation water into 1.0ha of paddy field during the rice cultivation were investigated. TSS of the sediment contained irrigation water ranged 52.9${\sim}$125.6mg/L and content of organic matter showed 1.89${\sim}$2.33%. Content of T-N, $NH_4-N$ and $NO_3-N$ were 623.5${\sim}$1775.2, 22.9${\sim}$75.8 and 10.2${\sim}$72.1mg/kg respectively. Content of T-P and ortho-P were 186.7${\sim}$375.7 and 12.4${\sim}$38.9mg/kg respectively. The content of exchangeable canons, $Ca^{++},\;Mg^{++}\;Na^+\;and\;K^+$ were 435.3${\sim}$737.5, 127.3${\sim}$204.2, 36.6${\sim}$94.9 and 105.6${\sim}$232.9mg/kg respectively. Total content of heavy metals were 13.4 of Pb, 0.6 of Cd, 8.2 of Ni, 12.1 of Cu, 29.8 of Zn and 19.7mg/kg of Cr. During the period of rice cultivation, when supplied 4,250m^3 of an irrigation water into 1.0ha of paddy field, natural supplied 346.01kg of sediment, 7.11kg of organic matter, 0.50kg of T-N, 0.02㎏ of NH_4-N, 0.01kg of NO_3-N, 0.08kg of T-P and 0.01㎏ of Ortho-P. Also exchangeable $Ca^{++},\;Mg^{++}\;Na^+\;and\;K^+$ were supplied 0.21, 0.06, 0.02 and 0.06kg respectively. Loaded of the total heavy metal showed natural background level.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.9
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• pp.1166-1171
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• 2006

This study was performed to investigate the effect of silk protein hydrolysates on blood glucose in diabetic mice (C57BL/KsJ db/db). The silk protein hydrolysates hydrolyzed by protease contains 87.52% of peptides of which molecular weight was below 2,000 dalton. The content of free amino acids was 14.80 g/100 g silk protein hydrolysates and major free amino acids were Pro, Thr, Arg and Ala. Silk protein hydrolysates were administered to the animals for 9 weeks at doses of 0.2, 0.5% and 0.8% solution. The body weight increase in the 0.5 and 0.8% fed groups were higher than control group. Food and water intake in the silk protein hydrolysates fed groups were lower than control group. The weight of liver was not different among groups, while the weight of kidney in control group was higher than silk protein hydrolysates fed groups. The blood glucose level in silk protein hydrolysates fed groups was lower than control group. In the glucose tolerance test, the blood glucose level in control group was the highest at 15 minutes after glucose injection while those in silk protein hydrolysates fed groups were the highest at 30 minutes. Results in this study suggest that silk protein hydrolysates show hypoglycemic effect in C57BL/KsJ db/db mice.

• Journal of Korea Water Resources Association
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• v.54 no.9
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• pp.719-730
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• 2021

The objective of this study is to develop the water quality and aquatic ecosystem model for Andong lake using SWAT-WET (Soil and Water Assessment Tool-Water Ecosystem Tool) and to evaluate the applicability of WET. To quantify the pollutants load flowing into Andong lake, a watershed model of SWAT was constructed for Andong Dam basin (1,584 km²). The calibration results for Dam inflow and water quality loads (SS, T-N, T-P) were analyzed that average R² was more than 0.76, 0.69, 0.84, and 0.60 respectively. The calibrated SWAT results of streamflow and nutrients concentration was used into WET input data. WET was calibrated and validated for water temperature, dissolved oxygen, and water quality concentration (T-N, T-P) of Andong lake. The WET calibrated results was analyzed that PBIAS was +19%, -13%, +4%, and +26.5% respectively and showed that it was simulated to a significant level compared with the observation data. The observed dry weight (gDW/m²) of zoobenthos was less than 0.5, but the average value of simulation was analyzed to be 0.8, which is because the WET model considers zoobenthos with a broader concept. Although accurate calibration is difficult due to the lack of observed data, SWAT-WET can analyze the effects of environmental change in the upstream watershed on the lake based on long-term simulation based on watershed model. Therefore, the results of this study can be used as basic data for managing the aquatic environment of Andong lake.

• Journal of the Korean Institute of Gas
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• v.24 no.6
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• pp.1-10
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• 2020

Reactivity controlled compression ignition (RCCI) combustion is one of dual-fuel combustion systems which can be constructed by early diesel injection during the compression stroke to improve premixing between diesel and air. As a result, RCCI combustion promises low nitrogen oxides (NOx) and smoke emissions comparing to those of general dual-fuel combustion. For this combustion system, to meet the intensified emission regulations without emission after-treatment systems, exhaust gas recirculation (EGR) is necessary to reduce combustion temperature with lean premixed mixture condition. However, since EGR is supplied from the front of turbocharger system, intake pressure and the amount of fresh air supplementation are decreased as increasing EGR rate. For this reason, the effect of various EGR rates on the brake power and thermal efficiency of natural gas/diesel RCCI combustion under two different operating conditions in a 6 L compression ignition engine. Varying EGR rate would influence on the combustion characteristic and boosting condition simultaneously. For the 1,200/29 kW and 1,800 rpm/(lower than) 90 kW conditions, NOx and smoke emissions were controlled lower than the emission regulation of 'Tier-4 final' and the maximum in-cylinder pressure was 160 bar for the indurance of engine system. The results showed that under 1,200 rpm/29 kW condition, there were no changes in brake power and thermal efficiency. On the other hand, under 1,800 rpm condition, brake power and thermal efficieny were decreased from 90 to 65 kW and from 37 to 33 % respectively, because of deceasing intake pressure (from 2.3 to 1.8 bar). Therefore, it is better to supply EGR from the rear of compressor, i.e. low pressure EGR (LP-EGR) system, comparing to high pressure EGR (HP-EGR) for the improvement of RCCI power and thermal efficiency.

• Journal of Distribution Research
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• v.16 no.2
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• pp.1-24
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• 2011

1. Introduction: Contrast to the offline purchasing environment, online store cannot offer the sense of touch or direct visual information of its product to the consumers. So the builder of the online shopping mall should provide more concrete and detailed product information(Kim 2008), and Alba (1997) also predicted that the quality of the offered information is determined by the post-purchase consumer satisfaction. In practice, many fashion and apparel online shopping malls offer the picture information with the product on the real person model to enhance the usefulness of product information. On the other virtual product experience has been suggested to the ways of overcoming the online consumers' limited perceptual capability (Jiang & Benbasat 2005). However, the adoption and the facilitation of the virtual reality tools requires high investment and technical specialty compared to the text/picture product information offerings (Shaffer 2006). This could make the entry barrier to the online shopping to the small retailers and sometimes it could be demanding high level of consumers' perceptual efforts. So the expensive technological solution could affects negatively to the consumer decision making processes. Nevertheless, most of the previous research on the online product information provision suggests the VR be the more effective tools. 2. Research Model and Hypothesis: Presented in