• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.10
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• pp.4069-4074
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• 2010

Phase change of calcium carbontae crystals in crystallization of precipitated calcium carbonate was researched by adding additives such as ethylenediaminetetraacetic acid(EDTA), diethylenetriaminepentaacetic acid(DTPA), citric acid(CIT) and pyromellitic amid(PMA). At low temperature $20^{\circ}C$, calcite crystal was made. At high temperature $80^{\circ}C$, aragonite crystal was made without additives. At middle temperature $40^{\circ}C$ and $60^{\circ}C$, Aragonite crystal also made by adding EDTA, DTPA. The crystal growth of Aragonite was retarded by the presence of CIT, PMA and the single phase of calcite was made. It was found that additives were important factors to make the single phase of calcium carbonate.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.4 no.3
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• pp.697-703
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• 2000

As device dimensions are lastly scaled down, impact ionization(I.I.) events are very important to analyze hot carrier transport in high energy region, and the exact model of impact ionization is demanded on device simulation. We calculate full band model by empirical pseudopotential method and the impact ionization rate is derived from modified Keldysh formula. We calculate impact ionization coefficients by full band Monte Carlo simulator to investigate temperature dependent characteristics of impact ionization for GaAs as a function of field. Resultly impact ionization coefficients are in good agreement with experimental values at look. We how energy is increasing along increasing the field, while energy is decreasing along increasing the temperature since the phonon scattering rates for emission mode are very high at high temperature. The logarithmic fitting function of impact ionization coefficients is described as a second orders function of temperature and field. The residuals of the logarithmic fitting function are mostly within 5%. We Dow, therefore, the logarithm of impact ionization coefficients has quadratic dependence on temperature, and we can save time of calculating the temperature dependent impact ionization coefncients as a function of field.

• Journal of Nutrition and Health
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• v.36 no.8
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• pp.793-800
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• 2003

This study was conducted to investigate the antioxidative effects of Paeonia lactiflora (PL) seeds on antioxidative defense system and lipid peroxidation of liver in rats fed high-cholesterol diet. Sprague-Dawley male rats weighing 100 $\pm$10g were randomly assigned into five experimental groups fed 0.5% cholesterol ; HC group which was not supplemented PL seeds extract, 0.1% methanol extract diet group (MP1 group), 0.2% methanol extract diet group (MP2 group), 0.05% ether-souble fraction diet group (EP1 group) and 0.1 % ether-souble fraction diet group (EP2 group). Experimental diets were fed ad libitum to the rats for 3 weeks. The activity of hepatic superoxide dismutase (SOD) was not significantly different among all the high cholesterol diet groups. The hepatic glutathione peroxidase (GSHpx) activity in MP2 group was increased to 27% compared to HC group. The activity of hepatic catalase (CAT) was not significantly different among the all high cholesterol diet groups. The hepatic glutathione S-transferase (GST) activity in the EP1 and EP2 groups were increased to 12% and 13%, respectively, as compared to HC group. The levels of hepatic TBARS in the MP1, MP2, EP1 and EP2 groups were reduced by 18%, 21%, 20% and 23%, respectively, as compared with HC group. The contents of lipofuscin in liver was not significantly different among all the experimental groups. The results indicated that PL seeds extract may be reduced oxidative damage by activating antioxidative defense system of hepatic in rats fed high-cholesterol diets. (Korean J Nutrition 36(8): 793∼800, 2003)

• Journal of Korean Society of Environmental Engineers
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• v.33 no.4
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• pp.275-280
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• 2011

In the present work, the aerobic particle's characteristics were enhanced. A polymer was used to make aerobic granular sludge in short period of time. And operation parameters were calculated for organic matter removal in domestic wastewater using a sequencing batch reactor (SBR). The experiment for sewage (Influent concentration of 63~72 mg COD/L) by using mature aerobic granular sludge showed the organic matter removal rate k and oxygen utilization coefficient a', b' were $10.161d^{-1}$ and 0.87 mg $O_2/mg$ $COD_r$, 0.11 mg $O_2/mg$ MLVSS d respectively. Therefore, it was more effective than K value $5{\sim}8d^{-1}$ of conventional activated sludge process. The sludge synthetic value and sludge auto-oxydation value were 0.45 mg VSS/mg $COD_r$ and 0.05 mg VSS/mg MLVSS d respectively. Consequently, mortality rates of microorganisms was lower than conventional activated sludge process.

• Proceedings of the Korea Water Resources Association Conference
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• 2008.05a
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• pp.319-323
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• 2008

본 연구는 인접한 저수지 간의 연계운영을 통해 홍수조절능력을 제고시키기 위한 저수용량 공유기법 개발의 일환으로서 안동댐과 임하댐의 병렬저수지 시스템을 연구대상유역으로 선정하였다. 홍수조절에 의한 병렬저수지의 연계운영기법으로서 홍수시 임하댐의 저수량을 안동댐으로 전환시켜 임하댐의 홍수조절능력을 제고시키고 안동댐의 저수량을 확보하여 용수공급능력을 제고시킬 수 있는 방법을 연구하였다. 임하댐의 유입량 중 안동댐으로 전환되는 유량비를 최적화계수 a로 두고 재현기간별로 유량전환비를 산정한 결과 최적화계수로 제안한 유량전환비 a는 재현기간 T=50년일 때 $a_{50}=0.310$, T=80년일 때 $a_{80}=0.185$, T=100년일 때 $a_{100}=0.130$, T=150년일 때 $a_{150}=0.035$로 산정되었으며, T=200년일때는 유량전환에 의한 홍수조절 효과가 없음을 알 수 있었다. 이러한 계산결과는 홍수규모가 클 경우에 안동댐 저수량(위) 증가로 인하여 임하댐의 유량전환비가 감소하기 때문임을 알 수 있었으며, 그 유량전환비가 거의 0이 될 경우는 홍수규모가 재현기간 T=200년 빈도 이상에서 나타나고 있음을 알 수 있었다. 이로 인한 홍수조절효과는 임하댐의 경우 재현기간 T=50년 일 때 4.1%, T=80년일 때 2.8%, T=100년일 때 2.1% 및 T=150년일 때 0.7%로 증가한 것으로 나타났으며, 안동댐의 경우 재현기간 T=50년일 때 14.4%, T=80년일 때 8.6%, T=100년일 때 6.0% 및 T=150년일 때 1.6%로 증가한 것으로 분석되었다.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.45 no.6
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• pp.22-27
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• 2008

Analytical models for breakdown voltage and specific on-resistance of 4H-silicon carbide Schottky diodes have been derived successfully by extracting an effective ionization coefficient $\gamma$ from ionization coefficients $\alpha$ and $\beta$ for electron and hole in 4H-SiC. The breakdown voltages extracted from our analytical model are compared with experimental results. The specific on-resistance as a function of doping concentration is also compared with the ones reported previously. Good fits with the experimental results are found for the breakdown voltage within 10% in error for the doping concentration in the range of about $10^{15}{\sim}10^{18}\;cm^{-3}$. The analytical results show good agreement with the experimental data for the specific on-resistance in the range of $3{\times}10^{15}{\sim}2{\times}10^{16}\;cm^{-3}$.

• Korean Journal of Plant Tissue Culture
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• v.21 no.6
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• pp.319-326
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• 1994

For the gene tagging of Armoracia rusticana, maize controlling element Ac and Ds were introduced into A.rusticana via Agrobacterium-mediated transformation method. We established an efficient in via regeneration and transformation system for gene transfer in A. rusticana. The optimum in via regeneration condition has been obtained from leaf, petiole and root organs on modified MS medium supplemented with NAA 0.1 mg/L plus BA 1.0 mg/L for direct shooting and with free growth regulators for root induction for transformation, the leaf, petiole and root explants of A. rusticana were concultivated with Agrobacterium tumefaciens, LBA4404 which carries a binary vector pEND4K containing maize controlling element Ac or Ds, respectively: Selections were performed in the shoot induction medium supplemented with 100 mg/L kanamycin, and 500 mg/L carbenicillin transformation frequency showed about 8 to 10% in case of leaf disks. PCR md Southern blot analyses showed that the Ac and the Ds elements were integrated into the chromosome of donor plants.

• Korean Journal of Plant Tissue Culture
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• v.21 no.2
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• pp.99-103
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• 1994

The herbicide bialaphos is a potent inhibitor of glutamine synthetase in higher plants. A bialaphos resistance (bar) gene encoding for an acetyltransferase was isolated from genomic DNA of Pseudomonas syringae pv tabaci. The bar gene was ligated to the binary vector pBI121. Pistils of tobacco plane were heated with the bar gene containing plasmid DNA at various times after pollination. When the treatment was applied at 30 and 40 h after pollination, a number of transgenic plants were obtained. Premary transformation (T$_{0}$ generation) and their progenies (T$_1$T$_2$) were resistant to both bialaphos and kanamycin at a dosage lathal to untransformed control plants. Stable integration of bar gene into chromosomal DNA was proven by Southern blot analysis of genomic DNA isolated from T$_1$progenies. These results show that the bialaphos resistant plane could be obtained by treatment to pistils with the exgenous bar gene through the fertilization cycle of tobacco.o.

• The Korean Journal of Community Living Science
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• v.14 no.2
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• pp.41-47
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• 2003

To investigate the effects of hot water soluble extract from Angelicae Gigantis Radix on lipid metabolism and antioxidant defense system in rats fed hypercholesterol diet, Sprague-Dawley male rats were fed either hypercholesterol diet with water or hot water soluble extract from Angelicae Gigantis Radix. Hypercholesterol diet contained 18 % beeftallow and 5 % cholesterol. After 4 weeks of experimental periods serum and liver obtained. The level of serum lipid and the activities of GOT and GPT was measured. The level of lipid and TBARS and the activity of GSH-Px was measured also. The results obtained were: 1) Food intake in the experimental group supplied hot water soluble extract from Angelicae Gigantis Radix was low significantly. 2) In the experimental group supplied hot water soluble extract from Angelicae Gigantis Radix of serum total lipid and total cholesterol was significantly low. 3) Serum GOT activity was significantly low in the experimental group supplied hotwater soluble extract from Angelicae Gigantis Radix. There was no difference of serum GPT activity between control and experimental group supplied hot water soluble extract from angelical Gigantis Radix. 4) There was no difference of lipid composition, TBARS level and GSH-px activity in liver between control and experimental group. The result of this study indicates that the hot water soluble extract from Angelicae Gigantis Radix was effective in decreasing the food intake of the experimental animals in the hypercholesterol diet and also effective in decreasing the levels of serum total lipid, total cholesterol and GOT activity. However it was not effective to change the level of lipid, TBARS and GSH-Px activity of liver.

• Journal of Broadcast Engineering
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• v.17 no.4
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• pp.670-675
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• 2012

If the region of interest (ROI) is set within the picture of image and video and the high quality is provided in ROI compared to Non ROI, then overall subjective picture quality can be increased. ROI extracted by the color camera only increases the calculation complexity and reduces the extraction accuracy. In this paper, we use depth camera to set the ROI and calculate the object distance from camera, then propose a method that the different picture quality is controlled by depending on the distance of an object. That is, we apply a high quantization step size to the far object, but relatively a low quantization step size to the close object, so better picture quality can be provided. Simulation results show that applying the differential quantization step size to the distance of objects by the proposed method can improve the subjective picture quality.