• Natural Product Sciences
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• v.6 no.3
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• pp.131-134
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• 2000

The methanol, dichloromethane, petroleum ether, 90% methanol and 1-butanol fractions of 40 Malaysian medicinal plants belonging to 25 families were tested for brine shrimp lethality. Various parts and fractions of eight (20%) plants, viz. Annona muricata, Cerbera odollam. Calophyllum inophyllum, Entada phaseoloides, Pithecellobium jiringa, Crotolaria retusa, Morinda elliptica and Sellaginella willdenovii showed very strong toxicity $(LC_{50}:$<$100\;ppm)$. The methanol extract of the seed of Calophyllum inophyllum showed exceptionally toxic activity $(LC_{50}:$<$5\;ppm)$.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.533-534
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• 2008

This paper presents a multi-phase ring VCO for low-cost, low-power GPS receiver. In the RF band used in GPS, L1 band is now in commercial-use and L2,L5 are predicting to be commercial-use soon. Thus Wide band PLL and Cost-effective IC solutions are required for future multi-band GPS receiver that received three types band at once. A new PLL architecture for multi-band GPS application is proposed. Ring VCO is even smaller than LC-VCO and a good alternative for low-cost solution. Proposed multi-phase ring VCO offers wide frequency range covering L1, L2, and L5 band, 20% reduction of area, 23% reduction of PLL power and can generate I/Q without extra I/Q generator.

• Journal of Electrical Engineering and Technology
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• v.13 no.1
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• pp.220-225
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• 2018

A class E power oscillator is demonstrated for 6.78-MHz wireless power transfer system. The oscillator is designed with a class E power amplifier to use an LC feedback network with a high-Q inductor between the input and the output. Multiple capacitors are used to minimize the variation of the oscillation frequency by capacitance tolerance. The gate and drain bias voltages with opposite characteristics to make the frequency shift of the oscillator are connected in a resistance distribution circuit located at the output of the low drop-out regulator and supplied bias voltages for class E operation. The measured output of the class E power oscillator, realized using the co-simulation, shows 9.2 W transmitted power, 6.98 MHz frequency and 86.5% transmission efficiency at the condition with 20 V $V_{DS}$ and 2.4 V $V_{GS}$.

• Journal of Food Hygiene and Safety
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• v.33 no.1
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• pp.58-64
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• 2018

An analytical method for the determination of cephalexin (CEX) in bovine tissues (muscle, liver, kidney and fat tissues) was developed and validated using liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). Tissue samples were extracted by the liquid-liquid extraction based on 5% trichloroacetic acid (TCA). The chromatographic separation was achieved on a reverse phase $C_{18}$ column with gradient elution using a mobile phase of 20 mM hexafluroacetylacetone (HFAC)/50% acetonitrile (40:60). The procedure was validated according to the Ministry of Food and Drug Safety guideline determining accuracy, precision, and limit of detection. Mean recoveries of CEX from spiked edible tissues ($6{\sim}1,500{\mu}g/kg$) were 83.9~106.8%, and the relative standard deviation was between 2.3 and 14.8%. Linearities were obtained with the correlation coefficient ($r^2$) of > 0.999. Limit of detection and limit of quantification for the investigated CEX were 2~10 and $6{\sim}30{\mu}g/kg$, respectively. This method was reliable, sensitive, economical and suitable for routine monitoring of CEX residues in bovine edible tissues.

• Proceedings of the Korean Journal of Food and Nutrition Conference
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• 2001.12a
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• pp.124-124
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• 2001

난소화성전분(resistant starch, RS)는 건강한 사람의 소장에서 흡수되지 않는 전분과 분해된 전분의 산물을 총칭하는데. 대장에서 발효와 미생물성장, 식후 혈당, 변부피, 장통과시간, 식품의 열량가 등에 영향을 미치므로 생리적인 이점을 갖는다. 본 연구에서는 고지방식이와 콜레스테롤을 섭취란 흰쥐에서 제조과정이 다른 RS의 섭취가 저 열량원으로서 체중감소나 혈액내 지방성분을 낮추는 효과가 있는지를 알아보는 것을 목적으로 하였다. 연구방법으로 실험동물은 생후 4주된 Sprague-Dawl ey계 수컷 흰쥐로, 지방을 식이 무게의 20%, 콜레스테롤이 식이 무게의 1%로 첨가 된 고지방식이로 6주를 사육시켜 비만과 고콜레스테롤증을 유발시켰다. 고콜레스테롤이 유발된 실험동물은 섭취하는 전분의 형태가 다른 실험식이로 4주간을 더 사육하였고 사육기간이 끝난 실험동물들은 희생하여 생화학적인 실험- 혈액과 간의 총지방양, 중성지방양, 콜레스테롤양을 측정하였고, 면역능력으로 비장세포 증식, 혈장내 IgG, $C_3$양을 측정하였고. 혈장내 leptin 양을 측정하였다. 실험결과는 체중과 체내 저장지방무게가 난소화성전분 혼합군(RSNE)에서 유의적으로 감소하였다. 혈장내 지방성분을 보면, 총 지방의 경우 고지방대조군(HC)이 저지방 대조군(LC)에 비래 유의적으로 높았으며, RS를 섭취하면 유의적으로 낮아지는 경향을 보여 저지방을 섭취한 LC군에 비해서 낮은 수치를 나타내고 있다. 혈장 중성지방은 저지방 즉 고 탄수화물식이를 섭취하는 LC군이 유의적으로 높았으며 고지방을 섭취하는 경우는 실험군에 차이가 없었다. 혈장 총 콜레스테롤은 LC군에 비해 고지방과 콜레스테롤을 섭취하는 HC군이 유의적으로 높았으며. RSNE군에서는 유의적인 감소를 보였다. HDL-콜레스테롤에서는 실험군간에 차이가 없었다. 간내 총지방과 콜레스테롤량, 중성지방량은 LC군이 다른 군에 비해 유의적으로 적었으며 고지방섭취군들은 섭취하는 전분의 종류에 따른 차이가 나타나지 않았다. 면역능력을담당하는 체내 기관인 비장세포의 중식능력은 실험군간에 유의적인 차이가 없으나 혈장의 Ig G 양은 RSNE군이 유의적으로 높고, $C_3$ 양은 난소화성 전분 추출군(RSEX)에서 유의적으로 높게 나타났다. 혈장에서의 leptin 농도는 고지방 대조군인 HC군이 유의적으로 높았으며, RSNE군이 LC군과 같이 유의적으로 낮았다. 결론으로 난소화성 전분(RS)를 식이무게의 10%로 첨가하는 수준에서 순수한 RS보다는 RS제조과정 중 순수한 RS를 분리하기 전 단계인 RS를 포함한 전분이 체중감소, 체내 저장지방감소, 혈액 내 콜레스테롤을 저하시키는 효과를 보였다. 그러므로 RS의 섭취는 섭취형태에 따라 저 열량원으로, 혈액 내 지방성분을 낮추는 효과를 가진 기능성 식품소재로 사용될 수 있을 것이다.

• Journal of Dairy Science and Biotechnology
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• v.33 no.1
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• pp.17-25
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• 2015

The present study was carried out to evaluate the preparation of the fermented milks with rice bran and to prove that the bacteria used are necessary for providing amino acids in this process. The rice bran on fermented milk with Streptococcus thermophilus (ST-body1) and Lactobacillus casei (LC-10). The fermentation limit was set until acidimetry score reaches 1. There are reports of titratable acidity, pH, viable cell count and amounts of organic acids affecting amino acid production about physical and chemical analysis measured using HPLC. Finally, sensory test was surveyed. In this study, the rate of acidification was higher in the fermented milk with rice bran than in the common fermented milk. In case of the number of cells was $1.0{\times}10^8CFU/mL$ in group. The lactic acid and citric acid content in yogurts prepared with rice bran using Streptococcus thermophilus (ST-body1) and Lactobacillus casei (LC-10) was higher than that in the control yogurt. Amino acids derived by rice bran were effected in fermentation for each bacteria's necessary amino acid production, and it made bacteria growth larger. From the physical test of the fermented milk with rice bran, flavor, texture, sweetness, overall taste of the fermented milk of Streptococcus thermophilus (ST-body1) were found to be much better than those of the other groups. The results obtained for the fermented milk prepared with rice bran using Streptococcus thermophilus (ST-body1) are significant.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.42 no.4 s.334
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• pp.61-68
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• 2005

A chip, which can fast encoder the audio data to AAC (Advanced Audio Coding) LC(Low Complexity) that is MPEG-2 audio standard, has been designed on the basis of a 32 bits DSP core and fabricated with 0.25um CMOS technology. At first, the various optimization methods for implementing the algerian are devised to reduce the memory size and calculation cycles. FFT(Fast Fourier Transform) hardware block is added to the DSP core to get the more reduction of the calculation cycles. The chips has the size of $7.20\times7.20 mm^2$ and about 830,000 equivalent gates, can carry out AAC encoding under 70MIPS(Million Instructions per Second).

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.5
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• pp.874-881
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• 1997

In order to estimate toxicity of copper, radmium and chromium on survival, growth and oxygen consumption of the estuarine mysid, Neomysis awatschensis, adult and juvenile, the experiments were conducted by renewal bioassay method at $20{\pm}1^{\circ}C\;and\;20{\pm}1\%_{\circ}$ salinity. The $96hr-LC_{50}$ of the mysid exposed to cadmium, copper and chromium was 20.2, 11.3 and $670.4\;{\mu}g/\ell$ in adut and 3.4, 1.9 and $49.4\;{\mu}g/\ell$ in juvenile, respectively, and were ranked in order of toxicity : copper >cadmium >chromium. Survival rates of the mysid exposed to the sublethal concentrations of heavy metals for 40 days were significantly affected by cadmium $\geq1.0\;{\mu}g/\ell$ and copper $\geq0.6\;{\mu}g/\ell$ concentrations. The growth rate of the mysid exposed to $cadmium\geq2.0\;{\mu}g\ell$ and copper $\geq1.2\;{\mu}g/\ell$ concentrations were significantly reduced than that exposed to normal condition, but there was no affect on intermoult period. Oxygen consumption rate of the mysid exposed to heavy metals was significantly reduced with increasing heavy metals concentrations. The results of the present study led us to conclude that concentrations levels cadmium$\geq1.0\;{\mu}g\ell$ and copper $\geq0.6\;{\mu}g\ell$ of the estuarine could markedly affect the distribution and population of the mysid by reduced survival, growth and oxygen consumption rate.

• Journal of the Korean Institute of Gas
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• v.17 no.4
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• pp.18-25
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• 2013

It may occur health hazards or death by suffocation or acute poisoning in case of oxygen deficiency in ambient or exposure to harmful gas. As a part of accident prevention, we studied the change of activity and lethal dose by changing the concentration of several hazardous gas with inhalation exposure chamber and laboratory animals. We investigated the lethality and motility change during either the 4 hrs whole body exposure to oxygen, nitrogen, toluene, $H_2S$, CO and 48 recovery. As results, it is estimated that 5% oxygen concentration as lethal concentration and 5.5% as $LC_{50}$ (rat, 4 hrs) with statistics for dose-response. The results of lethality in oxygen deficient condition (approximately 6%), the lethalities were 40%, 20% with 20 ppm $H_2S$, 600 ppm CO respectively, and was not increased the lethality with 8% CO. Thus, it was confirmed that the $H_2S$, CO had influence to lethal dose, while toluene had low fluence.

• Horticultural Science & Technology
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• v.30 no.1
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• pp.34-41
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• 2012

The study was conducted in a glasshouse to examine the possibility of producing paprika plug seedlings in a newly developed inert phenolic foam growing medium. Plug seedlings of 'Fascinato' paprika were grown in five media, Grodan rockwool (Grodan Co. Ltd., Denmark), UR rockwool (UR Co. Ltd., Korea), phenolic foam LC (Smithers Oasis Korea Co. Ltd., Korea), phenolic foam RC, and phenolic foam 3813-4 all in a pellet type. Seeds were germinated in a growth chamber ($25^{\circ}C$, 90% RH, dark) for 4-5 days and then seedlings were grown in a glasshouse with nutrient solution supplied by an overhead irrigation system. Seedling growths were measured 20 days after sowing. The medium pH was the highest in the Grodan rockwool, and medium EC was the highest in phenolic foam 3813-4, although no nutritional excess disorders were observed. Germination rates of paprika were higher than 90% in all the media. Plant height, stem diameter, T/R ratio, leaf area, and chlorophyll showed a similar to those in the rockwool medium. Number of leaves, length of the longest root and dry weights of shoot were not significantly different among treatments. Overall, phenolic foam LC and RC produced seedlings with a similar growth as the rockwool medium. The results obtained suggest that rockwool can be replaced with a new material such as phenolic foam in the commercial scale production of plug seedlings of 'Fascinato' paprika.