• 전력전자학회:학술대회논문집
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• 전력전자학회 2012년도 전력전자학술대회 논문집
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• pp.415-416
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• 2012

본 논문에서는 저가격형 PoE(Power over Ethernet)를 위한 새로운 부하분담기법을 적용한 스위칭 전원 회로를 제안한다. 기존의 PoE 전원회로는 Ethernet 채널 당 제한된 전력용량으로 인해 보다 큰 전력이 요구될 경우 채널별 DC/DC컨버터의 출력을 서로 병렬 접속하여 사용하고 있으며 각 채널별 부하를 동일하게 분담하기 위해 부하분담 IC 및 부가회로가 추가됨에 따라 회로 구조가 복잡하고 부피가 증대되는 단점이 있다. 제안된 PoE 전원회로는 이러한 문제를 해결하기 위해 병렬 연결된 채널 간 부하분담을 별도의 부가회로 없이 일정하게 제어할 수 있다. 제안 회로의 타당성 검증을 위해 이론적 분석 및 50W 급 시작품 제작을 통한 실험결과를 제시한다.

• Journal of Nutrition and Health
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• 제34권6호
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• pp.626-636
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• 2001

To compare the effect of three kinds of n-3 fatty acids-eicosapentaenoic acid(EPA), docosahexaenoic acid(DHA) and perilla oil (PO)-on serum and liver lipid levels and fatty acid composition of liver phospholipid(PL) at low fat level(5%, w/w), 4-weeks old Sprague-Dawley rats were fed with one of five different oil diets for 4 weeks. Beef tallow(BT) and corn oil(CO) was used as control for sturated or n-6 fatty acid respectively. Se겨m concentrations of cholesterol(TC) and phospholipid(PL) were lower in PO DHA and EPA groups than in BT and CO groups. HDL-cholesterol levels were higher in CO and PO groups than in EPA, DHA and BT groups. Liver PL concentrations were higher in DHA and EPA groups than in CO, PO and BT groups, but liver TC and heal PL and TC concentrations did not show any significant difference among groups. Hepatic fatty acid composition of phosphatidylcholine (PC) and phosphatidylethanolamine (PE), two major phospholipids in liver, reflected their dietary fatty acid composition. In PC and PE, total percentage own-6 series was higher in CO group than in any other groups, and that own-3 series was higher in DHA and PO groups than in EPA, CO and BT groups. Moreover, the ratio of 20 : 4/18 : 2 was lower in PO and DHA groups than in EPA, CO and BT groups. On the contrary, the percentage of C22 : 6 was lower in EPA, CO and BT groups than in PO and DHA groups. These results revealed that n-3 series(EPA, DHA and PO) were more effective in lowering um lipids than n-6 fatty acids or saturated fatty acid. Based on the results of fatty acid composition of hepatic phospholipid, we suggest that the dietary effect of PO and DHA on antiatherogenic characteristics seems to be similar extent. In addition, the effect of EPA might not be significantly different from that of BT or CO in the view of eicosanoids production from the precursor fatty acid. These difference of hepatic fatty acid composition might come from other characteristics of dietary oil as well as the type of unsaturation, not from the carbon chain length or the degree of unsaturation of n-3 fatty acid.

• Journal of Nutrition and Health
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• 제25권5호
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• pp.351-359
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• 1992

This study was conducted to compare the effects of perilla oil or corn oil on lipid peroxidation and eicosanoid productions which are associated with the promotion of carcinogenesis. in liver or blood in rats. Male Sprague-Dawley8 weaning rats were fed on semisynthetic diets containing 15%(w/w) beef fat(BF). corn oil(CO) or perilla oil(PO) Three weeks after the half of rats in each diet group were injected with a single dose of 50mg 2-acetylaminofluorene (AAF)/Kg BW hepatocarcinogen intraperitoneally 3 times at 2-day interval and all of the rats were sacrificed after 8 weeks from the first injection. The rats fed on different dietary fats without 2-AAF treatment had not different MDA produc-tion and conjugated diene content in liver microsome. CO+AAf group had significantly higher conjugated diene content than BF+AAF and PO+AAF groups. and lower glucose-6-phospha-tase activity than BF+AAF group But PO+AAF had similar conjugated diene content to BF+AAF group and significantly lower MDA production than BF+AAF and CO+AAF groups. The hepatic mocrosomal lipid peroxidation was slightly greater in CO group than in PO group though perilla oil(P/S=9.67) has much more polyunsaturated fatty acids than corn oil(P/S=2.92) PG E2 level in liver and TX B2 level in plasma were significantly higher in CO group than in BF and PO groups. TX B2 level was lowered in CO and BF groups by 2-AAF treatment. These results reach to the contclousion than the type of dietary fatty acid as well as the P/S ratio has effect on hepatic microsomal lipid peroxidation and eicosanoid production and perilla oil or linolenic acid(n3) might be less effective on lipid peroxidation or PG E2 and TX B2 mediated tumor promotion than corn oil or linoleic acid(n6).

• 한국결정학회지
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• 제11권3호
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• pp.162-166
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• 2000

KD₂PO₄ single crystals were grown from D₂O with reagent KH₂PO₄ and the crystal structure was determined by X-ray and neutron diffraction methods. The crystals are tetragonal at room temperature, I42d, with lattice parameters of a=7.4633(7), c=6.9785(5) Å and Z=4. Intensity data were collected on an Enraf-nonius CAD4 diffractometer with a graphite monochromated MoK/sub α/ radiation (λ=0.7107Å) and on the neutron four circle single crystal diffractometer with Ge(331) monochromated neutron beam (λ=0.997Å). The structure was refined by full-matrix least-square to final R and wR values of 0.030 and 0.072, respectively, for 204 observed reflections with I>2σ(I) by X-ray diffraction and to final R=0.041 and wR=0.096 for 144 observed relfecdtions by neutron diffraction. The O…O distance of 2.516(4)Å obtained by X-ray diffraction is the same as that of 2.515(4)Å by neutron diffraction. On the other hand, the O-D/H distance of 0.84(4)Å by X-ray diffraction is considerably shorter than 1.029(7) Åby neutron diffraction. Hydrogen and deuterium can be readily distinguished by neutrons. In this crystal 66% of H-positions were substituted by D and the rest 34% occupied by H. The phase transition temperature of DKDP obtained with deuteration levels is f193K. This value agrees fairly well with the result of DSC measurement. The nuclear density distribution by neutron diffraction provides an observation of the disordered state of D/H in KD₂PO₄ at room temperature.

• 한국융합학회논문지
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• 제8권6호
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• pp.9-16
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• 2017

Li-Po 에너지 밀도의 기술적 진보의 한계로 회전익 무인항공기의 비행시간은 제한적이기 때문에, 연구원들은 회전익 무인항공기의 완전한 자율 임무 수행을 위하여 우회 해결책을 찾고 있다. 몇 가지 후보 해결책들 중, 자동 무선 충전이 가장 가능성 있고 현실적인 후보이며, 본 논문에서는 자동 무선 충전의 주요 기술인 자동 착륙 전략에 초점을 맞추고 있다. MATLAB/Simulink를 기반으로 Li-Po 배터리팩 시뮬레이터를 포함한 회전익 무인항공기 비행 시뮬레이터를 개발하였으며, 이를 통해 비행 상태 및 배터리팩 상태를 분석하였다. 이륙할 때 1,647 W의 최대 모터 출력이 발생하였고, 이때 셀 전압은 최소 3.39 V까지 감소하였다. 이는 22 Ah를 지니고 12S1P로 연결된 2개의 배터리팩이 자동 착륙 임무수행에 적합하다는 것을 나타낸다.

• 환경정책연구
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• 제6권1호
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• pp.1-40
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• 2007

본 연구에서는 생물다양성 보전에 있어 보호지역의 중요성을 인식하고, 2004년 생물다양성협약 제7차 당사국회의에서 채택한 보호지역 실행프로그램의 이행상황을 진단하고 향후 개선방향을 모색하고자 하였다. 이를 위해 먼저 국내 보호지역 지정 및 관리 현황을 고찰하였으며, 보호지역 실행프로그램에서 제시하고 있는 9개 주제별로 목적과 활동내용을 국가적 맥락에서 검토하였다. 그리고 구체적인 이행사항 파악을 위해 우리나라 대표적 보호지역이라고 할 수 있는 국립공원의 관리 현황을 사례로 이행 진행사항을 비교 분석하였다. 먼저 국내 보호지역 지정 및 관리 현황을 고찰한 결과 우리나라는 1960년대 이후 보호지역을 지정하기 시작하였으며, 대략 14개 유형의 1,119개소로 층 면적은 개략적인 수치이지만 대략 $15,621km^2$에 이르는 것으로 나타났다. 보호지역 실행프로그램에서는 보호지역과 관련된 다양한 이행활동(4개 요소, 9개 주제, 16개 목적, 92개 활동)을 제시하고 있는데, 우리나라의 이행상황을 살펴본 결과 개별 보호지역의 계획 및 관리 분야, 보호지역에 대한 위협 방지와 완화, 보호지역 시스템 설정 분야는 상당부분 실행프로그램을 이행하였거나 진행 중인 것으로 나타났으며, 보호지역의 사회적 혜택 개선, 재정적 지속가능성, 관리표준과 관리효과성 평가 분야가 상대적으로 이행이 미흡한 것으로 나타났다. 특히 보호지역 실행프로그램의 이행활동을 시간제한 관점에서 보면 생물다양성과 생태계 보전을 위한 격차분석, 생태계 서비스의 가치에 대한 연구, 관리효과성 평가방법 및 기준개발 등이 시급한 것으로 판단된다. 본 연구 결과는 우리나라 보호지역의 지정 및 관리 현황에 대한 체계적 이해를 도울 수 있을 것이며, 향후 생물다양성협약 국가보고서와 보호지역 실행프로그램 이행보고서 작성을 위한 기초자료로 활용될 수 있을 것이다. 향후 보호지역 실행프로그램의 생물다양성 손실률의 획기적 감소라는 목표를 달성하기 위해서는, 국가차원에서의 체계적인 접근과 보호지역 관련 유관기관들이 수립한 여러 계획들의 충실한 수행이 수반되어야 할 것이다.

• Journal of Nutrition and Health
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• 제27권6호
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• pp.537-551
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• 1994

The dietry effects of marine n-3, plant n-3 and plant n-6 fatty acid on serum lipids levels, liver phospholipid fatty acid composition in rat were investigated. Four groups of male Sprague-Dawley rats, 30 weeks old, were fed on one of 4 different experimental diets for 4 weeks. The diets were composed of 15% fat(w/w) of either concentrated EPA oil(20:5, n-3 : 65%), fish oil(20:5, n-3 : 19%, 22:6, n-3 : 18%), perilla oil(18:3, n-3 : 60%) or corn oil(18:2, n-6 : 49%). Blood was initially taken before experimental feeding and also taken after 2 weeks and 4 weeks feeding the diet respectively and then examined for the levels of serum lipids. Rats were sacrificed at 4 weeks after the diet for the analysis of liver phospholipid fatty acid. EPA feeding remarkably decreased the serum levels of triglyceride, total cholesterol, HDL-cholesterol and total phospholipid than any other oil feeding. Fish oil feeding decreased serum HDL-cholesterol level comparable to the effect of EPA feeding and decreased total cholesterol and phospholipid less than but close to the effect of EPA feeding. Perilla oil feeding did not change serum levels of triglyceride and phospholipid, but it decreased serum total cholesterol a lot and HDL-cholesterol a little. Corn oil feeding did not affect triglyceride and total cholesterol while it increased serum level of HDL-cholesterol and total phospholipid. Serum HDL-cholesterol level was increased only in corn oil group. But contrary to the result of serum total phospholipid, liver phospholipid level found to be higher in fish oil and EPA groups than in perilla oil and corn groups. The fatty acid composition of liver phospholipid, phosphatidylcholine(PC) and phosphatidyl ethanolamine(PE) turned out to be affected by dietary fatty acid. 18:2 of liver PC was the lowest in FO group following CO group. The ratio of 20:4/18:2 was lower in PO group than in EPA group in consequence of higher 18:2 and lower 20:4 in PO group and vise versa in EPA group. In the liver PC and PE, similar trends in the ratios of n-6/n-3 and 20:4/18 were found showing higher ratios with CO and EPA group over FO and PO group. EPA group showed the lowest level of 20:5 and lower level of 20:6 than group. Fish oil was more efficient than EPA oil and PO in lowering the ratio of n-6/n-3 in consequence of the highest 22:6, and the lowest 18:2 in liver phospholipid. But PO lowers the ratio or 20:4/18 more than FO. In conclusion, EPA oil was more effective in lowering serum lipids than FO and PO. Reviewing the dietary effect of fatty acid on eicosanoids composition in rats, it is considered that more possibility was with FO than PO in the effectiveness of atherosclerosis prevention and more with PO than with EPA oil. It was also found that FO showed more effective than EPA oil for atherosclerosis prevention. It was hardly found that CO had any effect on lowering serum lipids and on eicosanoids composition in liver phospholipid for the prevention of atherosclerosis.

• 한국미생물·생명공학회지
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• 제25권4호
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• pp.403-407
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• 1997

Medium components for maximum activity of NAD$^{+}$-dependent formate dehydrogenase (EC 1.2.1.2; FDH) were optimized with a methanol-assimilating yeast Hansenula sp. MS-364, preserved by our laboratory. The maximum activity of the enzyme was obtained when the strain was cultivated at 30$circ$C for 24 hours in a medium containing methanol 3%(v/v), yeast extract 0.8%(w/v), K$_{2}$HPO$_{4}$, 0.1%(w/v), KH$_{2}$PO$_{4}$ 0.1%(W/V), MgSO$_{4}$, 7H$_{2}$O 0.05%(w/v), and the pH of the culture broth was adjusted at 5.0.

• 한국미생물·생명공학회지
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• 제21권5호
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• pp.435-439
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• 1993

For the overproduction of glutathione, Candida sp. mutant was isolated by the treatment with U.V. light. The highest glutathione production of Candida sp. mutant was obtained after shaking culture for 48 hours in the cullture medium containing glucose 1.5%(w/v), yeast extract 4.0% (w/v), KH2PO4 0.04%(w/v), biotin 5 ng/ml, and L-cysteine 0.04%(w/v). The optimal pH and temperature for the glutathione production were pH 6.0 and 25C, respectively.

• 생명과학회지
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• 제22권2호
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• pp.200-208
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• 2012

본 연구에서는 균사의 액체 배양 특성 조사를 위하여 꽃송이버섯 균주 KGFS08과 KFRI746를 선발하였다. 균사 생장을 위한 우수 배지는 KTM 배지로 조사되었으며, 탄소원과 질소원은 각각 3% (w/v) starch와 0.3% (w/v) tryptone, 비타민은 folic acid로 나타났다. 따라서 액체 배양 최적 조건은 STK 배지[3% (w/v) starch, 0.3% (w/v) tryptone, 0.1% (w/v) $KH_2PO_4$, 0.1% (w/v) folic acid], pH는 4.0~5.0으로 확인되었다.