• 한국미생물·생명공학회지
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• 제18권3호
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• pp.280-285
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• 1990

Biotransformation of progesterone to 11 $\alpha$ -hydroxyprogesterone by growing cells of Rhizopus nigricans was investigated. As the concentration of progesterone increased, the specific growth rate of R. nigricans decreased linearly, and consequently the conversion yield lowered. The hyphae of the microorganism were observed to become thicker, shorter, and more densely branched at high concentrations of progesterone. In order to improve the process productivity, biotransformation was conducted with continuous addition of progesterone. When the substrate was added continuously at a rate of 0.86 g/hr for 30 hrs, overall conversion yield reached upto 56% while a single addition of the same amount of progesterone yielded about 40% eonversion. When additional feeding of glucose was carried out upon its depletion, an improved br'oconversion yield upto 68% was obtained.

• 한국에너지공학회:학술대회논문집
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• 한국에너지공학회 2001년도 춘계 학술발표회 논문집
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• pp.159-162
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• 2001

• Investigative Magnetic Resonance Imaging
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• 제17권3호
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• pp.224-231
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• 2013

목적 : 유방암이 진단된 환자에서 시행한 자기공명영상에서 배경 실질 조영 정도에 따른 추가적인 조직 검사율 및 악성률의 차이를 알아 보고자 하였다. 대상 및 방법 : 유방암을 진단받고 유방 자기공명영상을 촬영한 322명의 환자를 대상으로, 2명의 영상의학과 의사가 이들의 유방 자기공명영상을 분석하여 배경 실질 조영 증강 정도를 평가하였으며, 판독지를 통해 추가적인 BI-RADS 범주 4 이상의 병변 유무를 확인하였다. 추가적인 BI-RADS 범주 4 이상의 병변에 대해서는 조직검사를 시행하였고, 악성률을 구하기 위해 조직검사 결과를 확인하였다. 결과 : 총 322명의 유방암 환자의 배경 실질 조영 증강 단계별 환자수는 최소 조영 증강 47.5%, 경한 조영 증강 28.9%, 중간 조영 증강 12.4% 그리고 현저한 조영 증강 11.2%였다. 이 중 70예에서 추가적으로 악성이 의심되는 조영 증강 병변이 발견되었고, 4예를 제외한 66예에서 조직 검사가 시행되었다. 배경 실질 조영 증강이 적은 경우 (최소/경한 조영 증강)와 많은 경우 (중간/현저한 조영 증강) 에 따른 조직 검사율은 각각 19.9%, 22.3%이었고, 악성률은 각각 6.5%, 5.2%이었으나, p-value가 각각 0.77, 0.88로 통계적으로 유의한 차이를 보이지 않았다. 결론 : 유방암이 진단된 환자에서 시행한 자기공명영상에서 배경 실질 조영 정도와 조직 검사율 및 악성률 사이에는 차이가 없었다.

• 한국전자통신학회논문지
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• 제7권4호
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• pp.833-837
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• 2012

SC1(Standard Cleaning) 시간을 줄여 STI 측벽에서의 실리콘 손실 및 과도절개를 최소화하여 DRAM에서의 데이터 유지시간을 증가시키는 방법을 제안한다. SC1 시간 최적화를 통해 STI 상층 모서리부에서의 기생 전기장을 약화시킴으로서 Inverse Narrow Width 효과를 감소시키면 셀 트랜지스터의 Subthreshold 누설의 증가없이 채널 도핑농도가 감소하게 된다. 이것은 셀 접합에서 P-Well간 공핍 영역에서의 전기장을 최소화하여 일드나 데이터 유지시간의 증가를 보여 주었다.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송∙미디어공학회 2020년도 추계학술대회
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• pp.237-240
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• 2020

The fine-tuned neural network (NN) model for a whole temporal portion in a video does not always yield the best quality (e.g., PSNR) performance over all regions of each frame in the temporal period. For certain regions (usually homogeneous regions) in a frame for super-resolution (SR), even a simple bicubic interpolation method may yield better PSNR performance than the fine-tuned NN model. When there are multiple NN models available at the receivers where each NN model is trained for a group of images having a specific category of image characteristics, the performance of Quality enhancement can be improved by selectively applying an appropriate NN model for each image region according to its image characteristic category to which the NN model was dedicatedly trained. In this case, it is necessary to signal which NN model is applied for each region. This is very advantageous for image restoration and quality enhancement (IRQE) applications at user terminals with limited computing capabilities.

• 한국정밀공학회지
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• 제26권8호
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• pp.142-147
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• 2009

Spinal fixation systems provide surgical versatility, but the complexity of their design reduces their strength and fatigue resistance. There is no published data on the mechanical properties of such screws. Screws were assembled according to a vertebrectomy model for destructive mechanical testing. A group of two assemblies was tested in static compression. One group was applied to surface a grit blasting method and another group was applied to surface a bead blasting method. Modes of failure, yield, and ultimate strength, yield stiffness, and cycles to failure were determined for six assembles. Static compression 2% offset yield load ranges was from 327 to 419N. Fatigue loads were determined two levels, 37.5% and 50% of the average load from static compression ultimate load. An assembly of bead blasting treatment only achieved 5 million cycles at 37.5% level in compression bending.

• 한국응용과학기술학회지
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• 제29권1호
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• pp.81-87
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• 2012

The biodiesel production characteristics in a pulsed-corona plasma reactor has been investigated through parametric tests. Transesterification of rapeseed oil together with camelina oil was done with the change of such variables as voltage of power, molar ratio, KOH catalyst and temperature. The energetic electrons emitted from pulsed-corona plasma has contributed to the enhancement of yield on rapeseed oil in short time (15 min). The higher yield on camelina oil was observed in 5 min. The optimal parameters were shown as the voltage of 23 kV, the molar ratio of 5/1, the content of KOH catalyst of 0.6 wt% and the temperature of $28^{\circ}C$ under the rotating rate of spark gap of 900 rpm.

• Plant Breeding and Biotechnology
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• 제5권4호
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• pp.371-389
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• 2017

Supplying sufficient rice to growing populations is a global challenge. Hybrid indica rice varieties exploiting heterosis have increased yields, but inter-subspecific crosses between indica and japonica varieties are hampered by sterility. Examination and genetic understanding of yield heterosis in indica/japonica crosses addressing yield barriers are basic requirements. In this study, QTLs for heterosis of yield traits were identified in indica-japonica recombinant inbred lines (RILs) using a total of 178 RILs originating from Dasanbyeo (indica) ${\times}$ TR22183 (japonica) (DT-RILs) and their backcrossed populations. Nine of sixty-six major quantitative trait loci (QTLs) identified in DT-RILs exhibited heterosis. Heterosis QTLs clustered with other traits on chromosomes 1, 4, and 8, and clusters were conserved between different RILs. The clusters contained several known yield enhancement genes/QTLs. Specific heterotic allele combinations contributed to four major heterosis QTLs, particularly for panicle and spikelet number traits. Heterosis for yield and yield-related traits was explained by the harmonized effects of overdominance, dominance, and epistatic interactions in inter-subspecific breeding populations.

• 한국산학기술학회논문지
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• 제15권7호
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• pp.4475-4481
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• 2014

저화질 이미지의 화질 개선에는 전통적으로 히스토그램균등화 기법이 사용되어 왔다. 히스토그램균등화 기법은 입력 이미지의 누적밀도함수를 변환함수로 사용하는 기법으로 이는 이론상 최대의 엔트로피를 가지지만 주관적 화질 측면에서는 백화현상이 나타나는 문제점이 있다. 본 논문에서는 히스토그램균등화 기법 기반의 가중 히스토그램 균등화 기법을 제안한다. 이는 인간의 시각특성을 반영한 Weber-Fechner 법칙을 사용하며 입력영상에 독립적인 변환함수를 제공하는 여러 이미지 화질 개선 기법들이 가지는 문제점을 해결하기 위해서 동적영역 재조정 과정을 포함한다. 최종적으로 재조정된 동적영역 범위 내에서 Weber-Fechner 법칙을 적용한 변환함수와 히스토그램균등화 기법을 통해 얻어진 변환함수간의 가중 평균을 통하여 변환함수를 생성한다. 실험결과 제안하는 알고리즘은 주관적 화질 측면에서 대비비를 효과적으로 향상시키는 것을 보여주며, 엔트로피 또한 비교에 사용된 여러 이전의 방법들과 비교하여 유사하거나 높은 값을 가지는 것을 볼 수 있었다.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.369-369
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• 2017

To improve the reclaimed land soil, we put organic materials (Chopped kenaf, decomposed rice hull, rice straw, pellet type manure compost) into reclaimed land for 3,000 kg per 10a. As a result, EC of reclaimed soil was lowered by 58% ($1.2dS/m{\rightarrow}0.5$), content of soil organic material was risen from 6.7 g/kg to 16.0 (1.4 fold ${\uparrow}$), porosity of soil was elevated from 1.57 % to 1.31 (16.6% ${\downarrow}$), soil hardness was reduced from 20.2 mm to 17.9 (11.4% ${\downarrow}$) and plow layer soil was deepen from 19.8 cm to 26.8 (35% ${\uparrow}$). In the wake of physiochemical improvement of reclaimed soil, the growth phase of crops became better contrast to non-treatment. For example the plant height of Kenaf (Hibiscus cannabinus L.) cultivated in reclaimed land containing organic materials was lengthen by 18.8%. Especially, the improvment effect of pellet type manure compost and rice straw was more preferable. When the kenaf was cultivated in reclaimed land containing organic materials, the yield was become higher. The average yield of organic materials treatment was 9,218 kg/10a, and it was 2.1 times higher than non-treatment (4,368kg/10a). And the effective treatments to increase yields were pellet type manure compost (10,848 kg/10a, 148% ${\uparrow}$), rice straw (120% ${\uparrow}$) and chopped kenaf (95% ${\uparrow}$). To intensify the effect of physicochemical enhancement of reclaimed land soil and improving yields, we put into various physical types of organic materials (pellet type, liquid type, powdered type). The most effective organic materials type for enhancement of physicochemical properties (EC of reclaimed soil was lowered, content of soil organic material was risen, porosity of soil was elevated, soil hardness was reduced, plow layer soil was deepen) was pellet. And source to maintain better growth phase and get more yield were liquid and pellet types. When we used pellet type organic material, the plant height of kenaf was lengthen by 41% in comparison with non-treatment and yield was more than 122% more. And also liquid type could get more yield (by 127%) and growth phase (by 38%)