• 대한전기학회:학술대회논문집
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• 대한전기학회 1992년도 하계학술대회 논문집 B
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• pp.775-778
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• 1992

In 1980, 154kV OF cable was installed at the Cheong-Pyeong pumped-storage power station. Effective head of this pumped-storage station is 250m between upper and lower re-servior and length of cable route is 750m. However, several failures have happened owing to steep slope during the operation. 154 kV XLPE cable was applied for this power station to eliminate a lack of stability on account of steep slope and successfully installed in 1991. Meanwhile, installation procedure brings about many problem to be solved. In this paper, we describe the counter measure of cable sliding phenomena caused by heat shrinkage as well as the method of installation of cable under the steep slope condition. And hereafter, we think this paper will be a good reference to design and installation of 154kV XLPE cables in steep slope turnnel at urban areas.

• Journal of Microbiology and Biotechnology
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• 제19권12호
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• pp.1603-1611
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• 2009

High-cell-density cultivation of yeast was investigated using the agricultural waste products corn steep liquor (CSL) and molasses. The Saccharomyces cerevisiae KV-25 cell mass was significantly dependent on the ratio between C and N sources. The concentrations of molasses and CSL in the culture medium were statistically optimized at 10.25% (v/v) and 16.87% (v/v), respectively, by response surface methodology (RSM). Batch culture in a 5-l stirred tank reactor using the optimized medium resulted in a cell mass production of 36.5 g/l. In the fed-batch culture, the feed phase was preceded by a batch phase using the optimized medium, and a very high dried-cell-mass yield of 187.63 g/l was successfully attained by feeding a mixture of 20% (v/v) molasses and 80% (v/v) CSL at a rate of 22 ml/h. In this system, the production of cell mass depended mainly on the agitation speed, the composition of the feed medium, and the glucose level in the medium, but only slightly on the aeration rate.

• 대한수학회보
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• 제52권2호
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• pp.661-677
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• 2015

In this paper, we consider the following Kirchhoff-type Schr$\ddot{o}$dinger system $$\{-\(a_1+b_1{\int}_{\mathbb{R^3}}{\mid}{\nabla}u{\mid}^2dx\){\Delta}u+{\gamma}V(x)u=\frac{2{\alpha}}{{\alpha}+{\beta}}{\mid}u{\mid}^{\alpha-2}u{\mid}v{\mid}^{\beta}\;in\;\mathbb{R}^3,\\-\(a_2+b_2{\int}_{\mathbb{R^3}}{\mid}{\nabla}v{\mid}^2dx\){\Delta}v+{\gamma}W(x)v=\frac{2{\beta}}{{\alpha}+{\beta}}{\mid}u{\mid}^{\alpha}{\mid}v{\mid}^{\beta-2}v\;in\;\mathbb{R}^3,\\u,v{\in}H^1(\mathbb{R}^3),$$ where $a_i$ and $b_i$ are positive constants for i = 1, 2, ${\gamma}$ > 0 is a parameter, V (x) and W(x) are nonnegative continuous potential functions. By applying the Nehari manifold method and the concentration-compactness principle, we obtain the existence and concentration of ground state solutions when the parameter ${\gamma}$ is sufficiently large.

• KIEE International Transactions on Electrophysics and Applications
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• 제3C권5호
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• pp.165-170
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• 2003

This paper presents development of solid core suspension disc insulators (cap and cap suspension disc insulator) for replacing cap and pin suspension disc insulators in overhead transmission and distribution lines which expose to lightning discharges. By this means the punctured problem caused by steep front surge voltage created by lightning discharge on the lines can be solved. The solid core suspension insulator was designed and constructed based on the dimensions of conventional suspension disc insulators (cap and pin insulators). The insulators are made of alumina porcelain. The electrical and mechanical characteristics of the solid core suspension insulators were carried out. The puncture test was performed in the air by applying steep front impulse voltage with amplitude about 2.5 per unit of 50% flashover (CFO) of the insulator unit at negative standard lightning impulse $1.2/50\;\mu\textrm{s}$ with steepness up to $9200\;kV/\mu\textrm{s}$. The testing results show that solid core suspension disc insulators are not punctured eventhough the steepness of the steep front impulse voltage was increased up to $9200\;kV/\mu\textrm{s}$.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2000년도 추계학술발표대회 및 bio-venture fair
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• pp.372-375
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• 2000

Lactobacillus cristatus KLB 46 isolated from Korean woman was grown on supplemented whey medium and medium compositions were optimized for maximum viable cell count. Among the nitrogen sources tested, beef extract yielded the highest viable cell number. When corn steep liquor was applied as an additional nitrogen source, the viable cell number was highest $(3.11{\times}10^9\;CFU/ml)$ in the medium containing 50g/ l corn steep liquor and 10g/ l beef extract. The highest viable cell $count(5.00{\times}10^9\;CFU/ml)$ was obtained from the supplemented whey medium that contains beef extract(10g/ l ), corn steep liquor(50g/ l ), tween 80(0.1%, v/v) and trace amounts of sodium acetate(5g/ l ), dipotassium phosphate(2g/ l ), magnesium sulfate(0.1g/ l ), and manganese sulfate (0.05g/ l ).

• 한국지반환경공학회 논문집
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• 제15권9호
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• pp.77-85
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• 2014

현재 소방방재청에서는 국가재난관리시스템(NDMS, National Disaster Management System)을 운영 중에 있으나 급경사지정보의 입력 및 관리를 위한 기능이 단순한 DB 입력 관리 기능으로 존재하고 있어 신속하고 체계적인 급경사지 관리에 어려움이 존재하고 있는 실정이다. 최근 빈번한 국지성 집중호우에 의한 우면산 산사태, 춘천 산사태 등의 대규모 산사태가 증가하고 있어 급경사지의 위험도가 급증하고 있으며, 국가 재해 재난이 빠른 추세로 증가하고 있다. 이에 대한 선제적 대응 및 관리의 고도화를 위해서는 급경사지 방재 및 관리를 위한 GIS 기반의 급경사지정보 통합관리시스템의 개발이 필요하다. 본 연구에서는 급경사지 재해 재난에 대한 선제적 대응 및 안전한 관리를 위한 국가 차원의 GIS 기술 기반의 급경사지정보 통합관리시스템을 개발하였다. 급경사지정보 통합관리시스템은 급경사지 일제조사서기반의 지표면정보와 지하공간정보의 입력 및 출력 DB를 설계 구축하여 개발하였다. 본 연구를 통하여 개발한 급경사지정보 통합관리시스템은 지표면정보 입력모듈, 급경사지 주변 지하공간정보 DB 실시간 연계 입력모듈, V-World 배경지도 기반의 급경사지 검색 분석 관리를 위한 GIS 모듈, 급경사지정보 통합정보시스템 사용자 관리모듈, 급경사지정보 활용 연계시스템과의 실시간 연계 인터페이스모듈로 구성된다. 또한 개발한 급경사지정보 통합관리시스템에 대하여 자료저장률, 동시접속 시 시스템 안정성, 처리속도의 일관성에 대한 안정성테스트를 수행하여 급경사지정보 통합관리시스템의 연결성을 확보하였다.

• 한국콘텐츠학회논문지
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• 제20권6호
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• pp.230-240
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• 2020

최근 4차 산업혁명에 대한 사회적 논의가 활발히 전개되고 있으며, 이러한 4차 산업혁명은 우리사회와 도시 및 주거 그리고 산업공간에도 지대한 영향을 미칠 것으로 예측하고 있다. 특히 4차 산업혁명에 따른 기술발달은 주거양식과 문화에 광범위한 변화를 초래할 것으로 예측되므로, 미래 변화의 크기와 방향을 미리 파악하여, 향후 미래주거에 대해 준비해야할 과제와 전략에 대한 선제적 대응이 필요하다. 본 연구의 목적은 4차 산업혁명이 초래할 미래주거에 대한 중장기 변화방향과 특성을 예측하여, 향후 사회적·공간적·기술적 영향과 이슈 등을 정의하고 이에 대한 정책적 대응 방안을 모색하는데 있다. 연구의 범위는 근미래(10년 이내), 중미래(10년~20년), 먼 미래(20년 이후) 등으로 구분하고, 주거형태, 주거공간, 입지, 주거수요, 건축기술, 스마트화 등 미래 주거변화의 방향과 내용, 파생되는 주거문제와 특성을 예측하였다. 미래예측을 위한 방법론으로 STEEP(V)를 활용하였으며, 빅데이터 및 통계지표를 활용하여 기술적, 사회적 이슈를 도출하는 과정으로 각종 키워드를 수집하고 핵심 이슈를 도출하여 각 핵심이슈와 관련된 사회적 변화양상을 정리하였다. 본 연구에서 제안한 미래주거 예측 및 대응방안에 대한 전략은 미래주택 정책의 추진방향을 위한 기초적 자료로 활용가능하며, 정확한 예측보다 다각도의 빅데이터 자료를 통해 개연성 있는 합리적 결과를 도출하는 프로세스를 제안하였다는 것에 의의를 갖는다.

• Food Science and Biotechnology
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• 제14권5호
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• pp.561-565
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• 2005

In this study, we attempted to assess the effects of lactate and com steep liquor (CSL) on the production of bacterial cellulose (BC) by Gluconacetobacter persimmonis $KJ145^T$. The optimal condition for the production of BC was a lactate concentration of 1% (w/v) and a CSL concentration of 10% (w/v). Under these optimal conditions, 6 days of fermentation produced 6.90 g/L of BC. Both the BC production yield and cell growth increased continuously until the 20th day of fermentation, by which time 17.0 g/L had been produced. In a static culture trial, in which plastic containers were used as fermentation chambers for 6 days of fermentation, the BC production yield in the group initially cultured with 500 mL medium was higher than that of the 750 and 1000 mL media. In addition, the texture of the BC was examined according to its post-treatment in order to determine conditions for optimal textural characteristics. The strength, hardness, and other characteristics of the BC were negatively correlated with sucrose concentration, but were largely positively correlated with NaCl concentration. With regards to the effect of pH on textural change, BC strength and hardness were elevated at pH 2 and 8 but reduced at pH 4 and 6, indicating that the texture of the BC is extremely sensitive to treatment conditions.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2003년도 International Meeting on Information Display
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• pp.374-377
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• 2003

We reported researches of possibility of the usage of known electrooptical effects (EOE) for diffractive displays (DLCD). We found different EOEs provide the possibility of broad selection of steepness of volt-contrast characteristics at rather large steep of modulation without the usage polarizes. The data are represented much promising for broad development DLCDs.

• JSTS:Journal of Semiconductor Technology and Science
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• 제17권2호
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• pp.216-222
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• 2017

The most prominent challenge for MOSFET scaling is to reduce power consumption; however, the supply voltage ($V_{DD}$) cannot be scaled down because of the carrier injection mechanism. To overcome this limit, a new type of field-effect transistor using positive feedback as a carrier injection mechanism (FBFET) has been proposed. In this study we have investigated the electrical characteristics of a $Si_{1-x}Ge_x$ FBFET with one gate and one-sided $Si_3N_4$ spacer using TCAD simulations. To reduce the drain bias dependency, $Si_{1-x}Ge_x$ was introduced as a low-bandgap material, and the minimum subthreshold swing was obtained as 2.87 mV/dec. This result suggests that a $Si_{1-x}Ge_x$ FBFET is a promising candidate for future low-power devices.