$Ar/N_2 및 Kr/N_2$혼합가스의 교류절연파괴 특성

이상우,김인식,이동인,이광식,김이국,Lee, Sang-Woo,Kim, In-Sik,Lee, Dong-In,Lee, Kwang-Sik,Kim, Lee-Kook 대한전기학회 2001 전기학회논문지C Vol.50 No.12

In this paper, the ac breakdown characteristics of pure Ar, Kr and $N_2$ gas with gas pressure range of 58.8-137.3[kPa] under uniform and non-uniform fields were investigated, and the measured values were compared with those In Ar/$N_2$ and Kr/$N_2$ gas mixtures with pressure varying. Summarizing the experimental results, the breakdown voltages of Pure $N_2$gas, under uniform and non-uniform fields, were increased about 4.8 and 1.1 times than those of pure Ar gas, and about 4.4 and 1.2 times than those of pure Kr gas, and the ac breakdown voltage increased with the pressure increasing. The breakdown voltages of Ar/$N_2$ gas mixtures were decreased with decreasing the mixture ratio of Pure $N_2$ gas. In case of Ar(85%)/$N_2$ (15%) and Ar(70%)/$N_2$ (30%) gas mixtures comparing to the pure Ar gas, the breakdown voltages under uniform field were increased about 1.8 and 2.2 times, and under non-uniform field were increased about 1.1 and 1.3 times at the pressure of 101.3[kPa]. Also, in case of Kr(85%)/$N_2$ (15%) and Kr(70%)/$N_2$ (30%) gas mixtures comparing to the pure Kr gas, the breakdown voltages under uniform field were increased about 1.7 and 2.0 times, and under non-uniform field were increased about 1.0 and 1.2 times. Corona inception voltage of Kr(70%)/$N_2$(30%) gas mixtures under non-uniform fields were increased about 1.28 times than those of Ar(70%)/$N_2$ (30%) gas mixtures. In case of practical incandescent lamps, luminous and lifetime of Kr(70%)/$N_2$ (30%) gas mixtures were increased about 1.15 and 1.21 times than those of Ar(70%)/$N_2$ (30%) gas mixtures.

RF 스퍼터링법을 이용한 $LiNbO_3/Si$구조의 전기적 및 구조적 특성

이상우,김광호,이원종,Lee, Sang-Woo,Kim, Kwang-Ho,Lee, Won-Jong 한국전기전자재료학회 1998 전기전자재료학회논문지 Vol.11 No.2

The $LiNbO_3$ thin films were prepared directly on Si(100) substrates by conventional RF magnetron spurttering system for nonvolatile memory applications. RTA(Rapid Thermal Annealing) treatment was performed for as-deposited films in an oxygen atmosphere at 600 $^{\circ}C$ for 60 s. The rapid thermal annealed films were changed to poly-crystalline ferroelectric nature from amorphous of as-deposition. The resistivity of the ferroelectric $LiNbO_3$ film was increased from a typical value of $1{\sim}2{\times}10^8{\Omega}{\cdot}cm$ before the annealing to about $1{\times}10^{13}{\Omega}{\cdot}cm$ at 500 kV/cm and reduced the interface state density of the $LiNbO_3/Si$ (100) interface to about $1{\times}10^{11}/cm^2{\cdot}eV$. Ferroelectric hysteresis measurements using a Sawyer-Tower circuit yielded remanent polarization ($P_r$) and coercive field ($E_c$) values of about 1.2 ${\mu}C/cm^2$ and 120 kV/cm, respectively.

소형 연료전지 연계형 DC GRID 부하 특성

이상우,이상철,권오성,배준형,박태준,강진규,이동하,Lee, Sang-Woo,Lee, Sang-Cheol,Kwon, O-Sung,Bae, Jun-Hyung,Park, Tae-Joon,Kang, Jin-Kyu,Lee, Dong-Ha 한국태양에너지학회 2012 한국태양에너지학회 논문집 Vol.32 No.suppl3

In recent years, understanding the dynamics of DC distribution system has become critically important due mainly to the increasing needs for the interconnection of DC distributed generators and the (DC-based) electric vehicle (EV) charging systems. In this paper, the characteristics of the DC grid system connected to the compact proton exchange membrane fuel cell (PEMFC) has been studied. In particular, the voltage and current transient phenomena were measured by varying the load of the DC grid system. Also, the voltage and current ripple were measured at the different load conditions. Our experimental results clearly manifested that the study contributes to the establishment of fundamental method to characterize the small DC grid system including distributed generation.

3D 캐릭터에서의 자동 립싱크 MAYA 플러그인 개발

이상우,신성욱,정성택,Lee, Sang-Woo,Shin, Sung-Wook,Chung, Sung-Taek 한국인터넷방송통신학회 2018 한국인터넷방송통신학회 논문지 Vol.18 No.3

본 논문에서는 한국어를 기반으로 음성 데이터와 텍스트 정보에서 한국어 음소를 추출하고 분할된 음소들을 사용하여 정확하고 자연스러운 3D 립싱크 애니메이션을 제작하기 위한 오토 립싱크 Maya 플러그인을 개발하였다. 여기서 개발된 시스템에서는 음소 분할은 Microsoft Speech API 엔진 SAPI에서 제공하는 49개의 음소를 참조하여 한글에 사용되는 음소들을 모음 8개, 자음 13개로 분류하였다. 또한 모음과 자음의 발음들은 다양한 입모양을 가지지만 일부 동일한 입모양에 대하여 같은 Viseme을 적용할 수 있도록 구현하였다. 이를 바탕으로 파이썬(Python) 기반의 오토 립싱크 Maya 플러그인을 개발하여 립싱크 애니메이션이 한 번에 자동으로 구현할 수 있게 하였다. In this paper, we have developed the Auto Lip-Sync Maya plug-in for extracting Korean phonemes from voice data and text information based on Korean and produce high quality 3D lip-sync animation using divided phonemes. In the developed system, phoneme separation was classified into 8 vowels and 13 consonants used in Korean, referring to 49 phonemes provided by Microsoft Speech API engine SAPI. In addition, the pronunciation of vowels and consonants has variety Mouth Shapes, but the same Viseme can be applied to some identical ones. Based on this, we have developed Auto Lip-sync Maya Plug-in based on Python to enable lip-sync animation to be implemented automatically at once.

XLPE 절연체의 트리 채널내 보이드방전에 의한 AE신호로 절연열화 검출 기법 연구

이상우,Lee, Sang-Woo 한국조명전기설비학회 2006 조명·전기설비학회논문지 Vol.20 No.2

본 논문은 전력 케이블의 절연체인 XLPE 시료에 상용주파수 교류전압을 인가하였을 때, 절연열화에 의한 보이드방전 펄스신호와 AE신호 및 트리진전 특성을 검출하고 관찰하였다. 또한 XLPE 절연체의 트리 채널내 인가전압에 따라 보이드방전 펄스신호와 AE신호를 각각 관측하였다. 실험 결과 전력 케이블의 절연체인 XLPE 시료의 보이드 존재 유 무에 따른 트리진전 형상은 보이드 존재시에는 수지형으로 성장하였으나, 무보이드시에는 수초형으로 성장하였다. XLPE 절연체내의 트리진전 특성은 보이드 존재시에는 열화시간이 경과함에 따라 급격히 증가하였으나, 무보이드시에는 열화 시간이 경과함에 따라 트리의 성장 형상은 감소되는 것으로 나타났다. 전력 케이블 절연체인 XLPE의 트리 채널내 보이드방전에 의한 AE신호의 주파수 스펙트럼으로 분석한 결과, AE신호의 크기에 따라 변화되었으며 그 주파수 영역은 대략 1.0[MHz] 이하의 분포인 것으로 관측되었다. In this paper, to detect and observation the void discharges pulse signal, AE signals and tree growth characteristics in case the high voltage is applied to a XLPE sample for a power cable. We also examined the partial discharge current pulse and AE signals with the increase of the applied voltage in XLPE insulation. The experimental results show that a branch-type tree grows in the presence of the voids, and a bush-type tree grows in the absence of the voids in both samples. A rate of tree growth increases abruptly in proportional to the deterioration time in the presence of the of the voids, but in the absence of the voids, a rate of tree growth decreases as time goes by and finally a breakdown occurs. The frequency band of AE signals that are generated from the partial discharges in a XLPE sample, one of solid dielectric materials, is about 1.0[MHz].

중국증권시장의 정보이전효과에 관한 연구

이상우,이의경,Lee, Sang-Woo,Lee, Eui-Kyung 한국데이터정보과학회 2012 한국데이터정보과학회지 Vol.23 No.6

본 논문은 중국의 상해, 심천, 홍콩증권시장간의 정보이전효과를 연구한 것이다. 세 개의 중국 증권시장은 모두 미국의 증권시장수익률에 강하게 영향을 받는데 그 정도는 개방화가 제일 잘된 홍콩증권시장이 가장 크며 상해증권시장, 심천증권시장의 순으로 영향을 받는 것으로 나타나고 있다. 상해증권시장이나 심천증권시장은 서로 간에 수익률이전효과나 변동성전이효과가 존재하지 않지만 이 두 시장은 모두 홍콩증권시장수익률의 영향을 받는 것으로 나타났다. 하지만 미국증권시장의 움직임을 통제하면 이러한 효과는 사라지게 되어 중국의 증권시장간의 정보이전효과는 존재하지 않는 것으로 나타나고 있다. 이러한 결론은 중국의 세 개의 증권시장이 상호독립적인 성격이 강하다는 것을 의미하며, 중국의 증권시장 연구 시 시장 간의 독립성을 반영해야 할 것으로 생각된다. This study examines stock market co-movement among three China stock markets: Shanghai stock market, Shenzhen stock market, Hongkong stock market. US stock market leads three China stock markets and Honkong stock market leads Shanghai and Shenzhen stock market. But there are no lead-lag effects among China stock markets after controlling US stock market effect. These results could be important for the investors and firms that are interested in China stock markets.

Review of Issues and Problems in Using Landscape Ecology Indices

이상우,윤은주,이인성,Lee Sang-Woo,Yoon Eun-Joo,Lee In-Sung Korean Institute of Landscape Architecture 2004 韓國造景學會誌 Vol.32 No.5

경관생태지수는 녹지의 이질성(Heterogeneity)을 계량화하기 위하여 제안되고 발전되어 왔다. 지난 수십년간 많은 연구에서 경관생태지수가 광범위하게 사용되어 그 효용성이 인정되었지만, 경관생태지수의 사용에 따른 많은 문제점들이 제기되고 있다. 본 연구의 목적은 경관생태지수 사용에 따른 고려사항과 문제점들을 기존 연구들을 통해 고찰하고, 이를 기초로 적절한 응용방법을 제안하고자 하는 것으로, 지수의 문제점을 내재적인 문제들과 응용상의 문제들로 구분하여 논의하였다. 지수 자체의 내재적인 문제로는 녹지구조와 기능과의 관계, 녹지구조의 측정 및 대표, 그리고 지수들의 불안정성 등을 들 수 있으며, 응용상의 문제점들로는 지수 선택, 스케일 변화와 피복 분류과정에 개입된 문제, 해석상의 오류 등을 들 수 있다. 이러한 문제들을 최소화하는 방안으로는 첫째, 가설에 입각한 연구가 필요하며, 둘째, 측정하고자 하는 녹지의 공간적 특성을 명확히 규정하여야 하고, 셋째, 변위가 예측 가능한 지수를 사용해야 하고, 넷째, GIS나 인공위성 자료의 축척을 변화시키지 말아야 하며, 마지막으로 다섯째, 피복분류 알고리즘을 사용하여 분류상 오류를 최소화해야 한다는 점이다.

상자형 복부판의 좌굴 거동에 관한 연구

이상우,권영봉,Lee, Sang Woo,Kwon, Young Bong 한국강구조학회 1997 韓國鋼構造學會 論文集 Vol.9 No.1

The buckling behavior of the web of steel girders are largely dependent on the size and the location of stiffeners and the restraining effect of top and bottom flanges. Elastic and inelastic buckling analyses based or the Spline Finite Strip Method were executed to study the stiffening effect of the longitudinal stiffener on the web of box girders and to find how the top and bottom flanges had effects on the web, where geometric boundary conditions were limited by both hinged, both fixed and the flange sections. The basic assumption for the longitudinal end boundary conditions was that the vertical stiffeners had the rigidity enough to force nil deflection line on the web panel so that the junction line between web and vertical stiffener was assumed to be hinged boundary conditions. The provisions on the longitudinal stiffener of the plate and box girders of the Korean Standard Highway Bridge Specifications(1995) and AASHTO Specifications(1994 LRFD) were compared with the results obtained numerically for the various longitudinal stiffener size of box girders. Simple equations and design curves for the longitudinal stiffener of the web were proposed for the practical use.

수확기(收穫機)의 성능향상(性能向上)에 관(關)한 연구(硏究)(I) - 수도(水稻)의 탈립저항력(脫粒抵抗力)에 관(關)하여

이상우,허윤근,Lee, Sang Woo,Hur, Yun Kun 충남대학교 농업과학연구소 1981 Korean Journal of Agricultural Science Vol.8 No.2

충남농촌진흥원(忠南農村振興院) 포장(圃場)에서 표준시비법(標準施肥法)으로 재배(栽培)한 Japonica형(型) 품종(品種) 이이(裡里)348호(號), 이이(裡里)345호(號) 및 밀양(密陽)15호(號) 3개斗(個)와 Indica ${\times}$ Japonica hybrid형(型) 품종(品種) 밀양(密陽)23호(號), 이이(裡里)342호(號), 수원(水原)294호(號)의 4개(個), 계(計) 7 개(個) 품종(品種)에 대해 적정수확기간(適定收穫期間)을 중심(中心)으로 9월(月)28일(日)부터 10월(月)20일(日)까지 2일간격(日間隔)으로 3축방향(軸方向)에 대(對)하여 탈립저항력(脫粒低抗力)을 측정(測定)하였다. 10월(月)1일(日) 채취(採取)된 시료(試料)를 실험실(實驗室)에서 자연건조(自然乾燥)시키면서 함수율별(含水率別) 탈립증항력(脫粒拯抗力)을 측정(測定)하였다. 본(本) 연구(硏究)의 결과(結果)는 다음과 같다. 1. 외력(外力)이 지경(枝梗)과 평행방향(平行方向)으로 작용(作用)될 경우 Japonica형(型) 품종(品種)의 탈립저항력(脫粒低航力) 평균(平均) 113grdljTEk. 2. 외력(外力)이 지경(枝梗)과 $90^{\circ}$ 측방향(側方向)으로 작용(作用)될 경우의 탈립증항력(脫粒拯抗力)은 평행방향(平行方向)과 비교(比較)하여 Japonica형(型) 품종(品種)은 33~50%인 59.8~115.0gr이었고, Indica ${\times}$ Japonica hybrid형(型) 품종(品種)은 7~21%인 9.8~28.2gr으로 현저(顯著)히 작았다. 3. 기온(氣溫)이 영하(零下)로 강하(降下)하지 않은 본실험기간중(本實驗期間中) 예취일(刈取日)에 따른 탈립심지항력(脫粒甚至抗力)의 변화(變化)는 크게 없었다. 4. 예취후(刈取後) 자연건조(自然乾燥)에 따른 탈립심지항력(脫粒甚至抗力)은 함수율(含水率)의 감소(減少)와 함께 감소(減少)하였다. 5. 이삭 부위별(部位別) 탈립서항력(脫粒鼠抗力)은 상부측(上部側)에 비(比)해 하부측(下部側)에서 약간 큰값을 나타냈다. Threshing forces of seven varieties, that is, three Japonica type varieties-Irri 348, Irri 345, and Milyang 15, and four Indica type varieties-Milyang 23, Irri 342, Suweon 294 and Suweon 287-, which have been cultivated in the standard fertilization field being at Chungnam Provincial Office of Rural Development, Youseong, Chungnam-do, they were measured every other day in the period from September 28 to October 20 which were included the proper harves ting time. Also the threshing forces were checked in three-dimensional directions. Relationships between threshing forces and moisture contents of the unthreshed rice were examined in the laboratory as dried in the natural condition. The results of this study were as follows; 1. The mean threshing force of Japonica type varieties was about 1969r. and that of Indica type varieties was about 113gr. when external force was loaded in the direction parallel to the grain. 2. The threshing force bent to the grain was about 9.8through 28.2gr. equal to 7 through 21 percent to the threshing force parallel to the grain in Indica type varieties meanwhile about 59.8 through 115.0gr equal to 33 through 50 percent in Japonica type varieties. 3. Under the warmer temperature than $0^{\circ}C$, the change of threshing forces was not great in this experimental period on the harvesting dates. 4. The threshing force decreased s lightly as moisture content decreased in natural drying under the shade after cutting. 5. The threshing force of the lower portion was a little biger than that of the upper portion in an ear.

공간성, 호소유형 및 형태복잡도 지수를 이용한 토지이용과 호소수질의 관계 연구

이상우,황순진,Lee, Sang-Woo,Hwang, Soon-Jin 한국조경학회 2007 韓國造景學會誌 Vol.34 No.6

Land use types within a watershed closely are related with the water quality characteristics of receiving water bodies. Despite of a numerous studies suggesting a strong relationship between water quality and land use, there have been increasing concerns about the geographical variation and a lack of spatial integration in that relationship, which are essential to implementing these findings into land use planning and management. In the meantime, edges mediate the material flux between adjacent systems. This mediating effect of edges is strongly related to the complexity of their shapes. Land use activities within a watershed have a direct impact on the water quality of adjacent aquatic systems, and hydrological processes carry residuals from watershed into adjacent aquatic ecosystems through the edges. Therefore, the geometry of reservoirs theoretically affects the relationship between land uses in the watershed and the quality of receiving bodies of water. In this light, this study integrates the geo-spatial dimensions of land uses in the watershed using GIS and landscape indices in order to explore the relationship between land uses and water quality. Water quality characteristics, land uses and geometry of 133 randomly sampled reservoirs were correlated, based on buffer zones and types of reservoirs. The findings showed that land uses, particularly urban land uses, significantly affect water quality characteristics including BOD, COD, TN and TP, and geometry of reservoirs reduces the concentration of pollutant and nutrients in reservoirs. One of results indicates that the relationship between land use and water quality and effects of spatial dimension may vary with types of reservoirs and pollutants. These results suggest that lakeshore areas are important, particularly for TN reduction and call for a caution to land use activities nearby shoreline areas for sustaining better water quality.