측창 및 온실 폭이 자연환기 성능에 미치는 영향

이현우,우영회,이종원,Hyun Woo Lee,Young Hoe Woo,Jong Won Lee 국립한국농수산대학교 교육개발센터 2023 현장농업연구지 = Journal of practical agricultural resear Vol.25 No.1

In summer, the natural ventilation performance for varying greenhouse width is very important in the glasshouses for year round cultivation. The effect of the side openings and greenhouse width on natural ventilation performance was analyzed by simulation. The necessary ventilation rate with different solar radiation transmittance increased significantly when the outside temperature grows higher. The necessary ventilation rate of 40% transmittance was about half of that of 90% transmittance. In consequence, shading effect on temperature control in greenhouse is significant in summer. When the total area of the openings for ventilation is constant, the maximum ventilation rate happens when the area of roof openings is equal to the area of side openings. This maximum ventilation rate is about 3 times of that of the greenhouse with roof openings and without side openings. Therefore, the side openings are advantageous to improve the natural ventilation in greenhouses. As the greenhouse width increases, the influence of side openings on the ventilation rate is becoming smaller. If the natural ventilation rate of the greenhouse with roof and side openings is to become double of that of the roof openings only, the width should be narrower than 38.4m for the Venlo type and 64m for Wide span type.

관상동맥우회 이식편으로서의 우위대망동맥의 조직학적 특징

이현우,송현,유동곤,임한중,이재원,송명근,Lee, Hyun-Woo,Song, Hyun,Yoo, Dong-Gon,Lim, Han-Jung,Lee, Jae-Won,Song, Meong-Gun 대한흉부심장혈관외과학회 1999 Journal of Chest Surgery (J Chest Surg) Vol.32 No.10

Long term patency of arterial graft has been better than venous graft and redo coronary artery bypass grafting has been increasing, therefore, there has been an increasing need for alternative arterial grafts except internal thoracic artery(ITA). Material and Method: Right gastroepiploic arteries(RGEA) were harvested from 100 patients who had received gastrectomy for gastric cancer or ulcer. ITAs were obtained from 10 patients undergoing coronary artery bypass grafting. The length of RGEA was measured from the pyloric ring. Items of the morphometric and histologic study at the pyloric ring and sites of the 10cm and 20cm RGEA from the pyloric ring were luminal diameter, intimal thickness, medial thickness, wall thickness, degree of intimal hyperplasia, intimal thickness, medial thickness, wall thickness, degree of intimal hyperplasia, intimal thickness index, medial thickness index, and the number of discontinuities of the internal elastic lamina. Similar items were applied to the proximal site of ITAs. Result: The length of RGEA was 23${\pm}$2.7cm(range 17∼31cm). Comparing the 20cm RGEA with ITA, intimal thickness, medial thickness, wall thickness, and degree of intimal hyperplasia did not show any difference(p>0.05). However, 20cm RGEA was greater than ITA at the luminal diameter, intimal thickness index, and the number thickness and wall thickness in each site of the RGEA(pyloric ring, 10cm, 20cm) decreased from the pyloric ring to the distal sites(p<0.05). The degree of intimal hyperplasia and the number of discontinuities of the internal elastic lamina did not show any difference between the pyloric ring and 10cm, however, those of 20cm were smaller than these sites(p<0.05). RGEA had more number of discontinuities of the internal elastic lamina and rich smooth muscle cells in the media than ITA. Conclusion: The length and diameter of RGEA is good enough to reach most of the coronary arteries. Moreover, long term patency of RGEA may be improved, if anastomosed in the distal site.

석재가공용 다이아몬드 톱의 제조 및 특성

이현우,전우용,이오연,설경원,Lee Hyun-Woo,Jeon Woo-yong,Lee Oh-yeon,Seol Kyeong-won 한국분말야금학회 2004 한국분말재료학회지 (KPMI) Vol.11 No.5

The purpose of the present study is to determine an optimum composition using cheaper powders keeping with high performance of hard rock cutting diamond saw blade. With 50Fe-20(Cu . Sn)-30Co specimen, a part of Co was replaced by Ni(5%, 10%, and 15%, respectively). These specimens were hot pressed and sintered for predetermined time at various temperature. Sintering is performed by two different methods of temperature controlled method and specimen dimension controlled method. In order to determine the property of the sintered diamond saw blade, 3 point bending tester, X-ray diffractometer, and SEM were used. As the Co in the bond alloy was replaced by Ni, the hardness of the specimen increased. Thus the 50Fe-20(CuㆍSn)-15Co-15Ni specimen showed the maximum hardness of 104(HRB). The results of 3 point bending test showed that flexure strength decreased along with increase in Ni content. This is attributed to the formation of intermetallic compound(Ni$_{x}$Sn) determined by X-ray diffraction. The fracture surface after 3 point bending test showed that diamond was fractured in the specimen containing 0%, 5%, and 10%Ni, and the fracture occurred at the interface between diamond and matrix in the specimen containing 15%Ni. The cutting ability test showed that the abrasive property was not changed in the specimen containing 0%, 5%, and 10%Ni. The optimum composition determined in this study is 50Fe-20(CuㆍSn)-20Co-10Ni.

서초동(서울시 서초구)의 거미상

김주필(Joo Pil Kim),정혜리(Hye ri Jeong),김대희(Dae Hee Kim),박동우(Dong Woo Park),서재웅(Jae Woong Seo),이현우(Hyun woo Lee) 한국거미연구소 2017 한국거미 Vol.33 No.1

2016년 3월 31일부터 7월 31일까지 서울특별시 서초구 서초동에 위치한 서울고등학교 교정 일대를 서울고등학교 환경생물부 부원들이 채집 조사한 결과 20과 43속 53종의 거미가 조사 연구되어 이에 보고하는 바이다. From March 31st to July 31st in 2016, members of an environmental biology club at Seoul High School located in Seocho-gu, Seoul, Dae-Hee Kim, Dong-Woo Park, Jae-Woong Seo and Hyun-woo Lee, collected 20 families 43 genera 53 species of spiders and report the result of the study here.

공중 무선랜 시스템에서 로밍을 고려한 사용자 인증방식의 설계 및 구현

이현우,김정환,류원,윤종호,Lee, Hyun-Woo,Kim, Jeong-Hwan,Ryu, Won,Yoon, Chong-Ho 한국통신학회 2004 韓國通信學會論文誌 Vol.29 No.8B

본 논문은 무선랜 기술을 활용한 초고속 무선인터넷 서비스에서 사용자 인증방식에 사용되는 프로토콜의 설계와 구현에 관한 것이다. IEEE 802.l1b를 기반으로 한 공중 무선랜 서비스는 최근 고속 무선 인터넷 접속 솔루션으로써 각광받고 있다. 공중 무선랜 환경에서는 특히 중앙 집중화된 인증방법과 향상된 보안대책이 필요하며 사용자 단말의 이동 시 로밍에 대한 보장이 요구된다. 본 논문에서는 IEEE 802.1x에 기반의 사용자 인증보안 기능을 설계하고 방법과 실제 임베디드 리눅스를 기반으로 한 무선랜 Access Point(AP)에서 구현하여 동작을 시험하였으며. 로밍 시 필요한 IAPP 절차에 대하여 검토하였다. 또한 업체를 통한 상용화를 진행하며, KT 네스팟 인증시스템과 정상적인 연동기능 및 관리기능이 동작함을 확인하였다. Currently, Wireless LAN(WLAN) service is widely deployed to provide high speed wireless Internet access through the mobile stations such as notebook and PDA. To provide enhanced security and user access control in the public WLAN area, WLAM access points should have the capability of IEEE 802.1x-based user authentication and authorization functionality. In this paper, we provide a brief understanding of IEEE 802. 1x standards and related protocols likeEAPoL(Extended Authentication Protocol Over LAN), EAP, RADIUS and describe how the IEEE 802.1x is designed and implemented in our embedded linux-based WLAN AP which is named i-WiNG.(Intelligent Wireless Internet Gateway).

건축물 설계변수의 상관관계 분석을 통한 CO₂ 배출저감 방안

이현우,채민수,Lee, Hyun-Woo,Chae, Min-Su 한국태양에너지학회 2011 한국태양에너지학회 논문집 Vol.31 No.1

This study proposes a $CO_2$ emission reduction method through correlation analysis of a sample building. First, energy saving factors of heating, cooling, lighting were determined for the correlation analysis and $CO_2$ emission contribution rate of the design parameters have been analyzed. Then optimal combination of each design parameter has been drawn. Heat transfer coefficient of walls and windows, air permeability, windows area ratio, and shading devices were selected as applicable energy saving factors of the sample building. Also computer simulation was conducted using experimental design by Orthogonal Arrays of the statistical method. And the contribution rate was estimated by Analysis of Variance-ANOVA. As a result, the $CO_2$ emission in heating was reduced to 51.9%; in cooling to 16.8%; and in lighting to 2% compared to the existing building. The majority of the reduction was presented by heating energy.

연구논문 : 와이블과정을 응용한 신뢰성 성장 모형에서의 MTBF 추정

이현우,김재주,박성현 ( Hyun Woo Lee,Jae Joo Kim,S . H . Park ) 한국품질경영학회 1998 한국품질경영학회 학술대회 Vol.1998 No.12

주변 움직임 벡터의 적응적 선택을 이용한 효율적인 에러은닉 알고리즘

이현우,성동수,Lee Hyun-Woo,Seong Dong-Su 한국정보처리학회 2004 정보처리학회논문지B Vol.11 No.6

통신 기술의 발전으로 무선 채널을 이용한 멀티미디어 서비스를 제공하기 위한 방법이 활발히 연구되고 있다. 이에 따라 최근 무선망이나 인터넷과 같이 오류가 많이 발생하는 채널을 통한 비디오의 전송이 급격히 증가하면서 채널 상에서 발생하는 전송에러로 인한 데이터의 손실이 심각한 문제로 대두되고 있으며, 이에 따라 에러 은닉이 주된 관심사로 부각되었다. 에러 은닉 기법은 부가 정보가 필요 없으며, 부호화 기법의 변형 없이 적용이 가능하기 때문에 널리 연구되고 있다. 본 논문에서는, 손실된 블록 주위의 정상블록들 중 움직임 벡터들의 적응적 선택을 이용하여 중간 값을 취한 후, 손실된 블록의 새로운 움직임 벡터로 할당하고, OBMC(Overlapped Block Motion Compensation)을 통해 최종적으로 손실영역을 은닉하게 된다. 이 방법은 연속된 GOB(Group Of Block)의 손실에 있어서 효과적임을 알 수 있었다. 실험 결과 PSNR 성능평가 면에서 제안한 방법의 결과가 기존의 방법들 중 우수한 에러은닉 결과를 내는 MVRI(Motion Vector Rational Interpolation)이나 메디안$.$중첩 에러 은닉 기법에 비해 약 3db정도 향상된 결과를 얻을 수 있었다. In the wireless communication systems, transmission errors degrade the reconstructed image quality severely. Error concealment in video communication is becoming increasingly important because transmission errors can cause single or multiple loss of macroblocks in video delivery over unreliable channels such as wireless networks and internet. Among various techniques which can reduce the degradation of video quality, the error concealment techniques yield good performance without overheads and the modification of the encoder. In this paper, lost image blocks can be concealed with the OBMC(Overlapped Block Motion Compensation) after new motion vectors of the lost image blocks are allocated by median values using the adaptive selection with motion vectors of adjacent blocks. We know our algorithm is more effective in case of continuous GOB loss. The results show a significant improvement over the zero motion error concealment and other temporal concealment methods such as Motion Vector Rational Interpolation or Median+OBMC by 3dB gain in PSNR.

3G LTE and SAE

이현우,Lee Hyun-Woo 한국통신학회 2006 정보와 통신 Vol.23 No.6

거창 고학리 해주오씨의 장소애착을 통해 본 종족경관의 형성과정

이현우,Lee, Hyun-Woo 한국조경학회 2013 韓國造景學會誌 Vol.41 No.5

This research, which sought to conjecture the formation process of tribal landscape while confirming the method and characteristic of place attachment of the Haeju Oh Family, which is rooted within the village and the Yongwon Pavilion and Garden of Gohak-ri, Mari-myeon, Geochang-gun, Gyeongnam, reached the following conclusion based on the interpretation and analysis of cultural and scenic elements such as the names and sculptures nearby the village and Yongwon Pavilion and Garden. This place is where Goohwagong Oh Sue, a Haeju person, settled down. This is also where his descendants were refined while yearning for their ancestors. The Yongwon Pavilion was established in 1964. It can be sufficiently known that this place was managed and maintained as a garden-like place where the spirit of yearning was shared and which was the basis of the life and entertainment of descendants after being the monumental place for Master Oh Guhwa, through stories, documents, nearby facilities, and writings on many rocks. It is clear that the meaning of 'Bang-Hak(訪鶴) and Jung-Hak (停鶴)' which is carved in many places around this area and Gohak-ri, which symbolizes the Hakbong(crane peak), the vein of Wonjak-dong which is one of the Ahneuisamdong(three outstanding scenic places of Ahneui), is a scenic language explaining the ecological settlement and lives of the Haeju Oh Family. When considering the definition of a sense of place as "a 'social device' made by discussions and practice rather than its existing as a substance," the many structures scattered around the village, Yongwon Pavilion Garden, and nearby designations show the monumental place inheritance of tribal group clearly exhibiting the characteristics of a Korean sense of place. Ever since Guhwagon Oh Sue settled down in Guhak-ri, the tribal group of Haeju Oh Family went through a life settlement phase and landscape formation phase by realizing the sense of place. Afterwards, while yearning for ancestors and repeatedly rooting down in the place, territoriality expanded and the place was reproduced. In particular, timber houses and monuments were constructed during the Japanese Colonization Period, and after independence, the Yongwon Pavilion was constructed through place reproduction, and monumental tribal landscape is currently being expressed in various forms to this day. Thus, allowing to reach the conclusion of 'Tribal Landscape of Gohak-ri, Mari-myeong, Geochang-gun,' which we perceive today. The products of territorial expansion formed by the repeating phenomenon of place rootedness and place attachment by tribal groups are in fact the substance of tribal landscape. Through such, it is possible to confirm the true spirit of place attachment and the earnest interest and affection of descendants towards a unique place that is repeatedly constructed and inherited within the group memory. 경남 거창군 마리면 고학리에 소재한 용원정원림(龍源亭園林) 및 마을주변의 지명과 조형물 등 문화경관적 요소들에 대한 분석과 해석을 토대로 용원정원림과 마을 내 배태(胚胎)된 해주오씨의 장소애착 방식과 특질을 확인하는 한편, 종족경관(宗族景觀)의 형성과정을 추찰하고자 한 본 연구의 결론은 다음과 같다. 해주인 구화공 오수(九華公吳守)가 마을에 터 잡은 이래 그의 후손들이 선조를 사모하는 마음으로 다듬어 온 공간으로 1964년 용원정이 건립되었다. 이곳은 구화공의 유허지로 이후 후손들의 생활과 풍류의 거점이자 숭모(崇慕)의 정을 교감하는 원림적 장소로서 지속적으로 관리되어 왔음이 기문과 문헌자료 그리고 주변에 배치된 여러 시설 및 다수의 바위에 새긴 바위글씨를 통해서도 충분히 감지된다. 안의삼동 중 하나인 원학동의 지맥인 학봉(鶴峰)을 상징하는 고학리와 이곳에 각인된 '방학(訪鶴) 정학(停鶴)'의 의미는 해주오씨의 생태적 정착과 서식을 설명하는 경관언어가 분명하다. 장소성이 "어떤 실체로서 존재하기 보다는 담론과 실천에 의해 만들어지는 사회적 고안물이다"라는 정의를 상기할 때, 주변 지명과 용원정원림 그리고 마을 도처에 산재한 다수의 조영물은 한국적 장소성의 특성을 일목요연하게 보여주는 종족집단의 기념비적 장소 전승의 사례이다. 구화공이 고학리에 정착한 이래 해주오씨 종족집단은 서식지 정착단계를 거쳐 장소성 구현을 통한 경관형성단계를 이루었다. 이후 조상숭모와 장소착근 현상이 되풀이되면서 영역성은 확산되고, 장소의 재생산이 이루어졌다. 특히 일제강점기에도 재실 건립과 유허비 조성 등이 이어졌으며, 해방 이후에도 용원정 건립 등 장소재현의 단계를 거쳐 현재까지도 다양한 형태의 기념비적 종족경관이 펼쳐지고 있으며, 이러한 장소애착(場所愛着)과 장소착근(場所着根)의 결과가 바로 우리가 지각하는 '거창군 마리면 고학리의 종족경관'이라는 결론에 도달하게 된다. 종족집단의 장소애착과 장소착근의 현상이 되풀이되어 형성된 영역성 확산의 산물이야말로 종족경관의 실체인 것이다. 이를 통해 우리는 집단 기억 속에 재차 구축 전승되고 있는 고유한 장소에 대한 후손들의 진지한 관심과 사랑 그리고 진정한 장소애착의 정신을 확인하게 된다.