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.

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.

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.

보호구간이 없는 OFDM-CDMA 시스템의 성능 향상 기법

이현우,박중후,Lee Hyun-Woo,Park Joong-Hoo 한국통신학회 2006 韓國通信學會論文誌 Vol.31 No.5a

보호구간이 없는 Orthogonal Frequency Division Multiplexing-Code Division Multiplexing Access(OFDM-CDMA) 시스템을 사용하면 보호구간이 있는 OFDM-CDMA 시스템보다 대역폭 효율을 향상시킬 수 있다. 보호구간이 없는 OFDM-CDMA 시스템에서 Inter-Symbol Interference(ISI)와 Inter-Carrier Interference(ICI)를 제거하는 새로운 기법을 제안한다. 제안된 알고리즘은 Pseudo-Decorrelator에 기초하는 보호구간이 없는 OFDM-CDMA 시스템의 복조 기법이며, PD 알고리즘이라고 부르기로 하자. 모의실험 결과는 PD 알고리즘이 보호구간이 없는 OFDM-CDMA 시스템에서 ISI와 ICI를 효과적으로 제거할 수 있음을 보여준다. PD 알고리즘은 기존의 보호구간이 없는 OFDM-CDMA 시스템보다 좋은 BER 성능을 나타낸다. Orthogonal frequency division multiplexing-code division multiplexing access(OFDM-CDMA) systems without guard interval can enhance the bandwidth performance more efficiently than the systems with guard interval. In this paper, a new technique for an OFDM-CDMA system without guard interval, which can eliminate inter-symbol interference(ISI) and inter-channel interference(ICI), is presented. The proposed algorithm is a new demodulation technique, based on the Pseudo-Decorrelator, and it is named PD algorithm. Simulation results show that the PD algorithm can combat ISI and ICI efficiently for an OFDM-CDMA system without guard interval. The BER performance of the PD algorithm is much better than that of a conventional OFDM-CDMA system without guard interval.

USN에서 중간 노드에서의 보고서 검증 시도 확률 평가 함수를 이용한 에너지 효율 향상 기법

이현우,문수영,조대호,Lee, Hyun-Woo,Moon, Soo-Young,Cho, Tae-Ho 한국시뮬레이션학회 2011 한국시뮬레이션학회 논문지 Vol.20 No.4

무선 센서 노드들은 개방된 환경에서 동작하기 때문에 외부의 물리적인 공격에 매우 취약하다. 공격자는 노드들을 훼손시켜서 센서 네트워크에 허위 보고서를 주입시킬 수 있다. 이러한 공격들은 센서 노드들의 에너지를 고갈시킨다. 이에 대응하는 보안 기법으로 Ye등은 중간 노드가 일정한 확률로 보고서를 검증하는 통계적 여과 기법을 제안하였다. 통계적 여과 기법은 모든 중간 노드가 같은 확률로 보고서 검증을 수행한다. 따라서 정상 보고서와 허위 보고서를 검증하는데 같은 에너지가 소모 되므로 정상 보고서를 검증하는데 불필요한 에너지를 소모하게 된다. 본 논문에서는 각 중간 노드가 보고서 검증 시도 확률을 조절하여 센서 노드들의 에너지 소모량을 줄이는 기법을 제안한다. 보고서 검증 시도 확률은 한 노드의 잔여 에너지양, 현재 노드에서 기지 노드까지의 홉 수, 허위 보고서의 비율에 의해 결정된다. 보고서 검증 시도 확률을 조절하여 통계적 여과 기법과 비슷한 보안성을 유지하면서 에너지의 효율성을 높일 수 있다. Wireless sensor nodes operate in open environments. The deployed sensor nodes are very vulnerable to physical attacks from outside. Attackers compromise some sensor nodes. The compromised nodes by attackers can lead to false data injection into sensor networks. These attacks deplete the limited energy of sensor nodes. Ye et al. proposed the Statistical En-Route Filtering (SEF) as a countermeasure of the attacks. The sensor node in SEF examines the event reports based on certain uniform probability. Thus, the same energies are consumed in both legitimate reports and false reports. In this paper, we propose a method that each node controls the probability of attempts to verify a report to reduce energy consumption of sensor nodes. The probability is determined in consideration of the remaining energy of the node, the number of hops from the node to SINK node, the ratio of false reports. the proposed method can have security which is similar with SEF and consumes lower energy than SEF.

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

오우크쇼트의 ‘시민성’(civility) 개념과 시민교육적 함의

차미란(Cha, Mi-Ran) 한국도덕윤리과교육학회 2021 도덕윤리과교육 Vol.- No.73

2015 개정 도덕과 교육과정에서 도덕과 교육의 지향점으로 제시된 ‘도덕적인 인간과 정의로운 시민이라는 중첩된 인간상’은 인간과 시민의 구별, 인성교육과 시민교육의 관계에 관한 해명을 요청한다. 본 연구는 오우크쇼트의 정치철학과 정치교육론을 중심으로, 루소가 『에밀』에서 제시하는 ‘자연인’으로서의 인간과 ‘사회인’으로서의 시민 사이의 대비를 해석하고, 인간교육과 시민교육의 모순적 관계를 해소하는 대안적 관점을 모색해보고자 하였다. 근대 국가의 성격을 설명하는 두 가지 결사체 형태로서의 ‘시민적 결사체’와 ‘기업적 결사체’, 그 두 가지 결사체에 각각 상응하는 ‘시민’과 ‘대중’의 구분에 관한 오우크쇼트의 논의는 ‘시민성’개념이 ‘개인성’에 기반을 두고 있다는 점을 보여 준다. 오우크쇼트의 정치교육론에 따르면, 모든 진정한 교육은 개별적 인간의 내면에 인간다움과 도덕성을 갖추도록 하는 인성교육인 동시에 시민적 결사체의 정당한 구성원으로서의 자질을 갖추도록 하는 시민교육이다. 훌륭한 시민은 획일화된 대중이 아니라 지성과 자율성을 갖춘 주체적 개인이라는 점에서, 정의로운 시민을 기르기 위한 시민교육은 진정한 ‘개인성’을 함양하는 교육이어야 한다. 특히, 기업적 결사체로서의 국가에서 시행되는 ‘시민교육’이 다수의 이익 실현에만 관심을 두는 ‘대중’을 양성할 위험에 대한 오우크쇼트의 경고는 심각한 의미를 가진다. The ‘overlapping ideals of a moral human being and a righteous citizen’, presented as the direction for moral studies education in the 2015 revised moral education curriculum, asks for an explanation of the distinction between humans and citizens and the relationship between character education and civic education. This study is an attemt to find an alternative perspective that resolves the contradictory relationship between negative education for ‘human’ as natural being and positive educstion for ‘citizen’ as social being in Rousseau’s 『Emile』, focusing on Oakeshott"s political philosophy and his views on political education. Oakeshott"s discussion on the distinction between ‘cive’ and ‘mass’ corresponding to the two associations, ‘civil association’ and ‘enterprise association", as two forms of association explaining the nature of the modern state, shows that the concept of ‘civility’ is based on ‘individuality’. According to Oakeshott"s views on political education, all true education is character education that equips each individual with humanity and morality, and at the same time, civic education that enables them to qualify as just members of a civil association. Since a good citizen is not one of mass but a free individual with intelligence and morality, civic education to raise righteous citizens should be an education cultivating ‘individuality’. In particular, we need to take Oakshott"s warning seriously that ‘citizenship education’ implemented in the state as an enterprise association could result in nurturing the ‘mass man’ who only cares about the realization of the common interests of the majority.

A Case of Globus Hystericus caused by psychological, digestive disorder

이현우,장유진,홍승욱,Lee, Hyun-Woo,Chang, You-Jin,Hong, Seung-Ug The Society of Korean Medicine Ophthalmology 2013 한방안이비인후피부과학회지 Vol.26 No.2

Objectives : 본 연구를 통해 정신과적, 소화기성으로 유발된 히스테리성 구를 반하백출천마탕과 자음건비탕으로 치료한 1례를 보고하려 한다. Methods : 오심, 불면, 이명, 소화불량, 초조, 두통, 매핵기를 주소로 하는 23세 여성 환자를 대상으로 약 4개월 동안 침구, 반하백출천마탕과 자음건비탕으로 치료하였다. Results & Conclusions : 4개월 동안의 치료 후, 히스테리성 구와 다른 증상들이 소실되었다. 이 논문에서는, 소화기계 장애와 정신 질환 치료를 위해 오랫동안 사용되어온 반하백출천마탕과 자음건비탕을 히스테리성 구 치료에 이용하였다. 결론적으로, 본 연구는 히스테리성 구와 소화기계 장애가 밀접한 관련이 있음과 히스테리성 구에 대한 한의학적 치료의 중요성을 제시하였다.

순도에 따른 Al 판재의 재결정 거동

이현우,하태권,박형기,민석홍,Lee, Hyun Woo,Ha, Tae Kwon,Park, Hyung-Ki,Min, Seok-Hong 한국재료학회 2016 한국재료학회지 Vol.26 No.12

Recrystallization behavior has been investigated for commercial purity AA1050 (99.5wt%Al) and high purity 3N Al (99.9wt% Al). Samples were cold rolled with 90% of thickness reduction and were annealed isothermally at 290, 315, and 350o C for various times until complete recrystallization was achieved. Hardness measurement and Electron Backscatter Diffraction(EBSD) analyses, combined with Grain Orientation Spread(GOS), were employed to investigate the recrystallization behavior. EBSD analysis combined with GOS were distinctly revealed to be a more useful method to determine the recrystallization fraction and to characterize the recrystallization kinetics. As the annealing temperature increased, recrystallization in AA1050 accelerated more than that process did in Al 3N. Both AA1050 and Al 3N showed the same temperature dependence of the n value of the Johnson-Mehl-Avrami-Kolmogorov equation(JMAK equation), i.e., n values increased as annealing temperature increased. Activation energy of recrystallization in AA1050 is about 176 kJ/mol, which is comparable with the activation energy of grain boundary migration in cold-rolled AA1050. This value is somewhat higher than the activation energy of recrystallization in Al 3N.