신규 제초제 후보물질 M-862의 광엽잡초에 대한 제초활성

구대원(Dae-Won Koo),조남규(Nam-Gyu Cho),황기환(Ki-Hwan Hwang),구석진(Suk-Jin Koo),박기웅(Kee Woong Park) 한국잡초학회 2019 한국잡초학회 별책(학술대회 초록집) Vol.39 No.2

고전압 GaN 쇼트키 장벽 다이오드의 완충층 누설전류 분석

황대원(Dae Won Hwang),하민우(Min-Woo Ha),노정현(Cheong Hyun Roh),박정호(Jung Ho Park),한철구(Cheol-Koo Hahn) 大韓電子工學會 2011 電子工學會論文誌-SD (Semiconductor and devices) Vol.48 No.2

본 논문에서 실리콘 기판 위에 성장된 GaN 에피탁시를 활용하여 고전압 쇼트키 장벽 다이오드를 제작하였으며, 금속-반도체 접합의 열처리 조건에 따른 GaN 완충층 (buffer layer) 누설전류와 제작된 다이오드의 전기적 특성 변화를 연구하였다. Ti/Al/Mo/Au 오믹 접합과 Ni/Au 쇼트키 접합이 제작된 소자에 설계 및 제작되었다. 메사를 관통하는 GaN 완충층의 누설전류를 측정하기 위하여 테스트 구조가 제안되었으며 제작하였다. 700℃에서 열처리한 경우 100 V 전압에서 측정된 완충층의 누설전류는 87 ㎁이며, 이는 800℃에서 열처리한 경우의 완충층의 누설전류인 780 ㎁보다 적었다. GaN 쇼트키 장벽 다이오드의 누설전류 메커니즘을 분석하기 위해서 Auger 전자 분광학 (Auger electron spectroscopy) 측정을 통해 GaN 내부로 확산되는 Au, Ti, Mo, O 성분들이 완충층 누설전류 증가에 기여함을 확인했다. 금속-반도체 접합의 열처리를 통해 GaN 쇼트키 장벽 다이오드의 누설전류를 성공적으로 감소시켰으며 높은 항복전압을 구현하였다. We have fabricated GaN Schottky barrier diode (SBD) for high-voltage applications on Si substrate. The leakage current and the electrical characteristics of GaN SBD are investigated by annealing metal-semiconductor junctions. Ohmic junctions of Ti/Al/Mo/Au and Schottky junctions of Ni/Au are used in the fabrication. A test structure is proposed to measured buffer leakage current through a mesa structure. When annealing temperature is increased from 700℃ to 800℃, measured buffer leakage current is also increased from 87 ㎁ to 780 ㎁ at the width of 100 ㎛. The diffusion of Au, Ti, Mo, O into GaN buffer layer increases the leakage current and that is verified by Auger electron spectroscopy. Experimental results show that the low leakage current and the high breakdown voltage of GaN SBD are achieved by annealing metal-semiconductor junctions.

물사마귀에 의한 운륜 현상 1예

김동하 ( Dong Ha Kim ),구대원 ( Dae Won Koo ),이혜경 ( Hye Kyung Lee ),정경은 ( Kyung Eun Jung ),이중선 ( Joong Sun Lee ) 대한피부과학회 2016 大韓皮膚科學會誌 Vol.54 No.8

Halo nevi (HN), also known as Sutton’s nevi or leukoderma acquisitum centrifugum, are nevomelanocytic nevi surrounded by a rim of depigmentation. A 9-year-old female presented with an asymptomatic solitary flesh-colored 0.75-cm-sized papule surrounded by depigmentation on the right cheek 1 month ago. The excisional biopsy demonstrated molluscum contagiosum and decreased basal layer pigmentation on Fontana Masson stain. The halo phenomenon is often associated with an acquired nevus cell nevus, but has also been associated with a congenital nevus cell nevus, non-neuroectodermal lesions such as angiomas, seborrheic keratoses, lichen planus, sarcoid, psoriasis, involuting flat warts, and histiocytoma. Our patient had an unusual association of molluscum contagiosum with the halo phenomenon. We suppose that the halo phenomenon in this patient might have been provoked by the molluscum contagiosum virus. A halo nevus-like appearance suggests the possibility of disease other than nevus. In such cases, skin biopsy is required for confirmation. (Korean J Dermatol 2016;54(8):638∼641)

대용량 위성영상의 무감독 분류를 위한 병렬처리 구현

구인회(In-Hoi Koo),한수희(Soohee Han),이선구(Sun-Gu Lee),정대원(Dae-Won Jung) 한국항공우주학회 2016 한국항공우주학회 학술발표회 논문집 Vol.2016 No.11

영아 급성 출혈성 부종

이윤정(Yun Jeong Lee),구대원(Dae Won Koo),박천욱(Chun Wook Park),이철헌(Cheol Heon Lee) 대한피부과학회 1994 대한피부과학회지 Vol.32 No.2

Infantile acute hemorrhagic edema is a benign disease followed by a spontaneous eomplete recovery without sequelae, characterized by cockade purpura and inflamrntory edema on the face and extremities without any internal origin involvement in 4-month to 2-year-old infants. We report a case of infaniile acute hemorrhagic edema which occared in a 2-year-old female after an upper respiratory illness and compare the clinical and histologic features of this disorder with Henoch-Schonlein purpura. (Kor J Dermatol 1994; 32(2): 332-336)

부분적으로 다른 물성치를 갖는 단순보의 진동해석

배승훈(Seung-Hoon Bae),조대원(Dae-Won Cho),김대환(Dae-Hwan Kim),구정모(Koo Jung Mo),정의봉(Weui Bong Jeong),조진래(Jin Rae Cho) 한국소음진동공학회 2017 한국소음진동공학회 학술대회논문집 Vol.2017 No.4

춘천 및 강원도 북부지역의 대상포진 환자에 대한 통계적 고찰 ( 1994 - 1996 )

신덕용 ( Deok Yong Shin ),구대원 ( Dae Won Koo ) 대한피부과학회 1998 大韓皮膚科學會誌 Vol.36 No.3

Baekground: Herpes zoster is a relatively common dermatological disease and there have been several reports on the epidemiological study of herpes zoster in Korea. However there has not been any report on the epidemiology of herpes zoster in Chuncheon and the Northern Kangwon Province. Objective : The purpose of this study was to elucidate the epidemiological characteristics of herpes zoster in Chuncheon and the Northern Kangwon Province. Methods : The authors evaluated about 461 cases of herpes zoster with retrospective methods with regard to annual, monthly and seasonal incidences, age, sex ratio, associated conditions, anatomical distribution and complications at the department of dermatology in Chuncheon Sacred Heart Hospital, Hallym University during a 3 - Year-Period from Jan. 1994 to Dec. 1996. Results : The annual incidence of herpes zoster in new patients from our dermatology clinic ranged from 4.3% to 4.8%(mean 4.5%), and the ratio of male to female was 1:1.12. The peak incidence of monthly and seasonal analysis was in December and in the Fall. The majority of cases occurred most frequently over the 6th decade. The most common anatomical distribution of herpes zoster inpatients(211 cases) was thoracic dermatome(52.9%), followed by the ophthalmic branch of the trigeminal nerve(17.0%), cervical(13.6%), lumbar(6.3%), sacral(4.4%), maxillary branch of the trigeminal nerve(3.9%) and two different dermatomes (2.8%). Associated conditions of herpes zoster inpatients(211 cases) were observed in 108 patients (51.2%); hypertension(31.9%), gastritis(15.1%), diabetes mellitus(11.8%), hepatitis(9.2%), malignancy (8.4%), tuberculosis(4.2%), and so on. The complications including postherpetic neuralgia were observed in 58 patients(27.5%) and were common after the age of 50 years. The rnost common complication of herpes zoster inpatients(211 cases) was postherpetic neuralgia(14.7%), followed by ophthalmologic complications(8.1%), secondary bacterial infections(1.4%), neurogenic bladder(1.4%), otologic complications(0.9%), and so on. Conclusion: Most of the other results of our study were similar in comparison with reports from other regions in Korea, except for a higher annual incidence and significant differences in the monthly incidence. These differences reflected the regional characteristics of medical service delivery systems in Chuncheon and the Northern Kangwon Province. (Korean J Dermatol 1998;36(3): 422-429)

아토피 피부염 환자에서 집먼지 진드기에 대한 제1형 알레르기 반응과 호흡기 아토피의 가계적 배경에 관한 연구

신자경 ( Ja Kyoung Shin ),구대원 ( Dae Won Koo ),이종주 ( Chong Ju Lee ),장완섭 ( Yean Sub Jang ) 대한피부과학회 1995 대한피부과학회지 Vol.33 No.6

Background : Recent studies have suggested that house dust mite allergy is an important cause of the atopic dermatitis(A.D). However, it is not clear that. what factors may be related to the development of the mite illergy in patients with AD. Objective : This study was done to see whether the presence of a familial background of RA implies a relationship to the mite allergy in AD. Methods : Skin prick test and fluoroallergosorbent, test (FAST) with house dust mit,e were performed in 47 patients wih AD. Results : 1. In comparison the esult of prick test with that of FAST to house dust mite antigen, it showed a concordance ra!e of 82%. And the prick test was more sensitive than the FAST. 2. The prevalence of positive FAST reactions was significantly increased in the patients with AD who had a family hitory of RA than those in patients with AD who had neither family or personal history of RA. 3. The level of specific IgE against house dust mite did not relate to the presence of family cr personal history of RA. 4. The prevalence of positive prick test results did not relate to the presence of family or personal history of RA. 5. The prevalence of positive FAST reactions, the level of specific IgE, and the rate of positive prick test results did not relate to the severity of skin involvement. 6. The most common allergens which caused positive skin reactions were house dust, cat fur, Dermatophagoides farinac, Dermatophagoides pteronyssinus, et al. Antigen score of prick test to 55 common antigens wa. significant increased in the patients with AD who had a family history of RA, but did not relat to the severity of skin involvement or the presence of personal history of RA. Conclusion : We may conclude that type I allergy to the house dust mit,e is not directly related to AD perse. This type of allergy to the mite seems to occur predominantly in those patient s with AD who have a farilial background of RA. (Kor J Dermatol 1995;33(6): 1046-1052)

기저 세포암에 대한 5 - Fluorouracil 병변내 주입의 치료 효과

이윤정(Yun Jeong Lee),구대원(Dae Won Koo) 대한피부과학회 1994 대한피부과학회지 Vol.32 No.2

Basal cell carcinomas(BCCs) are usually treated with ablative proccdures, but a nonsurgical treatment would conserve tissue and obtain a better cosmetic out come as well as treat patients who refuse surgery or those who are not good surgical candidates. Because of inadequate drug penetration, low cure rates, high recurence rates, and adverse reactions, such as contact dermatitis, topical 5-fluorouracil(5-FU) is unsaitble to treat nodular BCCs. But, int,ralesional 5-FU has been reported to be effective for nodular BCCs. The efficacy and safety of intralesional injection of 5-FU have been evaluated for treatment of BCCs. The results revealed that intralesional injection of 5-FU seems to be effective in the treatment of various premalignant and malignant skin lesions as well as BCCs without side effects. (Kor J Dermatol 1994; 32(2): 337-341)

국내 암석의 암종별 열물성 특성 분석

차장환(Cha, Jang-Hwan),명대원(Myoung, Dae-Won),구민호(Koo, Min-Ho),송윤호(Song, Yoon-Ho),김형찬(Kim, Hyeng-Chan) 한국신재생에너지학회 2007 한국신재생에너지학회 학술대회논문집 Vol.2007 No.11

본 연구에서는 국내 암석을 암종별로 총 292개 채취하였으며 열물성 측정 장비를 이용하여 이들 암석의 열물성을 측정하였다. 이와 더불어 암석의 물리적 특성을 측정하였으며 일부 시료의 경우 XRD 정량분석을 실시하였다. 이들 결과를 이용하여 암석의 열물성 특성과 열물성에 영향을 주는 인자를 파악하였다. 암석의 열물성 측정 결과 열전도도와 열확산계수는 화강암에서 가장 낮은 값을 보였으며 퇴적암, 변성암 순으로 나타났다. 또한 암종별 열물성 값의 범위를 살펴보면 변성암과 퇴적암에서 넓게 분포한다. 암석의 물성과 열물성과의 상관성 분석 결과 공극률이 증가함에 따라 열전도도와 열확산계수가 감소하나 상관성은 미약한 것으로 나타났다. XRD 분석 결과 암석의 열전도도는 석영(SiO₂)의 함량에 따른 선형의 비례관계를 보였다. 이로써 암석의 열전도도는 암석을 이루는 광물의 종류에 의하여 영향을 받음을 알 수 있다. 차후 암석의 구성 광물입자의 배열 상태에 따른 열물성 특성과 퇴적암 및 변성암 시료에 대한 이방성 실험을 통해 편리, 층리 및 엽리 등에 따른 열물생의 이방성 정도를 분석할 예정이다.