2-프로핀일 고리 카보네이트의 Pd(0) 촉매를 이용한 가수소분해반응연구 : (Z)-호모알릴알콜과 2-호모프로핀일 알코올의 합성 Catalyzed Hydrogenolysis of Prop-2-ynylic Cyclic Carbonates

강석구,박동철,정재욱,정경윤 성균관대학교 기초과학연구소 1994 論文集 Vol.45 No.1

삼중 결합을 갖고 있는 2-프로핀일 고리카보네이틀 Pd(acac)_2와 nBu_3P을 촉매로 하여 포름산 암모늄염을 사용한 탈카르복실화-가수소분해반응을 이용해서 (Z)-호모알릴 알콜과 2-호모프로핀일 알콜을 반응조건에 따라 각각 합성하였다. 그리고 분자끝 2-프로핀일 고리카보네이트의 가수소분해반응을 이용하여 호모알릴 알콜을 합성하였다. (2S. 4Z)-1-(p-메톡시벤질옥시)-2-히드록시-4-헵틴 2b를 광학활성 중간체로 사용하여 pyralid 나방 Aphomia gularis의 male 성페르몬을 합성하였다. The decarboxylation-hydrogenolysis of prof-2-ynylic cyclic carbonates which have an internal acetylenic bond with ammonium formate in the presence of a catalytic amount of [Pd (acac)_2] and nBu_3P afforded(Z)-homoallylic alcohols or homoprop-2-ynylic alcohols dependin on the reaction conditions. however, hydrogenolysis of terminal prop-2-ynylic cyclic carbonates gave homoallylic aicohols; using (2S, 4Z)-1-(p-Methoxybenzyloxy)-2-hydroxy-4-heptyne 2b as a chiral synthon, the male sex pheronome of the pyralid moth Aphomia gularis has been synthesized.

초등학교 과학수업에서 교사의 학습 동기 전략 분석

김동욱,이성숙,강대훈,백성혜 한국초등과학교육학회 2004 초등과학교육 Vol.23 No.1

The purpose of this study was to define teachers' learning motivation strategies and students' responses by analyzing science classes and interviews. The subjects were first grade and sixth grade teachers and students of an elementary school. The analysis tools are based on Keller's ARCS theory. The differences of teachers' motivation strategies were analyzed by grades and teachers' and students' backgrounds. The interviewers were composed of three teachers and three students of first grade, and three teachers and three students of sixth grade. The data were collected by recording of the classes using tape recorders, video cameras, and notebooks written by researchers. The results are as follows. First, teachers had their own styles of teaching strategies in their classes. Especially teachers' teaching backgrounds affected on the teachers' instructional strategies. The teachers who had long teaching experiences of lower grade students used to show a lot of attention strategies. While the teachers with long teaching experiences of higher grade students used to show few learning motivation strategies. Especially, sixth grade teachers used to show fewer confidence strategies than first grade teachers. Second, all of the teachers used to show few satisfaction strategies commonly in all the classes observed. Third, the students' recognition of the motivation strategies were not different according to their conceptions or activities of the classes. Commonly first grade students focused on the attention strategies, while sixth grade students focused on negative motivation strategies. Fourth, the teachers who believed that students need detail guidance and control recognized the needs of satisfaction strategies by students' autononmous activities after observing video tapes of other teachers' classes.

지하주차장의 조명제어 시스템 설계 및 구현

신동욱,강승찬 한국기술교육대학교 2000 論文集 Vol.7 No.1

This paper presents the lamp control system in underground parking place. The control system consists of lamp control modules and monitoring module which are connected by RS-485 communication bus. The lamp control modules are controlled through a user command within the monitoring module, sense a movement detector and turn lamps in underground parking place on or off. The monitoring module displays status values of On or Off received from lamp control modules. The system is an efficient lighting control system to meet today's demand for highly flexible and energy saving lighting solutions.

오스테나이트계 스테인리스강의 진동감쇠능에 미치는 ε 마르텐사이트의 영향

손동욱,김재환,김익수,Miyahara Kazuya,성장현,강창룡 대한금속재료학회 2004 대한금속·재료학회지 Vol.42 No.8

The effect of the phases of y, α' and ε martensites, which constitute the structure of the 316L stainless steel with austenite structure at room temperature, on the damping capacity at room temperature has been investigated. As a result, various fractions of these phases were formed depending on the degree of cold work. The largest volume fraction of a martensite phase is obtained by 20% cold rolling and showed the highest damping capacity. The damping capacity is strongly controlled by the volume fraction of ε martensite with linear relationship, while the other phases of α' and r have actually no effect on the damping capacity.

FDTD를 이용한 인체 두부모델의 SAR 분포특성 해석

홍동욱,김두현,강동규 한국안전학회 2004 한국안전학회지 Vol.19 No.2

This paper presents an analysis of SAR(Specific Absorption Rate) distribution characteristics in a head model using FDTD(Finite Difference Time Domain). In this study human head was modelled in four elements-layered structure, consisting of skin, fat, skull and brain. To calculate the electromagnetic fields wihtin the head model, FDTD method was used In the FDTD method, the electromagnetic wave is analyzed by solving a Maxwell's equations repeatedly. For the calculation, distance between power source and head model increased by 10[m]. Power density and incident electric field intensity were calculated Based on the incident electric field, the program which calculate internal electric fields intensity and SAR calculation of the head model were developed The results of developed program using FDTD were compared with those of a commercial programs, which showed the availability and usefullness of the suggested scheme in this paper

유자 중 limonoid 화합물의 정량 및 분리정제에 관한 연구

우강용,하정욱,우동균 慶南大學校 附設 工業技術硏究所 1997 硏究論文集 Vol.15 No.1

남해안에서 생산되는 유자의 씨와 과피중의 limonoid 함량을 HPLC (Spectra Physics 8800, U.S.A)에 의하여 분석 정량해 보았다. Limonoid 화합물 중 limonin과 nomilin은 methanol과 acetone에 의해 비교적 추출이 용이하였으며, acetone과 acetonitrile에 의해서 naringin이 거의 추출되지 않았으나 methanol에 의해서는 상당히 많은 양이 추출되었다. 유자씨에는 107.4mg%의 limonin과 85.39mg%의 nomilin이 함유되어 있으나, 유자 과피중에는 0.05mg%의 limonin과 0.034mg%의 nomilin이 함유되어 있었다. Amberite XAD-2 칼럼상에서 naringin 이 초기에 용출된 다음 100∼150㎖ 사이에서 limonin이 그리고 200∼250㎖ 사이에서 nomilin이 각가 최대의 용출율을 나타냄으로서 limonin과 nomilin의 분리정제 가능성이 확인되었다. Seeds and sarcocarp of citron from the southern part of Korean peninsula were analyzed for limonoid content by HPLC (Spectra Physics 8800, U.S.A) with the Nova-pak C18 column. Limonin and nomilin were well extracted by methanol and acetone, respectively, and little naringin was extracted by acetone or acetonitrile, but extracted in great quantity by methanol. Citron seeds contained 107.4 mg% of limonin and 85.39 mg% fo nomilin, and citron sarcocarp had 50 ppm of limonin and 34 ppm of nomilin. On the Amberite XAD-2 column naringin was elured at first, and then limonin and nomilin were eluted between 100㎖ and 150㎖, and between 200㎖ and 250㎖, respectively.

지면판위 복수 장애물 주위 유동장의 가시화(Ⅰ)

이동환,송창수,강경욱 울산대학교 1991 공학연구논문집 Vol.22 No.2

地面板위에 모양이 서로 다른 복수 장애물을 바람의 방향과 수직으로 배열(Side-Side)하여 액체4염화 티타늄을 관찰대상 표면에 직접 도색하여 유동장을 효과적으로 가시화 하였다. 장애물 사이의 간격이 좁아지면 틈을 통과하는 흐름은 어느 한쪽으로 傾斜진다는 특징이(Biased Flow) 확인되었고, 지면판위 박리선, Necklace Vortex, 후류등 3차원 유동장 특징이 확인되었다. Flow patterns around two-bluff bodies in side-by-side arrangements on the ground plane are easily visualized using liquid titanium tetrachloride. In two-dimensional flow field, the gap flow between two-bodies became biased to one side for closer spacing. Three-dimensional flow patterns, which have seperated regions, necklace vortices and other dynamic seperations, are dependant on the bluff-body shape and the gap-space ratio.

MWPC 위치검출기의 X-선 천체물리학에의 응용

남욱원,최철성,문신행,강희동 경북대학교 센서기술연구소 1990 센서技術學術大會論文集 Vol.1 No.1

1983 년경 국내에서도 과학탐사 로케트와 인공위성이 발사될 예정에 있으며 이에 따라 X-선 천체물리학을 위한 방사선 센서의 국내 개발이 시급히 요청되는 바이다. 따라서 현재 방사선계측에 많이 이용되고 있는 방사선 센서들 중 국내에서 개발되어온 MWPC위치검출기를 소개하고 인공위성 혹은 과학탐사로케트에 탑재되어 X-선 천체물리학연구에 이용될 경우 연구 개발되어 나가야 할 방향을 제시하고자 한다. Domestic sounding rocket and scientific satellite are scheduled to launch around 1993. The development of radiation sensor is required to observe X-rays coming from celestial bodies by the use of those space vehicleS. In this study we introduce the multi-wire position sensitive detector and the future works of onboard detector for X-ray astrophysics.

양방향 링크를 갖는 개선된 DSR Ad Hoc 라우팅에 관한 연구

김현욱,이광배,김정일,최동근 명지대학교 산업기술연구소 2001 産業技術硏究所論文集 Vol.20 No.-

In this paper, we enhanced the existing DSR routing protocol for ad hoc networks with bidirectional link. In mobile ad hoc network, mobile nodes themselves have router capability. Thus, for communication between two mobile nodes, the routing protocol for route set-up is required. DSR routing protocol, which is one of famous mobile ad hoc routing protocols, has the following problem: when route error occurs, the sending data packets drop as route recovery is delayed. In order to alleviate such problem, we modified route maintenance process of the existing DSR protocol so that the route recovery time from route error was shortened. As the result of performance evaluation, it was found the route recovery time of the proposed routing protocol was about 12 times faster than that of the existing DSR protocol. In addition, the data reception rate was more than 90 % for mobile ad hoc networks with slow mobility.

뇌출혈이 합병된 감염성 심내막염 1례

박동건,이재욱,권삼,이동철,강승완 동국대학교 경주대학 1997 東國論集 Vol.16 No.2

감염성심내막염에 의한 신경계 합병증은 색전성 뇌경색, 색전성 뇌출혈, 두개내 패혈성 동맥류, 뇌농양, 뇌막염등 다양한데 항생제 요법의 발달과 판막치환술에도 불구하고 그 빈도는 감소되지 않고 있다. 이 중 두개내 패혈성 동맥류의 파열에 의한 뇌출혈은 사망률이 80%로 치명적일 수 있어 조기 발견 및 적절한 치료가 필요하다. 저자들은 두통, 열감, 근육통 등의 증상으로 내원하여 감염성 심내막염으로 진단받고, 항생제 치료로 임상증세의 호전중에 심한 두통과 전신적 발작이 있은 후 갑자기 발생한 두개내 뇌출혈을 심장초음파 및 뇌 컴퓨터 단층촬영을 통하여 진단, 경험하였기에 문헌고찰과 함께 보고하는 바이다. The complications of infective endocarditis may involve any organ system ie, cardia, neurologic, vascular, dermatologic, and kidney. Extracardiac complications are usually caused by either embolization of vegetations or deposition of immune complexes. Neurologic complications remain a significant problem in bacterial endocarditis and have been reported to occur in up to 20% to 40% of cases of infective endocarditis. The various types of central nervous system disease seen in patients with infective endocarditis are cerebral embolism (with infarction or with intracerebral hemorrhage), intracranial mycotic aneurysm, seizures, brain abscess, meningitis, mental change, psychiatric disorder. Mycotic aneurysms are uncommon but not rare and are an important cause of local or systemic sepsis and acute hemorrhage following aneurysmal rupture. Cerebral mycotic aneurysms have been noted in 2∼10% of cases of bacterial endocarditis and account for 2.5∼6.2% of all intracerebral aneurysms. We have experienced a case of neurologic complication due to infective endocarditis in a 23 year-old female patient, who admitted to our hospital because of fever, chill, headache, myalgia. This case was diagnosed by echocardiography, brain computed tomography. The patient died of sudden intracerebral hemorrhage in the 53th hospital day despite intensive medical treatment. We report one case of intracerebral hemorrhage complicated with infective endocarditis.