Concise and efficient synthesis of two biologically active compounds using ring-closing olefin metathesis(RCM) as a key step

이우화 이화여자대학교 대학원 2001 국내석사

본 연구에서는 key step으로 ring-closing olefin metathesis(RCM)을 이용하여 biological activity를 갖는 두 화합물을 합성하였다. Part A에서는 dimethyl L-tartrate를 출발 물질로 7단계를 거쳐서 (+)-3,6-di-O-methyl protected conduritol-E를 총 26%의 수득률로 합성하였다. conduritol-E 유도체의 합성에서 필수적으로 요구되었던 두 개의 allylic hydroxyl groups는 먼저 tartrate ester의 partial reduction으로 dialdehyde를 형성하고, 여기에 vinyl Grignard reagent를 stereoselective bis-addition하여 도입하였다. 이 때의 stereochemistry는 Felkin-Anh model로 설명되어질 수 있다. Cyclohexenyl 고리의 형성은 conduritol-E 유도체의 합성에서 가장 중요한 과정으로 ring-closing olefin metathesis(RCM) 반응을 이용하여 수행하였다. 본 연구의 합성 방법은 매우 간단하며 출발물질에 따라 언하는 enantiomeric conduritol-E를 만들 수 있다는 장점이 있다. Part B에서는 16-membered lactone skeleton을 가진 antibiotic (-)-A26771B를 formal synthesis하였다. (-)-A26771B의 lactone moiety를 만들기 위하여 기존에 보고된 많은 합성 방법들과는 달리 intermolecular esterification을 통해 linear tri-olefin precursor를 만들었고, RCM을 이용하여 lactone 고리를 완성하였다. 이를 위해 furylcarbinol을 oxidative ring cleavage하여 intermolecular esterification을 위해 필요한 conjugated carboxylic acid를 만들었고, coupling을 위한 다른 한 부부인 alcohol은 이미 stereogenic center를 갖고 있는 epoxide를 ring opening하여 만들었다. 이 때, acid를 형성하기 위한 furylcarbinol과 coupling을 위한 alcohol을 준비하는 과정에서 공통적으로 4-pentenylmagnesium bromide를 사용하였는데 이러한 점은 본 연구의 비교적 간단하고 쉬운 방법으로 target molecule인 (-)-A26771B를 합성하고자 하는 synthetic approach의 큰 장점 중 하나이다.

고등학교 수학교육에 있어서 미분에 관한 평균값정리의 활용

이우화 대구가톨릭대학교 교육대학원 2003 국내석사

This study proposed its differences and complementary measures through comparing and analyzing textbooks and reference books of the sixth and seventh curricula of mathematics education for academic high school students, in order to use them for the mean value theorem in differential for the academic high school mathematics education curricula. Then, this study also attempted to find the solutions for improvement of students' logical thinking flexibility and more practices of the mean value theorem in differential, by suggesting the differences and complementary measures after comparing and analyzing the application of the mean value theorem in differential used for the mathematics education curriculum in university.

박경리 「토지」에 나타난 傳統的 價値觀에 관한 硏究

이우화 한국교원대학교 교육대학원 2003 국내석사

지적세부측량에 있어서 RTK-GPS의 활용 방안

이우화 청주대학교 사회복지행정대학원 2008 국내석사

To survey a land by using RTK-GPS in a wide field can be somewhat expected the accuracy and efficiency. Nevertheless, we can not adopt it in a cadastral surveying field because statutory guidelines have not prepared. In fact, we can not deny that it is unsuitable in a densely built-up area because the satellite reception is not clear. That is the main reason why we have not been able to use the method in surveying a land parcel. In this context, this study intended to examine problems occurred in adopting a RTK-GPS in a field and to propose plans that we can use it in a cadastral surveying field. If there is no difference between an existing result and new one which surveyed though other Reference Stations it is perfectly possible for a surveyor to save expense and time. Therefore, I tried to prove it after a control experiment. Firstly, I choose the 120 points in the specific area and surveyed with the method of RTK-GPS. Then I compared the new results with the existing one. After the analysis, I could recognized that it did not make a scrap of difference. As a result, we can examine an accuracy of the result without repeated survey when we select other Reference Stations. In conclusion, this study proposed that (ⅰ) the act for practical use of RTK-GPS in a cadastral field should be prepared, (ⅱ) the RTK-GPS has to be closely connected with the existing surveying method(i.g., Total Station), (ⅲ) the method of Network RTK needs to be introduced to improve accuracy of Reference Stations, (ⅳ) the GPS, GLONASS and Galileo satellite should be unified in order to guarantee a stability of surveying outcomes.

이광래 후기 희곡에 나타난 구원 문제 연구

이우화 계명대학교 교육대학원 1995 국내석사

Study on high performance thermoelectric generator using carbon nanotubes and conducting polymers

이우화 성균관대학교 일반대학원 2017 국내석사

The influence of processing conditions, such as ink concentration and coating method, on the thermoelectric properties of SWCNT/P3HT nanocomposite films was investigated systematically. Using simple wire-bar-coating, SWCNT/P3HT nanocomposite films with high thermoelectric performance could be obtained without additional P3HT doping. The wire-bar-coated SWCNT/P3HT nanocomposite films exhibited power factors of up to 105 µW m-1K-2 at room temperature. The SWCNT bundles with diameters in the range of 6 – 23 nm formed an interconnected network in the wire-bar-coated nanocomposite films. Network formation in these nanocomposite films was expected to be strongly related to the development of electrical pathways due to inter-SWCNT bundle connections. This study suggests that the thermoelectric performance of SWCNT/P3HT nanocomposite films could be optimized by controlling their processing conditions and morphology. Moreover, this study investigates a coating method for doping single-walled carbon nanotube (SWCNT)/poly(3-hexylthiophene) (P3HT) hybrid film. In the hybrid film, P3HT chains were very highly doped by simple spin-coating of a FeCl3/nitromethane solution. Hybrid films doped by spin-coating exhibited power factors of 267 ± 38 µW m-1K-2, which is an improvement over that of hybrid films doped by conventional immersion, 103 ± 24 µW m-1K-2. The excellent thermoelectric performance is originated from the dramatically increased electrical conductivity by the sufficient doping of P3HT in the hybrid films.

중국 고등교육기관의 평생교육정책 연구

우화 숭실대학교 대학원 2007 국내석사

무선전력전송 및 선형전동기 결합시스템의 무선전력전송 시스템 설계

우화진 창원대학교 2022 국내석사

This paper proposed the transformer characteristic analysis method for the wireless power transfer (WPT) device and linear motor (LM) integration system that can be applied to industrial cleanroom transfer systems. A cable is required to supply the power in conventional systems. In comparison, the proposed system utilizes a WPT device that can simplify power transfers and make a better space utilization. The shape of the wireless power transmission system is proposed along with the discussion of the 2D FEA analysis method about the inductance analyzing method, which are important parameters in magnetic coupling. In addition, ferrite iron loss was calculated based on the analysis results, and applied to the entire modeling circuit to verify the validity of the measured and analyzed values. Finally, the proposed analysis method for the transformer coupling characteristics of the wireless power transfer combined with the transfer system is verified by experiments and simulations. In addition, the WPTLM device was actually implemented, and the output and efficiency were verified close to the design value.

비정질 As₂S₃박막의 편광홀로그램 기록 특성

우화제 강원대학교 대학원 1993 국내석사

Photoinduced anisotropic constants(birefringence and dichroism) of the As_(2)S_(3) thin film have been measured by means of rotating analyzer ellipsometry(RAE). Time dependent characteristics of the photoinduced anisotropy have been investigated at λ = 632.8nm as a function of the recording beam(Ar ion laser, X=514.5 nm) Power density. The polarization hologram constructed by orthogonally polarized two beam was recorded on amorphous As_(2)S_(3) thin film and their diffraction characteristics have been investigated. Ar-ion laser beam(λ=514. 5 run) and He-Ne laser beam(λ= 632.8nm) were used to record and read the polarization hologram, respectively. From the hologram recorded by two orthogonally linearly polarized bean we obtained the maximum diffraction efficiency of 0.04% and observed that the diffraction efficiency are independent of polarization state of reading bean. When the polarization state of two recording beam are orthogonal circular, the diffraction efficiencies (maximum 0.6%) are given by a function of reading beam polarization. By using this result, two images are recorded at a point on the armorphous As_(2)S_(3) thin film by using two orthogonally circularly polarized beam and selectively reconstructed by using left or right circularly polarized reading bean. We generated the phase conjugate wave with various polarization configuration of pump and probe beam and polarization charateristic of signal wave have been investigated.

자아존중감 및 사회성 발달을 위한 미술교육 연구 : 중학교 미술수업을 중심으로

우화령 중앙대학교 교육대학원 2013 국내석사

인생의 중심을 잡아가는 시기인 청소년 시기는 앞으로 자신의 인생을 어떤 식으로 이끌고 나아갈지를 정해야 하는 아주 중요한 시기이다. 또한 불확실한 미래를 향해 삶을 만들어가는 시기 또한 청소년 시기이다. 미래를 결정지을 중요한 시기에 학교와 교사는 학생들에게 자신의 문제에 대한 해결방법을 함께 모색하고 참된 행복감을 찾을 수 있도록 하는데 도움을 주어야 한다. 더욱이 미술교사는 자아존중감과 사회성 향상을 위한 미술 활동 시간을 제공하여 학생들이 가지고 있는 감정을 승화시킬 수 있는 다양한 수업 방안을 모색해야 할 것이다. 오늘날 청소년들은 부모와 교사의 높은 기대 속에 입시에 대한 심적 부담감과 압박감으로 낮은 자아존중감과 사회성을 가지고 있다. 이러한 청소년의 문제를 미술 교과에서 어느 정도 해결하고자 2009개정 교육과정에서는 지각과 소통이라는 대단원을 새로 설정하여 학생들이 미술활동을 통해 결핍된 자존감과 사회성을 자신에 대한 만족감과 자아존중감, 성취감을 경험할 수 있는 방안을 내세운바 있다. 이에 본 연구에서는, 미술 수업 프로그램을 통해 학생들의 자아존중감과 사회성 향상에 의미 있는 영향을 미치는가를 확인하는데 있다. 연구의 대상은 중학교 1, 2학년 학생 128명을 대상으로, 수행평가와 이외의 미술활동에서 할 수 있는 프로그램을 한 학년 동안 진행하였다. 프로그램 종료 후 설문 조사와 학생 상담을 통해 다음과 같은 결론을 얻을 수 있었다. 첫째, 학생의 자아존중감 검사에서 여러 가지 기법으로 자화상 그리기, 나를 소개하는 북 아트 만들기, 나의 꿈을 사진으로 이루어보기의 주제로 미술수업을 실시한 연구집단과 일반적인 미술수업을 실시한 비교집단 간 유의미한 차이를 보였으며, 연구집단을 통한 미술수업이 보다 효과가 있는 것으로 나타났다. 학생들은 수업을 통해 적극적인 자기 탐구와 함께 진로를 포함한 미래 탐색의 폭을 넓혀 자신의 자아를 긍정적인 방향으로 설정해 나가는 태도를 보였다. 둘째, 학생의 사회성 검사에서 학급 스탬프 만들기, 우리학교 실내 환경 디자인하기, 친구와 함께 바디 페인팅하기의 주제로 미술 수업을 실시한 연구집단과 일반적인 미술수업을 실시한 비교집단 간 유의미한 차이를 보였으며, 연구집단을 통한 미술수업이 보다 효과가 있는 것으로 나타났다. 학생들은 자신을 둘러싸고 있는 환경, 즉 학급과 학교에 대해 생각하는 시간과 작품으로 표현하는 활동을 통해 친사회적인 경험을 할 수 있었으며, 친구들과 함께 작품을 제작하는 과정을 통해 협동성과 사교성을 향상시키게 되었다. 셋째, 자아존중감과 사회성 향상을 위한 미술수업 활동 과정에서 교사의 관찰과 학생의 소감문을 분석한 결과, 자신의 가치를 높이게 인식하게 되었으며, 다른 친구들과 활발히 상호작용 하는 수업을 통해 보다 높은 흥미를 보였고 즐거운 마음으로 활동에 참여하였다는 것을 알 수 있다. 따라서 본 논문의 의의는 미술 수업이 중학생의 자아존중감과 사회성 향상에 도움이 된다는 사실을 확인하였다는 것에 있다. The adolescent time when the center of life is established is very important time for determining the direction of the life in the future. In addition, adolescent time is when the life can be created for the uncertain future. In the important time to determine the future, the school and teachers should help the students to fined real happiness by promoting the solution of their problems together. Furthermore, the art teachers should provide the time for the art activity for the self-esteem and sociality improvement to promote the various lesson plans to sublimate the students’emotion. The current adolescents have the low self-esteem and sociality due to the mental pressure and tightness about the entrance examination in the high expectations of their parents and teachers. To solve the adolescents’ problems through the art curriculum, the perception and communication as new plan was set in 2009 revised curriculum, so the plan for the students’ experience about their contentment and self-esteem, sense of accomplishment about the absence of the self-regard and sociality through the art activity was suggested. Therefore, this study aims to examine the significant effects of the art lesson program on the students’self-esteem and sociality improvement. As the subject of this study, the performance assessment and the additional programs of the art activity were conducted for one semester based on 128 middle school first, second graders. After finishing the program, the following conclusions through the surveys and student counseling were obtained. First, it showed significant difference between the comparative groups such as the research group conducted the art lesson with subject of several techniques such as the self-portrait drawing, the book art creation for introducing themselves, dreams come true by photo and the groups with general art lesson in the self-esteem test, and art lesson through the research groups was more effective. The students showed the attitude to set their ego in the positive direction by expending the width of future navigation including the active self explores and career through the lesson. Second, it showed significant difference between the comparative groups such as the research group conducted the art lesson with subject of creating a stamp class, designing our school indoor environment, body painting with friends and the groups with general art lesson in the sociality test, and art lesson through the research groups was more effective. The students could have the social-friendly experience through the activity of expressing works and time to think about the classroom and school as the surrounded environment, and the spirit of team work and sociability could be improved through the process of making works with their friends. Third, in the result of the analysis on the students’ paper for the impression and teachers’ observation in the process of the art lesson activity for the self-esteem and sociality improvement, they could recognize their value high and they showed high interest through the lesson of actively interface with their friends and it can be seen that they could participate in the activity with a happy feeling. Therefore, the significance of this paper is confirming the fact that the art helps the improvement of the middle school students’self-esteem and sociality.