낭성 수막종 -1증례 보고-

박재훈,유소연,김윤화,박용구,양문호 대한병리학회 1991 Journal of Pathology and Translational Medicine Vol.25 No.2

양방향 요소제거법을 이용한 신뢰성 기반 최적설계

유진식,박재용,황승민,임민규,오영규,한석영 한국공작기계학회 2008 한국공작기계학회 추계학술대회논문집 Vol.2008 No.-

This research presents a Reliability-Based Topology Optimization (RBTO) using Bi-directional Evolutionary Structural Optimization (BESO). An actual design involves uncertain conditions such as material property, operational load and dimensional variation. Deterministic Topology Optimization (DTO) is obtained without considering of uncertainties related to the uncertainty parameters. However, RBTO involves evaluation of probabilistic constraints, which can be done in two different ways, the reliability index approach (RIA) and the performance measure approach (PMA). The reliability index approach (RIA) and the performance measure approach (PMA) are adopted to evaluate the probabilistic constraints. In order to apply the BESO method to the RBTO, sensitivity number is defined as the change in the reliability index due to the addition or the removal of the ith element. In the BESO, a mesh-independency filter using nodal variables is used to remove the checkerboard patterns. The optimal topologies of RIA and PMA are obtained very similarly. It is shown that RBTO based on BESO can be effectively applied from the presented examples.

등방성-등방성 이종재료에 대한 균열 선단에서의 코스틱스 상에 관한 해석

유재용,문윤배 대구미래대학 2001 論文集 Vol.19 No.1

For the stress analysis in bi-materials, there have been used many theoretical and experimental methods. The experimental methods such as Morie, Photoelasticity, holography and caustics are primarily used by many researchers. In this paper, as the first step to develop the experimental method of caustics in bi-materials, the initial and caustic curve equations are established by introducing the existing stress component equations to the equation of the formation of Caustics and made the program for the generation of caustics in computer.

Pt계 촉매를 이용한 직접 개미산 연료전지의 특성 연구

유재근,이효송,김진용,김기호,이영우 충남대학교 공업교육연구소 2005 論文集 Vol.27 No.1

Direct Formic Acid Fuel Cells (DFAFCs) are potential alternative power sources for potable devices such as cellular phones, personal digital assistants (PDA) and laptop computers. In this study, we investigated the effect of the anode catalysts on the performance of direct formic acid fuel cell. We made the Pt-Pd catalysts using deposition method for the investigation of the fuel cell performance as a change of temperature and oxidant. Fuel cell with Pt-Pd anode catalyst showed the performance of 120 mW/㎠at room temperature. This result was much higher value than that of Pt-Ru catalyst which showed the best performance of commercial catalyst in our previous works. For this reason, we can conclude that the Pt-Pd catalyst is an excellent material for the oxidation of formic acid.

플라즈마 질화법에 의한 SKD 11 공구강의 표면 경화에 관한 연구

유용주,이재식,공경준 울산대학교 1996 공학연구논문집 Vol.27 No.2

본 연구는 온도범위 450 - 650℃, NH₃ 가스유량 0.5 - 2.1 l/min., 처리시간 20 - 110분의 조건에서 SKD 11 냉간 금형용 공구강을 플라즈마 질화처리하여 강 표면에 생성된 경화층(화합물층 및 확산층)의 조성 및 두께와 각각의 경도값을 조사하여 질화의 최적조건을 찾고자 하였다. 반응온도 550℃, NH₃2.1 l/min., 반응시간 110분일 경우 14㎛의 최대 화합물층을 얻었으며, 반응온도 550℃, NH₃1.65 l/min.로 110분간 반응시켰을 때 생성된 확산층은 210㎛였으며, 최대 질화층은 220㎛이었다. 또한, 플라즈마 질화처리한 SKD 11 냉간 금형용 공구강 표면과 화합물층을 XRD로 분석한 결과 450℃와 500℃에서는 r' - Fe₄N + α - Fe로, 550℃에서는 r' - Fe₄N - ε -Fe₂₃N, 그리고 600℃ 이상에서는 r' - Fe₄N + α + Fe로 구성되어 있는 혼합상이었다. 550℃, NH₃1.65l/min., 80분간 질화처리 하였을 때 생성된 질화층의 최대표면경도는 Hv 1100이었다. The plasma nitriding of SKD 11 tool steel has been studied at the temperature between 450℃ and 650℃ with gas flow rate of NH₃ 0.5 to 2.1 l/min. for 20 to 110 minutes. The phases of compound layer formed below 500℃ and above 600℃ was mixtures of r'-Fe₄N and α- Fe phases, while the phases formed at 550℃ was r'-Fe₄N and ε-Fe₂₄N phases. The thichness of compound layer formed at 550℃ with gas flow of NH₃2.1 l/min. for 110 minutes was 14㎛. The thickness fo nitrided layer formed at 550℃ with gas flow rate of NH₃1.65 l/min. for 110 minutes was 220㎛. The nitrided layer was composed of 10㎛ compound layer and 210㎛ diffusion layer. The hardness of nitrided layer formed at 550℃ with gas flow rate of NH₃ 1.65 l/min. for 80minutes was Hv 1100.

구강저에 발생한 단독형 신경섬유종

김용각,유현석,곽재근,김규영,정붕희 大韓顎顔面成形再建外科學會 1990 Maxillofacial Plastic Reconstructive Surgery Vol.12 No.3

Benign neural sheath neoplasms are not common in the maxillofacial region. These lesions can occur as solitary tumors, or they can affect many sites in the form of multiple neurofibromatosis. A solitary neurofibroma is seldom undergo sarcomatous transformation, since solitary neurofibroma is relatively radioresistant and its recurrence rate seems to be low, the treatment of choice is surgical excision. This case showed a solitary neurofibroma in the left side of the floor of mouth which occurred in a 33 - year -old female. The tumor was excised. And there is no evidence of disease. She is satisfied in function and esthetic aspect.

初等學校 『쓰기』敎科書 分析 硏究 : 高學年을 中心으로

김용재,유지연 全州敎育大學校 初等敎育硏究所 1995 初等敎育硏究 Vol.6 No.-

이 논문은 쓰기 교과서를 글쓰기 상황과 글쓰기 과정 진술을 분석해 보았다. 글쓰기 상황은 주제, 목적, 예상 독자로 나누어 분석하였고, 글쓰기 과정은 아이디어 발견 단계, 아이디어 조정 단계, 텍스트 생산 단계, 고쳐쓰기 단계로 나누어 분석하였다. 그 분석 결과를 종합해 보면 고학년 『쓰기』 교과서는 글쓰기의 상황이나 글쓰기 과정을 아동의 경험, 수준에 맞게 제시하고 있다. 그러나, 글쓰기 상황의 주제, 목적, 독자 요소에 대한 진술은 지나치게 일반적인 상황이라서 흥미 유발에는 적합하지 못하다. 따라서. 학습 현장에서 활용할 때는 교과서의 상황 설정을 기준으로 지역적인 특성이나 학교의 상황, 아동의 특별한 경험 등을 고려한 흥미진진하고 생동감있는 구체 상황으로 진술하여 재구성할 필요가 있다. 또, 글쓰기 과정은 아이디어 발견, 아이디어 생산 텍스트 생산, 고쳐쓰기의 순서가 나타나는 정도에 그치고 있으므로 다양한 사고를 유도하는 효과를 거두기가 어렵다. 따라서, 각 단계마다 적절한 방법을 활용하여 복합적인 사고 활동을 유도하도록 재구성해야 한다.

관상동맥 누공에 의한 급성 심근 경색 1예

서유승,최재웅,송창섭,조용범,양진수,박준섭,정인수 대한내과학회 2003 대한내과학회지 Vol.65 No.2

관상동맥 동정맥루 기형은 매우 드문 질환으로 치료가 불필요한 경우가 대부분이나 coronary steal 현상으로 인해 증상이 발생하거나 합병증이 발생한 환자에 대해선 치료를 요한다. 최근에는 시술에 적합한 누공을 가진 선택된 환자군을 대상으로 카테터를 이용한 중재적 시술이 시행되어 수술적 치료와 유사한 결과를 얻고 있다. 저자들은 젊은 남자에서 관상동맥 동정맥루 기형과 동반된 급성 심근 경색증을 진단하여 비 수술적 방법인 카테타 코일 색전술로 성공적 치료 후 증상 및 심근 재관류에 호전을 보인 증례를 경험하였기에 문헌고찰과 함께 보고하는 바이다. We report a case of coronary fistula between the left anterior descending and main pulmonary artery complicating acute non-Q wave myocardial infarction. A 27-year-old man visited emergency department because of severe chest pain lasting two hours. The electrocardiogram showed ST segment elevation in precordial leads V3~6. Cardiac enzymes were as follows;CK-MB:36.44 IU/L T-T:0.489 ng/mL, CPK:542 IU/L, and LDH:475 IU/L. The thallium-201 dipyridamole stress perfusion scan showed perfusion defect and reversed redistribution in the anteroseptal wall. The coronary angiogram revealed coronary artery fistula between the proximal left anterior descending artery and main pulmonary artery without significant stenoses of coronary arteries. The result of ergonovine test was negative. After micro-coil embolization to the coronary fistula, symptoms were improved. Follow-up thallium-201 scan showed normalized blood flow in the left anteroseptal wall.

개에서 발생한 폐수종의 치료 증례

김유수,심재현,김건우,김지용,이병희,송근호,이영원,김덕환 충남대학교 수의과대학 동물의과학연구소 2004 動物醫科學硏究誌 Vol.12 No.-

A 9 months intact male American bull dog with chief complaints of dry cough, dyspnea and fever was referred to the Veterinary Teaching Hospital, Chungnam National University. Based on the findings of physical examination, radiological examination, and blood and blood chemical examinations, the present patient was diagnosed into pulmonary edema secondary to primary bacterial and aspiration pneumonia. The patient was hospitalized and treated with buscopan, cephazolin and furosemide for 1 week. His activity and appetite was returned to normal and thoracic radiographs revealed that Jung was recovered to the normal condition after treatment for 7 days. The present patient was a case with pulmonary edema showed favorable therapeutic responses to proper medication.

동적 모드Ⅲ 하중을 받는 등방성체/직교이방성체 이종재료의 파이버 각도변화가 응력 및 위 성분에 미치는 영향

하재기,유재용 김천과학대학 2001 김천과학대학 논문집 Vol.27 No.-

In interpreting problems of bimaterial fracture mechanics, it is important to understand stress and displacement on the interface of bimaterial. Especially, a crack contained in the interface of the bimaterial has more complicated and dangerous fracture behavior than a crack contained in general material does. Therefore, the fracture problems of an interface crack in the bimaterial has been attracted by many researchers. In this paper, a crack on bond interface gets the load of dynamic modeⅢ and proceeds to the steady state when the mediums, i.e., isotropic/orthotropic material, are combined. In other words, we induce stress field and displacement field near a crack tip, and general stress field and displacement field apart from a crack tip in case that the velocity of a crack and direction are proportion to the change of time. And we then investigate the effect of the fiber direction of isotropic/orthotropic material to the stress and displacement fields of modeⅢ occured in the bi-material interfacial under constant velocity crack.