신규 3작용성 메타크릴레이트의 치과용 광중합형 콤포짓트 레진용 단량체로서의 응용 연구

김중곤,정찬문,김민성,김광만,김경남 大韓齒科器材學會 2001 대한치과재료학회지 Vol.28 No.4

Tris[4-(2-hydroxy-3-methacryloxypropoxy)phenyl]methane(THMPM) was prepared easily from triphenylolmethane triglycidyl ether in good yield. As compared with composite resin formulated with difunctional bis-GMA, the physical properties of a newly developed composite resin formulated with trifunctional THMPM was evaluated. Cytotoxicity and acute toxicity of composite resin based on trifunctional THMPM evaluated according to ISO standard method. The depth of cure of the composite resin based THMPM was higher than that of the bis-GMA composite. There were no significant differences in flexural strength and water sorption between the composites resin based on THMPM and bis-GMA. The water-solubility value for the light-activated composite resins formulated with THMPM was much lower than that for a control bis-GMA composite. According to cytotoxicity evaluation, the composite resin based on THMPM showed very mild cytotoxicity with the response index of between 0/0 and 1/0. No acute toxicity of composite resin formulated with trifunctional THMPM was also observed. It is believed that THMPM is promising candidate for application as a photocurable dental composite resin.

HID 램프용 디지털제어 전자식 안정기에 관한 연구

김영동,강원찬,김남오,김형곤,김병철 조선대학교 에너지.자원신기술연구소 2004 에너지·자원신기술연구소 논문지 Vol.26 No.1

In this paper, digitally controlled electronic ballast for the HID lamps driven by proposed frequency conversion method is described. This electronic ballast consists of a buck converter, a low frequency square wave full bridge inverter, a high voltage pulse generator for the lamp ignition, an over current protection circuit and an 8-bit microcontroller. The fuzzy logic digital control operation is carried out by the 8-bit microcontroller. In spite of the limited control bandwidth caused by low operation speed of the 8-bit microcontroller, the good control performance for the constant lamp current in the warm-up period is obtained using the proposed frequency conversion driving method. The HID lamp is controlled in a constant current mode during the lighting warm up process and is controlled in a constant power mode during lighting steady state. A controlled variable power mode is used to extend the lamp lifetime.

실리카흄을 흔입한 고강도 콘크리트 개발

홍창우,김태경,김경진,김성환,김남윤,심도식,이정호,윤청호,백민경,원치문,박제선,이주형,정경일 강원대학교 석재복합신소재제품연구센터 1996 석재연 논문집 Vol.1 No.-

콘크리트 구조물이 대형화됨에 따라 설계단면이 증대되어 상대적으로 많은 경제적 손실을 부담하게 된다. 따라서 단면을 감소시키면서도 소요의 하중에 안전한 구조물을 건설하기 위해서는 우선적으로 구조물 건설에 기초가 되는 고품질, 고내구성의 고강도 콘크리트 개발이 절실히 요구된다 본 연구에서는 일정 시멘트비 및 혼화재 비율하에서 소요의 워커빌리티가 확보되는 고강도 콘크리트를 시간과 온도의 변화에 따라 증기 양생하여, 압축, 인장, 휨강도 뿐만 아니라 파괴특성을 실험적으로 연구하였다. 시료 제작시 시멘트 입자 사이의 공극 및 불연속 영역을 충전하여 고밀도화하기 위한 콘크리트용 혼화재로 시멘트 비표면적이 상당히 작은 초미립 분말인 실리카흄을 이용하였다. 또한 AE감수제 및 고성능 유동화제를 사용하여 혼화재의 첨가에 의하여 발생될 수 있는 워커빌리티의 감소를 방지하였다. 실험결과에 의하면 일정 양생 지속 시간하에서 온도의 증가에 따라 콘크리트의 압축, 인장 및 휨강도가 전반적으로 증가하였다. 동일하게 일정 온도하에서 양생 지속시간이 커짐에 따라 강도들이 증가됨을 알 수 있었다. 따라서 상대적으로 높은 온도와 긴 지속 양생 조건하에서 파괴에 대한 저항력이 크게 나타났다. The compressible, tensible, and flexibleresistance of the high strength concrete is analyzed by the experimentation in the present study. For the test, we cure several samples with the silica fume as a mixture being become dense the spaces between the particle of cement under the variation of both the temperature and the curing-interval. Then, the superplasticizer and the ezcon are also used to satisfy the required workability for construction. The compressible, tensible, and flexible resistances to a stress are increased as increasing the temperature and the time interval for the curing. Therefore it is concluded that the overal fractural and mechanical properties is improved by mixing the silica fume into the cement.

소아의 상완골 원위부 과간 골절

이우석,정환용,김우식,김용찬,전택수,김남현,김규태 대한골절학회 2004 대한골절학회지 Vol.17 No.4

상완골 원위부 과간 골절은 소아에서는 매우 드물게 발생되는 골절로 대부분 주관절의 굴곡상태로 주관절 후방부에 직접적인 충격에 의해 발생하는 것으로 보고되고 있다. 전위가 없거나 경미한 경우 도수적 정복술 혹은 도수적 정복술 후 경피적 핀고정술을 시행하며, 전위가 심한 골절이거나 도수적 정복술이 불가능한 경우 관혈적 정복술 후 핀고정술을 시행하는 것으로 알려져 있다. 저자들은 전위된 상완골 원위부 과간 골절 환아 2예에서 각각 도수적 정복술과 관혈적 정복술 후 K 강선 고정술을 시행하여 만족한 결과를 얻었기에 보고하는 바이다. Intercondylar fractures of the distal humerus are very rare in children. The pattern of the fracture would suggest that the mechanism of injury involves a fall directly on the flexed elbow. Most agree that the undisplaced fracture can be managed conservatively. With increasing displacement and comminution, the opinions tend to differ. We suggest that closed reduction with percutaneous K wire pinning and open reduction with percutaneous K wire pinning offer a satisfactory methods by which to treat displaced intercondylar fracture in children.

후복막강내 발생한 Castleman병 1례

남성진,이동욱,박찬규,정시욱,김추성,조성래,구본천,양사규,이일웅,박정자 慶北大學校 醫科大學 1997 慶北醫大誌 Vol.38 No.2

Castleman' s disease is a rare, reactive lymphoid proliferation of unknown cause and pathogenesis. Depending on histololgic findings, it has been divided into two distinct histologic subtypes that include hyaline-vascular type(90%) and plasmacell type(10%). This disease occurs most commonly in mediastinal lymph nodes and cervical lymph nodes, inguinal lymph nodes respectively. But occurs rarely in retroperitoneum. We report a case of hyaline-vascular type asymptomatic Castleman' s disease of the retroperitoneum in a 47-year-old man.

위장관 출혈을 일으킨 공장의 형활근종 1예

김병수,장성종,부귀범,조운택,박찬국,김만우,변주남,김정용,전호종 조선대학교 2001 The Medical Journal of Chosun University Vol.26 No.1

Small bowel leiomyoma is a rare tumor which may occur wherever smooth muscle is present. The small bowel is the most common site and it makes up 20~30% of all benign small intestinal neoplasms. A spectrum of symptoms are common ranging from nausea, vomiting, abdominal pain, to massive intestinal bleeding. Bleeding is the most common symptom and is usually gross and recurrent. Occasionally it may be life threatening. But, the most serious problem is both the absence of specific clinical symptoms, and the difficulties shown in radiological diagnostics of the small bowel. If conventional diagnostic methods fail to reveal any positive findings for gastrointestinal bleeding, the diagnosis of intestinal leiomyoma should be suspected and an SMA angiography shoud be performed. The angiographic criteria of small bowel leiomyoma is very characteristic. We present a case of leiomyoma with considerable and prolonged gastrointestinal bleeding, which was diagnosed by angiography. A 61-year old woman was admitted with a history of melena over the last 10 days. An SMA angiography showed a hypervascular mass with a diameter of 3×3cm. A segmental resection was performed under the impression of the gastrointestinal bleeding due to leiomyoma of the small bowel. Microscopic examination of the lesion shows interlacing or whorl bundles of spindle shaped ces and no mitosis.

비모형화특성이 존재하는 연속시간 적응제어 알고리즘의 강인성 향상에 관한연구

김남준,이형찬 대진대학교 1994 大眞論叢 Vol.2 No.-

In this paper, a new robust diret adaptive controller using a modified adaptive law is suggested, in the presence of unmodeled dynamics and bounded disturbance in a linear time-invariant continuous system. The proposed algorithm consists of a conventional control law and the revised adaptive law to compensate for the drawback of o-modification algorithm. The proposed algorithm is applied to a plant with unmodeled dynamics represented as a singular perturbation. Boundness of all signals in overall system is guaranteed with mathematical analysis. Computer simulations show robustness of the proposed algorithm even in the presence of unmodelled dynamics or bounded disturbance simulatneously

경희대학교 수원캠퍼스 노천극장 기본계획

김동찬,이윤수,장동주,강남욱,민창기,김용옥 경희대학교 디자인연구원 2003 예술· 디자인학연구 Vol.6 No.1

The aim of this study is to design an open-air theatre to satisfy the demand of students about a place for events in Kyunghee University, Suwon campus. Furthermore, rapid growth of Suwon campus has been requested a suitable place for outdoor amphitheatre. The entire design of Kyunghee University campuses pursuit renaissance style, hence Greek and Roman styles were considered in this study. To make the open-air theater as a useful and distinctive place, the following design elements have to be considered: aesthetic, functional, subjective, symbolic and practical use of the theatre.

감귤하우스 토양과 노지토양의 화학적 성질과 미생물상

김찬식,강순선,오명협,현해남 濟州大學校亞熱帶農業硏究所 1996 亞熱帶農業硏究 Vol.13 No.-

SummaryDistributions of actinomycetes, bacteria, and fungi were examined in citrus house and field soils sampled from volcanic ash soil area. pH, electrical conductivity, and exchangeable K, Ca, and Mg content in citrus house soil were higher than them in citrus field soil, however, total nitrogen content in citrus house soil is lower than that in citrus field soil.Number of total microorganisms in citrus house soil was about 3.1×105, which was 10 times lower than that in citrus field soil, and also that was remarkably lower than similar group of volcanic ash soil in cultivating and upland soil. Number of actinomycetes and bacteria in citrus house soil were similar to citrus field soil, however, that of fungi in citrus house soil was lower than that in citrus field soil.Electical conductivity and Bray No. 1 P in citrus field soil and pH and exchangeable Mg content in citrus house soil were positively correlated with distribution of actinomycetes in soils and Bray No. 1 P in citrus field soil and exchangeable Mg content in citrus house soil were negatively correlated with distribution of fungi in soils Keywords : volcanic ash citrus orchard soil, soil chemical property, actinomycetes, bacteria, fungi in soils

웹 기반의 VRML 저작도구 설계 및 구현

김남규,박홍진,김영찬,고영삼 중앙대학교 정보통신연구소 2000 정보통신연구소논문집 Vol.2 No.2

웹 기술과 컴퓨터 하드웨어 기술이 빠르게 발전함에 따라 편리하고 현실적인 인터페이 스는 전송시간과 실행시간 보다 중요�. VRML은 웹에서 가상 현실을 구현하는 적합한 언어지만 일반 사용자에게 사용하기에 너무 어렵다. 또한, VRML이 변경될 때 마다 다시 구성해야하는 복잡성이 있다. 이러한 문제를 해결하기 위해 본 논문을 웹 기반의 VRML 저작도구를 구현한다. 또한 기존의 VRML과 데이터베이스 시스템을 분석하여 확장된 VRML 지원 시스템을 구현하여 이를 평가한다. As the web technology and the computer hardware have been rapidoy evolving, the convenient interface and reality is more important than the transmission time and the execution time. For satisfying these requirements, VRML is the most suitable language to implement virtual reality on the Web. However, it is too difficult for non-expert to use VRML. It is also complicated to reconstruct VRML whenever it changes. In order to resolve these problems, this paper implements VRML Authoring Tool based on web. Also, this paper analyze the problem of the existing the cooperating VRML and Database system, implement the extended VRML supporting system. and evaluate it with the existing system.