서울의 Penicillinase Producing Neisseria Gonorrhoeae 발생빈도(1996)

김재홍,황동규,전재홍,김윤석,김중환,김용준,이창균,임동진,김현수,조창근,김경문,박상훈,전우형,김희성,이호정,차명수,김갑형,김형석,김석우,황지환,박병순,권오상,이민수,송기훈,성소영,이인섭,부태성 대한화학요법학회 1999 대한화학요법학회지 Vol.17 No.2

Background : In recent years, gonorrhea has been panedemic and remains one of the most commom STDs in the world, especially in developing countries. Objective & Methods: For the detection of a more effective therapeutic regimen and assessing the prevalence of PPNG, we have been trying to study the patients who have visited the VD Clinic of Choong-Ku Public Health Center in Seoul since 1980 by means of the chromogenic cephalosporin method. Results: In 1996, 139 strains of N. gonorrhoeae were isolated, among which 53(39.0%) were PPNG. Conclusion: Our results suggests that after a peak of 74.3% in 1993, the prevalence of PPNG in Seoul is gradually declining.

서울의 Penicillinase Producing Neisseria Gonorrhoeae 발생빈도(1994)

김재홍,안진균,정성재,김영태,김중환,김시영,이석종,이홍렬,서호석,김경훈,권혁진,정우권,고우석,이용석,안필수,오준규,오용섭 대한화학요법학회 1996 대한화학요법학회지 Vol.14 No.1

Background : In recent years gonorrhoea has been panendemic and remains one of the most common Sexually Transmitted Diseases in the world, especially in developing countries. Objective & Method : For the detection of a more effective therapeutic regimen and assessing the prevalence of Penicillinase Producing Neisseria Gonorrhoeae(PPNG), Ive have been trying to study the patients who have visited the VD Clinic of Choong-Ku Public Health Center in Seoul since 1980 by means of the chromogenic cephalosporin method. Results : In 1994, 168 strains of N. gonorrhoeae were isolated, among which 109 (64,9% ) were PPNG. Conclustion : Our results suggests that the prevalence of PPNG in Seoul is still increasing.

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.

Transitional Butterworth-Chebyshev 近似式을 구하는 프로그램 開發에 關한 연구

金煥宇 충남대학교 공업교육연구소 1982 論文集 Vol.5 No.1

In this thesis, a computer program is developed to find the Transitional Butterworth-Chebyshev approximations. By using it, we can find any transitional approximation, including Butterworth and Chebyshev approximations, whose dimension ranges from 1 to 10 and which has the cut-off frequency of 1 rad/sec, ripple facter ε, and transition constant k which ranges from 0 to the dimension of the approximation, and we can get its magnitude and phase characteristics. As an example, five 8-th order approximations whose transition constants k's are 0, 2, 4, 6, and 8 respectively are presented, and their magnitude and phase characteristics are calculated.

316(LN)스테인리스강의 열피로 특성에 미치는 질소의 영향

김대환,한창희,류우석 대한금속재료학회 2005 대한금속·재료학회지 Vol.43 No.5

Three different fatigue tests for 316 and 316LN stainless steels were conducted at RT, 600℃ and Ast= 1% for low cycle fatigue, at 200~400℃, 300~600℃ and Δε_(t) = 0% for thermal fatigue, and at 300~600℃ and Δε_(t) = 2% for thermomechanical fatigue. Low cycle, thermal and thermomechanical fatigue lives increased with the addition of nitrogen. Low cycle, thermal fatigue strength was increased but thermomechanical fatigue strength was almost same with the addition of nitrogen. Thermal fatigue life was decreased but thermal fatigue strength was increased at the higher temperature range. Thermomechanical fatigue life of in-phase was longer than that of out-of-phase. Fracture mode was transgranular for all tests. (Received September 3, 2004)

316LN 스테인리스 강에서 질소에 의한 결정립 미세화가 고온 기계적 특성에 미치는 영향

김대환,이요섭,류우석 대한금속재료학회 2004 대한금속·재료학회지 Vol.42 No.7

Mechanical tests, such as tensile, fatigue and creep, of type 316L(N) stainless steel containing 0.04 and 0.10 wt% nitrogen content were conducted at 600℃ to investigate the grain size effect on the behaviors of mechanical properties since grain size was refined with the addition of nitrogen. Yield strength and fatigue life increased with the addition of nitrogen and the decrease of grain size. The creep rupture time was increased with the addition of nitrogen but decreased with increasing grain size. The change in minimum creep rate with grain size was consistent with the result predicted from Garofalo's equation. (Received November 17, 2004)

비접촉식 측정데이터를 이용한 근사 곡면 생성 및 영역화

김재현,박정환,고태조,유우식 嶺南大學校 工業技術硏究所 2001 工業技術硏究所論文集 Vol.29 No.2

As well known, the non-contact measuring method via the laser scanning or vision system provides vast amount of measuring points by which we rapidly identify the overall shape. On the other hand, its measuring accuracy (resolution) may be lower than that of touch probing method. From the reverse engineer's point of view, it is meaningful and efficient to fully utilize the merits of each methodology. This paper describes the construction of an overall approximate surface model by the non-contact measurement data (cloud-of-points), and the segmentation scheme for identifying sub-areas which should further be digitized by a scanning touch probe. The segmentation is performed through extracting the featured boundary edges or shapes (sharp edges or blend surfaces) by a pencil curve tracing algorithm.

Retinoic acid에 의해 유발된 흰쥐의 구개열에서 Transforming Growth Factor-beta 1, 2, 3의 발현의 변화

김종환,박진혁,신선호,윤혜경,김우형,이희철 인제대학교 백병원 2002 仁濟醫學 Vol.23 No.4

Objective : Craniofacial malformations are among the most frequent congenital birth defects in humans : cleft palate, that is inadequate fusion of the palatal shelves. Retinoic acid is teratogenic in many species, producing multiple malformations, including cleft palate. Also it plays an important role in embryogenesis, by regulating morphogenesis, cell proliferation, differentiation, and deposition of the extracellular matrix. The effects of retinoic acid which leads to cleft palate vary depending on the stage of development exposed. After exposure of embryonic mice to retinoic acid on gestational day(GD) 10, abnormally small palatal shelves form. And the elevation of palatal shelves is delayed. The growth and differentiation factor, transforming growth factor-beta(TGFβ) family is thought to play important roles in multiple developmental processes, especially, the development of the embryonic palate. The expression of the TGFβ family in embryonic palate suggests a functional role for these molecules. In this study, author has determined the tissue distributions of TGFβ family in murine embryonic palate, and compared them in terms of developmental stage and locations in normal and retinoic acid-induced cleft palate. Methods and Material : Retinoic acid was administered orally at gestational day(GD) 10 to ICR mice. The pregnant mice were sacrifeced on GD 12, 13. 14, 15 to obtain the fetuses and immunohistochemistry was performed. And using the scanning electron microscope, morphology of normal palate and cleft palate was studied. Results : In the retinoic acid-treated fetuses, palatal shelves did not elevate and cleft palate was induced. On GD 13 in the palates of the retinoic acid-treated fetuses, expression of the TGFβ1, 3 decreased dramatically, but that of TGFβ2, did not change. The expression of the TGFβ1, 3 in the palates of the retinoic acid-treated fetuses, increased on GD 14, 15, Significant differences in TGFβ family expression were observed with areas of the palate. Conclusion : These results suggest that retinoic acid inhibits the expression of TGFβ 1, 3, which is critical in the developing palate, and elevation of palatal shelves is delayed and impaired, therefore cleft palate is induced. These data demonstrate a role for retinoic acid and retinoic aicd-induced TGFβ family in the regulation of palatal development and suggest a role for TGFβ in retinoic acid-induced cleft palate.

Type 316L(N) 스테인리스 강의 최적질소함량 평가

金大煥,金雨坤,柳禹錫 대한금속재료학회 2002 대한금속·재료학회지 Vol.40 No.6

Tensile, fatigue, creep-fatigue, creep tests were conducted at R.T.∼600℃ to evaluate the effect of nitrogen on mechanical properties and the optimum nitrogen content for type 316L(N) stainless steel containing the different nitrogen content from 0.04% to 0.15%. Tensile strength decreased with temperature and increased with the addition of nitrogen but elongation was not decreased with the addition of nitrogen. Fatigue life was almost same up to 300℃ and decreased drastically at 600℃. Fatigue life increased with the addition of nitrogen but decreased at above 0.10% nitrogen content. Fatigue crack propagation increased with temperature, decreased with the addition of nitrogen, and increased at above 0.10% nitrogen content. The time to rupture for creep increased with the addition of nitrogen and saturated at above 0.10% nitrogen content. Minimum creep rate of creep decreased with the addition of nitrogen. Creep-fatigue life increased with the addition of nitrogen but decreased at above 0.10% nitrogen content. Mechanical properties were improved up to 0.10% nitrogen content but saturated or decreased at above 0.10% nitrogen content. The optimum nitrogen content for the high temperature mechanical properties of type 316L(N) stainless steel was evaluated as 0.10% in the 0.02% carbon content.

능동 저역 여파기 설계를 위한 프로그램 개발에 관한 연구

金煥宇 충남대학교 공업교육연구소 1982 論文集 Vol.5 No.2

A computer program was developed to find the values of circuit components in an active lowpass filter network. A fourth-order low-pass filter is realized by the use of the program, from which |G(if)| is obtained and compared with the theoretical values.