전자공학교육과 실험교과내용에 관한 연구

홍봉식,김태균,오승엽,김환우,권오석 충남대학교 공업교육연구소 1983 論文集 Vol.6 No.2(A)

The currenty offered experiment courses are completely reconsidered and reconfigured. The whole subjects are divided into 10 seperate courses, each of which should represent either basic or advanced stages of differing fields of the electronic engineering. It has been aimed that the courses form an elaborate hierachy so that they are minimally redundant but linked to one another in their fringes. Also, it has been pursued that the new courses should not fall obsolete in at last next five years exploring the maximum possibilities of the currently available equipments.

FEM을 이용한 선삭가공 절삭조건의 영향 분석

임세환,송춘삼,홍석관,강정진,김주현 한국공작기계학회 2007 한국공작기계학회 추계학술대회논문집 Vol.2007 No.-

A plane strain finite element model is developed to simulate turning with continuous chip formation using adaptive remeshing during the thermal-mechanical coupled analysis. Comparisons between the experimental and simulation results for cutting forces are performed to validate FE analysis results. Influences of machining parameters such as depth of cut, cutting speed and feed rate on cuting force and shear angle are analyzed by Taguchi method. The more depth of cut and feed rate result in the increase of cutting forces, but the rates of increase are decrease due to the larger shear angle. As the cutting speed increases, von Mises stress of workpiece near the tool tip decreases because the strength of specimen decreases at high temperature above 500℃. This thermal effect on cutting force is negligible because the affected area is very localized and the average values of von Mises stress in the shear plane are the same among the diverse cutting parameters.

서울의 Penicillinase Producing Neisseria gonorrhoeae 발생빈도(1997)

김재홍,문득곤,김정수,김용준,임동진,박상훈,김희성,이민수,송기훈,김갑형,김형석,성소영,이인섭,김석우,황지환,조창근,김경문,부태성 대한화학요법학회 2000 대한화학요법학회지 Vol.18 No.3

Background : In recent years, gonorrhea has been pandemic and remains one of the most common 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 Venereal Disease Clinic of Choong-Ku Public Health Center in Seoul since 1980 by means of the chromogenic cephalosporin method. Results : In 1997. 99 strains of N. gonorrhoeae were isolated, among which 45(45.5%) were PPNG. Conclusion : The prevalence of PPNG in Seoul, which had been decreased to 39% in 1996 after a peak of 74.3% in 1993, is increased to 45.5% in 1997.

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.

소방구급대원의 응급처치 적절성 평가와 재교육 필요성

류석용,김원율,김경환,이상래,이경호,김홍용,이승한 대한응급의학회 2000 대한응급의학회지 Vol.11 No.2

Background: The prehospital emergency medical system(EMS) for 119 rescue has progressed considerably, but leaves much to be desired. To improve prehospital EMS, we need to evaluate prehospital patient care, and reeducation. Methods: The records of 1,882 patients, who visited Sanggye Paik Hospital Emergency Department via 119 rescue from April 1 to July 30, 1999, were analyzed according to the quality of patient care as documented by the 119 rescue protocol and database. Patients are grouped into 5 classes based on the quality of the care received. Class 1A received adequate care, class 1B received inadequate care, class 1C did not receive the necessary care, and class 2A received unnecessary care, class 2B did not receive unnecessary care. The results of such analyses are presented to the fireman at monthly meetings, thus reeducating them. Results: The overall results were 1027 cases in Class 1A(55%), 83 in 1B(4%), 149 in 1C(8%), 21 in 2A(1%), and 602 in 2B(32%). Well performed care(1A+2B) occured in 1629 cases(87%) and badly performed care(1B+1C+2A) occured in 253cases(13%). Well perfomed care gradually increased from April to July (April 83%, May 85%, June 87%, and July 89%). Conclusion: Meticulous appraisal of the quality of prehospital patient care and reeducation through the regular meetings of EMS physicians and firemen in each community is needed for developing a model protocol for indirect retrospective medical control of the prehospital EMS.

휴대폰 케이스 가공업체에서 발생한 은피증 1예

탁기홍,윤석환,이미영,신동훈,정인성 대한산업의학회 2006 대한직업환경의학회지 Vol.18 No.4

배경: 은피증은 은의 피부 침착에 의해서 생기는 질환으로, 만성적인 노출에 의해 생기며, 치료법이 없는 영구적인 질병이다. 은의 흡입에 의한 은피증의 보고는 아주 드물며, 우리나라에는 현재까지 관련 보고가 없었다. 이에 휴대폰 도장제의 은 흡입에 의한 은피증을 보고하고자 한다. 증례: 30세 남자근로자로 5년 전부터 휴대폰 부품조립 및 도장업체에서 EMI부서와 가스켓부서에서 전자기파 차단제를 스프레이 도장하는 작업을 하였고, 3년 전부터 서서히 발생한 얼굴과 몸의 회색 및 회청색 피부색 변화를 주소로 내원하였다. 전자기파 차단제는 은, 구리, 용제들로 구성되어 있었다. 피부 조직 검사에서 에크린 한선 기저판(basal lamina)에 미세하고 둥근 흑갈색 과립들이 관찰되어 은피증의 소견을 보였으며, 작업중 노출된 은 흡입에 의한 직업성 은피증으로 진단하였다. 킬레이트 치료는 도움 되지 않으며, 노출 중단 및 자외선 차단 등의 보존적인 방법을 사용하고 있다. 고찰: 은피증은 은의 복용, 흡입, 접촉에 의해 발생한다. 본 증례에서는 은피증을 원인으로 작업시의 은 노출 이외의 은 노출을 발견할 수 없었다. 그러므로, 직업성 은피증으로 사료되며, 은의 첨가제에 의해 은피증이 발생 할 수 있음을 보여준다. 현재 전자기파 차단의 용도로 은과 은 화합물의 사용이 계속되고 있으므로, 이에 대한 대책이 필요하다고 본다. 적절한 치료법이 없기 때문에, 예 방이 가장 중요하며, 보호구 착용, 작업환경 개선, 산업 안전보건교육이 필요하다. Background: Skin contact with, and the breathing in of air containing silver compounds can occur in the workplace. Occupational exposure to silver and its compounds is mainly via airborne dust, metal fumes, and mists of solutions containing silver compounds. Argyria results from increased serum silver levels and the deposition of silver-containing particles in the dermis and mucous membranes. The author reports a patient with generalized argyria, who worked on the manufacture of cellular phone cases. Case report: The patient was a 30 year-old male, with extensive blue-gray discoloration of the whole body, especially sun-exposed area, of 3 years duration. He had been exposed to silver in the processing of EMI for the past 4 years and gaskets for 1 year. EMI is the process by which the internal electromagnetic wave in cellular phone cases are shielded, and gaskets play an important role in shielding the electric clashes between electronic circuits, as well as increasing the durability of cellular phone cases to impact. EMI had been processed manually but this was changed to automatic spraying by robots in 2003. On physical examination, the patient had diffuse blue-gray discoloration of the skin, which was most prominent in the sun-exposed areas of his face, neck and V of the chest. Histopathological examination of a punch biopsy specimen from the posterior neck revealed fine, minute, round, and brown-black granules deposited in the basement membrane zone surrounding the eccrine glands. The laboratory findings were positive for hepatitis B antigen, with a serum silver concentration of 150.3 ppb. From this evidence, he was diagnosed with argyria due to silver exposure. Discussion: The author reports a case of occupational systemic argyria due to inhalation exposure of silver compounds.

도시지역에서 선행강우지수를 고려한 저수유출 시뮬레이션 모형

허창환,임기석,송시훈,지홍기 대한상하수도학회 2003 상하수도학회지 Vol.17 No.1

This study is aimed at the development of a deterministic runoff model which can be used for low flow runoff. The model is formulated by the watershed runoff model. Based on the assumptions that runoff system is nonlinear, the proposed watershed runoff models are the conceptual model and artificial neural network model. In the model structures, the conceptual model divide the runoff system into a surface structure and a subsurface structure corresponding to the surface flow, and inter flow and ground water flow. The lag time effect of surface can be represented by the sub-tank of surface structure in the conceptual model. Fifteen neural networks models using Quasi-Newton technique were prepared to find the optimum parameters with each of them having different numbers of hidden layers and hidden layers nodes. The parameter calibration of inter flow and ground water flow in the subsurface structure of the conceptual model is made by separating the components with numeric filter. The runoff coefficient (α_2, K_1) is expressed as the function of antecedent precipitation index (API) in the conceptual model. The parameters related to the surface flow can be calibrated with the runoff coefficient (α_1, α_11, C_1, C_2) in the conceptual model. In the conceptual and ann model an algorithm are developed to calibrate the parameters automatically based on efficiency criteria. The conceptual model shows more closely to the observed hydrograph than ann model.

담관 낭선암 1례

박건욱,홍기봉,정재열,노명환,한상영,최석렬,신우원,나서희 동아대학교의과대학 1997 동아의대학술지 Vol.9 No.1

새로운 방법에 의한 1,1-R,R'-2,3,4,5-테트라페닐-1-실라사이크로펜타디엔의 합성

주완철,흥장환,최석봉 성균관대학교 기초과학연구소 1988 論文集 Vol.39 No.1

A new synthesis of 1,1-R, R',-2, 3, 4, 5-tetraphenyl-1-silacyclopentadiene was described. It was synthesized from one-pot reaction of 1,4-dilithio-1, 2, 3, 4-tetraphenylbutadiene with R_nSiCl_4-n (n=0, 1, 2), where 1, 4-dilithio-1, 2, 3, 4-tetraphenyl butadiene was prepared from the reaction of diphenyl acetylene and lithium metal in ether solution with good yield (80∼85%).

메치실린 내성 황색 포도상구균에 유효한 항생물질을 생산하는 방선균의 선별 및 물질생산조건

이동희,홍환석 건국대학교 산업기술연구원 1999 건국기술연구논문지 Vol.24 No.-

토양시료로부터 다제내성 MRSA에 유효한 항생물질을 생산하는 Actinomycetes 균주 LAM 98-90을 분리하여 동정한 결과 Streptomyces 속 균주였으며 spore chain은 spiral, spore surface는 smooth type이었고, 세포벽은 LL-DAP를 함유하였다. Aerial mass color는 회색이었으며 melanoid와 가용성 색소는 생성하지 않았다. 그리고 LAM 98-90에 의한 항생물질의 생산조건을 검토한 결과 탄소원으로는 soluble starch가, 질소원으로는 yeast extract, beef extract, peptone이 가장 우수하였으며 Mg²+ 첨가로 물질생산량이 많이 증가하였다. 생산 최적온도와 초발 pH는 각각 35℃와 7이었으며, soluble starch 2%, yeast extract 0.1%, beef extract 0.1%, peptone 0.1%, MgSO₄7H₂O 0.05%, K₂HPO₄ 0.05%, NaCl 0.05% 조성의 배지로 5일간 배양하였을 때 배양액내의 항생물질 축적량이 최대에 달하였다. LAM 98-90 균주가 생산하는 항생물질은 Gram 양성세균에 대해서는 항균활성이 우수하였으나 Gram 음성세균에는 비교적 약하였으며 진균류에는 전혀 작용하지 못하였다. An antibiotic producing strain LAM 98-90, effective to the multidrug-resistant MRSA, was isolated from soil. The spore chain of LAM 98-90 was spiral, and the spore sulface was smooth. LAM 98-90 has LL-diaminopimelic acid in the cell wall. The aerial mass color of the strain was gray, and the reverse side color was brown. The strain did not produce melanoid and other soluble pigments. And according to the Taxon program, LAM 98-90 was identified to one strain of Streptomyces. For the antibiotic production, soluble starch, soluble starch, yeast extract, beef extract and peptone were favorable as carbon and nitrogen sources. The antibiotic production was stimulated by the addition of Mg²+, but inhibited by Ag+, Co²+ and Fe²+ completely. Optimal temperature and initial pH for production of the antibiotic was 35℃ and pH 7, respectively. Accumulation of the antibiotic in the culture broth reached at maximal level after 5 days cultivation in the medium containing soluble starch 2%, yeast extract 0.1%, beef extract 0.1%, peptone 0.1%, K₂HPO₄ 0.05%, MgSO₄·7H₂O 0.05%, and NaCl 0.05%, and NaCl 0.05%. The antibiotic inhibited the growth of Gram positives well, however moderated for Gram negatives, and did not inhibit yeast and mold.