나선형 이중 평행판 축전기형 Blumlein 전송회로를 사용한 소형 질소레이저의 동작 특성 연구

양준묵,이치원,조돈수,이봉연 충남대학교 기초과학연구소 1995 忠南科學硏究誌 Vol.22 No.1

The design and performance of a compact nitrogen laser which consists of a Spiral multiple parallel plate capacitor type Blumlein transmission line circuit are described. The laser tube is made by 50 ㎜ long with a 2.5 ㎜ main electrode gap spacing. The output power increased with the spark gap distance. The peak power of 3.0 μJ has been obtained with a spark gap distance of 3.5 ㎜ and a repetition rate of 30㎐. The optimum nitrogen gas pressure was about 60torr independent of the variation of spark gap distance. The laser operates with repetition rate of up to 70 ㎐.

충남대학교 연습림의 산책로 훼손에 관한 연구

이준우,박범진,최윤호 충남대학교 농업과학연구소 1998 농업과학연구 Vol.25 No.1

Three major trails of campus forest in Chungnam National University were selected to investigate the use impacts on environmental deterioration of trail according to the different amount of use. Rook-exposed, root-exposed, deepening, widening, diverged points as the deterioration types of trail which were surveyed at total of 92 points in major trail of campus forest in Chungnam National University. Major deterioration types of trail were widening, rock-exposure, root-exposure, in order of frequency. And trail conditions(trail slope and maximum depth) of deteriorated points were significantly different from those of non-deteriorated points.

Blumlein 전송회로에 의해 선전리되는 질소레이저의 동작특성 연구

양준묵,추한태,이봉연,이치원 충남대학교 1990 忠南科學硏究誌 Vol.17 No.2

The design and construction of nitrogen laser preionized with a Blumlein transmission line circuit is described. For the power supply, we have used a pulse type high voltage power source that can be produce 10 joule energy in a pulse. The condition of maximum output power is observed at N_2 gas pressure of 100 torr, spark gap distance of 6.0 mm, repetition rate of 30Hz with preionization, and the stability increases by 0.7%. The maximum increment of output power is achieved at pressure of 200 torr when preionization is used. Finally we can increase the output power by approximately 60% by using this work, and the E/P value is 133 V㎝^(-1) torr^(-1).

충남대학교 학술림 산책로 훼손실태 및 관리방안에 관한 연구

이준우,김명준,최윤호,전용준,오도교,김민호,이소연,이경형 충남대학교 농업과학연구소 2004 농업과학연구 Vol.31 No.2

This study concentrates an the trail of the CNU(Chungnam National University) forest. The amount of use and the pattern of damage are considered, as well as the extent of environmental damage. Finally, some managerial strategies are proposed in connection with sustainable maintenance. The trail of the university forest is composed of three sections; one is the neighborhood park and the Institute of Information Technology/Communications, the second is the Institute of Information Technology/Communications and the Dormitory, and the third section is the Dormitory and the Foreign prof's Apt. The total length of the trail is 2.6km. The daily amount of use is 1,269 visitors per day. The amount of using increased three times the amount of that in 1998. This study shows the pattern of damage of the trail in the order of root-exposure, widening, rock-exposure, deepening and the divergence in the frequency of occurrence of all these factors. Environmental damage is also graded thus: grade 3 is 27.4m, grade 4 is 0.8m, grade 5 is 1.5m, and grade 6 is 0.2m. Accordingly, some managerial strategies were proposed in connection with the sustainable trail maintenance.

히스테리시스 효과의 컴퓨터 시뮬레이션

류연국,양계준,한운동,박용만 충주대 산업과학기술연구소 1993 産業科學論文集 Vol.1 No.-

Usefulness of recent versions of PSPICE, personal computer implementation of the SPICE, circuit simulation computer software rogram is demonsterated in simulation of the hysteresis loops magnetic materials. In order to model the hysteresis loop of a particular magnetic core's B-H characteristics, the values of five parameters, which affect the shape of the hysteresis loops, must be established. There is no efficient procedure for selecting the values of five parameters. Neither the PSPICE instruction munual nor any current books or papers address this problem. This paper presents a method for illustrating the effect that each parameter has on the shape of the hysteresis loop.

Clostridium difficile에 의한 설사의 예후인자

김준형,김희정,구남수,김영근,최준용,신소연,박윤선,김연아,김명수,정수진,최희경,송영구,이경원,김준명 대한감염학회 2007 감염과 화학요법 Vol.39 No.2

배경 : Clostridium difficile에 의한 설사(Clostridium difficile associated diarrhea; CDAD)는 임상 경과가 다양하다. 최근에 유럽과 북미에서 C. difficile 감염의 발생률이 증가하고 고전적 치료에 잘 반응하지 않으며 이환률이 증가하였고, 이러한 원인이 새로운 균주의 탄생에 기인한다고 보고되었다. CDAD의 예후에 영향을 미치는 세균성 요인과 숙주 요인을 확인하기 위해 본 연구를 진행하였다. 재료 및 방법 : 2002년 8월부터 2003년 12월까지 CDAD가 진단된 20세 이상인 환자들을 대상으로 후향적 Cohort 연구를 하였다. 세균성 요인을 확인하기 위해 cdt A, cdtB, tcd A, tcd A rep 그리고 tcd B 유전자(binary toxin)를 확인하였다. 설사가 치료 시작 후 11일 이상 지속되거나, 2달 이내에 재발하거나, 수술 혹은 다른 시술이 필요한 경우, 사망한 경우 예후가 좋지 않은 것으로 정의하였다. 결과 : 총 115예에서 toxin을 생성하는 C. difficile가 동정되었으며, Toxin A와 toxin B 모두 양성인 균이 91예, toxin B만 양성인 균이 24예였다. Toxin A 생성 여부가 예후에 영향을 미치지 않았지만, 제산제를 사용한 환자에서 그렇지 않은 환자에 비해 toxin B만 양성인 균이 많이 동정되었다(P<0.05). 예후가 좋지 않은 경우는 39예(33.9%)였고 76예(66.1%)에서 예후는 양호하였다. 단변량 분석에서 70세 이상의 고령, 남성, 증상 발현 후 사용한 항생제의 개수 사용, 증상 발현 후 carbapenem, aminoglycoside, glycopeptide 사용, 당뇨 및 뇌졸중 병력이 있는 경우, 그리고 높은 Charlson index가 불량한 예후 인자로 확인되었다. 그러나 독립적인 예후 인자를 조사했을 때에는70세 이상의 고령(odds ratio=3.378, P=0.009), 증상 발현후 carbapenem 사용(odds ratio 7.210, P<0.001)이 예후에 중요한 영향을 미치는 요소로 확인되었다. 결론 : 70세 이상의 고령과 증상 발현 후 carbapenem 사용이 CDAD 독립적인 불량한 예후인자이다. Background : Clostridium difficile associated diarrhea (CDAD) has a wide range of clinical manifestations. The prognostic factors of CDAD are not fully understood. Materialsand Methods : A retrospective cohort study of 115 patients with CDAD from Aug. 2002 to Dec. 2003 was conducted to evaluate prognostic factors of CDAD. Bacteriologic factors were determined by detecting the binary toxin gene, tcd A, tcd A rep and tcd B gene. Poor prognosis was defined as diarrhea more than 10 days even with classic treatment, recurrence, death, and moribund discharge. Results : Approximately 79% of isolated strains were toxin A+/B+ strains and 21% were toxin A-/B+ strains. There was no difference in prognosis between toxin A+ and toxin A- strains. 39 (33.9%) cases showed poor prognosis and 76 (66.1%) cases showed good prognosis. Univariate analyses revealed that the poor prognostic factors were old age over 70 years old, male, the number of antibiotics used after onset of symptom, the administration of carbapenems, aminoglycosides, glycopeptides after onset of symptom, history of DM and stroke, and high Charlson comorbidity index. Multiple logistic regression analysis identified old age over 70 years old (odds ratio=3.378, P=0.009) and the administration of carbapenems after onset of symptom (odds ratio 7.210, P<0.001) as the independent poor prognostic factors. Conclusion : Old age over 70 and the administration of carbapenems after onset of symptom were the poor prognostic factors for CDAD caused by none-binary toxin producing strains.

마이크로 압전 엑츄에이터용 Sol-Gel PZT 박막의 두께 변화에 따른 특성

장연태,박준식,김대식,박효덕,최승철 호서대학교 반도체제조장비국산화연구센터 2001 반도체장비학술심포지움 Vol.2001 No.-

Pb가 10% 과잉되고 Zr : Ti = 52 : 48 조성을 갖는 PZT sol이Pt(3500A˚)/Ti(400A˚)/SiO2(3000A˚)/Si(525㎛)기판 위에 스핀 코팅법으로 반복 코팅된 후, 450℃에서 10분, 650℃에서 2분간 반복 열처리되었다.이와 같이 다양한 두께로 적층된 박막은 각 시편에 대해 최종적으로 650℃ 30분 동안 어닐링 처리되었다.제조된 PZT 박막의 두께는 4100A*에서 1.75㎛사이의 4종이었다.이어서 스퍼터링법으로 Pt전극이 PZT 막 위에 증착되었다.제조된 PZT 박막의 결정 구조 조사를 위해 XRD, 그리고 미세 구조 및 전기적 특성을 알아보기 위해 FESEM과 P-E 이력 곡선이 각각 관찰되었다.4100A˚에서 1.75㎛까지 두께 중가에 따른 장비상의 포화 이력 한계로 잔류 분극(Pr)값이 25A˚u C/㎠에서 다소 감소되었다.측정된 X선 회절 결과에서 최초 4회 코팅시 perovskite 결정 구조로 성장한 결정립은 (111)배향이 우세하였으나, 두께가 증가됨에 따라 (111)/(110)값이 감소되었으며, 이를 통해 두께 증가에 따른 (111)배향성이 다소 감소됨을 알 수 있었다.이상의 결과로부터 제조된 PZT 박막은 큰 힘과 높은 내전압 특성을 갖는 마이크로 압전 액츄에이터에 적용될 수 있을 것으로 생각되었다.

先電離 窒素레이저에 의하여 펌프된 色素레이저

양준묵,추한태,이봉연 충남대학교 1991 忠南科學硏究誌 Vol.18 No.2

A preionized nitrogen laser with average output power of 3.0 mW in repetition rate of 30 Hz was constructed to be used as a pump for dye lasers such as rhodamine 6G, rhodamine B, coumarin 120 and coumarin 102. Under the optimum dye concentrations and wavelengths, dye laser average output power of rhodamine 6G, rhodamine B, coumarin 120 and coumarin 102 were obtained to be 1.6 mW, 1.1 mW, 1.1 mW respectively. According as nitrogen laser average output power was increased up to 76% by preionization effect, dye laser average output powers of rhodamine 6G, rhodamine B, coumarin 120 and coumarin 102 were increased up to 23%, 38%, 57% and 71% respectively. The nitrogen laser system used for this research can be utilized in dye lasers covering the entire visible spectra and if the nitrogen laser output power is improved, the output power of the coumarin 102 dye laser can be improved higher than that of the rhodamine 6G dye laser.

Styrene-co-lithium methacrylate ionomer의 기계적인 성질에 미치는 LiCl의 영향

나연화,김준섭,유지강,박기주 조선대학교 생산기술연구소 1999 生産技術硏究 Vol.21 No.2

The effect of LiCl salt added to styrene-co-lithium methacrylate ionomer on the mechanical properties of ionomers was studied dynamic rnschanically. When the LiCl salt was added to a 100% Li-neutralized ionomer, the amount of added salt. in the range of 100-300% to ionic groups of the ionomer, did not change the mechanical properties of the ionomers, This implies that the added salt may form isolated LiCl salt aggregates in the polymer matrix. However, when LiCl was added to a 200% neutralized ionomer, the cluster T_(g) shifted to a low temperature and then the sample started to flow. This result suggests that in this case the LiCl salts reside in and near the multiplets, resulting the weakening of ionic interactions between ionic groups in multiplets.

춘천시의 지하 저장 탱크의 예비적 위해성 평가를 위한 설치 현황 분석 및 지리정보시스템의 적용

김준현,한영한,이종춘,권영성,이광연 江原大學校 産業技術硏究所 2002 産業技術硏究 Vol.22 No.A

In this study, the preliminary risk assessment for the underground storage tanks(UST) in Chunchon city was implemented using the geographical information system(GIS). The estimation variables, such as the installation year, storage capacity, the distances from streams, and from groundwater pumping wells, were selected to estimate the relative risk levels. The weighting factors were given to all the estimation variables. Cumulative scores were induced by the combination of al1 the scores of the corresponding variables using the buffering technique and the overlay analysis in ArcView. Using the these process, the relative risk level of each UST was estimated. Some sites in this study are simplified and reduced because the number of useable data are limited or too enormous. Thus the selection of the comprehensive estimation variables and the proper weighting values are required for the future study. The methodology in this study could be served not only for the preliminary risk assessment of UST but also for the selection of the proper location of new and old UST. And, it can be used for the effective management system of UST.