흰쥐에서 말초신경 손상후 뒤뿌리신경절세포의 신경영양인자와 그 수용체의 발현 양상

백선용,양만석,문총석,김봉선,김재봉,김진정 대한해부학회 1999 Anatomy & Cell Biology Vol.32 No.2

수인성 바이러스의 수계환경내 분포실태 및 검색방법론

정용석 慶熙大學校 地球環境硏究所 1998 지구환경논문집 Vol.9 No.-

나노결정 실리콘의 전기적 특성에 관한 연구

정서용,최석호 慶熙大學校 레이저 工學硏究所 1997 레이저공학 Vol.8 No.-

DC conductivity measured for nanocrystalline Si(nc-Si) deposited by remote plasma chemical vapor deposition(RPCBD) exhibited the Meyer-Neldel rule(MNR). Basic experimental results indicate that the electrical and optical properties of the RPCVD nc-Si films do not follow the quantum size effects, but strongly depend on the sample preparation conditions, largely on the substrate temperature. We found that the MNR parameters, almost independent of the bias voltage 2.4x10??(ohm . cm)??, 55 meV at a bias of 10V. In samples soaked by a white light of 100 mW/㎠ for one hour, the slope of the MNR increased by 4.6 eV??. The quantitative resemblance of the MNR to the one found in hydrogenated amorphous silicon(a-Si:H)indicated that the conduction in nc-Si films takes place in a a-Si:H-like tissue that wraps the luminescent crystallites.

정보통신분야 국가기술자격증 취득과 정보통신공학 전공 학생들의 취업률 증진을 위한 방안

정기석,민경일,조용석,신용달 永同大學校 1997 硏究論叢 Vol.3 No.1

본 연구에서는 정보통신분야 국가기술 자격증 취득과 정보통신전공학생들의 취업률증진을 위한 방안을 제시하고 그 결과를 고찰하였다. 국가기술자격증 취득방안으로는 동기부여, 특강별로 한 과목씩 단계적인 강의 등의 방법을 제시하였고, 취업률 증진 방안으로는 학생수준에 맞는 업체선정지고, 취업자료 수집, 업체방문 등의 방법을 제시하였다. 연구결과는 업체의 요구조건은 공통적으로 어학증명서와 기술자격증으로서 대기업에 취업하기 위해서는 어학실력이 좋아야 하며 따라서 TOEIC등의 시험을 적극 권장할 필요가 있음을 보여준다. This paper examines a plan for acquiring a technical qualification and promoting the percentage of employment in Information & Communication Engineering Major. As a plan for acquiring a technical qualification, study methods of a motive allowance, step lesson of a curriculum etc. are presented. Also, as a plan for promoting the percentage of employment, study methods of a collection of employment data, company visit etc. are presented. Results of study show that companys require a technical qualification and a certificate of foreign language, so TOEIC should be recommended.

이동 열원을 고려한 전자빔 용접의 유한요소해석

조해용,정석영,김명한,조창용,이제훈,서정 한국레이저가공학회 2001 한국레이저가공학회지 Vol.4 No.1

Simulation on the electron beam welding of Al 2219 alloy was carried out by using commercial FEM code MARC, which encounters moving heat sources. Due to axisymmetry of geometry, a half of the cylinder was simulated. A coupled thermo-mechanical analysis was carried out and subroutine for heat flux was substituted in the program. The material properties such as specific heat, heat transfer coefficient and thermal expansion coefficient were given as a function of temperature and the latent heat associated with a given temperature range is considered. As a result, the proper beam power is 60kVX60mA and welding speed is 1~1.5 m/min. The residual stress in the heat-affected zone as well as the fusion zone does not increase. It is necessary to use jigs for preventing distortion of cylinder and improving weld quality.

누설전류 파형 측정에 의한 실리콘 고무의 표면 열화 평가

김정호,정규원,서광석,유영식,박용관 成均館大學校 科學技術硏究所 1999 論文集 Vol.50 No.1

In this study, we investigated the erosion resistance of the silicone rubber by measuring leakage current with Inclined-Plane Method. From the results of our study, it was observed that the typical leakage current waveform was the mixed figure of sinusoidal wave and rectifying wave. And, it is considered that the former is due to conductivity of the contaminant when the surface is wet, and the latter is due to the arc discharge of dry band. And, as the surface erosion is being accelerated, the proportion of the rectifying wave is increasing. And, the ratio of discharge duration to discharge-extinguish time changes and can be divided into three regions, which is similar to the changes of erosion depth and width. Therefore, it can be known that the erosion process has some correlation with the change of leakage current.

레저스포츠 참여와 여가만족의 관계

김용인,정갑석,장호중,김정묵,정석현 한국스포츠리서치 2004 한국 스포츠 리서치 Vol.15 No.1

The purpose of this study was to examine the relationship between participation in leisure sport activities of leisure satisfaction. To accomplish this research purpose, there were two research questions; Firstly, Is there difference on leisure satisfaction according to the participation in leisure sport activities?, Secondly Will the degree of participation in leasure sport activities influence the leisure satisfaction? The population for this study was participants in Leisure sports activity program located in Seoul. The final 227 responses (participation 163, non-participation 114), collected by cluster random selecting method, were used in the data analysis procedure. The items for measuring leisure satisfaction were largely based on Lee(1992)s study, and the degree of participation in leisure sport activities was measured by the period and frequence of participation. To analyze the final data (277), the reliability analysis, analysis of covariance, multiple classification analysis, and multiple regression analysis were used. The conclusions for this study were as followings; Firstly, leisure satisfaction is partially different by participation yes or no of the leisure sports activity. That is, leisure satisfaction is higher participation of leisure sports activity than non-participation Secondly, leisure satisfaction is partially influence by the participation of degree of leisure sports. That is, period and frequence are influence on leisure satisfaction.

인공 치아우식 발생 모델에서 디지털 방사선 공제술을 이용한 인접면 치아우식증의 진단

박정훈,최용석,황의환,이기자,최삼진,박영호,김경숙,진현석,홍경원,오범석,박헌국 대한구강악안면방사선학회 2009 Imaging Science in Dentistry Vol.39 No.1

Purpose : The purpose of the experiment was to evaluating the diagnostic ability of dental caries detection using digital subtraction in the artificial caries activity model. Materials and Methods : Digital radiographies of five teeth with 8 proximal surfaces were obtained by CCD sensor (Kodak RVG 6100 using a size #2). The digital radiographic images and subtraction images from artificial proximal caries were examined and interpreted. In this study, we proposed novel caries detection method which could diagnose the dental proximal caries from single digital radiographic image. Results : In artificial caries activity model, the range of lesional depth was 572-1,374 μm and the range of lesional area was 36.95-138.52mm². The lesional depth and the area were significantly increased with demineralization time (p<0.001). Furthermore, the proximal caries detection using digital subtraction radiography showed high detection rate compared to the proximal caries examination using simple digital radiograph. Conclusion : The results demonstrated that the digital subtraction radiography from single radiographic image of artificial caries was highly efficient in the detection of dental caries compared to the data from simple digital radiograph.

발전기 안정화 운전을 위한 PSS 파라미터 선정

김창석,황석영,서진연,정삼용 조선대학교 동력자원연구소 1995 動力資源硏究所誌 Vol.17 No.1

This paper describes the proper selection method of the power system stabilizer(PSS) parameter for stabilizing operation of a synchronous machine which connected to infinite bus by using pole assignment method. The purpose of PSS is to enhance the damping capability at small frequency oscillation (0.5∼2㎐). It can be achieved by moving the real part of critical eigenvalue (pole) on left side of s-plane. The PSS parameter was selected by using the proposed method to match with a pre-assigned pole associated with poorly damped swing mode. This method has been studied to synthesize the PSS on Yong-Gwang N/P. And the simulation results show that the selected parameter by using proposed method is effective for dynamic and transient stability of power system.

降水物 tritium濃度의 年中變化

蔡貞淑,尹柱庸,田載植 충남대학교 자연과학연구소 1983 忠南科學硏究誌 Vol.10 No.1

A series of measurements of tritium concentration in precipitation has been carried out at the College of Sciences, Chungnam National University for a period of one year from March 1982 to February 1983. Samples were taken from every precipitation and processed through electrolytic enrichment for liquid scintillation counting of tritium activity. Results are summarized in a table and figure which shows a rough periodicity in the annual variation of tritium concentration with a maximum monthly mean of 1318±197 TR in April 1982 and a minimum of 220±37 TR in July of the same year.