소형 물체의 검사를 위한 고해상도 미세 초점 X선 단층 촬영 시스템

구자용,김영주,이승석,김환우 韓國非破壞檢査學會 1998 한국비파괴검사학회지 Vol.18 No.3

광원의 직경이 5㎛ 수준인 X선을 이용하여 미세 초점 X-선 단층촬영장치(computerized tomography system)를 제작하고 제어 및 계산 프로그램을 개발하였다. 본 장치는 비파괴검사용으로서 직경20mm 이내의 시험체를 검사할 수 있다. 단층영상을 얻기 위한 계산 알고리즘으로서는 convolution back projection 알고리즘을 사용하였으며 광원의 형상을 평행 빔과 부채꼴 빔(fan beam)등 두 종류를 사용하여 결과를 비교하였다. 장치의 제어 및 계산은 개인용 컴퓨터에서 동작하도록 하였다. 제작된 CT 장치와 프로그램을 이용하여 제작된 시편에 대하여 단층 영상을 복원하고 시편의 내부 구조 및 결함을 관찰하였다. 단층영상을 얻은 결과 실제 모습과 일치하는 재료내부의 결함에 대한 정보를 얻을 수 있었으며 해상도는 20~30㎛정도인 것으로 판단되었다. A computerized tomography system was developed using the X-ray source that has diameter of 5 micrometer. The system is used for the nondestructive testing of specimens with diameter below 20mm. The convolution back projection algorithm was adopted for the reconstruction of cross sectional image, and the shape of the X-ray beam was let parallel beam or fan beam to compare each resultant image. Our CT system was constructed to operate based on the personal computer. The sectional images of the fabricated specimens were reconstructed and analyzed. The reconstructed images well coincided with real images taken with optical microscope and gave us enough reports on the defects in the ceramic specimen. The resolution of the system regarded as about 20~30 micrometers.

은행원의 VDT작업에 따른 안자각종상

구정완,이승환,이자영 가톨릭대학산업의학쎈타 산업의학연구소 1991 韓國의 産業醫學 Vol.30 No.5

In order to investigate the effects due to visual display terminal(VDT) work of banking operations, the questionnaire survey for subjective eye symptoms was carried out on 378 bank clerks who had been engaged in VDT work for various length of work hours. The results were as follows: 1. Of the 17 items of questionnaire, the highest percentage was accounted for by 'eye strain' (61.1%),follwed by 'feel pressure in eyes'(33.3%),'eyes feel ache' (26.7%),'eyes feel heavy'(21.4%) and 'blurred vision of objectl'(16.7%) in the order of sequence. 2. The average weighetd score of subjictive eye symptoms was 13.75, 14.39, 16.78 and 13.13 in the age groups of less than 25,25-29, 30-34, and 35-44 years, respectively, it was significantly increased from the age group of less than 25 years to 30-34 years. Also, it was significantly increased according to increasing with work duration. 3. The average weighted score of female was larger than that of male and the score of green color was larger than that of black-white color by the color of cathode ray tube display. 4. Aggravating time of subuective symptioms was during the end of month in period of a month, a monday in a day of week and on duty (P.M.) in a daily work.

강의 현대화 추진 및 활용방안 연구

구경완,이근복,장종국,김재홍,김영환,최제영,이승훈 永同大學校 1997 硏究論叢 Vol.3 No.1

본 연구는 각종 첨단 기자재를 활용한 강의 현대화 방안을 모색함으로서 공학교육의 효율성을 도모하고 학생들의 학습동기를 유발하여 창조적 능력을 갖츤 전문기술 인력을 양성하는 데 도움을 주고자 하는 것이다. 이를 위하여 현행 공학교육의 현황과 문제점을 분석하고 강의 현대화 사례를 조사하여 본 연구의 기초자료로 삼고자 하였으며, 학부·전공별 강의 현대화 추진 실태분석 및 개선방안을 모색한 후 이상의 연구결과를 종합하여 향후의 강의 형대화 추진방향을 걸정하였다. This study aims to help bring up the well-skilled and creative engineers by searching the modernization of education using various high technology facilities. For this, we analyzed the general condition and problems of current engineering education and surveyed the case study of the modernization of education as basic study. After analyzing the existing situation of promotion searching the proper improvement methods of it, we proposed the new direction of the modernization of education from now on.

Poly(4,9-di(p-acetylphenyl)diadamantane)의 합성

具廣謨,具承榮,張晋圭 慶一大學校 1996 論文集 Vol.13 No.2

4,9-Di(p-acetylphenyl)diadamantane monomer was synthesized by Fridel-Craft acetylation on 4,9-phenyldiadamantane with acetyl chloride in CS². The 4,9-diphenyldiadamantane was prepared from diadamantane and benzene in the presence of t-butyl bromide and AlCl³. The polymerization of the difunctional ketone, 4,9-di(p-acetylphenyl)diadamatane monomer under McMurry coupling reaction condition gave white powderic polymer. The chemical structure of the resulting polymer was characterized by ¹H NMR, ¹³C NMR, IR and TGA. Oligomeric polymers were slightly soluble in halogenated solvents, and the polymer was almost insoluble in any organic solvent. The temperatures of 10% weight loss were 492℃ under nitrogen and 429℃ in air at a heating rate 20℃/min.

수지상 내생균근 Glomus Etunicatum의 접종이 석탄폐광지 토양에 식재한 아까시나무의 생육 및 생리에 미치는 영향

홍승진,임경민,박용우,구창덕,우성민 忠北大學校 農業科學硏究所 2012 農業科學硏究 Vol.28 No.2

본문참고

멀티미디어 제작을 통한 초등 정보영재교육에 관한 연구

남승현,배영권,김도윤,구덕회,이태욱 한국컴퓨터교육학회 2005 컴퓨터교육학회 논문지 Vol.8 No.2

협기성 생물막 반응기의 초기 운전특성

이승란,김도한,나영수,이창한,박영식,윤태경,송승구 한국환경과학회 2002 한국환경과학회지 Vol.11 No.3

The lab-scale anaerobic continuous reactor which was filled with the sludge of anaerobic digestion from Suyoung wastewater treatment plant was operated by feeding of various concentrations and flow rates. This experiment indicated that more than 6,870 ㎎COD/L of substrate concentration was required to promote good metabolism and growth of anaerobic biomass. And increasing loading rate slowly was also required in order to treat substrate of higher concentration and higher loading rate. The substrate concentration of about 10,000 ㎎COD/L was adequate to generate biogas efficiently. The pH was sharply decreased at the onset of higher loading rate, but the pH was restabilized soon at 8. During the experiment, the amount of the attached biomass was kept constant.

폐 활성 슬러지의 납 흡착에 따른 기초 요소의 영향

강미영,서정호,이창한,이송우,나영수,송승구 부산대학교 환경문제연구소 1998 環境硏究報 Vol.16 No.-

본 연구에서는 하수 처리장에서 발생되는 상당량의 폐 슬러지를 전처리 없이 중금속 제거에 사용하였다. 본 연구의 목적은 폐 슬러지를 이용하여 중금속을 제거하는 것이다. 온도와 pH, 초기 농도의 영향과 보관 시간에 따른 납 흡착량의 영항을 흡착등온 모델과 흡착속도 모델에 적용시켜 활성슬러지의 납 흡착 특성을 고찰하였다. 납, 카드뮴, 크롬, 니켈 중 슬러지는 납을 가장 많이 제거하였고, pH 4.5~5.5에서 최대의 흡착량을 나타냈으며, 온도가 증가할수록 흡착량은 증가하였고, Langmuir model에 잘 적용되었으며, 초기 최대 흡착속도도 Michaelis-Menten 형태 식으로부터 구하였다. In sewage treatment plant, waste sludge was one of bothering thing to be treated. The objective of this study was to examine the removal of heavy metal by waste sludge. The effect of factors such as temperature, pH, storage time, initial concentration of lead, and initial amount of biomass on adsorption of lead was investigated. And the biosorption model, adsorption isotherm, and initial adsorption rate model were evaluated. Waste sludge was proved to have an excellent ability to remove lead than other heavy metals such as cadmium, chromium, nickel in pure and mixed solution. The optimum pH of biosorption with waste sludge was 4.5~5.5, and the amount of adsorption was increased with increasing temperature. The adsorption isotherm of lead to waste sludge followed to Langmuir model. The initial adsorption rate of lead to waste sludge followed to Michaelis-Menten type kinetic.

운동수행 및 회복기의 순환계 반응과 요성분 변화

위승두,이재엽,서영환,구희성 朝鮮大學校 스포츠科學硏究所 2004 스포츠科學硏究 Vol.15 No.-

The purpose of this study was to investigate the effect of routine jogging exercise on cardiorespiratory function and blood lipid and urine components change in 40 year's Korean men. The subjects consisted of 20 middle-aged routine jogging group participated 30~40 min at 70% of the heart rate max 3-4 days per week 1 year more and 20 control group. The results of this study were as follows; 1. The HR rest was decreased and HR max was increased by routine jogging group while no significance existed. Vo_(2) max was significantly increased in routine jogging grouP(p<0.05) while SBP and DBP were not changed. 2. Fat% was not significantly decreased in jogging group. 3. pH in urine showed no change among the jogging group, but the control group showed a slight change from 5.0 to 7.2. For the control group, specific gravity (S.G.) was 1.018 at rest, 1.029 after exercise, for the jogging group specific gravity was 0.1818 at rest, 1.022 after exercise. 4. The protein change was negative for all subjects but two of them was trace after exercise. The change of glucose, bilirubin, urobilinogen, and ketone body was also normal for all subjects before and after exercise. This result indicate that routine jogging exercise decreases the risk of degenerative disease. 40 year's middle-aged man must improve theircardiorespiratory function to protect and recover degenerative disease.

저진동 저소음을 위한 기어시스템의 서계 자동화 연구

尹救永,柳承玹 홍익대학교 산업기술연구소 1998 産業技術 Vol.8 No.-

Minimizing vibration of a reduction gear system, has frequently been the focus of many studies as well as for a good, efficient strength design of reduction gear elements. This work presents new reduction gear system design for reducing vibration and fully automated determination of machine elements with a G.U.I technique. A new CAD simulation is based on minimizing Transmission Error (T.E) of the reduction gear system, which is understood as a principal factor of gear vibration and noise. Also using the Visual C++ Language, new G.U.I computer simulation is developed for the reduction gear designer who are not much experienced in the work. The procedure of new CAD program assures the reliability of the traditional reduction gear system design, and more uniquely considers the better performance in the vibration. The new method can be applicable to all machinery design with a reduction gear system on condition that the machine elements have been analyzed in the point of strength.