전국 10개 종합병원 중환자실 환자의 직장내 Vancomycin-resistant Enterococci(VRE) 보균율, 보균의 위험요인 및 유전적 다양성 조사

정희진,송준영,엄중식,김우주,최선주,최정현,이혁,정문현,이광미,신동현,손보라,최종성,우흥정,권정아,이경원,최강원,박승철 대한감염학회 2002 감염 Vol.34 No.5

간척지에 있어서 목초의 내염성 비교

최원열,최기춘,전우복 全南大學校 農業科學技術硏究所 1996 農業科學技術硏究 Vol.31 No.-

This study was conducted to compare the degree of salt tolerance as kinds of pasture plants in reclaimed coastal land. The experiment was designed with 10 cultivars of pasture plants and salt concentration of three levels. DM yields of perennial ryegrass, tall fescue, tall wheatgrass and alfalfa were higher than those of orchardgrass, birdsfoot trefoil and ladino clover at low salinity. Pasture plants were not grown at high salinity treatment and DM yields of pasture plants at medium salinity was lower than that of low salinity treatment. The growth of perennial ryegrass, tall fescue, tall wheatgrass and alfalfa was better than that of others in reclaimed coastal land.

실증주의에 관한 연구

최우원 釜山大學校 1997 人文論叢 Vol.50 No.1

고등학교 과학 동아리 활동 경험이 학생들의 진로선택에 영향을 준 사례 연구

최원호,우규환,박현주 한국과학교육학회 2004 한국과학교육학회지 Vol.24 No.6

학교밖 과학교육과 과학 동아리 활동에 적극적으로 참여한 경험을 가지고 있는 이공계 전공 대학생과 과학동아리 지도교사를 대상으로 과학 동아리 활동과 활동에 대한 인식을 조사하였다. 과학에 흥미와 재능을 가지고 있는 학생들이 1)직업적 역할 모델로서의 열정 있는 교사의 지도를 받으며, 2)직접적 체험을 경험하며, 3)오랜 기간 동안 과학실험을 준비하여, 4)비슷한 재능과 흥미를 가진 또래의 과학 동아리들 앞에서 발표하는 경험은 학생들을 과학관련 진로로 격려하는 좋은 요인임을 알았다. 또한 연구 참여자들은 과학 동아리 활동이 인생의 진로를 선택해야하는 중요한 시기에 과학에 대한 긍정적인 태도 형성에 영향을 주었고, 자신들의 학문적 진로를 결정하는데 중요한 영향을 주었다고 믿었다. This study is the analysis of interview with science major student about the effect of science club experience on career decision. The special interview was planned and arranged to meet students as well as their teacher. Both of the student whose background had experience in the science club activity, field science education during their high school days are majoring in physics and biology. In Summary : 1) science teacher's guidance deeply impressed the student that they respect the teacher as a occupational role model. 2) they really enjoyed the hands-on activities joyful. 3) their experience lasted so long time to keep them to stay in science field. 4) they had an experience of speaking before peer science club students who had similar interest and talent. We found the above four factors were really influential to encourage the subject to major in science career.

적외선열화상장치를 이용한 Buchanan plugger 표면의 온도상승 분석

최성아,김선호,황윤찬,윤창,오병주,최보영,정우남,정선와,황인남,오원만 大韓齒科保存學會 2002 Restorative Dentistry & Endodontics Vol.27 No.4

This study was performed to evaluate the temperature rise on various position of the Buchanan plugger, the peak temperature of plugger's type and the temperature change by its touching time of heat control spring. The heat carrier system 'System B' (Model 1005. Analytic Technologies, USA) and the Buchanan's pluggers of F, FM, M and ML sizes are used for this study. The temperature was set to 200℃ which Dr. Buchanan's "continuous wave of condensation" technique recommended on digital display and the power level on it was set to 10. In order to apply heat on the Buchanan's pluggers, the heat control spring was touched for 1, 2, 3, 4 and 5 seconds respectively. The temperature rise on the surface of the pluggers were measured at 0.5 mm intervals from tip to 20 mm length of shank using the infraed thermography (Radiation Thermometer-IR temper, NEC San-ei Instruments, Ltd, Japan) and TH31-702 Data capture software program (NEC San-ei Instruments, Ltd, Japan). Data were analyzed using a one way ANOVA followed by Duncan's multiple range test and linear regression test. The results as follows. 1. The position at which temperature peaked was approximately at 0.5 mm to 1.5 mm far from the tip of Buchanan's pluggers (p<0.001). The temperature was constantly decreased toward the shank from the tip of it(p<0.001). 2. When the pluggers were heated over 5 seconds, the peak temperature by time of measurement revealed from 253.3±10.5℃ to 192.1±3.3℃ in a touch for 1 sec, from 218.6±5.0℃ to 179.5±4.2℃ in a touch for 2 sec, from 197.5±3.0℃ to 167.6±3.7℃ in a touch for 3 sec, from 183.7±2.5℃ to 159.8±3.6℃ in a touch for 4 sec and from 164.9±2.0℃ to 158.4±1.8℃ in a touch for 5 sec. A touch for 1 sec showed the highest peak temperature, followed by, in descending order, 2 sec, 3 sec, 4 sec. A touch for 5 sec showed the lowest peak temperature (p<0.001). 3. A each type of pluggers showed different peak temperatures. The peak temperature was the highest in F type and followed by, in descending order, M type, ML type. FM type revealed the lowest peak temerature (p<0.001). The results of this study indicated that pluggers are designed to concentrate heat at around its tip, its actual temperature dose not correlate well with the temperature which Buchanan's "continuous wave of condensation" technique recommended, and finally a quick touch of heat control spring for 1 sec reveals the highest temperature rise.

재조합 균주 Bacillus subtilis LKS88에 의한 Streptomyces albus KSM-35 Amylase의 생산조건

최원진,유도진,이재우,소명환,김영배 한국식품영양학회 1998 韓國食品營養學會誌 Vol.11 No.4

Streptomyces albus KSM-35의 amylase의 유전자를 Bacillus subtilis LKS88에서 발현시킨 균주를 사용하여 amylase의 생산에 미치는 몇가지 요인들을 조사하였다. 본 실험에 사용한 탄소원들중에서 sodium citrate와 왕겨의 효소 생산량이 가장 높았고, 이들을 1:1의 비율로 혼합하여 첨가하였을 때 효소의 생산량은 대조군으로 사용한 가용성 전분에 비하여 20배 이상 증가하였다. 질소원으로 대두박을 사용하였을 경우 yeast extract의 첨가량을 줄이면서 효소의 생산량을 증가시켰다. 배양을 위한 초기 pH를 60으로 조절하고 SDS를 0.01%첨가하였을 때 대조구조보다 높은 효소 생산량을 나타내었다. Bacillus subtilis LKS88 (pASA240)을 sodium citrate와 왕겨 각각 1.5%, K_2HPO_4 0.66%, yeast extract 0.3%, 대두박 0.7%, SDS 0.01% 및 초기 pH를 6.0으로 조절한 배지에서 37℃에서 배양시 최대 효소 활성은 배양 후 36시간에서 나타났으며 이때 효소 활성은 56.6 U/ml이었다. The effects of culture conditions on the production of amylase expressed by Bacillus subtilis LKS88 with a cloned gene from Streptomyces albus KSM-35 were investigated The production of amylase was increased significantly by using sodium citrate and rice hull as a carbon source. In addition, the use of a mixture of sodium citrate and rice hull(1:1) resulted in increase of enzyme production by 20-fold when compared to that of soluble starch. The soybean meal as the nitrogen source could be partially replaced with yeast extract without changing the enzyme production yield. The amylase production was also increased by adjusting initial pH to 6.0 or by adding 0.01% SDS. Maximum amylase production was observed in the medium containing 1.5% sodium citrate, 1.5% rice hull, 0.7% soybean meal, 0.3% yeast extract, 0.66% K_2HPO_4, 0.05% MgSO_4·7H_2O, 0.08% CaCl_2·2H_2O, 0.01% SDS with initial pH of 6.0. The maximum yield of amylase reached 56.6 U/ml when B. subtilis LKS88(pASA 240) was cultured at 37℃ for 36 hr.

糞尿의 好氣性消化에 關한 實驗的 硏究(2)

최정우,엄원택 嶺南大學校 工業技術硏究所 1983 연구보고 Vol.11 No.1

This study is aimed at experimentally determine the process through which the digestion tank reaches normal state and its efficiency thereafter at variable detention and lapse times in treating night soil by the aerobic digestion method. Experiments are run indoor. Samples are loaded in batches and digested for 5,10,15,20 and 25 days in the tank which is continuously aerated at constant temperature, air flow and return sludge rate. The following results are noted: 1. Digestion tank reaches normal state after 9, 8.6, 5.5, 2.4 and 1.9 cycles of operation for the detention time of 5,10,15,20 and 25 days, respectively, the longer the detention time the smaller the number of cycles. 2. Protozoa which primarily occur in the aerobic digestion process somewhat differ from those observed in the activated sludge process, Oikomonas being the prevalent species in the former. 3. Waste sludge stands at 6,5 and 7% when the sample is digested for 15,20 and 25 days, respectively, which indicates reduced cost of sludge treatment. 4. Treatment efficiency of better than 99% is attained in the removal of BOD regardless of the length of digestion time when BOD is loaded at the rate of 1.7Kg/m³.day and 0.7kg/SSkgㆍday 5. Treatment efficiency of better than 95% is attained in the removal of COD(cr) regardless of the length of digestion time when COD(cr) is loaded at the rate 4.0kg/m³.day and 0.4kg/SSkgㆍday 6. Over 94% of NH₄-N is removed by the aerobic digestion process when the sample is digested for 10 to 25 days, and as much of PO₄-³ removed when digested for 10 and 15 days. 7. The optimum digestion time is 15 days, which may be reduced to 10 days.

자바 가상 기계를 목적으로 하는 C컴파일러 설계

최원호,정민수,김도우 경남대학교 정보통신연구소 1999 연구논문집 Vol.1 No.-

요즘 각광 받고 있는 정보통신 분야에서는 무선 네트워킹, 홈 네트워킹, 오피스 네트워킹 등 특정한 플랫폼과 네트웍 디바이스에 상관없이 서로 정보를 주고 받고 있다. 그리고 일반 가정에서도 쉽게 디지털 TV나 휴대폰 등에서 인터넷에 접속하여 정보를 얻을 수 있다. 이런 서로 다른 이기종 플랫폼에 영향을 받지 않고 사용할 수 있는 것이 바로 자바이다. 본 논문에서는 자바만이 가지는 플랫폼 독립적인 특성을 C언어와 같은 고급 언어에 적용해 보고자 한다. 이를 통해서 기존 C언어로 작성된 소프트웨어를 본 논문에서 설계한 컴파일러를 통해 소프트웨어의 재사용성을 높이면서 자바만의 특성을 가지게 할 수 있다. 즉, C언어로 작성된 원시 코드(Source code)를 컴파일러를 이용해서 자바 가상 기계가 인식할 수 있는 목적 코드인 바이트 코드(Byte code)로 변환하고 이를 자바 가상 기계(Java Virtual Machine)가 탑재되어 있는 어떠한 플랫폼에서도 수행할 수 있도록 하는 것이다. 따라서, 본 논문에서는 C언어로 작성된 응용 프로그램을 이기종 플랫폼 상에서 실행 가능 하도록 바이트 코드를 생성하는 컴파일러를 설계한다. The platform independence is the hot issues in the world information and communications, such as wireless networking, Home networking, Office networking. Java is an solution of platform independence. In this paper, we apply the platform independence features of Java to high level language, such as C. In other words, we design a compiler that reads C code and produce bytecodes. Hence, the software written C can be translated into bytecode and can be executed under Java virtual machine.

무선랜용 Q-대역 0.25㎛ pHEMT MMIC 저잡음증폭기 설계

최우성,이원조,권태운,최재하 울산대학교 2002 공학연구논문집 Vol.33 No.1

본 논문에서는 무선랜용 수신 시스템의 첫 단에 쓰이는 Q-대역 2단 MMIC 저잡음 증폭기를 설계하였다. 설계된 증폭기의 이득은 10.312±0.5㏈, 잡음지수는 2.677㏈이다. 입력 정재파비 VSWR_in = 1.072이고, 출력 정재파비 VSWR_out = 1.055이며, 1㏈ 이득압축점은 5.824㏈m IIP9는 13㏈m이다. 이번 저잡음 증폭기 설계에 사용된 pHEMT는 HP-EEsof사의 각각 0.25㎛×50㎛ 크기의 2-finger 루트모델이다. 제작을 위한 레이아웃은 칩사이즈가 1,800×1,500㎛이다 칩사이즈를 고려해서 바이어스딘의 λ/4 라인은 구부려서 구성하였으며 1단과 2단은 50Ω 정합을 하였다. In this paper, the design of Q-band 0.25㎛ pHEMT MMIC 2-Stage Low Noise Amplifier for Wireless LAN is discussed. The LNA has a gain of 10.312±0.5㏈ and a noise figure of 2.677㏈. An input VSWR of the LNA is 1.072 and an output VSWR of the LNA is 1.055. 1㏈ gain compression point of the LNA is 5.824㏈m and IIP of the LNA is 13㏈m. In this paper, HP EEsof's pHEMT 2-finger ROOT Model of 0.25㎛×50㎛ is used. The layout chip size for manufacturing is 1,800㎛×1,500㎛. To reduce the size, a curved shape is adapted for λ/4-line realization. The first and second stage are matched to 50Ω.

FIB를 이용한 나노가공공정 기술 개발

최헌종,강은구,이석우,홍원표 한국공작기계학회 2004 한국공작기계학회 춘계학술대회논문집 Vol.2004 No.-

The application of focused ion beam (FIB) technology in micro/nano machining has become increasingly popular. Its use in micro/nano machining has advantages over contemporary photolithography or other micro/nano machining technologies, such as small feature resolution, the ability to process without masks and being accommodating for a variety of materials and geometries. This paper presents that the recent development and our research goals in FIB nano machining technology are given. The emphasis will be on direct milling, or chemical vapor deposition techniques (CVD), and this can distinguish the FIB technology from the contemporary photolithography process and provide a vital alternative to it. After an introduction to the technology and its FIB principles, the recent developments in using milling or deposition techniques for making various high-quality devices and high-precision components at the micro/nano meter scale are examined and discussed. Finally, conclusions are presented to summarize the recent work and to suggest the areas for improving the FIB milling technology and for studying our future research.