사각패치안테나의 공진에 미치는 일축성 기판과 유전체 덮개층의 영향에 관한 연구

이화춘 초당대학교 초고속정보화센터 2000 초고속정보화센터논문집 Vol.1 No.-

Complex resonant frequency of on a uniaxial substrate with a superstrate-loaded microstrip structure is investigated. The study is performed by using a full-wave analysis and Galerkin's moment method in solving the integral equation. The sinusoidal function are selected as the basis function, which slow fast numerical convergence. Numerical results for the effects of anisotropy in the substrate, superstrate permittivity and thickness, in the complex resonant frequency of the rectangular microstrip structure, are also presented. Also, It is found that half-power bandwidth are increased due to the positive uniaxial anisotropy and superstrate.

적층구조를 가진 이중공진 마이크로스트립 패치 안테나의 설계

이화춘, 정남채 초당대학교 초고속정보화센터 2001 초고속정보화센터논문집 Vol.2 No.-

동축급전을 가지는 적층구조를 이용하여 차세대 이동통신인 IMT-2000 주파수 대역용 마이크로스트립 안테나를 설계 및 제작하였다. 협소한 대역폭 문제를 해결하고자 이중 공진을 일으키는 적층 구조의 안테나를 설계하였다. 적층구조 특성을 이용하여 협소한 대역폭 문제를 해결하고, 송·수신의 동작대역이 서로 다른 IMT-2000 주파수대역에 맞추기 위해 이중공진의 특성을 이용하였다. 전송라인 모델을 이용하여 아래 패치의 크기를 설계한 다음 시뮬레이터를 이용하여 최대전력 전달을 위해 최적의 급전위치를 찾았으며 상층기판의 유전율 및 두께를 최적화시켰다. 또한 공기층을 삽입하여 제작의 정밀성과 안테나의 효율을 증가시키고자 하였다. 설계한 안테나의 주파수대역은 1.885GHz∼2.025GHz, 2.11GHz∼2.2GHz의 동작대역을 포함하고 230MHz 이상의 대역폭을 가지도록 설계되었고 측정결과는 하향 1.8745GHz, 상향 2.2GHz에서 공진이 발생하였으며 각각 10.2%와 7.8%의 대역폭을 가지는 결과를 얻었다. Stacked square microstrip antenna was designed and manufactured and tested to apply in next generation mobile communication, on IMT-2000 system(up link: 1.885GHz∼2.025GHz, down link: 2.11GHz∼2.2GHz), which has dual-frequency, broadband and high-gain characteristics. To increase bandwidth we presented dual band stacked microstrip patch antenna with one probe feed using a technology that is stacked patches in which a parastitic element is place above a lower patch. Lower patch was designed by transmission line model and impedance matching point is determined by using simulator. Second, We considered variations of return loss by simulator when dielectric constant and thickness in higher dielectric substrate is varied. Third, to settled distance between lower substrate and higher substrate, we placed to air-gap above lower substrate. Therefore we expected that the efficiency of antenna and exactness of manufacture can be improved by this way. Finally we determined parameters of the antenna through above optimization procedure. With the parameters, We manufactured stack square microstrip patch antenna and measured with HP 8510c network analyzer. The pleasured results are as follows: resonant frequency of 1.8745GHz and 2.2GHz, bandwidth of up to 10.2% and 7.8%, gain of 8dB∼10dB.

타워식 자동 공구 교환장치의 성능 평가

이춘만,노영화,박동근 한국공작기계학회 2006 한국공작기계학회 추계학술대회논문집 Vol.2006 No.-

This study is concerned about the development and performance evaluation of a tower type ATC(Automatic Tool Changer). Recently, many studies have been undergoing to reduce working time in field of machine center. Tower type ATC have been developed to reduce the stand-by time by shortening tool exchanging time. The developed system can store more number of tools in small space. In order to evaluate the performance of tower type ATC, feeding speed and noise are measured by a laser interferometer and a noise level meter.

Systemic Lupus Erythematosus를 동반한 Multiple sclerosis

이지현,이기주,윤성호,부귀범,손현화,박유환,정춘해,김진호,정원영 조선대학교 부설 의학연구소 1998 The Medical Journal of Chosun University Vol.23 No.2

Multiple sclerosis and lupus erythematosus are chronic, potentially disabling diseases of unknown cause. It is a rare occasion that the finding of both diseases occurs in one patient. Because both diseases may affect the central nervous system, it may be difficult at times to differentiate symptoms of lupus erythematosus from those of multiple sclerosis. As far as we know, there was no case report of SLE in multilple sclerosis in Korea. We report a case of multiple sclerosis accompanied by SLE.

광소자의 해석을 위한 효율적인 3차원 광전파방법

이화춘 초당대학교 초고속정보화센터 2002 초고속정보화센터논문집 Vol.3 No.-

본 논문에서는 3차원의 연산을 위한 효율적인 3차원 광전파법을 제안하였다. 이는 기존의 2차원 구조에 많이 사용되었던 DuFort-Frankel법을 3차원으로 확장한 것으로서, 이 방법을 이용함으로써 광전파방법에서의 행렬연산의 횟수를 반으로 줄이여, 수치해석에 소요되는 시간을 최대50%이상 감소시킬 수 있었다. 제안된 광전파법은 모드결합이론에 적용되었으며, 매우 정확한 결과를 얻었다. We proposed an efficient Beam Propagation Method(BPM) algorithm for 3-D analysis, which can handle great amount of data on PC efficiently. The new algorithm, which is an expanded version of DuFort-Frankel algorithm for 3-D analysis, can reduce the number of computations for a given BPM analysis. The new algorithm was applied to a rib-type directional coupler to find the same results as those from the coupled mode theory.

師範大學 敎育課程 模型의 開發에 關한 硏究(Ⅰ) : 物理 및 地球科學 敎育課程을 中心으로 With Reference th Physics and Earth Science

李春雨,禹榮均,李華永 공주대학교 사범대학 과학교육연구소 1983 과학교육연구 Vol.15 No.1

One of the major objectives of this study is to arrange the curricula of the rhysics and the earth science course in the teachers college for improving the academic preparation of secondary school science teachers. To accomplish the objectives, the writers have preferentially analyzed the new science curriculum of the middle school and that of the physics and the earth science of the high school, and also the curricula of the physics and the earth science of the teachers college which will be applied in the pilot curriculum of the teachers college. The new science education may be characterized (1) operationally by an anal-ysis of the practician's activities, (2) intellectually by its constructs, (3) method-ologically by the mode of inquiry and procedures for problem solving. Science is the process which makes knowledge and is the interconnected se-ries of concepts and conceptual schemes that have developed as a result of experi-mentation and observations. and are fruitful of further experimentation and obser-vations. The problems set up in the analysis, in detail, are educational objectives, the contents of subject matter, the method of instruction, management of curriculum. The new and tentative curricula of the physics and the earth science in the teachers college is rearranged on the basis of both theoretical foundation and re-sults analyzed. And the new curricula of the physics and the earth science is organized on the basis of 150 credits, and also intensively, systematically, and logically. And the teaching contents of the physics and the earth science education is desirable to consist of higher level and new topics centering around the contents of secondary school science curriculum. And additionally, some of the followings concerned with the implementation of the curricular construction are suggested as the betterment. (1) Now, on-going 140 credits completion essential for the degree of B. A. for the students enrolled at the national teacher's colleges across the nation, should be strongly trengthened up to 150 credits with a view to covering the present bleak in educational achievement for producing more competent secondary school teachers, which can be said fittable for the imminent, prime objective of our teacher's colleges. (2) This study suggests the model of more reasonable curricular construction, and its actual way of implementation, which is based on the supposed 150 cred-its-completion system, which will be a help to the colleges of 140 credits-basis in curricular activities, by adding or rearranging the necessary number of courses for graduation. (3) The system, which the credits for the minor majors can be taken during the period of school vacation in addition to the regular 150 credits is safely said more desirable. Meanwhile, in the actual conducting of the above like-wise curricular activi-ties, it is supposed to be more desirable that both the choice of concerned depart-ments of the physics and the earth science and those regulations of the col-legesconcerned and ministry of education are expected to be justified in accord-ance with each other for more educational fruit-bearing, so, the more active, and long-range study and suggestions for the betterment should be activated hereafter, with no stop, for the development of our scientific education and building up our national strength itself.

Extracellular Proteinase를 생산하는 효모의 분리동정과 효소의 생산

김창화,이태형,유춘발,진익렬 한국미생물생명공학회 ( 구 한국산업미생물학회 ) 1996 한국미생물·생명공학회지 Vol.24 No.4

토양 및 농업용수와 하수 등으로부터 분리한 237주의 효모를 대상으로 단백질 분해력이 있는 효모 13주를 분리한 후, 알카리 조건에서 활성이 우수한 효모 TH65의 형태학적 및 생리생화학적 특성을 조사하고, 그 결과를 Saccharomycopsis lipolytica KCCM 12495 및 S. lipolytica KCCM 35426와 비교한 바, 발효성이 없고 대부분의 당류와 nitrate를 이용하지 못하는 등 대조 균주와 거의 동일한 특성을 보임에 따라 분리균주를 Yarrowia lipolytica TH65로 동정하였다. 분리효모의 protease 생산성을 조사한 결과, 탄소원으로는 glycerol과 glucose가 좋았고, glucose 농도는 0.5%가 적당하였다. 질소원으로는 0.6% skim milk에서 가장 많은 효소가 유도되었고, 아미노산에 의한 영향을 조사한 결과는 cysteine, cystine 및 tryptophane에 의해 효소 생산성이 감소되는 것으로 나타났다. Yeast extract 농도의 영향을 조사한 결과는 0.1~0.5%에서 양호하였으나, 첨가된 대부분의 무기염과 인산염은 효소생산성을 증가시키지 못하는 것으로 나타났다. 배양초기 pH는 9~11에서 가장 좋았고, 배양온도는 18℃에서 가장 좋았으며, 배양시간에 따른 효소생산성은 36시간에서 최고치를 나타내었다. A yeast strain TH65 producing a high level of proteinase under alkaline condition was isolated, and identified as Yarrowia lipolytica by morphological, physiological, and biochemical characteristics. In proteinase productivity, glycerol and glucose among tested carbon sources were very effective, and optimum concentration of glucose was 0.5%. Skim milk was found to be most effective nitrogen source in productivity, and its optimum concentration was 0.6%. But, cysteine, cystine and tryptophane decreased the proteinase productivity. Yeast extract was relatively effective at the range of 0.1~0.5%. The yeast showed maximum production of proteinase at 18℃, pH 9~11, and cultivation time of 36 hours.

「질트리코모나스」(Trichomonas vaginalis)의 주별(株別) 병원성에 따른 Isozyme 양상에 관한 실험적 연구

劉能和,明春玉,鄭坪林,李根泰 연세대학교 의과대학 1984 연세의대논문집 Vol.17 No.1

兩眠 시각 시스템에서 頭部 및 眠球의 운동 보상법

정남채,이화춘 초당대학교 초고속정보화센터 2002 초고속정보화센터논문집 Vol.3 No.-

본 논문에서는 회전 및 병진의 외란이 가해진 경우 시각 이외의 자율운동 보상법에 관해서 고찰하였다. 양안시에 의한 주시점까지의 시차 및 방향의 측정과 계속적으로 주시하기 위한 VOR의 이득을 쉽게 계산할 수 있었다. 두부의 회전 각속도 및 회전 각도는 gyro 센서에 의해 얻어지더라도 gyro 센서의 값은 화상정보와는 무관하며, 대단히 짧은 시간내(약 1 ms)에 데이터를 샘플링할 수 있기 때문에, VOR의 이득을 1로 하여 남은 오차를 보간함으로써 화상정보를 보다 쉽게 주시할 수 있었다. When external noise of rotation and lateral are imposed to binocular vision system, self-regulation moving compensation method except sight is examined in this treatise. We could measure both binocular disparity and direction by binocular vision until visual point and calculate easily VOR's gains to stare continuously. Even if cephalic rotating angular velocity and rotating angle are obtained by gyro sensor, the value of gyro sensor is unrelated with image information, and we could stare a image information more eisily, deciding VOR's gains by 1 do and modifing the remained error because we can do sampling the data in short time(about 1ms).

젊은 남자에게 발생한 통상성 간질성 폐렴과 동반된 폐암 1예

박종숙,이준혁,박성우,장안수,박춘식,박재성,백상현,고은석,신화균 순천향의학연구소 2004 Journal of Soonchunhyang Medical Science Vol.10 No.2

Usual interstitial pneumonia(UIP) is relatively rare disease of lung parenchyme under the age of 50. Lung cancer is reported to occur as a complication of UIP, but has not been reported in young age patient with UIP in Korea. A 35-year-old man was admitted to the hospital because of dyspnea, cough and mild fever. He had been suffered from dyspnea during 3 years. The dyspnea worsened recent 1 month ago. He had been treated with pneumonia at another hospital during 4 months before this admission. Chest radiographs and High resolution CT showed subpleural and basal dominant reticular opacities in both lung with no change until now. He was smoker and his occupation was car engine-man dealing with benzene. UIP is suspected by history and radiologic findings. Operation for open lung biopsy was performed to obtain lung specimen via video-assisted thoracoscopic surgery. Patient's pathologic examination showed UIP combined with adenocarcinoma in RLL superior segment and posterobasal segment and RLL lobectomy was done. After operation, the patient has been in cancer free condition so far. We report a case of UIP combined with lung cancer in young man with brief review of the literature.