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.

장애인을 위한 도서관봉사에 관한 연구 : 시각장애자를 중심으로

정춘화 동의대학교 2004 인간과 문화 연구 Vol.- No.9

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.

목회화 설교 발전의 고백서

소화춘 목원대학교 신학연구소 1998 신학과 현장 Vol.8 No.-

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.

중학생의 성교육 요구

박춘화,박금자 고신대학교 전인간호과학연구소 2002 전인간호과학연구 학술모음집 Vol.- No.-

The purpose of this study was to identify the need for sex education in middle school students Research subjects were 194 students who attended at I seminary in B city. The period of data collection was from July to August, 2001. Research instrument was composed of 61 structured items : 17 items related to demographics and sex, 44 items related to the need of sex education. Data were collected through the self-report method by the researcher and one trained assistant. The instrument developed by the researchers was employed to measure the need of sex education and it's Cronbach's α = 0.9349 in this research. Data were analyzed by frequency, percentage, factor analysis and t-test using SPSS WIN Program. The findings of this study are summarized as follows : 1. The highest score among characteristics of sex was less interest about sex(42.6%)', 39.0% of subjects got information about sex from friends or elders. 52.3% of subjects consulted friends or elders about sex problems. The number of sex education lessons was 1-2 times in school during last sernester(61.0%). Education by the school nurse was 35.9% to students. 43.1% of subjects announced moderate satisfaction on sex education. 2. The mean score of the need for sex education was 2.88±0.47(lowest value , highest 4). The most wanted sex education factor was 'chastity and sexual responsibility (3.33±0.67)' and followed by 'family and marriage(3.26±.62)' and 'considerations of sex(3.07±0.69)'. Meanwhile, the lowest wanted sex education factor is 'physiological characteristics of male(2.47±0.72)', followed by 'sexual behavior(2.49±0.75)'. The most wanted sex education item was 'the meaning of family(3.54±0.75)' and followed by 'the cautions to prevention from sexual abuse(3.49±0.78)' and sexual activity and responsibility(3.43±0.77)'. Meanwhile, the lowest wanted sex education item is 'masturbation(2.16±0.97)', followed by 'circumcision(2.32±0.97)'. 3. There is no significant difference between boys and girls in mean score about the need for sex education(t=- .715, p= .476). Sex education factor that girl-students wanted was 'physiological caracteristics of female'. Sex education factor that boy-students wanted was 'family and marriage'. Sex education items that girl-students wanted were 'cautions during menstruation', 'the relation of ovulation and pregnancy', 'caution to prevention from sexual abuse' and 'sexual behavior and responsibility'. Sex education items that boy-students wanted were 'the meaning of family', 'the importance of marriage', 'male's sex organs', 'a wet dream', 'the method to resolve sexual curiosity', 'sexual intercourse' and 'the connection with the other sex'. In conclusion, the mean score of the need for sex education is medium. The route to attain knowledge about sex and sexual problem is through consulting friends and elders. Therefore, it is necessary to give sex education that is suitable to the subject's needs and methods. Also, it is necessary to give differently strong point about sex education between female and male students.

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.

유한요소법에 의한 호안의 강제치환 형상에 관한 변형예측 및 현장계측

박춘식,장정욱,하주화 국립7개대학공동논문집간행위원회 2005 공업기술연구 Vol.5 No.-

This study used the finite element method analysis to estimate enforced replacement shapes and replacement depth. The data were expected to be used as the fundamental data of the design through the comparison with the results of the elastic wave exploration and investigation. The results of the research are summarized in the following. (1) After dividing the breakwater into 5models, on which elastic wave exploration was performed, the enforced replacement shape has been obtained by the finite element method. The result was satisfactory compared to the results of the elastic wave exploration. (2) The enforced replacement shapes of the breakwater were compared in different ways; in the design, in the elastic wave exploration in field and in this study. While the enforced replacement shape in the design is substantially different from that in elastic wave exploration in field, it turned out to be similar to the results of this research. (3)If an enforced replacement shape is standardized in configuration of breakwater, depth of soft soil and th value of soil property, it can be used as the standardized section in designing breakwaters.

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.

독서요법에 관한 연구

정춘화 동의대학교 2005 인간과 문화 연구 Vol.- No.10