직렬 리액터를 이용한 계통연계형 태양광 발전 시스템

金大均,鄭春炳,全基英,李丞煥,吳鳳煥,李勳九,金容珠,韓慶熙 명지대학교 산업기술연구소 2005 産業技術硏究所論文集 Vol.24 No.-

Since the residential load is an AC load and the output of solar cell is a DC power, the photovoltaic system needs the DC/AC converter to utilize solar cell. In case of driving to interact with utility line, in order to operate at unity power factor, converter must provide the sinusoidal wave current and voltage with same phase of utility line. Since output of solar cell is greatly fluctuated by insolation, it is necessary that the operation of solar cell output in the range of the vicinity of maximum power point. In this paper, DC/AC converter is three phase PWM converter with smoothing reactor. And then, feedforward control used to obtain a superior characteristic for current control and digital PLL circuit used to detect the phase of utility line.

2.1GHz 대역의 저잡음 증폭기 설계

정태훈,한대현,최영식 東義大學校産業技術開發硏究所 2003 産業技術硏究誌 Vol.17 No.-

본 논문에서는 IMT-2000 기지국(중계기)용 저잡음 증폭기에 적합한 저 전압, 저 전류 동작점을 설정하고 이와 동시에 낮은 잡음 특성과 높은 입력 인터셉트점을 가지는 증폭기를 설계하였다. 입력 부정합에 의한 높은 입력 IP_3를 얻기 위하여 50Ω에 가까운 최적의 잡음지수를 얻기 위한 반사계수 값이 아닌 0.3㏈ 이하의 일정 잡음지수원 상에서 보다 적절한 부정합을 얻을 수 있는 입력 반사계수를 설정하고 출력을 복소 정합회로로 설계하여 두 특성을 최대로 얻을 수 있게 하였다. 본 논문에서는 최근 통신소자로 각광받고 있는 HEMT소자를 사용하였으며 Agilent사의 pHEMT ATF-36077을 능동소자로 채택하고 Agilent사의 고주파 시뮬레이터인 ADS를 이용하여 회로 설계 및 모의실험, 회로 및 성능의 최적화를 수행 하였으며 모의실험 결과를 활용하여 유전율 ε_r=3.0, 두께 0.762㎜인 테프론(Teflon) 기판을 이용하여 제작하였다. 구현한 저잡음 증폭기는 정합 및 바이어스의 최적화를 수행하여 기지국(중계기)용으로 제작되었으며 V_(ds)=2[V], I_d=9[mA]의 동작특성과 낮은 잡음특성, 높은 입력 인터셉트점, 그리고 입/출력에서 양호한 정합 특성을 얻을 수 있었다.

PWM 인버터에서 선형영역 확장을 위한 새로운 과변조 기법

김상훈,한대웅 江原大學校 産業技術硏究所 2001 産業技術硏究 Vol.21 No.B

In this paper, a novel overmodulation strategy for PWM inverters to extend linearity region is presented. The proposed strategy uses the concept of space-vector PWM(SVPWM) based on the zero sequence signal(offset voltage) injection principle. So, by modifying the pole voltage simply, the linear control of inverter output voltage over the whole overmodulation range can be achieved easily. The proposed strategy is so simple that its practical implementation is easy. The validity of the proposed strategy is confirmed by the experimental results.

RC 프레임면내 조적채움벽의 내진성능 평가에 관한 실험적 연구

이정한,차승렬,강대언,오상훈,이용재,이원호,김상대 대한건축학회 2004 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.24 No.1(구조계)

The objectives of this study are 1) to find out the shear behavior and shear capacity of RC bare frames, brick-infilled RC frames, 2) to evaluate the equation of the shear capacity of two types of RC frames by comparison the Japanese Standard and modified equation adopting the test results. The main variable is the absence of brick infill wall. The test results show that the shear capacity of specimen IF-4.2 is 2.3 times as high as that of the specimen IF-4.2.The shear behavior of RC bare frame which is governed by predominant flexural yielding is changed to predominant shear yielding by affection of the brick infill wall. A comparison of the results obtained by the Japanese Standard equation and the modified equation to the test data indicates that the proposed equation is compatible with the test results.

한국성인 정상교합자의 치아크기와 비율에 관한 연구

김대식,김영준,최재훈,한종훈 대한치과교정학회 2001 대한치과교정학회지 Vol.31 No.5

대한치과교정학회 부정교합백서 발간위원회에서 보관중인 한국성인 정상교합자의 표본(남 : 22명, 여 : 55)과 연세대학교 치과대학 교정과에서 부정교합 백서발간을 위하여 수집한 표본(남자 : 21명)을 이용한 한국성인 정상교합자의 치아크기의 계측과 비율에 관한 연구를 통해, 한국성인 정상교합자의 치아크기의 평균치를 구하고, 조화로운 교합관계와 심미성의 획득에 기여하는 치아크기의 비율을 구하여 다음과 같은 결론을 얻었다. 1.한국성인 정상교합자의 남녀 치아크기의 평균치를 구하였다. 2.남녀간 치아크기의 평균치 비교에서 상하악 제1대구치를 제외한 치아에서 총계적으로 유의하게 남자의 치아크기가 여자의 치아크기에 비하여 크게 계측되었다(p<0.05) 3.계측된 한국성인 정상교합자의 치아크기 평균치를 바탕으로 교정치료시 전치부에서의 적절한 수직피개도와 수평피개도, 구치부에서의 적절한 교합관계를 예측할 수 있게 해주는 치아비율을 산출하였다. 1) Sum of incisors = 4 : 2.97 2) Neff의 anterior coefficient = 1.28 3) Bolton의 anterior ratio = 78.29%, overall ratio = 91.14% 4.혼합치열기에서 맹출된 4전치 폭경의 합과 강하악 편측 미맹출 견치와 소구치 폭겸의 합과의 상관관계를 조사한 결과 양의 상관관계를 나타내었으며, 이 상관관계에 의해 상하악 편측 미맹출 소구치 폭경의 합을 예측할 수 있는 회귀방정식을 구하였다. 1) 미맹출 편측 상악 견치와 소구치 폭경의 합 예측 회귀방정식 =10.435018+0.513346×(하악 4전치의 합) 2) 미맹출 편측 하악 견치와 소구치 폭경의 합 예측 회귀방정식 = 9.654002+0.502565×(하악 4전치의 합) The purpose of this study was to measure the average tooth size of Korean with normal occlusion. According to the study, the average tooth ratios between the upper and lower teeth which could assure the proper ovebite, overjet and good interdigitation ware calculated. The normal occluson sample of this study consisted of 43 Korean male adults and 51 Korean female adults. Among them, 22 Korean male adults and 51 Korean female adults were from KAO(Korean Association of Orthodontists), 21 Korean male adults were from Department of Orthodontics, College of Dentistry, Yonsei University. The results from this study were as follows : 1.The average tooth size of Korean Norm classified by male and female was measured. 2.The average tooth size of Korean male adults with normal occlusion was significantly larger than that of Korean female adults except upper and lower first molars.(p<0.05) 3.The tooth ratio which could predict the proper overbite and overjet in anterior teeth and proper occlusion in posterior teeth was calculated. 1) Sum of inciosrs = 4 : 2.97 2) Neff's anterior coefficient = 1.22 3) Bolton's anterior ratio = 78.29%, overall ratio = 91.14% 4.A positive correlation was observed between the sum of lower anterior incisors and the sum of unilateral canine and premolars in each jaw. Based this correlation, the regression equation was made which could predict the sum of unerupted unilateral canine and premolars in mixed dentition, 1) Sum of unilateral unerupted upper canine and premolars' width = 10.435018+0.513346×(sum of lower 4 incisors' width) 2) Sum of unilateral unerupted lower canine and premolars' width = 9.654002+0.502565×(sum of lower 4 incisors' width)

음낭외상시 고환파열에 대한 초음파 검사의 진단적 유용성

김경영,한동준,신대은,노준,문형윤,임동훈,김철성,박성운 朝鮮大學校 附設 醫學硏究所 2007 The Medical Journal of Chosun University Vol.32 No.3

Purpose: We determined the use of scrotal ultrasonography in the initial diagnosis and management of testicular injuries due to blunt scrotal trauma. Mateiials and Methods: We reviewed 54 patients of scrotal trauma in the last 8 years. Forty patients were evaluated by ultrasonography preoperatively. A heterogeneous echo pattern of the testicular parenchyma with loss of oval shape, contour definition was the basis for diagnosis of testicular rupture. Among them, 33 cases underwent scrotal exploration and 7 cases were managed conservatively. The remaining 14 patients were evaluated only by physical examination, 8 patients of them were explored immediately because of suspicious testicular mpture. The accuracy of ultrasonography were determined by comparing radiographic interpretations with intraoperative findings. Results: Among the 33 patients who were evaluated by ultrasonography and explored immediately, there were 26 suspected testicular ruptures on ultrasonography. Surgical exploration revealed testicular rupture in 23 and simple hematoma in 10. The testicular rupture was correctly diagnosed by ultrasonography in the 22 cases, and there were 4 false-positive and 1 false-negative diagnoses of testicular rupture. The sensivity and specificity for the diagnosis of testicular rupture are 96% and 60%, and the positive and negative predictive values are 85% and 86%, respectively, Conclusions: Scrotal ultrasonography, with the main radiographic finding of a heterogeneous echo pattern of the testicular parenchyma with loss of oval shape, contour definition, is highly sensitive on the diagnosis of testicular rupture. And it increases the salvage rate for testicular rupture with preservation of the testicular function and prevents delayed complications of chronic pain, atrophy and orchiectomy associated with missed testicular rupture.

고혈압 환자에서 Leukoaraiosis 정도와 망막증과의 연관성 : 예비연구 Preliminary Results

신동익,한현정,서대희,이광훈 關東大學校 醫科大學 醫科學硏究所 2002 關東醫大學術誌 Vol.6 No.1

Changes in the cerebral white matter (leukoaraiosis;LA) are detected with increasing frequency by computed tomography (CT) and magnetic resonance imaging (MRI) in elderly patients with diabetes mellitus and hypertension. The purpose of this study is to determine whether the severity of retinopathy is correlated with degree of LA in patients with hypertension. Twenty-three consecutive patients with patients with hypertension admitted in the department of neurology were evaluated for degree of LA and severity of retinopathy. 8patients were 15female. The age distribution was between 52 and 85 years(mean 69.1years). The duration of hypertension was between 1 and 30 years(mean8.2 years). The degree of LA was correlated with severity of hypertensive retinopathy(p<0.05), especially in relatively young patient, short periods of disease, and female paitents(p<0.05). We can make a rough estimation of degree of LA with fundus examination without CT or MRI evaluations in hypertensive patients, especially in relatively young and female patients with short durations of disease. However, more broad study should be made for these value and relationship.

가족성 고콜레스테롤혈증 유병자에서 HMG Co-A Reductasen Inhibitor 및 Bile Acid Resin의 투여로 인한 아킬레스건 황색종의 감소

채인호,한기훈,박영배,조주희,김효수,손대원,김철호,오병희,이명묵,최윤식,서정돈,이영우 대한순환기학회 1997 Korean Circulation Journal Vol.27 No.9

강재 슬릿형 댐퍼를 부착한 철근콘크리트조 골조의 거동

신종익,이정한,송한범,강대언,오상훈,차승렬,이용재,김상대,이원호 대한건축학회 2004 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.24 No.1(구조계)

This study investigates the performance of the reinforced concrete frame with the steel plate slit damper. The test was carried out to investigate the structural behavior between the reinforced concrete bare frame and the reinforced concrete frame with the steel plate slit damper. The test results showed that the energy absorption capacity of the damped-frame was several times larger than that of the bare frame. For the damage by the input energy is concentrated on the steel plate slit damper, the ductilities of the former structure were increased and the damaged frame can be reused after exchange the steel plate slit damper.

유세포 측정을 통한 CD34^(+)세포의 정량방법 비교

양형모,서영훈,엄현석,민창기,김희제,정대철,이종욱,진종율,한치화,김춘추,김학주 대한조혈모세포이식학회 1998 대한조혈모세포이식학회지 Vol.3 No.2

본 연구소에서는 현재 CD34^(+) 세포의 정량에 사용되고 있는 4가지 서로 다른 방법을 가지고 골수에 적용하여 그 결과를 비교하였다. 각각의 방법들이 편리한 점과 불리한 점들을 가지고 있었지만, 통계적으로는 유의한 차이를 보이지 않았다. 1) CD34-PE/CD45-FITC 방법13(ISHAGE: International Society of Hematotherapy and Graft Engineering), 2) CD34-PE/CD14-FITC 방법, 3) CD34-PE/CD14-FITC/CD45-PerCP 방법, 4) DNA dye/CD34-PE/CD45-PerCP4(Becton Dickinson) 등을 비교하였으며 그 결과 CD34^(+) 세포의 농도는 다음과 같았다. 1) 0.473±0.345, (%Mean±SD, N=70) 2) 0.663±0.519, (N=20), 3) 0.543±0.381 (N=46), 4) 0.624±0.341, (N=32). 시료로는 여의도 성모병원 카톨릭 조혈모세포이식 센터에서 채혈한 골수를 이용하였다. Four different methods for flow cytometric quantitation of CD34+ cell were compared using bone marrow samples (n=168). Following combination of antibodies were used for the analysis : A) CD45-FITC/CD34-PE (n=70), B) CD14-FITC/CD34-PE (n=20), C) CD14-FITC /CD34-PE /CD45-PerCP(n=46), D) DNA dye/CD34-PE/CD45-PerCP (n=32). Each method showed no significant differences among them (P=0.126, ANOVA test, SPSS Version 7.5). When we compare these methods using same samples (n=12), the P value became 0.832. The mean % of CD34+ cells calculated in this experiment were A) 0.474%, B) 0.663%, C) 0.548%, D) 0.624% respectively. In our laboratory, we decided to use CD45-FITC/CD34-PE methods as a routine protocol.