마이크로스트립-프로브 급전을 이용한 U형 슬롯 패치 안테나 설계

이승엽 여수대학교 1999 論文集 Vol.14 No.2

A microstrip-probe feed structure for patch antennas with electrically thick air substrate is presented. This new type of feed, microstrip line combined with probe, lies between the patch and the ground. Therefore, this feed has several advantages over a coaxial-probe feed. As confirmed by our experimental measurements, we improved the matching and the front to back ratio(F/B) characteristic over a wide bandwidth. An antenna bandwidth as large as 3 times that of a conventional rectangular microstrip antenna has also been obtained. Details of the proposed design and experimental results are presented.

인터넷 기반의 구조물 계측시스템 연구

김치엽,최만용,권일범,이승석 한국비파괴검사학회 2003 학술대회 논문집 Vol.- No.1

Structural health monitoring system should developed to be based on internet and database technology in order to manage efficiently large structures. This system is operated by internet connected with the side of structures. The monitoring system has some functions: self monitoring, self diagnosis, and self control etc. Self monitoring is the function of sensor fault detection. If some sensors are not normally worked, then this system can detect the fault sensors. Also Self diagnosis function repair the abnormal condition of sensors. And self control is the repair function of the monitoring system. Especially, the monitoring system can identify the replacement of sensors. For further study, the real application test will be performed to check some unconvinrences.

마이크로스트립 선로의 트랜지션을 위한 비아(via) 해석 및 설계

이승엽 여수대학교 산업기술지역개발연구소 2000 産業基術硏究所 論文集 Vol.9 No.-

The miniaturization and ever higher density packing of electronic devices is driving a trend toward three-dimensional, multilayer circuits. At the same time, the clock rates in digital devices and the operating frequencies in communication systems aue steadily increasing. In multiiayer circuits, signals are carried between the layers through via. Therefore, this paper reports the propagation characteristics of a via. Especially, the effects of rod diameter and clearance hole size. are examined. There is a wide range of sizes of via in multilayer circuits, so the sizes of via in this paper were selected for ease anaccuracy of measurements. The obtained results showed that at high frequencies, radiation is at a significant level and the frequency characteristics of radiation depend on the structure of the via

시간 영역에서 결합마이크로스트립 선로의 펄스전송 특성 해석 및 실험

이승엽 여수대학교 2002 論文集 Vol.17 No.-

As circuit dimension of M(M)IC's is smaller due to recent advances in microelectronic technology and clock rates increase, inter line spacing is decresing. Therefore an accurate time domain analysis of pulse propagation in various coupled microstrpline used in M(M)IC's is required. It is required that distortion of coupled microstripline including feeding line(unified coupled line) is needed. In this paper, It is obtained the requirement that the proper strip spacing to consider the effects of even/odd-mode distortion should be chosen. the distortion of coupled microstripline including feeding line(unified coupled line) is needed. In this paper, It is obtained the requirement that the proper strip spacing to consider the effects of even/odd-mode distortion should be chosen. The distortion of a picosecond electrical pulse caused by dispersion and crosstalk as it propagates along coupled pair of microstrip is investigated and measured.

한국판 스미스클라인 비챰의 '삶의 질'척도를 이용한 공황장애 환자의 삶의 질에 관한 연구

이승호,제영묘,김상엽,이대수,최은영 대한생물치료정신의학회 2000 생물치료정신의학 Vol.6 No.1

Objectives : In this study, we researched the change of 'quality of life(QOL)' of patient with panic disorder by KvSBQOL and the predictors affecting the change of 'quality of life'. Methods : 30 outpatient with panic disorder were tested by questionnare for panic disorder and KvSBQOL. Frst, they were classified as when healthy before panic episodes(a point of time 1), when first diagnosed as panic disorder in the psychiatry(a point of time 2), and when treated after diagnosis(a point of time 3). Second, the change of QOL scores in five factors at each point was observed, Third, the correlation between the change of QOL scores(point 3 score-point 2 score) and the several predictors(Onset age, Degree of change in panic symtom, Degree of change in anticipatory anxiety, Degree of change in agraphobia, Spended time to diagnose panic disorder, Duration of treatment) were studied. Results : 1) QOL mean scores of a point of time 1,2 and 3 were 166.267±38.24, 94.367±34.00, 161.367±34.37, respectively. 2) The change of QOL scores in all five factors of KvSBQOL(factor1 Competence, factor2 Psychological well-being, factor3 Stability, factor4 Physical well-being, factor5 Activity)at each point was significant(P<.000). 3) The change of QOL mean scores(point 3 score-point 2 score) have significantly negative correlation with the change of score in anticipatory anxiety but not other predictors. Conclusions : Difference in QOL scores between a point of time 1 and 3 is 4.9, indicating that the psychiatric treatment is important in improvement of QOL, the anticipatory anxiety is an important predictor of QOL(P<.001). and it suggested that diminished anticipatory anxiety is very important to maintain of high QOL in patient with panic disorder.

공초점 표면 증강 라만 분광법을 이용한 금 나노 입자의 시그널 증폭 효과

최승열,이상엽,주재범 한양대학교 이학기술연구소 2003 이학기술연구지 Vol.6 No.-

본 연구에서는 고감도 나노-바이오 프로브로 이용하기위한 25-100nm 크기의 다양한 금나노 입자들을 제조하였다. 제작된 금 나노입자의 크기는 특성적인 UV/Vis 흡수 밴드를 이용하여 확인하였으며, 제조된 25-100 nm 직경 크기의 나노 입자에 10^(-8)M의 라만 활성 염료 (crystal violet)을 흡착시켜 서로 다른 크기의 나노 입자에 흡착된 시료의 라만 시그널 증폭효과를 관측하였다. 그 결고,785nm diode laser를 사용하였을 경우 70 nm 크기의 금 나노입자에대하여 가장 크 시그널 증폭효과가 확인되었다. 또한 시료가 흡착된 금 나노입자를 다시 은 나노 입자로 coating하였을 경우 더 큰 시그널 증폭 효과가 관측되었다. Different sizes of gold nano particles in the 25-100 nrn range were prepared by the citrate reduction method. These gold nano particles have a strong potential to be used as highly sensitive nano-bio probes. The particle size was identified using their characteristic UV/Vis absorption bands. In order to find a size-dependent Raman enhancement effect, 10^(-8) M of crystal violet was adsorbed on different sizes of gold nano particles. Confocal Raman microscopy is used to investigate the optical signal enhancement effect. When 785 nm diode laser was used as an excitation source, the 70 nm size of gold shows the best signal enhancement effect. Furthermore, it shows a better signal enhancement effect when the gold nano particles are coated with silver nano particles.

Full-wave방법을 이용한 CPW 해석

이승엽 여수대학교 2002 論文集 Vol.17 No.-

Analysis of CPW(Coplanar Waveguide) is presented using Full-wave method in the spectral domain. The characteristics of the CPW are numerically calculated by Galerkin's method and compared with ones of microstrip lines. It is shown that the variation of effective dieletric constant versus frequency in CPW line is less dependent than that in microstrip line. It means CPW is more attractive feeder line of antenna in ultra wide band than microstrip line.

가변구조제어를 이용한 대체에너지용 인버터 시스템

朴勝圭,金兌燁,安鎬均 창원대학교 공작기계기술연구센터 1999 연구업적집 Vol.1 No.1

This paper proposes the instantaneous control method, structure and characteristics of inverter system for alternative energy. The variable structure control and adaptive parameter estimation is applied to this system. which realizes following function; ① the synchronization of phase, frequency and amplitude between inverter voltage and utility voltage at stand-alone mode ② the synchronization of phase between inverter current and utility voltage at utility voltage at utility interactive-mode. To reduce chattering problem of variable structure control smooth function is used. The result of simulation and experiment shows the effectiveness of proposed control scheme and equivalent circuit; the good performance, robustness of the proposed control structure. and the reduction of THD in the inverter output.

Langmuir-Blodgett막 MIM소자의 전도 특성

권영수,유승엽 東亞大學校 附設 情報通信硏究所 1997 情報通信硏究所論文誌 Vol.5 No.1

Langmuir-Blodgett (LB) method have been used by many researcher because of its facility to control the thickness of film as molecular order and orientation of molecular. We fabricated MIM device using maleate copolymer LB films(2C??MA-VA-VE₂) and electrical conduction mechanism in ultra-thin LB film were investigated. In our experimental results, the maleate copolymer LB film have the property of insulator like organic ultra-thin film. Its dielectric constant were about 4.0∼6.0 by I-V measurement and frequency-capacitance measurement. Schottky current was appeared as electrical conduction current and Schottky barrier was about 0.9[eV]

금속이온 농도에 의한 IMI-O LB막의 전기전도도 특성

정상범,유승엽,권영수 동아대학교 정보기술연구소 2000 情報通信硏究所論文誌 Vol.8 No.1

Metal ion complex of poly(N- (2-4-imidazolyl)ethyl)maleimide-alt-1-octadecene (IMI-O) polymer used to confirm the possibility of molecular device made by Langmuir-Blodgett(LB) method. Electrical properties of the metal ion complex LB film were investigated using Metal/Insulator/Metal(MIM) structure. In the surface pressure-area(π-A) isotherms of IMI-O polymer, the surface pressure at collapse point has a difference due to the interaction between polymer and metal ions. And the complex between polymer and metal ions could be verified through the investigation by Raman spectroscopy. In the current-voltage(I-V) property, the conductivity change of IMI-O polymer complexes due to the kinds of metal ions couldn't be observed. However, the limiting area of molecules was changed by the concentration of the metal ions and the conductivity was increased with the occupied molecular area.