http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
통신위성과 지상차량간의 통신에 있어서 가로수로 인한 신호감쇠
홍의석 光云大學校 1988 論文集 Vol.17 No.-
Using Fresnel diffration theory the atteunuation cased by a model tree was calculated to be near 10dB and the maximum fade was found to increase by the logrithm of the number of branches. The results obtained in this paper can be used to reproduce measured data of scattering and fading and to make a quantitative estimate of the influence of parameters such as elevation angle, the distance of scatterers to the mobile and the frequency of tree shadowing.
전기석,홍의석 光云大學校 1976 論文集 Vol.5 No.-
In the design of low cost television receivers when a well-regulated D.C. supply is desired, the Cost of the power supply becomes a major expense. This is especially true when D.C Voltages desired are around 100 Volts and Current require ments exceed 5 amperes. An inexpensive line connected system is described blow which uses an S.C.R. in series with the 120 Volts, 60Hz A.C. line. This system is ideally suited to provide about 50 to 120 Volts D.C. at Currents up to about 0.75 amps. This supply will provide high performance at low cost. Its gain and stability can be tailored to the specific application. All the solid-state components are enough to fit on a small module. It can be an inexpensive, efficient power supply system.
An Analysis of Rectangular Microstrip Resonator
Hong, Ui-Seok 대한전자공학회 1987 전자공학회논문지 Vol. No.
In calculating resonant frequencies of a microstrip resonator the effect of the stray field at resonator edges has been neglected in most publications. The formula for resonant frequencies therefore provided inaccurate results. In the paper the effective dimension and the dynamic dielectic constant of a resonator are defined and obtained for more accurate resonant frequencies and qualty factor by including the effect of stray fields. Theoretical results obtained from the new formula show good agreement with experimental results. In addition, the effect on resonant modes of the distance and coupling angle between the microstrip line and the resonator is also observed.
홍의석(Ui Seok Hong),정소라(So La Jung),장호(Ho Jang),김성진(Seong Jin Kim) 한국트라이볼로지학회 2007 한국트라이볼로지학회 학술대회 Vol.2007 No.11
Tribological properties of phenolic resins in the friction materials for C-SiC brake systems were investigated. Boron-phosphorus modified resin, silicon modified resin, and straight resin were used as binders of friction materials. A simple formulation containing aramid pulp, potassium titanate, zircon silicate, and phenolic resin was used to investigate the effect of the resins at elevated temperatures up to 400℃. Friction stability and wear rate of the three friction materials were compared as a function of temperature and the activation energy for the wear rate of the three phenolic resins were obtained from Arrhenius type plot. It was found that the composite materials clearly exhibit different wear mechanisms below and above the critical temperatures. The friction materials with B-P modified resin showed good wear resistance and friction stability compared with the others.