• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2002년도 제4회 영호남학술대회 논문집
• /
• pp.37-40
• /
• 2002

Ground connection began by experimenting lightning with the use of a kite and it means electric appliances, communication equipments, measuring instruments and so on connecting the Earth in order to flow away overcharged electricity. There are two kinds of earth connection: Power Ground and Signal Ground. Power Ground is for preventing an electric shock and in general there's no current in the connector. However in an accident, there's a quick flow of electricity out to the Earth. Signal Ground is not only for the safety of appliances but also for the safety of equipment operation. This paper is about connection for noise and interference reduce in order to prevent wrong operation and distortion of signal in the electrical appliances which can take place in cable TV.

• 자원환경지질
• /
• 제31권1호
• /
• pp.53-57
• /
• 1998

Transient electromagnetic (TEM) method is also affected by cultural and natural electromagnetic (EM) noises, since it uses part of the broadband ($10^{-2}$ to $10^5Hz$) spectrum. Especially, predominant EM noise which affects a moving transmitter-receiver TEM system is sensor motion-induced noise. This noise is caused by the sensor motion in the earth magnetic field. The technique for reducing the sensor motion-induced EM noise presented in this paper is based on Halverson stacking. This Halverson stacking is generally used in a time-domain induced polarisation (IP) system to reject DC offset and linear drift. According to spectrum analysis of the vertical component of sensor motion-induced noise, the frequency range affected by the motion of an EM sensor is less than about 700 Hz in this study. With the decrease of the frequency, the spectral power caused by the motion of a sensor increases. For example, at the frequency of 200 Hz, the spectral power of the sensor motion-induced noise is $-90dBVrms^2$ while the spectral power of the EM noise measured with a fixed sensor on the ground is $-105dBVrms^2$, and at the frequency of 100 Hz, the spectral power of the sensor motion-induced noise is $-70dBVrms^2$ while the spectral power of the EM noise measured with a fixed sensor on the ground is $-105dBVrms^2$. With applying Halverson stacking to an artificial noise transient generated by adding a noise-free transient to sensor motion-induced noise measured without pulsing, it is shown that the filtered transient is nearly consistent with the noise-free transient within a delay time of $0.5{{\mu}sec}$. The inversion obtained from this filtered transient is in accord with the true model with an error of 5%.

• 대한원격탐사학회:학술대회논문집
• /
• 대한원격탐사학회 2002년도 Proceedings of International Symposium on Remote Sensing
• /
• pp.202-207
• /
• 2002

EOC (Electro-Optical Camera) of KOMPSAT-1 (Korea Multi-Purpose SATellite) has been producing land imageries of the world since January 2000. After image data are acquired by EOC, they are transmitted from satellite to ground via X-band RF signal. Then, EOC image data are generated and pass through radiometric and geometric corrections to generate standard products of EOC images. After radiometric correction on EOC image data, Modulation Transfer Function (MTF) compensation is applicable on EOC images with user's request for better image quality. MTF compensation is concerned with filtering EOC images to minimize the effect of degradations. For Image Receiving and Processing System (IRPE) at KOMPSAT Ground Station (KGS), Wiener filter is used in MTF compensation for EOC images. If the Pointing Spread Function (PSF) of EOC system is known, signal-to-noise power spectra ratio is the only factor in the determination of Wiener filter. In this paper, MTF compensation in IRPE at KGS is introduced and MTF compensated EOC 1R images are generated using Wiener filters with various signal-to-noise power spectra ratios. MTF compensated EOC 1R images are correlated with EOC 1R images for observing linearities between them. As a result, the effect of signal-to-noise power spectra ratio is shown on MTF compensated EOC 1R images.

• 소음진동
• /
• 제7권4호
• /
• pp.621-629
• /
• 1997

For computer aided design and costruction of low noisy power plants, indoor and outdoor noise prediction program has been developed. The program utilizes the predefined data of noise sources and building materials and has the faculty to estimate the source level using the empirical formula in case of the measured data not being available. In the noise prediction, the mutual noise propagation between indoor and outdoor sites are considered. The outdoor noise source in the calculation of geometric divergence effects is modelled as the omni-directional finite line or planar source according to the source geometry and the receiving points. Outdoor noise prediction is carried out to consider the diffraction effect due to plant structures as well as the attenuation effect due to atmospheric absorption and soft ground. The results of indoor and outdoor noise prediction for a recently constructed diesel engine power plant show good agreement with the measured.

• 한국정보통신설비학회:학술대회논문집
• /
• 한국정보통신설비학회 2007년도 학술대회
• /
• pp.215-218
• /
• 2007

In this paper, we have analyzed the effects from the change of separation distance between grounding equipment at end of telecommunication line and the inducting facilities in power inducting situation. In the result of measurement, we can see that as the separation distance between grounding equipment ant end of telecommunication line and the inducting facility become longer, the induced noise level and PIF level is decreased. From the another experiment results about the effect of changing the impedance size in both ends of telecommunication line, however, we already knew that as the ground impedance at either end of the telecommunication line become grower, the noise level is increased, and as the ground impedance at either end of the telecommunication line become smaller, the noise level is decreased. Hence we can not define the relationship exactly between separation distance from inducting facility to inducted facility and the induced noise level because when the grounding equipment is moved, its impedance size is changed too. In conclusion, changing the separation distance between grounding equipment at end of telecommunication line and the inducting facilities have not influence on the induced noise level.

• 한국전자파학회논문지
• /
• 제21권2호
• /
• pp.170-178
• /
• 2010

논문에서는 전원부에서 노이즈가 발생되어 신호선에 노이즈가 유기될 때, 유전체의 손실 특성이 노이즈에 미치는 영향에 관해서 연구를 하였다. 이를 분석하기 위해 Full-wave 시뮬레이터인 Ansoft사의 HFSS(High Frequency Structure Simulation)와 CST사의 MWS(MicroWave Studio)의 계산 결과와 측정 결과를 비교하여 신뢰성을 확보하였고, 실제 사용되고 있는 4가지의 상용 기판에 대한 유기되는 노이즈를 해석하였다. 또한, TLM(Transmission Line Method)를 이용해서 전원면의 회로 모델 구성 시 기판의 유전체 손실을 반영할 수 있는 Debye 모델을 적용하여 주파수에 대한 임피던스를 분석할 수 있는 모델을 적용 측정 결과와 3 GHz까지 일치하는 모델을 얻었다.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 1997년도 춘계학술대회논문집; 경주코오롱호텔; 22-23 May 1997
• /
• pp.452-459
• /
• 1997

For computer aided design and construction of low noisy power plants, indoor and outdoor noise prediction program has been developed. The program utilizes the predefined data of noise sources and building materials and has the faculty to estimate the source level using the empirical formula in case of the measured data not being available. In the noise prediction, the mutual noise propagation between indoor and outdoor sites are considered. The outdoor noise source in the calculation of geometric divergence effects is modelled as the omni-directional finite line or planar source according to the source geometry and the receiving points. Outdoor noise prediction is carried out to consider the diffraction effect due to plant structures as well as the attenuation effect due to atmospheric absorption and soft ground. The results of indoor and outdoor noise prediction for a recently constructed diesel engine power plant show good agreement with the measured.

• 한국소음진동공학회논문집
• /
• 제26권1호
• /
• pp.49-54
• /
• 2016

The wind power plants were installed in many places because of the low climate changing effects since 2000. Generally, the wind power plants located in the seaside and the mountainous area and the heights of the windmills are about 40 m~140 m above the ground level. So the noises emitted from the wind power plants propagate far away compared with other environment noise sources like trains and cars noise. Because of these reasons, the noise emitted from the wind power plant is easy to cause the additional social problems like as noise complaints. Under the situation, the ministry of environment has established the guideline to evaluate the environmental effects for the wind power plant. According to the guideline, the noise of the wind power plant has to meet 55 dB(A) at daytime and 45 dB(A) at night in the residential area, which is regulated in the noise and vibration management law. But, it is difficult to estimate the noise emitted from the wind power plant because of the absence of the prediction model of the wind power plant noise. Therefore, the noise prediction model for wind power plants using the regression analysis method is developed in this study. For the development of the model, the sound pressure levels of the wind power plants in Jeju island are measured and the correlations between the sound pressure levels are analyzed. Finally, the prediction equation of the wind power plant noise using by regression analysis method derived. The prediction equation for the wind power plant noise proposed in this study can be useful to evaluate the environmental effects in any wind power plant development district.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2001년도 하계종합학술대회 논문집(2)
• /
• pp.129-132
• /
• 2001

This paper presents an efficient method to estimate the maximum SSN (simultaneous switching noise) for ground interconnection networks in CMOS systems using Taylor's series and analyzes the truncation error that has occurred in Taylor's series approximation. We assume that the curve form of noise voltage on ground interconnection networks is linear and derive a polynomial expression to estimate the maximum value of SSN using $\alpha$-power MOS model. The maximum relative error due to the truncation is shown to be under 1.87% through simulations when we approximate the noise expression in the 3rd-order polynomial.

• 대한전기학회논문지:전기물성ㆍ응용부문C
• /
• 제50권3호
• /
• pp.115-119
• /
• 2001

This paper presents an efficient and simple method for analyzine maximum simultaneous switching noise (SSN) on ground interconnection networks in CMOS systems. For the derivation of maximum SSN expression, we use ${\alpha}$-power law MOS model and Taylor's series approximation. The accuracy of the proposed method is verified by comparing the results with those of previous researches and HSPICE simulations under the contemporary process parameters and environmental conditions. The proposed method predicts the maximum SSN values more accurately when compared to existing approaches even in most practical cases such that exist some output drivers not in transition.