• 한국정보통신학회논문지
• /
• 제13권10호
• /
• pp.2052-2058
• /
• 2009

디지털 시스템의 동작주파수가 증가하고 전압스윙폭이 감소함에 따라 PCB보드의 정확하고 빠른 해석이 중요하게 되었다. 단위 기둥 행열의 다중곱을 이용하는 전송선로 행열을 이용한 방법은 PCB보드 해석에 있어서 가장 빠른 방법이다. 본 논문에서 PCB보드 임피던스를 계산하는 새로운 방법이 제안되었다. 우선, 이 방법에서 PCB의 단위기둥에 대한 전송선로행열의 고유치와 고유벡터가 계산되고, 단위기둥에 대한 전송선로 행열은 행열요소의 곱셈횟수를 줄이기 위해 행열유사변환을 통해 변환된다. 이러한 유사변환을 방법은 기존방법에 비해 계산시간을 대폭 줄여 줄 수 있다. 제안된 방법은 가로 1.3인치 세로 1.9인치의 PCB기판에 적용되었고, 10배 정도의 계산시간저감 효과를 보였다. 제안된 방법은 보드임피던스의 반복적인 계산을 필요로 하는 PCB설계에 응용될 수 있다.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1995년도 하계학술대회 논문집 C
• /
• pp.1281-1283
• /
• 1995

In this paper, we develop a prototype of the Optical SCM transmission module. This module is possible to application to electric facilities for control and measurements. Transmission channel number is two channels, namely, image and digital signal. In the image transmission, modulation method is AM, baseband signal is NTSC video signal and demodulation use PLL. Modulation of digital signal is QPSK, 1.544Mbps and demodulation use PLL. First, we calculate theoretical analysis about RF and Optical link in the transmission. This calculation is well correspond with practical system and transmission experiment is excellent, but this is only two channel model. And now, we plan to multichannel transmission to measure intermodulation, frequency assignments and optimal channel numbers et al.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2003년도 ICCAS
• /
• pp.1474-1479
• /
• 2003

This paper proposes a transmission interval which includes collisions and retransmissions in the IEEE 802.11 DCF. The transmission probability is used for the calculation of collisions and retransmissions in the DCF. Since the noises are considered to analyze the transmission interval, retransmissions by the noises are included in the proposed transmission interval. The proposed transmission interval takes account of the retransmissions by packet errors, and makes it possible to analyze the maximum throughput of the DCF.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2011년도 제42회 하계학술대회
• /
• pp.718-719
• /
• 2011

Lately, the demand for electrical power has been significantly increased. As a result a power transmission system has been improved. On the other hand fault current increased more than past. Superconducting fault current limiter (SFCL) is one of the solutions to limit fault current. However, SFCL's research has not advanced in a power transmission system fully. Therefore, we studied effect of SFCL in a power transmission system. The power distribution system is open-loop circuit, but a power transmission system is closed-loop system. Consequently, Fault current in a power transmission system is larger than fault current in a power distribution system. we exerimented a simple closed-loop power transmission system circuit.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2015년도 제46회 하계학술대회
• /
• pp.420-421
• /
• 2015

Recently construction of new transmission line is getting harder because of social hostility to transmission tower. Howevere, load is converged in metropolitan area and power plants near this area are old and life of generator will end soon. Therefore, power to supply load in this area should be transmitted from east coast area and southern area. For these reasons, securement of transmission capacity without new transmission line construction is important. In this paper, effect of one circuit AC line change to DC transmission at the same transmission tower on the system available transfer capacity is analyzed.

• Journal of Electrical Engineering and Technology
• /
• 제5권4호
• /
• pp.522-529
• /
• 2010

Distance relay plays an important role in the protection of transmission lines. The application of flexible AC transmission systems (FACTS) devices, such as the static synchronous compensator (STATCOM), could affect the performance of the distance relay because of compensation effect. This paper analyzes the application of distance relay on the protection of a transmission line containing STATCOM. New setting principles for different protection zones are proposed based on this analysis. A typical 500 kV transmission system employing STATCOM is modeled using Matlab/Simulink. The impact of STATCOM on distance protection scheme is studied for different fault types, fault locations, and system configurations. Based on simulation results, the performance of distance relay is evaluated. The setting principle can be verified for the transmission line with STATCOM.

• 대한전기학회논문지:전기물성ㆍ응용부문C
• /
• 제49권7호
• /
• pp.406-411
• /
• 2000

This paper presents the results of performance confirmation tests for domestic 20 [Ton] transmission suspension insulators which will be widely utilized in transmission lines. The new test methods such as power arc test, steep-front-of-wave flashover voltage test, and etc. which have been only utilized for the distribution insulators were applied in transmission suspension insulators. The properties of metal and cement used in the 20 [Ton] transmission insulators were also evaluated by the various analysis techniques. Based on the results, we evaluated the performance of the transmission suspension insulators.

• 드라이브 ㆍ 컨트롤
• /
• 제10권2호
• /
• pp.30-36
• /
• 2013

Tractor is a farm vehicle that is designed to provide a high tractive effort at low speed. It is used for versatile agricultural tasks such as hauling a trailer, tillage, mowing and construction work. Most older tractors use a manual transmission. However, as the intensity of work increases, tractors equipped with automatic transmission become popular due to the work convenience. In order to give the operator a large degree of control in field work, 24 gears with automatic 8-speed and manual 3-speed are arranged in transmission. This paper deals with the gear train that is designed for 8-speed automatic transmission by the engagement of multi-disk clutches. The gear ratio for each speed as well as power transmission mechanism is analyzed through velocity analysis. In addition, constraints of mesh gear ratio are derived by investigating the power flow path in velocity diagram for the given 8-speed gear ratio.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1998년도 하계학술대회 논문집 A
• /
• pp.362-364
• /
• 1998

The transmission of information by inductive loop is required for train-safety and fast running. FSK modulation has been used for transmission of information in fast running. Transmission channel between train and ground must be protected from interference of power line. To protect transmission data from noises, the analysis on the transmission line must be performed in advance. In this paper, transmission line is analyzed in view of reflection and time delay in both noise and signal.

• 유공압시스템학회논문집
• /
• 제6권3호
• /
• pp.23-31
• /
• 2009

Counter shaft transmission is a popular automatic transmission power train in construction vehicles such as wheel loader and forklift. The gear train layout of counter shaft transmission is a very basic and important development stage because it affects the most of components design including hydraulic system and shift control algorithm, etc. This paper presents a design methodology for the gear train layout from the analysis of power flow path and clutch hook-up of the existing counter shaft transmission that is adopted in commercialized construction vehicles. Also, independent constraints for the meshed gear ratios are derived in order to realize forward 4-speed and reverse 3-speed gear ratio. The layout design principle proposed here was applied to the new original counter shaft transmission that is underdevelopment.