• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2004년도 하계학술대회 논문집 A
• /
• pp.391-393
• /
• 2004

Transmission line outage is influenced by several weather factors: wind, rain snow, temperature, cloud and humidity. So, in this paper try to see how much each weather factors have effect on the transmission line outage and it is analyzed that which weather variables have close relation with transmission line historical outage data in KEPCO systems. These statistic correlation analysis may provide system operators useful information about system operation and planing.

• 한국정보통신학회논문지
• /
• 제27권1호
• /
• pp.135-138
• /
• 2023

In this paper, we study real-time error in the context of monitoring a binary information source through a delay system. To derive the average real-time error, we model the delay system as a discrete time Geo/D/1/1 queueing model. Using a discrete time three-dimensional Markov chain with finite state space, we analyze the queueing model. We also perform some numerical analysis on various system parameters: state transition probabilities of binary information source; transmission times; and transmission frequencies. When the state changes of the information source are positively correlated and negatively correlated, we investigate the relationship between transmission time and transmission frequency.

• 한국정밀공학회지
• /
• 제14권1호
• /
• pp.90-100
• /
• 1997

Sppur gear trains are used widely in high precision machines because gear trains have an advantage of exact transmission of angular velocity. Especially, gear trains are used in high quali8ty photocopying and photography OA machines. In general, gears have errors in manufacturing and assembling process and the errors are limited by tolerances. As the result, the tolerances cause the performance error. Therfore, it is important to predict transmission error caused by the tolerances for the tolerance design. Earlier tolerance design methods use mainly experimental and geometrical techniques. In this paper, a method for gear train analysis with tolerance is proposed. Because the method uses dynamic contacts, it is possible to consider irregularities and assemble errors of gears. In addition, the method can predit dynamic loads on the teeth of gears.

• 한국정보통신학회논문지
• /
• 제26권2호
• /
• pp.317-320
• /
• 2022

This paper studies real-time error in the context of monitoring a symmetric binary information source over a delay system. To obtain the average real-time error, the delay system is modeled and analyzed as a discrete time Markov chain with a finite state space. Numerical analysis is performed on various system parameters such as state transition probabilities of information source, transmission times, and transmission frequencies. Given state transition probabilities and transmission times, we investigate the relationship between the transmission frequency and the average real-time error. The results can be used to investigate the relationship between real-time errors and age of information.

• 한국전기전자재료학회논문지
• /
• 제23권8호
• /
• pp.645-650
• /
• 2010

The continuous increase demand for electric power leads to the additional construction of transmission facilities, but it is not easy to acquire right-of-way for transmission facilities. Therefor, there is a need for compact tower that can be built on a narrow right-of-way the compact tower with polymer insulation arm is a solution. It can be upgrading conventional 154 kV transmission line voltages to 345 kV levels. However transmission voltage is increasing, environment interference (corona noise, radio interference, etc.) will occur gradually. This environment interference is depending on the electrical clearances of tower and configuration of conductors. Therefore the analysis of the factors of environmental interference is necessary in order to upgrading transmission voltage. This paper presents the design factor of a compact tower to meet the environmental interference standard.

• Journal of Advanced Marine Engineering and Technology
• /
• 제32권6호
• /
• pp.964-973
• /
• 2008

In this study, a short-wavelength coplanar-type transmission line employing periodic ground structure (PGS) was developed for application to miniaturized on-chip passive component on Si Radio Frequency Integrated Circuit (RFIC). The transmission line employing PGS showed shorter wavelength and lower characteristic impedance than conventional coplanar-type transmission line. The wavelength of the transmission line employing PGS structure was 57 % of the conventional coplanar-type transmission line on Si substrate. Using the theoretical analysis. basic characteristics of the transmission line employing PGS (e.g., bandwidth. loss, impedance, and resonance characteristics) were also investigated in order to evaluate its suitability for application to a development of miniaturized passive on-chip components on silicon RFIC. According to the results. the bandwidth of the transmission line employing PGS was more than 895 GHz as long as T is less than 20${\mu}m$, and the resonance characteristic was observed in 1239 GHz, which indicates that the PPGM structure is a promising candidate for application to a development of miniaturized on-chip passive components on Si RFIC.

• 동력기계공학회지
• /
• 제20권5호
• /
• pp.60-65
• /
• 2016

Dynamic performance of transmission has a substantial effect on dynamic performance and fuel efficiency of a vehicles. Dynamic performance of transmission and mass moments of inertia of transmission gears are related directly each other. Then a smaller amount of kinetic energy from vehicles that repeat acceleration and deceleration requires lighter rotating part in transmission. It is going to increases fuel efficiency as a result. In this study, equivalent inertia moments of inertia at different speeds were calculated by simplifying the transmission system. To find out lightening effect at low speed level gear on fuel efficiency, the powerflow of transmission was analyzed. And the lightning effect of the rotating parts in transmission is compared with the mass reduction of sprung parts in vehicle.

• International Journal of Automotive Technology
• /
• 제8권2호
• /
• pp.225-232
• /
• 2007

A tooth profile modification for loaded gears is used to avoid a tooth impact. Since a tooth profile error causes amplification of the cumbersome whine noise in automotive gear transmissions, an optimal quantity of tooth profile modifications must be obtained for good performance in the vibration sense. In this paper, a tooth profile modification curve considering profile manufacturing errors and elastic deformation of the gear tooth is formulated; in addition, transmission errors of the gear system with modified teeth are verified. The equivalent excitation due to transmission errors is formulated. For experimental evaluation of the transmission error, the transmission error for a simple gear system was measured by two rotational laser vibrometers. Finally, we perform a comparative analysis between the calculated and measured responses to the excitations due to the transmission error to verify the practicability of the application to automotive transmissions.

• 조명전기설비학회논문지
• /
• 제28권8호
• /
• pp.40-46
• /
• 2014

The development of the superconducting fault current limiter (SFCL) to apply into a power transmission system where makes larger fault current compared to the power distribution system has been performed. Among various SFCLs, the trigger-type SFCL is suitable for application into the power transmission system due to the effective reduction on power burden of the high temperature superconducting element (HTSC) for the larger fault current. To protect the power transmission line in the power grid, the distance relay, which decides to interrupt fault section where can be calculated by the measured voltage and current from sound grid, is one of important protective devices in the power transmission system. However, the operation of the distance relay from the impedance of the fault point on the transmission line is affected by the impedance of the trigger-type SFCL. Therefore, the analysis on the operational characteristics of distance relay considering the application of the SFCL is required. In this paper, the effect on the operation zones of the distance relay by the impedance of the SFCL in a power transmission system was analyzed through the PSCAD/EMTDC simulation.

• 소음진동
• /
• 제6권1호
• /
• pp.89-95
• /
• 1996

송전전압이 500kV 이상이 되면, 송전도체의 코로나 방전에 의해 발생되는 가청소음, 험소음이 송전선로의 도체 선정에 중요한 요소가 되며 또한 바람에 의한 철탑과 도체의 풍소음도 발생한다. 본 논문은 세계최초로 765kV 2회선 교류 송전선을 개발하기 위해 건설한 한전 전력연구웜 765kV 시험송전선로의 상당 480mm$^{2}$ 도체 6가닥으로 구성된 송전선 구성에서 가정소음, 험소음, 풍소음의 통계적인 분석 결과를 나타내었다. 분석결과를 보면 6-480mm$^{2}$ 도체와 철탑구성이 가청소음 설계목표치인 50dB(A)를 만족함을 알 수 있다.