• Proceedings of the KIEE Conference
• /
• 1998.11c
• /
• pp.935-937
• /
• 1998

The stringing load was added to tower design that consider the active load in 765kV transmission line construction. The nominal auxiliary members of steell tubular tower arm were altered into stress members by means of three dimensional design analysis method. 765kV transmission line construction also use self-standing tower that does not install temporary wire which support the section tower placed between drum field and engine field when stringing process.

• The Transactions of the Korean Institute of Electrical Engineers
• /
• v.41 no.5
• /
• pp.445-458
• /
• 1992

As one of the forced cooling method of the underground power transmission system, external water cooled system with trough in tunnel was investigated. This study is performed on thermal analysis for a standard condition to determine the cable transmission current of the underground power transmission system about the cooling facility. A parametric study was performed for the inlet water temperatures, flow rates, the inlet air velocities, flow rates and the cooling spans. This study shows that the cable transmission current varies within the allowable limitation in compliance with the variation of inlet water temperatures and flow rates. It exhibits little variations for the most intervals in compliance with the variation of inlet air temperatures and flows. But, the cable transmission current fast reduces for a specified interval and consequently affects the underground transmission system. As a result, when the actual forced cooling system is designed, the design conditions of inlet air have to be considered as the most important parameters in determination of the cable transmission current.

• Proceedings of the KIEE Conference
• /
• 1996.07b
• /
• pp.646-651
• /
• 1996

This paper presents the study results of four transmission methods to enchance transmission capability. The four transmission methods studied were FACTS, HVDC, High Phase Order and new conductor material method. The study was Performed based on mid and long term KEPCO system in 2000 and 2006 year. Among them FACTS(Flexible AC Transmission System) is an exciting new field which holds great promise for improved utilization of AC transmission systems.

• Journal of Electrical Engineering and Technology
• /
• v.2 no.2
• /
• pp.194-200
• /
• 2007

The deregulation problem has recently attracted attentions in a competitive electric power market, where the cost must be earmarked fairly and precisely for the customers and the Independent Power Producers (IPPs) as well. Transmission loss is an one of several important factors that determines power transmission cost. Because the cost caused by transmission losses is about $3{\sim}5%$, it is important to allocate transmission losses into each bus in a power system. This paper presents the new algorithm to allocate transmission losses based on an integration method using the loss sensitivity. It provides the buswise incremental transmission losses through the calculation of load ratios considering the transaction strategy of an overall system. The performance of the proposed algorithm is evaluated by the case studies carried out on the WSCC 9-bus and IEEE 14-bus systems.

• Proceedings of the KIEE Conference
• /
• 1998.07c
• /
• pp.1235-1237
• /
• 1998

Spacer Dampers must be carefully designed and tested. Because it can protect conductors from conductor oscillations due to winds and electrical forces. If the spacer damper has any problems in itself, it may cause extensive damage to the transmission lines. This paper suggests a design method and considerations of spacer damper for bundled conductor transmission lines.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.12 no.7
• /
• pp.1157-1166
• /
• 2001

In this paper, we investigated the degree of compensation for optical pulse shape distortion due to both chromatic dispersion and SPM(self phase modulation) in high speed optical transmission system with dispersion shift fiber. We adopted the power symmetric MSSI(mid-span spectral inversion) as compensation method. We used EOP(eye-opening penalty) parameter in order to evaluate the compensation efficiency of distorted optical pulse. We evaluated input signal power range being able to maintain stable reception performance in the case of various chirp parameter of modulated optical pulse. And, in order to verify the applicable to wideband WDM system, we evaluated the wavelength range being able to maintain stable reception performance through the EOP calculation of various dispersion coefficient of first fiber D$\_$11/. We showed that proposed MSSI is effective compensation method to down chirped optical pulse transmission rather than up chirped optical pulse transmission in anomalous dispersion range. And we showed that this method have possibility of relative high power transmission and wideband transmission in WDM system.

• Proceedings of the KIEE Conference
• /
• 2000.07a
• /
• pp.428-430
• /
• 2000

This paper describes under-ground transmission cable sheath voltage by using EMTP and proposes a new design method for calculating cable sheath voltage in steady state. The cross bonding system of power cable is modeled on ${\pi}$ equivalent circuit and the sheath voltage(current) of cable can be analyzed with comparing to conventional method.

• Proceedings of the KSR Conference
• /
• 2001.05a
• /
• pp.155-161
• /
• 2001

In order to evaluate the sound transmission loss of a structure, a large reverberation room described by ISO is generally used. ISO test method is however for architectural structures, which is not properly implemented for small mechanical structures, such as rolling stocks. In this paper, evaluation procedure for railway vehicle structures has been proposed.

• Journal of the Institute of Electronics Engineers of Korea SP
• /
• v.39 no.3
• /
• pp.36-41
• /
• 2002

Generally, cartoon images are simple and involve a small number of colors and often include large homogeneous regions with same color or gradient. In this paper, effective compression method for complementary quadtree was suggested for cartoon images, by using those properties. And with progressive transmission, this method involves a progressive increase in the image resolution at the receiver from a lower to a higher resolution during the transmission of data. This is an effective way of using a limited transmission channel, because, after estimating the value of the data in the early transmission period, a decision can be made whether or not to proceed with the transmission of the remaining part. Since the proposed method is lossless and involves progressive transmission, it was compared with progressive PNG and progressive GIF, which had same functions.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.37B no.9
• /
• pp.734-740
• /
• 2012

In this paper, we propose a method for throughput improvement in multirate multihop wireless networks with intra-session network coding. A multirate transmission supports several rates so that it has a tradeoff between transmission rate and transmission range, therefore multirate can cope with the performance degradation. We present the rate selection method with intra-session network coding in multirate nodes. The effective transmission rate is calculated by using intra-session network coding, and then its maximum effective transmission rate is selected. Concurrent transmission set is determined by selected transmission rate and then the linear programming is formulated for throughput calculation in multihop wireless networks. We evaluate the performance by using MATLAB and lp_solve programs in two topologies. It is shown that the throughput of the proposed method is improved.