• Proceedings of the KIEE Conference
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• 1984.07a
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• pp.237-239
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• 1984

• Proceedings of the KIEE Conference
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• 2001.05a
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• pp.226-229
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• 2001

The combined transmission lines with the underground power cables are continuously expanded in power systems. So the fault of combined transmission line is increased every year as the complication of underground transmission line. In this paper. traveling wave theory and DWT wavelet transform are used for fast and accurate detection of fault location at the combined transmission line. Traveling wave travels to each bus like surge and repeats reflection and transmission till transient signal is completely disappeared. When fault is occurred on overhead and underground tine, the fault location detecting algorithm was performed with using continuous peak value time-delay of traveling wave reflected from A bus.

• Proceedings of the KIEE Conference
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• 2003.07a
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• pp.348-350
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• 2003

In recent years, with the continuous development of modem power system, the need for high performance protection to meet the customers' requests for more stable and reliable power supply has become increasingly emphasized. So, there is urgent need for a proper testing platform about not only existing digital protection relay but also new digital protection relay on the transmission line. It is also dynamic-state test which can test the performance of digital relay. This paper suggests basic system model for testing transmission line protection using PSCAD/EMTDC, and presents the process of the component modeling in the basic system.

• Journal of the Korean Institute of Telematics and Electronics
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• v.11 no.4
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• pp.25-29
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• 1974

In this paper, a surfer wide-band FM lossy-line discriminator is investigated, as it has the merit of rediucing the dimensions of the discriminator by using proper dielectric material in the transmission tine. It is shown that the lossy-line discriminator that is made of a pair of the transmission lines satisfying the distortionless condition approximately gives almost no more deterioration in its characteristics than the ideal-line FM discriminator, while the dimensions of the transmission lines of the discriminator can be reduced greatly.

• Proceedings of the KIEE Conference
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• 2003.11a
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• pp.334-336
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• 2003

This paper describes the influences of the large scaled wind farm interconnected with 154 kV power networks on the operational characteristics of distance relay applied in the transmission line. The wind farm composed of wind turbine generators are one of the great energy sources: they can supply the power into an interconnected network not only the normal conditions, but also the fault conditions of power network. Therefore, the distance relay applied in the transmission tine may mal-operate due to the contribution of wind farm. This paper presents the operational characteristics of distance relay for the fault occurred in the transmission line interconnected with wind farm. Simulation results show that it is difficult to recognize the fault location due to the power output of wind farm.

• Proceedings of the KIEE Conference
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• 2001.11b
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• pp.399-402
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• 2001

In this paper, 3-dimensional charge simulation method was applied to analyze electric field distributions of special conductor bundles equipped with spiral rods for reducing aeolian noise in a corona cage. Comparing electric field distributions of special conductor bundles in 765kV transmission tine with ones in corona case, we decide experimental voltages of special conductor bundles in corona cage.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2004.05b
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• pp.154-157
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• 2004

A realization for the wireless transmission system on the Un image using embedded server is presented on the paper to be simply to omni-direction data acquisition. The embedded system is composed of the image data acquisition which has CMOS sensor and lame grabber, the embedded server that takes the wireless LAN target board, and client part that is monitoring the image from the embedded server. The experiment result is average 12.7fps in 8bit on the 320$\times$240, 4:2:2 YCbCr. The system enable images transmission to be soft . monitoring.

• 한국초전도학회:학술대회논문집
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• v.10
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• pp.193-196
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• 2000

A new type low-pass filter design method based on a coupled line and transmission line theory is proposed to suppress harmonics by attenuation poles in the stop band. The design formula are derived using the equivalent circuit of a coupled transmission line. The new low-pass filter structure is shown to have attractive properties such as compact size, wide stop band range and low insertion loss. The seventh-order low-pass filter designed by present method has a cutoff frequency of 0.9 CHz with a 0.01 dB ripple level. The coupled line type low-pass filter with strip line configuration was fabricated by using a high-temperature superconducting (HTS : YBa$_2$Cu$_3$O$_{7-{\delta}}$ thin film on MgO(100) substrate. Since the HTS coupled tine type low-pass filter was proposed with five attenuation poles in stop band such as 1.8, 2.5, 4, 5.5, 6.2 GHz. The fabricated low-pass filter has improved the attenuation characteristics up to seven times of the cutoff frequency.

• Transactions of the Korean Society of Automotive Engineers
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• v.4 no.2
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• pp.90-105
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• 1996

A real tine simulator of running power train for a construction vehicle was developed. The simulator mainly consists of following two parts; (1) running power train part and (2) running load generation part. An optimal servo control algorithm was adopted for designing the multi-variable digital control system of the simulator. By experiments investigating response characteristics under step-wise variation or pre-determined scenario of target vehicle velocity and target load torque, it was verified that the simulator could reproduce physical situations at and actual vehicle with excellent similarity.

• Proceedings of the KIEE Conference
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• 2006.10c
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• pp.515-517
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• 2006

Recently, there is a rapidly growing demand for efficient real-tine playback and transmission of large amounts of multimedia data. But most users' connections are not fast enough to download large chunks of multimedia data. Therefore a streaming technology is needed in which users enable the real-time playback of multimedia date without having to download the whole of the multimedia date. In this paper, we propose a personalized IP streaming system. The proposed IP streaming system enables users to got an intelligent recommendation of multimedia contents based on the user preference information stored on the streaming server or the home media server. Moreover, users are assured of seamless access of streamed content event if they switch to another client device by implementing streaming system based on user identification and device information. We evaluate our approach with simulation results.