• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.9 no.2
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• pp.148-154
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• 2016

In recent year, the interests of PQ is increase due to the increasing of non-linear load and distributed power sources in power system. For the parameters detection and feature extraction of PQ, and the PQ improvement method, continuous power signal monitering is needed. In this paper, the power signal compression and reconstruction method is suggested for power signal monitering. The power signal is compressed using DCT that has good compression performance, and the compressed signal is reconstructed through IDCT. And for the higher compression rate, DCT coefficients are arranged by magnitude in compression process, and in recouction process DCT coefficients are rearranged to original frequency position. The synthesized signal according to the IEC standard is used used in compression and reconstruction simulations. The performances of the proposed method are verified by comparing the error between synthesized signal and reconstructed signal.

• Proceedings of the KIEE Conference
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• 2004.07c
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• pp.1991-1993
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• 2004

가스절연개폐장치에서 발생하는 사고를 예방하기 위해서는 방전 위치 및 방전원인을 방전신호로부터 유추하는 것이 핵심 기술이다. 본 논문에서는 다양한 방전원에 대한 신호 유형을 정리하고 방전원별 특성을 추출하여 실제 부분방전 발생시 방전원을 쉽게 유추할 수 있도록 하였다.

• Journal of Satellite, Information and Communications
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• v.8 no.4
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• pp.95-99
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• 2013

GPS service is generally being used in the navigation application such as the car navigation and the smart phone. Recently, GPS service continues to increase in the timing application such as the mobile telecommunication network, the smart grid, and the financial network. As GPS signals are sensitive to GPS jamming, it should be monitored and protected. In oder to prevent and minimize the damage caused by GPS jamming, many countries are developing and operating GPS jamming monitoring system. This paper presents the implementation and the test results of the GPS jamming equipment which provides the detection, the direction finding and the location of GPS jamming.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.3
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• pp.301-306
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• 2010

In this paper, a SIT(Source Independent Tree) method for ray tracing is proposed to enhance the efficiency of tree construction with reuse of sub tree in urban environment, As the SIT method is applied, the decrease of the number of nodes for picocell and microcell simulations is 100 times. And 88~98 % of the total nodes are reused with change of location of signal source from an analysis of node reuse efficiency. Therefore the proposed SIT method is useful in performance enhancement of ray tracing, especially, for multiple antenna simulation like as MIMO system and cell planning.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.41 no.5
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• pp.9-18
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• 2004

This paper presents a vehicle detecting algorithm using microwave system signals. The Proposed algerian decides the breakpoint of signals using the likelihood criteria. The decided signals are segmented and simplified. The proposed searching algorithm uses the Euclid distance from the weighted signal data. We tested the proposed algorithm to compare with the segmentation which is a method using smoothing and edge detection. We confirm that the proposed algorithm is very useful for detecting vehicles by field test.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.11
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• pp.1023-1030
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• 2014

Beam steering algorithms using array antenna are mainly used in such a manner as anti-jamming method. However, the performance is changed according to the position of signals despite the same number of signals and the same received power. In this paper, we analyzed the effect of the position relationship of the signals on the performance of the beam steering algorithms. Therefore, we defined 'signal separation' as the minimum angle of the interference signals and the desired signal, and analysed the relationship between the C/N0 performance of beam steering algorithms as LCMV/PM and the signal separation. For simulation, we set many GPS signals and jamming signals compared to the degrees of freedom. And changed the position and the height of the receiver in order to obtain various signal separation angles. In addition, we examined the effects of signal separation and JSR on the anti-jamming performance by applying the loss factors of the received power. Through the research, there is a tendency that the performance of beam steering algorithms is increased with the increase of the signal separation, and signal separation is more severely affecting on the anti-jamming performance compared to the number of signals and JSR.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1789-1790
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• 2008

본 연구는 오류를 최소화한 초음파 수신량에 따라 구동부의 이동위치를 결정하고 이에 따른 각각의 제어신호를 출력하여 원단, 제지 등의 끝단을 정밀하게 제어함으로써 헌팅현상 등을 방지하여 물체가 더 정확한 위치에서 감기도록 유도하는 장치에 관한 것이다.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2011.04a
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• pp.57-58
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• 2011

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2004.11a
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• pp.243-243
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• 2004

• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.3
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• pp.407-416
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• 2021

An active phased array antennas can not only electrically steer the beam by controlling the weighting of the excitation signal, but can also form a pattern null in the direction of the interference source. The weight of the excitation signal to steer the main beam can be easily calculated based on the position of the radiating element. In addition, the weight of the excited signal for pattern null formation can also be calculated by setting the required radiation pattern and using WLSM(Weighted Least Squares Method). However, in a general wireless communication network environment, the location of the interference source is unknown. Therefore, an adaptive pattern null synthesis is needed. In this paper, it was confirmed that pattern null synthesis according to the required radiation characteristic was possible. And based on this, adaptive pattern null synthesis into the direction of an interference source was studied using a binary search algorithm based on observation area. As a result of conducting a simulation based on the presented technique, it was confirmed that adaptive pattern null forming into the direction of an interference is possible in efficient way.