• Proceedings of the KIPE Conference
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• 2008.06a
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• pp.351-353
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• 2008

최근에 환경친화적인 관점에서 많은 형태의 무수은을 이용한 형광램프가 연구되어오고 있다. 그 중에서도 제논을 이용한 형광램프는 수은을 대체하는 방전기체의 조건을 만족하고 있다. 따라서 제논을 이용한 면광원의 구동 시 지금의 수은이 들어간 광원의 구동에 있어서 안정기요건이 차이가 있으므로, 본 논문에서 제논을 이용한 면광원을 위한 안정기를 제안한다. 제안된 면광원 안정기는 크게 AC입력 측의 PFC (power factor correction)부분과 면광원을 구동하는 인버터 부분으로 구성되어있다. 특히, 인버터 부분에서는 제논 면광원의 특성에 대응하기 위해서 정전력회로, 아크 방지 기동회로 등이 포함되어 있다.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.41 no.10
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• pp.17-26
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• 2004

This paper proposes JBSTBC (Joint Beamforming Space-Time Block Coding) scheme for MIMO (Multi-Input Multi-Output) communication systems. To enhance the order of spatial diversity in presence of deteriorative fading correlations as well as inter-substream interferences, the proposed JBSTBC method employs joint eigen-beamforming technique together with the BOLD (block-ordered layered detector) for MIMO-STBC. In order to confirm superiority of the proposed JBSTBC method, the computer simulations are conducted in highly correlated fading situations with providing detailed mathematical derivations for clarifying functionality of the proposed scheme.

• Proceedings of the KIPE Conference
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• 2013.07a
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• pp.491-492
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• 2013

본 연구는 STATCOM을 이용하여 고속철도 급전 계통의 전압 변화를 보상하는 기법에 관한 것이다. 기존의 PI 제어기를 이용한 제어기법를 대신하여 본 연구에서는 퍼지제어기(FLC) 적용을 제안하며, 퍼지제어기와 PI제어기의 제어결과를 비교한다. 퍼지제어기를 통해 내부 파라미터 변동이나 외부의 환경 변화 등 계통의 변화시에 정상상태 편차, 정상상태 도달 시간 등을 최소화 시킬 수 있음을 보인다.

• Proceedings of the KIPE Conference
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• 2017.07a
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• pp.134-135
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• 2017

태양광 패널 등가모델을 결합한 태양광 발전 패널 모의 장치(SAS)는 정확도 면에서 많은 장점이 있다. 특히 SAS에서 사용되는 등가회로 모델은 주변 환경에 맞게 빠르게 변하는 I-V 출력특성을 추출하며, 추출시간이 짧다. 이러한 방법을 이용하려면 제어기를 주목해야하는데, 보통 전압 또는 전류 제어기 하나만 사용한다. 하지만 Fill factor가 높은 패널인 경우, 전압 또는 전류제어기 하나만 사용하여서는 제어가 잘 되지 않기 때문에 본 논문에서는 전압과 전류제어기 모두 사용하되, 필요에 따라 스위칭 하여 사용하는 하이브리드 제어기법을 제안한다. 이러한 기법을 통하여 모두 제어가 가능한 기법을 제안한다.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.39 no.6
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• pp.709-717
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• 2002

A new multi constant modulus algorithm (MCMA) for a blind decision feedback equalizer is proposed. In order to avoid the error propagation problem in the conventional DFE structure, Feed-Back Filter coefficients are updated only after Feed-Forward Filter coefficients are sufficiently converged to the steady state. Therefore, it has the problem of slow convergence speed characteristics. To overcome this drawback, the proposed MCMA algorithm uses not only new cost function considering the minimum distance between the received signal and the representative value containing the statistical characteristics of the transmitted signal, but also adaptive step-size according to the equalizer outputs to fast convergence speed of FBF. Simulations were carried out under the certified communication channel environment to evaluate a performance of the proposed equalizer. The simulation results show that the proposed equalizer has an improved convergence and SER performance compared with previous methods. The proposed techniques offer the possibility of practical equalization for cable modem and terrestrial HDTV broadcast (using 8-VSB or 64-QAM) applications.

• Journal of Aerospace System Engineering
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• v.10 no.4
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• pp.84-89
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• 2016

Electronic Warfare (EW) is the mission area responsible to establish and maintain a favorable position in the electromagnetic domain. Testing and Evaluation of EW devices on modern military aircraft to pursue this critical mission area require the use of a wide range of techniques and analytical methods to assure users of the readiness of EW system to meet the challenge of a combat environment. This paper is intended as an introductory text dedicated to EW systems (especially RWR, CMDS) test and evaluation techniques and will serve experienced engineers and program managers, as well as novice engineers, as a concise reference for EW systems' test and evaluation processes and testing resources.

• Electronics and Telecommunications Trends
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• v.16 no.5 s.71
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• pp.151-160
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• 2001

본 논문은 댁내통신설비 구축에 필요한 설치 공간과 운용조건에 해당하는 환경 요소들에 대한 체계를 분석하여 정리한 것이다. 댁내통신설비기술의 부문으로서 구조화된 배선시스템이 그 중추를 이루고 있으며, 이에 필요한 광커넥터, 트랜시버 등 핵심 접속 자재, 보호기, 복합 세대단자함 또는 게이트웨이 등이 개발되고 있다. 이에 더하여 댁내통신설비의 근간이 되는 배선시스템을 최적으로 수용하고 운용할 수 있는 공간과 환경이 갖추어져야 한다. 본 논문에서는 이러한 공간과 환경에 대하여 국내외 표준자료와 기술규격 자료, 설치시방서와 연구논문 등을 분석하여 아직 체계적으로 정리되어 있지 않은 공간과 환경 요소들을 분류 정리한 것이다.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.44 no.3
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• pp.51-57
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• 2007

Without human dynamics effects, the manually operated target tracking system has poor performance or instability in real environments. The tracking system is invalid when a human is added to the control loop as a real time delay, because input signals are generated by human operator to reduce the errors between target and gun. In this paper, we consider the human operator as a part of controller and modeling the human operator as a first-order model to generate the intentional force. But it is known that human modeling is not easy because of disturbance or noise of the vehicle while moving for the target. We performed a variety of experiments with real plant to identify the model's parameters and verify the proposed operator model's efficiency.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.6A
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• pp.611-621
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• 2010

When an enemy platforms transmit electronic jamming or tracking interference signal to a friendly ship's radar, the radar have to avoid the jamming and to track targets continually without losing the targets with the electronic protection techniques. Electronic protection is an essential key for a platform to survive in electronic warfare, for this purpose, jamming simulator was developed to provide electronic warfare environments for the test and evaluate the effectiveness of radar's electronic protection techniques. Jamming simulator has ability to generate a variety of deception and noise jamming signals using the DRFM which minimize phase distortions of 1GHz broadband radar signal with the phase sampling method. This paper presents the design contents of the jamming simulator to process the analysis of broadband radar signal and generate jamming signal, also proposes the algorithms of the deception and noise jamming and verifies the effectiveness of the simulator by field trial.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.42 no.3
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• pp.639-648
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• 2017

Electronic warfare systems for extracting information of the threat signals can be employed under the circumstance where the power of the received signal is weak. To precisely and rapidly detect the threat signals, it is required to use methods exploiting whole energy of the received signals instead of conventional methods using a single received signal input. To utilize the whole energy, numerous sizes of windows need to be implemented in a detector for dealing with all possible unknown length of the received signal because it is assumed that there is no preliminary information of the uncooperative signals. However, this grid search method requires too large computational complexity to be practically implemented. In order to resolve this complexity problem, an approach that reduces the number of windows by selecting the smaller number of representative windows can be considered. However, each representative window in this approach needs to cover a certain amount of interval divided from the considering range. Consequently, the discordance between the length of the received signal and the window sizes results in degradation of the detection performance. Therefore, we propose the weighted energy detector which results in improved detection performance comparing with the conventional energy detector under circumstance where the window size is smaller than the length of the received signal. In addition, it is shown that the proposed method exhibits the same performance under other circumstances.