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측정된 전자파 차폐율을 이용한 시스템 내부 침투파형 예측
강래충,Kang, Rae-Choong 한국군사과학기술학회 2011 한국군사과학기술학회지 Vol.14 No.6
The HEMP has very short rising time with several tens of kV/m, and very dangerous to almost of the electronics. And the certain level of EMP shielding effectiveness is necessary for mos t of the systems andequipment. In EMP shielding effectiveness, the peak value and the rising time in the system are the most considerable parameters. In order to find out these parameters, we need to estimate the pulse shape in time domain. In this paper, we propose the methods to estimate the penetrated pulse in time domain using measured shielding effectiveness and digital filter modeling technique. The validity of the Digital filter modeling technique is verified by the HFSS.
항공기 전기체 낙뢰 간접영향 시험에서의 측정파형 분리 방법
강래충 한국항공우주학회 2023 韓國航空宇宙學會誌 Vol.51 No.8
Through the aircraft lightning indirect effect test that applies a reduced lightning current to the aircraft and measures the current and voltage waveform induced in the internal cable, we can predict the threat level that the equipment will face when the aircraft is struck by lightning. However, since the measured waveform is a complex shape unlike the standard test waveform which is used for lighting test on equipment level, it is difficult to directly compare it with the standard waveform. Therefore, it is necessary to separate the measured waveform into standard waveform. We used the Norm analysis method proposed in ‘SAE ARP 5415B’ to separate the measured waveform. The key of the Norm analysis method is to remove noise from the measured waveform. For this purpose, this paper proposed the zero phase low-pass filtering method. In addition, an envelope detection method was proposed as an alternative to solve the peak loss caused by applying a low-pass filter to a waveform containing oscillatory component. 축소된 낙뢰 전류를 항공기에 인가하고 내부 케이블에 유도된 전류 및 전압 파형을 측정하는 항공기 전기체 낙뢰 간접영향 시험을 통해 항공기가 낙뢰에 타격 되었을 때 장비가 겪게 되는 위협 수준을 예측할 수 있다. 그러나 측정된 파형은 장비 단위 낙뢰 간접영향 시험에 사용되는 표준 시험 파형과 다르게 복잡한 형태이므로 직접적인 비교가 어렵다. 따라서 측정 파형을 표준 파형의 형태로 분리할 필요가 있으며, ‘SAE ARP 5415B’에서 제안한 Norm 분석 방법을 사용하였다. Norm 분석 방법의 핵심은 측정된 파형에서 노이즈를 제거하는 것이다. 이를 위해 본 논문에서는 영위상 저주파 통과 필터를 제시하였다. 그리고 진동성분을 포함한 파형에 저역 통과 필터를 적용함으로써 발생하는 첨두치의 손실을 해결하기 위한 대안으로 포락선 검출 방법을 제시하였다.
강래충(Raechoong Kang),최희승(Heeseung Choi),김재희(Jaihie Kim) 대한전자공학회 2007 대한전자공학회 학술대회 Vol.2007 No.7
Fake fingersubmission to the sensor is a major problem in fingerprint recognition systems. In this paper, we introduce a novel liveness detection method using multi-static features. For convenience and usefulness of field application, static features are only considered to detect 'live' and 'fake' fingerprint images. Individual pore spacing, noise of image and first order statistics of image are analyzed as our static features to reflect the physiological and statistical characteristics of live and fake fingerprint.
강래충(Raechoong Kang),최희승(Heeseung Choi),김재희(Jaihie Kim) 대한전자공학회 2007 대한전자공학회 학술대회 Vol.2007 No.11
Fake fingersubmission to the sensor is a major problem in fingerprint recognition systems. In this paper, we introduce a novel liveness detection method using power sepctrum analysis. This algorithm needs only single fingeprint image for liveness detection.
접지면 위 도선에 대한 고고도 전자기 펄스 신호의 결합 특성 분석
이진호,권준혁,신규범,강래충,Lee, Jin-Ho,Kwon, Joon-Hyuck,Shin, Guy-Beom,Kang, Rae-Choong 한국군사과학기술학회 2010 한국군사과학기술학회지 Vol.13 No.6
Since HEMP has the very short rising time and propagates widespreadly with several tens of kV/m, it threatens most of systems in its cover range. Therefore, it is important to research coupling mechanism into systems and establish countermeasures for the HEMP to protect systems effectively. This paper analyzed characteristics and trends of currents to be induced at the load of a line which is located over ground with different conditions such as polarization, incidence angle, line length and height etc. We applied double exponential waveform as the HEMP shape and used BLT method to analyze the coupling route into the line. Also, we compared the simulation data of chain matrix modeling to verify reliability of BLT modeling. In the result, two data is almost agreed.