• IEIE Transactions on Smart Processing and Computing
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• 제3권6호
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• pp.372-381
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• 2014

This study examined a radar signal active cancelation technique, which is a theoretical way of achieving stealth by employing a baseband process that involves sampling the incoming hostile radar signal, analyzing its characteristics, and generating countermeasure signals to cancel out the linear-FM signal of the hostile radar signal reflected from the airborne target. To successfully perform an active cancelation, the effects of errors in the countermeasure signal were first analyzed. To generate the countermeasure signal that requires very fast and accurate processing, the down-sampling technique with the suboptimal maximum likelihood estimation (sMLE) scheme was proposed to improve the speed of the estimation process while preserving the estimation accuracy. The simulation results showed that the proposed down-sampling technique using a 2048 FFT size yields substantial power reduction despite its small FFT size and exhibits similar performance to the sMLE scheme using the 32768 FFT size.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제14권10호
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• pp.4157-4175
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• 2020

Moving target defense, as a 'game-changing' security technique for network warfare, realizes proactive defense by increasing network dynamics, uncertainty and redundancy. How to select the best countermeasure from the candidate countermeasures to maximize defense payoff becomes one of the core issues. In order to improve the dynamic analysis for existing decision-making, a novel approach of selecting the optimal countermeasure using game theory is proposed. Based on the signal game theory, a multi-stage adversary model for dynamic defense is established. Afterwards, the payoffs of candidate attack-defense strategies are quantified from the viewpoint of attack surface transfer. Then the perfect Bayesian equilibrium is calculated. The inference of attacker type is presented through signal reception and recognition. Finally the countermeasure for selecting optimal defense strategy is designed on the tradeoff between defense cost and benefit for dynamic network. A case study of attack-defense confrontation in small-scale LAN shows that the proposed approach is correct and efficient.

• Journal of Positioning, Navigation, and Timing
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• 제3권2호
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• pp.45-51
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• 2014

GNSS has the disadvantage of being vulnerable to jamming, and thus, the necessity of jamming countermeasure techniques has gradually increased. Jamming countermeasure techniques can be divided into an anti-jamming technique and a jammer localization technique. Depending on the type of a jammer, applicable techniques and performance vary significantly. Using an appropriate jamming countermeasure technique, the effect of jamming on a GNSS receiver can be attenuated, and prompt action is enabled when estimating the location of a jammer. However, if an inappropriate jamming countermeasure technique is used, a GNSS receiver may not operate in the worst case. Therefore, jammer identification is a technique that is essential for proper action. In this study, a technique that identifies a jammer based on template matching was proposed. For template matching, analysis of a received jamming signal is required; and the signal analysis was performed using a spectral correlation function. Based on a simulation, it was shown that the proposed identification of jamming signals was possible at various JNR.

• KIEE International Transactions on Power Engineering
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• 제3A권2호
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• pp.85-92
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• 2003

When a current transformer (CT) is saturated, the wave-shape of the secondary current is distorted and contains points of inflection, which correspond to the start or end of each saturation period. Discontinuity in the first-difference function of the current arises at points of inflection, where the second and third differences convert into pulses that can be used to detect saturation. This paper describes the design and evaluation of a CT saturation detection technique using the third-difference function and includes the countermeasure for a spike signal. Test results clearly demonstrate that the algorithm successfully detects the start and end of each saturation period irrespective of the remanent flux and magnetization inductance in the saturated region. This paper concludes by describing the results of hardware implementation of the algorithm using a DSP.

• 한국통신학회논문지
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• 제27권4A호
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• pp.316-323
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• 2002

본 논문에서는 표적이 대응 능력을 운용하는 상황에서 효율적인 표적 추적을 위한 십자 배열 탐색기에서의 반대응 능력을 제안하고 있다. 제안된 반대응 능력은 대응 능력과 표적을 분리하기 위해 두개의 검출 대역을 사용하고 신호 분포 특성을 사용한다. 손실된 펄스 신호로 인한 잘못된 표적 위치 검출을 피하기 위해, 제안된 반대응 능력은 이전의 표적 위치를 근거로 현재의 표적 위치를 예측한다. 십자 배열 탐색기에서 제안된 반대응 능력의 성능 평가를 위해, 다양한 조건에서 표적 신호 추출 및 표적 추적에 대한 모의 실험을 수행하였다. 모의 실험 결과들은 제안된 반대응 능력이 대응 능력을 잘 제거하면서 효율적인 표적 추적을 수행하고 있는 것을 보여준다.

• 한국통신학회논문지
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• 제21권12호
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• pp.3165-3173
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• 1996

기존의 적외선 레티클 탐색기에 대한 모델링은 주로 정적인 상황에서 이루어졌다. 본 논문에서는 레티클 탐색기의 동적 시뮬레이션 틀을 개발하고 다중 표적, 특히 섬광탄이 존재하는 상황에서 효율적인 신호처리 기법을 제안한다. 개발된 시뮬레이션 틀은 다양한 상황에서 적외서 레티클 탐색기의 성능을 분석하고 효율적인 신호처리 기법을 연구하는데 필수적인 틀이다. 섬광탄이 존재하는 환경에서 제안한 반대응 알고리즘은 간단하면서 효율적인 기법임을 실험결과로 부터 알 수 있었다.

• 정보보호학회논문지
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• 제11권4호
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• pp.15-31
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• 2001

본 논문에서는 위성통신망의 보안 위협요소를 위성통신망의 특성과 데이터를 바탕으로 Level-0(위성 전파 신호), Level-1(위성 관제 데이터). Level-2(위성 응용 데이터) 그리고 지상망 보안 단계로 분류한다. 그리고 각 보안 단계에 대한 위협 요소를 분석한다. 그 후 도출된 위성통신망 보안 위협요소에 대한 보안 요구 사항을 신호보안과 정보보안 레벨로 나누고, 이를 근거로 기존의 신호보안 수준의 대응방안에서 벗어나 위성통신 네트워크 보안, 위성통신망 시스템 보안, 위성통신망 데이터 보안등의 정보보안 레벨에서 정보보호 정책을 통한 위성통신망 보안 위협요소 대응방안을 수립한다. 이와 같은 정보보호 정책 기반의 대응방안을 통해 본 논문에서는 안전한 위성통신망 보안 구조를 제안한다.

• 한국군사과학기술학회지
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• 제4권2호
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• pp.138-146
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• 2001

The guided missile carries its own tracking radar to detect its target under noisy environments. The enemy warship uses the anti-missile electric-countermeasure(ECM) technique, such as chaff or decoy, so that the approaching guided missile could not destroy it. In this paper we propose the identification algorithm of a target signal when the enemy warship uses the chaff and decoy to deceive the guided missile. In the proposed scheme the mean square errors(MSE) between the received signals and the reference decoy signal, and between the received signals and the reference chaff signal are calculated. Then, the received signal which results in the maximum MSE is regarded as a warship signal. The performance of the proposed algorithm is verified through the computer simulation.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년 학술대회 논문집 정보 및 제어부문
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• pp.366-368
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• 2006

Electronic warfare Support(ES) system measures pulse characteristics for received RF signals that received from all directions. ES system discriminates the pulse trains that have a rule, correlationship, continuance from collected data and analyze the characteristics of the data, and identify the emitters by comparison with emitter identification data(EID). Because pulse density is very high and various signal source exists at modem signal environments, high-speed and accurate signal analysis is needed for realtime countermeasure to emitters. Grouping alleviates the load of signal analysis process and supports reliable analysis. In this paper, we suggest an adaptive clustering scheme regarding signal patterns.

• 한국정보통신학회논문지
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• 제17권12호
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• pp.2883-2890
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• 2013

전력분석공격은 알려진 값과 마스터키로부터 생성된 숨겨진 값을 입력 받아 연산하는 시점에서 이루어진다. 연산 결과값과 연산 중에 측정된 전력신호의 상관도를 분석하여 숨겨진 값을 찾아내고, 이 찾아낸 값으로 부터 마스터키를 추정할 수 있다. 그러나 전력분석을 가능하게 하는 조건을 바꾸어, 알려진 값과 연산자를 숨기거나, 숨겨진 값으로부터 마스터키의 추정이 불가능하게 하거나, 연산 결과 값과 전력신호간의 상관도를 매우 낮게 하면 전력분석공격이 매우 어렵게 된다. 이와 같은 전력분석공격을 어렵게 하는 조건을 적용한 비밀 중간키를 이용한 소프트웨어적 방어 대책을 제안한다.