• The Journal of Korean Institute of Next Generation Computing
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• v.13 no.4
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• pp.112-123
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• 2017

Research for the inverse estimation of RF threats and the efficient electronic attack based on the parameters of the electronic information has been active in the electronic warfare (EW) situations. In this paper, an EW transmission simulator is constructed from the modeling of radar threats, EW receivers, and propagation environments with the collected electronic information in order to verify the performance of the inverse estimation algorithm in various and practical EW situations. In simulation results, we show that the range tracking error and angle tracking error are produced within ten meters and one degree, respectively. And also, we show that the changing relations between the angle tracking error and the parameters of the monopulse angle tracking radar such as the beamwidth and squint angle in simulation results correspond with those in the theoretical modeling. Accordingly, the constructed EW simulator can be used to observe the modifying characteristics of the electronic information in transmission environments, and then, to evaluate the performance of the inverse estimation system in various EW situations.

• Journal of the Korea Society of Computer and Information
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• v.20 no.3
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• pp.97-106
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• 2015

In this paper, the development of infrared threat surrogate system is described and it can be used to verify the performance of DIRCM system. In this research, threat surrogates are manufactured using same F# and reflective optics used in 1st- and 2nd-Gen. real seeker so that the threat surrogate system can be used to develop code-based jamming techniques. Also the threat surrogate system can analyze the saturation jamming effect for image seeker using FPA detector. The result shows that 1st- and 2nd-generation threat surrogates have relatively precise tracking performance and jamming effect.

• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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• v.27 no.6
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• pp.13-19
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• 2016

• Journal of Korea Multimedia Society
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• v.8 no.1
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• pp.46-55
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• 2005

In this paper, we realize the panoramic infrared warning system to detect the small threaten object and propose the infrared image enhancement method to improve the warning ability of this system. This system composes of the sense head unit, the signal processing unit, and so on. In the proposed system, the sense head unit acquires the panoramic IR image with 360 degree field of view(FOV) by rotating the thermal sensor. The signal processing unit divides panoramic image into four sub-images with 90 degree FOV and computes the adaptive plateau value by using statistical characteristics of each subimage. Then the histogram equalization is performed for each subimage by using the adaptive plateau value. We realize the signal Processing unit by using the DSP and FPGA to perform the proposed method in real time. Experimental results show that the proposed method has better discrimination and lower false alarm rate than the conventional methods in this warning system.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.28 no.10
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• pp.810-818
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• 2017

This paper presents the approaching target above ground tracking based on Kalman filter applied to the proximity sensor for the active defense system. The proximity sensor located on the front of the countermeasure is not easy to detect when the anti-tank threat enters a fragment dispersion range due to limited antenna beamwidth. In addition, it is difficult for the proximity sensor to detect the anti-tank threat accurately at a terrestrial environment including various clutters. To solve these problems, this study presents the approaching target above ground tracking based on Kalman filter and applies the novel estimation method for a noise covariance matrix to improve a tracking performance. Then, a high tracking performance of Kalman filter applied the proposed noise covariance matrix is presented through field firing test results and the validity of the proposed study is examined.

• The Journal of Korean Institute of Next Generation Computing
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• v.13 no.4
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• pp.29-39
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• 2017

Various electronic warfare situations drive the need to develop an integrated electronic warfare simulator that can perform electronic warfare modeling and simulation on radar threats. In this paper, we analyze the components of a simulation system to reversely model the radar threats that emit electromagnetic signals based on the parameters of the electronic information, and propose a method to gradually maintain the reverse extrapolation model of RF threats. In the experiment, we will evaluate the effectiveness of the incremental model update and also assess the integration method of reverse extrapolation models. The individual model of RF threats are constructed by using decision tree, naive Bayesian classifier, artificial neural network, and clustering algorithms through Euclidean distance and cosine similarity measurement, respectively. Experimental results show that the accuracy of reverse extrapolation models improves, while the size of the threat sample increases. In addition, we use voting, weighted voting, and the Dempster-Shafer algorithm to integrate the results of the five different models of RF threats. As a result, the final decision of reverse extrapolation through the Dempster-Shafer algorithm shows the best performance in its accuracy.

• Review of KIISC
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• v.30 no.2
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• pp.49-57
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• 2020

군사 등의 특수 목적으로만 사용되었던 무인비행체 드론이 최근 상용 수준의 간결한 구조와 저가화가 가능해지면서 여러 제조업체를 통하여 민간분야의 다양한 응용에 활용 가능함을 증명하고 있다. 그러나 제조업체들 간의 시장 우위 선점을 위한 과열 경쟁으로 인하여 보안 안전성 검증 단계를 거치지 않은 드론과 이에 수반되는 애플리케이션이 시장에 바로 출시되면서 이들이 우리 사회를 향한 공격도구로 활용될 수 있다는 새로운 잠재적 위협이 우려되고 있다, 이와 관련하여 현재 드론과 애플리케이션과의 연결 및 데이터 통신 과정에서 완성도가 낮은 접근제어 기술이나 암호화되지 않은 통신방식을 비롯하여 드론 내부 소프트웨어의 코딩 상의 문제점 등에 의하여 다양한 취약점이 노출되고 있는 상태이다. 이러한 취약점들로 인하여 드론의 인증 해제 및 하이재킹을 통한 불법 영상촬영이나 개인정보의 유출 등을 비롯하여 특정 목표물을 향한 드론의 고의적 추락 등이 발생할 경우 재산 피해뿐만 아니라 인명 피해까지 발생할 수 있다. 특히, 현재의 드론 응용은 초기단계여서 향후 다양한 응용과 유관 기술들이 폭넓게 전개되어야 하는 시점에서 이러한 사고 가능성은 매우 심각하게 인식되어야 할 것이다. 더구나 제4차 산업혁명 시대의 드론은 비상시를 위한 다이나믹 모바일 게이트웨이 역할까지도 수행하여야 하는 환경에서 악의적인 행위는 전체 사회로 확산될 우려도 있으므로 미래 사회의 드론을 위한 안전문제는 매우 시급하고 중대하다고 할 수 있다. 이에 본 고에서는 현재까지 발표된 드론에 대한 다양한 보안위협을 조사하고 이러한 보안 위협을 요소별로 분류하여 정리하였다. 본 기고가 간단하게나마 정리한 내용을 통하여 다양한 보안위협에 대한 대응기술을 준비하기 위한 시발점이 되었으면 한다.

• Journal of the Korean Society for Precision Engineering
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• v.33 no.12
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• pp.1039-1045
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• 2016

We investigated the protection capability of a plate against high speed projectiles demonstrating collision and penetration behaviors by finite element analysis. The element erosion method was used for penetration analysis, which showed that the speed of the projectile was slightly reduced by the collision with the protection plate. Protection capability was measured by the projectile's attitude angle change because the damage of our tanks by projectiles was also dependent on the projectile-tank collision angle. When the length of the protection plate was sufficiently long, the projectile was severely deformed and incapacitated. In the case of a small plate, the projectile was deformed only in the collision region. Thus, projection capability was investigated by the change of attitude angle. The effect of collision angle, velocity, and length of the plate on the rotational and vertical velocities of the projectile was investigated.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.41 no.11
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• pp.1065-1075
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• 2017

In this study, high velocity impact tests along with modeling of material behavior and numerical analyses were conducted to predict the dispersion behavior of the debris resulting from a high velocity impact fracture. For the impact tests, two different materials were employed for both the projectile and the target plate - the first setup employed aluminum alloy while the second employed steel. The projectile impacts the target plate with a velocity of approximately 1 km/s were enforced to generate the impact damages in the aluminum witness plate through the fracture debris. It was confirmed that, depending on the material employed, the debris dispersion behavior as well as the dispersion radii on the witness plate varied. A numerical analysis was conducted for the same impact test conditions. The smoothed particle hydrodynamics (SPH)-finite element (FE) coupled technique was then applied to model the fracture and damage upon the debris. The experimental and numerical results for the diameters of the perforation holes in the target plate and the debris dispersion radii on the witness plate were in agreement within a 5％ error. In addition, the impact test using steel was found to be more threatening as proven by the larger debris dispersion radius.

• Journal of the korean veterinary medical association
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• v.44 no.3
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• pp.269-280
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• 2008