• 융합보안논문지
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• 제19권3호
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• pp.109-115
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• 2019

북의 단거리 발사체 및 미사일은 S-300 계열 이스칸데르급으로 사거리는 270-420km, 고도는 40-50km 내에서 타격이 가능한 무기체계로 우리가 보유하고 있는 탐지레이더나 타격무기로는 대응이 매우 어렵다. 북이 서울 불바다를 운운하는 것도 이러한 단거리 로켓과 미사일에 핵이나 화학무기를 장착하여 수도권을 타격하겠다는 의도를 파악 할 수 있기 때문에 하루 빨리 대응무기의 전력화나 도입이 매우 시급하다. 북의 단거리 미사일 방어에 즉각 대응하기 위한 무기체계로 이스라엘에서 운용하고 있는 아이언 돔 및 아이언 빔 체계가 적합함으로 조기 도입하고 장기적으로 국내 자체적으로 단거리 미사일 방어를 위한 한국형 미사일방어와 타격체계인 Kill Chain을 지속 개발하고 국방과학연구소, 한국과학기술원, 방산 업체들과 협업하여 자체 기술력 확보로 북의 무모한 도발에 상시 대비할 수 있도록 만반의 준비태세를 갖추어야 하겠다.

• 한국군사과학기술학회지
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• 제21권2호
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• pp.166-172
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• 2018

To develop and evaluate the real-time SAR(Synthetic Aperture Radar) motion measurement system, true antenna phase center(APC) positions during SAT(Synthetic Aperture Time) are needed. In this paper, CDGPS(Carrier phase Differential Global Positioning System) post processing method is proposed to get the true APC position for spotlight SAR image formation. The CDGPS position is smoothed to remove high frequency noise which exists inherently in the carrier phase measurement. This paper shows smoothed CDGPS data is enough to provide the true APC for high-quality SAR image formation through motion measurement result, phase error estimation and IRF(Impulse Response Function) analysis.

• 한국군사과학기술학회지
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• 제23권4호
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• pp.407-416
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• 2020

Recent complex battle field demands Network Centric Warfare(NCW) ability to control various parts into a cohesive unit. In path planning filed, the NCW ability increases complexity of path planning algorithm, and it has to consider a communication coverage map as well as traditional parameters such as minimum radar exposure and survivability. In this paper, pros and cons of various propagation models are summarized, and we suggest a coverage map generation method using a Longley-Rice propagation model. Previous coverage map based on line of sight has significant discontinuities that limits selection of path planning algorithms such as Dijkstra and fast marching only. If there is method to remove discontinuities in the coverage map, optimization based path planning algorithms such as trajectory optimization and Particle Swarm Optimization(PSO) can also be used. In this paper, the Longley-Rice propagation model is used to calculate continuous RF strengths, and convert the strength data using smoothed leaky BER for the coverage map. In addition, we also suggest other types of rough coverage map generation using a lookup table method with simple inputs such as terrain type and antenna heights only. The implemented communication coverage map can be used various path planning algorithms, especially in the optimization based algorithms.

• 한국군사과학기술학회지
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• 제16권4호
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• pp.523-536
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• 2013

A recent air defense missile system is required to have a capability to intercept short-range super-high speed targets such as tactical ballistic missile(TBMs) by performing engagement control efficiently. Since flight time and distance of TBM are very short, the missile defense system should be ready to engage a TBM as soon as it takes an indication of the TBM launch. As a result, it has to predict TBM trajectory accurately with cueing information received from an early warning system, and designate search direction and volume for own radar to detect/track TBM as fast as it can, and also generate necessary engagement information. In addition, it is needed to engage TBM accurately via transmitting tracked TBM position and velocity data to the corresponding intercept missiles. In this paper, we proposed a method to estimate TBM trajectory based on the Kepler's law for the missile system to detect and track TBM using the cueing information received before the TBM arrives the apogee of the ballistic trajectory, and analyzed the bias of prediction error in terms of the transmission period of cueing data between the missile system and the early warning system.

• 한국군사과학기술학회지
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• 제20권4호
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• pp.558-565
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• 2017

The vehicle-mounted mine detection system with large detection sensor modules can search wide areas with a fast detection speed. To mount the heavy mine detectors on a manned or unmanned vehicle, it is necessary to design the detector driving mechanism and control system based on the considerations driven from the characteristic analysis and the operation requirements of the detection system. Furthermore, while operating the mine detector mounted on a mobile vehicle, it is significant to keep the height from the ground to sensors within a certain distance in order to get a qualified detection performance. As the mine detection sensor, we used ground penetrating radar widely used to geotechnical exploration, mine detection and etc. In this paper, we introduce a driving mechanism through analyzing the characteristics of the vehicle-mounted mine detection system. We also suggest a method to automatically control the distance between the ground and GPR by utilizing the GPR output values, used to detect mines at the same time.

• 수산해양기술연구
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• 제50권3호
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• pp.252-261
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• 2014

Marine casualties originated from fishing vessel occupied about 70% of the whole marine casualties in Korea from 2001 to 2010, this ratio was not much changed as it was before. Therefore a pragmatic counterplan to decrease of casualties in fishing vessel is indispensable for reduction of the nationwide marine casualties. But since the casualties occurred by fishing vessel may have a different causes and counterplan according to the operating type of it, in this paper, fishing vessels classified into 12 types by operating method and inspected the causes and counterplan for that. The operating type of fishing vessel occurred the specific casualties more were jig boat in collisions and fire explosion, trap fishing boat, mixed fishing boats and inshore gill netter in collisions, stow netter in machinery damages and capsizing, offshore gill netter in machinery damages, fish carrier in collisions. It must be emphasized that the higher ranked types of vessels, especially jig boat have to take special care to the approaching vessels under way, trap fishing boat to rear look out and mixed fishing boat must keep on safety speed and be taken an education for advance the skill of operating radar as well. For all 12 types of fishing vessel, it is necessary for an operator to make strict precaution on the other vessel under way systematically and keep the regulation for preventing collisions, and for an engineer on watch to make a check the electricity and the engines periodically for reduction the fire explosion and machinery damages.

• 한국추진공학회지
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• 제23권5호
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• pp.27-35
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• 2019

스텔스 기술은 레이더 및 적외선 시커와 같은 탐지기로부터의 탐지를 피하는 기술이다. 특히 IR 미사일은 항공기 자체의 열을 감지하기 때문에 적외선 신호에 의한 탐지는 더욱 위협적이며 적외선 스텔스 기술은 항공기 및 UCAV(Unmanned Combat Aerial Vehicle)의 생존을 보장하는데 필수적이다. 본 연구에서는 UCAV 노즐 설계에 따른 공력 및 적외선 스텔스 성능 분석이 수행되었다. 수치해석 결과에 따르면 Double S형 노즐은 엔진의 고온부를 차폐할 수 있기 때문에 적외선 신호를 줄이는 데 효과적이다. 또한, Double S형 노즐에서 회전부 위치가 뒤쪽에 위치할수록 적외선 신호가 감소함을 확인하였다.

• 한국정보통신학회논문지
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• 제23권9호
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• pp.1088-1095
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• 2019

최근 발전되고 있는 정보통신 IT 기술은 자동차 시장에도 큰 영향을 미치며 발전하고 있다. 근래에는 운전자의 안전성과 편의성을 위해 IT 기술이 접목된 장치들이 장착되고 있다. 하지만 편의성이 증가된 장점과 함께 운전자의 주의 분산으로 인해 교통사고를 증가시키는 단점도 가져오게 되었다. 이러한 사고를 미연에 방지하기 위해 여러 방식과 종류의 안전시스템 개발이 필요하다. 본 논문에서는 두 개 이상의 센서를 이용한 레이더센서 와 카메라 융합 방식 및 Stereo Camera 방식을 이용하지 않고 하나의 단일 Camera를 이용하여 주/야간 차선이탈 경보 및 장애물 및 보행자 인식이 가능한 플랫폼을 구현 하고 차량에서 인식률 평가 및 유효성을 분석 하여 단일 카메라를 이용한 다기능 주행안전 플랫폼 연구를 제안 한다.

• 한국정보전자통신기술학회논문지
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• 제15권5호
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• pp.343-348
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• 2022

STAP 시스템은 레이더 신호의 클러터와 재밍을 억제하지만 최적의 성능을 위해서는 많은 수의 샘플이 필요하다. 많은 수의 샘플은 처리 계산을 증가시키기 때문에 신호 랭크를 감소키기 위한 변환 방법이 필요하다. LCMV 빔형성 방식은 도달 방향에 대한 왜곡 없는 제약을 쉽게 설정할 수 있고 빔형성 스케일링이 우수하여 전체 랭크를 낮출 수 있다. 본 연구에서는 제안된 QPC(Quadratic Pattern Constraints) 및 LCMV 빔형성 방법을 사용하여 목표물의 정보를 추정한다. 제안 방법은 2차 패턴 구속 조건으로 구속 조건의 수에 따라 원하는 방향으로 빔 패턴 제어를 수행할 수 있다. 시뮬레이션을 통해 제안한 알고리즘으로 원하는 목표물 각도를 추정한다. 추정방향[10° 0° 10°], [-50° -10° 10° 50°], [-50° -10° 0° 10° 50°]에서는 각 목표뮬의 정보를 정확하게 추정하였다. 그러나 목표물[-50° -5° 10° 20°]는 정확하게 추정하지 못했다. 각도 분해능이 10°이상일 때 제안된 알고리즘에 의해서 원하는 목표물이 추정되었지만, 각도 분해능이 10°미만인 경우 원하는 목표물을 정확하게 추정할 수 없었다.

• 한국군사과학기술학회지
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• 제26권1호
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• pp.10-21
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• 2023

For various target tracking applications, it is well known that the Kalman filter is the optimal estimator(in the minimum mean-square sense) to predict and estimate the state(position and/or velocity) of linear dynamical systems driven by Gaussian stochastic noise. In the case of nonlinear systems, Extended Kalman filter(EKF) and/or Unscented Kalman filter(UKF) are widely used, which can be viewed as approximations of the(linear) Kalman filter in the sense of the conditional expectation. However, to implement EKF and UKF, the exact dynamical model information and the statistical information of noise are still required. In this paper, we propose the recurrent neural-network based Kalman filter, where its Kalman gain is obtained via the proposed GRU-LSTM based neural-network framework that does not need the precise model information as well as the noise covariance information. By the proposed neural-network based Kalman filter, the state estimation performance is enhanced in terms of the tracking error, which is verified through various linear and nonlinear tracking problems with incomplete model and statistical covariance information.