• 제목/요약/키워드: Defense Science and Technology

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Analysis of Deception Jamming Effects on FM Radio based Passive Radar (FM 라디오 기반 수동형 레이다 기만재밍 효과 분석)

  • Song, Kyuha;Kwak, Hyungyu;Kim, Sanhae;Jeong, Inhwan;Lee, Jonghwan;Lee, Byeongnam
    • Journal of the Korea Institute of Military Science and Technology
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    • v.25 no.3
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    • pp.239-250
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    • 2022
  • In this paper, we analyze the performance of an FM radio based passive radar in the presence of deception jamming such as false-target generation. To do this, we examine the effects of applying the deception jamming signal to the passive radar through the derivation of the construction of the amplitude-range-Doppler(ARD) plot. The analysis results show that applying the deception jamming signal with the low power similar to the target echo signal generates false targets at positions set by the jamming variables compared to the real target position in the ARD plot. Also, it is possible to induce the jamming effect so that only false targets are detected by selecting appropriate jamming power. Simulations are included to verify the theoretical results and to discuss on the effectiveness of the deception jamming on the FM radio based passive radar.

Development of Unmanned Aerial Vehicle System Integration Laboratory(UAV SIL) for the Integrated Verification (무인항공기 체계의 통합검증을 위한 무인항공기 체계통합실험실(UAV SIL) 개발)

  • Jae Ick Shim;Hee Chae Woo;Sang Jin Kim;Sang Jun Jung
    • Journal of the Korea Institute of Military Science and Technology
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    • v.27 no.1
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    • pp.70-79
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    • 2024
  • This paper describes the results of the development of the the unmanned aerial vehicle system integration laboratory(UAV SIL) for the integrated verification. This UAV SIL is designed to test the robustness of the UAV system including the operational logics and the flight control system behaviors under many abnormal and emergency conditions such as data-link losses, airborne subsystem failures, engine shut down conditions, and ground control station faults. This paper presents how to build the UAV SIL and how to verify the in-development UAV system through the UAV SIL.

Current Status of DTAQ Information Technology Architecture and Trends of Enterprise Architecture Tools (국방기술품질원 정보기술 아키텍처 구축 현황 및 엔터프라이즈 아키텍처 제품 동향)

  • Lee, Ho-Gyun;Kim, Jung-Soo;Kim, Jae-Woo;Lee, Young-Sun
    • Proceedings of the Korean Information Science Society Conference
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    • 2008.06b
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    • pp.91-95
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    • 2008
  • 2005년 MND-AF v1.0의 제정으로 시작된 국방 아키텍처 활동은 2007년 범 정부 아키텍처 프레임워크와의 산출물 연계를 위한 v1.2 발표와 함께 새로운 전기를 맞고 있다. 본 논문에서는 국방 아키텍처 활동 소개와 국방 아키텍처 변화에 따른 국방기술품질원의 자체 아키텍팅 활동 정리 그리고 v1.2의 도입과 함께 최근 관심 사항이 되고 있는 ITA/EA 툴의 제품 동향과 도입 사업 추진 시의 평가기준 등을 제시한다.

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Static Ejection Test for Separation Analysis of 2,000lb-Class Store (2,000lb급 장착물의 분리분석을 위한 지상투하시험)

  • Byungjoon Shin;Young-hee Jo;Min-soo Kim
    • Journal of the Korea Institute of Military Science and Technology
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    • v.26 no.4
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    • pp.344-351
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    • 2023
  • Static ejection tests were conducted using the 2,000lb-Class Store to provide ejector model for the store separation simulation. In this study, static ejection test device for 2,000lb-class store was constructed and reaction force applied to store was measured over time. In addition, the trajectories of the ejected store were obtained using photogrammetry and compared with the simulations using developed ejector model. The results of the static ejection test were analyzed to determine the cartridge-orifice combination to be used for store separation. Flight tests were performed by applying the analysis results and verified that the store was safely separated from the aircraft.

Second Order Impulsive Neutral Functional Differential Inclusions

  • Liu, Yicheng;Li, Zhixiang
    • Kyungpook Mathematical Journal
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    • v.48 no.1
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    • pp.1-14
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    • 2008
  • In this paper, we investigate the existence of solutions of second order impulsive neutral functional differential inclusions which the nonlinearity F admits convex and non-convex values. Some results under weaker conditions are presented. Our results extend previous ones. The methods rely on a fixed point theorem for condensing multivalued maps and Schaefer's fixed point theorem combined with lower semi-continuous multivalued operators with decomposable values.

Research of Considerations for Effective Operation of Weapons Data Link (무장데이터링크의 효과적인 운용을 위한 고려사항 고찰)

  • Woo, Sang Hyo;Baek, Inhye;Kwon, Ki-Jeong;Kim, Ki Bum
    • Journal of the Korea Institute of Military Science and Technology
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    • v.21 no.6
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    • pp.886-893
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    • 2018
  • U.S. and the allies attacked chemical weapons sites in Syria in 2018, and verbal battles are carried out about the effectiveness of the air strike. Syria claimed 13 missiles were shot down, and Russia claimed 71 missiles were shot down while the U.S. released pictures of completely destroyed targets, only. It led controversy about the effectiveness of missile defense system. If there is a method to observe mission success rate of the air strike, it can not only improve combat awareness but also can be a good sales strategy in military industry. This paper describes effects and considerations of a Weapon Data Link(WDL) technology which can be used as a smoking gun of effectiveness. The paper describes WDL abilities such as In-Flight Track Update, Loiter, and Bomb Hit Indication etc., and presents examples of expected effectiveness of the WDL. In addition, this paper briefly summarizes operational consideration for better performance.

Analysis of Acceleration Characteristics of a Railgun (레일건 가속특성 분석)

  • Lee, Young-Hyun;Kim, Seong-Ho;Lee, Byung-Ha
    • Journal of the Korea Institute of Military Science and Technology
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    • v.24 no.5
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    • pp.511-518
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    • 2021
  • To accelerate a launch mass with a low level of pressure as possible in a railgun, it is required to hold supplied current nearly constant during launch phase. We obtained the discharging conditions for required current shaping by modeling and analysis of circuit equations coupled to acceleration equation of the launch mass. The acceleration characteristics of the railgun in the conditions were analyzed by comparing experimental and theoretical results.

Analysis of Trends for Weapon System Accidents Using Social Network Analysis (사회 연결망 분석을 활용한 무기체계 안전사고 동향 분석)

  • Kang, Eonbi;Park, Sanghyun;Kwon, Kiseok;Jeon, Jeonghwan
    • Journal of the Korea Institute of Military Science and Technology
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    • v.25 no.1
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    • pp.82-95
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    • 2022
  • Since military weapon accidents or breakdowns are directly linked to enormous damage, it is important to analyze the causes of weapons system accidents. Recently, in the defense sector, there have been cases in which budget has been saved through analysis of the causes of frequent breakdowns and improvement activities that have occurred in the process of operating weapon systems since 2015. But due to the nature of the defense sector, it is not easy to collect data and studies on weapons system accidents have been insufficient so far. Therefore, this study aims to investigate the causes and types of military weapon accidents by collecting military weapon accident data for military weapon systems and analyzing trends by weapon system classification through the analysis process. It analyzes statistically and visually through social network analysis, NodeXL. It is expected that this study will help improve the stability of the weapon system by reducing the number of military weapon accidents and failures.

Light/Dark Responsiveness of Kinetin-Inducible Secondary Metabolites and Stress Proteins in Rice Leaf

  • Cho, Kyoung-Won;Kim, Dea-Wook;Jung, Young-Ho;Shibato, Junko;Tamogami, Shigeru;Yonekura, Masami;Jwa, Nam-Soo;Kubo, Akihiro;Agrawal, Ganesh Kumar;Rakwal, Randeep
    • Journal of Crop Science and Biotechnology
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    • v.10 no.2
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    • pp.112-116
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    • 2007
  • Kinetin(KN) is an inducer of rice(Oryza sativa L.) defense/stress responses, as evidenced by the induction of inducible secondary metabolite and defense/stress protein markers in leaf. We show a novel light-dependent effect of KN-triggered defense stress responses in rice leaf. Leaf segments treated with KN(100 ${\mu}M$) show hypersensitive-like necrotic lesion formation only under continuous light illumination. Potent accumulation of two phytoalexins, sakuranetin and momilactone A(MoA) by KN that peaks at 48 h after treatment under continuous light is completely suppressed by incubation under continuous dark. Using two-dimensional gel electrophoresis we identified KN-induced changes in ribulose-1, 5-bisphosphate carboxylase/oxygenase, energy- and pathogenesis-related proteins(OsPR class 5 and 10 members) by N-terminal amino acid sequencing and mass spectrometry. These changes were light-inducible and could not be observed in the dark(and control). Present results provide a new dimension(light modulation/regulation) to our finding that KN has a potential role in the rice plant self-defense mechanism.

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The influence of load pulse shape on pressure-impulse diagrams of one-way RC slabs

  • Wang, Wei;Zhang, Duo;Lu, Fangyun
    • Structural Engineering and Mechanics
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    • v.42 no.3
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    • pp.363-381
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    • 2012
  • This study is aimed at providing an efficient analytical model to obtain pressure- impulse diagram of one-way reinforced concrete slabs subjected to different shapes of air blast loading using single degree of freedom method (SDOF). A tri-linear elastic perfectly plastic SDOF model has been used to obtain the pressure-impulse diagram to correlate the blast pressure and the corresponding concrete flexural damage. In order to capture the response history for the slab, a new approximately SDOF method based on the conventional SDOF method is proposed and validated using published test data. The influences of pulse loading shape on the pressure-impulse diagram are studied. Based on the results, a pressure-impulse diagram generation method using SDOF and an analytical equation for the pressure-impulse diagram is proposed to different damage levels and different blast loading shapes.