• 제목/요약/키워드: Army

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Joint FrFT-FFT basis compressed sensing and adaptive iterative optimization for countering suppressive jamming

  • Zhao, Yang;Shang, Chaoxuan;Han, Zhuangzhi;Yin, Yuanwei;Han, Ning;Xie, Hui
    • ETRI Journal
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    • 제41권3호
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    • pp.316-325
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    • 2019
  • Accurate suppressive jamming is a prominent problem faced by radar equipment. It is difficult to solve signal detection problems for extremely low signal to noise ratios using traditional signal processing methods. In this study, a joint sensing dictionary based compressed sensing and adaptive iterative optimization algorithm is proposed to counter suppressive jamming in information domain. Prior information of the linear frequency modulation (LFM) and suppressive jamming signals are fully used by constructing a joint sensing dictionary. The jamming sensing dictionary is further adaptively optimized to perfectly match actual jamming signals. Finally, through the precise reconstruction of the jamming signal, high detection precision of the original LFM signal is realized. The construction of sensing dictionary adopts the Pei type fast fractional Fourier decomposition method, which serves as an efficient basis for the LFM signal. The proposed adaptive iterative optimization algorithm can solve grid mismatch problems brought on by undetermined signals and quickly achieve higher detection precision. The simulation results clearly show the effectiveness of the method.

사이버 위협 대응을 위한 군(軍) 정보화자산관리시스템과 연계한 군(軍) 취약점 관리 방안 (Military Vulnerability Management Plan based on Military IT Asset Management System for Cyber Threat Response)

  • 김종화;임재성
    • 융합보안논문지
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    • 제18권1호
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    • pp.111-116
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    • 2018
  • 우리 군(軍)의 사이버 공간은 적으로부터 지속적인 위협을 받고 있다. 이 같은 사이버 위협에 대응하기 위해 군(軍) 정보화 자산에 대한 취약점을 조기에 식별하고 제거하여야 한다. 그러나 현재 우리 군(軍)은 취약점에 대한 체계적인 관리가 미흡한 실정이다. 따라서 본 논문에서는 취약점 관리에 대한 각 국의 동향과 군(軍) 취약점 관리 실태를 조사하고, 이를 바탕으로 군(軍) 정보화 자산에 대한 효율적인 취약점 관리를 위해 취약점 데이터베이스와 군(軍) 정보화자산관리시스템을 연계 구축하는 방안을 제시하였다.

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AHP 기법을 이용한 Army TIGER 부대 공격용 드론의 작전요구성능 선정에 관한 기초 연구 (A Basic Study on the Selection of Required Operational Capability for Attack Drones of Army TIGER Units Using AHP Technique)

  • 이진호;권성진
    • 한국군사과학기술학회지
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    • 제26권2호
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    • pp.197-204
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    • 2023
  • The importance of each warfighting function for Army TIGER unit attack drones is measured using the AHP technique. As a result, the importance of attack drones is high in the order of maneuver, firepower, intelligence, command/control, protection, and operation sustainment, but the importance of maneuver, firepower, and intelligence are almost similar. In addition, it is analyzed that attack drones capable of carrying out day and night missions by being equipped with an EO/IR sensor and being commanded/controlled in conjunction with the C4I system to eliminate threats with small bombs or aircraft collisions is needed. Finally, based on the results of this study, a virtual battle scenario for attack drones is proposed.

Exploring Extreme Events(X-event) in the High-Tech Science & Technology Field

  • Sang-Keun Cho;Jong-Hoon Kim;Eui-Chul Shin;Myung-Sook Hong;Jun-Chul Song;Sang-Hyuk Park
    • International Journal of Advanced Culture Technology
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    • 제11권2호
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    • pp.191-195
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    • 2023
  • An X-event is an event that is difficult to predict and unlikely to occur, but if it occurs, it has a very large ripple effect, such as loss of life, property, territory, and emotional turmoil. Extreme events are unlikely to occur, but they can happen someday, and if they do, they have a great impact on society as a whole, so they must be prepared to minimize the impact and impact. For this purpose, we collected opinions from low-level experts at the Korea Army Research Center for Future & Innovation and the Army College on extreme events that can trigger the near future (10 years) in the field of high-tech science and technology, which is currently developing rapidly after the 4th Industrial Revolution. The researchers intend to synthesize and analyze this data to derive implications and provide a response direction to alleviate the ultra-uncertainty of extreme events and provide a cornerstone for crisis management strategies for the occurrence of serial and simultaneous extreme events.

Research on the Applicability of Target-detection Methods for Land-based Hyperspectral Imaging

  • Qianghui Wang;Bing Zhou;Wenshen Hua;Jiaju Ying;Xun Liu;Lei Deng
    • Current Optics and Photonics
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    • 제8권3호
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    • pp.282-299
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    • 2024
  • Target detection (TD) is a research hotspot in the field of hyperspectral imaging (HSI). Traditional TD methods often mine targets from HSIs under a single imaging condition, without considering the influence of imaging conditions. In fact, the spectra of ground objects in HSIs are uncertain and affected by the imaging conditions (weather, atmospheric, light, time, and other angle conditions including zenith angle). Hyperspectral data changes under different imaging conditions. Therefore, the detection result for a single imaging condition cannot accurately reflect the effectiveness of the detection method used. It is necessary to analyze the performance of various detection methods under different imaging conditions, to find a more applicable detection method. In this paper, we study the performance of TD methods under various land-based imaging conditions. We first summarize classical TD methods and evaluation methods. Then, the detection effects under various imaging conditions are analyzed. Finally, the concepts of the stability coefficient (SC) and effective area under the curve (EAUC) are proposed to comprehensively evaluate the applicability of detection methods under land-based imaging conditions, in terms of both detection accuracy and stability. This is conducive to our selection of detection methods with better applicability in land-based contexts, to improve detection accuracy and stability.

임진왜란시기 합천지역의 의병 활동과 전투 (Military Activity and Combat in Hapcheon Area during the Imjin Invasion Period)

  • 곽낙현
    • 동양고전연구
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    • 제70호
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    • pp.257-301
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    • 2018
  • 이 연구의 목적은 임진왜란 시기 합천지역의 의병활동과 합천지역의 전투를 조명하는 것이다. 이에 대한 결론은 다음과 같다. 첫째, 정인홍은 합천, 김면은 고령에서 의병 창의를 하게 되었다. 정인홍은 지피지기의 리더십을, 김면은 조화의 리더십을 발휘하여 의병을 이끌고 일본군에 대항하였다. 둘째, 정인홍 의병군의 전투는 1차 무계전투, 사원동 복병전투, 초계 마진전투, 안언전투, 3차 성주성전투이다. 김면 의병군의 전투는 연강전투, 개산포전투, 2차 무계전투, 우척현전투, 지례전투, 사랑암전투이다. 정인홍 김면이 연합하여 싸운 전투는 1차 성주성전투, 2차 성주성전투이었다. 정유재란시기 정인홍은 경상우도의 군량을 책임지는 조도사의 역할을 수행하였다. 아울러 합천지역은 일본군이 전라도로 들어가는 진입로이자 수송로였다. 셋째, 명군의 참전과 역할은 일본군을 조선에서 몰아내고 요동을 방어하는 이이제이의 전술과 함께 일본군을 대항하는 견제 장치의 한방편이었다. 1593년(선조 26) 1월 이여송의 평양성 전투 승전 이후, 명군은 적극적인 전투보다는 강화협상을 통한 실리를 추구하였다. 실제적으로 진주성전투가 벌어졌을 때, 명군의 유정 부대는 1593년 6월 말에 사천병의 단병무예를 가지고 입성하였으나, 경략 송응창과 제독 이여송의 명령을 기다려야 한다는 이유로 참여하지 않았다. 넷째, 임진왜란 시기 조선은 일본군의 침략과 명군의 군량미 원조 등 전국토가 폐허로 참담한 피해를 입었지만, 각 지역의 의병과 관군이 협력하여 일본군을 물리쳤다. 경상우도 합천지역의 사례를 통해 파악할 수 있었다. 특히 조선은 전쟁기간 중에 일본과의 강화와 전투의 두 가지 측면에서 전권을 행사하였던 명군의 압력에 굴복하지 않고, 주체성을 내세워 일본군과 끝까지 싸우겠다는 항전의지를 보임으로써 민족적 자신감과 긍지를 잃지 않았다. 이러한 정신문화는 향보와 근왕의식에서 비롯되었으며, 외세의 침략으로부터 나라를 지키고자 했던 지역공동체의 하나 된 마음과 정신이 승화된 민족의 저항정신이었다.

Association Between TP53 Arg72Pro Polymorphism and Hepatocellular Carcinoma Risk: A Meta-analysis

  • Xu, Chang-Tao;Zheng, Fang;Dai, Xin;Du, Ji-Dong;Liu, Hao-Run;Zhao, Li;Li, Wei-Min
    • Asian Pacific Journal of Cancer Prevention
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    • 제13권9호
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    • pp.4305-4309
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    • 2012
  • Background: Previous studies on the association between the TP53 Arg72Pro polymorphism and hepatocellular carcinoma (HCC) risk obtained controversial findings. This study aimed to quantify the strength of the association by meta-analysis. Methods: We searched PubMed and Wangfang databases for published studies on the association between the TP53 Arg72Pro polymorphism and HCC risk, using the pooled odds ratio (OR) with its 95% confidence intervals (95% CI) for assessment. Results: 10 studies with a total of 2,026 cases and 2,733 controls were finally included into this meta-analysis. Overall, the TP53 Arg72Pro polymorphism was not associated with HCC risk (all P values greaterth HCC risk in Caucasians in three genetic models (For Pro versus Arg, OR = 1.20, 95%CI 1.03-1.41; For ProPro versus ArgArg, OR = 1.74, 95%CI 1.23-2.47; For ProPro versus ArgPro/ArgArg, OR = 1.85, 95%CI 1.33-2.57). However, there was no significant association between the TP53 Arg72Pro polymorphism and HCC risk in East Asians (all P values greater than 0.10). No evidence of publication bias was observed. Conclusion: Meta-analyses of available data suggest an obvious association between the TP53 Arg72Pro and HCC risk in Caucasians. However, the TP53 Arg72Pro polymorphism may have a race-specific effect on HCC risk and further studies are needed to elucidate this possible effect.

Sand particle-Induced deterioration of thermal barrier coatings on gas turbine blades

  • Murugan, Muthuvel;Ghoshal, Anindya;Walock, Michael J.;Barnett, Blake B.;Pepi, Marc S.;Kerner, Kevin A.
    • Advances in aircraft and spacecraft science
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    • 제4권1호
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    • pp.37-52
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    • 2017
  • Gas turbines operating in dusty or sandy environment polluted with micron-sized solid particles are highly prone to blade surface erosion damage in compressor stages and molten sand attack in the hot-sections of turbine stages. Commercial/Military fixed-wing aircraft engines and helicopter engines often have to operate over sandy terrains in the middle eastern countries or in volcanic zones; on the other hand gas turbines in marine applications are subjected to salt spray, while the coal-burning industrial power generation turbines are subjected to fly-ash. The presence of solid particles in the working fluid medium has an adverse effect on the durability of these engines as well as performance. Typical turbine blade damages include blade coating wear, sand glazing, Calcia-Magnesia-Alumina-Silicate (CMAS) attack, oxidation, plugged cooling holes, all of which can cause rapid performance deterioration including loss of aircraft. The focus of this research work is to simulate particle-surface kinetic interaction on typical turbomachinery material targets using non-linear dynamic impact analysis. The objective of this research is to understand the interfacial kinetic behaviors that can provide insights into the physics of particle interactions and to enable leap ahead technologies in material choices and to develop sand-phobic thermal barrier coatings for turbine blades. This paper outlines the research efforts at the U.S Army Research Laboratory to come up with novel turbine blade multifunctional protective coatings that are sand-phobic, sand impact wear resistant, as well as have very low thermal conductivity for improved performance of future gas turbine engines. The research scope includes development of protective coatings for both nickel-based super alloys and ceramic matrix composites.

국군 수도병원의 심혈관계 수술 304예에 대한 임상적 고찰 (Clinical Analysis of Cardiovascular Operations in Korean Army Forces Capital Hospital - 304 Cases -)

  • 선경;박영환;김범식;이건우;이영욱;백광제;정원상;곽영태;김형묵
    • Journal of Chest Surgery
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    • 제21권6호
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    • pp.1040-1051
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    • 1988
  • From 1959 through Jun. 1988, 2094 cases of various Cardiovascular diseases were operated, which were consisted of 1215 open heart surgery under extra-corporeal circulation or hypothermia and 879 conventional Cardiovascular Surgery at Department of Thoracic & Cardiovascular Surgery in National Medical Center. There were 1111 congenital heart anomalies and 983 acquired cardiovascular diseases. Among 1111 congenital cases, acyanotic cases were 748 and cyanotic cases were 363. In acquired heart cases, valvular heart diseases [702 cases] were the most frequent and a small No. of cardiac tumor and coronary artery diseases were included. Overall operative mortality was 9.3%, consisting of 4.6% for acyanotic anomaly, 20.6% for cyanotic anomaly and 8.7% for acquired heart diseases. In open heart surgery, overall mortality was 11.6% and 6% in conventional cardiovascular surgery.

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The Nedd8-activating enzyme inhibitor MLN4924 suppresses colon cancer cell growth via triggering autophagy

  • Lv, Yongzhu;Li, Bing;Han, Kunna;Xiao, Yang;Yu, Xianjun;Ma, Yong;Jiao, Zhan;Gao, Jianjun
    • The Korean Journal of Physiology and Pharmacology
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    • 제22권6호
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    • pp.617-625
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    • 2018
  • Neddylation is a post-translational protein modification process. MLN4924 is a newly discovered pharmaceutical neddylation inhibitor that suppresses cancer growth with several cancer types. In our study, we first investigated the effect of MLN4924 on colon cancer cells (HCT116 and HT29). MLN4924 significantly inhibited the neddylation of cullin-1 and colon cancer cell growth in a time and dose-dependent manner. MLN4924 induced G2/M cell cycle arrest and apoptosis in HCT116 and HT29 cells. Moreover, MLN4924 also triggered autophagy in HCT116 and HT29 cells via suppressing the PI3K/AKT/mTOR pathway. Inhibiting autophagy by autophagy inhibitor 3-MA or ATG5 knockdown reversed the function of MLN4924 in suppressing colon cancer cell growth and cell death. Interestingly, MLN4924 suppresses colon cell growth in a xenograft model. Together, our finding revealed that blocking neddylation is an attractive colon cancer therapy strategy, and autophagy might act as a novel anti-cancer mechanism for the treatment of colon cancer by MLN4924.