• 제목/요약/키워드: the 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.

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.

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.

무기체계 신뢰도 예측시 임무주기 적용 방안에 대한 연구 (Methodologies of Duty Cycle Application in Weapon System Reliability Prediction)

  • 윤희성;정다운;이은학;강태원;이승헌;허만옥
    • 한국신뢰성학회지:신뢰성응용연구
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    • 제11권4호
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    • pp.433-445
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    • 2011
  • Duty cycle is determined as the ratio of operating time to total time. Duty cycle in reliability prediction is one of the significant factors to be considered. In duty cycle application, non-operating time failure rate has been easily ignored even though the failure rate in non-operating period has not been proved to be small enough. Ignorance of non-operating time failure rate can result in over-estimated system reliability calculation. Furthermore, utilization of duty cycle in reliability prediction has not been evaluated in its effectiveness. In order to address these problems, two reliability models, such as MIL-HDBK-217F and RIAC-HDBK-217Plus, were used to analyze non-operating time failure rate. This research has proved that applying duty cycle in 217F model is not reasonable by the quantitative comparison and analysis.

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.

Percutaneous Radiofrequency Ablation Guided by Contrast-enhanced Ultrasound in Treatment of Metastatic Hepatocellular Carcinoma after Liver Transplantation

  • Dai, Xin;Zhao, Hong-Qiang;Liu, Run-Hao;Xu, Chang-Tao;Zheng, Fang;Yu, Li-Bao;Li, Wei-Min
    • Asian Pacific Journal of Cancer Prevention
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    • 제13권8호
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    • pp.3709-3712
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    • 2012
  • This study evaluated the advantages and applications of contrast-enhanced ultrasound (CEUS)-supported percutaneous radiofrequency ablation (RFA) in the treatment of metastatic hepatocellular carcinoma after liver transplantation, based on clinical details. CEUS-supported percutaneous RFA was adopted to treat 12 patients with hepatic metastatic carcinomas after liver transplantation. The diameters of the metastatic carcinomas varied from 1 cm to 5 cm, and the foci were discovered after 3 months to 12 months. Each focus was diagnosed and localised by CEUS for RFA once or twice. Curative effects were evaluated by CEUS or contrast-enhanced CT after the treatment. The re-examination results at 2 weeks post-treatment showed that the foci of 11 patients were ablated completely, whereas one patient with the largest focus required retreatment by RFA because of a partial residue. No local recurrence was found one month later in the re-examination. CEUS-supported percutaneous RFA in the treatment of hepatic metastatic carcinoma after liver transplantation has the advantages of accurate localisation, good efficacy, easy operation, and minimal invasion without any complications. Therefore, it can be recommended as the preferred therapy for hepatic metastatic carcinoma after liver transplantation.

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.

Rapid Detection of Clostridium tetani by Recombinase Polymerase Amplification Using an Exo Probe

  • Guo, Mingjing;Feng, Pan;Zhang, Liqun;Feng, Chunfeng;Fu, Jie;Pu, Xiaoyun;Liu, Fei
    • Journal of Microbiology and Biotechnology
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    • 제32권1호
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    • pp.91-98
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    • 2022
  • Tetanus is a potentially fatal public health illness resulted from the neurotoxins generated by Clostridium tetani. C. tetani is not easily culturable and culturing the relevant bacteria from infected wounds has rarely been useful in diagnosis; PCR-based assays can only be conducted at highly sophisticated laboratories. Therefore, a real-time recombinase polymerase amplification assay (Exo-RPA) was constructed to identify the fragments of the neurotoxin gene of C. tetani. Primers and the exo probe targeting the conserved region were designed, and the resulting amplicons could be detected in less than 20 min, with a detection limit of 20 copies/reaction. The RPA assay displayed good selectivity, and there were no cross-reactions with other infectious bacteria common in penetrating wounds. Tests of target-spiked serum and pus extract revealed that RPA is robust to interfering factors and has great potential for further development for biological sample analysis. This method has been confirmed to be reliable for discriminating between toxic and nontoxic C. tetani strains. The RPA assay dramatically improves the diagnostic efficacy with simplified device architecture and is a promising alternative to real-time PCR for tetanus detection.

Application of cost-sensitive LSTM in water level prediction for nuclear reactor pressurizer

  • Zhang, Jin;Wang, Xiaolong;Zhao, Cheng;Bai, Wei;Shen, Jun;Li, Yang;Pan, Zhisong;Duan, Yexin
    • Nuclear Engineering and Technology
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    • 제52권7호
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    • pp.1429-1435
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    • 2020
  • Applying an accurate parametric prediction model to identify abnormal or false pressurizer water levels (PWLs) is critical to the safe operation of marine pressurized water reactors (PWRs). Recently, deep-learning-based models have proved to be a powerful feature extractor to perform high-accuracy prediction. However, the effectiveness of models still suffers from two issues in PWL prediction: the correlations shifting over time between PWL and other feature parameters, and the example imbalance between fluctuation examples (minority) and stable examples (majority). To address these problems, we propose a cost-sensitive mechanism to facilitate the model to learn the feature representation of later examples and fluctuation examples. By weighting the standard mean square error loss with a cost-sensitive factor, we develop a Cost-Sensitive Long Short-Term Memory (CSLSTM) model to predict the PWL of PWRs. The overall performance of the CSLSTM is assessed by a variety of evaluation metrics with the experimental data collected from a marine PWR simulator. The comparisons with the Long Short-Term Memory (LSTM) model and the Support Vector Regression (SVR) model demonstrate the effectiveness of the CSLSTM.