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Technology of shipboard two-way microwave time synchronization

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Journal of Beijing Institute of Technology 2014年第4期23卷 511-518页

作者：付永杰李东光刘旭东 Science and Technology on Electormechanical Dynamic Control Laboratory Beijing Institute of Technology unit 92493 of pla Huludao

For the high precision time synchronization demand of ships, advantages and disadvantages of the present time transfer methods are analyzed, the two-way microwave time transfer （TWMTT） method is adopted to resolve the time synchronization problem in the Naval Ship Formation. After expounding the principle and system composition of TWMTT method, the various factors influencing the synchronous precision are analyzed, such as time-interval measurement error, TWMTT equipment delay error, signal propagation error in air, and signal delay error caused by shipping. To improve the time synchronization precision, all the error sources above are deduced with mathematical measures to definite the critical one, and the signal processing measures such as Pseudo code spread spectrum time comparison signal generation technology, FFT fast acquisition technology and precise tracking technology are used into the modem which is the core equipment of the TWMTT. And, calibration method of TWMTT equipment delay are developed. Through theoretical a- nalysis and simulation verification, the precision of shipboard two-way microwave time synchroniza- tion can reach 1 ns.

关键词： two-way microwave time transfer(TWMTT) time synchronization time delay error analysis

A GMDA clustering algorithm based on evidential reasoning architecture

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Chinese Journal of Aeronautics 2024年第1期37卷 300-311页

作者： Haibin WANG Xin GUAN Xiao YI Shuangming LI Guidong SUN Naval Aviation University Yantai 264001China unit 92941 of pla Huludao 125001China Institute of Systems Engineering Beijing 100082China

The traditional clustering algorithm is difficult to deal with the identification and division of uncertain objects distributed in the overlapping region,and aimed at solving this problem,the Evidential Clustering based on General Mixture Decomposition Algorithm(GMDA-EC)is ***,the belief classification of target cluster is carried out,and the sample category of target distribution overlapping region is ***,on the basis of General Mixture Decomposition Algorithm(GMDA)clustering,the fusion model of evidence credibility and evidence relative entropy is constructed to generate the basic probability assignment of the target and achieve the belief division of the ***,the performance of the algorithm is verified by the synthetic dataset and the measured *** experimental results show that the algorithm can reflect the uncertainty of target clustering results more comprehensively than the traditional probabilistic partition clustering algorithm.

关键词： Evidential clustering Credal partition Evidential reasoning Mixed decomposition Gaussian mixture model

QPSO-based algorithm of CSO joint infrared super-resolution and trajectory estimation

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Journal of Systems Engineering and Electronics 2011年第3期22卷 405-411页

作者： Liangkui Lin Hui Xu Dan Xu Wei An Kai Xie School of Electronics and Engineering National University of Defense TechnologyChangsha 410073P.R.China unit 94810 of the pla Nanjing 210007P.R.China Artillery Academy of the pla Hefei 230031P.R.China

The midcourse ballistic closely spaced objects（CSO） create blur pixel-cluster on the space-based infrared focal plane,making the super-resolution of CSO quite necessary.A novel algorithm of CSO joint super-resolution and trajectory estimation is *** algorithm combines the focal plane CSO dynamics and radiation models,proposes a novel least square objective function from the space and time information,where CSO radiant intensity is excluded and initial dynamics（position and velocity） are chosen as the model ***,the quantum-behaved particle swarm optimization（QPSO） is adopted to optimize the objective function to estimate model parameters,and then CSO focal plane trajectories and radiant intensities are ***,the estimated CSO focal plane trajectories from multiple space-based infrared focal planes are associated and filtered to estimate the CSO stereo ballistic ***,the performance（CSO estimation precision of the focal plane coordinates,radiant intensities,and stereo ballistic trajectories,together with the computation load） of the algorithm is tested,and the results show that the algorithm is effective and feasible.

关键词： super-resolution trajectory estimation closely spaced object(CSO) midcourse ballistic infrared focal plane quantumbehaved particle swarm optimization(QPSO).

A super-network equilibrium optimization method for operation architecture with fuzzy demands

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Journal of Systems Engineering and Electronics 2020年第5期31卷 969-982页

作者： XING Qinghua GAO Jiale School of Air Defense and Anti-Missile Air Force Engineering UniversityXi’an 710051China unit 95806 of the pla Beijing 100000China

From the view of information flow, a super-network equilibrium optimization model is proposed to compute the solution of the operation architecture which is made up of a perceptive level, a command level and a firepower level. Firstly, the optimized conditions of the perceptive level, command level and firepower level are analyzed respectively based on the demand of information relation,and then the information supply-and-demand equilibrium model of the operation architecture super-network is established. Secondly,a variational inequality transformation(VIT) model for equilibrium optimization of the operation architecture is given. Thirdly, the contraction projection algorithm for solving the operation architecture super-network equilibrium optimization model with fuzzy demands is designed. Finally, numerical examples are given to prove the validity and rationality of the proposed method, and the influence of fuzzy demands on the super-network equilibrium solution of operation architecture is discussed.

关键词： super-network equilibrium operation architecture fuzzy demand information flow variational inequality transformation

Triggered Asynchronous Cooperative Spectrum Sensing Scheme Based on Dempster-Shafer Theory

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Journal of Donghua University(English Edition) 2013年第6期30卷 477-481页

作者：肖淑艳李世银李宗艳崔洁张晓光 School of Information and Electrical Engineering China University of Mining & Technology unit No.91469 pla

Aiming at solving the problems such as time consuming and application limiting presented in the existing synchronous cooperative spectrum sensing schemes,a triggered asynchronous scheme based on Dempster-Shafer(D-S) theory was *** asynchronously,each cognitive user calculated the confidence measure functions with double threshold spectrum sensing *** the useful report was received by the fusion center,a fusion process would be *** the sensing results were fused together based on D-S *** analysis and simulation results show that the proposed scheme can improve the spectrum sensing efficiency and reduce the calculation amount of the fusion center compared with the existing schemes.

关键词： asynchronous cooperative spectrum sensing ( ACSS ) altered-triggered double threshold Dempster-Shafer (D-S) theory

Association of fluid-attenuated inversion recovery vascular hyperintensity with ischaemic events in internal carotid artery or middle cerebral artery occlusion

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Stroke & Vascular Neurology 2023年第1期8卷 69-76页

作者： Jinhao Lyu Jianxing Hu Xinrui Wang Xiangbing Bian Mengting Wei Liuxian Wang Qi Duan Yina Lan Dekang Zhang Xueyang Wang Tingyang Zhang Chenglin Tian Xin Lou Radiology Chinese PLA General Hospital/Chinese PLA Medical SchoolBeijingChina Radiology Chinese PLA General HospitalBeijingChina Neurology Chinese PLA General HospitalBeijingChina

Background and purpose Individuals with intracranial artery occlusion have high rates of ischaemic events and *** has been challenging to identify patients who had high-risk stroke using a simple,valid and non-invasive screening *** study aimed to investigate whether fluid-attenuated inversion recovery(FLAIR)vascular hyperintensity(FVH),a specific imaging sign on the FLAIR sequence,could be a predictor of ischaemic events in a population with internal carotid artery(ICA)or middle cerebral artery(MCA)*** We retrospectively analysed 147 patients(mean 60.43±12.83 years)with 149 lesions,including 37 asymptomatic and 112 symptomatic cases of ICA or MCA *** occlusion was considered if ischaemic events were present in the relevant territory within 90 *** Alberta Stroke Program Early Computed Tomography Score(FVH-ASPECTS:0-7,with 0 indicating absence of FVH and 7 suggesting prominent FVH)and collateral circulation grade were assessed for each *** logistic regression analysis was performed to detect independent markers associated with symptomatic *** A lower FVH-ASPECTS was associated with a more favourable collateral circulation grade(rho=−0.464,p<0.0001).The FVH-ASPECTS was significantly lower in the asymptomatic occlusion group than in the symptomatic occlusion group(p<0.0001).FVH-ASPECTS(Odd ratio,2.973;95%confidence interval,1.849 to 4.781;p<0.0001)was independently associated with symptomatic status after adjustment for age,sex,lesion location and collateral circulation grade in the multivariate logistic *** area under the curve was 0.861 for the use of FVH-ASPECTS to identify symptomatic *** The ability to discriminate symptomatic from asymptomatic occlusion suggests that FVH may be a predictor of *** a simple imaging sign,FVH may serve as a surrogate for haemodynamic impairments and can be used to identify high-risk stroke cases early in ICA or

关键词： occlusion fluid cerebral

Fluorographene with Narrow Lateral Size and Thickness Distributions Prepared for Enhancing Lubrication Performance of Bentonite Grease

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Journal of Wuhan University of Technology(Materials Science) 2024年第5期39卷 1294-1302页

作者： XIANG Shuo LU Peng ZHANG Qinhui XIAO Bowen YANG Xin ZHANG Peili MA Pengfei HE Yan LI Xuebin Army Logistics Academy of pla Chongqing 401311China Naval Aeronautical University Yantai 2640003China unit 32568 Shaoguan 512131China

Fluorographene(FG)with narrow lateral size and thickness distributions was prepared by a liquid-phase exfoliation method,based on liquid cascade *** Rtec MFT-5000 tribo-meter was used to investigate the lubricating performance of bentonite grease enhanced by the as-prepared *** results showed that the coefficient of friction and the wear volume of bentonite grease with 0.3 wt%FG were decreased by 20.4%and 44.9%,respectively,as compared to those of the base *** main reason is that FG can promote the formation of the tribo-chemical reaction film consisting of complex carbon oxide,Fe_(2)O_(3)and FeF_(3)on the friction surface,which can remarkably improve the performance of friction reduction and prevent the appearance of severe wear.

关键词： fluorographene liquid-phase exfoliation bentonite grease lubrication performance

Method for compensating translational motion of rotationally symmetric target based on local symmetry cancellation

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Journal of Systems Engineering and Electronics 2017年第1期28卷 36-39页

作者： Jingqing Li Sisan He Cunqian Feng Yizhe Wang Air and Missile Defense College Air Force Engineering UniversityXi’an 710051China unit 93764 of the pla Baotou 075000China

The micro-Doppler effect of moving targets may suffer from aliasing and Doppler migration due to the translational motion, which affects the application in real-time target identification. A new compensating method for the rotationally symmetric target is proposed and demonstrated. By utilizing the micro-Doppler symmetry cancellation effect, the method can accurately compensate the translation effect, meanwhile, it behaves well in noise restraint. Computer simulations verify the high accuracy and efficiency of this method.

关键词： target recognition rotationally symmetric micro Doppler translation compensation.

UNIFORMIZATION OF MULTIGRANULAR LINGUISTIC LABELS AND THEIR APPLICATION TO GROUP DECISION MAKING

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Journal of Systems Science and Systems Engineering 2010年第3期19卷 257-276页

作者： Xiaohan YU Zeshui XU Xiumei ZHANG Institute of Communication Engineering PLA University of Science & Technology Institute of Sciences PLA University of Science & Technology

In multiple attribute group decision making （MAGDM） problems based on linguistic information, the granularities of linguistic label sets are usually different due to the differences of thinking modes and habits among decision makers. In order to deal with this inconvenience, the transformation relationships among multigranular linguistic labels （TRMLLs）, which are applied to unify linguistic labels with different granularities into a certain linguistic label set with fixed granularity, are presented in this paper. Furthermore, the reference tables are made according to TRMLLs so that the interrelated calculation will be less complicated, and the method of how to use them is explained in detail. At length, the TRMLLs are illustrated through an application example.

关键词： Multiple attribute group decision making (MAGDM) transformation relationships multigranular linguistic label set