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On Bowen Entropy for Stable Sets in Positive Entropy Systems
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作者 ZHANG Zhengwei YAN Kesong ZENG Fanping 《数学进展》 北大核心 2025年第1期99-112,共14页
In this paper,we study the Bowen entropy of stable sets in positive entropy G-system of amenable group actions.The lower bound of the Bowen entropy of these sets are estimated.
关键词 positive entropy stable set Bowen entropy amenable group action
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Weakly Stable Sets of NTU Game
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作者 Han Qiao Hong-Wei Gao 《American Journal of Operations Research》 2012年第1期91-93,共3页
In this paper, the definition of weak dominance is proposed for a NTU game and two new solution concepts of NTU games are introduced: the refined core and weakly stable set. The relationship is explored among the core... In this paper, the definition of weak dominance is proposed for a NTU game and two new solution concepts of NTU games are introduced: the refined core and weakly stable set. The relationship is explored among the core, the weakly stable set and the refined core. 展开更多
关键词 NTU GAME weak DOMINANCE Core weakLY stable set
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Core outcome set for stable angina pectoris in traditional Chinese medicine(COS-SAP-TCM) 被引量:16
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作者 Mingyan Zhang Junhua Zhang +3 位作者 Hui Zi Chua Rui Feng Meijuan Lu Ying Tian 《Acupuncture and Herbal Medicine》 2021年第1期39-48,共10页
Objective:This study aimed to develop a core outcome set(COS)for use in future studies of stable angina pectoris(SAP)in traditional Chinese medicine(TCM).Methods:Systematic literature reviews and qualitative interview... Objective:This study aimed to develop a core outcome set(COS)for use in future studies of stable angina pectoris(SAP)in traditional Chinese medicine(TCM).Methods:Systematic literature reviews and qualitative interviews with cardiologists and patients with SAP treated using TCM were conducted to generate a set of outcomes.Outcomes were prioritized by stakeholders via two rounds of an online Delphi survey and face-to-face consensus meetings.Following the final consensus meeting,a final COS was generated.Results:An initial set of 324 outcomes was identified.A preliminary list of 65 outcomes was employed in the Delphi study.In total,223 participants from seven stakeholder groups were invited to score outcomes in the first Delphi round:87 completed round 1 and 47 completed round 2.Thirty-one participants attended the consensus meeting and agreed on a final core set of outcomes comprising six items across four domains:frequency of angina attack,duration of angina attack,Seattle angina questionnaire,total exercise duration in the exercise treadmill test,cardiovascular events,and QT interval on electrocardiography.Conclusions:The COS developed in this study provides the minimum requirements for measurement and reporting in future TCM clinical trials for the treatment of SAP.The employment of this COS may reduce heterogeneity across trials and facilitate evidencebased decision-making for stakeholders. 展开更多
关键词 Core outcome set Outcome measure stable angina pectoris Traditional Chinese medicine
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ROBUST WEAK ERGODICITY AND STABLE ERGODICITY
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作者 周云华 《Acta Mathematica Scientia》 SCIE CSCD 2013年第5期1375-1381,共7页
In this paper, we define robust weak ergodicity and study the relation between robust weak ergodicity and stable ergodicity for conservative partially hyperbolic systems. We prove that a C^r(r 〉 1) conservative par... In this paper, we define robust weak ergodicity and study the relation between robust weak ergodicity and stable ergodicity for conservative partially hyperbolic systems. We prove that a C^r(r 〉 1) conservative partially hyperbolic diffeomorphism is stably ergodic if it is robustly weakly ergodic and has positive (or negative) central exponents on a positive measure set. Furthermore, if the condition of robust weak ergodicity is replaced by weak ergodicity, then the diffeomophism is an almost stably ergodic system. Additionally, we show in dimension three, a C^r(r 〉 1) conservative partially hyperbolic diffeomorphism can be approximated by stably ergodic systems if it is robustly weakly ergodic and robustly has non-zero central exponents. 展开更多
关键词 weak ergodicity stable ergodieity almost robust ergodicity Lyapunov exponent
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(S,T)-WEAK TRACTABILITY OF MULTIVARIATE LINEAR PROBLEMS IN THE AVERAGE CASE SETTING 被引量:1
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作者 Yongping LIU Guiqiao XU 《Acta Mathematica Scientia》 SCIE CSCD 2019年第4期1033-1052,共20页
The purpose of this article is to investigate (s, t)-weak tractability of multivariate linear problems in the average case set ting. The considered algorithms use finitely many evaluations of arbitrary linear function... The purpose of this article is to investigate (s, t)-weak tractability of multivariate linear problems in the average case set ting. The considered algorithms use finitely many evaluations of arbitrary linear functionals. Generally, we obtained matching necessary and sufficient conditions for (s,t)-weak tractability in terms of the corresponding non-increasing sequence of eigenvalues. Specifically, we discussed (s, t)-weak tractability of linear tensor product problems and obtained necessary and sufficient conditions in terms of the corresponding one-dimensional problem. As an example of applications, we discussed also (s,t)-weak tractability of a multivariate approximation problem. 展开更多
关键词 (s t)-weak TRACTABILITY LINEAR PROBLEM LINEAR tensor product PROBLEM HILBERT space AVERAGE case setting
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Weakly stable constant mean curvature hypersurfaces
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作者 FU Hai-ping XU Hong-wei 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2009年第1期119-126,共8页
Let M^n be an n-dimensional complete noncompact oriented weakly stable constant mean curvature hypersurface in an (n + 1)-dimensional Riemannian manifold N^n+1 whose (n - 1)th Ricci curvature satisfying Ric^N(... Let M^n be an n-dimensional complete noncompact oriented weakly stable constant mean curvature hypersurface in an (n + 1)-dimensional Riemannian manifold N^n+1 whose (n - 1)th Ricci curvature satisfying Ric^N(n-1) (n - 1)c. Denote by H and φ the mean curvature and the trace-free second fundamental form of M respectively. If |φ|^2 - (n- 2)√n(n- 1)|H||φ|+ n(2n - 1)(H^2+ c) 〉 0, then M does not admit nonconstant bounded harmonic functions with finite Dirichlet integral. In particular, if N has bounded geometry and c + H^2 〉 0, then M must have only one end. 展开更多
关键词 constant mean curvature weakly stable hypersurface ENDS
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THE EXISTENCE THEOREM OF THE CONE-WEAK SUBDIFFERENTIAL OF SET-VALUED MAPPING 被引量:1
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作者 HUYUDA MENGZHIQING 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 1998年第4期473-477,共5页
In this paper, the existence theorem of the cone weak subdifferential of set valued mapping in locally convex topological vector space is proved. Received March 30,1998. 1991 MR Subject Classification: 4... In this paper, the existence theorem of the cone weak subdifferential of set valued mapping in locally convex topological vector space is proved. Received March 30,1998. 1991 MR Subject Classification: 47H17,90C29. 展开更多
关键词 set valued mapping cone convex cone weak subgradient cone weak subdifferential.
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A Proposal to Set Up a Stable Supply System for Potassic Fertilizer in China
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作者 CAS Academic Division of Chemistry 《Bulletin of the Chinese Academy of Sciences》 2000年第3期153-157,共5页
Agriculture is an important foundation of China’s socio-economic development. To secure the sound development of modern agriculture in the 21st century, the supply of fertilizers such as potassium is a key factor. Ow... Agriculture is an important foundation of China’s socio-economic development. To secure the sound development of modern agriculture in the 21st century, the supply of fertilizers such as potassium is a key factor. Owing to the limited arable land in China, a vital measure to feed the country’s increasing population is the augmentation of fertilizers so as to gain higher per unit area grain yields. At present, for a fairly long time to come, additional fertilizer resources will mainly come from nitrogen, phosphorus and potassium fertilizers. But there is a severe application disproportion between nitroge- 展开更多
关键词 than more A Proposal to set Up a stable Supply System for Potassic Fertilizer in China
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TH指数为α的LND p- Stable过程的 Salem集(英文)
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作者 钟玉泉 胡迪鹤 《数学杂志》 CSCD 北大核心 2001年第2期121-126,共6页
在本文中 ,我们讨论了指数为 α的 LNDp - Stable过程的象集 ,获得了 Salem集 .也就是说 ,对任意的紧集 E R ,如果 dim E <α ,那么 X(E) a.s.是一个维数为 1 /αdim E的 Salem集 .
关键词 Mβ集 Fourier维数 Salem集 FOURIER变换 LND p-stable过程
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凸多边形等价概率测度集m-stable包的构造
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作者 陈文财 罗攀攀 齐肖阳 《南昌大学学报(理科版)》 CAS 北大核心 2013年第6期519-522,共4页
在一个带Brown流F的概率空间(Ω,FT,P)之下,讨论包含由n个与P等价的概率测度生成的凸包(简称为凸多边形)的最小L1-闭凸的乘积型稳定等价概率测度集(即,m-stable集)的构造问题,证明了一个凸多边形等价概率测度集的m-stable包会包含于M={... 在一个带Brown流F的概率空间(Ω,FT,P)之下,讨论包含由n个与P等价的概率测度生成的凸包(简称为凸多边形)的最小L1-闭凸的乘积型稳定等价概率测度集(即,m-stable集)的构造问题,证明了一个凸多边形等价概率测度集的m-stable包会包含于M={ε(q·W)|q可料,K≤q≤J}在L1的闭包中,其中J,K分别是凸多边形的n个极点所对应的n个可料过程的最大值、最小值可料过程。 展开更多
关键词 等价概率测度 凸多边形 m-stable
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STABLE SUB-GAUSSIAN MODELS CONSTRUCTED BY POISSON PROCESSES 被引量:1
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作者 戴洪帅 李育强 《Acta Mathematica Scientia》 SCIE CSCD 2011年第5期1945-1958,共14页
In this paper, we first prove that one-parameter standard α-stable sub-Gaussian processes can be approximated by processes constructed by integrals based on the Poisson process with random intensity. Then we extend t... In this paper, we first prove that one-parameter standard α-stable sub-Gaussian processes can be approximated by processes constructed by integrals based on the Poisson process with random intensity. Then we extend this result to the two-parameter processes. At last, we consider the approximation of the subordinated fractional Brownian motion. 展开更多
关键词 stable sub-Gaussian process weak convergence Poisson process Riemann integral
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Category of Generalized Intuitionistic Fuzzy Sets 被引量:1
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作者 YANGWan-cai LIXiao-shen 《Chinese Quarterly Journal of Mathematics》 CSCD 北大核心 2005年第2期192-199,共8页
In this paper, category GIFS of generalized intuitionistic fuzzy sets(GIF) is built up. Topoi properties of category GIFS are studied. Firstly, it is proved that the category GIFS has all topoi properties except that ... In this paper, category GIFS of generalized intuitionistic fuzzy sets(GIF) is built up. Topoi properties of category GIFS are studied. Firstly, it is proved that the category GIFS has all topoi properties except that it has no subobject classifiers, Secondly, it is proved that the category GIFS has middle object and consequently GIFS is a weak topos. Thirdly, by the use of theory of weak topos GIFS, the power object of an object in GIFS is studied. 展开更多
关键词 CATEGORY TOPOS middle object weak topos generalized intuitionistic fuzzy set
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Weak thruster fault detection for AUV based on stochastic resonance and wavelet reconstruction 被引量:5
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作者 刘维新 王玉甲 +1 位作者 刘星 张铭钧 《Journal of Central South University》 SCIE EI CAS CSCD 2016年第11期2883-2895,共13页
When the bi-stable stochastic resonance method was applied to enhance weak thruster fault for autonomous underwater vehicle(AUV), the enhancement performance could not satisfy the detection requirement of weak thruste... When the bi-stable stochastic resonance method was applied to enhance weak thruster fault for autonomous underwater vehicle(AUV), the enhancement performance could not satisfy the detection requirement of weak thruster fault. As for this problem, a fault feature enhancement method based on mono-stable stochastic resonance was proposed. In the method, in order to improve the enhancement performance of weak thruster fault feature, the conventional bi-stable potential function was changed to mono-stable potential function which was more suitable for aperiodic signals. Furthermore, when particle swarm optimization was adopted to adjust the parameters of mono-stable stochastic resonance system, the global convergent time would be long. An improved particle swarm optimization method was developed by changing the linear inertial weighted function as nonlinear function with cosine function, so as to reduce the global convergent time. In addition, when the conventional wavelet reconstruction method was adopted to detect the weak thruster fault, undetected fault or false alarm may occur. In order to successfully detect the weak thruster fault, a weak thruster detection method was proposed based on the integration of stochastic resonance and wavelet reconstruction. In the method, the optimal reconstruction scale was determined by comparing wavelet entropies corresponding to each decomposition scale. Finally, pool-experiments were performed on AUV with thruster fault. The effectiveness of the proposed mono-stable stochastic resonance method in enhancing fault feature and reducing the global convergent time was demonstrated in comparison with particle swarm optimization based bi-stochastic resonance method. Furthermore, the effectiveness of the proposed fault detection method was illustrated in comparison with the conventional wavelet reconstruction. 展开更多
关键词 autonomous underwater vehicle(AUV) THRUSTER weak fault particle swarm optimization(PSO) mono-stable stochastic resonance wavelet reconstruction
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Lipid Biomarkers and Their Stable Carbon Isotopes in Ancient Seep Carbonates from SW Taiwan, China
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作者 GUAN Hongxiang XU Lanfang +3 位作者 WANG Qinxian CHEN Duofu WU Nengyou MAO Shengyi 《Acta Geologica Sinica(English Edition)》 CAS CSCD 2019年第1期167-174,共8页
Four massive brecciated, chimney-like, and slender pipe network carbonate samples(JA-4, JA-5, JX-8 and BG-12) were collected from southwestern Taiwan, which were suggested to have formed as a result of anaerobic oxidi... Four massive brecciated, chimney-like, and slender pipe network carbonate samples(JA-4, JA-5, JX-8 and BG-12) were collected from southwestern Taiwan, which were suggested to have formed as a result of anaerobic oxidization of methane(AOM). Considering that the environmental conditions of the carbonates precipitation and the sources of carbon and organic matter need to be further declared, molecular fossils and compound-specific carbon isotopic investigations of the carbonates were conducted in this study. According to lipid biomarkers of 2,6,10,15,19-pentamethyleicosane(PMI) and squalane diagnostic to methanotrophic archaea, as well as the extremely low δ^(13)C values(as low as -1^(13).4‰) detected in samples JA-4, JA-5 and JX-8, these carbonates were revealed to be a result of AOM. Based on the varied δ^(13)C values of characteristic archaea biomarkers in specific samples, biogenic methane was proposed to be responsible for the formation of samples JA-4 and JA-5, whereas a mixed carbon source of ^(13)C-depleted methane and ^(13)C-enriched residual CO_2 from methanogenesis was suggested for the carbonate of JX-8 due to the co-occurrence of a highly positive δ^(13) C_(carb) value(+8‰) and a moderate ^(13)C depletion of PMI. The low content of AOM-related biomarkers and the absence of indicators for ANME-2 suggested that these carbonates were formed in weak seep settings. By comparison, no typical lipid biomarkers for methanotrophic archaea was detected in carbonate BG-12. The short-chain and long-chain n-alkanes accounted for 30% and 45% of all hydrocarbons, respectively, with a CPI value of 1.2, suggesting that the n-alkanes were derived from both marine organisms and terrestrial inputs. A low thermal maturity could be revealed by the incomplete equilibrium value of the C^(31)αβ 22S/(22S+22R) ratio(0.5), and the carbonate BG-12 was probably deposited in a suboxic condition indicated by a value of Pr/Ph ratio(2.5). 展开更多
关键词 METHANE SEEPS lipid biomarkers ANAEROBIC oxidation of METHANE weak SEEP setTINGS
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ON GLOBAL BEHAVIOR OF WEAK SOLUTIONS OF COMPRESSIBLE FLOWS OF NEMATIC LIQUID CRYSTALS
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作者 王伟伟 《Acta Mathematica Scientia》 SCIE CSCD 2015年第3期650-672,共23页
In this article, we investigate the global behavior of weak solutions of a simplified Ericksen-Leslie system for compressible flows of nematic liquid crystals in time in a bounded three-dimension domain-arbitrary forc... In this article, we investigate the global behavior of weak solutions of a simplified Ericksen-Leslie system for compressible flows of nematic liquid crystals in time in a bounded three-dimension domain-arbitrary forces. By adapting the arguments for the compressible Navier-Stokes equations, and carefully analyzing the direction field of liquid crystals in the equations of angular momentum, we show the existence of bounded absorbing sets, global bounded trajectories, and global attractors to weak solutions of compressible flows of nematic liquid crystals with the adiabatic constant γ〉5/3. 展开更多
关键词 Liquid crystals weak solutions bounded absorbing set bounded trajectories ATTRACTOR
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Some Dynamical Properties in Set-valued Discrete Systems 被引量:2
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作者 马先峰 廖公夫 李勇 《Northeastern Mathematical Journal》 CSCD 2005年第1期5-8,共4页
1 Introduction A discrete dynamical system can be expressed as xn+1 ?f(xn), n = 0,1,2,... where X is a metric space and f : X →X is a continuous map. The study of it tells us how the points in the base space X moved.... 1 Introduction A discrete dynamical system can be expressed as xn+1 ?f(xn), n = 0,1,2,... where X is a metric space and f : X →X is a continuous map. The study of it tells us how the points in the base space X moved. Nevertheless, this is not enough for the researches of biological species, demography, numerical simulation and attractors (see [1], [2]). It is necessary to know how the subsets of X moved. In this direction, we consider the set-valued discrete system associated to f, An+1 = (f|-)(An), n = 0,1,2,... where (f|-) is the natural extension of f to K(X) (the class of all compact subsets of X). 展开更多
关键词 set-valued discrete system MINIMALITY topologically weak mixing topo-logical mixing
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Multilayer Multidi mensional Extension Set Theory
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作者 曹少中 杨国为 涂序彦 《Journal of Beijing Institute of Technology》 EI CAS 2006年第2期172-176,共5页
In brder to study the contradiction problem of multilayer multidimensional complex systems, the concepts of extension field and stable field of intersection and union of multilayer multidimensional extension set are g... In brder to study the contradiction problem of multilayer multidimensional complex systems, the concepts of extension field and stable field of intersection and union of multilayer multidimensional extension set are given. Then the related operations and properties are discussed. The results of study expand the concepts of intersection and union of extension set to a general situation, and provide the theoretical basis for production of the concepts of intersection and union of multilayer multidimensional matter element system extension set. In this way, it will be possible that matter element system theory is used to creative designs of complex systems. 展开更多
关键词 multilayer multidimensional extension set extension field stable field
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On Maé Set and Aubry Set
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作者 梁雪 陈翠 《Northeastern Mathematical Journal》 CSCD 2007年第5期433-443,共11页
J. Mather and A. Fathi defined Mané set and Aubry set, which are the important invariant sets in positive definite Lagrangian system, in different ways. They use variational principle and Weak KAM theory respecti... J. Mather and A. Fathi defined Mané set and Aubry set, which are the important invariant sets in positive definite Lagrangian system, in different ways. They use variational principle and Weak KAM theory respectively. In this paper we provide a proof of the equivalence between the two kinds of definitions, and generalize A. Fathi's definition. In the end of the paper, we calculate the Mane set and Aubry set for a single pendulum system. 展开更多
关键词 Mané set Aubry set weak KAM solution Hamilton-Jacobi equation viscosity solution
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Weak Pullback Attractors for Asymptotically Upper Semicompact Nonautonomous Multivalued Semiflow
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作者 李挺 廖公夫 《Northeastern Mathematical Journal》 CSCD 2006年第4期379-382,共4页
1 IntroductionIn this paper we study the existence of pullback attractors for multivalued nonautonomous and multivalued random semiflow. In [1] and [2], the authors have proved the existence of pullback attractors of ... 1 IntroductionIn this paper we study the existence of pullback attractors for multivalued nonautonomous and multivalued random semiflow. In [1] and [2], the authors have proved the existence of pullback attractors of multivalued nonautonomous semiflow (random semiflow) under the assumption of the existence of compact absorbing set. In [3], the authors have proved the existence of pullback attractors of multivalued nonautonomous semiflow and random semiflow under the assumptions of uniformly pullback asymptotically upper semicompact and closed graph. In [4], the authors consider the existence of pullback attractor of singlevalued nonautonomous semiflow and random semiflow under the assumption of pullback asymptotic compactness. Instead of these assumptions, we consider multivalued nonautonomous semiflow and multivalued random semiflow with weak pullback asymptotic upper semi-compactness and prove the existence of pullback attractors. 展开更多
关键词 weak pullback attractor asymptotically upper semicompact absorbing set
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基于SET-CNN的紧凑型地波雷达弱目标检测方法 被引量:4
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作者 李发瑞 纪永刚 +2 位作者 任继红 程啸宇 王心玲 《海洋科学进展》 CAS CSCD 北大核心 2023年第4期753-764,共12页
紧凑型高频地波雷达发射功率较低且采用小孔径阵列,导致雷达回波中的弱目标增多,进而引起基于距离-多普勒谱的目标检测方法性能降低,目标探测能力减弱。为提高紧凑型地波雷达对弱目标的检测性能,本文提出一种基于同步提取变换-卷积神经... 紧凑型高频地波雷达发射功率较低且采用小孔径阵列,导致雷达回波中的弱目标增多,进而引起基于距离-多普勒谱的目标检测方法性能降低,目标探测能力减弱。为提高紧凑型地波雷达对弱目标的检测性能,本文提出一种基于同步提取变换-卷积神经网络(Synchroextracting Transform-Convolutional Neural Network,SET-CNN)的紧凑型地波雷达弱目标检测方法:首先在时频谱处理中,利用信噪比方法抑制信号中的海杂波,减少杂波时频脊线对目标检测的影响;然后基于SET时频谱构建时频脊线样本数据库,再通过卷积神经网络进行时频脊线分类,并基于分类结果的后处理完成船只目标检测。通过仿真和实测数据验证提出的目标检测方法,结果表明,本文提出的方法能够有效检测到弱目标,提高紧凑型地波雷达的目标检测性能。 展开更多
关键词 紧凑型高频地波雷达 同步提取变换-卷积神经网络(set-CNN) 弱目标检测 时频脊线样本数据库
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