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Sensitivity Analysis of Electromagnetic Scattering from Dielectric Targets with Polynomial Chaos Expansion and Method of Moments
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作者 Yujing Ma Zhongwang Wang +2 位作者 Jieyuan Zhang Ruijin Huo Xiaohui Yuan 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第8期2079-2102,共24页
In this paper,an adaptive polynomial chaos expansion method(PCE)based on the method of moments(MoM)is proposed to construct surrogate models for electromagnetic scattering and further sensitivity analysis.The MoM is a... In this paper,an adaptive polynomial chaos expansion method(PCE)based on the method of moments(MoM)is proposed to construct surrogate models for electromagnetic scattering and further sensitivity analysis.The MoM is applied to accurately solve the electric field integral equation(EFIE)of electromagnetic scattering from homogeneous dielectric targets.Within the bistatic radar cross section(RCS)as the research object,the adaptive PCE algorithm is devoted to selecting the appropriate order to construct the multivariate surrogate model.The corresponding sensitivity results are given by the further derivative operation,which is compared with those of the finite difference method(FDM).Several examples are provided to demonstrate the effectiveness of the proposed algorithm for sensitivity analysis of electromagnetic scattering from homogeneous dielectric targets. 展开更多
关键词 Adaptive polynomial chaos expansion method method of moments radar cross section electromagnetic scattering
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Generalized polynomial chaos expansion by reanalysis using static condensation based on substructuring
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作者 D.LEE S.CHANG J.LEE 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2024年第5期819-836,共18页
This paper presents a new computational method for forward uncertainty quantification(UQ)analyses on large-scale structural systems in the presence of arbitrary and dependent random inputs.The method consists of a gen... This paper presents a new computational method for forward uncertainty quantification(UQ)analyses on large-scale structural systems in the presence of arbitrary and dependent random inputs.The method consists of a generalized polynomial chaos expansion(GPCE)for statistical moment and reliability analyses associated with the stochastic output and a static reanalysis method to generate the input-output data set.In the reanalysis,we employ substructuring for a structure to isolate its local regions that vary due to random inputs.This allows for avoiding repeated computations of invariant substructures while generating the input-output data set.Combining substructuring with static condensation further improves the computational efficiency of the reanalysis without losing accuracy.Consequently,the GPCE with the static reanalysis method can achieve significant computational saving,thus mitigating the curse of dimensionality to some degree for UQ under high-dimensional inputs.The numerical results obtained from a simple structure indicate that the proposed method for UQ produces accurate solutions more efficiently than the GPCE using full finite element analyses(FEAs).We also demonstrate the efficiency and scalability of the proposed method by executing UQ for a large-scale wing-box structure under ten-dimensional(all-dependent)random inputs. 展开更多
关键词 forward uncertainty quantification(UQ) generalized polynomial chaos expansion(GPCE) static reanalysis method static condensation SUBSTRUCTURING
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基于小样本下改进ChaosNet的轴承故障诊断
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作者 李天昊 李志星 王衍学 《组合机床与自动化加工技术》 北大核心 2024年第2期182-185,192,共5页
为解决在训练样本不足条件下,轴承故障特征提取困难的问题,提出一种基于改进神经混沌学习(neurochaos learning+AdaBoost,NL-AdaBoost)的轴承故障诊断新方法。首先,对时域振动信号进行快速傅里叶变换(fast fourier transform,FFT)提取... 为解决在训练样本不足条件下,轴承故障特征提取困难的问题,提出一种基于改进神经混沌学习(neurochaos learning+AdaBoost,NL-AdaBoost)的轴承故障诊断新方法。首先,对时域振动信号进行快速傅里叶变换(fast fourier transform,FFT)提取频域特征,拼接时频域信号获得一维特征样本;其次,输入信号产生对混沌GLS神经元的激励,形成ChaoFEX特征,馈送至集成学习分类器(AdaBoost);随后,选取轴承故障特征样本,对样本集做k折交叉验证,获得模型最优超参数值,将其应用于测试集进行模型分类能力验证;最后,在小样本对比实验中,与4种常见深度学习算法比较模型的macro F1-score。实验结果证明,在低训练样本条件下,NL-AdaBoost模型具有良好的准确性和泛化能力。 展开更多
关键词 小样本训练 神经混沌学习 滚动轴承 故障诊断
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Anti-control of chaos in p Ge photoconductor 被引量:1
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作者 冯玉玲 张喜和 《Chinese Physics B》 SCIE EI CAS CSCD 2009年第12期5212-5218,共7页
We present a scheme for the anti-control of chaos in the p-Ge photoconductor system by using a chaotic laser to irradiate and disturb this system. The numerical simulations show that this scheme can be effectively use... We present a scheme for the anti-control of chaos in the p-Ge photoconductor system by using a chaotic laser to irradiate and disturb this system. The numerical simulations show that this scheme can be effectively used to control periodic states in this t^Ge system into chaotic states. Moreover, the different chaos states with different chaotic orbits can be obtained by appropriately adjusting the disturbance intensity and disturbance frequency, and by increasing this intensity or reducing this frequency, this p-Ge system gradually evolves to fully developed chaotic states. 展开更多
关键词 anti-control of chaos p-Ge photoconductor LASER IRRADIATION
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Period-control and chaos-anti-control of a semiconductor laser using the twisted fiber 被引量:4
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作者 颜森林 《Chinese Physics B》 SCIE EI CAS CSCD 2016年第9期257-263,共7页
A novel semiconductor laser system is presented based on a twisted fiber.To study the period-control and chaos-anticontrol of the laser system,we design a type of optic path as a control setup using the combination of... A novel semiconductor laser system is presented based on a twisted fiber.To study the period-control and chaos-anticontrol of the laser system,we design a type of optic path as a control setup using the combination of the twisted fiber and the polarization controller while we present a physical dynamics model of the delayed dual-feedback laser containing the twisted fiber effect.We give an analysis of the effect of the twisted fiber on the laser.We use the effects of the delayed phase and the rotation angle of the twisted fiber and the characteristics of the system to achieve control of the laser.The laser is deduced to a stable state,a double-periodic state,a period-6 state,a period-8 state,a period-9 state,a multi-period state,beat phenomenon,and so on.The periodic laser can be anti-controlled to chaos.Some chaos-anti-control area is found.The laser system is very useful for the study of chaos-control of the laser setup and the applications of some physics effects. 展开更多
关键词 chaos anti-control laser twisted fiber
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Dynamic modelling and chaos control for a thin plate oscillator using Bubnov–Galerkin integral method
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作者 焦晓东 王新宇 +3 位作者 陶金 孙昊 孙青林 陈增强 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第11期383-391,共9页
The utilization of thin plate systems based on acoustic vibration holds significant importance in micro-nano manipulation and the exploration of nonlinear science. This paper focuses on the analysis of an actual thin ... The utilization of thin plate systems based on acoustic vibration holds significant importance in micro-nano manipulation and the exploration of nonlinear science. This paper focuses on the analysis of an actual thin plate system driven by acoustic wave signals. By combining the mechanical analysis of thin plate microelements with the Bubnov–Galerkin integral method, the governing equation for the forced vibration of a square thin plate is derived. Notably,the reaction force of the thin plate vibration system is defined as f=α|w|, resembling Hooke’s law. The energy function and energy level curve of the system are also analyzed. Subsequently, the amplitude–frequency response function of the thin plate oscillator is solved using the harmonic balance method. Through numerical simulations, the amplitude–frequency curves are analyzed for different vibration modes under the influence of various parameters. Furthermore, the paper demonstrates the occurrence of conservative chaotic motions in the thin plate oscillator using theoretical and numerical methods. Dynamics maps illustrating the system’s states are presented to reveal the evolution laws of the system. By exploring the effects of force fields and system energy, the underlying mechanism of chaos is interpreted. Additionally, the phenomenon of chaos in the oscillator can be controlled through the method of velocity and displacement states feedback, which holds significance for engineering applications. 展开更多
关键词 thin plate oscillator conservative chaos Bubnov-Galerkin method frequency response chaos control
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An incommensurate fractional discrete macroeconomic system:Bifurcation,chaos,and complexity
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作者 Abderrahmane Abbes Adel Ouannas Nabil Shawagfeh 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第3期58-67,共10页
This study proposes a novel fractional discrete-time macroeconomic system with incommensurate order.The dynamical behavior of the proposed macroeconomic model is investigated analytically and numerically.In particular... This study proposes a novel fractional discrete-time macroeconomic system with incommensurate order.The dynamical behavior of the proposed macroeconomic model is investigated analytically and numerically.In particular,the zero equilibrium point stability is investigated to demonstrate that the discrete macroeconomic system exhibits chaotic behavior.Through using bifurcation diagrams,phase attractors,the maximum Lyapunov exponent and the 0–1 test,we verified that chaos exists in the new model with incommensurate fractional orders.Additionally,a complexity analysis is carried out utilizing the approximation entropy(ApEn)and C_(0)complexity to prove that chaos exists.Finally,the main findings of this study are presented using numerical simulations. 展开更多
关键词 chaos macroeconomic system discrete fractional calculus COMPLEXITY
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Intelligent Cybersecurity Classification Using Chaos Game Optimization with Deep Learning Model
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作者 Eatedal Alabdulkreem Saud S.Alotaibi +5 位作者 Mohammad Alamgeer Radwa Marzouk Anwer Mustafa Hilal Abdelwahed Motwakel Abu Sarwar Zamani Mohammed Rizwanullah 《Computer Systems Science & Engineering》 SCIE EI 2023年第4期971-983,共13页
Cyberattack detection has become an important research domain owing to increasing number of cybercrimes in recent years.Both Machine Learning(ML)and Deep Learning(DL)classification models are useful in effective ident... Cyberattack detection has become an important research domain owing to increasing number of cybercrimes in recent years.Both Machine Learning(ML)and Deep Learning(DL)classification models are useful in effective identification and classification of cyberattacks.In addition,the involvement of hyper parameters in DL models has a significantly influence upon the overall performance of the classification models.In this background,the current study develops Intelligent Cybersecurity Classification using Chaos Game Optimization with Deep Learning(ICC-CGODL)Model.The goal of the proposed ICC-CGODL model is to recognize and categorize different kinds of attacks made upon data.Besides,ICC-CGODL model primarily performs min-max normalization process to normalize the data into uniform format.In addition,Bidirectional Gated Recurrent Unit(BiGRU)model is utilized for detection and classification of cyberattacks.Moreover,CGO algorithm is also exploited to adjust the hyper parameters involved in BiGRU model which is the novelty of current work.A wide-range of simulation analysis was conducted on benchmark dataset and the results obtained confirmed the significant performance of ICC-CGODL technique than the recent approaches. 展开更多
关键词 Deep learning chaos game optimization CYBERSECURITY chaos game optimization cyberattack
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A New Multi Chaos-Based Compression Sensing Image Encryption
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作者 Fadia Ali Khan Jameel Ahmed Suliman A.Alsuhibany 《Computers, Materials & Continua》 SCIE EI 2023年第7期437-453,共17页
The advancements in technology have substantially grown the size of image data.Traditional image encryption algorithms have limited capabilities to deal with the emerging challenges in big data,including compression a... The advancements in technology have substantially grown the size of image data.Traditional image encryption algorithms have limited capabilities to deal with the emerging challenges in big data,including compression and noise toleration.An image encryption method that is based on chaotic maps and orthogonal matrix is proposed in this study.The proposed scheme is built on the intriguing characteristics of an orthogonal matrix.Gram Schmidt disperses the values of pixels in a plaintext image by generating a random orthogonal matrix using logistic chaotic map.Following the diffusion process,a block-wise random permutation of the data is performed using multi-chaos.The proposed scheme provides sufficient security and resilience to JPEG compression and channel noise through a series of experiments and security evaluations.It enables Partial Encryption(PE)for faster processing as well as complete encryption for increased security.The higher values of the number of pixels change rates and unified average change intensity confirm the security of the encryption scheme.In contrast to other schemes,the proposed approach can perform full and partial encryption depending on security requirements. 展开更多
关键词 chaos compression image encryption
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基于Swarm卫星数据及CHAOS-6模型的中国地区岩石圈磁场研究
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作者 姜乙 Richard Holme 蒋勇 《Applied Geophysics》 SCIE CSCD 2023年第4期422-431,669,670,共12页
本研究主要关注Swarm卫星数据及CHAOS-6模型对岩石圈磁场的应用。重点考察该模型能否较好地模拟中国地区岩石圈磁场,同时检验高质量的卫星数据中是否还包含模型模拟部分以外的其他信息,特别是岩石圈磁场中的一些小尺度特征,这些信息有... 本研究主要关注Swarm卫星数据及CHAOS-6模型对岩石圈磁场的应用。重点考察该模型能否较好地模拟中国地区岩石圈磁场,同时检验高质量的卫星数据中是否还包含模型模拟部分以外的其他信息,特别是岩石圈磁场中的一些小尺度特征,这些信息有助于研究岩石圈磁场并提高模型的精度。基于Swarm卫星数据和CHAOS-6模型,将卫星数据沿轨道按纬度1^°为间隔网格化后,计算相邻网格的差值,即差分计算。对比不同轨道,不同时间段之间的轨道差分,同时还考虑模型中15-20阶磁场的长期变化,以研究岩石圈磁场中所包含的小尺度成分。结果显示CHAOS-6模型可以很好地模拟Swarm卫星数据,均方偏差在3nT左右,模型基本反映了地磁场的长期变化。此外,从数据上还发现了一个未被模拟的磁异常,该异常位于磁赤道附近,有可能是外源场影响的结果。对于岩石圈磁场的研究应更侧重于所建立的模型而非卫星数据本身。 展开更多
关键词 地磁场 Swarm卫星任务 岩石圈磁场 chaos-6模型
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Critical dispersion of chirped fiber Bragg grating for eliminating time delay signature of distributed feedback laser chaos
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作者 王大铭 雷一航 +1 位作者 史鹏飞 李壮爱 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第9期237-241,共5页
Optical chaos has attracted widespread attention owing to its complex dynamic behaviors.However,the time delay signature(TDS)caused by the external cavity mode reduces the complexity of optical chaos.We propose and nu... Optical chaos has attracted widespread attention owing to its complex dynamic behaviors.However,the time delay signature(TDS)caused by the external cavity mode reduces the complexity of optical chaos.We propose and numerically demonstrate the critical dispersion of chirped fiber Bragg grating(CFBG)for eliminating the TDS of laser chaos in this work.The critical dispersion,as a function of relaxation frequency and bandwidth of the optical spectrum,is found through extensive dynamics simulations.It is shown that the TDS can be eliminated when the dispersion of CFBG is above this critical dispersion.In addition,the influence of dispersive feedback light and output light from a laser is investigated.These results provide important quantitative guidance for designing chaotic semiconductor lasers without TDS. 展开更多
关键词 chaos semiconductor laser time delay signature chirped fiber Bragg grating(CFBG)
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A Color Image Encryption Scheme Based on Singular Values and Chaos
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作者 Adnan Malik Muhammad Ali +2 位作者 Faisal S.Alsubaei Nisar Ahmed Harish Kumar 《Computer Modeling in Engineering & Sciences》 SCIE EI 2023年第10期965-999,共35页
The security of digital images transmitted via the Internet or other public media is of the utmost importance.Image encryption is a method of keeping an image secure while it travels across a non-secure communication ... The security of digital images transmitted via the Internet or other public media is of the utmost importance.Image encryption is a method of keeping an image secure while it travels across a non-secure communication medium where it could be intercepted by unauthorized entities.This study provides an approach to color image encryption that could find practical use in various contexts.The proposed method,which combines four chaotic systems,employs singular value decomposition and a chaotic sequence,making it both secure and compression-friendly.The unified average change intensity,the number of pixels’change rate,information entropy analysis,correlation coefficient analysis,compression friendliness,and security against brute force,statistical analysis and differential attacks are all used to evaluate the algorithm’s performance.Following a thorough investigation of the experimental data,it is concluded that the proposed image encryption approach is secure against a wide range of attacks and provides superior compression friendliness when compared to chaos-based alternatives. 展开更多
关键词 ENCRYPTION image encryption chaos theory color image encryption singular value decomposition compression friendliness
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A novel variable-order fractional chaotic map and its dynamics
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作者 唐周青 贺少波 +3 位作者 王会海 孙克辉 姚昭 吴先明 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第3期281-290,共10页
In recent years,fractional-order chaotic maps have been paid more attention in publications because of the memory effect.This paper presents a novel variable-order fractional sine map(VFSM)based on the discrete fracti... In recent years,fractional-order chaotic maps have been paid more attention in publications because of the memory effect.This paper presents a novel variable-order fractional sine map(VFSM)based on the discrete fractional calculus.Specially,the order is defined as an iterative function that incorporates the current state of the system.By analyzing phase diagrams,time sequences,bifurcations,Lyapunov exponents and fuzzy entropy complexity,the dynamics of the proposed map are investigated comparing with the constant-order fractional sine map.The results reveal that the variable order has a good effect on improving the chaotic performance,and it enlarges the range of available parameter values as well as reduces non-chaotic windows.Multiple coexisting attractors also enrich the dynamics of VFSM and prove its sensitivity to initial values.Moreover,the sequence generated by the proposed map passes the statistical test for pseudorandom number and shows strong robustness to parameter estimation,which proves the potential applications in the field of information security. 展开更多
关键词 chaos fractional difference variable order MULTISTABILITY COMPLEXITY
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Anti-control and Generalized Synchronization of Chaos for a Kind of n-Dimensional Linear Differential System 被引量:2
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作者 ZHANG Xiao-Dan LI Zhi-Ping 《Communications in Theoretical Physics》 SCIE CAS CSCD 2006年第3期461-472,共12页
这篇论文介绍在一个客气的 ofn 维的自治混合系统发现一些混乱引起注意的人,它经由把一些不连续的州的反馈用于客气的 ofn iinear 被认识到微分系统。并且一条建设性的定理为与上述混乱混合系统有关的概括同步被建议。例子为说明方法... 这篇论文介绍在一个客气的 ofn 维的自治混合系统发现一些混乱引起注意的人,它经由把一些不连续的州的反馈用于客气的 ofn iinear 被认识到微分系统。并且一条建设性的定理为与上述混乱混合系统有关的概括同步被建议。例子为说明方法被举。 展开更多
关键词 抵抗控制 混沌理论 状态反馈 同步化
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Quantization of the Kinetic Energy of Deterministic Chaos
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作者 Victor A. Miroshnikov 《American Journal of Computational Mathematics》 2023年第1期1-81,共81页
In previous works, the theoretical and experimental deterministic scalar kinematic structures, the theoretical and experimental deterministic vector kinematic structures, the theoretical and experimental deterministic... In previous works, the theoretical and experimental deterministic scalar kinematic structures, the theoretical and experimental deterministic vector kinematic structures, the theoretical and experimental deterministic scalar dynamic structures, and the theoretical and experimental deterministic vector dynamic structures have been developed to compute the exact solution for deterministic chaos of the exponential pulsons and oscillons that is governed by the nonstationary three-dimensional Navier-Stokes equations. To explore properties of the kinetic energy, rectangular, diagonal, and triangular summations of a matrix of the kinetic energy and general terms of various sums have been used in the current paper to develop quantization of the kinetic energy of deterministic chaos. Nested structures of a cumulative energy pulson, an energy pulson of propagation, an internal energy oscillon, a diagonal energy oscillon, and an external energy oscillon have been established. In turn, the energy pulsons and oscillons include group pulsons of propagation, internal group oscillons, diagonal group oscillons, and external group oscillons. Sequentially, the group pulsons and oscillons contain wave pulsons of propagation, internal wave oscillons, diagonal wave oscillons, and external wave oscillons. Consecutively, the wave pulsons and oscillons are composed of elementary pulsons of propagation, internal elementary oscillons, diagonal elementary oscillons, and external elementary oscillons. Topology, periodicity, and integral properties of the exponential pulsons and oscillons have been studied using the novel method of the inhomogeneous Fourier expansions via eigenfunctions in coordinates and time. Symbolic computations of the exact expansions have been performed using the experimental and theoretical programming in Maple. Results of the symbolic computations have been justified by probe visualizations. 展开更多
关键词 The Navier-Stokes Equations Quantization of Kinetic Energy Deterministic chaos Elementary Pulson of Propagation Internal Elementary Oscillon Diagonal Elementary Oscillon External Elementary Oscillon Wave Pulson of Propagation Internal Wave Oscillon Diagonal Wave Oscillon External Wave Oscillon Group Pulson of Propagation Internal Group Oscillon Diagonal Group Oscillon External Group Oscillon Energy Pulson of Propagation Internal Energy Oscillon Diagonal Energy Oscillon External Energy Oscillon Cumulative Energy Pulson
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Stochastic Chaos of Exponential Oscillons and Pulsons
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作者 Victor A. Miroshnikov 《American Journal of Computational Mathematics》 2023年第4期533-577,共45页
An exact three-dimensional solution for stochastic chaos of I wave groups of M random internal waves governed by the Navier-Stokes equations is developed. The Helmholtz decomposition is used to expand the Dirichlet pr... An exact three-dimensional solution for stochastic chaos of I wave groups of M random internal waves governed by the Navier-Stokes equations is developed. The Helmholtz decomposition is used to expand the Dirichlet problem for the Navier-Stokes equations into the Archimedean, Stokes, and Navier problems. The exact solution is obtained with the help of the method of decomposition in invariant structures. Differential algebra is constructed for six families of random invariant structures: random scalar kinematic structures, time-complementary random scalar kinematic structures, random vector kinematic structures, time-complementary random vector kinematic structures, random scalar dynamic structures, and random vector dynamic structures. Tedious computations are performed using the experimental and theoretical programming in Maple. The random scalar and vector kinematic structures and the time-complementary random scalar and vector kinematic structures are applied to solve the Stokes problem. The random scalar and vector dynamic structures are employed to expand scalar and vector variables of the Navier problem. Potentialization of the Navier field becomes available since vortex forces, which are expressed via the vector potentials of the Helmholtz decomposition, counterbalance each other. On the contrary, potential forces, which are described by the scalar potentials of the Helmholtz decomposition, superimpose to generate the gradient of a dynamic random pressure. Various constituents of the kinetic energy are ascribed to diverse interactions of random, three-dimensional, nonlinear, internal waves with a two-fold topology, which are termed random exponential oscillons and pulsons. Quantization of the kinetic energy of stochastic chaos is developed in terms of wave structures of random elementary oscillons, random elementary pulsons, random internal, diagonal, and external elementary oscillons, random wave pulsons, random internal, diagonal, and external wave oscillons, random group pulsons, random internal, diagonal, and external group oscillons, a random energy pulson, random internal, diagonal, and external energy oscillons, and a random cumulative energy pulson. 展开更多
关键词 The Navier-Stokes Equations Stochastic chaos Helmholtz Decomposition Exact Solution Decomposition into Invariant Structures Experimental and Theoretical Programming Quantization of Kinetic Energy Random Elementary Oscillon Random Elementary Pulson Random Internal Elementary Oscillon Random Diagonal Elementary Oscillon Random External Elementary Oscillon Random Wave Pulson Random Internal Wave Oscillon Random Diagonal Wave Oscillon Random External Wave Oscillon Random Group Pulson Random Internal Group Oscillon Random Diagonal Group Oscillon Random External Group Oscillon Random Energy Pulson Random Internal Energy Oscillon Random Diagonal Energy Oscillon Random External Energy Oscillon Random Cumulative Energy Pulson
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CHAOS-6模型描述的中国地区地磁长期变化及误差分析 被引量:5
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作者 王振东 顾左文 +2 位作者 陈斌 王粲 袁洁浩 《地震研究》 CSCD 北大核心 2017年第3期404-410,共7页
根据CHAOS-6模型,计算了2015年中国地区28个地磁台站的地磁年度变化以及2008.0—2016.5年成都、格尔木、兰州、泰安和通海5个地磁台站的地磁长期变化。分析比较了地磁台站实际观测值与CHAOS-6模型计算值之间的差异,得到两者差值的均值... 根据CHAOS-6模型,计算了2015年中国地区28个地磁台站的地磁年度变化以及2008.0—2016.5年成都、格尔木、兰州、泰安和通海5个地磁台站的地磁长期变化。分析比较了地磁台站实际观测值与CHAOS-6模型计算值之间的差异,得到两者差值的均值及均方误差。结果表明:CHAOS-6模型描述的中国地区地磁长期变化与地磁台站实际观测的地磁长期变化趋势基本一致,但存在一定的差异,28个台站的磁偏角(D)、磁倾角(I)、地磁总强度(F)、北向分量(X)、东向分量(Y)、水平分量(H)、垂直分量(Z)差值的均值和均方误差的平均值分别为-0.9'/1.7',-29.3'/0.8',-116.3 nT/10.2 nT,264.7 nT/13.6 nT,-27.7 nT/15.0 nT,265.2 nT/13.7 nT,-356.9 nT/8.0 nT。因此,在使用CHAOS-6模型研究中国地区区域问题时,应充分考虑模型的误差大小。 展开更多
关键词 chaos模型 地磁年度变化 地磁长期变化 地磁台站
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时空Chaos研究中的CML模型 被引量:4
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作者 黄欣 刘曾荣 谢惠民 《应用数学和力学》 CSCD 北大核心 1993年第10期919-928,共10页
通过对有关差分格式的稳定性分析,我们提出了一类新的格点耦合映射(CML)模型,数值试验表明:我们提出的CML模型是一类有效的研究时空复杂性的模型,特别是对于强耦合系统.
关键词 强耦合 时空 复杂性 格点耦合映射
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基于RS-Chaos-LSSVM的鱼雷航向控制研究
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作者 宋晓茹 宋保维 罗德柱 《弹箭与制导学报》 CSCD 北大核心 2012年第6期41-44,54,共5页
基于典型的非线性系统的鱼雷航向控制存在不确定性因素,尝试提出基于RS-Chaos-LSSVM的航向控制方案。Chaos在线优化LSSVM模型参数,确保控制的精度。为提高控制的实时快速性,采用RS理论消除冗余信息,用约简后的规则集对Chaos-LSSVM模型... 基于典型的非线性系统的鱼雷航向控制存在不确定性因素,尝试提出基于RS-Chaos-LSSVM的航向控制方案。Chaos在线优化LSSVM模型参数,确保控制的精度。为提高控制的实时快速性,采用RS理论消除冗余信息,用约简后的规则集对Chaos-LSSVM模型进行训练控制,满足较好的快速性;RS-Chaos-LSSVM与RS-LSSVM控制器仿真表明,该方法提高了鱼雷航向控制的实时精确性,且对于海流海浪干扰具有良好的自适应抗干扰能力。 展开更多
关键词 控制 粗糙集 LSSVM 混沌优化
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基于RS-Chaos-LSSVM的光电稳瞄系统稳定精度检测方法 被引量:1
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作者 宋晓茹 薛永刚 《西安工业大学学报》 CAS 2013年第10期845-850,共6页
稳定精度是评价光电稳瞄系统性能最为关键的参数之一.针对传统频谱仪测试方法的局限性及测试中干扰因素的不利影响,提出了基于RS-Chaos-LSSVM的光电稳瞄系统稳定精度检测方法.根据光电稳瞄系统测量原理和基本组成,按照RS理论、Chaos和LS... 稳定精度是评价光电稳瞄系统性能最为关键的参数之一.针对传统频谱仪测试方法的局限性及测试中干扰因素的不利影响,提出了基于RS-Chaos-LSSVM的光电稳瞄系统稳定精度检测方法.根据光电稳瞄系统测量原理和基本组成,按照RS理论、Chaos和LSSVM模型,设计了RS-Chaos-LSSVM的光电稳瞄系统稳定精度检测系统.LSSVM把位置稳定环上的陀螺仪反馈的实际转台角度,在以DSP为核心的信号检测处理单元中进行稳定精度检测处理.RS理论可以对进入LSSVM模型样本进行属性值约简,以提高实时快速性.Chaos优化LSSVM模型的参数,旨在提高其控制精度.最后对某机载光电稳瞄系统的定频和随机动态稳定精度分别以RS-LSSVM与RS-Chaos-LSSVM的稳定精度检测进行了测试对比.实验仿真数据表明:利用RS-Chaos-LSSVM检测模型在此稳定精度检测时能够有效剔除干扰数据,比Chaos-LSSVM方法的实时性提高了约50%.因此基于RS-Chaos-LSSVM的稳定精度检测方法,具有更高的可靠性和准确性,达到了期望目标. 展开更多
关键词 粗糙集 最小二乘支持向量机 光电稳瞄 稳定精度 混沌理论
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