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An improved efficient adaptive method for large-scale multiexplosives explosion simulations
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作者 Tao Li Cheng Wang Baojun Shi 《Defence Technology(防务技术)》 2025年第3期28-47,共20页
Shock wave caused by a sudden release of high-energy,such as explosion and blast,usually affects a significant range of areas.The utilization of a uniform fine mesh to capture sharp shock wave and to obtain precise re... Shock wave caused by a sudden release of high-energy,such as explosion and blast,usually affects a significant range of areas.The utilization of a uniform fine mesh to capture sharp shock wave and to obtain precise results is inefficient in terms of computational resource.This is particularly evident when large-scale fluid field simulations are conducted with significant differences in computational domain size.In this work,a variable-domain-size adaptive mesh enlargement(vAME)method is developed based on the proposed adaptive mesh enlargement(AME)method for modeling multi-explosives explosion problems.The vAME method reduces the division of numerous empty areas or unnecessary computational domains by adaptively suspending enlargement operation in one or two directions,rather than in all directions as in AME method.A series of numerical tests via AME and vAME with varying nonintegral enlargement ratios and different mesh numbers are simulated to verify the efficiency and order of accuracy.An estimate of speedup ratio is analyzed for further efficiency comparison.Several large-scale near-ground explosion experiments with single/multiple explosives are performed to analyze the shock wave superposition formed by the incident wave,reflected wave,and Mach wave.Additionally,the vAME method is employed to validate the accuracy,as well as to investigate the performance of the fluid field and shock wave propagation,considering explosive quantities ranging from 1 to 5 while maintaining a constant total mass.The results show a satisfactory correlation between the overpressure versus time curves for experiments and numerical simulations.The vAME method yields a competitive efficiency,increasing the computational speed to 3.0 and approximately 120,000 times in comparison to AME and the fully fine mesh method,respectively.It indicates that the vAME method reduces the computational cost with minimal impact on the results for such large-scale high-energy release problems with significant differences in computational domain size. 展开更多
关键词 Large-scale explosion Shock wave adaptive method Fluid field simulations Efficient method
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基于Power Extrapolation和Adaptive Method的网页评估新算法 被引量:2
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作者 刘惠义 董志勇 《计算机工程与应用》 CSCD 北大核心 2006年第15期66-68,74,共4页
Google的PageRank算法通过对超链接结构的分析,有效地提高了搜索结果的排序质量。PowerExtrapolation算法通过特征值直接求解马尔可夫超链接矩阵的主特征向量,但该算法的迭代次数与参数d的选择密切相关,而参数d的确定目前无明显规律可... Google的PageRank算法通过对超链接结构的分析,有效地提高了搜索结果的排序质量。PowerExtrapolation算法通过特征值直接求解马尔可夫超链接矩阵的主特征向量,但该算法的迭代次数与参数d的选择密切相关,而参数d的确定目前无明显规律可寻。另一方面,AdaptiveMethod通过将马尔可夫超链接矩阵稀疏化以达到节省迭代时间的目的。文章在PowerExtrapolation算法的基础上引入AdaptiveMethod,实验结果初步证明了新算法可以减少迭代运算的时间。 展开更多
关键词 链接分析 WEB信息检索 PAGERANK算法 POWER EXTRAPOLATION adaptive method
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3-D direct current resistivity forward modeling by adaptive multigrid finite element method 被引量:9
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作者 汤井田 王飞燕 +1 位作者 任政勇 郭荣文 《Journal of Central South University》 SCIE EI CAS 2010年第3期587-592,共6页
Based on the fact that 3-D model discretization by artificial could not always be successfully implemented especially for large-scaled problems when high accuracy and efficiency were required, a new adaptive multigrid... Based on the fact that 3-D model discretization by artificial could not always be successfully implemented especially for large-scaled problems when high accuracy and efficiency were required, a new adaptive multigrid finite element method was proposed. In this algorithm, a-posteriori error estimator was employed to generate adaptively refined mesh on a given initial mesh. On these iterative meshes, V-cycle based multigrid method was adopted to fast solve each linear equation with each initial iterative term interpolated from last mesh. With this error estimator, the unknowns were nearly optimally distributed on the final mesh which guaranteed the accuracy. The numerical results show that the multigrid solver is faster and more stable compared with ICCG solver. Meanwhile, the numerical results obtained from the final model discretization approximate the analytical solutions with maximal relative errors less than 1%, which remarkably validates this algorithm. 展开更多
关键词 adaptive multigrid a-posteriori error estimator unstructured mesh V-CYCLE finite element method
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Combined indirect and direct method for adaptive fuzzy output feedback control of nonlinear system 被引量:2
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作者 Ding Quanxin Chen Haitong +1 位作者 Jiang Changsheng Chen Zongji 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2007年第1期120-124,共5页
A novel control method for a general class of nonlinear systems using fuzzy logic systems (FLSs) is presertted. Indirect and direct methods are combined to design the adaptive fuzzy output feedback controller and a ... A novel control method for a general class of nonlinear systems using fuzzy logic systems (FLSs) is presertted. Indirect and direct methods are combined to design the adaptive fuzzy output feedback controller and a high-gain observer is used to estimate the derivatives of the system output. The closed-loop system is proven to be semiglobally uniformly ultimately bounded. In addition, it is shown that if the approximation accuracy of the fuzzy logic system is high enough and the observer gain is chosen sufficiently large, an arbitrarily small tracking error can be achieved. Simulation results verify the effectiveness of the newly designed scheme and the theoretical discussion. 展开更多
关键词 Nonlinear control systems Non-affine Combined indirect and direct method adaptive fuzzy controller High-gain observer (HGO)
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Optimization of buckling load for laminated composite plates using adaptive Kriging-improved PSO:A novel hybrid intelligent method 被引量:3
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作者 Behrooz Keshtegar Trung Nguyen-Thoi +1 位作者 Tam T.Truong Shun-Peng Zhu 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2021年第1期85-99,共15页
An effective hybrid optimization method is proposed by integrating an adaptive Kriging(A-Kriging)into an improved partial swarm optimization algorithm(IPSO)to give a so-called A-Kriging-IPSO for maximizing the bucklin... An effective hybrid optimization method is proposed by integrating an adaptive Kriging(A-Kriging)into an improved partial swarm optimization algorithm(IPSO)to give a so-called A-Kriging-IPSO for maximizing the buckling load of laminated composite plates(LCPs)under uniaxial and biaxial compressions.In this method,a novel iterative adaptive Kriging model,which is structured using two training sample sets as active and adaptive points,is utilized to directly predict the buckling load of the LCPs and to improve the efficiency of the optimization process.The active points are selected from the initial data set while the adaptive points are generated using the radial random-based convex samples.The cell-based smoothed discrete shear gap method(CS-DSG3)is employed to analyze the buckling behavior of the LCPs to provide the response of adaptive and input data sets.The buckling load of the LCPs is maximized by utilizing the IPSO algorithm.To demonstrate the efficiency and accuracy of the proposed methodology,the LCPs with different layers(2,3,4,and 10 layers),boundary conditions,aspect ratios and load patterns(biaxial and uniaxial loads)are investigated.The results obtained by proposed method are in good agreement with the literature results,but with less computational burden.By applying adaptive radial Kriging model,the accurate optimal resultsebased predictions of the buckling load are obtained for the studied LCPs. 展开更多
关键词 adaptive kriging Laminated composite plates Buckling optimization Smooth finite element methods Cell-based smoothed discrete shear gap method(CS-DSG3) Improved PSO
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Enhancing reliability assessment of curved low-stiffness track-viaducts with an adaptive surrogate-based approach emphasizing track dynamic geometric state
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作者 CHENG Fang LIU Hui YANG Rui 《Journal of Central South University》 CSCD 2024年第11期4262-4275,共14页
Traditional track dynamic geometric state(TDGS)simulation incurs substantial computational burdens,posing challenges for developing reliability assessment approach that accounts for TDGS.To overcome these,firstly,a si... Traditional track dynamic geometric state(TDGS)simulation incurs substantial computational burdens,posing challenges for developing reliability assessment approach that accounts for TDGS.To overcome these,firstly,a simulation-based TDGS model is established,and a surrogate-based model,grid search algorithm-particle swarm optimization-genetic algorithm-multi-output least squares support vector regression,is established.Among them,hyperparameter optimization algorithm’s effectiveness is confirmed through test functions.Subsequently,an adaptive surrogate-based probability density evolution method(PDEM)considering random track geometry irregularity(TGI)is developed.Finally,taking curved train-steel spring floating slab track-U beam as case study,the surrogate-based model trained on simulation datasets not only shows accuracy in both time and frequency domains,but also surpasses existing models.Additionally,the adaptive surrogate-based PDEM shows high accuracy and efficiency,outperforming Monte Carlo simulation and simulation-based PDEM.The reliability assessment shows that the TDGS part peak management indexes,left/right vertical dynamic irregularity,right alignment dynamic irregularity,and track twist,have reliability values of 0.9648,0.9918,0.9978,and 0.9901,respectively.The TDGS mean management index,i.e.,track quality index,has reliability value of 0.9950.These findings show that the proposed framework can accurately and efficiently assess the reliability of curved low-stiffness track-viaducts,providing a theoretical basis for the TGI maintenance. 展开更多
关键词 reliability assessment track dynamic geometric state hybrid machine learning algorithm adaptive learning strategy probability density evolution method
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h-ADAPTIVITY ANALYSIS BASED ON MULTIPLE SCALE REPRODUCING KERNEL PARTICLE METHOD 被引量:2
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作者 张智谦 周进雄 +2 位作者 王学明 张艳芬 张陵 《应用数学和力学》 EI CSCD 北大核心 2005年第8期972-978,共7页
An h-adaptivity analysis scheme based on multiple scale reproducing kernel particle method was proposed, and two node refinement strategies were constructed using searching-neighbor-nodes(SNN) and local-Delaunay-trian... An h-adaptivity analysis scheme based on multiple scale reproducing kernel particle method was proposed, and two node refinement strategies were constructed using searching-neighbor-nodes(SNN) and local-Delaunay-triangulation(LDT) tech-niques, which were suitable and effective for h-adaptivity analysis on 2-D problems with the regular or irregular distribution of the nodes. The results of multiresolution and h-adaptivity analyses on 2-D linear elastostatics and bending plate problems demonstrate that the improper high-gradient indicator will reduce the convergence property of the h-adaptivity analysis, and that the efficiency of the LDT node refinement strategy is better than SNN, and that the presented h-adaptivity analysis scheme is provided with the validity, stability and good convergence property. 展开更多
关键词 无网格方法 再生核质点法 多分辨分析 自适应分析
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Nonlinear adaptive optimal control for vehicle handling improvement through steer-by-wire system 被引量:8
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作者 Vahid Tavoosi Reza Kazemi Atta Oveisi 《Journal of Central South University》 SCIE EI CAS 2014年第1期100-112,共13页
A control algorithm for improving vehicle handling was proposed by applying right angle to the steering wheel,based on the nonlinear adaptive optimal control(NAOC).A nonlinear 4-DOF model was initially developed,then ... A control algorithm for improving vehicle handling was proposed by applying right angle to the steering wheel,based on the nonlinear adaptive optimal control(NAOC).A nonlinear 4-DOF model was initially developed,then it was simplified to a 2-DOF model with reasonable assumptions to design observer and optimal controllers.Then a simplified model was developed for steering system.The numerical simulations were carried out using vehicle parameters for standard maneuvers in dry and wet road conditions.Moreover,the hardware in the loop method was implemented to prove the controller ability in realistic conditions.Simulation results obviously show the effectiveness of NAOC on vehicle handling and reveal that the proposed controller can significantly improve vehicle handling during severe maneuvers. 展开更多
关键词 HANDLING vehicle STEER-BY-WIRE CONTROLLER nonlinear adaptive optimal control hardware loop method
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Adaptive threading strategy based on rolling characteristics analysis in hot strip rolling 被引量:2
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作者 PENG Wen CHEN Shu-zong +2 位作者 GONG Dian-yao LIU Zi-ying ZHANG Dian-hua 《Journal of Central South University》 SCIE EI CAS CSCD 2017年第7期1560-1572,共13页
In order to improve the threading stability and the head thickness precision in tandem hot rolling process, an adaptive threading strategy was proposed. The proposed strategy was realized by the rolling characteristic... In order to improve the threading stability and the head thickness precision in tandem hot rolling process, an adaptive threading strategy was proposed. The proposed strategy was realized by the rolling characteristics analysis, and factors which affect the rolling force and the final thickness were determined and analyzed based on the influence coefficients calculation process. An objective function consisting of the influenced factors was founded, and the disturbance quantity was obtained by minimizing the function with the Nelder-Mead simplex method, and the proposed adaptive threading strategy was realized based on the calculation results. The adaptive threading strategy has been applied to one 7-stand hot tandem mill successfully, actual statistics data show that the predicted rolling force prediction in the range of +/- 5.0% is improved to 97.8%, the head thickness precision in the range of +/- 35 mu m is improved to 98.5%, and the threading stability and the head thickness precision are enhanced to a high level. 展开更多
关键词 hot strip ROLLING adaptive THREADING ROLLING characteristics ANALYSIS influence COEFFICIENTS method SIMPLEX algorithm
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Adaptive Robust Control for A Class of Nonlinear Systems with Unknown Uncertainties 被引量:1
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作者 Li, L. Yang, G. Zhao, C. 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2001年第3期51-56,共6页
The problem of robust stabilization for nonlinear systems with partially known uncertainties is considered in this paper. The required information about uncertainties in the system is merely that the uncertainties are... The problem of robust stabilization for nonlinear systems with partially known uncertainties is considered in this paper. The required information about uncertainties in the system is merely that the uncertainties are bounded, but the upper bounds are incompletely known. This paper can be viewed as an extension of the work in reference [1]. To compensate the uncertainties, an adaptive robust controller based on Lyapunov method is proposed and the design algorithm is also suggested. Compared with some previous controllers which can only ensure ultimate uniform boundedness of the systems, the controller given in the paper can make sure that the obtained closed-loop system is asymptotically stable in the large. Simulations show that the method presented is available and effective. 展开更多
关键词 adaptive algorithms adaptive control systems Asymptotic stability Closed loop control systems Computer simulation Interfaces (computer) Lyapunov methods Robustness (control systems) Uncertain systems
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Nonlinear combined forecasting model based on fuzzy adaptive variable weight and its application 被引量:1
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作者 蒋爱华 梅炽 +1 位作者 鄂加强 时章明 《Journal of Central South University》 SCIE EI CAS 2010年第4期863-867,共5页
In order to enhance forecasting precision of problems about nonlinear time series in a complex industry system,a new nonlinear fuzzy adaptive variable weight combined forecasting model was established by using concept... In order to enhance forecasting precision of problems about nonlinear time series in a complex industry system,a new nonlinear fuzzy adaptive variable weight combined forecasting model was established by using conceptions of the relative error,the change tendency of the forecasted object,gray basic weight and adaptive control coefficient on the basis of the method of fuzzy variable weight.Based on Visual Basic 6.0 platform,a fuzzy adaptive variable weight combined forecasting and management system was developed.The application results reveal that the forecasting precisions from the new nonlinear combined forecasting model are higher than those of other single combined forecasting models and the combined forecasting and management system is very powerful tool for the required decision in complex industry system. 展开更多
关键词 nonlinear combined forecasting nonlinear time series method of fuzzy adaptive variable weight relative error adaptive control coefficient
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Adaptive Elastic Net方法在Cox模型变量选择中的研究 被引量:1
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作者 韦新星 李春红 戴洪帅 《西南大学学报(自然科学版)》 CAS CSCD 北大核心 2017年第9期88-94,共7页
将Adaptive Elastic Net方法运用于Cox模型的变量选择中,证明了在一定条件下,Cox模型的Adaptive Elastic Net估计具有组效应性质.数值模拟和具体实例验证了该估计的组效应性质,表明Cox模型的Adaptive Elastic Net方法优于Lasso方法、Ada... 将Adaptive Elastic Net方法运用于Cox模型的变量选择中,证明了在一定条件下,Cox模型的Adaptive Elastic Net估计具有组效应性质.数值模拟和具体实例验证了该估计的组效应性质,表明Cox模型的Adaptive Elastic Net方法优于Lasso方法、Adaptive Lasso方法和Elastic Net方法. 展开更多
关键词 adaptive ELASTIC Net方法 COX模型 变量选择 组效应性质
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An efficient adaptive space partitioning algorithm for electromagnetic scattering calculation of complex 3D models 被引量:1
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作者 HUANG Minjie ZHOU Yaoming +1 位作者 WANG Yongchao LIU Zhongtie 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2021年第5期1071-1082,共12页
The space partitioning algorithm based on the rounding and addressing operations has been proved to be an efficient space partitioning algorithm with the potential for real-time calculation.An improvement on this kind... The space partitioning algorithm based on the rounding and addressing operations has been proved to be an efficient space partitioning algorithm with the potential for real-time calculation.An improvement on this kind of space partitioning algorithms for solving complex 3D models is presented.Numerical examples show that the efficiency of the improved algorithm is better than that of the original method.When the size of most target elements is smaller than the size of spatial grids,the efficiency of the improved method can be more than four times of that of the original method.An adaptive method of space partitioning based on the improved algorithm is developed by taking the surface element density or the curvature as the threshold for deep partitioning and conducting the deep partitioning using the octree method.A computer program implementation for applying the method in some typical applications is discussed,and the performance in terms of the efficiency,reliability,and resource use is evaluated.Application testing shows that the results of the adaptive spacing partitioning are more convenient for the follow-up use than that of the basic uniform space partitioning.Furthermore,when it is used to calculate the electromagnetic scattering of complex targets by the ray tracing(RT)method,the adaptive space partitioning algorithm can reduce the calculation time of the RT process by more than 40%compared with the uniform space segmentation algorithm. 展开更多
关键词 adaptive space partitioning computer graphics binary space partitioning ray tracing(RT)method stealth technology
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Adaptive Stabilization and Trajectory Tracking of Airship with Neutral Buoyancy 被引量:10
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作者 ZHANG Yan QU Wei-Dong +1 位作者 XI Yu-Geng CAI Zi-Li 《自动化学报》 EI CSCD 北大核心 2008年第11期1437-1440,共4页
这份报纸介绍一个适应非线性的控制答案给一架自治飞艇的水平运动。我们定义包括配置错误和速度错误的错误功能的一个新奇家庭。然后,我们建立错误系统。稳定错误系统的适应非线性的控制器被 Lyapunov 直接方法和 Matrosov 定理设计。... 这份报纸介绍一个适应非线性的控制答案给一架自治飞艇的水平运动。我们定义包括配置错误和速度错误的错误功能的一个新奇家庭。然后,我们建立错误系统。稳定错误系统的适应非线性的控制器被 Lyapunov 直接方法和 Matrosov 定理设计。数字研究被介绍说明建议控制器的有效性。 展开更多
关键词 自适应系统 稳定性 轨迹 飞船 浮力
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Multivariable Adaptive Decoupling Controller Using Hierarchical Multiple Models 被引量:7
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作者 王昕 李少远 岳恒 《自动化学报》 EI CSCD 北大核心 2005年第2期223-230,共8页
To solve the problem such as too many models, long computing time and so on, a hierarchical multiple models direct adaptive decoupling controller is designed. It consists of multiple levels. In the upper level, the be... To solve the problem such as too many models, long computing time and so on, a hierarchical multiple models direct adaptive decoupling controller is designed. It consists of multiple levels. In the upper level, the best model is chosen according to the switching index. Then multiple fixed models are constructed on line to cover the region which the above chosen fixed model lies in.In the last level, one free-running and one re-initialized adaptive model are added to guarantee the stability and improve the transient response. By selection of the weighting polynomial matrix, it not only eliminates the steady output error and places the poles of the closed loop system arbitrarily, but also decouples the system dynamically. At last, for this multiple models switching system, global convergence is obtained under common assumptions. Compared with the conventional multiple models adaptive controller, it reduces the number of the fixed models greatly. If the same number of the fixed models is used, the system transient response and decoupling result are improved. The simulation example illustrates the power of the derived controller. 展开更多
关键词 分层递阶 多模型 自适应控制器 解耦 电极设置
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可压缩流动问题笛卡尔网格模拟方法研究进展与展望 被引量:1
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作者 赵宁 刘剑明 +1 位作者 田琳琳 王镇明 《力学学报》 北大核心 2025年第2期285-314,共30页
计算网格是复杂流动问题精细化模拟的先决条件,会对数值结果的准确性和可靠性产生重要影响.然而,高质量计算网格生成需要费时费力的人机交互过程且严重依赖于工程师的个人经验,使得现阶段计算流体力学(CFD)自动化程度处于较低水平.笛卡... 计算网格是复杂流动问题精细化模拟的先决条件,会对数值结果的准确性和可靠性产生重要影响.然而,高质量计算网格生成需要费时费力的人机交互过程且严重依赖于工程师的个人经验,使得现阶段计算流体力学(CFD)自动化程度处于较低水平.笛卡尔网格具备生成简单、内存要求低、计算效率高及自动性强等特点,使其能够极大减少网格生成过程中的人工成本,因而成为CFD社区的研究热点之一.对此,以笛卡尔网格可压缩流模拟为主线,结合课题组多年的研究成果对其中涉及的关键技术和国内外发展现状展开综述.首先简要概述了笛卡尔网格自适应方法及其数据结构,随后系统阐述了切割单元、浸入边界、重叠笛卡尔网格和混合笛卡尔网格等方法的发展现状及存在的问题,最后从自适应加密策略、动态并行技术、高保真计算方法、先进物理模型及实际工程应用等多个维度深入探讨了笛卡尔网格方法涉及的关键技术与未来发展趋势.通过全面回顾和深入分析笛卡尔网格方法的研究现状和发展动态,试图为读者提供一个清晰及全面的认识,并为相关领域的研究提供有益的参考和启示. 展开更多
关键词 笛卡尔网格 可压缩流动 壁面处理方法 自适应技术 高保真模拟
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等几何拓扑优化非齐次边界条件施加技术研究
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作者 王书亭 谢晴天 +3 位作者 杨奥迪 李小兵 熊体凡 谢贤达 《中国机械工程》 北大核心 2025年第3期525-535,共11页
非均匀有理B样条(NURBS)基函数缺乏插值性,导致等几何拓扑优化方法无法直接在控制顶点处施加非齐次边界条件。为此,介绍了面向等几何分析的两类非齐次边界条件处理方法,通过强施加方法和弱施加方法分别对边界条件施加的精度进行提升。... 非均匀有理B样条(NURBS)基函数缺乏插值性,导致等几何拓扑优化方法无法直接在控制顶点处施加非齐次边界条件。为此,介绍了面向等几何分析的两类非齐次边界条件处理方法,通过强施加方法和弱施加方法分别对边界条件施加的精度进行提升。数值算例结果验证了前述方法在等几何分析非齐次边界条件施加过程的可行性。将前述方法嵌入至等几何拓扑优化流程,创新性地提出惩罚因子自适应的非齐次边界条件处理方法,提高了等几何拓扑优化求解的精度,进一步论证了文中方法的有效性。 展开更多
关键词 等几何拓扑优化 非齐次边界条件 边界配点法 自适应罚函数法
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多谱自适应小波和盲源分离耦合的生理信号降噪方法
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作者 王振宇 向泽锐 +2 位作者 支锦亦 丁铁成 邹瑞 《北京航空航天大学学报》 北大核心 2025年第3期910-921,共12页
为提高生理信号的质量和可靠性,将盲源分离和小波阈值方法进行耦合研究,提出了多谱自适应小波信号增强方法并与改进的盲源分离方法相结合进行降噪处理。为评估所提方法的有效性,使用小波变换中软阈值、硬阈值、自适应阈值3种方法计算信... 为提高生理信号的质量和可靠性,将盲源分离和小波阈值方法进行耦合研究,提出了多谱自适应小波信号增强方法并与改进的盲源分离方法相结合进行降噪处理。为评估所提方法的有效性,使用小波变换中软阈值、硬阈值、自适应阈值3种方法计算信噪比(SNR)和均方根误差(RMSE)。结果表明:所提方法在软阈值下具有较强的适用性,增强后的信号软阈值相比硬阈值,SNR提升约44.2%,RMSE下降约28.8%,处理时间减少约1.4%。软阈值相比自适应阈值,SNR提升约706%,RMSE下降约16.7%,处理时间减少约3.0%。为对比软阈值下各参数差异,使用软阈值对原始信号、加噪信号和增强信号进行对比分析及归一化处理。结果显示增强后的信号具有较好的SNR、较低的RMSE和较短的处理时间,软阈值下增强后的信号与原始信号相比,SNR提升约0.12%,RMSE下降约2.5%,处理时间减少约3.9%,进一步验证了所提方法的有效性,并提高了信号质量。 展开更多
关键词 多谱自适应小波 盲源分离 小波变换 降噪方法 生理信号
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自适应步长增维精细积分法的电磁暂态仿真
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作者 叶婧 谢继豪 +2 位作者 王永 吕金伟 张磊 《电力系统及其自动化学报》 北大核心 2025年第3期149-158,共10页
针对电磁暂态仿真类程序中易有数值振荡的产生及采用定步长仿真难以兼顾精度和效率的问题,提出一种自适应步长增维精细积分仿真算法。首先,为避免矩阵求逆引入扩展向量进行增维,并对增维矩阵进行分块计算以降低计算规模;其次,根据估计... 针对电磁暂态仿真类程序中易有数值振荡的产生及采用定步长仿真难以兼顾精度和效率的问题,提出一种自适应步长增维精细积分仿真算法。首先,为避免矩阵求逆引入扩展向量进行增维,并对增维矩阵进行分块计算以降低计算规模;其次,根据估计误差确立自适应步长变化的依据,并通过预设步长进一步提高计算效率;最后,建立电磁暂态数值计算流程,对电力系统中线性与非线性元件进行建模,并通过典型的算例验证了所提算法的有效性与优势。 展开更多
关键词 电磁暂态仿真 数值振荡 增维精细积分法 自适应步长
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时频电磁法三维自适应有限元正演及含油储层灵敏度分析研究
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作者 李宗杰 蔡盼盼 +3 位作者 李清坤 秦策 高文龙 王绪本 《石油地球物理勘探》 北大核心 2025年第3期806-816,共11页
时频电磁法在油气勘探领域应用非常广泛。三维正演模拟能够获得地下三维电性结构的电磁响应,是电磁数据定性解释和电磁勘探观测系统设计的重要工具,也是三维反演的基础。利用时频电磁三维自适应有限元正演模拟算法,求解电场需满足的二... 时频电磁法在油气勘探领域应用非常广泛。三维正演模拟能够获得地下三维电性结构的电磁响应,是电磁数据定性解释和电磁勘探观测系统设计的重要工具,也是三维反演的基础。利用时频电磁三维自适应有限元正演模拟算法,求解电场需满足的二阶偏微分方程,并基于电磁场连续性条件估计后验误差,据此指导网格自适应加密,实现电磁响应的高效、精确模拟。相比传统正演方法,该方法能够在保证计算精度的前提下,有效减少计算量。通过数值算例验证算法的计算精度和效率,然后对油气模型进行模拟,分析时频电磁响应对储层的灵敏度。该研究为利用时频电磁法进行油气勘探提供了重要的参考。 展开更多
关键词 时频电磁法 三维正演 自适应有限元 油气勘探 电磁响应
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