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A Radial Basis Function Method with Improved Accuracy for Fourth Order Boundary Value Problems
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作者 Scott A. Sarra Derek Musgrave +1 位作者 Marcus Stone Joseph I. Powell 《Journal of Applied Mathematics and Physics》 2024年第7期2559-2573,共15页
Accurately approximating higher order derivatives is an inherently difficult problem. It is shown that a random variable shape parameter strategy can improve the accuracy of approximating higher order derivatives with... Accurately approximating higher order derivatives is an inherently difficult problem. It is shown that a random variable shape parameter strategy can improve the accuracy of approximating higher order derivatives with Radial Basis Function methods. The method is used to solve fourth order boundary value problems. The use and location of ghost points are examined in order to enforce the extra boundary conditions that are necessary to make a fourth-order problem well posed. The use of ghost points versus solving an overdetermined linear system via least squares is studied. For a general fourth-order boundary value problem, the recommended approach is to either use one of two novel sets of ghost centers introduced here or else to use a least squares approach. When using either ghost centers or least squares, the random variable shape parameter strategy results in significantly better accuracy than when a constant shape parameter is used. 展开更多
关键词 Numerical Partial Differential Equations Boundary Value Problems Radial Basis function methods Ghost Points Variable Shape Parameter least squares
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An Adaptive Least-Squares Mixed Finite Element Method for Fourth Order Parabolic Problems
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作者 Ning Chen Haiming Gu 《Applied Mathematics》 2013年第4期675-679,共5页
A least-squares mixed finite element (LSMFE) method for the numerical solution of fourth order parabolic problems analyzed and developed in this paper. The Ciarlet-Raviart mixed finite element space is used to approxi... A least-squares mixed finite element (LSMFE) method for the numerical solution of fourth order parabolic problems analyzed and developed in this paper. The Ciarlet-Raviart mixed finite element space is used to approximate. The a posteriori error estimator which is needed in the adaptive refinement algorithm is proposed. The local evaluation of the least-squares functional serves as a posteriori error estimator. The posteriori errors are effectively estimated. The convergence of the adaptive least-squares mixed finite element method is proved. 展开更多
关键词 ADAPTIVE method least-squares Mixed Finite Element method FOURTH Order Parabolic Problems least-squares functional A POSTERIORI Error
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A STUDY ON THE WEIGHT FUNCTION OF THE MOVING LEAST SQUARE APPROXIMATION IN THE LOCAL BOUNDARY INTEGRAL EQUATION METHOD 被引量:4
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作者 Long Shuyao Hu De’an (Department of Engineering Mechanics,Hunan University,Changsha 410082,China) 《Acta Mechanica Solida Sinica》 SCIE EI 2003年第3期276-282,共7页
The meshless method is a new numerical technique presented in recent years.It uses the moving least square(MLS)approximation as a shape function.The smoothness of the MLS approximation is determined by that of the bas... The meshless method is a new numerical technique presented in recent years.It uses the moving least square(MLS)approximation as a shape function.The smoothness of the MLS approximation is determined by that of the basic function and of the weight function,and is mainly determined by that of the weight function.Therefore,the weight function greatly affects the accuracy of results obtained.Different kinds of weight functions,such as the spline function, the Gauss function and so on,are proposed recently by many researchers.In the present work,the features of various weight functions are illustrated through solving elasto-static problems using the local boundary integral equation method.The effect of various weight functions on the accuracy, convergence and stability of results obtained is also discussed.Examples show that the weight function proposed by Zhou Weiyuan and Gauss and the quartic spline weight function are better than the others if parameters c and α in Gauss and exponential weight functions are in the range of reasonable values,respectively,and the higher the smoothness of the weight function,the better the features of the solutions. 展开更多
关键词 weight function meshless methods local boundary integral equation method moving least square approximation
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Predictive functional control based on fuzzy T-S model for HVAC systems temperature control 被引量:6
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作者 Hongli LU Lei JIA +1 位作者 Shulan KONG Zhaosheng ZHANG 《控制理论与应用(英文版)》 EI 2007年第1期94-98,共5页
In heating, ventilating and air-conditioning (HVAC) systems, there exist severe nonlinearity, time-varying nature, disturbances and uncertainties. A new predictive functional control based on Takagi-Sugeno (T-S) f... In heating, ventilating and air-conditioning (HVAC) systems, there exist severe nonlinearity, time-varying nature, disturbances and uncertainties. A new predictive functional control based on Takagi-Sugeno (T-S) fuzzy model was proposed to control HVAC systems. The T-S fuzzy model of stabilized controlled process was obtained using the least squares method, then on the basis of global linear predictive model from T-S fuzzy model, the process was controlled by the predictive functional controller. Especially the feedback regulation part was developed to compensate uncertainties of fuzzy predictive model. Finally simulation test results in HVAC systems control applications showed that the proposed fuzzy model predictive functional control improves tracking effect and robustness. Compared with the conventional PID controller, this control strategy has the advantages of less overshoot and shorter setting time, etc. 展开更多
关键词 T-S fuzzy model Predictive functional control least squares method HVAC systems
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The improved element-free Galerkin method forthree-dimensional wave equation 被引量:16
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作者 Zan Zhang Dong-Ming Li +1 位作者 Yu-Min Cheng Kim Moew Liew 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2012年第3期808-818,共11页
The paper presents the improved element-free Galerkin (IEFG) method for three-dimensional wave propa- gation. The improved moving least-squares (IMLS) approx- imation is employed to construct the shape function, w... The paper presents the improved element-free Galerkin (IEFG) method for three-dimensional wave propa- gation. The improved moving least-squares (IMLS) approx- imation is employed to construct the shape function, which uses an orthogonal function system with a weight function as the basis function. Compared with the conventional moving least-squares (MLS) approximation, the algebraic equation system in the IMLS approximation is not ill-conditioned, and can be solved directly without deriving the inverse matrix. Because there are fewer coefficients in the IMLS than in the MLS approximation, fewer nodes are selected in the IEFG method than in the element-free Galerkin method. Thus, the IEFG method has a higher computing speed. In the IEFG method, the Galerkin weak form is employed to obtain a dis- cretized system equation, and the penalty method is applied to impose the essential boundary condition. The traditional difference method for two-point boundary value problems is selected for the time discretization. As the wave equations and the boundary-initial conditions depend on time, the scal- ing parameter, number of nodes and the time step length are considered for the convergence study. 展开更多
关键词 Weighted orthogonal function Improved mov-ing least squares (IMLS) approximation. Improved element-free Galerkin (IEFG) method Penalty method Temporaldiscretization Wave equation
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A data-derived soft-sensor method for monitoring effluent total phosphorus 被引量:5
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作者 Shuguang Zhu Honggui Han +1 位作者 Min Guo Junfei Qiao 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2017年第12期1791-1797,共7页
The effluent total phosphorus(ETP) is an important parameter to evaluate the performance of wastewater treatment process(WWTP). In this study, a novel method, using a data-derived soft-sensor method, is proposed to ob... The effluent total phosphorus(ETP) is an important parameter to evaluate the performance of wastewater treatment process(WWTP). In this study, a novel method, using a data-derived soft-sensor method, is proposed to obtain the reliable values of ETP online. First, a partial least square(PLS) method is introduced to select the related secondary variables of ETP based on the experimental data. Second, a radial basis function neural network(RBFNN) is developed to identify the relationship between the related secondary variables and ETP. This RBFNN easily optimizes the model parameters to improve the generalization ability of the soft-sensor. Finally, a monitoring system, based on the above PLS and RBFNN, named PLS-RBFNN-based soft-sensor system, is developed and tested in a real WWTP. Experimental results show that the proposed monitoring system can obtain the values of ETP online and own better predicting performance than some existing methods. 展开更多
关键词 Data-derived soft-sensor Effluent total phosphorus Wastewater treatment process Radial basis function neural network Partial least square method
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A Local Meshless Method for Two Classes of Parabolic Inverse Problems
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作者 Wei Liu Baiyu Wang 《Journal of Applied Mathematics and Physics》 2018年第5期968-978,共11页
A local meshless method is applied to find the numerical solutions of two classes of inverse problems in parabolic equations. The problem is reconstructing the source term using a solution specified at some internal p... A local meshless method is applied to find the numerical solutions of two classes of inverse problems in parabolic equations. The problem is reconstructing the source term using a solution specified at some internal points;one class is that the source term is time dependent, and the other class is that the source term is time and space dependent. Some numerical experiments are presented and discussed. 展开更多
关键词 MESHLESS method Moving least squares LOCAL Radial Basis functions Inverse Problem PARABOLIC Equation
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EFFICIENT DESIGN METHOD OF COSINE-MODULATED QMF BANKS SATISFYING PR PROPERTY
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作者 Tan Ying He Zhenya(Department of Radio Engineering, Southeast University, Nanjing 210096) 《Journal of Electronics(China)》 1999年第1期51-57,共7页
In this paper the design problem of perfect-reconstruction cosine-modulated QMF banks has been formulated as a quadratic-constrained least-squares (QCLS) minimization problem in which all constrained matrices of the Q... In this paper the design problem of perfect-reconstruction cosine-modulated QMF banks has been formulated as a quadratic-constrained least-squares (QCLS) minimization problem in which all constrained matrices of the QCLS optimization problem are symmetric and positive definite. A cost function which is a convex function of desired prototype filter coefficients is constructed so that this kind of QCLS optimization problems can be efficiently solved. So a global minimizer of this problem can be easily obtained. Results of two design examples are presented to support the derivations and analyses. 展开更多
关键词 Quadratic-constrained least-squares(QCLS) cosine-modulated QMF BANKS Global optimization Penalty function searching (PS) approach
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AN IMPROVED WOODWARD METHOD FOR SEPARATE ARRAYS SYNTHESIS
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作者 Bian Li WU Qun 《Journal of Electronics(China)》 2010年第2期256-260,共5页
Based on the property of sample function,the Woodward synthesis method for separate arrays is improved. The improved method is justified theoretically,and the sample function of the flat-topping and 30 degree cosecant... Based on the property of sample function,the Woodward synthesis method for separate arrays is improved. The improved method is justified theoretically,and the sample function of the flat-topping and 30 degree cosecant-squared space segment pattern on radar phased array antenna is synthesized using it. Through simulation and analysis,it can be used fewer elements to make the same synthesis effect on the pattern with the traditional Woodward method. And if the same number of elements is used,the synthesized pattern using the improved method will have better approach to the sample function,narrower beam width,and higher gain. 展开更多
关键词 Antenna synthesis Woodward method Sample function Cosecant-squared pattern
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The Extended Tanh Method for Compactons and Solitons Solutions for the CH(<i>n</i>,2<i>n</i>– 1,2<i>n</i>,–<i>n</i>) Equations
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作者 Xinqian Lin Shengqiang Tang Wentao Huang 《Journal of Information Security》 2012年第3期185-188,共4页
In this paper, by using the sine-cosine method, the extended tanh-method, and the rational hyperbolic functions method, we study a class of nonlinear equations which derived from a fourth order analogue of generalized... In this paper, by using the sine-cosine method, the extended tanh-method, and the rational hyperbolic functions method, we study a class of nonlinear equations which derived from a fourth order analogue of generalized Camassa-Holm equation. It is shown that this class gives compactons, solitary wave solutions, solitons, and periodic wave solutions. The change of the physical structure of the solutions is caused by variation of the exponents and the coefficients of the derivatives. 展开更多
关键词 The CH(n 2n 1 2n –n) Equation COMPACTONS Sine-cosine method and the Extended Tanh method Rational Hyperbolic functions method
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考虑国际金融风险影响的上证50ETF期权定价研究
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作者 孙有发 姚宇航 +2 位作者 龚翼山 邱梓杰 刘彩燕 《运筹与管理》 CSSCI CSCD 北大核心 2024年第6期207-213,共7页
近年来如何刻画国际金融风险对中国市场的影响,成为学术界的热门热点之一。已有文献大多集中于研究国际股票市场之间的风险溢出效应,较少关注国际股票市场对中国期权市场的风险外溢效应。本文将标普500ETF走势嵌入上证50ETF的收益率过程... 近年来如何刻画国际金融风险对中国市场的影响,成为学术界的热门热点之一。已有文献大多集中于研究国际股票市场之间的风险溢出效应,较少关注国际股票市场对中国期权市场的风险外溢效应。本文将标普500ETF走势嵌入上证50ETF的收益率过程,构建IFR_BS模型(BS Model with the Impact of International Financial Risk);然后应用特征函数微扰法和Fourier-Cosine定价方法,推导出该模型下欧式期权的近似解析定价公式。数值实验和实证结果表明:(1)IFR_BS模型可以较好地刻画上证50ETF收益率分布的“尖峰”、“肥尾”和“有偏”等统计特征。(2)考虑国际金融风险溢价的IFR_BS模型下的期权定价公式,可以解决BS模型对短到期期权尤其是短到期深度OTM期权估值不足的问题。 展开更多
关键词 期权定价 国际金融风险 欠阻尼函数 特征函数微扰法 Fourier-cosine方法
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磁电弹性材料中含有带四条裂纹的正方形孔的反平面断裂问题
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作者 徐燕 杨娟 《工程数学学报》 CSCD 北大核心 2024年第1期175-185,共11页
针对反平面剪切力作用下,磁电弹性材料中含有带四条裂纹的正方形孔口的断裂问题进行了深入地探索。基于线弹性断裂理论和Riemann-Schwarz解析延拓定理,利用复变函数方法和留数定理,通过构造合适的数值保角映射函数,将解析函数边值问题... 针对反平面剪切力作用下,磁电弹性材料中含有带四条裂纹的正方形孔口的断裂问题进行了深入地探索。基于线弹性断裂理论和Riemann-Schwarz解析延拓定理,利用复变函数方法和留数定理,通过构造合适的数值保角映射函数,将解析函数边值问题转化为柯西积分方程组进行解答,获得了磁电非渗透边界条件下裂纹尖端断裂力学参数的显式表达式。通过与已有结果的对比,验证了方法的有效性。利用数值算例描述了孔洞尺寸、四条裂纹长度和机–电–磁载荷等因素对裂纹扩展参数的影响规律。结果表明:水平右裂纹对孔口裂纹扩展影响更显著;垂直裂纹影响水平裂纹的扩展趋势;在磁电非渗透边界条件下,随着机械载荷的增大,裂纹尖端的应力强度因子变大,而电载荷和磁载荷对裂纹的扩展与机械载荷的大小和方向密切相关。该分析方法为求解复杂多连通域的智能复合材料问题提供了一条有效途径,研究成果为含裂纹的复合材料或结构的优化设计提供了科学依据。 展开更多
关键词 复变函数方法 磁电弹性材料 正方形孔边裂纹 场强度因子 能量释放率
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基于改进K-means的局部离群点检测方法
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作者 周玉 夏浩 +1 位作者 岳学震 王培崇 《工程科学与技术》 EI CAS CSCD 北大核心 2024年第4期66-77,共12页
离群点检测任务是指检测与正常数据在特征属性上存在显著差异的异常数据。大多数基于聚类的离群点检测方法主要从全局角度对数据集中的离群点进行检测,而对局部离群点的检测性能较弱。基于此,本文通过引入快速搜索和发现密度峰值方法改... 离群点检测任务是指检测与正常数据在特征属性上存在显著差异的异常数据。大多数基于聚类的离群点检测方法主要从全局角度对数据集中的离群点进行检测,而对局部离群点的检测性能较弱。基于此,本文通过引入快速搜索和发现密度峰值方法改进K-means聚类算法,提出了一种名为KLOD(local outlier detection based on improved K-means and least-squares methods)的局部离群点检测方法,以实现对局部离群点的精确检测。首先,利用快速搜索和发现密度峰值方法计算数据点的局部密度和相对距离,并将二者相乘得到γ值。其次,将γ值降序排序,利用肘部法则选择γ值最大的k个数据点作为K-means聚类算法的初始聚类中心。然后,通过K-means聚类算法将数据集聚类成k个簇,计算数据点在每个维度上的目标函数值并进行升序排列。接着,确定数据点的每个维度的离散程度并选择适当的拟合函数和拟合点,通过最小二乘法对升序排列的每个簇的每1维目标函数值进行函数拟合并求导,以获取变化率。最后,结合信息熵,将每个数据点的每个维度目标函数值乘以相应的变化率进行加权,得到最终的异常得分,并将异常值得分较高的top-n个数据点视为离群点。通过人工数据集和UCI数据集,对KLOD、LOF和KNN方法在准确度上进行仿真实验对比。结果表明KLOD方法相较于KNN和LOF方法具有更高的准确度。本文提出的KLOD方法能够有效改善K-means聚类算法的聚类效果,并且在局部离群点检测方面具有较好的精度和性能。 展开更多
关键词 离群点检测 K均值聚类 最小二乘法 密度峰值 目标函数值
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基于分数阶黏壶元件的岩石损伤蠕变模型
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作者 荣传新 王镇森 +1 位作者 安刚建 施鑫 《安徽理工大学学报(自然科学版)》 CAS 2024年第3期35-41,共7页
目的为了建立一个能描述岩石蠕变全过程的蠕变模型。方法首先以分数阶黏壶元件描述岩石的黏弹性,采用基于Kachanov损伤率公式的损伤体描述岩石的粘塑性并串联一个胡克体建立成只有四个元件的蠕变模型。然后,将其本构方程推广到三维应力... 目的为了建立一个能描述岩石蠕变全过程的蠕变模型。方法首先以分数阶黏壶元件描述岩石的黏弹性,采用基于Kachanov损伤率公式的损伤体描述岩石的粘塑性并串联一个胡克体建立成只有四个元件的蠕变模型。然后,将其本构方程推广到三维应力状态,考虑球应力,并引入一个屈服函数来准确判断岩石是否发生非稳定蠕变。最后,采用最小二乘法分析得到模型参数,用红砂岩和砂质泥岩的蠕变实验数据验证模型的有效性。结果新的蠕变模型理论曲线与实验数据曲线吻合较好,可以描述岩石蠕变的全过程。结论新的蠕变模型解决了经典模型在描述岩石蠕变时的模型复杂和参数较多的问题,对研究岩石蠕变特性具有一定的参考价值。 展开更多
关键词 分数阶黏壶元件 损伤 蠕变模型 屈服函数 最小二乘法
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基于快速进行平方算法的巡检机器人路径规划研究
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作者 武刚 许家元 邸迪 《机械与电子》 2024年第2期74-80,共7页
针对目前快速行进平方法在实际场景中对Sat值选取缺乏评价尺度的问题,提出一种改进的快速行进平方法以应用于巡检机器人的路径规划。该改进方法引入路径评价函数,通过对机器人行驶距离、行驶角度变化量和与障碍物的距离进行无量纲化处理... 针对目前快速行进平方法在实际场景中对Sat值选取缺乏评价尺度的问题,提出一种改进的快速行进平方法以应用于巡检机器人的路径规划。该改进方法引入路径评价函数,通过对机器人行驶距离、行驶角度变化量和与障碍物的距离进行无量纲化处理,以获取当前环境下最优的截止阈值参数Sat。构建了PID控制算法,校正了机器人的动作误差。使用MATLAB软件绘制实际运动轨迹,比较相关路径参数。仿真实验表明,改进后的快速行进平方法可根据截止阈值参数Sat生成适用于不同车型和环境特点的最优路径。该研究的改进方法为巡检机器人在实际应用中的路径规划提供了参考。 展开更多
关键词 路径规划 移动机器人 快速行进平方法 碰撞风险 评价函数
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基于改进权函数距离的机器人运动偏差补偿算法设计 被引量:1
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作者 李晓梅 黄建勇 张泽治 《吉林大学学报(信息科学版)》 CAS 2024年第1期86-92,共7页
针对机器人在组装和生产过程中,由于几何参数存在一定误差,使连杆以及关节处等不可避免地出现细微差别,对机器人运动精度产生一定影响问题,提出了基于改进权函数距离的机器人运动偏差补偿算法设计方案。在定位机器人位置前添加扭角,获... 针对机器人在组装和生产过程中,由于几何参数存在一定误差,使连杆以及关节处等不可避免地出现细微差别,对机器人运动精度产生一定影响问题,提出了基于改进权函数距离的机器人运动偏差补偿算法设计方案。在定位机器人位置前添加扭角,获取机器人两坐标系间转换矩阵,根据线性标定计算机器人运动定位的绝对误差,利用改进权函数建立机器人距离误差数学模型,初步补偿运动误差。计算机器人末端执行器中心点位置和姿态的偏差,将补偿问题转化成机器人运动优化问题,得出运动偏差优化问题目标函数,经多次迭代得出最终补偿结果。实验结果表明,所提方法的误差补偿效果佳,重心补偿后的机器人运行稳定性好。 展开更多
关键词 改进权函数 机器人 运动偏差 偏差补偿 运动偏差辨识 最小二乘法 极大似然估计法 绝对定位偏差
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广义二型模糊系统的自组织规则生成方法
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作者 范轶博 赵涛 解相朋 《智能系统学报》 CSCD 北大核心 2024年第3期646-652,共7页
针对广义二型模糊系统在复杂情况中因缺乏专家经验而难以构建合适模糊规则的问题,提出了一种基于输入数据的激活强度来生成广义二型模糊集以及模糊规则的方法。通过数据驱动自组织构建广义二型模糊系统模糊规则,并且使用迭代最小二乘法... 针对广义二型模糊系统在复杂情况中因缺乏专家经验而难以构建合适模糊规则的问题,提出了一种基于输入数据的激活强度来生成广义二型模糊集以及模糊规则的方法。通过数据驱动自组织构建广义二型模糊系统模糊规则,并且使用迭代最小二乘法和梯度下降法优化系统前后件参数。最后,分别在无扰动和施加噪声情况下进行了非线性系统的跟踪仿真,实验结果证明了自组织规则生成的广义二型模糊系统的有效性,并能够以较高精度跟踪参考轨迹。 展开更多
关键词 自组织学习 模糊控制 广义二型模糊系统 隶属函数 结构学习 误差驱动 增量学习 递归最小二乘法
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一类随机SIR传染病模型的非标准数值离散化
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作者 谭伟 刘茂省 《西北师范大学学报(自然科学版)》 2024年第1期30-38,共9页
研究一个具有饱和发生率和疫苗接种率的随机离散SIR传染病模型的稳定性.首先,引入一个具有饱和发生率和疫苗接种率的确定性SIR模型,考虑到随机噪声对疾病传播有很大影响,应用非标准有限差分(NSFD)方法将模型离散化,最终得到一个随机离散... 研究一个具有饱和发生率和疫苗接种率的随机离散SIR传染病模型的稳定性.首先,引入一个具有饱和发生率和疫苗接种率的确定性SIR模型,考虑到随机噪声对疾病传播有很大影响,应用非标准有限差分(NSFD)方法将模型离散化,最终得到一个随机离散的SIR传染病模型.这种离散方法是对系统的右侧进行局部离散,得出离散模型,然后系统左侧用广义前向差分法对一阶导数进行逼近,并且要选取恰当的分母函数.其次,应用Lyapunov函数和矩阵方法给出了系统平衡解稳定的充分条件,并且得到了非线性差分方程概率稳定的充分条件和线性差分方程渐近均方稳定的充分条件.最后,通过数值仿真对理论分析结论进行验证. 展开更多
关键词 饱和发生率 随机离散模型 非标准有限差分方法 LYAPUNOV函数 渐近均方稳定
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基于神经网络的智能电网稳定性预测模型研究
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作者 杨熠鑫 《微型电脑应用》 2024年第1期180-183,共4页
目前,在智能电网稳定性预测方面,机器学习发挥着越来越重要的作用。鉴于传统预测模型存在多种假设和预测不精确的缺点,提出了一种基于神经网络的智能电网稳定性预测模型,该模型以前馈神经网络为基础,采用考虑反应时间的阻尼最小二乘法... 目前,在智能电网稳定性预测方面,机器学习发挥着越来越重要的作用。鉴于传统预测模型存在多种假设和预测不精确的缺点,提出了一种基于神经网络的智能电网稳定性预测模型,该模型以前馈神经网络为基础,采用考虑反应时间的阻尼最小二乘法对数据进行训练,将消耗、生产的有功功率和弹性系数作为输入变量,对表征智能电网稳定性的特征根实部进行预测,模型在隐藏层的激活函数采用双极性S函数(tansig),输出层的激活函数采用线性传递函数(purelin)。模型采用均方误差(MSE)和决定系数(R-Square,R2)对预测模型精确性和有效性进行评估。预测结果表明,该预测模型在训练和测试阶段均具有足够准确的预测性能,在预测范围具有极低MSE值和极大R2值,对不同潮流下智能电网稳定性的预测表现出了极高的准确性。 展开更多
关键词 神经网络 智能电网 阻尼最小二乘法 激活函数 稳定性预测
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一种应用于5G功率放大器的自适应探测技术研究
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作者 陈丽琴 《通信与信息技术》 2024年第2期46-49,63,共5页
众多研究发现5G体系结构中功率放大器(PA:Power Amplifier)存在着非线性特征,这使得信号传输过程中会出现失真。目前采用的DPD(Digital Adaptive Predistortion:数字自适应预失真)方法降低失真效果并不理想。在大数据输入时,会导致功率... 众多研究发现5G体系结构中功率放大器(PA:Power Amplifier)存在着非线性特征,这使得信号传输过程中会出现失真。目前采用的DPD(Digital Adaptive Predistortion:数字自适应预失真)方法降低失真效果并不理想。在大数据输入时,会导致功率放大器拥塞饱和、DPD输出功率非线性、收敛性降低以及信号信息相互干扰等情况出现。通过分析数字预失真系统,构建特征函数和探测函数模型,提出一种全新的基于LUT的自适应探测技术并对其进行性能仿真评估。通过测量收敛速度和动态信号功率的变化,可以得出特征函数和功率放大器自适应探测技术相结合具有较好的性能、较快的收敛速度和较少的计算步骤,能够有效地增强DPD方法降低失真的性能。 展开更多
关键词 无线通信 失真 特征函数 最小二乘法 收敛 基函数 取样频率
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