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The Hidden Geometry of the Babylonian Square Root Method
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作者 Fernanda Jaiara Dellajustina Luciano Camargo Martins 《Applied Mathematics》 2014年第19期2982-2987,共6页
We propose and demonstrate an original geometric argument for the ancient Babylonian square root method, which is analyzed and compared to the Newton-Raphson method. Based on simple geometry and algebraic analysis the... We propose and demonstrate an original geometric argument for the ancient Babylonian square root method, which is analyzed and compared to the Newton-Raphson method. Based on simple geometry and algebraic analysis the former original iterated map is derived and reinterpreted. Time series, fixed points, stability analysis and convergence schemes are studied and compared for both methods, in the approach of discrete dynamical systems. 展开更多
关键词 Babylonian square root method NEWTON-RAPHSON method ITERATED Map DYNAMICAL Systems
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A New Method of Embedded Fourth Order with Four Stages to Study Raster CNN Simulation 被引量:2
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作者 R. Ponalagusamy S. Senthilkumar 《International Journal of Automation and computing》 EI 2009年第3期285-294,共10页
A new Runge-Kutta (PK) fourth order with four stages embedded method with error control is presentea m this paper for raster simulation in cellular neural network (CNN) environment. Through versatile algorithm, si... A new Runge-Kutta (PK) fourth order with four stages embedded method with error control is presentea m this paper for raster simulation in cellular neural network (CNN) environment. Through versatile algorithm, single layer/raster CNN array is implemented by incorporating the proposed technique. Simulation results have been obtained, and comparison has also been carried out to show the efficiency of the proposed numerical integration algorithm. The analytic expressions for local truncation error and global truncation error are derived. It is seen that the RK-embedded root mean square outperforms the RK-embedded Heronian mean and RK-embedded harmonic mean. 展开更多
关键词 Raster scheme cellular neural network (CNN) numerical integration techniques edge detection new embedded RungeKutta root mean square (RKARMS (4 4)) method truncation errors.
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On the Application of Bootstrap Method to Stationary Time Series Process
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作者 T. O. Olatayo 《American Journal of Computational Mathematics》 2013年第1期61-65,共5页
This article introduces a resampling procedure called the truncated geometric bootstrap method for stationary time series process. This procedure is based on resampling blocks of random length, where the length of eac... This article introduces a resampling procedure called the truncated geometric bootstrap method for stationary time series process. This procedure is based on resampling blocks of random length, where the length of each blocks has a truncated geometric distribution and capable of determining the probability p and number of block b. Special attention is given to problems with dependent data, and application with real data was carried out. Autoregressive model was fitted and the choice of order determined by Akaike Information Criterion (AIC) and Bayesian Information Criterion (BIC). The normality test was carried out on the residual variance of the fitted model using Jargue-Bera statistics, and the best model was determined based on root mean square error of the forecasting values. The bootstrap method gives a better and a reliable model for predictive purposes. All the models for the different block sizes are good. They preserve and maintain stationary data structure of the process and are reliable for predictive purposes, confirming the efficiency of the proposed method. 展开更多
关键词 TRUNCATED Geometric Bootstrap method AUTOREGRESSIVE Model Akaike INFORMATION CRITERION (AIC) Bayesian INFORMATION CRITERION (BIC) root Mean square Error ()
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Film-Forming Properties of Fullerene Derivatives in Electrospray Deposition Method
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作者 Kazumasa Takeshi Kenji Takagi +2 位作者 Takeshi Fukuda Teiji Chihara Yusuke Tajima 《Journal of Surface Engineered Materials and Advanced Technology》 2013年第1期84-88,共5页
Thin films of three types of fullerene derivatives were prepared through the electrospray deposition (ESD) method. The optimized conditions for the fabrication of the thin films were investigated for different types o... Thin films of three types of fullerene derivatives were prepared through the electrospray deposition (ESD) method. The optimized conditions for the fabrication of the thin films were investigated for different types of fullerene derivatives: [6,6]-phenyl-C61-butyric acid methyl ester, [6,6]-phenyl-C71-butyric acid methyl ester, and indene-C60-monoadduct. The spray diameter during the ESD process was observed as a function of the supply rate achieved by changing the applied voltage. In all cases, the spray diameter increased with increasing applied voltage, reaching the maximum diameter (Dmax) in the voltage range 4 to 6 kV. It was clear that Dmax was influenced by the dipole moments of the fullerene derivatives (as calculated by density functional theory methods). Scanning electron microscopy observation of the?fabricated thin films showed that imbricated structures were formed through the stacking of the fullerene-derivative sheets. Atomic force microscopy images revealed that the density of the imbricated structure was dependent on the spray diameter during the ESD process, and the root-mean-square roughness of the film surface decreased with increasing applied voltage. These findings suggest that the ESD method will be effective for the preparation of fullerene-derivative thin films for the production of organic devices. 展开更多
关键词 ELECTROSPRAY Deposition method FULLERENE Derivative Thin FILM Scanning Electron MICROSCOPE Imbricated Structure Atomic Force MICROSCOPE root-Mean-square ROUGHNESS
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基于车桥耦合振动的双层钢桁梁斜拉桥行车舒适度分析
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作者 陈建兵 徐同源 +1 位作者 刘晨光 匡冠桦 《沈阳建筑大学学报(自然科学版)》 北大核心 2025年第1期95-104,共10页
探究车辆在双层钢桁梁斜拉桥的行车舒适性,为优化双层桥梁结构设计理论提供依据。以车桥耦合振动理论为基础,利用ANSYS分析软件进行数值模拟,通过求解车体的振动加速度,并根据《机械振动和冲击—评估人体暴露于全身振动的情况》(ISO2631... 探究车辆在双层钢桁梁斜拉桥的行车舒适性,为优化双层桥梁结构设计理论提供依据。以车桥耦合振动理论为基础,利用ANSYS分析软件进行数值模拟,通过求解车体的振动加速度,并根据《机械振动和冲击—评估人体暴露于全身振动的情况》(ISO2631-1)中均方根乘值法对乘车舒适性进行评价,探究了单(双)层加载、车速、车载质量、桥面不平顺度、车辆间距、车辆数目等因素对行车舒适性的影响。相较于单层通车,上下层同时通车时车体的振动强度略微降低;当车载质量越小或车速越大时,车体的加速度均方根值会逐渐增大;路面对车体振动强度影响较大,当路面等级处于较差的D级和E级时,车体振动强度会成倍增加。双层同时加载时,车辆的行车舒适性略优于单层通车;保持适当的车速或增大车载质量可以提高司乘人员的行车舒适性;行车舒适性对于路面等级较为敏感,当路面等级较差时,车内司乘人员受其影响无法长时间乘车。 展开更多
关键词 双层钢桁梁斜拉桥 车桥耦合 加速度均方根乘值法 行车舒适性
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Inverse-square-root-acceleration method for predicting the failure time of landslides 被引量:1
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作者 ZHOU XiaoPing YE Teng 《Science China(Technological Sciences)》 SCIE EI CAS CSCD 2021年第5期1127-1136,共10页
Predicting the failure time of unstable slopes is one of the most pivotal issues. In this paper, the inverse square root acceleration(INSRA) method was proposed to estimate the time-of-failure(TOF) of landslides. Four... Predicting the failure time of unstable slopes is one of the most pivotal issues. In this paper, the inverse square root acceleration(INSRA) method was proposed to estimate the time-of-failure(TOF) of landslides. Four collapsed slopes were presented in the three open-pit mines, two of them were probed by ground-based radar, and two of them were obtained from previous scientific papers. The inverse velocity(INV) method and INSRA method were adopted to analyze these four landslides and one slope which had great deformation but did not reach failure. Compared with the traditional INV method, the INSRA method can promote the forecasting effectiveness and has the advantage of higher accuracy. 展开更多
关键词 failure time of landslide inverse square root of acceleration traditional inverse velocity method
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基于平方和方法的电力系统稳定域估计
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作者 张巍巍 李兆明 +2 位作者 师洪涛 高峰 张白 《现代电子技术》 北大核心 2025年第4期97-101,共5页
目前对电力系统稳定性分析主要使用小信号分析方法,但当大信号扰动发生时,电力系统内在的非线性无法忽略,小信号分析方法的有效性值得商榷。在大信号扰动时,构造合理的暂态能量函数并确定系统临界稳定对应的函数值(临界能量),从而确定... 目前对电力系统稳定性分析主要使用小信号分析方法,但当大信号扰动发生时,电力系统内在的非线性无法忽略,小信号分析方法的有效性值得商榷。在大信号扰动时,构造合理的暂态能量函数并确定系统临界稳定对应的函数值(临界能量),从而确定稳定域并非易事。为此,提出一种基于多项式表达的平方和方法来估计电力系统的稳定域。该方法将电力系统通过多项式近似的方式表达,利用平方和方法将李雅谱诺夫函数的构造问题转化为线性矩阵不等式的可行解问题,通过数值计算得到构造的李雅谱诺夫函数,再通过优化计算得到稳定域的边界。最后采用数值算例验证了所提估计方法的可行性和有效性。 展开更多
关键词 电力系统 稳定域 平方和方法 多项式近似 李雅谱诺夫函数 线性矩阵不等式 算例验证
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Prediction of Time Series Empowered with a Novel SREKRLS Algorithm 被引量:3
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作者 Bilal Shoaib Yasir Javed +6 位作者 Muhammad Adnan Khan Fahad Ahmad Rizwan Majeed Muhammad Saqib Nawaz Muhammad Adeel Ashraf Abid Iqbal Muhammad Idrees 《Computers, Materials & Continua》 SCIE EI 2021年第5期1413-1427,共15页
For the unforced dynamical non-linear state–space model,a new Q1 and efficient square root extended kernel recursive least square estimation algorithm is developed in this article.The proposed algorithm lends itself ... For the unforced dynamical non-linear state–space model,a new Q1 and efficient square root extended kernel recursive least square estimation algorithm is developed in this article.The proposed algorithm lends itself towards the parallel implementation as in the FPGA systems.With the help of an ortho-normal triangularization method,which relies on numerically stable givens rotation,matrix inversion causes a computational burden,is reduced.Matrix computation possesses many excellent numerical properties such as singularity,symmetry,skew symmetry,and triangularity is achieved by using this algorithm.The proposed method is validated for the prediction of stationary and non-stationary Mackey–Glass Time Series,along with that a component in the x-direction of the Lorenz Times Series is also predicted to illustrate its usefulness.By the learning curves regarding mean square error(MSE)are witnessed for demonstration with prediction performance of the proposed algorithm from where it’s concluded that the proposed algorithm performs better than EKRLS.This new SREKRLS based design positively offers an innovative era towards non-linear systolic arrays,which is efficient in developing very-large-scale integration(VLSI)applications with non-linear input data.Multiple experiments are carried out to validate the reliability,effectiveness,and applicability of the proposed algorithm and with different noise levels compared to the Extended kernel recursive least-squares(EKRLS)algorithm. 展开更多
关键词 Kernel methods square root adaptive filtering givens rotation mackey glass time series prediction recursive least squares kernel recursive least squares extended kernel recursive least squares square root extended kernel recursive least squares algorithm
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A computational model of the human glucose-insulin regulatory system 被引量:2
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作者 Keh-Dong Shiang Fouad Kandeel 《The Journal of Biomedical Research》 CAS 2010年第5期347-364,共18页
Objective:A computational model of insulin secretion and glucose metabolism for assisting the diagnosis of diabetes mellitus in clinical research is introduced.The proposed method for the estimation of parameters for... Objective:A computational model of insulin secretion and glucose metabolism for assisting the diagnosis of diabetes mellitus in clinical research is introduced.The proposed method for the estimation of parameters for a system of ordinary differential equations(ODEs)that represent the time course of plasma glucose and insulin concentrations during glucose tolerance test(GTT)in physiological studies is presented.The aim of this study was to explore how to interpret those laboratory glucose and insulin data as well as enhance the Ackerman mathematical model.Methods:Parameters estimation for a system of ODEs was performed by minimizing the sum of squared residuals(SSR)function,which quantifies the difference between theoretical model predictions and GTT's experimental observations.Our proposed perturbation search and multiple-shooting methods were applied during the estimating process.Results:Based on the Ackerman's published data,we estimated the key parameters by applying R-based iterative computer programs.As a result,the theoretically simulated curves perfectly matched the experimental data points.Our model showed that the estimated parameters,computed frequency and period values,were proven a good indicator of diabetes.Conclusion:The present paper introduces a computational algorithm to biomedical problems,particularly to endocrinology and metabolism fields,which involves two coupled differential equations with four parameters describing the glucose-insulin regulatory system that Ackerman proposed earlier.The enhanced approach may provide clinicians in endocrinology and metabolism field insight into the transition nature of human metabolic mechanism from normal to impaired glucose tolerance. 展开更多
关键词 Coupled ordinary differential equations glucose tolerance test parameters estimation sum of squared residuals cost function multiple shooting method
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A Study of Some Properties of Bottomonium 被引量:1
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作者 A. M. Yasser G. S. Hassan T. A. Nahool 《Journal of Modern Physics》 2014年第17期1938-1944,共7页
We apply matrix Numerov’s method to obtain the radial wave functions;from these wave functions we calculate the root mean square radius rms and β coefficients of bottomonium . The obtained results have implications ... We apply matrix Numerov’s method to obtain the radial wave functions;from these wave functions we calculate the root mean square radius rms and β coefficients of bottomonium . The obtained results have implications for decay constants, decay widths and differential cross sections of heavy mesons. 展开更多
关键词 Matrix Numerov’s method Wave FUNCTIONS β COEFFICIENT root Mean square RADIUS BOTTOMONIUM
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Adaptive Gaussian sum squared-root cubature Kalman filter with split-merge scheme for state estimation 被引量:5
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作者 Liu Yu Dong Kai +3 位作者 Wang Haipeng Liu Jun He You Pan Lina 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2014年第5期1242-1250,共9页
The paper deals with state estimation problem of nonlinear non-Gaussian discrete dynamic systems for improvement of accuracy and consistency. An efficient new algorithm called the adaptive Gaussian-sum square-root cub... The paper deals with state estimation problem of nonlinear non-Gaussian discrete dynamic systems for improvement of accuracy and consistency. An efficient new algorithm called the adaptive Gaussian-sum square-root cubature Kalman filter(AGSSCKF) with a split-merge scheme is proposed. It is developed based on the squared-root extension of newly introduced cubature Kalman filter(SCKF) and is built within a Gaussian-sum framework. Based on the condition that the probability density functions of process noises and initial state are denoted by a Gaussian sum using optimization method, a bank of SCKF are used as the sub-filters to estimate state of system with the corresponding weights respectively, which is adaptively updated. The new algorithm consists of an adaptive splitting and merging procedure according to a proposed split-decision model based on the nonlinearity degree of measurement. The results of two simulation scenarios(one-dimensional state estimation and bearings-only tracking) show that the proposed filter demonstrates comparable performance to the particle filter with significantly reduced computational cost. 展开更多
关键词 Adaptive split-merge scheme Gaussian sum filter Nonlinear non-Gaussian State estimation squared-root cubature Kalman filter
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Newton, Halley, Pell and the Optimal Iterative High-Order Rational Approximation of √<span style='margin-left:-2px;margin-right:2px;border-top:1px solid black'>N</span>
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作者 Isaac Fried 《Applied Mathematics》 2018年第7期861-873,共13页
In this paper we examine single-step iterative methods for the solution of the nonlinear algebraic equation f (x) = x2 - N = 0 , for some integer N, generating rational approximations p/q that are optimal in the sense... In this paper we examine single-step iterative methods for the solution of the nonlinear algebraic equation f (x) = x2 - N = 0 , for some integer N, generating rational approximations p/q that are optimal in the sense of Pell’s equation p2 - Nq2 = k for some integer k, converging either alternatingly or oppositely. 展开更多
关键词 ITERATIVE methodS Super-Linear and Super-Quadratic methodS square roots Pell’s Equation OPTIMAL Rational Iterants root Bounds
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基于FFRLS和ASR-UKF滤波算法的锂电池SOC估计 被引量:1
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作者 邓丹 刘胜永 +2 位作者 王顺利 刘鹏辉 胡聪 《电源技术》 CAS 北大核心 2024年第2期299-305,共7页
锂电池在工作过程中,其内部参数易受多种因素影响,为提高锂电池在复杂环境下荷电状态(SOC)估计精度,以二阶戴维宁(Thevenin)等效模型为基础,结合遗忘因子递推最小二乘法(FFRLS)对模型参数进行在线辨识。针对传统卡尔曼滤波算法高度非线... 锂电池在工作过程中,其内部参数易受多种因素影响,为提高锂电池在复杂环境下荷电状态(SOC)估计精度,以二阶戴维宁(Thevenin)等效模型为基础,结合遗忘因子递推最小二乘法(FFRLS)对模型参数进行在线辨识。针对传统卡尔曼滤波算法高度非线性及系统噪声不确定性等缺点,提出了一种自适应平方根无迹卡尔曼滤波(ASR-UKF)算法,该算法利用平方根算法处理均值和协方差,确保了状态协方差的半正定性和稳定性,并引入自适应滤波算法对噪声进行实时修正,消除了系统时变噪声影响。结果表明,FFRLS能有效解决数据饱和及算法矩阵计算量大的问题,等效模型精度高达98%。在混合动力脉冲特性(HPPC)测试和北京公交动态测试工况(BBDST)下,ASR-UKF算法SOC估计最大误差分别为3.264%和0.572%,具备更好的跟踪效果,验证了改进算法良好的收敛性与自适应性。 展开更多
关键词 荷电状态 二阶Thevenin模型 遗忘因子递推最小二乘法 自适应平方根无迹卡尔曼滤波算法
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基于激光扫描仪的点云配准方法 被引量:1
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作者 褚海漫 程银宝 +3 位作者 李亚茹 罗哉 江文松 王燕 《计量学报》 CSCD 北大核心 2024年第3期433-439,共7页
针对激光扫描仪实际扫描得到的不完整点云配准困难问题,提出了一种基于对应点对的配准方法。通过激光扫描仪进行实验,得到被测工件的实测点云数据,基于Visual Studio软件配置Point Cloud Library环境,对实测模型与理想模型的点云配准进... 针对激光扫描仪实际扫描得到的不完整点云配准困难问题,提出了一种基于对应点对的配准方法。通过激光扫描仪进行实验,得到被测工件的实测点云数据,基于Visual Studio软件配置Point Cloud Library环境,对实测模型与理想模型的点云配准进行研究。首先对实测点云数据进行体素滤波以及均匀下采样的预处理;其次通过对应点对的方式进行对齐为后续精细配准提供较好的变换初值,后基于ICP算法实现点云配准精配准;最终以均方根误差作为点云配准精度评价指标对配准结果进行评价。借助CloudCompare软件对配准结果进行直观展示分析可知,在实测工件本身存在不绝对光滑的情况下,配准的均方根误差可控制在0.62 mm,表明该方法对于不完整点云的配准效果较好。 展开更多
关键词 几何量计量 激光扫描仪 点云配准 ICP算法 均方根误差
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含未知输入非线性系统的扩展平方根容积卡尔曼滤波算法
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作者 鹿子豪 王娜 +2 位作者 林崇 赵克友 董世桂 《科学技术与工程》 北大核心 2024年第14期5892-5900,共9页
针对工程实际应用中存在的未知输入会导致经典的非线性滤波器状态估计精度下降甚至滤波发散的问题,提出了一种基于最小方差无偏估计(minimum variance unbiased estimation,MVUE)准则的扩展平方根容积卡尔曼滤波(extended square-root c... 针对工程实际应用中存在的未知输入会导致经典的非线性滤波器状态估计精度下降甚至滤波发散的问题,提出了一种基于最小方差无偏估计(minimum variance unbiased estimation,MVUE)准则的扩展平方根容积卡尔曼滤波(extended square-root cubature Kalman filter,ESRCKF)算法。首先,结合上一时刻未知输入估计值对状态一步预测值进行修正,得到含未知输入条件下的状态预测值。其次,设计新息并采用加权最小二乘(weighted least squares,WLS)法获取当前时刻未知输入的无偏估计。最后,通过最小化协方差矩阵的迹,同时采用拉格朗日乘子法和舒尔补引理得到系统状态的最小方差无偏估计。仿真结果表明,相比于现有的非线性滤波算法,ESRCKF算法提高了在处理含未知输入非线性系统时的状态估计精度,并能同时实现系统状态和未知输入的最优估计,验证了该算法的有效性。 展开更多
关键词 平方根容积卡尔曼滤波 最小方差无偏估计 加权最小二乘法 状态估计 未知输入估计
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Ecoregional height-diameter models for Scots pine in Turkiye
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作者 Fadime Sağlam Oytun Emre Sakici 《Journal of Forestry Research》 SCIE EI CAS CSCD 2024年第6期49-61,共13页
Ecoregion-based height-diameter models were developed in the present study for Scots pine(Pinus sylves-tris L.)stands in Turkiye and included several ecological factors derived from a pre-existing ecoregional classifi... Ecoregion-based height-diameter models were developed in the present study for Scots pine(Pinus sylves-tris L.)stands in Turkiye and included several ecological factors derived from a pre-existing ecoregional classification system.The data were obtained from 2831 sample trees in 292 sample plots.Ten generalized height–diameter models were developed,and the best model(HD10)was selected according to statistical criteria.Then,nonlinear mixed-effects modeling was applied to the best model.The R2 for the generalized height‒diameter model(Richards function)modified by Sharma and Parton is 0.951,and the final model included number of trees,dominant height,and diameter at breast height,with a random parameter associated with each ecoregion attached to the inverse of the mean basal area.The full model predictions using the nonlinear mixed-effects model and the reduced model(HD10)predictions were compared using the nonlinear sum of extra squares test,which revealed significant differences between ecore-gions;ecoregion-based height–diameter models were thus found to be suitable to use.In addition,using these models in appropriate ecoregions was very important for achieving reliable predictions with low prediction errors. 展开更多
关键词 Tree height Nonlinear mixed-effects modelling Nonlinear sum of extra squares method ECOREGION Scots pine
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基于图像的目标姿态计算精度分析方法
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作者 张兵 黄剑 《航天技术与工程学报》 2024年第3期91-97,共7页
为支撑运动目标姿态计算的需求分析、功能设计、精度分析,本文采用基于数论法的空间目标姿态计算精度分析方法,针对目标图像的像素提取标准差、成像分辨率、成像焦距、目标大小等影响因素,利用数论法中的好格子点法模拟目标图像的像素... 为支撑运动目标姿态计算的需求分析、功能设计、精度分析,本文采用基于数论法的空间目标姿态计算精度分析方法,针对目标图像的像素提取标准差、成像分辨率、成像焦距、目标大小等影响因素,利用数论法中的好格子点法模拟目标图像的像素位置并提取随机误差,利用目标成像提取的平行线来计算法线指向矢量,奇异值分解法线指向矩阵求取平行线指向作为对应方向目标姿态指向,统计标准差作为目标姿态计算误差。在像素提取标准差为0.1 px、成像分辨率为8μm、成像焦距为6 m、目标大小为20 m等成像数据条件下,目标姿态计算均方根误差能够小于10°。经数值仿真验证,该方法可有效支撑基于图像的目标姿态计算与精度分析。 展开更多
关键词 目标姿态 数论法 好格子点法 均方根误差
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基于均方根容积卡尔曼滤波的船舶操纵运动响应模型参数辨识
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作者 李晴昊 任俊生 华焱 《系统仿真学报》 CAS CSCD 北大核心 2024年第8期1790-1799,共10页
为了解决扩展卡尔曼滤波(extended Kalman filter,EKF)算法在船舶操纵运动模型参数辨识中存在辨识精度低、稳定性差和泛化能力弱的问题,提出了一种基于均方根容积卡尔曼滤波(square root cubature Kalman filter,SRCKF)的辨识算法。在CK... 为了解决扩展卡尔曼滤波(extended Kalman filter,EKF)算法在船舶操纵运动模型参数辨识中存在辨识精度低、稳定性差和泛化能力弱的问题,提出了一种基于均方根容积卡尔曼滤波(square root cubature Kalman filter,SRCKF)的辨识算法。在CKF框架下将方差矩阵的均方根代替原始方差矩阵,使用三角分解对其进行预测和更新以提高辨识的稳定性。将EKF作为对比算法,利用四阶龙格库塔法解算的数值仿真数据,对舵角符合舵机伺服机构变化的船舶二阶非线性响应模型参数进行辨识,并将得到的辨识模型开展泛化能力验证试验。结果表明:SRCKF算法具有比EKF算法更高的辨识精度、稳定性和泛化能力。 展开更多
关键词 参数辨识 SRCKF(square root cubature Kalman filter) 四阶龙格库塔法 舵机伺服机构 响应模型
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面向粒子图像测速的光流金字塔插值优化方法
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作者 单良 简娟 +4 位作者 熊俊哲 施飞杨 洪波 楼晓颖 孔明 《光子学报》 EI CAS CSCD 北大核心 2024年第3期153-166,共14页
提出了一种面向粒子图像测速的光流金字塔插值优化方法,可以减小重建角度误差和均方根误差,尤其是图像边缘部分的角度误差。使用该优化算法分别对单涡流、双涡流、DNS湍流粒子场进行速度场重建,得到三种流场的均方根误差和平均角度误差... 提出了一种面向粒子图像测速的光流金字塔插值优化方法,可以减小重建角度误差和均方根误差,尤其是图像边缘部分的角度误差。使用该优化算法分别对单涡流、双涡流、DNS湍流粒子场进行速度场重建,得到三种流场的均方根误差和平均角度误差比优化前至少降低了15.96%和19.87%。搭建二维PIV实验系统,在待测流场中均匀撒入100μm的PSP粒子,进行旋转实验和注水实验,分别模拟涡流场和射流场,所提出的优化算法可以获得与常见算法流形一致的速度场。 展开更多
关键词 粒子图像测速 光流法 均方根误差 平均角度误差 图像插值 流体测量 速度场重建
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全日制中学宿舍建筑生活给水系统设计探讨
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作者 韦慧 《科技资讯》 2024年第8期164-167,共4页
某全日住宿制中学宿舍居室内设卫生间,根据《建筑给水排水设计标准》(GB 50015—2019)第3.7.6条平方根法计算生活给水设计秒流量,实际使用中存在顶层供水压力不足,流量偏小的现象。根据全日住宿制中学的作息特点进行分析,找出生活给水... 某全日住宿制中学宿舍居室内设卫生间,根据《建筑给水排水设计标准》(GB 50015—2019)第3.7.6条平方根法计算生活给水设计秒流量,实际使用中存在顶层供水压力不足,流量偏小的现象。根据全日住宿制中学的作息特点进行分析,找出生活给水设计秒流量与高峰实际用水流量存在差别的原因。并针对全日住宿制中学宿舍生活给水系统提出系统优化意见。 展开更多
关键词 全日住宿制中学宿舍 生活给水系统 定额法 平方根法
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