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A Gauss-Newton Approach for Nonlinear Optimal Control Problem with Model-Reality Differences
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作者 Sie Long Kek Jiao Li +1 位作者 Wah June Leong Mohd Ismail Abd Aziz 《Open Journal of Optimization》 2017年第3期85-100,共16页
Output measurement for nonlinear optimal control problems is an interesting issue. Because the structure of the real plant is complex, the output channel could give a significant response corresponding to the real pla... Output measurement for nonlinear optimal control problems is an interesting issue. Because the structure of the real plant is complex, the output channel could give a significant response corresponding to the real plant. In this paper, a least squares scheme, which is based on the Gauss-Newton algorithm, is proposed. The aim is to approximate the output that is measured from the real plant. In doing so, an appropriate output measurement from the model used is suggested. During the computation procedure, the control trajectory is updated iteratively by using the Gauss-Newton recursion scheme. Consequently, the output residual between the original output and the suggested output is minimized. Here, the linear model-based optimal control model is considered, so as the optimal control law is constructed. By feed backing the updated control trajectory into the dynamic system, the iterative solution of the model used could approximate to the correct optimal solution of the original optimal control problem, in spite of model-reality differences. For illustration, current converted and isothermal reaction rector problems are studied and the results are demonstrated. In conclusion, the efficiency of the approach proposed is highly presented. 展开更多
关键词 NONLINEAR Optimal Control Gauss-newton APPROACH ITERATIVE Procedure Output Error model-Reality DIFFERENCES
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基于Newton插值法高维代理模型的结构有限元模型修正
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作者 卢祯辉 钱嘉伟 欧阳启东 《建筑技术》 2025年第21期2665-2668,共4页
为了优化基于设计图纸建立的结构有限元模型,得到结构的基准有限元模型,提出了一种基于牛顿插值法的高维模型表示(High-dimensional Model representation based on Newton Interpolation, NEWTHDMR)的结构有限元模型修正方法。NEWT-HDM... 为了优化基于设计图纸建立的结构有限元模型,得到结构的基准有限元模型,提出了一种基于牛顿插值法的高维模型表示(High-dimensional Model representation based on Newton Interpolation, NEWTHDMR)的结构有限元模型修正方法。NEWT-HDMR可以描述结构参数与响应之间的黑箱函数关系以取代有限元软件,联合结构真实响应残差和构造目标函数;结合Jaya算法,通过迭代求解结构待修正参数的修正值,进而修正结构有限元模型。利用简支梁数值模型验证本文提出方法的有效性,并分析对比一阶NEWT–HDMR和二阶NEWT-HDMR在修正精度上的差异。结果表明,NEWT-HDMR模型修正结果可以满足工程要求且二阶NEWT-HDMR修正精度更高,验证该方法在结构有限元模型修正中应用的可行性和可靠性。 展开更多
关键词 有限元模型修正 高维模型表示 Jaya算法 牛顿插值法
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改进的6-DOF并联机器人Newton-Euler动力学模型 被引量:23
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作者 韩佩富 王常武 +2 位作者 孔令富 黄真 赵立强 《机器人》 EI CSCD 北大核心 2000年第4期315-318,共4页
本文在 6 - DOF并联机器人运动模型的基础上 ,采用对加速度及作用力正交分解的方法 ,将其 Newton- Euler动力学模型归结为一个简单的、可用于实时计算的模型 .
关键词 并联机器人 newton-Euler动力学模型 液压缸
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基于Newton法优化ARMA模型参数的船舶升沉运动预测研究 被引量:15
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作者 唐刚 姚小强 胡雄 《海洋工程》 CSCD 北大核心 2020年第2期27-38,共12页
为解决波浪补偿系统中时延现象导致的控制性能下降问题,通过建立Newton-ARMA模型提前预测船舶升沉运动来消除时延现象。首先设计卡尔曼滤波器对船舶升沉运动加速度信号进行降噪滤波处理;然后使用加速度二次积分模块将加速度信号转换为... 为解决波浪补偿系统中时延现象导致的控制性能下降问题,通过建立Newton-ARMA模型提前预测船舶升沉运动来消除时延现象。首先设计卡尔曼滤波器对船舶升沉运动加速度信号进行降噪滤波处理;然后使用加速度二次积分模块将加速度信号转换为位移信号;最后建立自回归滑动平均(ARMA)模型,并使用牛顿(Newton)法对模型参数进行优化,得到船舶升沉运动的Newton-ARMA预测模型。仿真结果表明,Newton-ARMA模型对船舶升沉运动的预测时间可达10 s,预测误差随着预测时间的增加而增大;Newton-ARMA模型对二级海况、三级海况和四级海况下的船舶升沉运动平均预测精度分别达到89.43%、88.53%以及87.78%,远高于ARMA模型对船舶升沉运动预测的精度,说明采用Newton法优化ARMA模型参数可以显著提高船舶升沉运动的预测精度,也即Newton-ARMA模型对控制波浪补偿系统时延具有较好的补偿效果。 展开更多
关键词 运动预测 newton-ARMA模型 卡尔曼滤波器 加速度二次积分 时延
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非线性信道的LMS Newton均衡算法的研究 被引量:5
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作者 刘顺兰 蒋树南 《电路与系统学报》 CSCD 北大核心 2011年第1期108-115,共8页
本文使用Hammerstein模型和维纳模型代替Volterra级数模型来模拟非线性结构以降低运算复杂度,提出了一个由Hammerstein模型和维纳模型构建成的非线性信道传输系统的模型,由此模型给出并推导出了基于该信道模型的NCLMS算法、改进1型NCLMS... 本文使用Hammerstein模型和维纳模型代替Volterra级数模型来模拟非线性结构以降低运算复杂度,提出了一个由Hammerstein模型和维纳模型构建成的非线性信道传输系统的模型,由此模型给出并推导出了基于该信道模型的NCLMS算法、改进1型NCLMS Newton算法和改进2型NCLMS Newton算法。仿真结果表明,NCLMS算法收敛速度慢且性能不稳定;改进1型NCLMS Newton算法克服了NCLMS算法收敛速度慢的缺点并提高了算法的稳定性;改进2型NCLMS Newton算法在继承了改进1型NCLMS Newton算法的优点之上进一步提高了算法的收敛速度,逼近理想NCLMS Newton算法。 展开更多
关键词 非线性信道 HAMMERSTEIN模型 维纳模型 牛顿算法 LMS算法
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Aircraft Modeling and Simulation with Cargo Moving Inside 被引量:22
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作者 陈杰 史忠科 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2009年第2期191-197,共7页
Cargo airdrop has long been one of the most important measures to deal with urgent immediate needs, such as providing as- sists in military operations and sending relief to disaster areas, just to name a few. Because ... Cargo airdrop has long been one of the most important measures to deal with urgent immediate needs, such as providing as- sists in military operations and sending relief to disaster areas, just to name a few. Because it is carried out during flight, it is necessary to investigate the influences of the drop process on flight characteristics to ensure successful execution of the task. This article mainly studies the modeling of flight systems in large flying transport planes with cargo moving in it. By buildi... 展开更多
关键词 modelS dynamics equation newton’s second law AIRDROP cargo moving
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基于Newton-Raphson法的多效顺流蒸发系统的模拟 被引量:2
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作者 徐建良 《现代化工》 CAS CSCD 北大核心 2011年第4期87-91,共5页
建立了普通、复杂顺流蒸发系统的数学模型,采用Newton-Raphson法求解,应用面向对象的Pascal语言编制了该算法的计算程序,可对二至七效常规和复杂并流蒸发系统进行模拟计算。以蔗糖溶液为例,对三效并流的5种流程进行了计算和比较,结果表... 建立了普通、复杂顺流蒸发系统的数学模型,采用Newton-Raphson法求解,应用面向对象的Pascal语言编制了该算法的计算程序,可对二至七效常规和复杂并流蒸发系统进行模拟计算。以蔗糖溶液为例,对三效并流的5种流程进行了计算和比较,结果表明将各效冷凝液全部用于预热原料的多效蒸发流程能耗最低,蒸发器面积最小。 展开更多
关键词 多效蒸发 数学模型 newton-Raphson法 顺流流程 模拟计算
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Newton-PCG复合算法在饱和砂土边坡液化数值模拟中的应用
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作者 黄林冲 徐志胜 +1 位作者 黄建陵 周翠英 《岩土工程学报》 EI CAS CSCD 北大核心 2009年第11期1717-1722,共6页
引入Newton-PCG算法,编制了算法程序,建立了流–固耦合砂土模型,实现了饱和砂土边坡液化问题的有限元数值模拟。采用一次牛顿步,和多步预条件共轭梯度子迭代的Newton-PCG复合算法,编制了算法的FORTRAN语言程序。基于临界状态塑性模型框... 引入Newton-PCG算法,编制了算法程序,建立了流–固耦合砂土模型,实现了饱和砂土边坡液化问题的有限元数值模拟。采用一次牛顿步,和多步预条件共轭梯度子迭代的Newton-PCG复合算法,编制了算法的FORTRAN语言程序。基于临界状态塑性模型框架,给出了饱和状态下砂土固–液耦合模型的本构关系,再现了某饱和砂土边坡液化的力学状态,探讨了水压力分布与流动特性。结果表明:Newton-PCG算法能更有效地进行大规模非线性求解;建立的模型能较好地反映砂土–流体耦合状态下的力学行为;多孔介质中由于流体的流动,孔隙水压力对砂土液化的力学行为影响较大,在局部剪切带即将形成的区域,水压力值明显增大,而且方向指向剪切带的外法线方向;根据液化发生准则,画出了边坡发生液化的滑动面,对于预测边坡的发生具有重要的现实意义。 展开更多
关键词 newton-PCG 砂土 本构模型 液化 算法
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一种改进的Stewart平台Newton-Euler动力学模型 被引量:4
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作者 何兆麒 薛冬新 +1 位作者 张娟 宋希庚 《振动与冲击》 EI CSCD 北大核心 2018年第9期221-229,共9页
原有运用Newton-Euler法建立的6-UPS(Universal-Prismatic-Spherical)Stewart平台的经典闭环动力学模型存在一些不足,逐渐有学者从三个方面改进,即建模过程中考虑支杆绕自身轴线的旋转自由度,修正万向铰约束力矩的方向,应用平行轴定理... 原有运用Newton-Euler法建立的6-UPS(Universal-Prismatic-Spherical)Stewart平台的经典闭环动力学模型存在一些不足,逐渐有学者从三个方面改进,即建模过程中考虑支杆绕自身轴线的旋转自由度,修正万向铰约束力矩的方向,应用平行轴定理计算各结构的转动惯量。在此基础上,考虑到上、下支杆关于下铰接点的力矩平衡属于不同情况,选择合理形式的动量矩定理建立支杆及上平台的欧拉方程,并结合前三点最终得到两种闭环动力学改进模型。使用相同的算例,比较改进模型和原模型的动态响应的不同,说明改进模型的必要性。从理论推导的角度来看,改进的模型比原模型更加合理、准确。 展开更多
关键词 6-UPS STEWART平台 改进动力学模型 newton-Euler法
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基于交叉梯度结构约束的可控源电磁法反演研究
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作者 安红颖 岳云宝 +3 位作者 郭长安 陈楚桐 李阳铭 王堃鹏 《物探化探计算技术》 2026年第1期107-116,共10页
可控源电磁法在地质勘探中发挥着重要作用,然而其探测效果仍然具有一定的局限性。为增加可控源电磁法对于地下异常体的结构约束,可以引入更多结构信息约束反演过程,从而降低可控源电磁法的多解性。笔者基于交叉梯度法引入了在可控源电... 可控源电磁法在地质勘探中发挥着重要作用,然而其探测效果仍然具有一定的局限性。为增加可控源电磁法对于地下异常体的结构约束,可以引入更多结构信息约束反演过程,从而降低可控源电磁法的多解性。笔者基于交叉梯度法引入了在可控源电磁法反演过程中加入速度模型进行结构约束的方法。为了验证方法的有效性,笔者首先建立两个简单理论模型,对其进行三维正反演研究,选择有限内存拟牛顿法(LBFGS)对模型的合成数据进行可控源电磁法的常规反演和交叉梯度反演对比研究。其次,笔者利用甘肃花牛山某铅锌矿电性模型进一步开展了复杂结构的约束反演。笔者的研究表明,基于交叉梯度结构约束的可控源反演方法能够提高地下异常体可靠性,验证了该方法在复杂地下地质情况的有效性。 展开更多
关键词 可控源电磁法 交叉梯度 速度结构 有限内存拟牛顿法(LBFGS) 三维正反演
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基于Newton-Raphson功率不匹配的电流注入潮流控制
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作者 梁康有 袁玲 谭宇航 《控制工程》 CSCD 北大核心 2017年第7期1467-1472,共6页
为进一步简化电流注入潮流控制补偿方法,利用Newton-Raphson功率不匹配方法构建功率不匹配的电流注入潮流控制方法。该方法基于STATCOM总线控制网络,并利用压控总线与零功率产生所需的电压幅值作为控制指标。STATCOM的连接总线功率不匹... 为进一步简化电流注入潮流控制补偿方法,利用Newton-Raphson功率不匹配方法构建功率不匹配的电流注入潮流控制方法。该方法基于STATCOM总线控制网络,并利用压控总线与零功率产生所需的电压幅值作为控制指标。STATCOM的连接总线功率不匹配方程包含在Newton-Raphson电流注入潮流方程,以及其他PQ总线的电流匹配方程中。此外,利用最终的目标值在迭代过程中对STATCOM的参数进行更新。通过该总线发电方式,可减少所需的方程数目。开发的模型降低了计算机程序代码的复杂性,避免Jacobian矩阵修改,并提高可重用性。最后,对所研制的STATCOM模型的性能,使用标准IEEE测试系统进行验证。 展开更多
关键词 newton—Raphson迭代 注入电流 功率不匹配 STATCOM模型 Jacobian矩阵
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Rotorcraft with a 3DOF Rigid Manipulator:Quaternion-based Modeling and Real-time Control Tolerant to Multi-body Couplings 被引量:4
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作者 J.Alvarez-Munoz N.Marchand +3 位作者 J.F.Guerrero-Castellanos J.J.Tellez-Guzman J.Escareno M.Rakotondrabe 《International Journal of Automation and computing》 EI CSCD 2018年第5期547-558,共12页
This paper proposes a simple solution for the stabilization of a mini-quadcopter carrying a 3DoF(degrees of freedom) manipulator robot in order to enhance its achievable workspace and application profile. Since the ... This paper proposes a simple solution for the stabilization of a mini-quadcopter carrying a 3DoF(degrees of freedom) manipulator robot in order to enhance its achievable workspace and application profile. Since the motion of the arm induces torques which degrade the stability of the system, in the present work, we consider the stabilization of both subsystems: the quadcopter and the robotic arm. The mathematical model of the system is based on quaternions. Likewise, an attitude control law consisting of a bounded quaternion-based feedback stabilizes the quadcopter to a desired attitude while the arm is evolving. The next stage is the translational dynamics which is simplified for control(nonlinear) design purposes. The aforementioned controllers are based on saturation functions whose stability is explicitly proved in the Lyapunov sense. Finally, experimental results and a statistical study validate the proposed control strategy. 展开更多
关键词 Observer-based control quaternion and newton-Euler modeling bounded-input control aerial manipulator disturbancerejection.
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Statistical Inference in Generalized Linear Mixed Models by Joint Modelling Mean and Covariance of Non-Normal Random Effects
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作者 Yin Chen Yu Fei Jianxin Pan 《Open Journal of Statistics》 2015年第6期568-584,共17页
Generalized linear mixed models (GLMMs) are typically constructed by incorporating random effects into the linear predictor. The random effects are usually assumed to be normally distributed with mean zero and varianc... Generalized linear mixed models (GLMMs) are typically constructed by incorporating random effects into the linear predictor. The random effects are usually assumed to be normally distributed with mean zero and variance-covariance identity matrix. In this paper, we propose to release random effects to non-normal distributions and discuss how to model the mean and covariance structures in GLMMs simultaneously. Parameter estimation is solved by using Quasi-Monte Carlo (QMC) method through iterative Newton-Raphson (NR) algorithm very well in terms of accuracy and stabilization, which is demonstrated by real binary salamander mating data analysis and simulation studies. 展开更多
关键词 Generalized Linear Mixed models MULTIVARIATE t DISTRIBUTION MULTIVARIATE Mixture NORMAL DISTRIBUTION Quasi-Monte Carlo newton-RAPHSON Joint modelling of Mean and COVARIANCE
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Rotating Lepton Model of Pions and Kaons: Mechanics at fm Distances
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作者 Constantinos G. Vayenas Dionysios Tsousis +2 位作者 Dimitrios Grigoriou Konstantinos Parisis Elias C. Aifantis 《Journal of Applied Mathematics and Physics》 2022年第9期2805-2819,共15页
The present article is a continuation of a recently published paper [1] in which we have modeled the composition and structure of neutrons and other hadrons using the Rotating Lepton Model (RLM) which is a Bohr type m... The present article is a continuation of a recently published paper [1] in which we have modeled the composition and structure of neutrons and other hadrons using the Rotating Lepton Model (RLM) which is a Bohr type model employing the relativistic gravitational attraction between three ultrafast rotating neutrinos as the centripetal force. The RLM accounts for special relativity and also for the De Broglie equation of quantum mechanics. In this way this force was shown to reach the value of the Strong Force while the values of the masses of the rotating relativistic neutrinos reach those of quarks. Masses computed for twelve hadrons and bosons are in very close (~2%) agreement with the experimental values. Here we use the same RLM approach to describe the composition and structure and to compute the masses of Pions and Kaons which are important zero spin mesons. Contrary to hadrons and bosons which have been found via the RLM to comprise the heaviest neutrino eigenmass m<sub>3</sub>, in the case of mesons the intermediate neutrino mass eigenstate m<sub>2</sub> is found to play the dominant role. This can explain why the lowest masses of mesons are generally smaller than those of hadrons and bosons. Thus in the case of Pions it is found that they comprise three rotating m<sub>2</sub> mass eigenstate neutrinos and the computed mass of 136.6 MeV/c<sup>2</sup> is in good agreement with the experimental value of 134.977 MeV/c<sup>2</sup>. The Kaon structure is found to consist of six m<sub>2</sub> mass eigenstate neutrinos arranged in two parallel pion-type rotating triads. The computed Kaon mass differs less that 2% from the experimental K<sup>±</sup> and K&#176;values of 493.677 MeV/c<sup>2</sup> and 497.648 MeV/c<sup>2</sup> respectively. This, in conjunction with the experimentally observed decay products of the Kaons, provides strong support for the proposed K structure. 展开更多
关键词 Pions and Kaons-Structure and Masses Gravitational Bohr-de Broglie-newton-Einstein Type models Rotating Lepton model (RLM) HADRONIZATION Neutrino Masses Special Relativity Gravitational Force Quantum Mechanics
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Modelling and Assessment of Survival Probability of Shock Model with Two Kinds of Shocks
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作者 Surekha B. Munoli Suhas   《Open Journal of Statistics》 2019年第4期484-493,共10页
The study aims at modelling and assessment of survival probability of a component experiencing two kinds of shocks namely, damage shock and fatal shock. Shocks are occurring randomly in time as events of a Poisson Pro... The study aims at modelling and assessment of survival probability of a component experiencing two kinds of shocks namely, damage shock and fatal shock. Shocks are occurring randomly in time as events of a Poisson Process. The two cases of fixed/random threshold of components are studied. Survival probabilities of proposed models are derived. Maximum likelihood estimators (MLEs) of survival probabilities are obtained using the data from life testing experiments. Fisher information and asymptotic distribution of MLEs of parameters are obtained when a constant threshold is considered. Computation and comparison of estimators of two cases (constant threshold and random threshold) are made through simulation studies. The study recommends the consideration of threshold as a random variable. 展开更多
关键词 DAMAGES Life Testing Experiment newton-RAPHSON Method POISSON Process Shock models SURVIVAL PROBABILITY
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Rheology-based facial animation realistic face model
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作者 曾丹 裴丽 《Journal of Shanghai University(English Edition)》 CAS 2009年第6期423-427,共5页
This paper presents a rheology-based approach to animate realistic face model. The dynamic and biorheological characteristics of the force member (muscles) and stressed member (face) are considered. The stressed f... This paper presents a rheology-based approach to animate realistic face model. The dynamic and biorheological characteristics of the force member (muscles) and stressed member (face) are considered. The stressed face can be modeled as viscoelastic bodies with the Hooke bodies and Newton bodies connected in a composite series-parallel manner. Then, the stress-strain relationship is derived, and the constitutive equations established. Using these constitutive equations, the face model can be animated with the force generated by muscles. Experimental results show that this method can realistically simulate the mechanical properties and motion characteristics of human face, and performance of this method is satisfactory. 展开更多
关键词 facial mechanical model viscoelastic model stress-strain relationship Hooke body newton body
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基于非线性模型预测控制的拖挂车系统泊车轨迹规划方法
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作者 杨毅 贾博铂 +2 位作者 高亮 李岱伟 谢杉杉 《中国惯性技术学报》 北大核心 2025年第2期179-188,共10页
拖挂车是欠驱动与非完整约束高度耦合的非线性系统,具有状态维度高、约束复杂、内部稳定性差等特点,导致其泊车轨迹规划的求解时间长。因此,设计了一种基于非线性模型预测控制的拖挂车泊车轨迹规划方法,通过融合系统多元约束,构建优化问... 拖挂车是欠驱动与非完整约束高度耦合的非线性系统,具有状态维度高、约束复杂、内部稳定性差等特点,导致其泊车轨迹规划的求解时间长。因此,设计了一种基于非线性模型预测控制的拖挂车泊车轨迹规划方法,通过融合系统多元约束,构建优化问题,规划无碰撞的泊车轨迹。为加速优化问题的求解,首先,在系统的高维状态空间中使用结合Reed-Shepp(RS)曲线的改进快速扩展随机树(RRT*-RS)进行随机采样,以RS曲线满足反向行驶的特性,找到一条近似最优路径作为优化问题热启动的参考解。然后,在求解优化问题时,选用近似平均牛顿法以节约求解时间,提升系统实时性。最后,进行了倒库泊车、侧方泊车、多障碍物等场景实验仿真验证,仿真结果表明所提方法在不同场景下均可实现拖挂车泊车快速轨迹规划,求解时间与传统内点法和序列二次规划法相比均有40%以上的提升。 展开更多
关键词 拖挂车系统 自主泊车 轨迹规划 非线性模型预测控制 近似平均牛顿法
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Q-Theory: A Connection between Newton’s Law and Coulomb’s Law? 被引量:1
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作者 Christopher Pilot 《Journal of High Energy Physics, Gravitation and Cosmology》 2021年第2期632-660,共29页
Assuming a Winterberg model for space where the vacuum consists of a very stiff two-component superfluid made up of positive and negative mass planckions, Q theory is the hypothesis, that Planck charge, <i>q<... Assuming a Winterberg model for space where the vacuum consists of a very stiff two-component superfluid made up of positive and negative mass planckions, Q theory is the hypothesis, that Planck charge, <i>q<sub>pl</sub></i>, was created at the same time as Planck mass. Moreover, the repulsive force that like-mass planckions experience is, in reality, due to the electrostatic force of repulsion between like charges. These forces also give rise to what appears to be a gravitational force of attraction between two like planckions, but this is an illusion. In reality, gravity is electrostatic in origin if our model is correct. We determine the spring constant associated with planckion masses, and find that, <img src="Edit_770c2a48-039c-4cc9-8f66-406c0cfc565c.png" width="90" height="15" alt="" />, where <i>ζ</i>(3) equals Apery’s constant, 1.202 …, and, <i>n</i><sub>+</sub>(0)=<i>n</i>_(0), is the relaxed, <i>i.e.</i>, <img src="Edit_813d5a6f-b79a-49ba-bdf7-5042541b58a0.png" width="25" height="12" alt="" />, number density of the positive and negative mass planckions. In the present epoch, we estimate that, <i>n</i><sub>+</sub>(0) equals, 7.848E54 m<sup>-3</sup>, and the relaxed distance of separation between nearest neighbor positive, or negative, planckion pairs is, <i>l</i><sub>+</sub>(0)=<i>l</i><sub>_</sub>(0)=5.032E-19 meters. These values were determined using box quantization for the positive and negative mass planckions, and considering transitions between energy states, much like as in the hydrogen atom. For the cosmos as a whole, given a net smeared macroscopic gravitational field of, <img src="Edit_efc8003d-5297-4345-adac-4ac95536934d.png" width="80" height="15" alt="" />, due to all the ordinary, and bound, matter contained within the observable universe, an average displacement from equilibrium for the planckion masses is a mere 7.566E-48 meters, within the vacuum made up of these particles. On the surface of the earth, where, <i>g</i>=9.81m/s<sup>2</sup>, the displacement amounts to, 7.824E-38 meters. All of these displacements are due to increased gravitational pressure within the vacuum, which in turn is caused by applied gravitational fields. The gravitational potential is also derived and directly related to gravitational pressure. 展开更多
关键词 Extended Gravity Winterberg model Planckion Mass Theory Modified Quantum Vacuum Planck Charge newton’s Law Coulomb’s Law Dark Energy
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基于四阶Newton-Cotes公式优化背景值的灰色自记忆模型研究及应用
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作者 张高锋 马艳 +2 位作者 程龙 苟耀峰 孙小敏 《西北水电》 2021年第6期22-25,共4页
科学合理的预测经济社会发展用水需求,是地区水资源规划的基础和前提。针对现有需水预测方法计算成果往往与实际存在一定的差距,本文从需水预测的灰色特性出发,通过采用四阶Newton-Cotes求积公式对灰色微分方程背景值进行优化,在此基础... 科学合理的预测经济社会发展用水需求,是地区水资源规划的基础和前提。针对现有需水预测方法计算成果往往与实际存在一定的差距,本文从需水预测的灰色特性出发,通过采用四阶Newton-Cotes求积公式对灰色微分方程背景值进行优化,在此基础上建立基于四阶Newton-Cotes求积公式优化背景值的灰色自记忆模型,并在城市用水预测中加以应用。实例研究表明,该模型预测精度较高,可作为城市需水量预测的依据。 展开更多
关键词 newton-COTES求积公式 背景值优化 灰色自记忆模型 需水量预测
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基于强稳定收敛的偏正态联合位置与尺度模型的参数估计算法
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作者 薛潇 吴刘仓 《应用数学》 北大核心 2025年第1期201-210,共10页
传统的迭代算法(例如牛顿算法,EM算法等)在实际应用中,往往存在初始值较为敏感的问题.为解决这一问题,一种强稳定的收敛算法——Upper-crossing/Solution算法(以下称US算法)被提出,这种算法虽然在求解一元非线性函数时具有强稳定性,但... 传统的迭代算法(例如牛顿算法,EM算法等)在实际应用中,往往存在初始值较为敏感的问题.为解决这一问题,一种强稳定的收敛算法——Upper-crossing/Solution算法(以下称US算法)被提出,这种算法虽然在求解一元非线性函数时具有强稳定性,但是不能推广到多元的情形.那么针对多元情形,本文将结合偏正态分布的随机表示,对偏正态联合位置与尺度模型的似然函数进行分层,并且利用MM算法得到一元的情形,再使用US算法构造强稳定的收敛算法.最后通过随机模拟分析和实例分析研究表明了US算法较牛顿迭代法大大降低了算法对初值的敏感度以及显著地提高了收敛的稳定性. 展开更多
关键词 偏正态联合位置与尺度模型 牛顿迭代法 US算法 强稳定收敛
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