期刊文献+
共找到3,106篇文章
< 1 2 156 >
每页显示 20 50 100
Simulation of Steel Reinforcement on the Nonlinear Behaviour of Slender Glulam Beam Columns by Using the Newton-Raphson Method
1
作者 Martial Ourmama Marcelline Blanche Manjia Edmond Dawak Fezeu 《Open Journal of Applied Sciences》 2024年第2期243-266,共24页
The current theory in NF EN 1995-1-1/NA of Eurocode 5, which is based on maximum deflection, has been investigated on softwoods. Therefore, this theory is not adapted for slender glulam beam columns made of tropical h... The current theory in NF EN 1995-1-1/NA of Eurocode 5, which is based on maximum deflection, has been investigated on softwoods. Therefore, this theory is not adapted for slender glulam beam columns made of tropical hardwood species from the Congo Basin. This maximum deflection is caused by a set of loads applied to the structure. However, Eurocode 5 doesn’t provide how to predict this deflection in case of long-term load for such structures. This can be done by studying load-displacement (P-Δ) behaviour of these structures while taking into account second order effects. To reach this goal, a nonlinear analysis has been performed on a three-dimensional beam column embedded on both ends. Since conducting experimental investigations on large span structural products is time-consuming and expensive especially in developing countries, a numerical model has been implemented using the Newton-Raphson method to predict load-displacement (P-Δ) curve on a slender glulam beam column made of tropical hardwood species. On one hand, the beam has been analyzed without wood connection. On the other hand, the beam has been analyzed with a bolted wood connection and a slotted-in steel plate. The load cases considered include self-weight and a uniformly applied long-term load. Combinations of serviceability limit states (SLS) and ultimate limit states (ULS) have also been considered, among other factors. A finite-element software RFEM 5 has been used to implement the model. The results showed that the use of steel can reduce displacement by 20.96%. Additionally, compared to the maximum deflection provided by Eurocode 5 for softwoods, hardwoods can exhibit an increasing rate of 85.63%. By harnessing the plastic resistance of steel, the bending resistance of wood can be increased by 32.94%. 展开更多
关键词 Nonlinear Analysis newton-Raphson method Maximum Deflection Bolted Wood Connection Hardwood Species
下载PDF
A Distributed Newton Method for Processing Signals Defined on the Large-Scale Networks
2
作者 Yanhai Zhang Junzheng Jiang +1 位作者 Haitao Wang Mou Ma 《China Communications》 SCIE CSCD 2023年第5期315-329,共15页
In the graph signal processing(GSP)framework,distributed algorithms are highly desirable in processing signals defined on large-scale networks.However,in most existing distributed algorithms,all nodes homogeneously pe... In the graph signal processing(GSP)framework,distributed algorithms are highly desirable in processing signals defined on large-scale networks.However,in most existing distributed algorithms,all nodes homogeneously perform the local computation,which calls for heavy computational and communication costs.Moreover,in many real-world networks,such as those with straggling nodes,the homogeneous manner may result in serious delay or even failure.To this end,we propose active network decomposition algorithms to select non-straggling nodes(normal nodes)that perform the main computation and communication across the network.To accommodate the decomposition in different kinds of networks,two different approaches are developed,one is centralized decomposition that leverages the adjacency of the network and the other is distributed decomposition that employs the indicator message transmission between neighboring nodes,which constitutes the main contribution of this paper.By incorporating the active decomposition scheme,a distributed Newton method is employed to solve the least squares problem in GSP,where the Hessian inverse is approximately evaluated by patching a series of inverses of local Hessian matrices each of which is governed by one normal node.The proposed algorithm inherits the fast convergence of the second-order algorithms while maintains low computational and communication cost.Numerical examples demonstrate the effectiveness of the proposed algorithm. 展开更多
关键词 graph signal processing distributed newton method active network decomposition secondorder algorithm
下载PDF
Numerical Methods for a Class of Quadratic Matrix Equations
3
作者 GUAN Jinrui WANG Zhixin SHAO Rongxia 《应用数学》 北大核心 2024年第4期962-970,共9页
Quadratic matrix equations arise in many elds of scienti c computing and engineering applications.In this paper,we consider a class of quadratic matrix equations.Under a certain condition,we rst prove the existence of... Quadratic matrix equations arise in many elds of scienti c computing and engineering applications.In this paper,we consider a class of quadratic matrix equations.Under a certain condition,we rst prove the existence of minimal nonnegative solution for this quadratic matrix equation,and then propose some numerical methods for solving it.Convergence analysis and numerical examples are given to verify the theories and the numerical methods of this paper. 展开更多
关键词 Quadratic matrix equation M-MATRIX Minimal nonnegative solution newton method Bernoulli method
下载PDF
Weighted Variational Minimization Model for Wavelet Domain Inpainting with Primal-Dual Method
4
作者 许建楼 郝岩 +1 位作者 郝彬彬 张凤云 《Journal of Donghua University(English Edition)》 EI CAS 2014年第4期458-462,共5页
To preserve the edges and details of the image,a new variational model for wavelet domain inpainting was proposed which contained a non-convex regularizer. The non-convex regularizer can utilize the local information ... To preserve the edges and details of the image,a new variational model for wavelet domain inpainting was proposed which contained a non-convex regularizer. The non-convex regularizer can utilize the local information of image and perform better than those usual convex ones. In addition, to solve the non-convex minimization problem,an iterative reweighted method and a primaldual method were designed. The numerical experiments show that the new model not only gets better visual effects but also obtains higher signal to noise ratio than the recent method. 展开更多
关键词 total variation wavelet inpainting primal-dual method
下载PDF
Rapid Springback Compensation for Age Forming Based on Quasi Newton Method 被引量:3
5
作者 XIONG Wei GAN Zhong +1 位作者 XIONG Shipeng XIA Yushan 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2014年第3期551-557,共7页
Iterative methods based on finite element simulation are effective approaches to design mold shape to compensate springback in sheet metal forming. However, convergence rate of iterative methods is difficult to improv... Iterative methods based on finite element simulation are effective approaches to design mold shape to compensate springback in sheet metal forming. However, convergence rate of iterative methods is difficult to improve greatly. To increase the springback compensate speed of designing age forming mold, process of calculating springback for a certain mold with finite element method is analyzed. Springback compensation is abstracted as finding a solution for a set of nonlinear functions and a springback compensation algorithm is presented on the basis of quasi Newton method. The accuracy of algorithm is verified by developing an ABAQUS secondary development program with MATLAB. Three rectangular integrated panels of dimensions 710 mmx750 mm integrated panels with intersected ribs of 10 mm are selected to perform case studies. The algorithm is used to compute mold contours for the panels with cylinder, sphere and saddle contours respectively and it takes 57%, 22% and 33% iterations as compared to that of displacement adjustment (DA) method. At the end of iterations, maximum deviations on the three panels are 0.618 4 mm, 0.624 1 mm and 0.342 0 mm that are smaller than the deviations determined by DA method (0.740 8 mm, 0.740 8 mm and 0.713 7 mm respectively). In following experimental verification, mold contour for another integrated panel with 400 ram^380 mm size is designed by the algorithm. Then the panel is age formed in an autoclave and measured by a three dimensional digital measurement devise. Deviation between measuring results and the panel's design contour is less than 1 mm. Finally, the iterations with different mesh sizes (40 mm, 35 mm, 30 mm, 25 mm, 20 mm) in finite element models are compared and found no considerable difference. Another possible compensation method, Broyden-Fletcher-Shanmo method, is also presented based on the solving nonlinear fimctions idea. The Broyden-Fletcher-Shanmo method is employed to compute mold contour for the second panel. It only takes 50% iterations compared to that of DA. The proposed method can serve a faster mold contour compensation method for sheet metal forming. 展开更多
关键词 age forming quasi newton method springback compensation mold design displacement adjustment method
下载PDF
A class of polynomial primal-dual interior-point algorithms for semidefinite optimization 被引量:6
6
作者 王国强 白延琴 《Journal of Shanghai University(English Edition)》 CAS 2006年第3期198-207,共10页
In the present paper we present a class of polynomial primal-dual interior-point algorithms for semidefmite optimization based on a kernel function. This kernel function is not a so-called self-regular function due to... In the present paper we present a class of polynomial primal-dual interior-point algorithms for semidefmite optimization based on a kernel function. This kernel function is not a so-called self-regular function due to its growth term increasing linearly. Some new analysis tools were developed which can be used to deal with complexity "analysis of the algorithms which use analogous strategy in [5] to design the search directions for the Newton system. The complexity bounds for the algorithms with large- and small-update methodswere obtained, namely,O(qn^(p+q/q(P+1)log n/ε and O(q^2√n)log n/ε,respectlvely. 展开更多
关键词 semidefinite optimization (SDO) primal-dual interior-point methods large- and small-update methods polynomial complexity
下载PDF
A Fourth-order Covergence Newton-type Method 被引量:3
7
作者 WANG Xia ZHAO Ling-ling 《Chinese Quarterly Journal of Mathematics》 CSCD 北大核心 2008年第4期589-593,共5页
A fourth-order convergence method of solving roots for nonlinear equation, which is a variant of Newton's method given. Its convergence properties is proved. It is at least fourth-order convergence near simple roots ... A fourth-order convergence method of solving roots for nonlinear equation, which is a variant of Newton's method given. Its convergence properties is proved. It is at least fourth-order convergence near simple roots and one order convergence near multiple roots. In the end, numerical tests are given and compared with other known Newton and Newton-type methods. The results show that the proposed method has some more advantages than others. It enriches the methods to find the roots of non-linear equations and it is important in both theory and application. 展开更多
关键词 newton iteration method root-finding method fourth-order convergence numerical test
下载PDF
A Smoothing Newton Method for the Box Constrained Variational Inequality Problems 被引量:1
8
作者 XIE Ya-jun MA Chang-feng 《Chinese Quarterly Journal of Mathematics》 CSCD 2012年第1期152-158,共7页
The box constrained variational inequality problem can be reformulated as a nonsmooth equation by using median operator.In this paper,we present a smoothing Newton method for solving the box constrained variational in... The box constrained variational inequality problem can be reformulated as a nonsmooth equation by using median operator.In this paper,we present a smoothing Newton method for solving the box constrained variational inequality problem based on a new smoothing approximation function.The proposed algorithm is proved to be well defined and convergent globally under weaker conditions. 展开更多
关键词 median operator variational inequality problem smoothing newton method global convergence
下载PDF
On Newton-Like Methods for Solving Nonlinear Equations 被引量:1
9
作者 KOU Jisheng LIU Dingyou LI Yitian HE Julin 《Geo-Spatial Information Science》 2006年第1期76-78,共3页
In this paper, we present a family of general New to n-like methods with a parametric function for finding a zero of a univariate fu nction, permitting f′(x)=0 in some points. The case of multiple roots is n ot treat... In this paper, we present a family of general New to n-like methods with a parametric function for finding a zero of a univariate fu nction, permitting f′(x)=0 in some points. The case of multiple roots is n ot treated. The methods are proved to be quadratically convergent provided the w eak condition. Thus the methods remove the severe condition f′(x)≠0. Based on the general form of the Newton-like methods, a family of new iterative meth ods with a variable parameter are developed. 展开更多
关键词 newton method newton-like method nonlinear equations iteration method
下载PDF
3D magnetotelluric inversions with unstructured finite-element and limited-memory quasi-Newton methods 被引量:8
10
作者 Cao Xiao-Yue Yin Chang-Chun +3 位作者 Zhang Bo Huang Xin Liu Yun-He Cai Jing 《Applied Geophysics》 SCIE CSCD 2018年第3期556-565,共10页
Traditional 3D Magnetotelluric(MT) forward modeling and inversions are mostly based on structured meshes that have limited accuracy when modeling undulating surfaces and arbitrary structures. By contrast, unstructured... Traditional 3D Magnetotelluric(MT) forward modeling and inversions are mostly based on structured meshes that have limited accuracy when modeling undulating surfaces and arbitrary structures. By contrast, unstructured-grid-based methods can model complex underground structures with high accuracy and overcome the defects of traditional methods, such as the high computational cost for improving model accuracy and the difficulty of inverting with topography. In this paper, we used the limited-memory quasi-Newton(L-BFGS) method with an unstructured finite-element grid to perform 3D MT inversions. This method avoids explicitly calculating Hessian matrices, which greatly reduces the memory requirements. After the first iteration, the approximate inverse Hessian matrix well approximates the true one, and the Newton step(set to 1) can meet the sufficient descent condition. Only one calculation of the objective function and its gradient are needed for each iteration, which greatly improves its computational efficiency. This approach is well-suited for large-scale 3D MT inversions. We have tested our algorithm on data with and without topography, and the results matched the real models well. We can recommend performing inversions based on an unstructured finite-element method and the L-BFGS method for situations with topography and complex underground structures. 展开更多
关键词 Magnetotelluric(MT) 3D inversion UNSTRUCTURED fi nite-element method QUASI-newton method L-BFGS
下载PDF
A Discrete Newton's Method for Gain Based Predistorter 被引量:1
11
作者 Xiaochen LIN Minglu JIN Aifei LIU 《International Journal of Communications, Network and System Sciences》 2008年第1期16-21,共6页
Gain based predistorter (PD) is a highly effective and simple digital baseband predistorter which compensates for the nonlinear distortion of PAs. Lookup table (LUT) is the core of the gain based PD. This paper presen... Gain based predistorter (PD) is a highly effective and simple digital baseband predistorter which compensates for the nonlinear distortion of PAs. Lookup table (LUT) is the core of the gain based PD. This paper presents a discrete Newton’s method based adaptive technique to modify LUT. We simplify and convert the hardship of adaptive updating LUT to the roots finding problem for a system of two element real equations on athematics. And we deduce discrete Newton’s method based adaptive iterative formula used for updating LUT. The iterative formula of the proposed method is in real number field, but secant method previously published is in complex number field. So the proposed method reduces the number of real multiplications and is implemented with ease by hardware. Furthermore, computer simulation results verify gain based PD using discrete Newton’s method could rectify nonlinear distortion and improve system performance. Also, the simulation results reveal the proposed method reaches to the stable statement in fewer iteration times and less runtime than secant method. 展开更多
关键词 PREDISTORTION DISCRETE newton’s method Power Amplifiers (PAs) LOOKUP Table (LUT)
下载PDF
Research on BP Neural Network Algorithm Based on Quasi- Newton Method 被引量:3
12
作者 Lu Peixin 《International Journal of Technology Management》 2014年第7期71-74,共4页
With more and more researches about improving BP algorithm, there are more improvement methods. The paper researches two improvement algorithms based on quasi-Newton method, DFP algorithm and L-BFGS algorithm. After f... With more and more researches about improving BP algorithm, there are more improvement methods. The paper researches two improvement algorithms based on quasi-Newton method, DFP algorithm and L-BFGS algorithm. After fully analyzing the features of quasi- Newton methods, the paper improves BP neural network algorithm. And the adjustment is made for the problems in the improvement process. The paper makes empirical analysis and proves the effectiveness of BP neural network algorithm based on quasi-Newton method. The improved algorithms are compared with the traditional BP algorithm, which indicates that the imoroved BP algorithm is better. 展开更多
关键词 newton method BP neural network improved algorithm
下载PDF
Power System State Estimation Solution With Zero Injection Constraints Using Modified Newton Method and Fast Decoupled Method in Polar Coordinate 被引量:13
13
作者 GUO Ye ZHANG Boming WU Wenchuag SUN Hongbin 《中国电机工程学报》 EI CSCD 北大核心 2012年第22期I0015-I0015,11,共1页
如何保证零注入节点的注入功率在状态估计结果中严格为0是电力系统状态估计研究中的重要问题。在直角坐标下,由于零注入约束为线性约束,可使用修正牛顿法来有效地解决这一问题。因此,借鉴直角坐标下修正牛顿法的思路,提出了极坐标下的... 如何保证零注入节点的注入功率在状态估计结果中严格为0是电力系统状态估计研究中的重要问题。在直角坐标下,由于零注入约束为线性约束,可使用修正牛顿法来有效地解决这一问题。因此,借鉴直角坐标下修正牛顿法的思路,提出了极坐标下的修正牛顿法和修正快速解耦估计。这些方法的计算流程与传统的极坐标下的牛顿法和快速解耦估计非常相似,计算速度与大权重法相当,同时能够保证零注入约束严格满足。仿真结果验证了所得结论。 展开更多
关键词 状态估计模型 电力系统 解耦方法 注射 极坐标 牛顿法 基尔霍夫电流定律 电压变压器
下载PDF
FPGA-based Acceleration of Davidon-Fletcher-Powell Quasi-Newton Optimization Method 被引量:2
14
作者 Liu Qiang Sang Ruoyu Zhang Qijun 《Transactions of Tianjin University》 EI CAS 2016年第5期381-387,共7页
Quasi-Newton methods are the most widely used methods to find local maxima and minima of functions in various engineering practices. However, they involve a large amount of matrix and vector operations, which are comp... Quasi-Newton methods are the most widely used methods to find local maxima and minima of functions in various engineering practices. However, they involve a large amount of matrix and vector operations, which are computationally intensive and require a long processing time. Recently, with the increasing density and arithmetic cores, field programmable gate array(FPGA) has become an attractive alternative to the acceleration of scientific computation. This paper aims to accelerate Davidon-Fletcher-Powell quasi-Newton(DFP-QN) method by proposing a customized and pipelined hardware implementation on FPGAs. Experimental results demonstrate that compared with a software implementation, a speed-up of up to 17 times can be achieved by the proposed hardware implementation. 展开更多
关键词 QUASI-newton method hardware ACCELERATION field PROGRAMMABLE gate array
下载PDF
GLOBAL COVERGENCE OF THE NON-QUASI-NEWTON METHOD FOR UNCONSTRAINED OPTIMIZATION PROBLEMS 被引量:6
15
作者 Liu Hongwei Wang Mingjie +1 位作者 Li Jinshan Zhang Xiangsun 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2006年第3期276-288,共13页
In this paper, the non-quasi-Newton's family with inexact line search applied to unconstrained optimization problems is studied. A new update formula for non-quasi-Newton's family is proposed. It is proved that the ... In this paper, the non-quasi-Newton's family with inexact line search applied to unconstrained optimization problems is studied. A new update formula for non-quasi-Newton's family is proposed. It is proved that the constituted algorithm with either Wolfe-type or Armijotype line search converges globally and Q-superlinearly if the function to be minimized has Lipschitz continuous gradient. 展开更多
关键词 non-quasi-newton method inexact line search global convergence unconstrained optimization superlinear convergence.
下载PDF
CONVERGENCE OF INEXACT CONIC NEWTON METHODS
16
作者 胡蓉 盛松柏 《Numerical Mathematics A Journal of Chinese Universities(English Series)》 SCIE 1998年第2期159-168,共10页
A conic Newton method is attractive because it converges to a local minimizzer rapidly from any sufficiently good initial guess. However, it may be expensive to solve the conic Newton equation at each iterate. In this... A conic Newton method is attractive because it converges to a local minimizzer rapidly from any sufficiently good initial guess. However, it may be expensive to solve the conic Newton equation at each iterate. In this paper we consider an inexact conic Newton method, which solves the couic Newton equation oldy approximately and in sonm unspecified manner. Furthermore, we show that such method is locally convergent and characterizes the order of convergence in terms of the rate of convergence of the relative residuals. 展开更多
关键词 INEXACT CONIC newton method CONIC newton EQUATION relative RESIDUAL newton EQUATION FORCING sequence
下载PDF
Multi-train modeling and simulation integrated with traction power supply solver using simplified Newton–Raphson method 被引量:5
17
作者 Thanatchai Kulworawanichpong 《Journal of Modern Transportation》 2015年第4期241-251,共11页
Multi-train modeling and simulation plays a vital role in railway electrification during operation and planning phase. Study of peak power demand and energy consumed by each traction substation needs to be deter- mine... Multi-train modeling and simulation plays a vital role in railway electrification during operation and planning phase. Study of peak power demand and energy consumed by each traction substation needs to be deter- mined to verify that electrical energy flowing in its railway power feeding system is appropriate or not. Gauss-Seidel, conventional Newton-Raphson, and current injection methods are well-known and widely accepted as a tool for electrical power network solver in DC railway power supply study. In this paper, a simplified Newton-Raphson method has been proposed. The proposed method employs a set of current-balance equations at each electrical node instead of the conventional power-balance equation used in the conventional Newton-Raphson method. This concept can remarkably reduce execution time and computing complexity for multi-train simulation. To evaluate its use, Sukhumvit line of Bangkok transit system (BTS) of Thai- land with 21.6-km line length and 22 passenger stopping stations is set as a test system. The multi-train simulation integrated with the proposed power network solver is developed to simulate 1-h operation service of selected 5-min headway. From the obtained results, the proposed method is more efficient with approximately 18 % faster than the conventional Newton-Raphson method and just over 6 % faster than the current injection method. 展开更多
关键词 newton-Raphson method Gauss-Seidelmethod - Current-balance equation Current injectionmethod Multi-train simulation Power supply study
下载PDF
ON AMODIFIED NEWTON'S METHOD AND CONVERGENCE
18
作者 韩丹夫 《Numerical Mathematics A Journal of Chinese Universities(English Series)》 SCIE 1997年第1期107-112,共6页
In this paper we discuss the convergence of a modified Newton’s method presented by A. Ostrowski [1] and J.F. Traub [2], which has quadratic convergence order but reduces one evaluation of the derivative at every two... In this paper we discuss the convergence of a modified Newton’s method presented by A. Ostrowski [1] and J.F. Traub [2], which has quadratic convergence order but reduces one evaluation of the derivative at every two steps compared with Newton’s method. A convergence theorem is established by using a weak condition a≤3-2(2<sup>1/2</sup>) and a sharp error estimate is given about the iterative sequence. 展开更多
关键词 MODIFIED newton’s method CONVERGENCE majurant method ERROR estimate.
下载PDF
An Augmented Lagrangian based Semismooth Newton Method for a Class of Bilinear Programming Problems
19
作者 HE Su-xiang LIU Yan WANG Chuan-mei 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2019年第4期446-459,共14页
This paper proposes a semismooth Newton method for a class of bilinear programming problems(BLPs)based on the augmented Lagrangian,in which the BLPs are reformulated as a system of nonlinear equations with original va... This paper proposes a semismooth Newton method for a class of bilinear programming problems(BLPs)based on the augmented Lagrangian,in which the BLPs are reformulated as a system of nonlinear equations with original variables and Lagrange multipliers.Without strict complementarity,the convergence of the method is studied by means of theories of semismooth analysis under the linear independence constraint qualification and strong second order sufficient condition.At last,numerical results are reported to show the performance of the proposed method. 展开更多
关键词 SEMISMOOTH newton method constrained BILINEAR programming problems AUGMENTED LAGRANGIAN STRICT complementarity
下载PDF
A SPARSE SUBSPACE TRUNCATED NEWTON METHOD FOR LARGE-SCALE BOUND CONSTRAINED NONLINEAR OPTIMIZATION
20
作者 倪勤 《Numerical Mathematics A Journal of Chinese Universities(English Series)》 SCIE 1997年第1期27-37,共11页
In this paper we report a sparse truncated Newton algorithm for handling large-scale simple bound nonlinear constrained minimixation problem. The truncated Newton method is used to update the variables with indices ou... In this paper we report a sparse truncated Newton algorithm for handling large-scale simple bound nonlinear constrained minimixation problem. The truncated Newton method is used to update the variables with indices outside of the active set, while the projected gradient method is used to update the active variables. At each iterative level, the search direction consists of three parts, one of which is a subspace truncated Newton direction, the other two are subspace gradient and modified gradient directions. The subspace truncated Newton direction is obtained by solving a sparse system of linear equations. The global convergence and quadratic convergence rate of the algorithm are proved and some numerical tests are given. 展开更多
关键词 The TRUNCATED newton method LARGE-SCALE SPARSE problems BOUND constrained nonlinear optimization.
下载PDF
上一页 1 2 156 下一页 到第
使用帮助 返回顶部