期刊文献+
共找到2,507篇文章
< 1 2 126 >
每页显示 20 50 100
Application of Series Formula Method in Optimization Arrangement of Webs
1
作者 Qiaozhi Sang Siwen Li +1 位作者 Shuqi Wang Dianxuan Gong 《World Journal of Engineering and Technology》 2018年第3期651-660,共10页
The expressions of the internal forces of the webs under the vertical loads of the simply supported beam type trusses with vertical and horizontal webs and without vertical webs are studied through the mathematical fo... The expressions of the internal forces of the webs under the vertical loads of the simply supported beam type trusses with vertical and horizontal webs and without vertical webs are studied through the mathematical formula method. The variations of internal forces under different angles and spacings of the webs are simulated. The law of the optimal arrangement of the webs of the parallel-string simple-beam truss is obtained: under the condition that the rigidity of the rod is allowed, the form of no vertical web-type truss and reducing the span distance and inclination of the side span are advisable, which can save materials and reduce the weight as well. This method can be applied to the calculation of internal forces for arbitrary loads and truss forms. 展开更多
关键词 SERIES formula method BEAM TRUSS OPTIMUM Arrangement of WEBS
下载PDF
Recursion-transform method and potential formulae of the m×n cobweb and fan networks 被引量:11
2
作者 谭志中 《Chinese Physics B》 SCIE EI CAS CSCD 2017年第9期82-90,共9页
In this paper, we made a new breakthrough, which proposes a new recursion–transform(RT) method with potential parameters to evaluate the nodal potential in arbitrary resistor networks. For the first time, we found ... In this paper, we made a new breakthrough, which proposes a new recursion–transform(RT) method with potential parameters to evaluate the nodal potential in arbitrary resistor networks. For the first time, we found the exact potential formulae of arbitrary m × n cobweb and fan networks by the RT method, and the potential formulae of infinite and semi-infinite networks are derived. As applications, a series of interesting corollaries of potential formulae are given by using the general formula, the equivalent resistance formula is deduced by using the potential formula, and we find a new trigonometric identity by comparing two equivalence results with different forms. 展开更多
关键词 recursion-transform method network model potential formula exact solution
下载PDF
A GENERALIZED GAUSS-TYPE QUADRATURE FORMULA AND ITS APPLICATIONS TO PSEUDOSPECTRAL METHOD
3
作者 王立联 郭本瑜 王中庆 《Numerical Mathematics A Journal of Chinese Universities(English Series)》 SCIE 2002年第2期179-196,共18页
A generalized Gauss-type quadrature formula is introduced, which assists in selection of collocation points in pseudospectral method for differential equations with two-point derivative boundary conditions. Some resul... A generalized Gauss-type quadrature formula is introduced, which assists in selection of collocation points in pseudospectral method for differential equations with two-point derivative boundary conditions. Some results on the related Jacobi interpolation are established. A pseudospectral scheme is proposed for the Kuramoto-Sivashisky equation. A skew symmetric decomposition is used for dealing with the nonlinear convection term. The stability and convergence of the proposed scheme are proved. The error estimates are obtained. Numerical results show the efficiency of this approach. 展开更多
关键词 GENERALIZED Gauss-type QUADRATURE formula PSEUDOSPECTRAL method K-S equa-tion.
下载PDF
The Convergences Comparison between the Halley’s Method and Its Extended One Based on Formulas Derivation and Numerical Calculations
4
作者 Shunji Horiguchi 《Applied Mathematics》 2016年第18期2394-2410,共17页
The purpose of this paper is that we give an extension of Halley’s method (Section 2), and the formulas to compare the convergences of the Halley’s method and extended one (Section 3). For extension of Halley’s met... The purpose of this paper is that we give an extension of Halley’s method (Section 2), and the formulas to compare the convergences of the Halley’s method and extended one (Section 3). For extension of Halley’s method we give definition of function by variable transformation in Section 1. In Section 4 we do the numerical calculations of Halley’s method and extended one for elementary functions, compare these convergences, and confirm the theory. Under certain conditions we can confirm that the extended Halley’s method has better convergence or better approximation than Halley’s method. 展开更多
关键词 Recurrence formula Newton’s method Halley’s method Extension of Halley’s method Third-Order Convergence
下载PDF
A Nonstationary Halley’s Iteration Method by Using Divided Differences Formula
5
作者 Nasr Al Din Ide 《Applied Mathematics》 2012年第2期169-171,共3页
This paper presents a new nonstationary iterative method for solving non linear algebraic equations that does not require the use of any derivative. The study uses only the Newton’s divided differences of first and s... This paper presents a new nonstationary iterative method for solving non linear algebraic equations that does not require the use of any derivative. The study uses only the Newton’s divided differences of first and second orders instead of the derivatives of (1). 展开更多
关键词 NONSTATIONARY ITERATIVE method Hally’s formula Divided DIFFERENCES
下载PDF
On Relations between the General Recurrence Formula of the Extension of Murase-Newton’s Method (the Extension of Tsuchikura*-Horiguchi’s Method) and Horner’s Method
6
作者 Shunji Horiguchi 《Applied Mathematics》 2014年第4期777-783,共7页
In 1673, Yoshimasu Murase made a cubic equation to obtain the thickness of a hearth. He introduced two kinds of recurrence formulas of square and the deformation (Ref.[1]). We find that the three formulas lead to the ... In 1673, Yoshimasu Murase made a cubic equation to obtain the thickness of a hearth. He introduced two kinds of recurrence formulas of square and the deformation (Ref.[1]). We find that the three formulas lead to the extension of Newton-Raphson’s method and Horner’s method at the same time. This shows originality of Japanese native mathematics (Wasan) in the Edo era (1600- 1867). Suzuki (Ref.[2]) estimates Murase to be a rare mathematician in not only the history of Wasan but also the history of mathematics in the world. Section 1 introduces Murase’s three solutions of the cubic equation of the hearth. Section 2 explains the Horner’s method. We give the generalization of three formulas and the relation between these formulas and Horner’s method. Section 3 gives definitions of Murase-Newton’s method (Tsuchikura-Horiguchi’s method), general recurrence formula of Murase-Newton’s method (Tsuchikura-Horiguchi’s method), and general recurrence formula of the extension of Murase-Newton’s method (the extension of Tsuchikura-Horiguchi’s method) concerning n-degree polynomial equation. Section 4 is contents of the title of this paper. 展开更多
关键词 RECURRENCE formula Newton-Raphson’s method (Newton’s method) EXTENSIONS of Murase-Newton’s method Horner’s method
下载PDF
The Formulas to Compare the Convergences of Newton’s Method and the Extended Newton’s Method (Tsuchikura-Horiguchi Method) and the Numerical Calculations
7
作者 Shunji Horiguchi 《Applied Mathematics》 2016年第1期40-60,共21页
This paper gives the extension of Newton’s method, and a variety of formulas to compare the convergences for the extension of Newton’s method (Section 4). Section 5 gives the numerical calculations. Section 1 introd... This paper gives the extension of Newton’s method, and a variety of formulas to compare the convergences for the extension of Newton’s method (Section 4). Section 5 gives the numerical calculations. Section 1 introduces the three formulas obtained from the cubic equation of a hearth by Murase (Ref. [1]). We find that Murase’s three formulas lead to a Horner’s method (Ref. [2]) and extension of a Newton’s method (2009) at the same time. This shows originality of Wasan (mathematics developed in Japan) in the Edo era (1603-1868). Suzuki (Ref. [3]) estimates Murase to be a rare mathematician in not only the history of Wasan but also the history of mathematics in the world. Section 2 gives the relations between Newton’s method, Horner’s method and Murase’s three formulas. Section 3 gives a new function defined such as . 展开更多
关键词 Recurrence formula Newton-Raphson’s method (Newton’s method) Extension of Newton’s method
下载PDF
Precise integration methods based on the Chebyshev polynomial of the first kind 被引量:2
8
作者 Wang Mengfu F. T. K. Au 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2008年第2期207-216,共10页
This paper introduces two new types of precise integration methods based on Chebyshev polynomial of the first kind for dynamic response analysis of structures, namely the integral formula method (IFM) and the homoge... This paper introduces two new types of precise integration methods based on Chebyshev polynomial of the first kind for dynamic response analysis of structures, namely the integral formula method (IFM) and the homogenized initial system method (HISM). In both methods, nonlinear variable loadings within time intervals are simulated using Chebyshev polynomials of the first kind before a direct integration is performed. Developed on the basis of the integral formula, the recurrence relationship of the integral computation suggested in this paper is combined with the Crout decomposed method to solve linear algebraic equations. In this way, the IFM based on Chebyshev polynomial of the first kind is constructed. Transforming the non-homogenous initial system to the homogeneous dynamic system, and developing a special scheme without dimensional expansion, the HISM based on Chebyshev polynomial of the first kind is able to avoid the matrix inversion operation. The accuracy of the time integration schemes is examined and compared with other commonly used schemes, and it is shown that a greater accuracy as well as less time consuming can be achieved. Two numerical examples are presented to demonstrate the applicability of these new methods. 展开更多
关键词 structural dynamics Chebyshev polynomial of the first kind the Crout decomposed method integral formula method homogenized initial system method
下载PDF
An explicit method for numerical simulation of wave equations 被引量:3
9
作者 Liu Heng Liao Zhenpeng 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2009年第1期17-28,共12页
In this paper, a method to develop a hierarchy of explicit recursion formulas for numerical simulation in an irregular grid for scalar wave equations is presented and its accuracy is illustrated via 2-D and 1-D models... In this paper, a method to develop a hierarchy of explicit recursion formulas for numerical simulation in an irregular grid for scalar wave equations is presented and its accuracy is illustrated via 2-D and 1-D models. Approaches to develop the stable formulas which are of 2M-order accuracy in both time and space with Mbeing a positive integer for regular grids are discussed and illustrated by constructing the second order (M= 1) and the fourth order (M = 2) recursion formulas. 展开更多
关键词 wave equation numerical simulation explicit recursion formula finite element method
下载PDF
A LIMITED MEMORY QUASI-NEWTON METHOD FOR LARGE SCALE PROBLEM 被引量:3
10
作者 邓卫兵 《Numerical Mathematics A Journal of Chinese Universities(English Series)》 SCIE 1996年第1期71-79,共9页
We study how to use the SR1 update to realize minimization methods for problems where the storage is critical. We give an update formula which generates matrices using information from the last m iterations. The numer... We study how to use the SR1 update to realize minimization methods for problems where the storage is critical. We give an update formula which generates matrices using information from the last m iterations. The numerical tests show that the method is efficent. 展开更多
关键词 LARGE SCALE PROBLEM LIMITED MEMORY methods SR1 formula.
下载PDF
ON RITZ METHOD OF ANINTEGRO-DIFFERENTIAL EQUAITON 被引量:1
11
作者 丁夏畦 罗佩珠 《Acta Mathematica Scientia》 SCIE CSCD 2009年第3期687-696,共10页
This paper deals with the Ritz method of an integro-differential equation related with Riemann zeta-function.
关键词 ZETA-FUNCTION Ritz method explicit formula
下载PDF
An explicit method for numerical simulation of wave equations: 3D wave motion 被引量:1
12
作者 Liu Heng Liao Zhenpeng 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2011年第1期13-20,共8页
In this paper, an explicit method is generalized from 1D and 2D models to a 3D model for numerical simulation of wave motion, and the corresponding recursion formulas are developed for 3D irregular grids. For uniform ... In this paper, an explicit method is generalized from 1D and 2D models to a 3D model for numerical simulation of wave motion, and the corresponding recursion formulas are developed for 3D irregular grids. For uniform cubic grids, the approach used to establish stable formulas with 2M-order accuracy is discussed in detail, with M being a positive integer, and is illustrated by establishing second order (M=1) recursion formulas. The theoretical results presented in this paper are demonstrated through numerical testing. 展开更多
关键词 3D wave equation numerical simulation explicit recursion formula finite element method
下载PDF
退耕还林地生态环境损害评估案例分析及应用 被引量:1
13
作者 周海兰 姜苹红 +1 位作者 唐彬 赵文涛 《环境科技》 2024年第1期40-46,共7页
近年来,随着我国经济的高速发展,林地生态环境损害事件日益增加。不同类型的生态系统或同一生态系统在不同区域所提供的生态服务功能侧重均不同,鉴定评估林地生态系统的环境损害价值时应选用不同的测算方法。通过阐述理论公式法和实际... 近年来,随着我国经济的高速发展,林地生态环境损害事件日益增加。不同类型的生态系统或同一生态系统在不同区域所提供的生态服务功能侧重均不同,鉴定评估林地生态系统的环境损害价值时应选用不同的测算方法。通过阐述理论公式法和实际监测法的原理和适用范围及其在生态环境损害评估中的应用,并对量化过程中参数的选取原则与方法进行说明。结合案例分析非法占用退耕还林地导致的生态环境损害范围和程度,计算出2012年~2019年的生态环境损害价值量为205万元。研究退耕还林地生态环境损害典型案例,并将其推广应用于小规模普通林地,对林地生态环境损害案件的鉴定评估环节具有重要引领作用。 展开更多
关键词 生态环境损害 退耕还林地 理论公式法 生态服务功能价值 鉴定评估
下载PDF
地下水型饮用水水源补给区划分——以辽宁省沈阳市北部某地区饮用水水源为例 被引量:1
14
作者 王英刚 唐小涵 +3 位作者 岳景鹏 金赵明 王子兴 赵杨帆 《沈阳大学学报(自然科学版)》 CAS 2024年第3期198-204,共7页
选择辽宁省沈阳市北部某地区集中式地下水型饮用水水源作为研究区,收集其地形地貌、水源所属地下水含水系统的地质和水文地质概况等相关信息进行分析。选择公式法,根据含水层岩性,采取经验值参数,以水源开采井保护区外为基准,以15 a(547... 选择辽宁省沈阳市北部某地区集中式地下水型饮用水水源作为研究区,收集其地形地貌、水源所属地下水含水系统的地质和水文地质概况等相关信息进行分析。选择公式法,根据含水层岩性,采取经验值参数,以水源开采井保护区外为基准,以15 a(5475 d)为地下水质点迁移时间,计算得出补给区面积为40.18 km^(2)。鉴于补给区边界部分横跨村庄,在补给区定界过程中,将横跨村庄纳入补给区范围内,切实加强补给区安全防护。并从补给区环境管理方面提出对策和建议。 展开更多
关键词 地下水型饮用水水源 公式法 补给区划分 地下水流向 水文地质
下载PDF
The Application and Comparison of ThreeDifferent Methods in Option Pricing
15
作者 JIN Ying JIN Zhe-zhi 《信息工程期刊(中英文版)》 2016年第5期16-20,共5页
关键词 信息系统 分析方法 信息技术 价格分析
下载PDF
Cake Filtration Equation Using tan<sup>n</sup><i>θ</i>Reduction Method
16
作者 Obiajulu E. Udegbunam Joel O. Ademiluyi 《Journal of Water Resource and Protection》 2017年第7期851-872,共22页
This study was completed by an extensive mathematical analysis. New equation to sludge filtration processes has been proposed for use in routine laboratory. The equation has been suggested to replace Ademiluyi’s cake... This study was completed by an extensive mathematical analysis. New equation to sludge filtration processes has been proposed for use in routine laboratory. The equation has been suggested to replace Ademiluyi’s cake filtration equation in view of the limitations of the latter. The new equation can be used for sludges whose compressibility factor is more than one but Ademiluyi’s cake filtration equation can only be used for sludges whose compressibility coefficient is less than one. The new sludge filtration equation was derived using tannθ reduction method. The generalized equation thus obtained resembles Ademiluyi’s equation in the mode of parameter combination except the presence of summation notation in the new equation. 展开更多
关键词 tannθ method Reduction formula Sludge Filtration EQUATION Piezometric POSITIONS and COMPRESSIBILITY Factor
下载PDF
大庆油田长垣地区萨零组横波速度预测方法研究
17
作者 孙丽静 李存荣 +2 位作者 王贤君 李丽丽 李永环 《石油地质与工程》 CAS 2024年第4期63-68,共6页
萨零组是大庆油田萨尔图油层组顶部发育的一个沉积单元,含油面积广,油气资源丰富。萨零组储层致密、物性差、一直未动用,为了对大庆油田长垣地区萨零组进行高质量勘探开发,急需开展萨零组储层横波速度预测方法的研究。根据萨零组在平面... 萨零组是大庆油田萨尔图油层组顶部发育的一个沉积单元,含油面积广,油气资源丰富。萨零组储层致密、物性差、一直未动用,为了对大庆油田长垣地区萨零组进行高质量勘探开发,急需开展萨零组储层横波速度预测方法的研究。根据萨零组在平面上的分布特征,将长垣地区由南到北分5个区块,以67口井Xmac测井曲线和全波声波测井资料为基础,采用最小二乘法,分别进行线性关系和二次多项式关系拟合,得到长垣地区不同区块的纵横波速度经验公式。线性关系拟合的相关指数比二次多项式关系拟合的相关指数小,二次多项式关系预测值更接近实测值,应用不同区块的经验公式可以预测出横波速度,弥补了萨零组横波速度资料少的问题,对于提高垂向应力解释精度、判断压后裂缝形态等方面具有参考价值。 展开更多
关键词 长垣地区 萨零组 经验公式法 横波速度 纵波速度
下载PDF
On Solving a System of Volterra Integral Equations with Relaxed Monte Carlo Method
18
作者 Zhimin Hong Xiangzhong Fang +1 位作者 Zaizai Yan Hui Hao 《Journal of Applied Mathematics and Physics》 2016年第7期1315-1320,共7页
A random simulation method was used for treatment of systems of Volterra integral equations of the second kind. Firstly, a linear algebra system was obtained by discretization using quadrature formula. Secondly, this ... A random simulation method was used for treatment of systems of Volterra integral equations of the second kind. Firstly, a linear algebra system was obtained by discretization using quadrature formula. Secondly, this algebra system was solved by using relaxed Monte Carlo method with importance sampling and numerical approximation solutions of the integral equations system were achieved. It is theoretically proved that the validity of relaxed Monte Carlo method is based on importance sampling to solve the integral equations system. Finally, some numerical examples from literatures are given to show the efficiency of the method. 展开更多
关键词 Systems of Volterra Integral Equations Quadrature formula Relaxed Monte Carlo method Importance Sampling
下载PDF
国医大师张大宁教授以膏方辨治阴虚型慢性肾脏病经验总结
19
作者 何学志 张勉之 +5 位作者 韩阳 范军 孙岚云 王莹 刘亚燊 张大宁 《天津中医药》 CAS 2024年第3期277-280,共4页
慢性肾脏病逐渐成为临床最常见的慢性疾病之一,严重影响了人民群众的身体健康,国医大师张大宁教授作为中医肾脏病的奠基人,在长期的临床实践中,最早提出了“肾虚血瘀论”并首创“补肾活血法”,同时将补肾活血法融入膏方之中来治疗阴虚... 慢性肾脏病逐渐成为临床最常见的慢性疾病之一,严重影响了人民群众的身体健康,国医大师张大宁教授作为中医肾脏病的奠基人,在长期的临床实践中,最早提出了“肾虚血瘀论”并首创“补肾活血法”,同时将补肾活血法融入膏方之中来治疗阴虚型慢性肾脏病。文章总结了张大宁教授利用膏方治疗慢性肾脏病的经验,供读者参考。 展开更多
关键词 慢性肾脏病 补肾活血法 膏方 张大宁
下载PDF
Multistep Quadrature Based Methods for Nonlinear System of Equations with Singular Jacobian
20
作者 Oghovese Ogbereyivwe Kingsley Obiajulu Muka 《Journal of Applied Mathematics and Physics》 2019年第3期702-725,共24页
Methods for the approximation of solution of nonlinear system of equations often fail when the Jacobians of the systems are singular at iteration points. In this paper, multi-step families of quadrature based iterativ... Methods for the approximation of solution of nonlinear system of equations often fail when the Jacobians of the systems are singular at iteration points. In this paper, multi-step families of quadrature based iterative methods for approximating the solution of nonlinear system of equations with singular Jacobian are developed using decomposition technique. The methods proposed in this study are of convergence order , and require only the evaluation of first-order Frechet derivative per iteration. The approximate solutions generated by the proposed iterative methods in this paper compared with some existing contemporary methods in literature, show that methods developed herein are efficient and adequate in approximating the solution of nonlinear system of equations whose Jacobians are singular and non-singular at iteration points. 展开更多
关键词 Nonlinear System of Equations QUADRATURE formula SINGULAR JACOBIAN Mul-tistep Iterative methods
下载PDF
上一页 1 2 126 下一页 到第
使用帮助 返回顶部