期刊文献+
共找到305篇文章
< 1 2 16 >
每页显示 20 50 100
A Basic Method of Constructing Production Functions
1
作者 Guo Yaohuang Wang Yaping Zhang Wel(School of Economics and Management,Soultwest Jiaotong University), Chengdu 610031,China 《Journal of Modern Transportation》 1995年第2期127-132,共6页
In this paper,a new basic method of constructing smooth production functions isgiven,and many ordinary production functions are drawn. It is obvious thatsome more production functions can be obtained from the method.
关键词 production function continuously differentiable function homogeneousfunction
下载PDF
A Numerical Method for Solving Ill-Conditioned Equation Systems Arising from Radial Basis Functions
2
作者 Edward J. Kansa 《American Journal of Computational Mathematics》 2023年第2期356-370,共15页
Continuously differentiable radial basis functions (C<sup>∞</sup>-RBFs), while being theoretically exponentially convergent are considered impractical computationally because the coefficient matrices are ... Continuously differentiable radial basis functions (C<sup>∞</sup>-RBFs), while being theoretically exponentially convergent are considered impractical computationally because the coefficient matrices are full and can become very ill- conditioned. Similarly, the Hilbert and Vandermonde have full matrices and become ill-conditioned. The difference between a coefficient matrix generated by C<sup>∞</sup>-RBFs for partial differential or integral equations and Hilbert and Vandermonde systems is that C<sup>∞</sup>-RBFs are very sensitive to small changes in the adjustable parameters. These parameters affect the condition number and solution accuracy. The error terrain has many local and global maxima and minima. To find stable and accurate numerical solutions for full linear equation systems, this study proposes a hybrid combination of block Gaussian elimination (BGE) combined with arbitrary precision arithmetic (APA) to minimize the accumulation of rounding errors. In the future, this algorithm can execute faster using preconditioners and implemented on massively parallel computers. 展开更多
关键词 continuously differentiable Radial Basis functions Global Maxima and Minima Solutions of Ill-Conditioned Linear Equations Block Gaussian Elimination Arbitrary Precision Arithmetic
下载PDF
Sub-Differential Characterizations of Non-Smooth Lower Semi-Continuous Pseudo-Convex Functions on Real Banach Spaces
3
作者 Akachukwu Offia Ugochukwu Osisiogu +4 位作者 Theresa Efor Friday Oyakhire Monday Ekhator Friday Nkume Sunday Aloke 《Open Journal of Optimization》 2023年第3期99-108,共10页
In this paper, we characterize lower semi-continuous pseudo-convex functions f : X → R ∪ {+ ∞} on convex subset of real Banach spaces K  ⊂ X with respect to the pseudo-monotonicity of its Clarke-Rockafellar Su... In this paper, we characterize lower semi-continuous pseudo-convex functions f : X → R ∪ {+ ∞} on convex subset of real Banach spaces K  ⊂ X with respect to the pseudo-monotonicity of its Clarke-Rockafellar Sub-differential. We extend the results on the characterizations of non-smooth convex functions f : X → R ∪ {+ ∞} on convex subset of real Banach spaces K  ⊂ X with respect to the monotonicity of its sub-differentials to the lower semi-continuous pseudo-convex functions on real Banach spaces. 展开更多
关键词 Real Banach Spaces Pseudo-Convex functions Pseudo-Monotone Maps Sub-Differentials Lower Semi-Continuous functions and Approximate Mean Value Inequality
下载PDF
THE CONTINUAL DIFFERENTIABLE PEAK-UNIMODAL SOLUTIONS OF FEIGENBAUM’S FUNCTIONAL EQUATIONS
4
作者 程宝龙 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 1989年第5期419-426,共8页
For the famous Feigenbaum's equations, in this paper, we established its constructive theorem of the peak-unimodal, then we found out other paths to explore the peak-unimodal solutions. For example, we proceed on ... For the famous Feigenbaum's equations, in this paper, we established its constructive theorem of the peak-unimodal, then we found out other paths to explore the peak-unimodal solutions. For example, we proceed on the direction to try the non-symmetrical continuous peak-unimodal solutions and C1 solutions. 展开更多
关键词 THE CONTINUAL differentiable PEAK-UNIMODAL SOLUTIONS OF FEIGENBAUM S functionAL EQUATIONS
下载PDF
THE BASIC THEORY OF SOLUTIONS OF FUNCTIONAL DIFFERENTIAL EQUATIONS WITH BOUNDED DELAY IN THE SPACE OF INTEGRABLE FUNCTIONS
5
作者 刘永清 李远清 《华南理工大学学报(自然科学版)》 EI CAS CSCD 北大核心 1997年第7期67-73,共7页
在可积函数空间中讨论有界滞量泛函微分方程,建立其解的基本理论,包括解的存在性,唯一性及延展性。
关键词 有界滞量的泛函微分方程 存在性 唯一性 延展性 可积函数空间
下载PDF
EXISTENCE OF POSITIVE PERIODIC SOLUTIONS FOR NEUTRAL FUNCTIONAL DIFFERENTIAL EQUATIONS WITH DEVIATING ARGUMENTS 被引量:23
6
作者 LuShiping GeWeigao 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2002年第4期382-390,共9页
By means of an abstract continuation theorem, the existence criteria are established for the positive periodic solutions of a neutral functional differential equation d N d t=N(t)[a(t)-β(t)N(t)-b(t)N(t-σ(t))-c(... By means of an abstract continuation theorem, the existence criteria are established for the positive periodic solutions of a neutral functional differential equation d N d t=N(t)[a(t)-β(t)N(t)-b(t)N(t-σ(t))-c(t)N′(t-τ(t))]. 展开更多
关键词 positive periodic solution abstract continuation theorem neutral functional differential equation.
下载PDF
ON A CLASS OF ANALYTIC FUNCTIONS RELATED TO CONIC DOMAINS AND ASSOCIATED WITH CARLSON-SHAFFER OPERATOR 被引量:4
7
作者 S.Hussain J.Sokól 《Acta Mathematica Scientia》 SCIE CSCD 2012年第4期1399-1407,共9页
Making use of the Carlson-Shaffer convolution operator, we introduce and study a new class of analytic functions related to conic domains. The main object of this paper is to investigate inclusion relations, coefficie... Making use of the Carlson-Shaffer convolution operator, we introduce and study a new class of analytic functions related to conic domains. The main object of this paper is to investigate inclusion relations, coefficient bound for this class. We also show that this class is closed under convolution with a convex function. Some applications are also discussed. 展开更多
关键词 Hadamard product (or convolution) differential subordination Carlson-Shaffer operator k-starlike functions k-uniformly convex function
下载PDF
HOMOCLINIC SOLUTIONS FOR A CLASS OF SECOND ORDER NEUTRAL FUNCTIONAL DIFFERENTIAL SYSTEMS 被引量:2
8
作者 鲁世平 郑亮 陈丽娟 《Acta Mathematica Scientia》 SCIE CSCD 2013年第5期1361-1374,共14页
By means of an extension of Mawhin's continuation theorem and some analysis methods, the existence of a set with 2kT-periodic solutions for a class of second order neutral functional differential systems is studied, ... By means of an extension of Mawhin's continuation theorem and some analysis methods, the existence of a set with 2kT-periodic solutions for a class of second order neutral functional differential systems is studied, and then the homoclinic solutions are obtained as the limit points of a certain subsequence of the above set. 展开更多
关键词 homoclinic solution periodic solution neutral functional differential system Mawhin's continuation theorem
下载PDF
THIRD-ORDER DIFFERENTIAL SUBORDINATION RESULTS FOR ANALYTIC FUNCTIONS INVOLVING THE GENERALIZED BESSEL FUNCTIONS 被引量:4
9
作者 汤获 Erhan DENIZ 《Acta Mathematica Scientia》 SCIE CSCD 2014年第6期1707-1719,共13页
In the present paper, we derive some third-order differential subordination results for analytic functions in the open unit disk, using the operator Bcκf by means of normalized form of the generalized Bessel function... In the present paper, we derive some third-order differential subordination results for analytic functions in the open unit disk, using the operator Bcκf by means of normalized form of the generalized Bessel functions of the first kind, which is defined as z(Bκ+1^c f(z))′= κBκ^c f(z)-(κ- 1)Bκ+1^c f(z),where b, c, p ∈ C and κ = p +(b + 1)/2 ∈ C / Z0^-(Z0^-= {0,-1,-2, … }). The results are obtained by considering suitable classes of admissible functions. Various known or new special cases of our main results are also pointed out. 展开更多
关键词 differential subordination univalent functions Hadamard product admissible functions generalized Bessel functions
下载PDF
PERIODIC SOLUTIONS OF THIRD-ORDER FUNCTIONAL DIFFERENTIAL EQUATIONS WITH VARIABLE COEFFICIENTS 被引量:2
10
作者 Zhang Zhengqiu Wang ZhichengDept.ofAppl.Math.,HunanUniv.,Changsha410082,China 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2002年第2期145-154,共10页
The sufficient condition for the existence of2 π- periodic solutions of the following third- order functional differential equations with variable coefficients a(t) x (t) +bx″2 k- 1(t) +cx′2 k- 1(t) + 2 k- 1 i=1... The sufficient condition for the existence of2 π- periodic solutions of the following third- order functional differential equations with variable coefficients a(t) x (t) +bx″2 k- 1(t) +cx′2 k- 1(t) + 2 k- 1 i=1 cixi(t) +g(x(t-τ) ) =p(t) =p(t+2π) is obtained.The approach is based on the abstract continuation theorem from Mawhin and the a- priori estimate of periodic solutions 展开更多
关键词 periodic solution abstract continuation theorem a- priori estimate coincidence degree functional differential equation
下载PDF
CONSTRUCTION OF SOME KIESSWETTER-LIKE FUNCTIONS-THE CONTINUOUS BUT NON-DIFFERENT-IABLE FUNCTION DEFINED BY QUINARY DECIMAL 被引量:1
11
作者 TieYong YangGuangjun 《Analysis in Theory and Applications》 2004年第1期58-68,共11页
In this paper, we construct some continuous but non-differentiable functions defined by quinary dec-imal, that are Kiesswetter-like functions. We discuss their properties, then investigate the Hausdorff dimensions of ... In this paper, we construct some continuous but non-differentiable functions defined by quinary dec-imal, that are Kiesswetter-like functions. We discuss their properties, then investigate the Hausdorff dimensions of graphs of these functions and give a detailed proof. 展开更多
关键词 Kiesswetter-like functions continuous but non-differentiable quinary decimal iterated function system inequality Hausdorff dimension
下载PDF
Matrix description of differential relations of moment functions in structural reliability sensitivity analysis
12
作者 Tianxiao ZHANG 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2017年第1期57-72,共16页
In a structural system reliability analysis that lacks probabilistic information, calculating the numerical characteristics of the state functions, especially the first four moments of the state functions, is necessar... In a structural system reliability analysis that lacks probabilistic information, calculating the numerical characteristics of the state functions, especially the first four moments of the state functions, is necessary. Based on that, the structural system reliability is analyzed with a fourth-order moment method. The reliability sensitivity is required to conduct the differential operation of the numerical characteristic functions. A reliability sensitivity analysis formula is then derived in combination with the relation of the differential operation. Based on the matrix theory and Kronecker algebra, this paper systematically derives a matrix expression of the first four moments of the state functions, and establishes the matrix relation between the first four moments of the state functions and those of the basic random variables. On this basis, a differential operation formula of the first four moments of the state functions is further derived against the first four moments of the basic random variables. The vector relation between the state functions and the multidimensional basic random variables is described by means of the matrix operation to extend the operation method. Finally, a concise and intuitive formula is obtained to explore the inherent essential relation between the numerical characteristics of the state functions and those of the basic random variables, leading to a universal equation for the two kinds of numerical characteristics. 展开更多
关键词 structural system reliability analysis state function numerical characteristic matrix description Kronecker product functional differential reliability sensitivity
下载PDF
ON THE CONTINUITY AND DIFFERENTIABILITY OF AKIND OF FRACTAL INTERPOLATION FUNCTION
13
作者 李红达 叶正麟 高行山 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2002年第4期471-478,共8页
The sufficient conditions of Holder continuity of two kinds of fractal interpolation functions defined by IFS (Iterated Function System) were obtained. The sufficient and necessary condition for its differentiability ... The sufficient conditions of Holder continuity of two kinds of fractal interpolation functions defined by IFS (Iterated Function System) were obtained. The sufficient and necessary condition for its differentiability was proved. Its derivative was a fractal interpolation function generated by the associated IFS, if it is differentiable. 展开更多
关键词 FRACTAL interpolation function Holder continuity DIFFERENTIABILITY
下载PDF
On the Non-Trivial Zeros of Dirichlet Functions
14
作者 Dorin Ghisa 《Advances in Pure Mathematics》 2021年第3期187-204,共18页
The purpose of this research is to extend to the functions obtained by meromorphic continuation of general Dirichlet series some properties of the functions in the Selberg class, which are all generated by ordinary Di... The purpose of this research is to extend to the functions obtained by meromorphic continuation of general Dirichlet series some properties of the functions in the Selberg class, which are all generated by ordinary Dirichlet series. We wanted to put to work the powerful tool of the geometry of conformal mappings of these functions, which we built in previous research, in order to study the location of their non-trivial zeros. A new approach of the concept of multiplier in Riemann type of functional equation was necessary and we have shown that with this approach the non-trivial zeros of the Dirichlet function satisfying a Reimann type of functional equation are either on the critical line, or they are two by two symmetric with respect to the critical line. The Euler product general Dirichlet series are defined, a wide class of such series is presented, and finally by using geometric and analytic arguments it is proved that for Euler product functions the symmetric zeros with respect to the critical line must coincide. 展开更多
关键词 General Dirichlet Series Riemann Type of functional Equation Euler Products Fundamental Domains Analytic Continuation
下载PDF
On Horn Matrix Function <i>H<sub>2</sub>(A,A′,B,B′;C;z,w)</i>of Two Complex Variables under Differential Operator
15
作者 Mohamed Saleh Metwally Mahmoud Tawfik Mohamed Ayman Shehata 《Advances in Linear Algebra & Matrix Theory》 2018年第2期96-110,共15页
The aim of this paper deals with the study of the Horn matrix function of two complex variables. The convergent properties, an integral representation of H2(A,A′,B,B′;C;z,w) is obtained and recurrence matrix relatio... The aim of this paper deals with the study of the Horn matrix function of two complex variables. The convergent properties, an integral representation of H2(A,A′,B,B′;C;z,w) is obtained and recurrence matrix relations are given. Some result when operating on Horn matrix function with the differential operator D and a solution of certain partial differential equations are established. The Hadamard product of two Horn’s matrix functions is studied, certain results as, the domain of regularity, contiguous functional relations and operating with the differential operator D and D2 are established. 展开更多
关键词 HYPERGEOMETRIC MATRIX function HORN MATRIX function Integral Form Recurrence MATRIX Relation MATRIX DIFFERENTIAL Equation DIFFERENTIAL Operator Hadamard Product
下载PDF
差分跳频系统中基于迭代分解的G函数构造方法
16
作者 宁晓燕 金鹏 +1 位作者 王震铎 孙志国 《哈尔滨工程大学学报》 EI CAS CSCD 北大核心 2023年第5期876-883,共8页
差分跳频是跳频技术中提高数据传输速率的一种有效方式,频率转移函数是差分跳频研究的重点,本文针对现有的频率转移函数所生成的跳频序列性质上的不足,提出了一种时变的频率转移算法,通过m序列,对频率对进行迭代分解,进而控制频率之间... 差分跳频是跳频技术中提高数据传输速率的一种有效方式,频率转移函数是差分跳频研究的重点,本文针对现有的频率转移函数所生成的跳频序列性质上的不足,提出了一种时变的频率转移算法,通过m序列,对频率对进行迭代分解,进而控制频率之间的对应关系,同时根据发端算法构造了解映射算法。对算法进行了理论分析和仿真验证,仿真验证表明:相比于基于m序列、RS码和混沌序列加扰的G函数算法,新的转移算法是时变的,产生的跳频序列的随机性、均匀性和安全性得到了改善,二维连续性符合卡方检验的理论值,在通信性能上也有了部分提升。 展开更多
关键词 差分跳频 频率转移函数 时变性 二维连续性
下载PDF
正则化方法对连续协变量项目功能差异的检测及其应用
17
作者 甘凯宇 刘红云 《中国考试》 北大核心 2023年第9期44-51,共8页
提出检测连续协变量条件下项目功能差异的正则化方法,并将其与Logistic回归方法进行比较。模拟数据分析结果表明:1)在所有条件下,正则化方法的一类错误率比Logistic回归方法低。在DIF项目比例为20%时,正则化方法的检测效果优于Logistic... 提出检测连续协变量条件下项目功能差异的正则化方法,并将其与Logistic回归方法进行比较。模拟数据分析结果表明:1)在所有条件下,正则化方法的一类错误率比Logistic回归方法低。在DIF项目比例为20%时,正则化方法的检测效果优于Logistic回归方法。2)正则化方法对0.3的DIF值不敏感,检验力低。3)两种方法的一类错误率随着样本量增加、DIF值增加而增加,检验力随着样本量增加、DIF值增加、DIF项目比例减小而增加。将正则化方法应用于PISA2012数学测验数据,进行连续协变量下的DIF检测及正则化方法的实际应用,结果也发现正则化方法相比于Logistic方法可以更好地控制一类错误率。 展开更多
关键词 项目功能差异 连续协变量 正则化 LOGISTIC回归 PISA2012
下载PDF
一类包含广义Mittag-Leffler函数的积分算子的从属与超从属结果
18
作者 王小元 刘亚娟 《Chinese Quarterly Journal of Mathematics》 2023年第4期379-391,共13页
In the paper,by making use of the principle of subordination between analytic functions with the multiplier transforms defined by generalized Mittag-Leffler function,the authors investigate subclasses of univalent ana... In the paper,by making use of the principle of subordination between analytic functions with the multiplier transforms defined by generalized Mittag-Leffler function,the authors investigate subclasses of univalent analytic functions,such as starlike functions,convex functions,close-to-convex functions and quasiconvex functions.Several inclusion relationships,inequality properties,subordination and superordination results associated with the multiplier transforms are proved and the sandwich-type results are also obtained. 展开更多
关键词 Analytic functions Mittag-Leffler function Differential subordination and differential superordination Hadamard product(or Convolution)
下载PDF
一类中立型泛函微分方程周期解问题 被引量:7
19
作者 鲁世平 葛渭高 郑祖庥 《数学年刊(A辑)》 CSCD 北大核心 2004年第5期645-652,共8页
本文利用Fourier级数理论和Mawhin重合度拓展定理研究一类中立型泛函微分方程的周期解存在性问题.在其对应的特征方程具有零特征根的条件下,得到了周期解存在性的新结果.
关键词 中立型泛函微分方程 周期解 FOURIER级数 特征根 特征方程 定理 存在性 问题 拓展 条件
下载PDF
微分光谱连续小波系数估测雅氏落叶松尺蠖危害下的落叶松失叶率 被引量:7
20
作者 黄晓君 颉耀文 +3 位作者 包玉海 包刚 青松 包玉龙 《光谱学与光谱分析》 SCIE EI CAS CSCD 北大核心 2019年第9期2732-2738,共7页
害虫引起的林木失叶会严重威胁森林健康。森林虫害遥感监测与评价中快速、准确获取失叶信息十分重要。基于此,针对雅氏落叶松尺蠖引起的落叶松失叶灾象,在蒙古国开展受害林木光谱测量和失叶率估测试验。首先通过光谱实测数据的处理,得... 害虫引起的林木失叶会严重威胁森林健康。森林虫害遥感监测与评价中快速、准确获取失叶信息十分重要。基于此,针对雅氏落叶松尺蠖引起的落叶松失叶灾象,在蒙古国开展受害林木光谱测量和失叶率估测试验。首先通过光谱实测数据的处理,得到微分光谱反射率(DSR,对光谱反射率求一阶导数)和微分光谱连续小波系数(DSR-CWC,利用Biorthogonal,Coiflets,Daubechies和Symlets等4种小波系的36个母小波基函数对DSR进行连续小波变换),分析DSR和DSR-CWC对失叶率的敏感性,进而借助MATLAB的Findpeaks(Fp)函数自动寻找DSR和DSR-CWC的敏感波段并确定其对应的敏感特征,然后利用连续投影算法(SPA)对敏感特征进行降维处理,最后利用敏感特征建立偏最小二乘回归(PLSR)和支持向量机回归(SVMR)失叶率估测模型,并与逐步多元线性回归(SMLR)模型进行比较。研究结果表明:①DSR-CWC与DSR相比,对失叶率变化的敏感性更显著且敏感波段亦较多,其敏感波段主要分布于三个吸收谷(440~515,630~760和1420~1470nm)和三个反射峰(516~620,761~1000和1548~1610nm)范围内。说明DSR-CWC能够增强光谱反射和吸收特征。②Fp与SPA结合模式(Fp-SPA)不仅能够快速、客观选择敏感特征,而且对特征有效降维,是一种光谱敏感特征选择的有效方法。③4种小波系的最优母小波基分别为bior2.4,coif2,db1和sym6,其中db1的失叶率估测性能最稳定,精度最高。④对DSR进行连续小波变换能够提高失叶率估测精度,在DSR-CWC中db1-PLSR模型(R2M=0.9340,RMSEM=0.0890)提高的最为显著,比DSR-PLSR的R2M提高了0.0475并且比DSR-PLSR的RMSEM降低了0.0249。⑤利用DSR-CWC建立的PLSR和SVMR模型估测精度类似,其精度优于SMLR模型。可见,DSR-CWC比DSR失叶率估测更有潜力,可为森林虫害遥感监测中提供重要参考。 展开更多
关键词 雅氏落叶松尺蠖 落叶松失叶率 微分光谱连续小波系数 Findpeaks函数 连续投影算法
下载PDF
上一页 1 2 16 下一页 到第
使用帮助 返回顶部