共查询到19条相似文献，搜索用时 171 毫秒
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讨论了带有泛分解态射的加权Moore-Penros逆,并给出了加权Moore-Penros逆存在的几个充要条件以及若干性质. 相似文献
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《科技通报》2018,(11)
R是实数域,SK_n(R)表示R上n×n反对称矩阵空间(其中n≥4,并且n为偶数),本文刻画了SK_n(R)到自身满足f(A)f(B)f(C)=f(C)f(A)f(B)当且仅当ABC=CAB的加法满射f的形式,并且又刻画了SK_n(R)到自身满足g(A_1)g(A_2)…g(A_(2k+1))=g(A_(t1)/sub)g(A_(t2)/sub)…g(A_(t2k+1)/sub)当且仅当A_1A_2…A_(2k+1)=A_(t1)/subA_(t2)/sub…A_(t2k+1)/sub的加法满射g的形式,其中k≥1,k∈Z,t_1,t_2,…,t_(2k+1)是1,2,…,2k+1的任意排列。 相似文献
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关于环上矩阵的Γαβ-广义逆 总被引：1，自引：0，他引：1
研究环上矩阵的Гαβ-广义逆和Гαβ-Moore-Penrose逆,得到带有对合反自同构的有单位元的结合环R上的一类可分解矩阵的Гαβ-广义逆和Гαβ-Moore-Penrose逆存在的充要条件及表达式,推广了以往的相应结果。 相似文献
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讨论矩阵的Γα-Moore-Penrose逆.给出了矩阵的Γα-Moore-Penrose逆存在的几个充要条件以及Γα-Moore-Penrose逆的几个计算公式. 相似文献
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讨论了一阶常微分方程M(X,Y)dx+N(X,Y)dy=0的积分因子问题,给出了一阶常微分方程有形如μ(f(x)g(y))的积分因子的一个充要条件和计算公式。 相似文献
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讨论矩阵的Гα-Moore—Penrose逆。给出了矩阵的Гα-Moore—Penrose逆存在的几个充要条件以及Гα-Moore—Penrose逆的几个计算公式。 相似文献
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本文给出下列二阶非线性时滞微分方程振动的充要条件x″(t) g[x′(t-τ(t))]f[x(t-σ)]=0和[a(t)x′(t)]′ p(t)g[x′(t-τ(t))]f[x(t-σ)]=0其中τ(t)≥0,σ是正常数且σ≤τ(t).对于具有强迫项的时滞微分方程[a(t)x′(t)]′ p(t)f[x(t-σ)]=g(t)我们给出振动的充分条件. 相似文献
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定义了无限初等方阵和无限方阵的初等变换，利用无限初等方阵和无限方阵的初等变换，证明了除环R上行有限无限方阵A有左(右)逆的充要条件是对A进行有限次第二、三类行(列)初等变换可将A的行向量化为标准单位向量，进而给出了rcf无限方阵可逆的充要条件。 相似文献
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In this note, the problem of solution to the matrix equation AX+XTC=B is considered by the Moore-Penrose generalized inverse matrix. A general solution to this equation is obtained. At the same time, some useful conclusions are made, which play important roles in the linear system theories and applications. 相似文献
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运用M-P广义逆理论,研究了桁架结构的非线性homologous设计问题。将homologous变形约束条件引入结构基本方程,运用M-P广义逆矩阵的性质,将基本方程解的存在条件表示为含可变节点坐标变量的非线性方程组,通过求解该非线性方程组找到了满足homologous变形约束要求的解,并为此推导了AA (A为任意矩阵,A 为A的M-P广义逆矩阵)求偏导数的显式表达。最后的算例验证了本方法的正确性和有效性。 相似文献
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The difficulties in solving Fredholm integral equations of the first kind are well known. A classical method has been to convert the equation into a set of m linear algebraic equations in n unknowns (m?n). For computational convenience, it is customary to force m = n and solve the resulting ill-conditioned system using one technique or other. In the general case, a feasible solution, if it exists, can be found by determining the generalized inverse of the coefficient matrix. One method of finding the generalized inverse is to reformulate the problem and observe the steady state response of a system of ordinary differential equations with prescribed initial conditions. Results obtained from this reformulation are found to be comparable in quality to those obtained earlier by other methods. Analog and digital computer implementations are discussed. 相似文献
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凑微分法和分部积分法是求解不定积分的两种重要方法,这两种方法都适用于形如乙∫f（x）g（x）dx的积分,都有凑微分的过程,学生容易混淆。针对这种情况,本文提出了一种简单、快速、易于学生掌握的方法——＂拆＂、＂判＂、＂选＂、＂凑＂四步法,帮助学生快速找到正确的积分方法和要凑的微分因子,从而达到快速、准确解题的目的。 相似文献
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尽管近期大量学者验证了外部知识异质度对企业创新绩效具有倒U型曲线效应,但却没有能够厘清这一效应的内生性机制及其形成原因。本研究基于知识重构和吸收能力的视角,通过采集和分析来自江苏、浙江和上海的261个创新型样本企业问卷数据,识别外部知识异质度对企业创新绩效倒U型曲线效应的形成机制。结果表明:外部知识异质度通过促进知识重构正向影响创新绩效,却通过弱化吸收能力反向影响创新绩效;这两种效果相反的中介机制导致外部知识异质度与创新绩效之间产生了倒U型曲线关系。这一发现揭示了企业外部知识异质度对创新绩效影响的内在机理,进一步发展了主流文献的相关研究。 相似文献
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J.M. Lowerre 《Journal of The Franklin Institute》1977,303(6):517-526
For the linear statistical model y = Xb + e, X of full column rank estimates of b of the form (C + X′X)+X′y are studied, where C commutes with X′X and Q+ is the Moore-Penrose inverse of Q. Such estimators may have smaller mean square error, component by component than does the least squares estimator. It is shown that this class of estimators is equivalent to two apparently different classes considered by other authors. It is also shown that there is no C such that (C + X′X)+X′Y = My, in which My has the smallest mean square error, component by component. Two criteria, other than tmse, are suggested for selecting C. Each leads to an estimator independent of the unknown b and σ2. Subsequently, comparisons are made between estimators in which the C matrices are functions of a parameter k. Finally, it is shown for the no intercept model that standardizing, using a biased estimate for the transformed parameter vector, and retransforming to the original units yields an estimator with larger tmse than the least squares estimator. 相似文献
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This paper deals with questions concerning a transformation-based form of the Cauchy-Schwarz inequality (f,f)(g,g) ? (f,g)(g,f) where f and g are complex vectors. In the case of a linear transformation restricted to be real a refinement of the inequality can be given. The classes of transformation matrices are defined which impose the equality signs in the above inequalities and thus minimize their left hand sides. A diagonalization procedure provides the determination of a special canonical solution to the desired linear transformation and enables the explicit definition of the remaining degree of freedom. 相似文献
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Przemys?aw Herman 《Journal of The Franklin Institute》2005,342(1):25-38
In this paper a proposition of inverse dynamics control for a manipulator using the unnormalized quasi-velocities (UQV) is presented. These quasi-velocities introduced by Jain and Rodriguez (IEEE Trans. Robotics Automat,16, 2000, 517; 11, 1995, 571) are used here to show some performance obtained from the controller. It is shown that for a two d.o.f. planar manipulator one can assume UQV which are integrable with respect to time. The introduced controller in terms of UQV is exponentially convergent. As a consequence of using UQV inverse dynamics control, one can notice some interesting properties in comparison with the classical controller. Additionally, some geometrical interpretation based on Riemannian geometry is given. 相似文献
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Said Abboudi 《Journal of The Franklin Institute》2011,348(7):1192-1207
A simultaneous estimation of two convective boundary conditions problem of a two-dimensional rectangular fin is proposed by numerical approach. The aim is to estimate the evolution of the distributions of the unknown heat transfer coefficients from the transient temperature histories taken with several sensors inside a two-dimensional fin. The estimation algorithm of this inverse heat conduction problem is based on the iterative regularization method and on the conjugate gradient method. An optimal choice of the vector of the descent parameters is used in this study and shows an increase in the convergence rate. The effects of some parameters (sensor number, position, measurement errors) on the inverse solutions are discussed. 相似文献