共查询到20条相似文献,搜索用时 296 毫秒
1.
Cui Zhenwen 《分析论及其应用》1996,12(4):67-80
In this paper it is studied that the generated theory of wave recursive interpolation of uniform T-subdivi-ston scheme include wave parameter.The paper analyses the convergence of sequences of control polygons produced by wave recursive interpolation T-subdivision scheme of the formj=l,2,…,T-1;m=O,l,…,nTk;k=0,l,2,…,and differentiability of the limit curve. 相似文献
2.
For
the mapping
is onto R. It was shown by G. Boole in the 1850's that
We give an n-dimensional analogue of this result. The proof makes use of the Griffiths–Harris residue theorem from algebraic geometry. 相似文献
3.
In this paper, we have proposed an upper bound for the largest Z-eigenvalue of an irreducible weakly symmetric and nonnegative tensor, which is called the Brauer upper bound:■where■ As applications, a bound on the Z-spectral radius of uniform hypergraphs is presented. 相似文献
4.
Zhi Ting Xu 《数学学报(英文版)》2010,26(11):2165-2178
We obtain some new Kamenev-type oscillation theorems for the second order semilinear elliptic differential equation with damping N ∑i,j=1Di[aij(x)Djy]+N∑i=1bi(x)Diy+c(x)f(y)=0 under quite general assumptions. These results are extensions of the recent results of Sun [Sun, Y. G.: New Kamenev-type oscillation criteria of second order nonlinear differential equations with damping. J. Math. Anal. Appl., 291, 341-351 (2004)] in a natural way. In particular, we do not impose any additional conditions on the damped functions bi (x) except the continuity. Several examples are given to illustrate the main results. 相似文献
5.
V. Zh. Dumanyan 《Journal of Contemporary Mathematical Analysis (Armenian Academy of Sciences)》2010,45(1):26-42
The paper suggests some conditions on the lower order terms, which provide that the solution of the Dirichlet problem for
the general elliptic equation of the second order
$
\begin{gathered}
- \sum\limits_{i,j = 1}^n {\left( {a_{i j} \left( x \right)u_{x_i } } \right)_{x_j } + } \sum\limits_{i = 1}^n {b_i \left( x \right)u_{x_i } - } \sum\limits_{i = 1}^n {\left( {c_i \left( x \right)u} \right)_{x_i } + d\left( x \right)u = f\left( x \right) - divF\left( x \right), x \in Q,} \hfill \\
\left. u \right|_{\partial Q} = u_0 \in L_2 \left( {\partial Q} \right) \hfill \\
\end{gathered}
$
\begin{gathered}
- \sum\limits_{i,j = 1}^n {\left( {a_{i j} \left( x \right)u_{x_i } } \right)_{x_j } + } \sum\limits_{i = 1}^n {b_i \left( x \right)u_{x_i } - } \sum\limits_{i = 1}^n {\left( {c_i \left( x \right)u} \right)_{x_i } + d\left( x \right)u = f\left( x \right) - divF\left( x \right), x \in Q,} \hfill \\
\left. u \right|_{\partial Q} = u_0 \in L_2 \left( {\partial Q} \right) \hfill \\
\end{gathered}
相似文献
6.
Finbarr Holland 《Proceedings of the American Mathematical Society》2007,135(9):2915-2920
As a consequence of a more general statement proved in the paper, it is deduced that, if , and , then
7.
We consider the properties on solutions of some q-difference equations of the form ∑ n j=0 aj(z)f(qj z)=an+1(z), where a0(z),..., an+1(z) are meromorphic functions, a0(z)an(z) ≠ 0 and q ∈ C such that 0 〈 |q| ≤ 1. We give estimates on the upper bound for the length of the gap in the power series of entire solutions of (*) when the coefficients a0(z),..., an+1(z) are polynomials and 0 〈 |q| 〈 1. For some special cases, we give estimates of growth of f(z). And we also show that the case 0 〈 |q| 〈 1 is different from the case |q|=1. 相似文献
8.
设A∈C~(m×n),B∈C~(m×p)及四个矩阵方程:1)AGA=A,2)GAG=G,3)(AG)~*=AG,4)(GA)~*=GA如果G满足上述方程i),j),…k),则称G为(ij…k)型逆或penrose型广义逆,简称广义逆,并记为A(ij…k).其全体记为A{ij…k},利用矩阵广义逆的理论研究了下列两类等式成立的的充要条件:I)其中α+β=1,α>0,β>0,1≤i
9.
假设E为一致凸Banach空间,K为E的非空闭凸子集且为E的非扩张收缩,P为非扩张收缩映像.{Ti:i=1,2,…,N}:K→E为非扩张映像且F(T)=∩ from i=1 to N F(Ti)≠■.定义{xn}如下:x0∈K,xn=P(αnxn-1+(1-αn)TnP[βnxn-1+(1-βn)Tnxn]),n≥1,这里{αn},{βn}为[δ,1-δ]中的实序列,其中δ∈(0,1).若{Ti:i=1,2,…,N}满足条件(B),则{xn}强收敛于x*∈F(T). 相似文献
10.
F. Merdivenci Atici Alberto Cabada Juan B. Ferreiro 《Journal of Difference Equations and Applications》2013,19(4):357-370
In this paper, we establish comparison results (maximum principles) which allow us to use the monotone method and the method of upper and lower solutions in order to build convergent sequences to the solutions of difference equations of the type j u k = f k , u k +1 , max l ] { k m h +1,…, k +1} u l , k ] I , u 0 = u T , with j u k = u k +1 m u k , I ={0,1,…, T m 1} and f ] C ( I 2 R 2 R , R ). 相似文献
11.
Václav Tryhuk 《Czechoslovak Mathematical Journal》2000,50(3):519-529
The paper describes the general form of an ordinary differential equation of an order n + 1 (n ≥ 1) which allows a nontrivial global transformation consisting of the change of the independent variable and of a nonvanishing factor. A result given by J. Aczél is generalized. A functional equation of the form $f\left( {s,w_{00} \upsilon _0 ,...,\sum\limits_{j = 0}^n {w_{nj\upsilon _j } } } \right) = \sum\limits_{j = 0}^n {w_{n + 1j\upsilon j} + w_{n + 1n + 1} f\left( {x,\upsilon ,\upsilon _1 ,...,\upsilon _n } \right),}$ where $w_{n + 10} = h\left( {s,x,x_1 ,u,u_1 ,...,u_n } \right),w_{n + 11} = g\left( {s,x,x_1 ,...,x_n ,u,u_1 ,...,u_n } \right){\text{ and }}w_{ij} = a_{ij} \left( {x_i ,...,x_{i - j + 1} ,u,u_1 ,...,u_{i - j} } \right)$ for the given functions a ij is solved on $\mathbb{R},u \ne {\text{0}}$ . 相似文献
12.
S. A. Aldashev 《Ukrainian Mathematical Journal》1991,43(4):379-384
For the linear hyperbolic equations $$\sum\limits_{i,j = 1}^{m + 1} {a_{ij} \left( {x,x_{m + 1} } \right)u_{x_i x_j } + \sum\limits_{i = 1}^{m + 1} {a_i \left( {x,x_{m + 1} } \right)u_{x_i } + c\left( {x,x_{m + 1} } \right)u = 0,x = \left( {x_1 ,...,x_m } \right)} ,} m \geqslant 2,$$ the correctness of multidimensional analogues of the problems of Darboux and Goursat is established and a theorem on the uniqueness of a solution of the Cauchy characteristic problem is proved. 相似文献
13.
Semigroup Forum - We analyze the convergence of the following type of series $$\begin{aligned} T_N f(n)=\sum _{j=N_1}^{N_2} v_j\Big (e^{a_{j+1}{\varDelta }_d} f(n)-e^{a_{j}{\varDelta }_d} f(n)\Big... 相似文献
14.
David J. Grabiner 《Monatshefte für Mathematik》1992,114(1):35-61
A multidimensional continued fraction algorithm is a generalization of the ordinary continued fraction algorithm which approximates a vector η=(y 1,...,y n ) by a sequence of vectors \(\left( {\frac{{a_{j,1} }}{{a_{j,n + 1} }}, \ldots ,\frac{{a_{j,n} }}{{a_{j,n + 1} }}} \right)\) . If 1,y 1,...,y n are linearly independent over the rationals, then we say that the expansion of η isstrongly convergent if $$\mathop {\lim }\limits_{j \to \infty } \left| {\left( {\frac{{a_{j,1} }}{{a_{j,n + 1} }}, \ldots ,\frac{{a_{j,n} }}{{a_{j,n + 1} }}} \right) - \eta } \right| = 0.$$ This means that the algorithm converges at an asymptotically faster rate than would be guaranteed just by picking a denominator at random. The ordinary continued fraction algorithm can be defined using the Farey sequence, approximating a number by the endpoints of intervals which contain it. Analogously, we can define a Farey netF n, m to be a triangulation of the set of all vectors \(\left( {\frac{{a_1 }}{{a_{n + 1} }}, \ldots ,\frac{{a_n }}{{a_{n + 1} }}} \right)\) witha n+1 ≤m into simplices of determinant ±1, and use this algorithm to define a multidimensional continued fraction for η in which the approximations are the vertices of the simplices containing η in a sequence of Farey nets. The concept of a Farey net was proposed by A. Hurwitz, and R. Mönkemeyer developed a specific continued fraction algorithm based on it. We show that Mönkemeyer's algorithm discovers dependencies among the coordinates of η in two dimensions, but that no continued fraction algorithm based on Farey nets can discover dependencies in three or more dimensions, and none can be strongly convergent, even in two dimensions. Thus there are no good multidimensional algorithms based on Farey nets. 相似文献
15.
A. A. Žensykbaev 《Analysis Mathematica》1981,7(4):303-318
Найдены методы восст ановления интеграла по информации $$I\left( f \right) = \left\{ {f^{(j)} \left( {x_i } \right)\left( {j = 0, ..., \gamma _i - 1; i = 1, ..., n; 1 \leqq \gamma _i \leqq r; \gamma _i + ... + \gamma _n \leqq N} \right.} \right\},$$ оптимальные на класс ахW p r ,r=1,2,...; 1≦p≦∞. Это позволило, в частност и, получить наилучшие для классаW p r квадратурные форму лы вида $$\mathop \smallint \limits_0^1 f\left( x \right)dx = \mathop \Sigma \limits_{i = 1}^n \mathop \Sigma \limits_{j = 1}^{\gamma _i - 1} a_{ij} f^{(j)} \left( {x_i } \right) + \mathop \Sigma \limits_{j = 1}^{[{r \mathord{\left/ {\vphantom {r 2}} \right. \kern-\nulldelimiterspace} 2}]} b_j f^{(2j - 1)} \left( 0 \right) + \mathop \Sigma \limits_{k = 1}^{[{r \mathord{\left/ {\vphantom {r 2}} \right. \kern-\nulldelimiterspace} 2}]} c_k f^{(2k - 1)} \left( 1 \right) + R\left( f \right)$$ И $$\mathop \smallint \limits_0^1 f\left( x \right)dx = af\left( 0 \right) + \mathop \Sigma \limits_{i = 1}^n \mathop \Sigma \limits_{j = 0}^{\gamma _i - 1} a_{ij} f^{(j)} \left( {x_i } \right) + bf\left( 1 \right) + \mathop \Sigma \limits_{j = 1}^{[{r \mathord{\left/ {\vphantom {r 2}} \right. \kern-\nulldelimiterspace} 2}]} b_j f^{(2j - 1)} \left( 0 \right) + \mathop \Sigma \limits_{k = 1}^{[{r \mathord{\left/ {\vphantom {r 2}} \right. \kern-\nulldelimiterspace} 2}]} c_k f^{(2k - 1)} \left( 1 \right) + R\left( f \right).$$ 相似文献
16.
Astrid Baumann 《Aequationes Mathematicae》2003,65(3):201-235
Summary. Let $\widehat{\widehat T}_n$ and $\overline U_n$ denote the modified Chebyshev polynomials defined by $\widehat{\widehat T}_n (x) = {T_{2n + 1} \left(\sqrt{x + 3 \over 4} \right) \over \sqrt{x + 3 \over 4}}, \quad \overline U_{n}(x) = U_{n} \left({x + 1 \over 2}\right) \qquad (n \in \mathbb{N}_{0},\ x \in \mathbb{R}).$ For all $n \in \mathbb{N}_{0}$ define $\widehat{\widehat T}_{-(n + 1)} = \widehat{\widehat T}_n$ and $\overline U_{-(n + 2)} = - \overline U_n$, furthermore $\overline U_{-1} = 0$. In this paper, summation formulae for sums of type $\sum\limits^{+\infty}_{k = -\infty} \mathbf a_{\mathbf k}(\nu; x)$ are given, where
$\bigl(\mathbf a_{\mathbf k}(\nu; x)\bigr)^{-1} = (-1)^k \cdot \Bigl( x \cdot \widehat{\widehat T}_{\left[k + 1 \over 2\right] - 1} (\nu) +\widehat{\widehat T}_{\left[k + 1 \over 2\right]}(\nu)\Bigr) \cdot \Bigl(x \cdot \overline U_{\left[k \over 2\right] - 1} (\nu) + \overline U_{\left[k \over 2\right]} (\nu)\Bigr)$ with real constants $ x, \nu $. The above sums will turn out to be telescope sums. They appear in connection with projective geometry. The directed euclidean measures of the line segments of a projective scale form a sequence of type $(\mathbf a_{\mathbf k} (\nu;x))_{k \in \mathbb{Z}}$ where $ \nu $ is the cross-ratio of the scale, and x is the ratio of two consecutive line segments once chosen. In case of hyperbolic $(\nu \in \mathbb{R} \setminus] - 3,1[)$ and parabolic $\nu = -3$ scales, the formula $\sum\limits^{+\infty}_{k = -\infty} \mathbf a_{\mathbf k} (\nu; x) = {\frac{1}{x - q_{{+}\atop(-)}}} - {\frac{1}{x - q_{{-}\atop(+)}}} \eqno (1)$ holds for $\nu > 1$ (resp. $\nu \leq - 3$), unless the scale is geometric, that is unless $x = q_+$ or
$x = q_-$. By $q_{\pm} = {-(\nu + 1) \pm \sqrt{(\nu - 1)(\nu + 3)} \over 2}$ we denote the quotient of the associated geometric sequence.
相似文献
17.
Václav Tryhuk 《Czechoslovak Mathematical Journal》2000,50(3):509-518
The paper describes the general form of an ordinary differential equation of the order n + 1 (n 1) which allows a nontrivial global transformation consisting of the change of the independent variable. A result given by J. Aczél is generalized. A functional equation of the form
where
are given functions,
is solved on
. 相似文献
18.
л. Д. кУДРьВцЕВ 《Analysis Mathematica》1992,18(3):223-236
ДОкАжАНО, ЧтО Дль тОгО, ЧтОБы Дльr РАж ДИФФЕРЕНцИРУЕМОИ НА пРОМЕжУткЕ [А, + ∞) ФУНкцИИf сУЩЕстВОВА л тАкОИ МНОгОЧлЕН
19.
Zhi-ting Xu 《应用数学学报(英文版)》2007,23(4):569-578
Some oscillation theorems are given for the nonlinear second order elliptic equationsum from i,j=1 to N D_i[a_(ij)(x)Ψ(y)||▽y||~(p-2)D_(jy)] c(x)f(y)=0.The results are extensions of modified Riccati techniques and include recent results of Usami. 相似文献
20.
Giuseppe Maria Coclite Angelo Favini Gisèle Ruiz Goldstein Jerome A. Goldstein Silvia Romanelli 《Semigroup Forum》2008,77(1):101-108
The solution u of the well-posed problem
|