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101.
D. Cárdenas-Morales 《Mathematics and computers in simulation》2011,81(10):2098-2102
In this paper we present a new result on the saturation of sequences of linear operators in a multivariate and simultaneous setting. Specifically, a small o saturation result is obtained for the partial derivatives of the classical Bernstein bivariate operators on the unit simplex. Solutions of boundary value problems for certain partial differential equations of elliptic type play an important role. 相似文献
102.
In this paper we present the sequence of linear Bernstein-type operators defined for f∈C[0,1] by Bn(f°τ−1)°τ, Bn being the classical Bernstein operators and τ being any function that is continuously differentiable ∞ times on [0,1], such that τ(0)=0, τ(1)=1 and τ′(x)>0 for x∈[0,1]. We investigate its shape preserving and convergence properties, as well as its asymptotic behavior and saturation. Moreover, these operators and others of King type are compared with each other and with Bn. We present as an interesting byproduct sequences of positive linear operators of polynomial type with nice geometric shape preserving properties, which converge to the identity, which in a certain sense improve Bn in approximating a number of increasing functions, and which, apart from the constant functions, fix suitable polynomials of a prescribed degree. The notion of convexity with respect to τ plays an important role. 相似文献
103.
In this paper, according to classic -matrix method, integral–differential inequality technique and Ito formula, we study asymptotic behavior in mean square sense of stochastic neural networks with infinitely distributed delays by establishing a generalized Halanay inequality. This is a new means for investigating asymptotic behavior of stochastic differential equation. Some useful results are derived. Especially, our methods can be extended to research p-moment asymptotic behavior easily. At last, example and simulations demonstrate the power of our methods. 相似文献
104.
In this paper, a Galerkin finite element scheme to approximate the time–space fractional diffusion equation is studied. Firstly, the fractional diffusion equation is transformed into a fractional Volterra integro-differential equation. And a second-order fractional trapezoidal formula is used to approach the time fractional integral. Then a Galerkin finite element method is introduced in space direction, where the semi-discretization scheme and fully discrete scheme are given separately. The stability analysis of semi-discretization scheme is discussed in detail. Furthermore, convergence analysis of semi-discretization scheme and fully discrete scheme are given in details. Finally, two numerical examples are displayed to demonstrate the effectiveness of the proposed method. 相似文献
105.
具有测量数据丢失的离散不确定时滞系统鲁棒Kalman滤波 总被引:1,自引:0,他引:1
研究了具有测量数据丢失的离散不确定时滞系统鲁棒Kalman滤波问题, 其中时延存在于系统状态和观测值中. 模型的不确定性通过在系统矩阵中引入随机参数扰动来表示, 测量数据丢失现象则通过一个满足Bernoulli分布且统计特性已知的随机变量来描述. 基于最小方差估计准则, 利用射影性质和递归射影公式得到一个新的滤波器设计方法, 并且保证了滤波器的维数与原系统相等. 与传统的状态增广方法相比, 当时延比较大时, 该方法可以有效降低计算量. 最后, 给出一个仿真例子说明所提方法的有效性. 相似文献
106.
107.
Ana Gàl 《Computational Complexity》2001,10(4):277-296
We give a characterization of span program size by a
combinatorial-algebraic measure. The measure we consider is a generalization
of a measure on covers which has been used to prove lower
bounds on formula size and has also been studied with respect to communication
complexity.?In the monotone case our new methods yield lower bounds for
the monotone span program complexity of explicit Boolean functions in
n variables over arbitrary fields, improving the previous lower bounds
on monotone span program size. Our characterization of span program
size implies that any matrix with superpolynomial separation between
its rank and cover number can be used to obtain superpolynomial lower
bounds on monotone span program size. We also identify a property
of bipartite graphs that is suficient for constructing Boolean functions
with large monotone span program complexity.
Received: September 30, 2000. 相似文献
108.
误差最小的计算机插补原理 总被引:1,自引:0,他引:1
吴庆标 《计算机辅助设计与图形学学报》2000,12(3):174-178
从包括的思想出发,解决了对单调光滑函数曲线构造一个带域,在此带域中所确定的绘图路径是误差最小的。另外,文中应用带域提出了一种误差最小插补法,得到递推公式,每次要计算的是进给步数,跟过去一贯采用的每走一步都要计算判别函数的传统方法比较,具有较强的优越性,最后给出计算实例。 相似文献
109.
再访GI/M/1排队 总被引:2,自引:2,他引:0
通过构造两个向量马氏过程重新探讨了GI/M/1排队,某些新结果如忙期和闲期的
联合分布被得到了.这一方法容易推广到服务时间为无限位相型分布的GI/SPH/1排队. 相似文献
110.