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31.
Let λ and μ be solid sequence spaces. For a sequence of modulus functions Φ = (ϕ k) let λ(Φ) = {x = (x
k
): (ϕk(|x
k
|)) ∈ λ}. Given another sequence of modulus functions Ψ = (ψk), we characterize the continuity of the superposition operators P
f
from λ(Φ) into μ (Ψ) for some Banach sequence spaces λ and μ under the assumptions that the moduli ϕk (k ∈ ℕ) are unbounded and the topologies on the sequence spaces λ(Φ) and μ(Ψ) are given by certain F-norms. As applications
we consider superposition operators on some multiplier sequence spaces of Maddox type.
This research was supported by Estonian Science Foundation Grant 5376. 相似文献
32.
In this paper, the impact of optical beat noise on the performance of optical fast frequency-hopping code-division multiple-access (FFH OCDMA) networks is analyzed. BCH/FFH-OCDMA to reduce the impact of optical beat noise is proposed. It is shown that, BCH/FFH-OCDMA has much better performance under the same bit rate, same chip time and same number of available wavelengths. Another advantage for BCH/FFH-OCDMA is that the code length of one-coincidence sequence will be shorter, which can greatly reduce the difficulty of fabrication for fiber gratings. 相似文献
33.
YAN Zhen-Ya 《理论物理通讯》2002,38(10)
Recently, we obtained thirteen families of Jacobian elliptic function solutions of mKdV equation by usingour extended Jacobian elliptic function expansion method. In this note, the mKdV equation is investigated and anotherthree families of new doubly periodic solutions (Jacobian elliptic function solutions) are fbund again by using a newtransformation, which and our extended Jacobian elliptic function expansion method form a new method still called theextended Jacobian elliptic function expansion method. The new method can be more powertul to be applied to othernonlinear differential equations. 相似文献
34.
在分析红外图象和视图象差异的基础上,研究了一种适用于可视图像序列的运动小目标检测算法。受目标影响的象素点具有较弱的时间相关性,即相对普通象素点有较大的时间方差,根据此特征,用管道更新的方法产生新方差图象序列,再用管道更新的方法累积,增加信噪比,然后用基于统计均值的自适应门限方法分割出目标,最后将原图象的梯度倒数作为象素点强度的加权,有效地抑制灰度突变边界的传感器噪音,保存目标点。 相似文献
35.
36.
A. V. Kel’manov L. V. Mikhailova 《Computational Mathematics and Mathematical Physics》2006,46(1):165-181
The problem of joint a posteriori detection of reference fragments in a quasi-periodic sequence and its partition into segments containing series of recurring fragments from the reference tuple is solved. It is assumed that (i) an ordered reference tuple of sequences to be detected is given, (ii) the number of desired fragments is known, (iii) the index of the sequence term corresponding to the beginning of a fragment is a deterministic (not random) value, and (iv) a sequence distorted by an additive uncorrelated Gaussian noise is available for observation. It is established that the problem consists in testing a set of hypotheses about the mean of a random Gaussian vector. The cardinality of the set grows exponentially as the vector dimension (i.e., the sequence length) increases. An efficient a posteriori algorithm producing a maximum-likelihood optimal solution to the problem is substantiated. Time and space complexity bounds related to the parameters of the problem are derived. The results of numerical simulation are presented. 相似文献
37.
Jian‐guo Tang 《Mathematical Methods in the Applied Sciences》2006,29(11):1327-1338
An implicit iterative method is applied to solving linear ill‐posed problems with perturbed operators. It is proved that the optimal convergence rate can be obtained after choosing suitable number of iterations. A generalized Morozov's discrepancy principle is proposed for the problems, and then the optimal convergence rate can also be obtained by an a posteriori strategy. The convergence results show that the algorithm is a robust regularization method. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
38.
将散射介质层在z轴方向划分成薄层,用薄层的一阶散射强度、Fourier变换和迭代方法求解散射介质整层的矢量辐射传输(VRT)方程的高阶散射解.该方法将一阶散射与高阶散射迭代结合起来,计算公式简明,可计算高阶迭代解,计算时间少.计算结果与一层均匀散射介质的VRT方程一阶Mueller矩阵解、半空间均匀散射介质二阶Mueller矩阵解、以及离散坐标-特征值特征矢量法的VRT热辐射的数值解作了全面的比较.提出并讨论了非均匀散射层主动与被动VRT方程的高阶解.本计算程序可以通用于非球形粒子多层结构及非均匀介质的散射和热辐射计算.
关键词:
VRT方程
分层
迭代解 相似文献
39.
Eckhard Steffen 《Discrete Mathematics》2004,280(1-3):191-214
Cubic bridgeless graphs with chromatic index four are called uncolorable. We introduce parameters measuring the uncolorability of those graphs and relate them to each other. For k=2,3, let ck be the maximum size of a k-colorable subgraph of a cubic graph G=(V,E). We consider r3=|E|−c3 and
. We show that on one side r3 and r2 bound each other, but on the other side that the difference between them can be arbitrarily large. We also compare them to the oddness ω of G, the smallest possible number of odd circuits in a 2-factor of G. We construct cyclically 5-edge connected cubic graphs where r3 and ω are arbitrarily far apart, and show that for each 1c<2 there is a cubic graph such that ωcr3. For k=2,3, let ζk denote the largest fraction of edges that can be k-colored. We give best possible bounds for these parameters, and relate them to each other. 相似文献
40.
Banach空间二阶周期边值问题解的存在性 总被引:2,自引:0,他引:2
利用一些比较结果,讨论了Banach空间中二阶周期边值问题解的存在性,获得了若干解的存在性与唯一性结果。 相似文献