输入方波信号的过阻尼谐振子的随机共振

计算了在输入方波信号情况下过阻尼谐振子的输出功率谱和信噪比,详细讨论了相应的随机共振现象,并与输入余弦信号情况进行对比.研究发现:它们均出现随机共振现象,且均存在共振和抑制并存的现象.但这一并存现象,在两模型中分别出现于不同的共振曲线. 关键词： 过阻尼谐振子 随机共振 方波信号     

结构光测量相位波动误差补偿方法研究

在计算机仿真分析投影仪伽马非线性特性对包裹相位波动误差影响的基础上,提出一种面向相移结构光测量的相位波动误差补偿方法.该方法采用二次多项式最小二乘拟合的方法近似输出条纹光强分布,实现包裹相位波动误差的补偿,减小投影仪非线性导致的系统测量误差.此方法简单,运算量小,不依赖环境光源及投影仪、摄像机具体参数,具有很强的通用性...     

Area integral functions for sectorial operators on L spaces

Area integral functions are introduced for sectorial operators on L^p-spaces. We establish the equivalence between the square and area integral functions for sectorial operators on L^p spaces. This follows that the results of Cowling, Doust, McIntosh, Yagi, and Le Merdy on H^infin functional calculus of sectorial operators on L^p-spaces hold true when the square functions are replaced by the area integral functions.     

L（1, 2）-edge-labelings for lattices

For a graph G and two positive integers j and k, an m-L(j, k)-edge-labeling of G is an assignment on the edges to the set {0, 1, 2,..., m}, such that adjacent edges which receive labels differ at least by j, and edges which are distance two apart receive labels differ at least by kThe λ j,k-number of G is the minimum m such that an m-L(j, k)-edge-labeling is admitted by GIn this article, the L(1, 2)-edge-labeling for the hexagonal lattice, the square lattice and the triangular lattice are studied, and the bounds for λ j,k-numbers of these graphs are obtained.     

Calderón–Zygmund Operators in the Bessel Setting for All Possible Type Indices

We show that many harmonic analysis operators in the Bessel setting,including maximal operators,Littlewood–Paley–Stein type square functions,multipliers of Laplace or Laplace–Stieltjes transform type and Riesz transforms are,or can be viewed as,Calderón–Zygmund operators for all possible values of type parameter λ in this context.This extends results existing in the literature,but being justified only for a restricted range of λ.     

Numerical inversion of laplace transform via wavelet in partial differential equations

This article presents a rational Haar wavelet operational method for solving the inverse Laplace transform problem and improves inherent errors from irrational Haar wavelet. The approach is thus straightforward, rather simple and suitable for computer programming. We define that P is the operational matrix for integration of the orthogonal Haar wavelet. Simultaneously, simplify the formulae of listing table (Chen et al., Journal of The Franklin Institute 303 (1977), 267–284) to a minimum expression and obtain the optimal operation speed. The local property of Haar wavelet is fully applied to shorten the calculation process in the task. The operational method presented in this article owns the advantages of simpler computation as well as broad application. We still can obtain satisfying solution even under large matrix. Moreover, we do not have numerically unstable problems. © 2013 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 30: 536–549, 2014     

与年龄相关的模糊随机种群扩散系统的指数稳定性

讨论了一类与年龄相关的模糊随机种群扩散系统,系统受两种不确定性因素的影响,即随机和模糊.在有界和Lipschitz条件下,利用Ito公式和Gronwall引理,建立了均方意义下与年龄相关的模糊随机种群扩散系统指数稳定性的判定准则并通过数值例子对所给出的结论进行了验证.     

运用多目标规划优化功放的预失真模型

预失真技术是克服功率放大器非线性失真的一种非常有效的方法.许多研究者从数学建模的思想角度出发,建立了关于功放与预失真的各类级数模型,以实现线性增益输出.但是在应用通信系统中,这些模型不能有效地动态实现功放效率尽可能高的要求.在和记忆多项式模型的基础上,创新地运用多目标规划的方法优化功放的预失真模型.在满足一定的线性化输出的同时,尽可能地得到更高的功放效率,而且能同时计算出增益系数与模型参数.对于数据量为1000的无记忆功放得到增益倍数为1.82649,预失真模型的NMSE值为-41.5633.数据量为73920的有记忆功放得到增益倍数为9.5969,预失真模型的NMSE值为-24.3682.     

A least‐square weighted residual method for level set formulation

In this paper, a least‐square weighted residual method (LSWRM) for level set (LS) formulation is introduced to achieve interface capturing in two‐dimensional (2D) and three‐dimensional (3D) problems. An LSWRM was adopted for two semi‐discretized advection and reinitialization equations of the LS formulation. The present LSWRM provided good mathematical properties such as natural numerical diffusion and the symmetry of the resulting algebraic systems for the advection and reinitialization equations. The proposed method was validated by solving some 2D and 3D benchmark problems such as those involving a rotating slotted disk, the rotation of a slotted sphere, and a time‐reversed single‐vortex flow and a deformation problem of a spherical fluid. The numerical results were compared with those obtained from essentially non‐oscillatory type formulations and particle LS methods. Further, the proposed LSWRM for the LS formulation was coupled with a splitting finite element method code to solve the incompressible Navier–Stokes equations, and then, the collapse of a 3D broken dam flow was well simulated; in the simulation, the entrapping of air and the splashing of the surge front of water were reproduced. The mass conservation of the present method was found to be satisfactory during the entire simulation. Copyright © 2011 John Wiley & Sons, Ltd.     

D[X2m]的下界估计与X2m矩阵的快速构造

本文利用有向图理论研究了Xn矩阵的特性，给出了X2m矩阵类的快速构造方法，证明了拉丁方矩阵D[X2m]数目的下界估计是：2m(2m)! ∑^mi=2[(2m)!]^2/П^ij=1Kj!П^rj=1bj!。