Closures on CPOs Form Complete Lattices

It is well known that closure operators on a complete lattice, ordered pointwise, give rise to a complete lattice, and this basic fact plays an important rôle in many fields of the semantics area, notably in domain theory and abstract interpretation. We strengthen that result by showing that closure operators on any directed-complete partial order (CPO) still form a complete lattice. An example of application in abstract interpretation theory is given.     

关于算子形式的Bohr不等式的推广

采用算子论中的方法和技巧,研究了Bohr不等式的有界线性算子形式的推广,并且给出一些算子不等式,这样对文[4-5]中的结果进行了推广.进一步研究了Bohr不等式在算子范数上的性质,推广了文[6]中的相关结果.     

A note to the integrable discretization of the mKdV and Schrödinger equations

An approach has been proposed to the integrable discretization of nonlinear evolution equations. Based on the bilinear formalism, we choose appropriate substitution from hyperbolic operator into continuous Hirota operators and obtain several new kinds of integrable system through seeking their 3-soliton solutions, such as the mKdV equation, the nonlinear Schrödinger equation and so on. By applying Adomian decompose method, we discuss the numerical analysis property to the discrete mKdV equation. In addition, we also point out the relations between the above discreted equations and some well-known equations.     

Adaptive and optimal difference operators in image processing

Differential operators are essential in many image processing applications. Previous work has shown how to compute derivatives more accurately by examining the image locally, and by applying a difference operator which is optimal for each pixel neighborhood. The proposed technique avoids the explicit computation of fitting functions, and replaces the function fitting process by a function classification process using a filter bank of feature detection templates. Both the feature detectors and the optimal difference operators have a specific shape and an associated cost, defined by a rigid mathematical structure, which can be described by Gröbner bases. This paper introduces a cost criterion to select the operator of the best approximating function class and the most appropriate template size so that the difference operator can be locally adapted to the digitized function. We describe how to obtain discrete approximates for commonly used differential operators, and illustrate how image processing applications can benefit from the adaptive selection procedure for the operators by means of two example applications: tangent computation for digitized object boundaries and the Laplacian of Gaussian edge detector.     

Formalizing non-termination of recursive programs

In applicative theories the recursion theorem provides a term which solves recursive equations. However, it is not provable that a solution obtained by is minimal. In the present paper we introduce an applicative theory in which it is possible to define a least fixed point operator. Still, our theory has a standard recursion theoretic interpretation.     

Hilbert空间中由Rosenblatt过程驱动的带有限延迟的随机发展方程

Rosenblatt过程作为一个重要的自相似随机过程,常被用来刻画非高斯随机现象．为进一步研究Rosenblatt过程 对随机现象的刻画,本文考虑由Rosenblatt过程驱动的带有限延迟的一类时间相依随机发展方程适度解的问题．在实值 可分Hilbert空间中,运用Banach不动点定理得到了Rosenblatt过程驱动的带有限延迟的随机发展方程适应解 的存在性和唯一性,并通过例子说明所得结果是有效的．     

利用1~2阶分数阶微分掩模的边缘检测

现有的分数阶微分边缘检测算子大都是基于0~1阶分数阶微分而构造,鲜有文献讨论基于1~2阶分数阶微分的边缘检测算子。为此,分析了1~2阶分数阶微分对信号的作用,基于1~2阶分数阶微分构造了一种新的边缘检测掩模算子。实验结果表明,该算子不仅优于常用整数阶微分算子,而且比现有的一些0~1阶分数阶微分算子具有更好的边缘检测效果。     

阴影检测技术在裁割机样片轮廓提取中的应用研究

阴影将导致轮廓提取时样片的轮廓发生扭曲变形以及部分轮廓的丢失,为了提高轮廓提取的准确性,提出了一种基于色度畸变和均值的局部多层次差分算子的阴影检测方法.新方法从彩色不变性和纹理相似性两个方面出发,通过阴影覆盖前后色度变化相对较小和纹理具有相似性的原理来确定阴影区域.实验结果表明：该方法能够有效去除样片周围的阴影,具有良好的性能.     

Representation of fatigue for wind turbine control

Fatigue is a critical factor in structures such as wind turbines exposed to harsh operating conditions, both in the design stage and in the control during their operation. In the present paper, the most recognized approaches to estimate the damage caused by fatigue in the component level are discussed and compared. The aim of this paper is to address the applicability of those fatigue damage estimation methods to control of wind turbines. Accordingly, for our discussion and comparison, we categorize fatigue estimation methods in a macroscopic scale as counting, spectral, stochastic and hysteresis operator methods. Copyright © 2016 John Wiley & Sons, Ltd.     

随机共振降噪下的齿轮微弱故障特征提取

针对强背景噪声下的齿轮微弱故障特征提取问题,提出了一种将级联单稳随机共振与经验模式分解(EMD)-Teager能量算子解调方法相结合的特征提取方法。首先对含噪故障信号进行随机共振输出,降噪后再进行经验模式分解,分解得到具有不同特征时间尺度的固有模态函数(IMFs),最后通过Teager能量算子解调方法求取每个有效IMF分量的幅频信息,从而提取齿轮微弱故障特征。仿真分析和实际测试结果均表明,通过随机共振降噪后,该方法能有效检测出齿轮局部损伤故障特征频率。