二维线性正则变换理论及应用研究进展

线性正则变换作为经典傅里叶变换和分数阶傅里叶变换的广义形式,拥有更大的灵活性,是分析和处理非平稳信号的有力工具.同样,二维线性正则变换在处理和分析二维信号时具有良好性能.首先系统地总结了近年来二维线性正则变换的发展历程和理论研究成果,重点阐述了二维不可分离的线性正则变换的最新基础理论,包括其重要性质、采样和离散理论、快速算法、不确定性原理、特征函数等;然后介绍了二维线性正则变换在滤波器设计、图像处理等领域中的最新应用成果;最后对二维线性正则变换的发展前景做出展望.对研究者全面了解二维线性正则变换具有很好的参考价值,可以进一步促进其工程应用.     

基于Hilbert变换的LFM检测与估计

LFM(线性调频)信号是一类重要的非平稳信号,其完全被初始频率和调频斜率两个参量表征,而LFM信号的检测与估计问题是信号处理中最为重要的研究热点之一.由于调频信号在时频平面内有较好的聚集性,通常使用时频分析的方法对其进行检测和估计.线性正则变换是经典时频分布的广义形式,对LFM信号具有很好的能量聚集特性,在现有的线性正则域Hilbert变换的基础上,提出了一种不需要谱峰搜索而快速检测LFM信号和估计其参数的方法,并且通过仿真实例验证了所提出方法的优越性.     

线性流量阀的内孔设计模型

在详细分析线性流量阀工作原理的基础上,应用平面解析几何、微积分等相关概念,给出了不存在呈严格线性的流量阀的数学论证.在设计近似线性流量阀时,首先构造了"线性误差函数"用以刻画"过流面积"与角度之间的线性误差.之后在分析内孔为对称直线、对称1/2次曲线的基础上,设计出内孔为倒"S"形内孔曲线图,通过最小化线性误差函数,得到内孔曲线的最佳参数.最后针对外孔有磨损时,给出了设计方案.     

AHP中的权向量的注记

阐述了层次分析法的权向量线性 ,拟线性和非线性表示 .讨论了 AHP,模糊 AHP等模型及随机性AHP的保序性 .并给出了其有关的应用实例     

分数阶力学系统的正则变换理论

应用分数阶模型可以更准确地描述复杂系统的力学与物理行为,随着分数阶微积分在科学和工程的诸多领域的成功应用,传统的分析力学理论和方法需要拓展到含有分数阶微积分的系统.变换是分析力学研究的一个重要手段.本文研究分数阶力学系统的变换理论.基于Cuputo分数阶导数的定义,定义力学系统的Lagrange函数和Hamilton函数,在H(o|¨)lder交换关系下建立了分数阶Hamilton原理,并由分数阶Hamilton原理通过变分运算导出分数阶Hamilton正则方程;建立了分数阶力学系统的正则变换理论,给出了四种基本形式的分数阶正则变换,并通过算例说明母函数在分数阶正则变换中的作用.     

随机赋范空间算子随机范数与Hahn-Banach延拓定理

基于概率测度理论基础,研究了随机赋范空间中算子随机范数,得到了线性算子空间与线性泛函的若干随机化结果与随机化的Hahn-Banach延拓定理.结果可能成为随机泛函分析与概率论及应用的理论工具.     

两个线性模型间最优线性无偏预测的等价性

设M1和M2是两个带有预测量的线性模型,通过使用矩阵秩方法,本文给出了模型M1下预测量的最优线性无偏预测同时也是模型M2下的最优线性无偏预测的充分必要条件.作为这个结果的应用,我们给出了两个线性混合模型间最优线性无偏预测等价性的充分必要条件.     

对角型拟线性双曲组的整体经典解

本文在特征值部分线性退化、部分弱线性退化时,考察一阶拟线性对角型严格双曲组的柯西问题,当初值满足适当的条件时得到了其整体经典解的存在性.     

凸函数的若干新性质及应用

本文证明了凸函数的若干新性质 ,讨论了这些性质在求解线性与非线性不等式组和线性规划中的应用 ,为线性与非线性不等式组、线性规划的求解提供了一种新方法 .     

亚声速热射流声源模型的应用

对亚声速转捩热射流中失稳波相关的噪声产生机制进行了研究,并与冷射流中的结果进行了对比.基于时均大涡模拟(LES)流场,通过求解线性抛物化稳定性方程(LPSE)得到了失稳波的空间演化特性,然后基于LPSE的解与声比拟方法构建了射流的线性及非线性声源模型.LPSE结果表明,加热可以提高失稳波的空间增长率,使其更早达到饱和.由线性模型分析可知,加热会提高高频模态的声压级(SPL).与冷射流相比,热射流中线性模型预测的声压级与大涡模拟结果间的差距更小,表明线性机制在热射流中作用更大.在亚声速冷射流中,非线性模型在之前的研究中已经被证明可以提高声辐射效率.在当前热射流中,发现非线性模型与大涡模拟间的声压级差距被进一步的缩小,且温度相关的声源项在声辐射中发挥更重要的作用.     

Octonion short-time linear canonical transform

We investigate the octonion short-time linear canonical transform (OCSTLCT) in this paper. First, we propose the new definition of the OCSTLCT, and then several important properties of newly defined OCSTLCT, such as bounded, shift, modulation, time-frequency shift, inversion formula, and orthogonality relation, are derived based on the spectral representation of the octonion linear canonical transform (OCLCT). Second, by the Heisenberg uncertainty principle for the OCLCT and the orthogonality relation property for the OCSTLCT, the Heisenberg uncertainty principle for the OCSTLCT is established. Finally, we give an example of the OCSTLCT.     

Uncertainty principles associated with the offset linear canonical transform

As a time‐shifted and frequency‐modulated version of the linear canonical transform (LCT), the offset linear canonical transform (OLCT) provides a more general framework of most existing linear integral transforms in signal processing and optics. To study simultaneous localization of a signal and its OLCT, the classical Heisenberg's uncertainty principle has been recently generalized for the OLCT. In this paper, we complement it by presenting another two uncertainty principles, ie, Donoho‐Stark's uncertainty principle and Amrein‐Berthier‐Benedicks's uncertainty principle, for the OLCT. Moreover, we generalize the short‐time LCT to the short‐time OLCT. We likewise present Lieb's uncertainty principle for the short‐time OLCT and give a lower bound for its essential support.     

用奇异值分解方法计算具有重特征值矩阵的特征矢量

若当(Jordan)形是矩阵在相似条件下的一个标准形,在代数理论及其工程应用中都具有十分重要的意义．针对具有重特征值的矩阵,提出了一种运用奇异值分解方法计算它的特征矢量及若当形的算法．大量数值例子的计算结果表明,该算法在求解具有重特征值的矩阵的特征矢量及若当形上效果良好,优于商用软件MATLAB和MATHEMATICA．     

Wavelet transform associated with linear canonical Hankel transform

The main goal of this paper is to study about the continuous as well as discrete wavelet transform in terms of linear canonical Hankel transform (LCH‐transform) and discuss some of its basic properties. Parseval's relation and reconstruction formula of continuous linear canonical Hankel wavelet transform (CLCH‐wavelet transform) is obtained. Moreover, semidiscrete and discrete LCH‐wavelet transform are also discussed.     

Generalized prolate spheroidal wave functions for offset linear canonical transform in Clifford analysis

Prolate spheroidal wave functions (PSWFs) possess many remarkable properties. They are orthogonal basis of both square integrable space of finite interval and the Paley–Wiener space of bandlimited functions on the real line. No other system of classical orthogonal functions is known to obey this unique property. This raises the question of whether they possess these properties in Clifford analysis. The aim of the article is to answer this question and extend the results to more flexible integral transforms, such as offset linear canonical transform. We also illustrate how to use the generalized Clifford PSWFs (for offset Clifford linear canonical transform) we derive to analyze the energy preservation problems. Clifford PSWFs is new in literature and has some consequences that are now under investigation. Copyright © 2012 John Wiley & Sons, Ltd.     

Herglotz's theorem and quaternion series of positive term

The present paper first introduces the notion of quaternion infinite series of positive term and establishes its several tests. Next, we give the definitions of the positive‐definite quaternion sequence and the positive semi‐definite quaternion function, and we extend the classical Herglotz's theorem to the quaternion linear canonical transform setting. Then we investigate the properties of the two‐sided quaternion linear canonical transform, such as time shift characteristics and differential characteristics. Finally, we derive its several basic properties of the quaternion linear canonical transform of a probability measure, in particular, and establish the Bochner–Minlos theorem. Copyright © 2016 John Wiley & Sons, Ltd.     

Quaternion Fourier and linear canonical inversion theorems

The quaternion Fourier transform (QFT) is one of the key tools in studying color image processing. Indeed, a deep understanding of the QFT has created the color images to be transformed as whole, rather than as color separated component. In addition, understanding the QFT paves the way for understanding other integral transform, such as the quaternion fractional Fourier transform, quaternion linear canonical transform, and quaternion Wigner–Ville distribution. The aim of this paper is twofold: first to provide some of the theoretical background regarding the quaternion bound variation function. We then apply it to derive the quaternion Fourier and linear canonical inversion formulas. Secondly, to provide some in tuition for how the quaternion Fourier and linear canonical inversion theorems work on the absolutely integrable function space. Copyright © 2016 John Wiley & Sons, Ltd.     

����ά��������ģ�͵�PGFR����ɸѡ

In this paper, we consider the ultra-high dimensional partially linear model, where the dimensionality p of linear component is much larger than the sample size n, and p can be as large as an exponential of the sample size n. Firstly, we transform the ultra-high dimensional partially linear model into the ultra-high dimensional linear model based the profile technique used in the semiparametric regression. Secondly, in order to finish the variable screening for high-dimensional linear component, we propose a variable screening method called as the profile greedy forward regression (PGFR) by combining the greedy algorithm with the forward regression (FR) method. The proposed PGFR method not only considers the correlation between the covariates, but also identifies all relevant predictors consistently and possesses the screening consistency property under the some regularity conditions. We further propose the BIC criterion to determine whether the selected model contains the true model with probability tending to one. Finally, some simulation studies and a real application are conducted to examine the finite sample performance of the proposed PGFR procedure.     

Generalized principal pivot transforms, complementarity theory and their applications in stochastic games

In this article, we revisit the concept of principal pivot transform and its generalization in the context of vertical linear complementarity problem. We study solution set and solution rays of a vertical linear complementarity problem. Finally we present an application of generalized principal pivot transform in game theory.