双反对称矩阵反问题解存在的条件

112 数值计算与计算机应用2002年51.问题的提出矩阵反问题及逆特征值问题在工程中应用广泛,关于它们的     

Minimum norm output feedback design under specified eigenvalue areas

Starting from a new parametric expression for the state feedback controller of a linear, time-invariant system a procedure is derived which reduces the design of output feedback controllers to an unconstrained optimization problem where all free parameters, both the closed-loop eigenvalues and the invariant parameter vectors, are used for its numerical solution by a gradient-based search technique. Thus minimal norm output feedback controllers can be designed that place the closed-loop eigenvalues within specified regions of the eigenvalue plane.     

Performance Analysis of Compressed Sensing Given Insufficient Random Measurements

Most of the literature on compressed sensing has not paid enough attention to scenarios in which the number of acquired measurements is insufficient to satisfy minimal exact reconstruction requirements. In practice, encountering such scenarios is highly likely, either intentionally or unintentionally, that is, due to high sensing cost or to the lack of knowledge of signal properties. We analyze signal reconstruction performance in this setting. The main result is an expression of the reconstruction error as a function of the number of acquired measurements.     

非对称网络单向时延的最小范数估计

通信组网成为近年来的发展趋势,而单向时延（One-way delay）则是衡量通信组网服务质量的一个重要指标,因此对它的估计是一项非常重要的工作。往返时延（RTT,Round TripTime）通常被用作一种估计方法,但是这种对半分的方法并不能精确估计单向时延。该文给出了在不依赖外部时钟同步的情况下,利用Windows平台下提供的微秒级高精度性能计数器构建实验模型,利用最小范数估计法获得单向时延,它具有高精度、可在线测量和可适用于非对称通信网络的优点。     

基于L2范数的相关叠加去噪方法

本文在研究传统相干算法的基础上,提出了一种利用邻域相关性的加权叠加压制地震随机噪声的方法,即利用L2范数估计邻域间的相似度,并以邻域间欧氏距离的高斯函数作为计算加权系数的策略,实现邻域点的相关叠加,从区域识别信号到局部保真压噪。模型及实际资料的处理计算结果表明:该方法能够有效消除随机干扰,且信号的保真度高,是低信噪比条件下资料处理的可行方法。     

局部平面波模型约束下的迭代加权最小二乘反演三维地震数据规则化

数据规则化是地震数据处理中一项十分重要的内容,本文提出一种基于迭代加权最小二乘反演的数据规则化方法。该方法的思路是:在Cauchy模意义下引入与模型有关的加权算子对数据拟合剩余量进行加权,可有效避免野值对插值结果的影响;采用平面波解构滤波器估计的局部倾角信息作为约束条件,不仅可保证反演过程稳定,而且能对假频数据有效插值;通过预条件共轭梯度法迭代求解,提高收敛速度;采用分时间切片并行化处理,可进一步提高三维地震数据规则化处理的效率。理论模型和实际地震数据的插值试验结果验证,本文提出的地震数据规则化处理方法速度快,效果好,具有较高实用价值和广泛应用前景。     

基于极速学习的粗糙RBF神经网络

提出了一种用于训练粗糙RBF神经网络(rough RBF neural networks,R-RBF)的极速学习机(extreme learning machine,ELM)方法,通过引入矩阵的Moore-Penrose逆,将传统的迭代学习方法转换为一种求线性方程的极小范数最小二乘解的方法.实验证明,在训练精度、训练时间上都能够达到非常优越的性能,其泛化精度能够提升50%以上.     

Unsupervised fabric defect segmentation using local patch approximation

In this work, a new method based on local patch approximation is presented to address automated defect segmentation on textile fabrics. The proposed method adopts unsupervised scheme without the need of reference images or any other prior information. Image patch is approximated by dictionary learned from a testing sample in the least squares sense. With the clue of the differentiation in approximation error, abnormal map (each pixel’s anomalous likelihood) can be computed from the patch-level difference. The 2D maximum entropy with neighbourhood considered is applied to segment defective regions from the abnormal map. The experiments on 54 defective samples demonstrate that our method yields a robust and good overall performance with high precision and accepted recall rates.     

一类推广的Brenstien算子及其性质

本文证明了一类推广的Brenstein算子在一定条件下的单调性及收敛性,进而讨论了算子序列的收敛问题。     

Genotype x environment interaction for protein yield in Dutch dairy cattle as quantified by different models

Variance components and breeding values for protein yield were estimated with REML without and with correction for heterogeneity of variances. Three different sire models were applied, which all accounted for genotype x environment (G x E) interaction. The first model included a sire x herd-year-season subclass (HYS) interaction. The second model divided all records in four different types of management groups, based on estimated HYS subclass effect. The third model, the reaction norm model, performed a random linear regression on the estimated HYS effect. For comparison, a standard model that did not take G x E interaction into account was also applied. Data consisted of 102,899 305-d first-lactation protein records of Holstein Friesians of 1,000 ofthe largest Dutch dairy herds. All animals calved in 1997, 1998, or 1999. Estimated breeding values (EBV) for 2,150 bulls with at least five daughters were calculated. The interaction model detected an interaction variance of 2.5% of the phenotypic variance. The EBV showed a correlation of 1.00 with those of the standard model without interaction. The model with the division in groups showed correlations between groups ranging from 0.73 to 0.86. The EBV showed correlations from 0.84 to 0.91 with the EBV of the standard model. The reaction norm model calculated EBV that had a correlation of 1.00 with the EBV of the standard model. The reaction norm model was not able to detect significant variance of the slope for the protein data corrected for heterogeneity of variances.