Bayesian regression filters and the issue of priors

We propose a Bayesian framework for regression problems, which covers areas usually dealt with by function approximation. An online learning algorithm is derived which solves regression problems with a Kalman filter. Its solution always improves with increasing model complexity, without the risk of over-fitting. In the infinite dimension limit it approaches the true Bayesian posterior. The issues of prior selection and over-fitting are also discussed, showing that some of the commonly held beliefs are misleading. The practical implementation is summarised. Simulations using 13 popular publicly available data sets are used to demonstrate the method and highlight important issues concerning the choice of priors.     

Vibrations and buckling of composite orthotropic cylindrical shells with nonuniform axial loads

The vibrational response of orthotropic composite cylindrical shells, subjected to circumferentially nonuniform axial loads, is investigated based on Flügge-type field equations. The use of a complex finite Fourier transform provides a simple method for handling any arbitrary nonuniform load but introduces modal coupling between the transformed equations. For simply supported boundaries (conditions SS3) the determination of the critical buckling load reduces to finding the eigenvalues of a finite matrix. Two different nonuniform loads are considered, having forms proportional to (1+2cos θ) and (θ*−θ), where is the Heaviside function, θ is the circumferential coordinate and aθ* is the width of an axial strip of the shell of radius a. Computed results indicate the sensitivity of the critical buckling loads and free vibrational frequency to the type of nonuniform load and the material lay-ups of the cylinders.     

局、矿两级运销计算机管理系统

在原有销售系统的基础上，提出了包括储、装、运、销４个环节局矿两级的计算机管理系统，介绍了该系统的功能以及实施的步骤。     

Deriving Reference Decisions

To solve a statistical decision problem from a Bayesian viewpoint, the decision maker must specify a probability distribution on the parameter space, his prior distribution. In order to analyze the influence of this prior distribution on the solution of the problem, Bernardo (1981) proposed to compare the results with those that one would obtain by using that prior distribution which maximizes the useful experimental information, thus introducing the concept of reference decision. This definition is too involved for most of the problems usually found in practice. Here we analyze situations in which it is possible to simplify the definition of the reference decision, and we provide conditions guaranteeing the existence of such decisions.     

Estimation of complicated distributions using B-spline functions

The distributions of some of random variables are quite complicated and difficult to determine using ordinary statistical models. A method is presented in this paper which gives satisfactory estimation of the complicated distribution of a continuous random variable. There are two key steps in the method: one being that the probability density function (p.d.f.) of a random variable is approximated by a linear combination of B-splines and the other being that the best model is determined by entropy analysis. Extensive numerical experiments have made it clear that the proposed method is useful to determine the p.d.f. directly from a set of sample points without using any prior knowledge of the distribution form.     

结合EMD和加权Mel倒谱的语音共振峰提取算法

提出了一种利用经验模态分解（Empirical Mode Decomposition,EMD）和加权Mel倒谱（Weighted Mel-Cepstrum coefficients,WMCEP）提取语音信号共振峰的算法。对语音信号进行EMD分解,找出含有共振峰的固有模态函数（Intrinsic Mode Function,IMF）,并将其重构得到一个新的重构语音信号。对重构语音信号进行加权Mel倒谱分析,获得包含频谱主要成分的加权Mel倒谱系数;利用离散余弦平滑算法,从加权Mel倒谱系数获得谱包络,并从谱包络的峰值位置获得候选共振峰;根据共振峰的连续性约束条件和频率范围,从候选共振峰筛选得到共振峰的估计值。实验结果表明,该算法比单独使用WMCEP提取的共振峰误差更小,而且在信噪比小于20 dB时仍然能够准确提取出共振峰。     

基于凸差规划的不完整数据填充聚类

为了提升聚类性能,文中提出基于凸差规划(DCP)的不完整数据填充聚类算法.采用DCP对核模糊C均值目标进行凸差化改造,实现DCP聚类和数据缺失项填充的交替优化过程,从理论上证明交替优化的收敛性.在UCI数据集上的实验验证文中算法在缺失数据填充和聚类上的优势.     

基于DC规划的鲁棒模糊核聚类算法

对以径向基核函数和欧拉核函数为代表的鲁棒模糊核聚类算法进行非凸优化,以改善聚类算法目标函数非凸导致的局部解问题.采用凸差规划(DCP)将目标函数转化为2个凸函数之差的形式,减缓局部解的不良性,提高聚类性能.采用凸差算法(DCA)优化求解DCP问题,能快速搜索到相对更优的解,并保持聚类的鲁棒性.在UCI数据集上的实验验证基于DCP的鲁棒模糊核聚类算法对大规模数据集表现出相对更优的聚类性能.     

Word2000中鼠标的妙用十则

介绍Microsoft Word2000中鼠标指标指定“选定区”等10则妙用。     

一种基于多频带PSWFs组合的CUWB自适应脉冲波形设计

本文简述了认知超宽带(CUWB)系统的工作原理,并从自适应频谱环境和兼容FCC频谱模板的角度出发,建立了基于频谱感知来动态构建CUWB系统自适应辐射掩蔽的机制。然后,利用PSWFs函数的特性,提出了一种基于多频带的回转椭球波函数(PSWFs)基的加权线性组合来设计CUWB自适应脉冲波形的算法。仿真结果表明,该算法所产生的脉冲波形不仅能满足CUWB系统频谱模板的要求,而且能自适应模板的动态变化。