Thermoelastic evaluation of composite laminates using digital imaging processing

The study of the variation of the curvature of non-symmetric composite laminates with temperature provides a measure of the magnitude of the thermal stresses and the mechanical behavior of the material with temperature. In the present work, an experimental method based on the pioneer use of a digital camera and image processing method is proposed to perform such measurements. Taking advantage of the method and by comparing experimental and CLT, extended-CLT and FEM simulation results, an evaluation of the residual stresses is described and an approach providing more precise determination of the residual thermal stresses in non-symmetric laminates is proposed.     

强力输送带接头识别算法

针对现有的强力输送带故障实时检测方法存在故障定位困难的问题,以接头为基准参考点,提出了一种基于图像处理技术的强力输送带接头识别算法。该算法根据接头点的特征,把接头点用一个数值表示出来,并根据这个数值,以一种简单的方式区分出上、下接头点;然后根据接头的特征,并通过修改最长公共子序列算法的匹配方式,对接头进行识别。实际应用表明,该算法精度高、速度快,可有效识别强力输送带的接头,满足了强力输送带故障检测中接头定位的要求。     

The preparation of coupled WO3/TiO2 photocatalyst by ball milling

The coupled photocatalyst WO₃/TiO₂ is prepared by ball milling by doping WO₃ into TiO₂ and using H₂O solution as disperser. The coupled photocatalyst WO₃/TiO₂ is characterized by UV–VIS diffuse reflection spectrum, X-ray photoelectron spectroscopy (XPS), X-ray powder diffraction (XRD) and Transmission electron microscopy (TEM). The results show that the optimum percentage of WO₃ doped is 3% and that the photocatalytic activity of the coupled WO₃/TiO₂ photocatalyst is much higher than that of TiO₂ and WO₃–TiO₂ with no ball milling. Compared with TiO₂, the photoexcited wavelength range of the WO₃/TiO₂ photocatalyst red-shifts about 50 nm, and the light absorption intensity is also improved. The crystal phase of TiO₂ is not changed and new crystal phases are not found during the process of ball milling. WO₃ and TiO₂ coupled highly, forming the WO₃/TiO₂ photocatalyst. The increased photocatalytic activity of the coupled photocatalyst may be attributed to the enhance charge separation efficiency and the extend wavelength range of photoexcitation.     

级联No序列的三项式特性研究

利用有限域GF(2n)到其子域GF(2m)上的迹函数及其性质,研究一类非线性扩频序列的密码学性质,即级联No序列的三项式特性。给出级联No序列的三项生成多项式的形式,将级联No序列三项式特性的结论应用到二元No序列中,解决了二元No序列的三项式特性问题。分析结果表明,级联No序列不仅具有三项式对,而且具有正则三项式对。     

基于PSO的负反馈电路参数自适应优化及仿真分析

采用粒子群优化算法,以电压增益、共模抑制比、输入电阻平方根的三者乘积对输出电阻的比作为适应度函数,对差分 共射两级直接耦合电压串联负反馈放大电路中的电阻做自适应优化。结果显示,只要对电路交流指标加以约束,适应度函数值总会减小。当分别对增大电压增益和减小输出电阻进行限制后,电压增益总是尽量小,输出电阻总是尽量大,以使适应度函数在给定约束下取得最大。经EWB软件对优化参数仿真,结果满足线性放大要求。同时说明了可以调整适应度函数形式,找到最佳电路参数,以满足工程上对放大器指标的不同需求。     

Global Avalanche Characteristics of Boolean Functions by Concatenation

In order to measure the correlation propeties of two Boolean functions,the global avalanche characteristics of Boolean functions constructed by concatenation are discussed,i.e.,f_1‖f_2and f_1‖f_2‖f_3‖f_4.Firstly,for the function f = f_1‖f_2,the cross-correlation function of f_1,f_2 in the special condition are studied.In this case,f,f_1,f_2 must be in desired form.By computing their sum-of-squares indicators,the crosscorrelation function between f_1,f_2 is obtained.Secondly,for the function g = f_1‖f_2‖f_3‖f_4,by analyzing the relation among their auto-correlation functions,their sum-of-squares indicators are investigated.Based on them,the sum-of-squares indicators of functions obtained by Canteaut et al.are investigated.The results show that the correlation property of g is good when the correlation properties of Boolean functions f_1,f_2,f_3,f_4 are good.     

基于软件的环境量化模型

在一些特殊领域中需要建立一定的实验环境对软件性能进行测试,因此实验环境与实际环境之间的近似程度对软件的性能起到关键作用。为建立环境之间的近似度量,在进程代数理论基础上,根据软件与环境的交互程度,利用拓扑度量和论域理论中的偏序关系,建立实验环境之间近似程度的量化模型。根据软件与环境之间的部分交互,建立实验环境之间近似程度的度量模型。通过实例对度量模型进行说明,并证明度量模型的代数性质。     

非盲图像复原综述

作为目前图像处理领域的研究重点,图像复原可移除图像中的模糊与噪声,具有重要的理论价值和广阔的应用前景。为使图像复原的研究被人们所了解,该文首先对图像复原做了简单的描述,接着介绍了近年来出现的一些非盲图像复原算法,包括基于总变分模型的算法、基于Bregman迭代的算法和基于稀疏表示的算法等,最后基于对现有算法的了解与分析,总结了图像复原研究的难点与趋势。     

基于自适应控制的数学学习系统的设计与实现

数学知识的学习过程是受教师、教材、环境和学生等内外多种因素影响的复杂系统。基于自适应学习和自适应控制理论,该文设计和实现了数学知识自适应学习系统。这对于实现数学知识学习的个性化和智能化,乃至学习效果的提高都有一定的理论和实践指导意义。