Solution of arbitrarily dimensional matrix equation in computational electromagnetics by fast lifting wavelet‐like transform

A new wavelet matrix transform (WMT), operated by lifting wavelet‐like transform (LWLT), is applied to the solution of matrix equations in computational electromagnetics. The method can speedup the WMT without allocating auxiliary memory for transform matrices and can be implemented with the absence of the fast Fourier transform. Furthermore, to handle the matrix equation of arbitrarily dimension, a new in‐space preprocessing technique based on LWLT is constructed to eliminate the limitation in matrix dimension. Complexity analysis and numerical simulation show the superiority of the proposed algorithm in saving CPU time. Numerical simulations for scattering analysis of differently shaped objects are considered to validate the effectiveness of the proposed method. In particular, due to its generality, the proposed preprocessing technique can be extended to other engineering areas and therefore can pave a broad way for the application of the WMT. Copyright © 2009 John Wiley & Sons, Ltd.     

基于分割模板运动预估的相关跟踪算法

为了对常规相关匹配算法实时性能进行提升，提出一种基于分割模板运动预估的相关跟踪算法。采用最小二乘法全区间等距拟合目标运动轨迹，计算出目标当前预估点；将模板图像按块运动估计算法要求分割成宏块；按菱形搜索法在预估点周围区域进行搜索，得到每个宏块的最佳运动矢量；取匹配度最佳的运动矢量对应点为模板的粗匹配点；判断该点所在宏块与搜索区域相对位置关系，决定是否进行精匹配结束搜索，或是按梯度方向建立新的搜索区域。目标跟踪实验证明，该方法比基于全搜索的归一化积相关( NProd)算法其计算时间缩短到3.31倍。     

Hybrid membranes based on SiO2/polyether-b-polyamide: Morphology and applications

Hybrid materials were prepared incorporating silica networks by the sol–gel process into the poly(amide-b-polyether) block copolymer PEBAX®. PEBAX®/silica hybrids were characterized by transmission electron microscopy, atomic force microscopy, differential scanning calorimetry, and X-ray diffraction. The pervaporation of phenol from dilute aqueous solutions through hybrid membranes was investigated. Films prepared with lower silica contents showed better dispersed inorganic networks and were more selective in the pervaporation of phenol/water solutions. Films prepared with higher silica contents had a clear phase-separated morphology with lower performance in pervaporation. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 178–185, 2001     

Preparation of amphiphilic PS-b-PMAA diblock copolymer by means of atom transfer radical polymerization

Amphiphilic diblock copolymers of polystyrene-b-poly(methacrylic acid) were synthesized by means of atom transfer radical polymerization. First, the polystyrene with a bromine atom at the chain end (PS-Br) was prepared using styrene as the monomer, 1-bromoethyl benzene as the initiator, and CuCl/2,2′-bipyridyl (bpy) as the catalyst ([1-bromoethyl benzene]/[CuCl]/[bpy] = 1:1:3). The polymerization was well controlled. Second, the diblock copolymer of polystyrene-b-poly(tert-butyl methacrylate) was synthesized also by atom transfer radical polymerization using PS-Br as the macro-initiator, CuCl/bpy as the catalyst, and tert-butyl methacrylate (tBMA) as the monomer. Finally, the amphiphilic diblock copolymer, PS-b-PMAA, was obtained by hydrolysis of PS-b-PtBMA under the acid condition. The molecular weight and the structure of aforementioned copolymers were characterized with gel permeation chromatography, infrared, and nuclear magnetic resonance. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 2381–2386, 2001     

易于硬件实现的无链表小波零树编码算法

提出了一种低存储量、高压缩性能的基于快速提升小波变换的无链表是小零树编码算法（LMZC）。该算法采用了最小零树结构以及一种不同于LZC算法的扫描顺序和标志衅表示。实验结果表明LMZC在性能上比LZC高约0.5dB以上，和SPIHT算法比具有相同的压缩性能但更易于硬件实现。     

Relaxational dielectric anomaly in the ferroelectric phase of K2ZnCl4

The temperature dependence of dielectric constant of K₂ZnCl₄ was measured at 10, 20, 40 and 100 kHz in the temperature range between 120 and 250 K. A relaxational dielectric anomaly was observed near 210 K for the first time. It is ascribed to domain wall pinning induced by ferroelastic micro-domains which begin to form around 200 K and behave as defects. The dielectric anomaly disappeared after several thermal cycles of heating and cooling. This may be due to the remnant ferroelastic matrix in the ferroelectric phase.     

视频压缩芯片的应用及低速率图像传输的实现

本文作者介绍了以AD公司的高性能视频压缩芯片ADV601LC为核心的一个低数码率频传输系统.该芯片优良的压缩性能使低数码率视频传输得以实现.     

张家港电厂干煤棚大跨度屋面网架安装

本文主要就本网架工程在施工中遇到的一些大跨度问题及分条分块整体吊装难题作一简要介绍。     

基于小波网络的时间序列预报及其应用

对关键特征参数的准确预报是实现故障预报的重要环节 。本文提出了基于小波网络的非线性时间序列预报模型，探讨了非线性序列预报在故障预报中的应用。从函数逼近角度给出了这种模型的理论基础，给出了小波网络的学习算法，最后给出在空间推进系统上的应用实例。     

基于小波理论的弧焊机器人激光检测系统

研制了一套弧焊机器人激光检测系统，根据激光检测图象的特点，运用小波理论建立了梯形边缘分析模型，并分析了此模型的一些性质，将其成功地运用在激光检测的实时图象处理当中，实验证明，此方法无论是检测时间还是适应性，可靠性都优于传统的LOG方法，有较大的实用价值。