Shift-full-rank matrices and applications in space-time trellis codes for relay networks with asynchronous cooperative diversity

To achieve full cooperative diversity in a relay network, most of the existing space-time coding schemes require the synchronization between terminals. A family of space-time trellis codes that achieve full cooperative diversity order without the assumption of synchronization has been recently proposed. The family is based on the stack construction by Hammons and El Gamal and its generalizations by Lu and Kumar. It has been shown that the construction of such a family is equivalent to the construction of binary matrices that have full row rank no matter how their rows are shifted, where a row corresponds to a terminal (or transmit antenna) and its length corresponds to the memory size of the trellis code on that terminal. We call such matrices as shift-full-rank (SFR) matrices. A family of SFR matrices has been also constructed, but the memory sizes of the corresponding space-time trellis codes (the number of columns of SFR matrices) grow exponentially in terms of the number of terminals (the number of rows of SFR matrices), which may cause a high decoding complexity when the number of terminals is not small. In this paper, we systematically study and construct SFR matrices of any sizes for any number of terminals. Furthermore, we construct shortest (square) SFR (SSFR) matrices that correspond to space-time trellis codes with the smallest memory sizes and asynchronous full cooperative diversity. We also present some simulation results to illustrate the performances of the space-time trellis codes associated with SFR matrices in asynchronous cooperative communications.     

基于被动测试的web应用测量

提出一种新的基于被动测试的web应用测量方法,以便准确、快速的获取应用特征与状态信息。设计了web应用测量协议WMP,并对基于该协议的测量系统进行了设计与实现。实验表明该系统能够准确快速地对待测的应用协议交互部分进行测量,为应用管理提供丰富有效的信息。     

消防水箱设计中常见错误及改正措施

根据现行消防技术规范的有关规定，结合建筑工程消防监督审核的工作实践，指出了消防水箱设计中常出现的错误并提出了相应的改正措施。     

大气监测仪器的发展及检定中的问题探讨

本文叙述了大气监测仪器的起源发展过程,分析在检定工作中存在的问题,讨论了解决办法。     

论包装与品牌定位

在现代商业社会,包装的价值已经从一个单纯保护商品的功能转化为提升和凸现品牌定位的更高层面上来了.如何有效、科学地利用一个产品的包装色彩、包装造型、包装材料以及包装上面的产品名称、图案、符号、文字等可视元素,成为促进与强化一个品牌定位在客户心目中塑造的重要的营销手段.     

我国矿业权评估管理研究

分析了矿业权评估管理体系和我国矿业权评估现状，提出了促进我国矿业权评估发展的建议。     

一种基于SQL Server视图的数据库安全机制研究

介绍一种基于SQL Server2000视图的数据库安全机制,并给出了具体的实现方法.     

A dual neural network for redundancy resolution of kinematically redundant manipulators subject to joint limits and joint velocity limits

In this paper, a recurrent neural network called the dual neural network is proposed for online redundancy resolution of kinematically redundant manipulators. Physical constraints such as joint limits and joint velocity limits, together with the drift-free criterion as a secondary task, are incorporated into the problem formulation of redundancy resolution. Compared to other recurrent neural networks, the dual neural network is piecewise linear and has much simpler architecture with only one layer of neurons. The dual neural network is shown to be globally (exponentially) convergent to optimal solutions. The dual neural network is simulated to control the PA10 robot manipulator with effectiveness demonstrated.     

感应电动机转子磁场定向的一种自校准算法

介绍感应电动机矢量控制系统中转子磁场定向的一种自校准算法。该算法只需检测电动机的定子电流和转速信号，并由具有严格正实误差传递函数的参数调整算法保证其稳定性和收敛性。数值仿真实验说明了算法的性能。     

新试剂2-(2''''-苯并噻唑偶氮)-1,8-二羟基-3,6-萘二磺酸与钛(Ⅳ)和 CTMAB 形成三元络合物显色反应的研究

在阳离子表面活性剂ＣＴＭＡＢ存在下，２－（２′－苯并噻唑偶氮）－１，８－二羟基－３，６－苯二磺酸与钛（Ⅳ）在ｐＨ３．５～４．５范围内发生高灵敏的显色反应，形成一种蓝色的三元胶束络合物，其最大吸收波长位于６５０ｎｍ，表观摩尔吸光系数ε＝１．２２×１０５·Ｌ·ｃｍ－１。络合物中钛（Ⅳ）与显色剂的组成比为１：２，钛含量在０～８．０μｇ／２５ｍＬ范围内符从比尔定律。间用于铝合金中微量钛的测定，结果满意。