C指针使用中的几个问题

本文给出C指针使用中的四个常见问题,详细分析了其产生原因,并指出如何避免这些问题.     

进位保留阵列乘法器的一种内建自测试

对进位保留阵列乘法器提出了一种内建自测试方案。设计实现了采用累加器生成测试序列和压缩响应,并提出了一种改进的测试向量生成方法。分析与实验结果表明,该方案能实现非冗余固定型故障的完全覆盖。由于乘法器在数据通路中常伴有累加器,该方案通过对已有累加器的复用,作为测试序列生成和响应压缩,减少了硬件占用和系统性能占用,同时具有测试向量少、故障覆盖率高的特点。     

印制电路板自动测试系统的设计与应用研究

采用ＣＭＯＳ开关阵列对印制电路板测试系统的组成、测试原理与软件编程技术进行了自动测试的设计与应用研究。结果表明，该系统可有效提高印制电路板的测试水平。在保障产品质量的同时，大幅度提高了生产效率，实现了预期的系统性能与技术指标的要求。     

Identifying Dispersion Effects in Robust Design Experiments—Issues and Improvements

The two experimental methods most commonly used for reducing the effect of noise factors on a response of interest Y aim either to estimate a model of the variability (V(Y), or an associated function), that is transmitted by the noise factors, or to estimate a model of the ratio between the response (Y) and all the control and noise factors involved therein. Both methods aim to determine which control factor conditions minimise the noise factors' effect on the response of interest, and a series of analytical guidelines are established to reach this end. Product array designs allow robustness problems to be solved in both ways, but require a large number of experiments. Thus, practitioners tend to choose more economical designs that only allow them to model the surface response for Y. The general assumption is that both methods would lead to similar conclusions. In this article we present a case that utilises a design based on a product design and for which the conclusions yielded by the two analytical methods are quite different. This example casts doubt on the guidelines that experimental practice follows when using either of the two methods. Based on this example, we show the causes behind these discrepancies and we propose a number of guidelines to help researchers in the design and interpretation of robustness problems when using either of the two methods.     

基于BP人工神经网络的磨料水射流切割深度模型

在已知的磨料水射流切割混凝土实验数据的基础上,应用BP人工神经网络理论,并且借助MATLAB神经网络工具箱,建立磨料水射流切割深度模型.模型中包括的射流参数有射流压力、靶距、磨料粒径、磨料流量、磨料喷嘴直径、磨料喷嘴长度及横移速度.通过模型预测结果与实验结果的比较,表明模型具有一定的精度.     

阵列通道误差校正算法及DSP实现

阵列通道幅相不一致性严重影响测向性能。基于辅助源的相关校正理论,研究了通过在天线馈电口输入辅助信号,再对信号求相关来实现对阵列通道不一致性的校正;并分析了基于多基线数字干涉仪体制的测向原理,利用五元圆形天线阵列估计出了地面目标的到达角。此外,还讨论了所有算法的DSP实现,计算机模拟证实了方法的有效性。     

免疫信息系统的数据安全与应用

随着社会的进步,居民生活水平的不断提高,疾病防护与儿童免疫全面信息化管理已经成为社会趋势。而对于该系统的数据安全问题就更显得十分重要,本采用双机热备份系统,对数据进行实时备份。     

支持多关键字的P2P搜索研究

传统的P2P系统是基于单特征词搜索的，且不支持语义，存在一定的局限性。提出了可变长数组模型，解决了P2P系统中多特征词搜索的问题；标识符空间的分割，使相同领域的文档在邻近的节点聚集，提高了搜索速度；本体技术的应用，使P2P系统能够理解搜索请求，有利于查全率的提高。     

Some resolvable orthogonal arrays with two symbols

A method of constructing a resolvable orthogonal array (4λk2,2) which can be partitioned into λ orthogonal arrays (4,k 2,1) is proposed. The number of constraints kfor this type of orthogonal array is at most 3λ. When λ=2 or a multiple of 4, an orthogonal array with the maximum number of constraints of 3λ can be constructed. When λ=4n+2(n≧1) an orthogonal array with 2λ+2 constraints can be constructed. When λ is an odd number, orthogonal arrays can be constructed for λ=3,5,7, and 9 with k=4,8,12, and 13 respectively.     

Maximal inequalities for partial sums of independent random vectors with multi dimensional time parameters

We obtain upper and lower bounds on the distribution of the partial sums constructed from a multi-dimensional array of independent random vectors. These bounds include, among others, generalizations of some of the well known classical inequalities such as the converse Kolmogorov and the Skorokhod-Ottaviani maximal inequalities.