Rijndael加密算法的密钥扩展算法的研究

本文先对Rijndael加密算法的密钥扩展算法进行了简要阐述,之后给出了密钥扩展算法的递归模型并对其进行了分析,最后指出Rijndael加密算法与密钥扩展算法之间的同步特性,并进而阐述了实现加密算法时应用该特性可以节约消耗的时间和空间.     

A Compact Implementation of AES S-Box Using Evolutionary Algorithm

S-Box based on Composite field arithmetic (CFA) technology is optimized by Genetic algorithm (GA) and Cartesian genetic programming (CGP) model for re-ducing the hardware complexity. After using the CFA tech-nique to map Multiplicative inverse (MI) over GF(28) into composite field GF((24)2), the compact MI circuit over GF(24) is selected from 100 evolved circuits, and same design method is applied to the compact multipli-cation circuit over GF(22). Compared with the direct im-plementations, the areas of optimized circuits of MI over GF(24) and multiplication over GF((22)2) are reduced by 66% and 57.69%, respectively. The area reductions for MI over GF(28) and the whole of S-Box are up to 59.23%and 56.14%, separately. In 180nm 1.8V COMS technology, compared to previous works, the S-Box proposed in this paper has the minimum area and minimum power, which are 11.27% and 6.65% smaller than that of the smallest area S-Box, respectively.     

基于GMM聚类的空调机组多未知模态辨识方法研究

智能建筑空调机组故障检测与诊断是保证建筑环境安全、舒适、节能的基本方法.然而,多未知模态辨识仍是其中的关键难点之一.鉴于高斯混合模型(GMM)不受特定概率分布局限,可在区分类别的基础上直接得出数据的统计分布,具有优越的计算性能,且能拟合任意连续分布,本文提出一种基于GMM的空调机组多未知模态辨识方法.仿真试验结果表明,GMM聚类方法在空调机组运行模态辨识中具有较高的准确性与可靠性.