用于含过程调用DO循环的循环嵌入方法

循环是程序中蕴含并行性最为丰富的一种结构，因此成为并行化编译最主要的对象．但循环内的过程调用严重妨碍了循环的数据相关性分析，使得循环语句潜在的大量并行性得不到开发．本文提出的循环嵌入方法使部分含过程调用循环语句的并行化成为可能，对部分用其它过程间分析技术也能开发其并行性的这一类循环语句采用循环嵌入方法，并行化开销低，并且分析更精确．采用循环嵌入方法还可降低程序由于多次过程调用带来的调度开销．这一方法在作者开发的自动并行化编译系统AFT（automaticPortrantransformer）中得到了实现，对Spec92测试程序包的试验结果表明了本文提出的方法是行之有效的．

有限群的弱Π嵌入子群（英文）

令G是1个有限群,且H是G的1个子群.子群H称为在G中是弱Π嵌入的,如果存在G的1个子群对(T,S)使得|G:HT|是某个素数的方幂,且(H∩T)/H_G≤S/H_G,其中T是G的1个包含H_G的拟正规子群且S/H_G≤H/H_G是G/H_G的1个满足Π性质的子群.这里利用弱Π嵌入子群研究有限群的结构.特别地,得到了子群是超循环嵌入的新判断准则.

基于R树的高维孤立点检测算法研究与实现

高维孤立点检测算法已经在移动互联网、金融欺诈检测、网络入侵检测、生态系统失调、天气预报等风险控制领域得到了广泛的应用。基于距离的孤立点检测思想,结合高维数据特点,参考R树的相关操作算法,设计实现基于R树的高维孤立点检测算法。算法在剪枝策略,排序方法上较以前同种算法更有优势。在真实的数据集上的实验结果表明,该算法能在高维条件下有效地检测出孤立点,并且算法的效率高于嵌入循环算法。

Performance analysis model for real-time Ethernet-based computer numerical control system

In order to optimize the embedded system implementation for Ethernet-based computer numerical control （CNC） system, it is very necessary to establish the performance analysis model and further adopt the codesign method from the control, communication and computing perspectives. On the basis of analyzing real-time Ethemet, system architecture, time characteristic parameters of control-loop ere, a performance analysis model for real-time Ethemet-based CNC system was proposed, which is able to include the timing effects caused by the implementation platform in the simulation. The key for establishing the model is accomplished by designing the error analysis module and the controller nodes. Under the restraint of CPU resource and communication bandwidth, the experiment with a case study was conducted, and the results show that if the deadline miss ratio of data packets is 0.2%, then the percentage error is 1.105%. The proposed model can be used at several stages of CNC system development.

On embedding infinite cyclic covers in compact 3-manifolds

We show that there are knots whose infinite cyclic covers do not embed in any compact 3-manifold,answering a question of Jiang et al.(2006).