Reversible computing and cellular automata—A survey

Reversible computing is a paradigm where computing models are defined so that they reflect physical reversibility, one of the fundamental microscopic physical property of Nature. In this survey/tutorial paper, we discuss how computation can be carried out in a reversible system, how a universal reversible computer can be constructed by reversible logic elements, and how such logic elements are related to reversible physical phenomena. We shall see that, in reversible systems, computation can often be carried out in a very different manner from conventional (i.e., irreversible) computing systems, and even very simple reversible systems or logic elements have computation- or logical-universality. We discuss these problems based on reversible logic elements/circuits, reversible Turing machines, reversible cellular automata, and some other related models of reversible computing.     

Optimal infinite scheduling for multi-priced timed automata

This paper is concerned with the derivation of infinite schedules for timed automata that are in some sense optimal. To cover a wide class of optimality criteria we start out by introducing an extension of the (priced) timed automata model that includes both costs and rewards as separate modelling features. A precise definition is then given of what constitutes optimal infinite behaviours for this class of models. We subsequently show that the derivation of optimal non-terminating schedules for such double-priced timed automata is computable. This is done by a reduction of the problem to the determination of optimal mean-cycles in finite graphs with weighted edges. This reduction is obtained by introducing the so-called corner-point abstraction, a powerful abstraction technique of which we show that it preserves optimal schedules. This work has been mostly done while visiting CISS at Aalborg University in Denmark and has been supported by CISS and by ACI Cortos, a program of the French Ministry of Research.     

采用动态邻域扩展算法的非一致CA低功耗确定TPG

针对确定内建自测试向量发生器设计中常存在着对冗余向量依赖,导致测试应用时间增长,并产生额外的测试功耗等问题,提出一种新的低功耗确定测试向量发生器的综合算法.该向量发生器采用非一致细胞自动机的结构实现,利用基于模拟退火的动态邻域扩展算法寻找优化的细胞自动机的拓扑连接关系.对标准组合电路仿真实验的结果表明,所综合出的向量发生器可有效地产生给定的低功耗确定向量集,并且不影响原有的故障覆盖率和测试时间.     

基于无秩树自动机的信息抽取技术研究

针对目前基于网页结构的信息抽取方法的缺陷,提出了一种基于无秩树自动机的信息抽取技术,其核心思想是通过将结构化(半结构化)文档转换成无秩树,然后利用(k,l)-contextual树构造样本自动机,依据树自动机接收和拒绝状态来对网页进行数据的抽取.该方法充分利用结构,依托树自动机将传统的以单一结构途径的信息抽取方法与文法推理原则相结合,得到信息抽取规则.实验结果表明,该方法与同类抽取方法相比在准确率、召回率以及抽取所需时间上均有所提高.     

Active XML文档安全重写判定算法

研究了AXML文档安全重写判定问题,即判定给定AXML文档通过触发其包含的服务调用生成的文档集合是否能够全部重写为符合目标模式的文档实例.基于树自动机理论,定义了用于抽象AXML文档的树自动机--ATA机(AXML treeautomata),ATA机等价于给定AXML文档通过触发其包含的服务调用所能生成的文档集合.基于ATA机,提出一个AXML文档安全重写判定算法,表明了该算法的正确性及有效性.     

Symbolic Algorithmic Analysis of Rectangular Hybrid Systems

This paper investigates symbolic algorithmic analysis of rectangular hybrid systems.To deal with the symbolic reachability problem,a restricted constraint system called hybrid zone is formalized for the representation and manipulation of rectangular automata state-spaces.Hybrid zones are proved to be closed over symbolic reachability operations of rectangular hybrid systems.They are also applied to model-checking procedures for verifying some important classes of timed computation tree logic formulas.To ...     

基于元胞自动机的股票价格宏观变化的研究

为了研究股票价格在宏观上的变化趋势以及产生这些变化的主要因素.提出了一种新的基于元胞自动机的模型分析股票价格宏观变化,构建了新的股票价格变化规则以及新的股票交易量的变化模型,假设了两大类影响股票价格宏观变化趋势的肉素,同时也细化了股票交易量的函数.模拟了当影响因素都利好,影响因素都利空以及影响因素利好利空交替出现的情况下,股票价格在宏观上的变化情况.仿真结果在一定程度上模拟了股票价格的宏观变化情况和股票价格变化的波动壤集性,说明了假设的两大类因素的合理性以及演化模型的正确性.     

一种基于受限网络的移动对象索引

为了有效地支持城市交通网络中移动对象的过去、现在和将来的轨迹查询,在基于模拟预测的位置表示模型基础上,提出了一种两层R树加上一个表结构的复合索引结构AUC(Adaptive Unit Compounding).根据城市交通网的特征,采用了一种带有环形交叉口的元胞自动机模型模拟移动对象的将来轨迹,并用线性回归和圆弧曲线拟合分别得到对象在规则路段和交叉口的轨迹预测方程;根据移动对象的运动特性,采用了一种新的自适应单元(AU)作为索引结构的基本单位.实验表明,AUC索引的查询和更新性能都要优于TPR树和TB树.     

时间自动机的LTL性质模型检测研究

为了增强模型检测工具的检测能力,拓宽模型检测技术的应用范围,对基于时间自动机的LTL性质模型检测进行了研究,对自动机的状态空间的存储方式和状态空间的展开过程进行了分析,讨论了LTL性质模型检测工具的检测流程和检测算法的实现策略对工具检测性能的影响,针对制约模型工具的检测能力和检测效率的因素,采取了一些相应的优化改进策略.采用了BDD(二叉决策图)共享存储技术和位编码压缩存储,较有效地减小了空间消耗,缓解了模型检测中状态爆炸引起的内存空间不足问题.与DTSpin等著名的模型检测工具进行了实验比较,取得了较好的实验结果.     

胚胎型仿生电路中具有自修复性能的存储器设计

胚胎型仿生电路是一种芯片级容错数字电路,其工作机制为汲取生物体生长过程的灵感从而使得数字系统具有自主容错能力。该电路是由二维电子细胞阵列组成,文中分析了这种数字电路的结构和容错机制,讨论了细胞的主要组成部件的设计,并基于海明码(Hamming Code)为细胞中的存储器设计了一种具有自检测和自修复能力的结构。最后,以4×4乘法器为应用实例,通过仿真实验验证了细胞中存储器的自诊断、自修复能力和该仿生电路的自修复能力。