基于Agent动态网络的疾病传播模型

提出一个基于Agent动态网络的疾病传播模型,研究疾病在人群中传播扩散的动态过程。在扩展疾病传播的SIR模型基础上,利用不同的个体状态描述各阶段病情。在二维规则网络上,通过增加个体自主移动性构建动态社会网络,并考虑个体异质性和所采取的防护措施对疾病传播的影响。仿真结果表明,该模型较好地反映了动态社会网络和个体适应性行为对疾病传播的影响,并与实际情况基本保持一致。     

Robust object tracking based on adaptive templates matching via the fusion of multiple features

Moving object tracking under complex scenes remains to be a challenging problem because the appearance of a target object can be drastically changed due to several factors, such as occlusions, illumination, pose, scale change and deformation. This study proposes an adaptive multi–feature fusion strategy, in which the target appearance is modeled based on timed motion history image with HSV color histogram features and edge orientation histogram features. The variances based on the similarities between the candidate patches and the target templates are used for adaptively adjusting the weight of each feature. Double templates matching, including online and offline template matching, is adopted to locate the target object in the next frame. Experimental evaluations on challenging sequences demonstrate the accuracy and robustness of the proposed algorithm in comparison with several state-of-the-art algorithms.     

基于时间自动机的Ad hoc网络入侵检测

该文提出一种基于时间自动机分布式合作的入侵检测算法。首先,将整个网络分为子区域,每一区域随机选出簇头担任监视节点,负责本区域的入侵检测。其次,按照路由协议构筑节点正常行为和入侵行为的时间自动机,监视节点收集其邻居节点的行为信息,利用时间自动机分析节点的行为,识别入侵者。该算法不需要事先进行数据训练并能够实时检测入侵行为。最后,通过模拟实验证实了算法的有效性。     

Specification and verification of reactive system behaviour: The Railroad Crossing example

In this paper we present an approach to the specification and verification of reactive systems. The approach uses Timed Statecharts and Real Time Logic for the specification of temporal behaviour, and theorem proving techniques for the verification of safety and utility properties. Formal verification is achieved through the automation of semi-formal (rigorous) proofs using a theorem prover (Proofpower HOL). To illustrate the approach, we use the Railroad Crossing Problem, which has been proposed, along with a set of criteria for assessment, as a benchmark for the comparison of real-time formalisms. We conclude with our assessment of the approach against the proposed criteria.     

A generalized Ufnarovski graph

An important tool for studying standard finitely presented algebras is the Ufnarovski graph. In this paper we extend the use of the Ufnarovski graph to automaton algebras, introducing the generalized Ufnarovski graph. As an application, we show how this construction can be used to test Noetherianity of automaton algebras.     

Product interval automata

We identify a subclass of timed automata called product interval automata and develop its theory. These automata consist of a network of timed agents with the key restriction being that there is just one clock for each agent and the way the clocks are read and reset is determined by the distribution of shared actions across the agents. We show that the resulting automata admit a clean theory in both logical and language theoretic terms. We also show that product interval automata are expressive enough to model the timed behaviour of asynchronous digital circuits.     

基于CA模型的凝固聚类算法

聚类是数据挖掘领域的重要研究内容之一。参考基于元胞自动机距离变换算法模型,构建了基于CA模型的凝固聚类算法,该算法在CA模型演化的过程中,可以产生完整的层次聚类结果,同时对簇间的距离实现了度量,能够处理形状复杂的聚类对象,具有较好的向高维空间的推广能力以及并行计算的特性。最后通过两组聚类数据进行了实证研究,验证了该算法的有效性。     

元胞自动机在水轮机特性数据处理中的应用

给出一种基于元胞自动机的曲线逼近方法,并将这种方法应用于对水轮机的特性数据进行数值逼近。实例计算结果表明,使用基于元胞自动机的曲线逼近方法逼近水轮机的特性数据,所得到的逼近结果具有计算精度高、能够真实反映水轮机特性的特点,可以用于水轮机的控制和优化运行等方面。     

CONTROL OF A PULSED LIQUID-LIQUID EXTRACTION COLUMN BASED ON A MULTILEVEL SYSTEM OF AUTOMATA

This paper presents the real-time application of the learning control theory to the control of a chemical pilot plant: a pulsed liquid-liquid extraction column.

The behaviour of an agitated liquid-liquid extraction column can be related to random mechanisms such as the phenomena of droplets breakage and coalescence. Previous studies on hydrodynamic and mass transfer aspects showed that a pulsed liquid-liquid extraction column had an optimal behaviour for operating conditions close to flooding. These results led to choose the following strategy to control the column in its optimal behaviour zone:

- the measure of the conductivity of the liquid medium below the distributor which gives a good information about flooding, is the controlled variable

-the pulse frequency is the control action.

The learning control algorithm is based on a multilevel system of automata which operates in a random environment. By means of an evaluation unit of the performances of the column which generates either penalty (inaction) or reward on the basis of heuristic rules, the automaton chooses a value of the pulse frequency. This approach is essentially connected to artificial intelligence in so far as human knowledge on the plant is included in these rules.

This algorithm has been implemented on a microcomputer for control purposes. The experimental results presented show the good performances of the approach.     

Synchronization models for multimedia presentation with user participation

This paper addresses the key issue of providingflexible multimedia presentation with user participation and suggests synchronization models that can specify the user participation during the presentation. We study models like the Petrinet-based hypertext model and the object composition Petri nets (OCPN). We suggest adynamic timed Petri nets structure that can model pre-emptions and modifications to the temporal characteristics of the net. This structure can be adopted by the OCPN to facilitate modeling of multimedia synchronization characteristics with dynamic user participation. We show that the suggested enhancements for the dynamic timed Petri nets satisfy all the properties of the Petri net theory. We use the suggested enhancements to model typical scenarios in a multimedia presentation with user inputs.