基于描述逻辑的EER模型检测

首先分析基于描述逻辑的ER模型的研究现状,提出基于描述逻辑SHOIN(D)的EER模型,给出描述逻辑SHOIN(D)的语法和语义。然后研究EER模型的SHOIN(D)描述形式,以及如何将EER模型向SHOIN(D)知识库转化。最后给出EER模型可满足性、冗余性判定定理,证明了这些推理问题的正确性,并利用pellet推理机实现了EER模型可满足性和冗余性推理。     

用于安全协议分析的一种新的状态剪枝方法

Strand空间模型是利用图的形式来描述和分析安全协议的。通过对该模型的研究,总结了已有的状态空间简化技术;研究了如何将认证测试理论应用于安全协议分析中,根据认证测试理论我们得出了一个剪枝定理。研究表明该剪枝定理能够大大减少协议分析中的冗余状态,提高了协议分析的效率。     

面向多无人系统的安全协同模型

随着无人系统技术的不断发展,多无人系统的协同控制技术受到了广泛的关注。设计合理的协同模型是多无人系统中的重要研究内容,而已有协同模型在开放的网络环境中存在一定的安全性问题。在分析已有模型的不足的基础上,提出了一种具有安全特性的多无人系统协同模型RCC(Rules Combined Coordination)。RCC模型在协同过程中引入了逻辑规则,提供了终端的合法性认证及通信双方的权限控制,保障了多无人系统的安全性。最后,基于开源机器人系统ROS及RCC模型,搭建了多无人车的协同仿真平台,并在其中设计了导航、避障等实验场景,仿真实验的相关结果验证了RCC模型具有可用性和安全性。     

空间职责分离约束的实施

支持空间特性的RBAC模型描述了多种空间约束,这些空间约束不但表达了位置感知系统中细粒度空间语义,而且给模型增加了空间安全描述能力.能否准确实施空间约束直接影响应用系统功能和开销.本文研究空间职责分离(SSoD)约束的两种实施策略:(1)直接实施(2)间接实施.证明了直接实施是一个NP完全问题,而通过互斥空间角色(MESR)约束间接实施SSoD是有效的.多个MESR约束可以实施同一个SSoD,在比较后发现,当使用最小MESR约束作为实施机制时,能有效避免冗余约束准确实施该SSoD.为获得最小MESR约束本文给出了GEN-MESR算法.     

空间网络数据库中反k最近邻查询算法

在空间网络数据库中,对象的位置和运动被约束在网络中,对象之间的距离不是传统的欧氏距离,而是由网络连通性决定的网络距离,因此,基于欧氏空间的反最近邻查询算法不适用于空间网络数据库.本文对空间网络数据库中的反最近邻查询问题进行了研究.给出网络数据和兴趣点的索引结构及空间网络数据存储模型.给出查询空间修剪定理,并在此基础上,提出空间网络数据库中适用于单、双色反七最近邻查询的RkNN算法.证明了该算法的正确性.最后通过实验对算法进行了验证.     

一种高可靠宇航控制器设计及可靠性评估

将8051、存储器等IP核集成在FPGA内部, 可实现宇航控制器高可靠、小型化的应用需求。但FPGA在空间环境中容易发生单粒子翻转事件(SEU),影响系统正常功能,常采用在FPGA内部进行三模冗余(TMR)设计;针对三模冗余系统无法纠正存储区中发生的SEU故障,提出了一种采用三模冗余架构并对FPGA配置区域进行刷新重载的解决方案,同时采用马尔可夫模型对该设计方案进行了可靠性评估和仿真;结果表明,采用该设计架构的宇航控制器具有较高的可靠性与安全性,可实现飞行器的长期稳定运行。     

基于区域延伸的定性空间表示

在区域连接演算(region connection calculus,RCC)理论基础上给出了区域延伸的形式定义.通过区域延伸,定义了关联空间的概念,进而提出了空间表示的一个模型,在这个模型中给出了空间中物体的空间拓扑关系、距离关系、方向关系以及位置等信息的定性表示.智能体对空间关系的确定是通过区域延伸实现的,模型为智能体在约束空间环境中的行动推理提供了一个新的表示方法.     

基于键合图模型的新型解析冗余关系故障诊断方法研究

研究了通过诊断键合图模型建立系统解忻冗余关系(ARRs)的故障诊断方法.通过在系统键合图中加入虚拟传感器的方法建立系统的诊断键合图,根据诊断键合图模型的因果关系路径构建系统的解析冗余关系和系统故障特征矩阵,并利用系统实际观测特征与故障特征的比较进行系统的故障检测和隔离,通过在双容水箱系统的仿真验证,证明了该方法便捷性和...     

基于OPC通信协议的冗余系统设计

以用于远程控制的对象连接与嵌入(OPC)标准接口为例,研究了在OPC标准接口的基础上,增加冗余通信功能和冗余切换功能。采用两路冗余接口通信和判断冗余接口通信状态的方法,实现了两条冗余通信链路的切换。采用冗余接口通信和冗余切换机制技术,实现了冗余系统的设计,满足了单一故障原则。通过在核电厂仪控系统中的实际应用,冗余的通信链路实现了正常接口通信功能和满足了核电厂对冗余系统的设计要求。研究结果证明了通过该冗余接口通信的方式实现的冗余系统在稳定性和可靠性上满足核电厂设计要求。     

关于离散系统稳定性的一个定理

本文给出了关于离散定常线性系统的稳定性的一个定理。利用数论中的一个定理,证明了系统x(k+1)=Ax(k)渐近稳定的充分必要条件是,当k→∞时,tr[A~k]→0。根据这个定理可以通过A的迹判断离散的定常线性系统的稳定性。     

Digital Connectivity and Extended Well-Composed Sets for Gray Images

In this paper, we propose a new definition of digital connectivity for gray images on a 2D space for arbitrary grid systems. We extend a digital version of the Jordan curve theorem and its converse proved earlier by Rosenfeld for the rectangular grid system. We also extend in two directions the concept of well-composed sets introduced by Lateckiet al.(1995,Comput. Vision Image Understanding61,70–83). First, we extend the definition of well-composed sets from the quadratic grid system to an arbitrary grid system. Then, by using the concept of parameter-dependent connected components introduced by us in a previous work, we allow the pixels in a connected component of a well-composed set to have different gray values so that the connectivity of connected components accommodates a wider meaning.     

星型网络的3-限制边连通性

星型互连网络是并行与分布式处理领域中最流行的互连网络之一,它以n维星图作为拓扑结构。k-限制边连通度是衡量网络的可靠性的参数之一。一般来说,一个网络的k-限制边连通度越大,其连通性就越好。研究了星型互连网络的k限制边连通度;证明了当n≥3时,n维星型互连网络的3-限制连通度为3n－7。     

星网的4-限制边连通度

星网是并行与分布式处理系统中最流行的互连网络之一,它以n维星图作为拓扑结构。k-限制边连通度是衡量网络可靠性的重要参数之一;一般地,网络的k-限制边连通度越大,它的连通性就越好。研究了星网的k-限制边连通度,证明了当n≥4时,n维星网的4-限制连通度为4n－10。     

矩形中厚板自由振动问题的辛本征展开定理

研究了矩形中厚板自由振动问题导出的一个Hamilton算子的本征值问题.在广义位移与内力构成的混合边界条件下,首先求解了相应算子的本征函数.接着,证明了本征函数系的完备性,这为使用分离变量法求解相应问题提供了可行性.最后,根据文中证明的展开定理获得了问题的一般解,并给出了具体的数值算例.     

Node connectivity and arc connectivity of a fuzzy graph

The fuzzy graph approach is more powerful in cluster analysis than the usual graph - theoretic approach due to its ability to handle the strengths of arcs effectively. The concept of node-strength sequence is introduced and is studied in a complete fuzzy graph. Two new connectivity parameters in fuzzy graphs namely, fuzzy node connectivity (κ) and fuzzy arc connectivity (κ^′) are introduced and obtained the fuzzy analogue of Whitney’s theorem. Fuzzy node cut, fuzzy arc cut and fuzzy bond are defined. Fuzzy bond is a special type of a fuzzy bridge. It is proved that at least one of the end nodes of a fuzzy bond is a fuzzy cutnode. It is shown that κ=κ^′ for a fuzzy tree and it is the minimum of the strengths of its strong arcs. The relationships of the new parameters with already existing vertex and edge connectivity parameters are studied and is shown that the value of all these parameters are equal in a compete fuzzy graph. Also a new clustering technique based on fuzzy arc connectivity is introduced.     

ON THE PROPERTIES OF RANDOMLY CONNECTED McCULLOCH-PITTS NETWORKS: DIFFERENCES BETWEEN INPUT-CONSTANT AND INPUT-VARIANT NETWORKS

Abstract

The properties of randomly connected McCulloch-Pitts networks are examined by analytical methods as well as by computer simulation. A classification of the activity transition functions for input-constant networks is provided and a theorem is proved on a necessary and sufficient condition for the symmetry of the activity transition function. The activity transition functions of input-constant networks were compared with those of three types of input variant networks. It is shown that input constant networks are representative for other types of randomly connected networks as long as no more than 50% of the cells are active. Above 50% activation, input constant networks have the most peculiar activity transition function. The time behavior of mean activity in the network was found to be less well predictable in input-variant as compared to input-constant ones. The conditions for the existence of autonomous oscillations arc the same for all types of random connectivity. Implications of the findings for the interpretation of neuroanatomical and neuroembryological observations are discussed.     

A Generalized Sampling Theorem for Non-Stationary Random Processes

Abstract

Gardner [3] has proved sampling theorem for non-stationary random processes. Earlier it was known for stationary processes. Also Kramer [5], using general Kernels, has generalized the Whittaker- Shannon sampling theorem. In the present paper we use the finite Hankel-transform as it appears in the literature and extend it with the help of Kramer's theorem. Further in terms of auto-correlation functions of n-dimensional space, the sampling theorem for n-dimensional non-stationary processes is obtained. We have also extended the definition of auto-correlation function in terms of generalized Kernel in place of Fourier Kernel and then in terms of this, sampling theorem for non-stationary processes is proved. An example using Kernel in terms of Bessel functions is given.     

New Routes and Airport Connectivity

This paper shows how module identification techniques can help airports evaluate the impact of new routes on their network connectivity. Although only carriers can choose whether to open a new route, this research is also of interest to airports and regional governments, who can offer incentives for new connections to desirable destinations. The analysis employs simulated annealing to verify the existence of highly interconnected subsystems, or modules, within the European aviation network. A module is a group of airports with very strong internal links in terms of exchanged seats, but weak connections to the rest of the network. From the standpoint of improving connectivity, we expect that new routes towards large airports belonging to other modules are the most desirable. We also find that the lower the interchange between the modules to be connected, the higher the connectivity gain. We test this hypothesis on all 467 European airports with at least one scheduled flight in autumn 2007.     

Connectivity and Inference Problems for Temporal Networks

Many network problems are based on fundamental relationships involving time. Consider, for example, the problems of modeling the flow of information through a distributed network, studying the spread of a disease through a population, or analyzing the reachability properties of an airline timetable. In such settings, a natural model is that of a graph in which each edge is annotated with a time label specifying the time at which its endpoints “communicated.” We will call such a graph a temporal network. To model the notion that information in such a network “flows” only on paths whose labels respect the ordering of time, we call a path time-respecting if the time labels on its edges are non-decreasing. The central motivation for our work is the following question: how do the basic combinatorial and algorithmic properties of graphs change when we impose this additional temporal condition? The notion of a path is intrinsic to many of the most fundamental algorithmic problems on graphs; spanning trees, connectivity, flows, and cuts are some examples. When we focus on time-respecting paths in place of arbitrary paths, many of these problems acquire a character that is different from the traditional setting, but very rich in its own right. We provide results on two types of problems for temporal networks. First, we consider connectivity problems, in which we seek disjoint time-respecting paths between pairs of nodes. The natural analogue of Menger's Theorem for node-disjoint paths fails in general for time-respecting paths; we give a non-trivial characterization of those graphs for which the theorem does hold in terms of an excluded subdivision theorem, and provide a polynomial-time algorithm for connectivity on this class of graphs. (The problem on general graphs is NP-complete.) We then define and study the class of inference problems, in which we seek to reconstruct a partially specified time labeling of a network in a manner consistent with an observed history of information flow.     

RCC8的一致分割及其算法

区域连接演算（Region Connection Calculus,RCC）是一种用于空间定性表示和推理的形式化模型,如RCC5,RCC8等,其一致性检查被证明是一个NP问题。幸运的是,在其可处理子集上,路径一致性和一致性等价,即便这样也有[O(n3)]的时间复杂度和[O(n2)]的空间复杂度。为了提高一致性检查的效率,提出了一致分割的概念,给出了其定义和成立的充分必要条件,用来将RCC8的约束图在保持一致性的前提下分割成若干个子图,分而求解各个子图的一致性;并随后给出了几种一致分割的充分条件,和相应的高效分割算法。在随机生成的大型、稀疏约束图上的实验表明了一致分割的有效性。