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1.
基本的目标检测任务是在图像中识别目标,并标注目标的类别和位置信息。但是,很多应用中的目标检测任务常常带有语义约束,典型的包括单类别目标的数量约束和多个目标之间的空间位置约束。如在基于视频的生产安全监控系统中,目标检测不仅要识别和标定安全防护装备,还要检测这些安全防护装备是否被规范穿戴。提出了一种目标检测中语义约束检查算法,定义一种语义约束的模型,然后对图像进行带有语义信息的目标检测,最终对目标检测结果与语义约束进行一致性判定。以电力施工防护装备检查的实际需求和现场安监视频为例,验证了所提出的目标检测中语义约束检查算法的有效性。  相似文献   

2.
张波  向阳 《计算机科学》2008,35(7):161-165
依据模型知识的特性,定义了模型描述本体和任务求解本体,为模型提供语义支持.模型语义分为描述语义和行为语义.基于描述语义的相似性判定,模型可进行潜在冲突预测;然后根据任务求解本体的定义,模型通过行为语义交互,进行行为协商;而在执行过程中,模型需要为每一个操作申请资源,因此模型根据模型描述本体和描述语义对资源申请进行协商,从而得到互不冲突的操作执行序列,消除冲突.最后通过实验分析验证算法的有效性.  相似文献   

3.
采用逻辑的方法在完备信息系统中展开讨论,通过对公式及公式语义的定义,引出了公式的语义在信息系统上均匀分布的概念。为了对此进行研究,利用Pawlak上近似定义了逻辑公式的粗糙真,其目的就是通过公式的粗糙真对公式语义的均匀分布进行分析。进而,得到了关于粗糙真的相应结论以及如何利用这些结论判定析取特征公式粗糙真的算法。在此基础上,通过信息系统的实例讨论了粗糙真在判定析取特征公式语义均匀分布的具体应用。  相似文献   

4.
一种有效的用于数据挖掘的动态概念聚类算法   总被引:11,自引:0,他引:11  
郭建生  赵奕  施鹏飞 《软件学报》2001,12(4):582-591
概念聚类适用于领域知识不完整或领域知识缺乏时的数据挖掘任务.定义了一种基于语义的距离判定函数,结合领域知识对连续属性值进行概念化处理,对于用分类属性和数值属性混合描述数据对象的情况,提出了一种动态概念聚类算法DDCA(domain-baseddynamicclusteringalgorithm).该算法能够自动确定聚类数目,依据聚类内部属性值的频繁程度修正聚类中心,通过概念归纳处理,用概念合取表达式解释聚类输出.研究表明,基于语义距离判定函数和基于领域知识的动态概念聚类的算法DDCA是有效的.  相似文献   

5.
基于语义的主题爬行策略   总被引:1,自引:0,他引:1  
叶育鑫  欧阳丹彤 《软件学报》2011,22(9):2075-2088
为使主题爬行能够充分利用资源的语义信息,提出基于语义的主题爬行策略.该策略利用领域本体刻画爬行主题,将本体语义映射到关键词表.通过定义断言集一致性扩展和域值关联推理任务,推演关键词间语义关系.在定义网页主题概念的基础上,结合本体推理方案提出主题概念的语义叠加效应模型.最后,利用主题概念的语义包含关系判定URLs抓取顺序.实验结果表明,该语义主题爬行策略在抓取收获率和爬行效率上优于现有同类方法,该方案有效、可行.  相似文献   

6.
传统的数字游戏只注重底层实体级别的交互协同,不支持多层次群体协同关系描述和协同规划描述,且很少有形式化理论支持.描述任务逻辑结合了描述逻辑的知识表示结构和任务逻辑的任务语义.描述任务逻辑方法对数字游戏中的协同关系和协同规划进行了形式化描述,给出了任务和规划可完成性的定义,以及联合策略下的规划可完成性的判定理论.通过示例说明,描述任务逻辑方法能够准确地描述虚拟群体高层指挥关系的任务交互语义,同时又能提供协同规划可完成性的可判定的推理验证服务.  相似文献   

7.
在XML文档中,如果某些元素的定义不能准确地表示元素的语义,就会使在查询特定内容,而又缺少上下文语义关系的情况下,不能准确得到查询结果,也就是查询二义性。为了克服这个问题,提出了XML环和其他一些相关的概念,并在此基础上分析了此类文档的特征,给出了XML文档中是否存在环的判定算法,最后提出重新定义元素,从而消除元素二义性的方法来消除XML文档中的环。  相似文献   

8.
郑高山  应时  吴睿 《计算机科学》2016,43(8):131-136
在应用软件中广泛使用的访问控制模型不能根据用户上下文来动态改变资源的访问权限。针对上述问题提出一种基于语义技术的访问控制方法,实现了对用户的动态授权。提出基于语义信息的用户模型和资源模型并构建面向用户模型和资源模型的基础本体,定义一组与访问控制相关的语义规则及推理规则,并设计基于语义推理过程的判定算法。访问控制过程是接收并分析访问请求,根据语义规则从显示的本体知识中获取相关联的用户信息,调用判定算法得出用户与资源间的访问权限关系。最后通过某综合减灾应用系统案例来验证该方法的有效性。  相似文献   

9.
针对如UC/OS-Ⅱ等轻量级的操作系统,通过重新定义老化判定时间,提出了不对称老化程度算法模型,完善了其任务调度算法,使之更加灵活,在保证其原有任务优先级层次体系结构的同时,更为有效地解决任务"饥饿",从而使嵌入式操作系统更加高效,更加适应技术的发展.  相似文献   

10.
基于描述任务逻辑的群体组织协同关系模型   总被引:1,自引:0,他引:1       下载免费PDF全文
群体组织模型是深入研究群体协同行为的基础,而现有的组织模型大多集中在对Agent组织的结构或个体低层指令级的交互上,不能描述组织高层的动态任务交互。提出一个新的群体组织协同关系模型GRNA。该模型包含两个子模型:认知模型和交互模型。认知模型构建于领域本体之上,为GRNA模型提供准确的术语定义;交互模型则基于描述任务逻辑理论,反映了群体的任务协同语义。实例分析表明,GRNA支持对群体规范和能力的描述,提供了组织任务可完成性的可判定的推理服务,能够描述组织的高层任务交互语义。  相似文献   

11.
Web服务组合方法综述   总被引:7,自引:2,他引:5       下载免费PDF全文
Web服务组合通过重用已有的Web服务满足用户高质量的应用需求,是面向服务架构研究领域的热点问题。该文对当前Web服务组合的研究现状进行了综述,分析了WSC的概念和实现框架。根据研究侧重点及其依赖的技术基础,将WSC方法归为两大类别——基于工作流、状态演算和进程代数模型描述的过程驱动的组合方法和基于语义描述的自动服务组合方法。对WSC的评价模型及其研究与应用中所面临的挑战进行了论述。  相似文献   

12.
Graph transformation systems are a well-founded and adequate technique to describe the syntax of visual modeling languages and to formalize their semantics. Moreover, graph transformation tools support visual model specification, simulation and analysis on the basis of the rich underlying theory.Despite the benefits of model validation by simulation, sometimes it is preferable for users to see the model's behavior not in the abstract layout of the formal model, but as scenarios presented in the layout of the specific application domain. Hence, we propose the integration of a domain-oriented animation view with the model transformation system. An animation view allows to define scenario animations in a systematic way based on the formal model. The specification of the well-known Dining Philosophers system as algebraic high-level Petri net serves as running example for the extension of the model by an animation view and the derivation of animation rules from the model transformation system. A scenario animation then is obtained as transformation by applying the animation rules to model states. This visualizes the behavior of the model in the layout of philosophers sitting around a table and eating with chopsticks. A prototypical implementation of the concepts in GenGED, a visual language environment, is presented.  相似文献   

13.
We propose an approach to the analysis and design of software production processes that is based on a new paradigm which we coin ‘PETAN’. It is a blend of concepts from Petri nets theory and activity nets theory. The paper reviews the relevant concepts from activity nets and demonstrates the applicability of the new paradigm by a sample implementation to real life software production processes through simulation using SLAM II language.  相似文献   

14.
The aim of this paper is to present a generic component framework for system modeling that satisfies main requirements for component-based development in software engineering. In this sense, we have defined a framework that can be used, by providing an adequate instantiation, in connection with a large class of semi-formal and formal modeling techniques. Moreover, the framework is also flexible with respect to the connection of components, providing a compositional semantics of components. This means more precisely that the semantics of a system can be inferred from the semantics of its components. In contrast to other component concepts for data type specification techniques, our component framework is based on a generic notion of transformations. In particular, refinements and transformations are used to express intradependencies, between the export interface and the body of a component, and interdependencies, between the import and the export interfaces of different components. The generic component framework generalizes module concepts for different kinds of Petri nets and graph transformation systems proposed in the literature, and seems to be also suitable for visual modeling techniques, including parts of the UML, if these techniques provide a suitable refinement or transformation concept. In this paper the generic approach is instantiated in two steps. First to high-level replacement systems generalizing the transformation concept of graph transformations. In a second step it is further instantiated to low-level and high-level Petri nets. To show applicability we present sample components from a case study in the domain of production automation as proposed in a priority program of the German Research Council (DFG).  相似文献   

15.
An operator net is a graph consisting of nodes and directed arcs. While operator nets are syntactically similar to dataflow nets, they completely separate the operational semantics from the mathematical semantics. In this paper we define an operational semantics for operator nets that intuitively corresponds to communication in a distributed system. The operational semantics of operator ator nets provide a formal model for a distributed system that is an intermediate point between the actual system and a mathematical model. Abstract properties are expressed using relations on events and messages of an operator net. Corresponding operational specifications can be written using Lucid equations that define a node as a mathematical function on infinite history sequences. The operational specifications are executable and can be easily transformed into a practical implementation of the system. Examples of such specifications are included in the paper.Janice Glasgow is an associate professor in the Department of Computing and Information Science at Queen's University. She received her M. Math and Ph.D. degrees from the University of Waterloo. Dr. Glasgow's current research interests include programming language semantics and logics for reasoning about programming.Glenn H. MacEwen r received the B.Eng. degree in electrical engineering from McGill University, Montreal, P.Q., Canada, in 1962 and the M.Sc. and Ph.D. degrees in computer science from the University of Toronto, Toronto, Ont., Canada in 1967 and 1971, respectively. Since 1970 he has been with the Department of Computing and Information Science at Queen's University, Kingston, Ontario. He served as Head from 1982 to 1987 and is currently a Professor in the department. He is also a director and consultant to Andyne Computing Limited. His research interests include software engineering, computer security, and real-time systems. Dr. MacEwen is a senior member of the Institute of Electrical and Electronics Engineers, and a member of the Association for Computing Machinery and the Association of Professional Engineers of Ontario.  相似文献   

16.
The basis for this paper are the concepts of parameterization and implementation of abstract data types which have been developed in the theory of algebraic specifications with initial algebra semantics. In this paper we combine both concepts defining implementations of parameterized data types and studying the compatibility of parameter passing and implementation of parameterized data types. In our main result we show that parameter passing commutes with implementation. This is an important step in order to apply the theory of algebraic specifications to development and stepwise refinement of software systems. We illustrate our notion and results by a small example implementing binary trees over arbitrary data by corresponding strings with brackets. Finally we consider the problem of 2-dimensional compatibility of parameter passing and implementation and discuss the kind of compatibility results which have been shown by other authors in the case of loose and final algebra semantics.  相似文献   

17.
针对如何在镜头基础上进行聚类,以得到更高层次的场景问题,提出了一个基于语义的场景分割算法。该算法首先将视频分割为镜头,并提取镜头的关键帧。然后计算关键帧的颜色直方图和MPEG-7边缘直方图,以形成关键帧的特征;接着利用镜头关键帧的颜色和纹理特征对支持向量机(SVM)进行训练来构造7个基于SVM对应不同语义概念的分类器,并利用它们对要进行场景分割的视频镜头关键帧进行分类,以得到关键帧的语义。并根据关键帧包含的语义概念形成了其语义概念矢量,最后根据语义概念矢量通过对镜头关键帧进行聚类来得到场景。另外.为提取场景关键帧,还构建了镜头选择函数,并根据该函数值的大小来选择场景的关键帧。实验结果表明,该场景分割算法与Hanjalic的方法相比,查准率和查全率分别提高了34.7%和9.1%。  相似文献   

18.
A large variety of systems can be modelled by Petri nets. Their formal semantics are based on linear algebra which in particular allows the calculation of a Petri net’s state space. Since state space explosion is still a serious problem, efficiently calculating, representing, and analysing the state space is mandatory. We propose a formal semantics of Petri nets based on executable relation-algebraic specifications. Thereupon, we suggest how to calculate the markings reachable from a given one simultaneously. We provide an efficient representation of reachability graphs and show in a correct-by-construction approach how to efficiently analyse their properties. Therewith we cover two aspects: modelling and model checking systems by means of one and the same logic-based approach. On a practical side, we explore the power and limits of relation-algebraic concepts for concurrent system analysis.  相似文献   

19.
This paper1 presents ways of implementing dependable distributed applications designed using the Coordinated Atomic Action (CAA) paradigm. CAAs provide a coherent set of concepts adapted to fault tolerant distributed system design that includes structured transactions, distribution, cooperation, competition, and forward and backward error recovery mechanisms triggered by exceptions. DRIP (Dependable Remote Interacting Processes) is an efficient Java implementation framework which provides support for implementing Dependable Multiparty Interactions (DMI). As DMIs have a softer exception handling semantics compared with the CAA semantics, a CAA design can be implemented using the DRIP framework. A new framework called CAA-DRIP allows programmers to exclusively implement the semantics of CAAs using the same terminology and concepts at the design and implementation levels. The new framework not only simplifies the implementation phase, but also reduces the final system size as it requires less number of instances for creating a CAA at runtime. The paper analyses both implementation frameworks in great detail, drawing a systematic comparison of the two. The CAAs behaviour is described in terms of Statecharts to better understand the differences between the two frameworks. Based on the results of the comparison, we use one of the frameworks to implement a case study belonging to the e-health domain.  相似文献   

20.
Petri网的硬件实现   总被引:12,自引:1,他引:12  
赵不贿  景亮  严仰光 《软件学报》2002,13(8):1652-1657
Petri网是异步并发现象建模的重要工具,Petri网的硬件实现将为并行控制器的设计提供有效的途径.给出了几种Petri网系统的硬件实现方法,包括带抑制弧和允许弧的C/E系统、P/T系统、T-时延Petri网系统;给出了硬件实现中非纯网的处理方法.首先讨论实现各种Petri网的逻辑电路;然后用ABEL语言对逻辑电路进行描述;最后给出了一个用解释Petri网描述的服务系统的例子,说明如何使用硬件(CPLD)实现的方法.实验结果表明了上述方法的正确性.这对于离散事件动态系统控制器的设计,尤其是片上并行控制器、多处理器芯片的设计都具有十分重要的意义.  相似文献   

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