共查询到20条相似文献,搜索用时 15 毫秒
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本文首先讨论了边界表示的物体的形态学运算问题。文中讨论了任意形状的物体,包括凸物体和非凸物体;引入了负形体的概念;并提出了2D和3D连续物体的Minkowski运算的统一算法。利用这一算法,提出了3D任意形体间的变形新算法,把边界表示的物体的形态学运算的概念扩展到任意曲线和任意曲面上,并且介绍了3D物空间中曲线的概念和3D物空间双参数曲面的概念。文中任意形体的3D变形算法能很好地解决具有不同拓扑结构的3D边界表示的物体之间的变形问题。 相似文献
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Current programming languages lack powerful mechanisms for the denotation of composed objects. A constructor for array objects is proposed and shown to be useful for program modifiability and run time efficiency. Constructors to list type objects are also discussed. 相似文献
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WADE系统的支持对象通信的绑定代理 总被引:2,自引:0,他引:2
为了支持基于校园网络的元计算系统WADE的分布式对象的高效通信,提出了一种具有分级体系结构的分布式对象模型。该模型负责建立、定位、管理、删除和迁移对象。论文在讨论对象通信过程和模型的基础上,提出了利用绑定代理技术实现对象通信地址绑定的方法。该方法通过绑定缓冲器和消息缓冲器来提高对象的通信效率,基于双重缓冲的绑定代理技术可以有效提高对象的通信效率。 相似文献
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讨论了SNMP-DMI转换代理实现中需要解决的3个关键问题,并对这3个问题——MIB变量与被管对象可识别变量之间的映射;SNMP协议PDU与被管对象可识别协议或命令之间的转换;转换代理与被管对象之间通讯机制——具体的解决方案进行了详细的阐述,并给出了转换代理实现的框架流程。 相似文献
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多运动目标跟踪是智能视觉监控系统中的关键性的亟待解决的问题,采用二维视觉特征跟踪会在目标相互遮挡时丢失目标特征造成跟踪困难,近年来三维视觉跟踪系统越来越成为热点,利用三维特征能在多目标相互遮挡时更好地识别、跟踪目标,实现多目标遮挡时的精确跟踪,从而全面提高智能视觉监控系统的精确性。总结了近年来基于三维视觉系统的多运动目标跟踪方法,根据采用的不同三维视觉系统分为三类,将每类中具有代表性的方法进行了论述,分析了各典型方法的优缺点,最后提出了进一步研究的主要发展内容和趋势。 相似文献
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A family of techniques for creating intuitively informative shaded images of 4-D mathematical objects is proposed. The rendering of an object in a 4-D world is described by considering step-by-step how objects might be rendered into images in simpler worlds. The mathematical principles needed to compute projected images of objects and their shadows in D dimensions are outlined. The issues involved in producing shaded images of objects in four dimensions, including extending rendering from 3-D to 4-D, smooth shading, and specularity, are discussed. Results of rendering a Steiner surface, torus, and knotted sphere in four dimensions are presented 相似文献
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An approach to the recovery of trajectories of objects in a dynamic scene from stereo images is proposed. The approach is based on the use of a point representation of objects, visual odometry, and a set of algorithms that produce point models of objects and calculate their trajectories using matched 3D point clouds. Results of numerical experiments for synthetic scenes are discussed. 相似文献
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VRML与Java的通信机理实现可视化的研究 总被引:2,自引:0,他引:2
着重就VRML与Java程序结合的方式进行研究,讨论了Java和VRML的通信机理。及其实现从场景中实时获得指定对象的位置坐标、得到指定对象的参数信息、向指定对象发送运动参数、动态控制场景等功能,以构建真正实时交互式的三维虚拟场景,在此基础上实现高桩码头虚拟拼接与浏览。 相似文献
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Correspondence analysis is a multivariate technique that is used for the analysis of discrete data. Its formalism is presented, together with the application to mixed data. Some properties are enumerated. Its use in pattern recognition is discussed both in the context of classification of single objects and samples (collection of objects). 相似文献
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A distributed system is said to be fault‐tolerant if it is able to provide important services despite partial failures of the computers or software objects in the system. These systems are needed to support applications such as remote access and control, virtual mobile offices and wide area collaborative systems where there are chances of failures in the network and software objects. Fault‐tolerance is usually achieved by replicating the objects in the system. Traditional distributed applications constructed using Java RMI (remote method invocation) are not fault‐tolerant because of the lack of support of object replication. The objective of the present work is to design a remote method invocation that supports server object replication. To provide a fault‐tolerant service to the remote client objects, server objects are actively replicated. The problems associated with the method invocation in the context of active server object replication are presented and solutions are discussed and implemented. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
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在不完备信息系统中,对象存在不确定性。基于对象的不确定性,讨论一种不完备信息系统中上、下近似的模糊化,即,上、下近似是论域上的一对模糊集合。一方面,在不完备信息系统中,集合的上、下近似由相似关系确定;另一方面,由于*的存在,使得对象具有不确定性。因此,首先定义了对象的不确定性程度和对象之间的相似度;然后利用对象之间的相似度,通过逻辑关系和相应的函数运算,分别给出了对象隶属于上、下近似集合的隶属度,形式地,该过程可理解为上、下近似集合的模糊化。实例分析说明在不完备信息系统中,考察对象对于上、下近似的隶属度能更直观、合理地反应对象隶属于某一集合的上、下近似的情况。 相似文献
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Object-oriented database management systems: concepts and issues 总被引:1,自引:0,他引:1
Requirements imposed on both the object data model and object management by the support of complex objects are outlined. The basic concepts of an object-oriented data model are discussed. They are objects and object identifiers, aggregation, classes and instantiation mechanisms, metaclasses, and inheritance. Object-oriented models are compared with semantic, relational, and Codasyl models. Object-oriented query languages and query processing are considered. Some operational aspects of data management in object-oriented systems are examined. Schema evolution is discussed 相似文献
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利用基于优势关系的模糊粗糙集模型,讨论了模糊决策信息系统中优化序决策规则的获取问题。利用优势关系定义了模糊目标信息系统中对象的三种属性约简。给出了它们的判定定理,构造相应的区分函数,利用布尔推理技术计算对象的属性约简,得到三类新的优化序决策规则。 相似文献
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论文研究了对象关系数据库管理系统的强制访问控制,在达梦对象关系数据库管理系统的安全对象概念及其对象特性的基础上,给出了标识对象安全级的策略和过滤对象的访问控制策略,重点讨论了过滤对象的约束策略。 相似文献