共查询到20条相似文献,搜索用时 15 毫秒
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In recent years, processor technology has evolved towards multicore processors, which include multiple processing units (cores) in a single package. Those cores, having their own private caches, often share a higher level cache memory dedicated to each processor die. This multi-level cache hierarchy in multicore processors raises the importance of cache utilization problem. Assigning parallel-running software components with common data to processor cores that do not share a common cache increases the number of cache misses. In this paper we present a novel approach that uses model-based information to guide the OS scheduler in assigning appropriate core affinities to software objects at run-time. We build graph models of software and cache hierarchies of processors and devise a graph matcher algorithm that provides mapping between these two graphs. Using this mapping we obtain candidate core sets that each software object can be affiliated with at run-time. These affiliations are determined based on the idea that software components that have the potential to share common data at run-time should run on cores that share a common cache. We also develop an object dispatcher algorithm that keeps track of object affiliations at run-time and dispatches objects by using the information from the compile-time graph matcher. We apply our approach on design pattern implementations and two different application program running on servers using CFS scheduling. Our results show that cache-aware dispatching based on information obtained from software model, decreases number of cache misses significantly and improves CFS’ scheduling performance. 相似文献
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We propose a new parallel ray-tracing hardware architecture in which processors are connected as a ring. Most parallel ray-tracing algorithms subdivide the whole object space into subregions; A processor handles only rays entering the subregion assigned to it. Here we assign each processor objects that are spread over the whole object space. The processors trace rays on their own objects. The respective partial results are combined to form the final image. This scheme is especially suitable for synthesizing animated sequences because objects need not be reallocated for every frame. Preliminary results show a speed-up factor almost linearly proportional to the number of processors. 相似文献
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Vana Kalogeraki Author Vitae P.M. Melliar-Smith Author Vitae 《Journal of Systems and Software》2008,81(7):1144-1162
This paper describes a Resource Management System for a soft real-time distributed object system that is based on a three-level feedback loop. The Resource Management System employs a profiling algorithm that monitors the usage of the resources, a least laxity scheduling algorithm that schedules the methods of the tasks, and hot spot and cooling algorithms that allocate and migrate objects to balance the loads on the resources. The Resource Management System consists of a single Resource Manager for the distributed system, and a Profiler and a Scheduler located on each of the processors in the distributed system. 相似文献
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WADE是一个基于校园网络的面向对象的元计算系统,通过分布式对象模型实现广域异构资源的一致管理,提出了一种4级对象层次结构支持模型的组织与实现,对象命名代理负责用户与系统的接口,映射用户对象标识符UOID到系统对象标识符SOID,对象通信代理为对象绑定通信地址,建立通信对象标识符COID,对象存储管理器则负责对象的惰性保存,并通过永久对象标识符POID识别惰性对象,WADE采用了双Cache缓冲机制,有利于提高对象的操作与通信性能。 相似文献
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对象组装及其关联语义的自动维持 总被引:2,自引:0,他引:2
讨论了对象组装概念及其对象关联语义的自动维持问题.在给出对象组装的模型之后,还对其语言描述、实现机制进行了阐述.它是基于专门用于组装的对象挂接,而不是常规对象接口.由此实现了面向问题域的对象间关联的动态建立和关联语义的自动维持,从而增加了对象建模的描述能力和使用的灵活性,降低了对象接口的实现和使用的复杂度.作为对象描述和对象作用的机制,它为软件IC的实现提出了新思想,其应用、规范和标准化将为软件设计的工业化生产提供新的设计技术. 相似文献
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We describe the design and implementation of system architecture to support object introspection in C++. In this system, information is collected by parsing class declarations, and is used to build a supporting environment for object introspection. Our approach is non‐intrusive because it requires no changes in the original class declarations and libraries; hence, binary compatibility between objects before and after the addition of introspective capability is ensured. This is critical if one wants to integrate third‐party class libraries, which are often supplied as black boxes and allow no modification, into highly dynamic applications. We present two applications: the first is automatic I/O support for C++ objects, and the other is interactive exercise of dynamically loaded C++ class libraries. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
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In the conventional object model, encapsulated objects interact by messages that result in method invocations on the destination object. A message is delivered directly at the destination object. As a result of the direct deliveries, the message control code performing intermediate message manipulations cannot be abstracted out separately from the message processing code in the destination object without sacrificing the transparency of the intermediate message control. We propose the filtered delivery model of message passing for object-oriented languages to provide the separation of message control from message processing in a transparent manner. An interclass relationship, called a filter relationship, is introduced. As a consequence, a filter object can intercept and manipulate messages sent to another object called its client via filter member functions. A filter member function in a filter object can intercept a particular member function invocation on its client object. The filtered delivery model supports both upward and downward filtering mechanisms, facilitating interception of an upward message and its return message value. Filter objects can be plugged or unplugged at runtime. Binding of filter member functions to corresponding member functions in the client is selective and dynamic. The filtered delivery model is developed for the C++ object-oriented language; its applications are described and implementation is discussed. © 1997 John Wiley & Sons, Ltd. 相似文献
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设计了一种基于FPGA的运动目标的检测系统,采用模块化设计和流水线的处理方式,充分利用了FPGA高速并行处理特点以及DDR2 SDRAM大容量特性.系统采用了单高斯背景建模的背景差分法同时结合帧间差分法的方式实现对运动目标的检测.实践测试结果表明,该目标检测系统能够有效的实现运动目标的检测,且检测效果良好,满足实时性需求. 相似文献
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面向对象数据库中对象的存储和操作算法 总被引:9,自引:1,他引:9
面向对象数据库管理系统的核心是把现实世界的描述为对象,数据库的存储,操作和管理都以对象为依据。对象可以是简单的,也可以是复杂的。复杂对象中引用了其它的对象。结合我们开发的面向对象的工程数据库管理系统论述了对复杂对象的物理存储,内存映象方法和对象操作方法的实现技术。 相似文献
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支持对象间关系的程序设计语言研究 总被引:3,自引:0,他引:3
在论述了面向对象技术中对象间的关系作为第一级建模概念的重要性之后,该文设计并实现了显式支持对象间关系的RCPP(relational C++)语言.它提供了显式描述对象间关系特性和语义的机制,利用关系来动态地控制对象行为的作用和传播.它的运行是通过一个转换器把RCPP代码翻译成C++代码,再经C++环境编译后,形成可执行程序而实现的.文章对RCPP语言的模型、语言提供的服务以及具体系统的描述和实现作了深入阐述. 相似文献
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B.W. Heal 《Computer Graphics Forum》1989,8(3):199-206
A processing pipeline solution to the generation and display of octree encoded 3-D objects is described. Particular emphasis is given to an algorithm which removes that part a of linear octree code which describes parts of the object which are invisible from a prescribed viewing position. The scope of the algorithm is restricted to viewing directions which are parallel to the Cartesian axes and to orthogonal projections. The algorithm is specifically designed to operate as a single stage within a pipeline of processes. 相似文献
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Direction is an important spatial concept that is used in many fields such as geographic information systems(GIS) and image interpretation. It is also frequently used as a selection condition in spatial queries. Previous work has modeled direction as a relational predicate between spatial objects. Conversely, in this paper, we model direction as a new kind of spatial object using the concepts of vectors, points and angles. The basic approach is to model direction as a unit vector. This novel view of direction has several obvious advantages: Being modeled as a spatial object, a direction object can have its own attributes and operation set. Secondly, new spatial data types such as oriented spatial objects and open spatial objects can be defined at the abstract object level. Finally, the object view of direction makes direction reasoning easy and also reduces the need for a large number of inference rules. These features are important in spatial query processing and optimization. The applicability of the direction model is demonstrated by geographic query examples. 相似文献
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面向对象的并行程序设计提供了类似于共享内存模型对通讯和计算的抽象能力,从而非常适合于大型并行软件系统的开发.但是基于远程对象调用的分布式对象的实现效率一直是面向对象方法在分布式/并行程序设计中得到广泛应用的障碍.本文介绍了并行机MANNA上所采用的面向对象的并行程序设计模型——Dual-Object模型.该模型通过引入从语义角度出发给出的数据一致特性的描述,在一定程度上解决了实现效率低下的问题.其次,文章通过程序设计实例详细地讨论了基于Dual-Object模型的扩展C++并行程序设计,并给出了部分实际测试结果. 相似文献
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在移动对象数据库中,移动对象的数量可能会经常变化,这就给索引技术提出了新的挑战。移动对象索引技术的效率是移动对象数据库的一个重要研究课题。为了防止数据库由于移动对象数量的变化而导致性能锐减,本文在网格文件索引的基础上提出了一种动态网格索引技术。通过实验比较显示,它相对于静态索引具有更好的适应性。 相似文献
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Li Tianzhu 《计算机科学技术学报》1995,10(4):380-384
The concept of object identity and implementation of object identity in some systems have been explained in literature.Based on an analysis on the idea of data scheme in ANSI/X3/SPARC,this paper presents the concept of full-identity,which includes entity identity,conceptual object identity,and internal object identity,In addition,the equality of objects,which is richer and more practical,is discussed based on the full identity of objects.Therefore,the semantics and constructions of the identity for the complex objects are fully observed,and some appliactions in object management,version management,and user interface are found.Also,it could support the combination of O-O model with V-O model. 相似文献
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随着计算机视觉和人工智能技术的快速发展,目标检测受到了更加广泛的关注。由于小目标像素占比小、语义信息少、易受复杂场景干扰以及易聚集遮挡等问题,导致小目标检测一直是目标检测领域中的一大难点。目前,视觉的小目标检测在生活的各个领域中日益重要。为了进一步促进小目标检测的发展,提高小目标检测的精度与速度,优化其算法模型,本文针对小目标检测中存在的问题,梳理了国内外研究现状及成果。首先,分别从小目标可视化特征、目标分布情况和检测环境等角度对小目标检测的难点进行了分析,同时从数据增强、超分辨率、多尺度特征融合、上下文语义信息、锚框机制、注意力机制以及特定的检测场景等方面系统总结了小目标检测方法,并整理了在框架结构、损失函数、预测和匹配机制等方面发展的较为成熟的单阶段小目标检测方法。其次,本文对小目标检测的评价指标以及可用于小目标检测的各类数据集进行了详细介绍,并针对部分经典的小目标检测方法在MSCOCO(Microsoft common objects in context)、VisDrone2021(vision meets drones2021)和Tsinghua-Tencent100K等数据... 相似文献
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Nicolas CEBRON 《Frontiers of Computer Science》2012,6(2):143-153
When we think of an object in a supervised learning setting, we usually perceive it as a collection of fixed attribute values. Although this setting may be suited well for many classification tasks, we propose a new object representation and therewith a new challenge in data mining; an object is no longer described by one set of attributes but is represented in a hierarchy of attribute sets in different levels of quality. Obtaining a more detailed representation of an object comes with a cost. This raises the interesting question of which objects we want to enhance under a given budget and cost model. This new setting is very useful whenever resources like computing power, memory or time are limited. We propose a new active adaptive algorithm (AAA) to improve objects in an iterative fashion. We demonstrate how to create a hierarchical object representation and prove the effectiveness of our new selection algorithm on these datasets. 相似文献