Measurement of cryptographic capability protection algorithms

A capability is an unforgeable, unstealable ticket which allows access to an object in a computer system or network. In a single computer, hardware mechanisms can be used to implement capabilities; in a network, there can be many different kinds of computers, some or all of which may not have the necessary hardware to implement capabilities. However, it is possible to implement capabilities in a network using cryptography. Capability-based protection using secret-key cryptography is currently being implemented in LLNL's Octopus Network. The protection algorithms being implemented are explained in detail. Some hypothetical operating system kernel calls and their operation are shown. Actual performance measurements for the proposed crytographic operations and operating system functions are presented. The trade-offs between performing the operations entirely in a host computer and performing them using an encryption unit attached to the host as a peripheral device are discussed.     

计算机内存的优化及管理浅析

信息总量、网络浏览人数以及人们对网络享受需求的增加,促使着信息制作水平的提高,制作水平的提高在给人们带来了更好的视觉和听觉享受的同时,也对计算机的硬件系统提出了巨大的考验.计算机内存作为计算机硬件系统的重要组成部分,能否对内存做好合理的划分,对计算机的体验具有重要的意义.     

气象卫星资料虚拟存储系统设计与实现

利用服务器连接（SAS）技术和存储局域网（SAN）技术构建气象卫星资料存储系统。实现群集环境中计算机系统间的存储资源共享,设计虚拟存储管理软件对不同的物理存储设备进行逻辑管理,可以简化存储设备的使用,可以提高系统运行效率,国家卫星气象中心的气象卫星资料存储系统的运行结果表明,虚拟存储是解决群体环境中不同物理存储设备有效使用的一条切实可行的技术路线。     

集群作业管理系统的分层实现模型

集群服务器模式的作业管理系统通过在集群系统中提供多虚拟服务模式的作业管理服务器,能够解决用户响应效率低、资源利用率低等问题,提高了作业的执行效率。提出了集群作业管理系统的分层实现模型,并具体分析了各层的详细实现,该模型显著提高了作业管理系统的可用性和可扩展性。     

内容管理系统存储层的设计与实现

为有效达到内容管理系统在海量数据的存储,以及在高并发请求下仍能快速响应用户的请求的目的,在研究了传统存储管理方式和分析了在系统中使用关系数据库将会遇到的问题后,采用开源软件Hadoop作为底层分布式存储基础,设计和实现了此时的内容管理系统的存储层,以满足系统快速读取内容的需求。介绍了系统的内容组织管理模型,针对系统快速读写内容的需求,对读写机制进行了改进、优化和封装,并通过实验测试来验证正确性和可行性。     

iSCSI存储解决方案的设计与实现

分析了存储技术的发展现状,介绍了最新的iSCSI协议及其优势,提出了一种基于虚拟iSCSI存储通道技术的iSCSI存储解决方案的构想,给出了此构想的设计和实现的方法和此方案的文件传输速率测试数据,并做了简要的分析。     

一种内存管理技术的研究与实现

内存管理在计算机系统设计中是及其重要且必须的部分.高效的内存分配,垃圾回收和整理,在并行,分布式和实时应用中变的越来越重要.提出了一种利用二叉树来管理可利用内存分区的算法,并通过试验得出的数据分析,表明为什么该方法比其它算法更为方便高效,实现起来也比较简单易行.     

A data management scheme for effective walkthrough in large-scale virtual environments

As the complexity of virtual environments increases, it becomes a critical issue to maintain the quality of a walkthrough experience. In this paper, we propose an effective data management scheme to address this issue in client-server architecture. First, we propose using real-time scene management to manage the computing resources on the client side by reducing the amount of transmitted geometry data. Second, we propose a prioritized most likelihood movement model to prefetch potential future objects based on the users current motion intention. Lastly, a hybrid coherence cache model is proposed to take advantages of both the temporal and spatial localities of the walkthrough process. We have done extensive experiments to demonstrate how these techniques can improve the effectiveness of walkthrough in a large virtual environment.     

虚拟过程工程数据管理系统的设计与实现

为实现对工业装置内流体流动与传递过程的三维实时高精度模拟,中国科学院过程工程研究所提出了虚拟过程工程(VPE)的构想。为存储和管理在VPE实验过程中产生的海量实时实验数据和模拟数据,本文对VPE的数据管理系统进行了需求分析和功能设计,所实现的数据管理系统包含海量数据存储、底层通信协议、数据实时交互与数据管理工具等部分。该系统目前运行良好,为VPE 1.0提供了可靠的功能支撑。     

一种嵌入式安全内存管理的设计与实现

针对电力应用系统对嵌入式操作系统的实时性和安全性要求,以目前流行的嵌入式操作系统uC/OS-Ⅱ内核为基础,巧妙地应用伙伴算法增强了内存管理模块的功能,并实现了存取控制和审计跟踪等安全功能,同时解决了内存空间的泄漏问题.经测试,本设计能很好的满足电力应用的要求.     

提高存储资源利用率的存储虚拟化技术研究

随着存储数据的爆炸式增长,存储空间的迫切需求,虚拟存储技术已经广泛应用到存储系统中.根据操作系统中内存管理的虚拟内存机制,将其扩展引入到整个存储系统的管理中,并与传统的存储虚拟化技术相结合,提出了双层次存储虚拟化的结构,实现了逻辑层和虚拟层的双层虚拟,以屏蔽存储设备的异构性,极大提升存储资源利用率.     

基于逻辑链接的网格虚拟存储子系统

虚拟存储是存储技术的发展趋势,将广域范围内异构的存储资源加以抽象通过虚拟的、统一的方式为用户提供高效,可靠的存储空间.在分析了网格环境下虚拟存储的特点后,提出了系统架构,阐述了系统结构和主要技术,并基于逻辑链接在某网格服务系统内实现了虚拟存储.最后就现有主流系统与该系统做了分析比较.     

Design and implementation of the virtual machine constructing on register

The technology of virtual machines is widely applied in many fields, such as code transplanting, cross-platform computing, and hardware simulation. The main purpose is to simulate the environment of general hardware by means of software and realize the operation of byte codes in processor. Virtual machines are commonly used to distribute programs in an architecture-neutral format, which can easily be interpreted or compiled. A long-running question in the design of virtual machines is whether stack architecture or register architecture can be implemented more efficiently with an interpreter. After introducing the basic theory, a solution to designing and realizing virtual machine constructing on register processor proposed in this paper, which gives a preliminary study on simulating the process of instructions in Intel x86.     

uClinux系统分析

分析了uChnux与标准Linux的主要差异，并且对uChnux程序设计的要点进行了阐述。     

Linux虚存机制在嵌入式系统背景下的分析

在嵌入式应用领域里，从因特网设备到专用控制系统，Linux操作系统前景都很光明，但Linux虚拟内存管理机制对于一个嵌入式系统来讲往往是多余的，更重要的是影响系统的实时性能，对Linux的虚拟内存管理机制进行了分析，并从源码级提出了一种改进方案，以适用于嵌入式Linux。     

嵌入式实时系统内存管理策略

嵌入式系统内存配置较小,不能采用一般桌面系统的内存管理方式,选取合适的内存管理策略在嵌入式系统设计中起着重要的作用。介绍了嵌入式系统设计中内存管理的范围、对内存分配的要求以及可能出现的问题,对内存分配的方式进行了详细的阐述,给出了内存碎片、内存丢失、执行时间不固定等问题的解决方法。     

An implementation of distributed shared memory

Shared memory is a simple yet powerful paradigm for structuring systems. Recently, there has been an interest in extending this paradigm to non-shared memory architectures as well. For example, the virtual address spaces for all objects in a distributed object-based system could be viewed as constituting a global distributed shared memory. We propose a set of primitives for managing distributed shared memory. We present an implementation of these primitives in the context of an object-based operating system as well as on top of Unix.     

虚拟运行环境描述管理工具的研究和实现

针对分布式网络环境中虚拟运行环境的描述、部署和管理问题,设计和实现了一个图形化的虚拟运行环境的描述、部署和管理系统,该系统整合虚拟机技术,通过图形化的方式来描述目标虚拟运行环境的网络拓扑,配置和部署环境中的虚拟机,并提供了对其中虚拟机基本的管理和控制功能.具有通用性、高可扩展性和灵活性的特点.可用于网格以及其它分布式系统.     

Proactive workload management in dynamic virtualized environments

Recently, with the improvement of Cloud systems technologies and the essential advantages they can provide such as availability, scalability, and costs saving; massive domains in the IT industry are directing their business to the Cloud. To fit the computing demands of this trend along with nowadays fluky applications (e.g. social networks, media contents), Cloud systems require rapid resource changes. As a result, the workload management in a virtualized environment becomes a complex task. In this paper we propose a new proactive workload management model for virtualized resources to inspect the workload behavior of the running Virtual Machines, and to assent an appropriate scheduling and resource consolidation schema in order to improve the system efficiency, utilization, and throughput. We have carried out our model by modifying Xen Cloud Platform, then we tested the model performance through different representative benchmarks. The results show that the Proactive model can decrease the average response time remarkably.