Comparing data type specifications via their normal forms

A simple technique is presented for verifying that two abstract data type specifications are equivalent in that they have isomorphic initial algebras. The method uses normal forms to attempt reducing the number of equations to be checked. It is applied to a simple example and some extensions, and related problems are also discussed.     

Comparing system level power management policies

Reducing power consumption is a challenge to system designers. Portable systems, such as laptop computers and personal digital assistants (PDAs), draw power from batteries, so reducing power consumption extends their operating times. For desktop computers or servers, high power consumption raises temperature and deteriorates performance and reliability. Soaring energy prices and rising concern about the environmental impact of electronics systems further highlight the importance of low power consumption. Power reduction techniques can be classified as static and dynamic. Static techniques, such as synthesis and compilation for low power, are applied at design time. In contrast, dynamic techniques use runtime behavior to reduce power when systems are serving light workloads or are idle. These techniques are known as dynamic power management (DPM). DPM can be achieved in different ways; for example, dynamic voltage scaling (DVS) changes supply voltage at runtime as a method of power management. Here, we use DPM specifically for shutting down unused I/O devices. We built an experimental environment on a laptop computer running Microsoft Windows. We implemented existing power management policies and quantitatively compared their effects on power saving and performance degradation     

基于数据中台架构的数据管理研究

为了解决数据问题,数据管理技术的价值得到了多家公司的认可,并出现了许多关于数据管理的想法和研究。然而,在实际的业务数据管理中,仍然存在一些问题。因此,文章基于对数据中台架构的数据管理进行了深入分析。     

基于Multi-Agent和HLA的口岸物流仿真

针对高层体系结构（ HLA）仿真建模技术的仿真联邦成员缺乏智能性和Multi-Agent仿真方法分布通信协同能力较差的问题。提出了一种集成两者的自适应中间件的方法,通过自适应中间件实现了两者集成的数据转换、通信及控制等功能,并进行实例验证。结果表明此方法在最小改变的情况下保证了集成开发的灵活性及方法的可行性、实用性和可靠性。     

一种体系结构层方面组合的冲突处理方法*

当横切关注点组合到主关注点时,可能出现冲突的情况。该冲突导致体系结构设计难以决策,然而目前也缺乏有效的对这些可能冲突进行处理的方法。针对这一问题,提出了一种体系结构层方面组合的冲突处理方法。该方法结合AHP和加权平均思想的优点,并在定量分析时对结果进行一致性评估,达到了有效解决问题的目的,从而有助于提高软件体系结构设计的质量。最后通过案例和实验证实该冲突处理方法的有效性。     

A decoupled federate architecture for high level architecture-based distributed simulation

A number of research issues arise in executing large scale High Level Architecture (HLA) based distributed simulations. Among these issues distributed simulation cloning, fault tolerance and Grid enabled architecture are particularly important and challenging. This paper presents a Decoupled Federate Architecture as the underlying infrastructure to facilitate a solution to each of the above issues.     

Aurora: a new model and architecture for data stream management

This paper describes the basic processing model and architecture of Aurora, a new system to manage data streams for monitoring applications. Monitoring applications differ substantially from conventional business data processing. The fact that a software system must process and react to continual inputs from many sources (e.g., sensors) rather than from human operators requires one to rethink the fundamental architecture of a DBMS for this application area. In this paper, we present Aurora, a new DBMS currently under construction at Brandeis University, Brown University, and M.I.T. We first provide an overview of the basic Aurora model and architecture and then describe in detail a stream-oriented set of operators.Received: 12 September 2002, Accepted: 26 March 2003, Published online: 21 July 2003Edited by Y. Ioannidis     

Oasis: an architecture for simplified data management and disconnected operation

Oasis is an asymmetric peer-to-peer data management system tailored to the requirements of pervasive computing. Drawing upon applications from the literature, we motivate three high-level requirements: availability, manageability, and programmability. Oasis addresses these requirements by employing a peer-to-peer network of weighted replicas and performing background self-tuning. In this paper, we describe our architecture, our consistency-control mechanism, and an initial implementation. Our performance evaluation and the implementation of three applications suggest that Oasis offers good availability and performance while providing a simple API and a familiar consistency model.     

A high level data structure—The grid

Grids are arrays that can have any shape: grid elements need not be connected to each other (e.g., a grid may be pyramid-like or two disjoint rectangular pieces). Programs using grids are smaller, semantically clearer, more general and easier to modify than programs that simulate non array-like shapes. We present a notation for specifying grids in PASCAL. Grids have been implemented as an extension to FORTRAN.     

基于高层体系结构的军事工程毁伤与防护仿真系统

为满足军事工程毁伤分析、防护评估、防护训练等需要,提出一种基于高层体系结构/运行支撑架构 (HLA/RTI)的军事工程毁伤与防护仿真体系结构。在阐述仿真系统概念设计的基础上,确立了军事工程毁伤与防护仿真HLA总体架构,提出了系统功能逻辑结构;模型是HLA联邦开发的核心问题,确立了军事工程毁伤与防护仿真模型体系,遵从军事训练信息系统模型框架,设计了军事工程毁伤与防护模型;最后,给出了系统联邦工作流程,遵循联邦时间策略,以UML时序模型说明联邦成员行为设计。     

Algebraic specifications of computable and semicomputable data types

An extensive survey is given of the properties of various specification mechanisms based on initial algebra semantics.     

Polymorphic programming II. An orthogonal tagged high level architecture abstract machine

This paper describes the implementation of a very powerful high level language from the standpoint of those features rarely found in other languages. These are constancy, polymorphism, user-defined types, orthogonal data structures, and field selectors and routines as assignable values. It examines the characteristics of these features in order to show how they are implemented. They greatly influence the architecture of the underlying abstract machine which is described. Finally the paper highlights several important instructions such as those for routine calling and data structure management. It also shows how the list as a data type in a language can be exploited in the implementation of assignment and parameter passing.     

Design of a simulation environment based on software agents and the high level architecture

We present the SSAHLA project, standing for Simulation based on Software Agents and the High Level Architecture. This project aims at designing a simulation environment for training scenarios, using software agents and the High Level Architecture (HLA). Software agents are considered due to their relevant features to simulation, such as autonomy, adaptability, and collaboration. The HLA is considered as a communication middleware between the participants who take part to the training sessions. Each participant is associated with different types of agents that work for him and thus, perform operations on his behalf.     

基于云计算的桥梁安全与健康监测数据中心基础架构及其数据管理技术

桥梁安全监测数据信息以几何级数速度增长,对数据中心海量数据存储、管理提出了智能化、高效率化的要求.分析了桥梁安全与健康监测数据中心的数据管理技术及发展趋势;阐述了基于云计算（Cloud Computing）的数据中心基础架构;深入探讨了关键设备和软件的选型;对基于云计算的桥梁安全监测数据中心的应用前景进行了展望.     

煤矿本质安全风险源识别的高层体系结构仿真方法

针对目前我国煤矿存在的本质安全风险源识别问题,在分析了高层体系结构(HLA)及分布交互仿真(DIS)的特点及应用情况下,提出采用基于HLA的分布交互仿真方法识别煤矿本质安全风险源.研究了煤矿生产系统分布交互仿真系统的设计、结构及实例分析,以HLA为开发标准,对一个简化的煤矿生产系统建立了分布交互仿真实例,通过仿真实验,分析了风险源的成长机理及煤矿事故成因.结论表明,采用分布交互仿真方法识别煤矿风险源是可行的,有利于制定事故应对措施,提高科学管理.     

高能物理事例级数据管理与传输系统的研究

高能物理实验不断的进步与发展产生了PB乃至EB级的数据,这些数据的采集、存储、传输与共享、分析与管理都面临着极大的问题与挑战。为了应对这些挑战,设计和实现了面向事例的数据管理系统,有效解决事例数据处理效率低以及分站点资源利用率低的问题。设计了一个基于Nosql数据库的事例索引系统,通过事例数据特征抽取,选取物理学家最感兴趣的属性作为索引,存储在数据库中,并采用倒排索引技术,提高事例数据检索的效率。针对事例数据进行缓存优化,减少数据转化和存储开销。提出数据跨域传输方案,充分利用网络带宽,降低分站点处理数据的延迟。系统进行了相关验证,实验结果表明,事例级的索引技术能够显著提高事例数据的检索效率,数据传输系统的网络带宽也可以利用到百分之九十以上。     

面向CDN网络的高效海量数据分发机制研究

针对CDN网络中海量数据分发的要求,设计了一种基于CDN服务器P2P服务的高效数据分发机制,通过对分割后的海量数据分别执行P2P数据分发,克服了现有CDN服务器P2P服务不能根据Internet网络带宽和CDN服务器负载动态变化自适应地调整数据分发过程的缺点。仿真结果表明,提出的海量数据分发机制提高了网络带宽波动对数据分发的性能,能够较好地满足实际CDN网络中海量数据分发的需求。     

A specification language and service‐oriented architecture to support distributed data management

In some research analysis organizations, effort is duplicated when disseminating raw information to multiple research groups. Although the various groups work on different problems, many times, the initial raw information used is the same. A solution to this problem is creating a centralized process for storing and disseminating common information using database technologies. In this paper, the requirements that must be met to create this distributed database management architecture are described. To support these requirements, a specification language, Specialized Format Markup Language (SFML), and supporting service‐oriented architecture, Specialized Format Generation (SFG), are introduced. These implementations and technologies support the translation of data from relational database formats into user‐specified legacy formats. In addition, this implementation supports the presentation of the resulting data across a Web‐based, distributed medium. SFML and SFG incorporate current technologies such as the eXtensible Markup Language (XML), Java Servlets, the eXtensible Stylesheet Language (XSL), and other relational database approaches. Copyright © 2004 John Wiley & Sons, Ltd.     

A comparison of research data management platforms: architecture,flexible metadata and interoperability

Universal Access in the Information Society - Research data management is rapidly becoming a regular concern for researchers, and institutions need to provide them with platforms to support data...