分布式实时系统面向方面的QoS监控模型

分布式实时系统是一个非常重要且资源有限的系统,系统资源的调配策略很大程度上决定了系统是否能满足实时性要求。要制定资源调配策略,首先要标识出实时系统中的各种资源,建立起资源模型。面向方面是一种全新的编程思想,它和面向对象方法结合解决了传统软件开发方法中的一些问题。文章结合面向方面技术,把QoS监控作为一个关注点,通过UML的扩展机制描述了分布式实时系统中资源模型的面向方面的QoS监控模型。     

一个基于嵌入式实时操作系统内核的状态

在嵌入式实时系统的研发过程中,传统的交叉调试技术无法全面了解系统的实时运行状态.更为严重的是,它会破坏运行任务的实时性.本文在嵌入式交叉调试器研究的基础上提出并实现了一种基于嵌入式实时内核的系统状态监视器,它不但能够获取开发者所需的系统状态数据,而且能够有效保证运行任务的实时性.     

嵌入式软件仿真测试平台实时数据处理研究

实时数据处理在嵌入式软件仿真测试平台中起着要目标和实时数据处理的要求,提出了一种实时数据处理体系的逻辑模型,并对实时数据管理、事务调度、实时接口映射机制等关键技术进行了深入探讨.     

基于策略模式的信息隐藏处理的软构件

从软件复用的角度出发,介绍了一种信息隐藏的软件构造形式,并给出了该软构件在一种信息隐藏研究中的应用,实现了一种信息加密和分析的实验平台。根据软件的复用性,该软构件也可以作为独立的软件元素,应用到其他的信息隐藏处理系统中,为传递秘密信息软构件的生成提供了方便,提高了软件开发的效率和成熟度。     

实时程序设计方法的发展趋势

本文概述了目前实时程序设计方法学的两个基本方面:实时程序设计语言和实时程序的规范说明及形式化验证。讨论了实时程序设计的基本特点和与一般程序设计的不同之处。程序层次的实时性包括静态的时间限制表达和动态的时间限制维护.程序规范层次的实时性包括建立规范说明模型和形式化证明。     

ActiveX技术在工控组态软件中的应用

为了增强工控组态软件的功能,开发引入了ActiveX技术,并结合数据库技术,计算机网络技术,形成一种基于浏览器的实时数据监控系统,同时在ActiveX控件的开发中采用了一种全新的方法一位图法,大大减少了编写程序的工作量,提高了开发的质量和效率。以广州钛白粉厂生产过程实时监控系统的项目开发为实例,介绍了系统的设计,Active控件的开发和应用。     

一种基于ATCA平台下的IPMI监视软件

ATCA（高级电信计算架构）有着优秀的机架管理功能,这种功能基于IPMI（智能平台管理接口）规范实现。设计了一种ATCA平台下的对ShMC（机架管理控制器）和刀片上IPMC（智能平台管理控制器）模块间的IPMI报文交互进行监控的软件,从而能够对刀片上的FRU的整个热插拔过程进行分析。该软件是用VC＋＋实现的,运行结果表明,它能够准确地显示IPMI报文的相关信息．令操作人员能够对ATCA单板的运行状态进行有效分析。     

一种基于ATCA平台下的IPMI监视软件

ATCA(高级电信计算架构)有着优秀的机架管理功能,这种功能基于IPMI(智能平台管理接口)规范实现.设计了一种ATCA平台下的对ShMC(机架管理控制器)和刀片上IPMC(能平台管理控制器)模块间的IPMI报文交互进行监控的软件,从而能够对刀片上的FRU的整个热插拔过程进行分析.该软件是用VC 实现的,运行结果表明,它能够准确地显示IPMI报文的相关信息,令操作人员能够对ATCA单板的运行状态进行有效分析.     

A model for software reuse

Software reusability is widely believed to be a key to help overcome the ongoing software crisis by improving software productivity and quality. New computer technology and the demands of an advancing society require new and more complicated software. It is unrealistic to expect that every software system can be developed solely reusing existing software; however, software reusability has proven to be a way of enhancing software productivity and quality in different organizations. It is also believed that reuse of code segments alone does not significantly reduce software development effort.By creating reuse support information while software is being developed (when the software is best known to software developers), the reuse effort for both software development and maintenance can be potentially reduced.In this paper, five types of RSI are presented: Semantic Web, Horizontal Web, Vertical Web, Syntactic Web, and Alternative Web. We collectively call these five webs a Quintet Web. The Semantic Web enables software developers to locate a software segment. The Horizontal Web provides a means to reuse a block of soflware along with other types of software from other phases of a development process. The inter-phase integration of software can be performed through this Web. The Vertical Web identifies the vertical relationship of a software block to its operational environment. The Syntactic Web locates all statements in which a variable is used. The Alternative Web provides alternative software blocks that perform an identical operation.A prototype of the Quintet Web is presented.     

A Model for Updating Real-Time Applications

Updating application software is a common occurrence for modern computing systems. Software updates stem from the need to correct coding errors or to enhance the functionality of an application. Updating an application typically requires taking the current application offline and restarting a new application. This method of updating an application is perfectly acceptable for many general purpose-computing environments. However, in real-time environments that require high availability and have stringent timing constraints, taking a process offline for updates may be unacceptable or pose unnecessary risks. Some examples of these environments include telecommunications, air traffic control, railway control and medical patient monitoring. We present a new method to dynamically update a real-time application without having to take it offline. Our new method, which we call dynamic update for real-time systems, can be used to update real-time applications using rate-monotonic scheduling, while preserving the original deadline guarantees.     

Resource Management Middleware for Dynamic,Dependable Real-Time Systems

Thispaper presents resource management techniques that achieve thequality of service (QoS) requirements of dynamic real-time systemsusing open architectures and commercial off-the-shelf technologies(COTS). Dynamic real-time systems are subject to constant changessuch as a varying external environment, overload of internalsystems, component failure, and evolving operational requirements.Examples of such systems include the emerging generation of computer-based,command and control systems of the U.S. Navy. To enable the engineeringof such systems, we present adaptive resource management middlewaretechniques that achieve the QoS requirements of the system. Themiddleware performs QoS monitoring and failure detection, QoSdiagnosis, and reallocation of resources to adapt the systemto achieve acceptable levels of QoS. Experimental characterizationsof the middleware using a real-time benchmark illustrate itseffectiveness for adapting the system for achieving the desiredreal-time and survivability QoS during overload situations.     

An Approach to Platform Independent Real-Time Programming: (2) Practical Application

In a previously published companion paper a method for extending programming languages with timing constructs was proposed. It was shown that the extension enables the construction of real-time programs that can be proven correct independently of the properties of the machine that is used for their execution. It also yields a strict division of system construction into two phases: (1) a platform-independent programming phase that includes the expression of timing requirements, and (2) an implementation phase where all platform dependencies are addressed. In this second paper the approach is illustrated using an example problem often quoted in the literature: the mine-pump system. The two mentioned phases are described in detail for this example. First, a program is obtained in a systematic way. Then, realizations of the program under various schemes for distribution and scheduling are considered and analyzed. A comparison with other approaches to real-time programming is given.     

Windows应用程序调用MATLAB程序的解决方案

本文提出了一套针对Ｗｉｎｄｏｗｓ应用程序通过ＤＬＬ外部调用ＭＡＴＬＡＢ程序的方案,分析论证了该方案的可行性和实用性,并对其中的关键技术作出了说明。     

A Real-Time Discrete Event System Specification Formalism for Seamless Real-Time Software Development

We present a time domain extension of the hierarchical and modular discrete event specification (DEVS) formalism. This extension is important for establishing a seamless real-time software development framework. Formalisms help describe a system unambiguously. If formal models are implemented without any consistent frameworks, however, it is hard to guarantee that there is no semantic gap between models and codes. Real-Time DEVS, named RTDEVS, is an extension of DEVS that can be characterized in three perspectives: the real time execution of models, the addition of time interval functions, and the activity specification for each state. After analyzing a system, the framework based on RTDEVS helps to expand each model of the system for executing in a real-time environment. In order to support the RTDEVS formalism, we propose abstract executive concepts based on the abstract simulator concepts of the DEVS formalism. Also, we implement an RTDEVS execution engine, named DEVS Executive, which runs on real-time Mach.     

基于构件技术的卫星地球站站控系统的设计模型

本文在分析已有卫星地球站站控系统模型优缺点的基础上,立足于站控系统的开放性、集成性和效率,运用基于构件的软件工程技术,提出一种层次清晰、接口规范、联系简洁、易于扩充的站控系统构件模型,并详细分析了模型中各构件的功能和构件间的通讯。该系统模型便于实现结构灵活、开放性强的实用系统。同时,构件也为易于实现软件
件复用。     

IMPACT: A System for Building Agent Applications

IMPACT (Interactive Maryland Platform for Agents Collaborating Together) provides a platform and environment for agent and software interoperability being developed as a joint, multinational effort with participants from the University of Maryland, the Technische Universität Wien, Bar-Ilan University, the University of Koblenz, and the Universita di Torino. Here, we describe the overall architecture of the IMPACT system, and outline how this architecture (i) allows agents to be developed either from scratch, or by extending legacy code-bases, (ii) allows agents to interact with one another, (iii) allows agents to have a variety of capabilities (reactive, autonomous, intelligent, mobile, replicating) and behaviors, and (iv) how IMPACT provides a variety of infrastructural services that may be used by agents to interact with one another.     

A Rigorous Architectural Approach to Adaptive Software Engineering

The engineering of distributed adaptive software is a complex task which requires a rigorous approach. Software architectural (structural) concepts and principles are highly beneficial in specifying, designing, analysing, constructing and evolving distributed software. A rigorous architectural approach dictates formalisms and techniques that are compositional, components that are context independent and systems that can be constructed and evolved incrementally. This paper overviews some of the underlying reasons for adopting an architectural approach, including a brief “rational history” of our research work, and indicates how an architectural model can potentially facilitate the provision of self-managed adaptive software system. Much of the research has been supported by the Engineering and Physical Sciences Research Council and is currently partly supported by EPSRC Platform grant AEDUS 2 and a DTC grant.     

A distributed development environment for embedded software

The HAGAR project is building a high-performance disk controller. It is an embedded system for which many hundreds of thousands of lines of embedded software will have to be developed concurrently with the development of the hardware. We found existing methods for embedded software development, such as simulation and remote cross development, to be inadequate for us. To meet our special needs, we developed a distributed development environment that combines and extends the capabilities of existing methods while fixing their drawbacks. Our environment is based on a processor-pool architecture, in which multiple hardware sets are pooled and managed systematically. It supports embedded software development for many programmers at different sites. It allows for the emulation of non-existing hardware adaptor cards and for the integration of embedded software testing with hardware simulation. The environment provides a single system image, hiding many hardware and configuration details from its users. From the perspective of the programmers, our environment makes developing embedded software for special hardware systems as easy as developing application programs for a UNIX workstation.