基于Agent的网构软件构件模型及其实现

网构软件代表了Internet环境下的一种新型的软件形态,但仍然面临着外部环境显式化、软件实体主体化、运行机制自适应等问题.从构件的角度出发,提出了EBDI(electronic business document exchange)结构以表示能够根据环境变化实施自主行为的构件,利用动态绑定关系解释了构件的自适应演化特征.根据形式化的Role模型,描述了构件的运行状态、自主运行及自适应演化运行机制.开发了DAgent-Internetware原型作为网构软件的支撑平台,支持以DAgent为构件的网构软件从设计到实现、部署、运行、演化等一系列流程.     

一种普适计算环境下自适应中间件

普适计算环境固有的内在复杂性对当前的基础软件提出了新的挑战,迫切需要一种具有感知和自适应能力的中间件.提出了一个由接口、框架和情境元模型组成的自适应中间件,给出了在CAR构件平台上的设计与实现.为获取构件信息和对外提供服务,接口元模型支持同步和异步接口.情境元模型在构件对象内建模情境信息,计算实体间以基于异步事件通知方式交互.框架元模型分类和管理构件,随着运行时计算环境的变化动态改变中间件的结构和行为.软件实体感知环境的变化,实体间以松耦合的方式交互,动态改变自身的结构和行为,满足普适计算环境下的动态自适应需求.     

基于Agent的自主构件模型设计与评估

为适应复杂环境和业务需求的变化,自适应软件开发要求为系统及其构成成分提供新的抽象和建模手段。自主构件能够感知并依据环境的变化自动地做出决策。采用自主构件开发复杂软件系统的主要目的是有效降低软件开发和维护的复杂性。在分析自适应软件实体功能和特征的基础上,提出一种基于智能体(Agent)的自主构件模型,该自主构件模型能动态感知环境的变化,合理封装自适应逻辑,依据策略规则进行决策,并根据目标导向,自动规划执行行为的序列。评估结果表明,该模型为建模与开发复杂自适应化软件提供了有效的底层支持。     

面向网构软件的构件自适应机制研究*

结合软件agent技术,从构件角度出发,通过对传统构件进行包装,加入行为规则驱动和行为推导两大机制,提出了一种能够在运行时实时适应用户需求变化和运行环境变化的自适应构件。在自适应构件的运行和支撑方面,实现了一个可动态定制自适应构件行为规则的工具,改进了现有的构件支撑平台使得能满足自适应构件的运行需求;最后通过一个例子说明了自适应构件的设计、实现、运行和演化等一系列工作流程。初步实践表明,上述机制和整套框架为开发具有自适应性的网构软件提供了有效支持。     

一种面向自适应软件系统的体系结构描述语言*

从构件角度出发,结合软件agent技术,提出一种能表示根据需求和环境的变化实施自主行为的E-BDI构件模型。基于高阶多型π演算理论,在现有的动态体系结构描述语言D-ADL基础上,提出一种能从运行时角度描述自适应构件的动态行为的体系结构描述语言SOS-ADL。利用SOS-ADL形式化描述E-BDI结构的自适应构件行为,使构件能根据变化的环境和需求,自主推导自身的行为,达到实现软件自适应的目的。案例说明了面向自适应软件系统的体系结构描述语言SOS-ADL的应用。     

一种可定制的自主构件运行支撑框架

描述了一种动态、可定制的构件自主化的实现手段及运行平台,试图通过对实现自主构件的方法和手段的探索,为开发具有自主性的基于Internet的软件系统提供一定的实践基础和经验.在实现自主构件时,采取了改装已有普通构件的方式,将软件Agent技术和构件技术结合起来,通过为构件定制行为规则和规划来控制和调度构件的行为,使得构件能够根据环境的状态调整自己的行为.同时,通过集成可以解释和执行声明式规则的规则引擎,使得可以在不修改构件源代码和重新部署构件的情况下,动态定制和实现构件的自主性行为能力.     

自适应系统软件传感器设计与实现

随着Internet的普及应用,越来越多的软件系统运行在开放的环境中,需要感知和适应环境的变化.如何支持这类复杂软件系统的开发和运行已经成为当前软件工程面临的一项重要挑战.针对自适应系统与其驻留环境的交互问题,将自适应系统中的软件实体抽象为自主Agent,提出了自主Agent感知环境变化的软件传感器及其与环境的动态关联思想,给出了软件传感器的设计和实现.不同于已有研究,将软件传感器视为一类特殊的软件Agent.最后通过案例分析展示了上述思想和技术的可行性和有效性.     

一种基于Agent的高可用性网构软件自动构建方法

Internet环境开放、动态的本质,计算实体自身的自主性和独立性以及网络连接的不稳定性等,均对保障软件系统可用性提出了新的要求.提出了一种基于Agent的高可用性软件构造方法.该方法使用Agent建模网络环境中的自主计算实体,在计算实体及其连接方式的可用性未知的情况下,由Agent通过学习,在运行一段时间后自适应地构造出可用性较优的软件系统.实验表明,基于该方法构建的系统能达到较高的可用性,并能在环境发生变化时自适应地调整自身的行为.     

云计算环境下实体的多属性高效率评估策略设计

鉴于当前在云计算的实体信任评估领域所实施的方法策略无法满足云计算环境的动态模糊性,以遗传自适应学习算法为理论基础,在云计算环境下的信任管理过程中,针对动态评估高效率的需求,设计了多属性信任关系的动态评估模型。其可以评估分析信任管理过程实体的多属性问题,同时可以在持续的评估过程中,自主的学习,使其评估分析的执行能力逐渐提升,最终能够满足上文中阐明的高效性与动态性的要求。经过实验分析表明,本文所设计的模型在直接面对实时变化的云计算网络环境实体参数时,其可以自适应的调整评估策略规则,最终克服了云计算环境的动态模糊性,对实体的多个属性进行了综合评估。     

基于体系结构的网构软件演化关键技术研究

随着Internet的发展,网构软件的研究越来越受到人们的重视。研究者在网构软件的自适应演化方面虽然做了许多研究,取得了很多成果,但也有不足之处。针对网构软件的演化,文中提出了一种以主动连接器、规则库、构件选择推理机、构件描述库为核心的体系结构,在构件实体方面采用Web服务技术。在软件结构的基础上研究了规则库的建立过程、研究了推理机的推理算法和构件选择策略,这使得软件运行时能根据上下文环境动态选择调用Web服务构件。     

网构软件中实体发现和排序的TEA方法(英文)

自治软件实体分布在开放、动态和多变的互联网中,它们的协作构成网构软件的基础。动态连接模式是网构软件重要的协作方式。在该模式下,如何选择具有所需质量的软件实体,是一个非常困难的任务。介绍了运行时测试和自动化测试技术,提出网构软件的自动化运行时测试方法。总结网构软件中用于软件实体的发现和排序的解决方法,提出了测试和评估方法TEA。网构软件不知道候选软件实体的质量,通过进行自动化的运行时测试,TEA可以选择具有更高质量的实体。如同网构软件一样,自治软件实体也可以在运行时改变自身结构。通过使用确认断言来评估每次实体调用的结果,TEA可以尽早发现实体变化引起的质量问题。TEA中的软件实体注册机收集每个不同的网构软件反馈的测试和评估结果信息,可以产生按估计质量排序的实体列表。在模拟实验中,TEA产生的有序列表获得最好的评估分数。     

Preface

The vision of ''Internet as a computer'' motivates many technical trends, like pervasive computing, grid computing, service computing and recently, cloud computing, as well as some business trends, like modern service industry, digital economy and smarter planet. These evolutionary changes demand that the software systems which are running on the open and dynamic Internet have to be autonomous, context-sensitive, continuous-reactive, evolutionary, and proactive, and the software entities dispersed on distributed nodes over the Internet will be turned into self-contained, autonomous and adaptive. Thus, like the information Web, i.e. the World Wide Web, these Internet-based software entities will constitute a software Web. That gives birth a new software paradigm. A portmanteau term ''Internetware'' is used to denote the future software-web. An Internetware system will be able to perceive the changes of the open and dynamic environment, respond to the changes, and exhibit the context-aware, adaptive and trustworthy behaviors. The mission of Internetware may challenge many aspects of software technologies, from the operating platforms and the programming models to the engineering approaches. Internetware 2010, the second Asia-Pacific Symposium on Internetware, aims to provide an interactive forum where researchers and professionals from multiple disciplines and domains meet and exchange ideas to explore and address the challenges brought by Internetware. The symposium was held at Suzhou, China, during the 2-4 of Nov, 2010. Thirty three papers were submitted and each of them was reviewed by at least two members of an International Program Committee. Among them, 12 have been accepted (which means an acceptance rate of 36%) for their quality as well as for their interesting terms of discussions for the symposium attendees. This special issue contains 7 revised and substantially extended papers from the 12 based on presentations at the symposium: ......     

基于服务更新的网构软件可靠性模型研究(英文)

网构软件是在开放、动态和多变的Internet环境下软件系统基本形态的一种抽象。这种新的软件系统,它的构建依赖于开放环境中各异构、自治的软件服务实体之间的有效协同。其可靠性不单取决于拥有自主性的软件服务实体本身,还取决于外部环境的动态变化,主要表现为开放环境下服务实体元素的更新,所以传统的软件可靠性的度量模型已不能适应这种新的软件形态。能否在网构软件形态下建立一个好的可靠性度量模型成为其中一个较为核心的问题。文章以服务更新过程中失效数(failurecounts)为基础,将服务更新强度引入Musa-Okumoto(M-O)模型中,作为M-O模型在新的软件形态下的一个推广。最后讨论了网构软件退化的情形和退化条件,为开放环境下网构软件可靠性研究提供一种思路。     

Towards Software Architecture and Mechanisms for Improving Runtime Variability of Internetware System

As an emerging software paradigm, Internetware is proposed to handle openness, dynamism of software systems in the context of Internet, which implies that such software systems typically have runtime variability that can be improved dynamically to handle various or even unexpected changes of requirements and open environment. Though many progresses of Internetware software technologies have been made to support the adaptation, evolution, context-awareness, etc. of Internetware, how to construct Internetware systems with the ability to improve their runtime variability is still a great challenge in the literature of software engineering. In this paper, we propose software architecture and mechanisms for Internetware systems to support the improvement of their runtime variability by combining software variability and autonomic computing techniques. The Internetware system is organized as three levels that are consist of variable autonomic elements and Internetware entities, and architecture of these software entities is defined and discussed respectively. Moreover, we put forward a series of runtime mechanisms based on these levels, including module selection, intermediator and horizontal management, to realize operations upon the variation points and variants in software architectures and thus achieve the improvement of runtime variability. We develop a sample of Personal Data Resource Network to depict the requirements and scenario of improving runtime variability, and further study the case based on our proposed approach to show its effectiveness and applicability.     

Support for situation awareness in trustworthy ubiquitous computing application software

Due to the dynamic and ephemeral nature of ubiquitous computing (ubicomp) environments, it is especially important that the application software in ubicomp environments is trustworthy. In order to have trustworthy application software in ubicomp environments, situation‐awareness (SAW) in the application software is needed to enforce flexible security policies and detect violations of security policies. In this paper, an approach is presented to provide development and runtime support to incorporate SAW in trustworthy ubicomp application software. The development support is to provide SAW requirement specification and automated code generation to achieve SAW in trustworthy ubicomp application software, and the runtime support is for context acquisition, situation analysis and situation‐aware communication. To realize our approach, the improved Reconfigurable Context‐Sensitive Middleware (RCSM) is developed to provide the above development and runtime support. Copyright © 2006 John Wiley & Sons, Ltd.     

Dynamic mapping of cooperating tasks to nodes in a distributed system

Networks of workstations (NOWs) are a low-cost and widespread platform for parallel computing. This paper focuses on the dynamic task-scheduling problem in NOW environments. The aim is to minimize the completion time of parallel programs by distributing cooperating concurrent tasks to homogeneous networked nodes. Cooperation dependencies as well as creation and termination dependencies between tasks are taken into account. An event lattice model is introduced to describe past, actual and future behavior of a parallel program in execution. Based on this model an algorithm is presented to dynamically assign tasks to the nodes of a dedicated distributed system. Crucial for the efficiency of this approach is a top-down construction of all operating system entities involved in distributed resource management, particularly the close cooperation of the compiler and runtime system, which allows the creation of event lattice clippings at runtime.     

面向物联网应用的SoC安全检查架构设计

物联网（IoT）应用的快速发展和软硬件开源化趋势使得IoT设备所面临的硬件安全威胁日益严峻,尤其是利用运行时条件触发的系统级攻击,很难通过传统测试方法进行检测和防御,需要提供运行时安全检查机制。分析IoT系统芯片面临的安全威胁,结合数据加密传输路径中的攻击、任务流和检查内容,设计4条功能完整性安全检查策略,搭建SoC安全策略检查架构并植入运行时触发硬件木马。仿真结果显示,运行时策略检查状态机可以检查出加密核、内存和UART接口的功能完整性问题,并通过发送错误中断信号进行反馈,证明了所设计的系统级安全策略检查架构的正确性与有效性。     

A secure collaboration service for dynamic virtual organizations

Nowadays, various promising paradigms of distributed computing over the Internet, such as Grids, P2P and Clouds, have emerged for resource sharing and collaboration. To enable resources sharing and collaboration across different domains in an open computing environment, virtual organizations (VOs) often need to be established dynamically. However, the dynamic and autonomous characteristics of participating domains pose great challenges to the security of virtual organizations. In this paper, we propose a secure collaboration service, called PEACE-VO, for dynamic virtual organizations management. The federation approach based on role mapping has extensively been used to build virtual organizations over multiple domains. However, there is a serious issue of potential policy conflicts with this approach, which brings a security threat to the participating domains. To address this issue, we first depict concepts of implicit conflicts and explicit conflicts that may exist in virtual organization collaboration policies. Then, we propose a fully distributed algorithm to detect potential policy conflicts. With this algorithm participating domains do not have to disclose their full local privacy policies, and is able to withhold malicious internal attacks. Finally, we present the system architecture of PEACE-VO and design two protocols for VO management and authorization. PEACE-VO services and protocols have successfully been implemented in the CROWN test bed. Comprehensive experimental study demonstrates that our approach is scalable and efficient.