Context-aware middleware for resource management in the wireless Internet

The provisioning of Web services over the wireless Internet introduces novel challenging issues for service design and implementation: from user/terminal mobility during service execution, to wide heterogeneity of portable access devices and unpredictable modifications in accessible resources. In this scenario, there are frequent provision-time changes in the context, defined as the logical set of accessible resources depending on client location, access terminal capabilities, and system/service management policies. The development of context-dependent services requires novel middlewares with full context visibility. We propose a middleware for context-aware resource management, called CARMEN, capable of supporting the automatic reconfiguration of wireless Internet services in response to context changes without any intervention on the service logic. CARMEN determines the context on the basis of metadata, which include declarative management policies and profiles for user preferences, terminal capabilities, and resource characteristics. In addition, CARMEN exploits the mobile agent technology to implement mobile middleware components that follow the provision-time movement of clients to support locally their customized service access. The proposed middleware shows how metadata and mobile agents can favor component reusability and automatic service reconfiguration, by reducing the development/ deployment complexity.     

移动代理应用中上下文相关的客观协调

移动代理之间需要进行交互合作才能完成系统任务,每个移动代理也需要与它运行所在的移动代理环境进行交互。文章提出了一种在移动代理应用系统中的上下文相关的客观协调模型,适合移动代理系统中移动代理之间的交互和移动代理与移动代理环境之间的交互,它把全局的耦合交互转变成本地独立的元组空间交互,用可编程的元组空间解决由代理移动引起的上下文相关协调问题,而且环境相关的协调策略和应用相关的协调策略可以集成到可编程的元组空间中。     

Mobile Agent Coordination for Distributed Network Management

Mobile agents are a promising technology to face the problems raised by the increasing complexity and size of today's networks. In particular, in the area of network management, mobile agents can lead to a fully distributed paradigm to overcome the limits of traditional centralized approaches. A basic requirement for the management of a complex network is the definition of high-level and flexible models to coordinate the accesses to the resources—data and services—provided by the network nodes. On this basis, this paper describes the MARS coordination architecture for mobile agents. MARS is based on the definition of programmable tuple spaces associated with the network nodes: mobile agents can access the local resources and services via the tuple space, thus adopting a standard and high-level interface. The network administrator—via mobile agents—can dynamically program the behavior of the tuple space in reaction to the agents' access to the tuple space, thus leading to a flexible network model. Several examples show the effectiveness of the MARS approach in supporting network management activities.     

Coordination for Internet Application Development

The adoption of a powerful and expressive coordination model represents a key-point for the effective design and development of Internet applications. In this paper, we present the TuCSoN coordination model for Internet applications based on network-aware and mobile agents, and show how the adoption of TuCSoN can positively benefit the design and development of such applications, firstly in general terms, then via a TuCSoN-coordinated sample application. This is achieved by providing for an Internet interaction space made up of a multiplicity of independently programmable communication abstractions, called tuple centres, whose behaviour can be defined so as to embody the laws of coordination.     

Secure Sharing of Tuple Spaces in Ad Hoc Settings

Security is emerging as a growing concern throughout the distributed computing community. Typical solutions entail specialized infrastructure support for authentication, encryption and access control. Mobile applications executing over ad hoc wireless networks present designers with a rather distinct set of security requirements. A totally open setting and limited resources call for lightweight and highly decentralized security solutions. In this paper we propose an approach that relies on extending an existing coordination middleware for mobility (Lime). The need to continue to offer a very simple model of coordination that assures rapid software development led to limiting extensions solely to password protected tuple spaces and per tuple access control. Password distribution and security are relegated to the application realm. Host level security is ensured by the middleware design and relies on standard support provided by the Java system. Secure interactions among agents across hosts are accomplished by careful exploitation of the interceptor pattern and the use of standard encryption. The paper explains the design strategy used to add security support in Lime and its implications for the development of mobile applications over ad hoc networks.     

Supporting virtual enterprise systems using agent coordination

Open environments like the Internet or corporate intranets enable a large number of interested enterprises to access, filter, process and present information on an as-needed basis. These environments support modern applications, such as virtual enterprises and interorganisational workflow management systems, which involve a number of heterogeneous resources, services and processes. However, any execution of a virtual enterprise system would yield to disjoining and error-prone behaviour without appropriate techniques to coordinate the various business processes. This paper reports on the design and implementation of a flexible agent-based framework for supporting the coordination of virtual enterprises and workflow management systems. The paper also shows how an agent coordination infrastructure, which is explained by social constraints, can impact on the engineering of highly dynamic virtual enterprises and workflow management systems by presenting a simple case study.     

Reflections on the Nature of Multi-Agent Coordination and Its Implications for an Agent Architecture

The development of enabling infrastructure for the next generation of multi-agent systems consisting of large numbers of agents and operating in open environments is one of the key challenges for the multi-agent community.Current infrastructure support does not materially assist in the development of sophisticated agent coordination strategies. It is the need for and the development of such a high-level support structure that will be the focus of this paper. A domain-independent (generic) agent architecture is proposed that wraps around an agent's problem-solving component in order to make problem solving responsive to real-time constraints, available network resources, and the need to coordinate—both in the large and small—with problem-solving activities of other agents. This architecture contains five components, local agent scheduling, multi-agent coordination, organizational design, detection and diagnosis, and on-line learning, that are designed to interact so that a range of different situation-specific coordination strategies can be implemented and adapted as the situation evolves. The presentation of this architecture is followed by a more detailed discussion on the interaction among these components and the research questions that need to be answered to understand the appropriateness of this architecture for the next generation of multi-agent systems.     

Teaching and learning in the wireless classroom

Wireless networks now support Web browsing, e-mail, real-time chat, and access to remote computing resources. With the increasing use of small portable computers, this emerging communications infrastructure will enable many new Internet applications. Two innovative projects at the University of North Carolina at Wilmington are currently exploring how educators can use portable handheld computers with wireless Internet access to improve teaching and learning in both local and wide area network environments     

Mobile-agent coordination models for Internet applications

Internet applications face challenges that mobile agents and the adoption of enhanced coordination models may overcome. Each year more applications shift from intranets to the Internet, and Internet-oriented applications become more popular. New design and programming paradigms call help harness the Web's potential. Traditional distributed applications assign a set of processes to a given execution environment that, acting as local-resource managers, cooperating a network-unaware fashion. In contrast, the mobile-agent paradigm defines applications as consisting of network-aware entities-agents-which can exhibit mobility by actively changing their execution environment, transferring themselves during execution. The authors propose a taxonomy of possible coordination models for mobile-agent applications, then use their taxonomy to survey and analyze resent mobile-agent coordination proposals. Their case study, which focuses on a Web-based information-retrieval application, helps show that the mobility of application components and the distribution area's breadth can create coordination problems different from those encountered in traditional distributed applications     

Mobile digcovery: discovering and interacting with the world through the Internet of things

The application of Internet-enabled devices in the real world for the development of Smart Cities, environmental monitoring, bus tracking, and parking requires scalability, extensibility, and integration of emerging resources to reach a suitable ecosystem for data acquisition and interaction with citizens. Internet of things needs to offer efficient support for global communications and access to services and information. It needs to enable homogeneous and seamless machine-to-machine communication for different solutions and applications. This work presents an homogeneous and suitable mechanism for global resource discovery, device access for deployed smart objects in different scenarios, and sensors and devices from end users (participative sensing). The integration of legacy and sensors already available from smart buildings and smart objects is presented. For this purpose, a resolution infrastructure called “digcovery” is defined for maximizing efficiency and sustainability of deployments. Digcovery architecture offers the framework to allow users to register/include their own sensors into a common infrastructure and access/discover the available resources through mobile digcovery. Mobile digcovery exploits the context-awareness, geo-location, and identification technologies available in mobile platforms such as smartphones to discover, interact, and access the resources through its ElasticSearch engine.     

The status and future of 802.11-based WLANs

The main attraction of WLANs is their flexibility. They can extend access to local area networks, such as corporate intranets, as well as support broadband access to the Internet - particularly at "hot spots," public venues where people tend to gather. WLANs can provide quick, easy wireless connectivity to computers, machinery, or systems in a local environment where a fixed communications infrastructure does not exist or where such access is not permitted. These hosts can be stationary, handheld, or even mounted on a moving vehicle. Bandwidth considerations have thus far been secondary in WLAN design and implementation: the original 802.11 standard allowed a maximum channel bit rate of only 2 megabits per second, while the current 802.11 b standard supports an 11 Mbps maximum rate. However, the widespread deployment of 802.11a and 802.11g standards, which allow a bit rate of up to 54 Mbps, will pave the way for new types of mobile applications, including m-commerce transactions and location-based services.     

Kontextbasierte Kooperation für mobile Geschäftsanwendungen

Realistic requirements of mobile business applications often exceed the capabilities of their respective local environments. In order to overcome such restrictions of specific mobile devices, services, and resources, this contribution introduces the concept of context-based cooperation. It is based on mobile processes which enable applications to cross boundaries of individual systems and thereby allow combining both mobile and stationary resources in order to realize highly dynamic individual applications. This contribution presents an approach for realizing context-based cooperation built upon on a respective context management infrastructure and execution environment. It also identifies specific requirements and proposes related enhancements for mobile business applications.     

XACML的移动应用安全策略及测试方法

随着移动互联网技术的发展,具有计算功能的移动终端被大量部署,并在大量移动应用的支撑下完成各项任务;愈来愈多的企业允许员工带着他们的个人设备进入工作环境(BYOD模式)。但不同的人员有不同的角色,不同的资源有不同的访问权限,敏感资源一旦被泄露,将可能给企业带来重大的损失。因此,要想全面支持BYOD,保障数据和系统的安全,需要相应移动应用对敏感资源的访问控制进行明确的规定,并在移动应用运行过程中执行。XACML是访问控制策略的统一描述语言,但目前还未见其对移动应用和BYOD的支持。提出基于XACML语言描述移动应用的访问控制策略,研究XACML访问控制策略的测试方法;在此基础上,面向BYOD,针对Android平台上的项目管理APP进行了实例研究,结果展示了所提方法的有效性。     

Rethinking QR code: analog portal to digital world

In this paper, we are introducing a new view for the applications and the activities using QR codes to access the information for the objects existing in everyday human environment. This view emphasizes the possibility of the QR codes as an Analog Portal—an ambient media gate to the Digital World, because it shows the new way of access to the Internet and may be able to change the culture of retrieving information when the QR code infrastructure becomes mature.     

AgletBlackboard：Aglets系统协同机制的扩充

随着Internet的不断发展，移动Agent技术的应用越来越广泛。实际的应用通常需要由多个移动Agent共同来完成任务，如何组织与协调移动Agent之间的行动带来了对分布式环境中移动Agent之间协同的研究。本文介绍了移动Agent的四种协同模式，并针对Aglets系统中Aglet之间通过直接协同存在的不足．设计实现了基于黑板协同模式的AgletBlackboard，进一步提高了Aglets系统的功能。     

Adapting Web content to mobile user agents

In this article, we describe an adaptation proxy we developed as a part of a Kontti research project at VTT Information Technology that lets mobile users access Web content that's not directly targeted to mobile user agents. More and more content is now available on the Internet, and there's a growing need for mobile users to be able to access it. Thus the authors describe the adaptation proxy, which lets mobile users access Web content that's not directly targeted to user agents of mobile devices. The adaptation proxy can adapt Extensible Hypertext Markup Language (XHTML) documents into XHTML mobile profile (XHTML MP) and Wireless Markup Language (WML), and can perform media adaptation. At the system's core is an adaptation framework to which new source and target XML languages can be introduced with relatively little effort.     

Coordinating Mobile Agents by the XML-Based Tuple Space

This paper presents Xspace,a programmable coordination paradigm for Internet applications based on mobile agents.The Xspace system fully exploits the advantages of the XML language and Linda-like coordination.It supports XML documents as tuple fields and multiple matching routines implementing different relations among XML documents,including those given by XML query languages,The Xspace uses Java as the implementation language;it is based on object-oriented XMLized tuple spaces to implement a portable and programmable coordination paradigm for mobile agents.The dsign and implementation procedures of Xspace are described in this paper,Experiment and performance evaluation are also made.Finally,some conclusinos and remarks are given.     

An agent infrastructure for on-demand processing of remote-sensing archives

Advances in data collection techniques and database technologies, such as remote sensing and satellite telemetry, have led to the collection of huge amounts of data distributed among large databases and heterogeneous remote sites. Intelligent and automatic processing of the distributed data and efficiently supporting scientific collaboration between both professional and casual users is a highly demanding task. It is also particularly challenging when the system must cope with active data that is processed on-demand. These requirements have generated an urgent need for more advanced software infrastructure to create, maintain, evolve, and federate these active digital libraries of scientific data. Traditional models of distributed computing are inadequate to support such complex applications. As part of the ongoing Synthetic Aperture Radar Atlas (SARA) Digital Library project, the research presented here proposes a collaborating mobile agent approach to on-demand processing of remote sensing data. The approach, which is based on autonomous data processing and enables different image analysis algorithms to be wrapped as mobile agents, is expected to be an improvement over the static CGI-based interface and inefficient information discovery that are currently used by SARA. We discuss the agent-based infrastructure we have developed. The SARA system allows users to dispatch their compute-intensive jobs as mobile agents. Since the agents can be programmed to satisfy their specific goals, even if they move and lose contact with their creators they can survive intermittent or unreliable network connections. During their lifetime, the agents can also move themselves autonomously from one server to another for load balancing, and to enhance data locality and fault tolerance. The SARA system relies on XML to support agent communications on clusters of servers. Although the examples presented are based mainly on the SARA system, the proposed techniques are applicable to other active archives. In particular, we believe the proposed agent design can be used to dynamically configure distributed parallel computing resources and automatically integrate data analysis in remote sensing systems.     

油气工程师助手（PDA）移动代理平台的研究与实现

移动计算被认为是对未来最有影响的四大技术方向之一,它使得计算机或其他信息设备在没有与固定的物理连接设备相连的情况下能够传输数据,将有用、准确、及时的信息能提供给在任何时间、任何地点需要它的任何用户。而移动代理是唯一能满足移动计算全部要求的体系框架。为了更好地支持便携式设备上Microsoft的WinCE平台的移动计算,设计了一个基于C＋＋的支持Windows操作系统的企业用移动代理系统——WinMAS,首次提出了基于编译性语言上的新移动代理迁移机制——利用RPC的序列化和远线程插入机制。     

物联网环境下多智能体决策信息支持技术

随着物联网技术的不断发展,传感器网络得到了广泛的应用并成为信息技术领域重要的基础设施。尤其是传感网络提供的实时感知信息,为许多智能应用提供了充分的信息支持和必要的决策依据。然而,由于智能应用的实时感知信息需求通常无法转化为简单的查询请求与传感器底层查询接口准确匹配,因此,基于物联网的智能决策常常无法准确获取到决策相关的实时信息。针对此问题,提出一个基于语义覆盖网的物联网信息资源描述、推理和应用模型,并以多智能体系统决策支持为应用基础,研究了新型物联网环境下的多智能体决策信息支持技术。该技术以基于多智能体系统的团队导向规划的任务分解方法为核心,将复杂任务分解为若干简单子任务,并基于本体推理方法把子任务执行时需要的决策信息转化为精确、完备的传感器信息查询,从而实现从物联网中准确定位具体的传感器并获取相应感知信息的实时决策信息支持机制。