Engineering mobile agent applications via context-dependent coordination

The design and development of Internet applications requiring dynamic and possibly mobile access to Internet resources can take advantage of an approach based on autonomous mobile agents. However, mobility introduces peculiar issues related to the modeling and management of the agents' coordination activities. This paper introduces context-dependent coordination as a framework for the design and development of Internet applications based on mobile agents, and shows how it can be supported by a proper coordination infrastructure. Context-dependent coordination is centered on the notion of programmable coordination media, as the software abstraction via which an agent in an Internet site can access to local resources and coordinate with local agents. Programmability stems from the fact that the behavior of the media can be fully configured to influence agents' coordination activities. This enables local administrators to configure coordination media so as to enact site-dependent coordination policies, and mobile agents to configure the accessed coordination media to obtain an application-dependent behavior of the media themselves. Several application examples shows that exploiting context-dependent coordination promotes a clear separation of concerns in design and development, and can make applications more modular and easier to be maintained. The MARS system is assumed as an exemplar coordination infrastructure to clarify the concepts expressed and to show their actual implementation.     

基于文摘的信息检索模型

基于文摘的检索模型是基于一个假设。即出现在文摘中的词要比未出现在文摘中的词更能表达文章的主题,因此对检索贡献更大.提出了两个基于文摘的语言检索模型,一个是用文摘模型代替文档模型直接检索文件(SQL),另一个是用文摘模型平滑文档模型(SBDM).在TREC数据集上的实验表明,该模型能够提高检索的性能.其中,SBDM的性能一致接近或优于传统的标准文档查询相似模型.有两个方面的贡献,一方面提出了面向检索的文摘抽取方法并考察了这些文摘方法对检索性能的影响;另一方面提出了新的检索模型,即基于文摘的检索模型.     

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.     

基于上下文的深度语义句子检索模型

传统的信息检索的研究多集中在文档级的检索场景中,然而,句子级的检索在如移动应用以及信息需求更加明确的检索场景下具有非常重要的意义。在句子级的检索场景下,我们认为句子的上下文能够提供更加丰富的语义信息来支撑句子与查询的匹配,基于此,该文提出了一个基于句子上下文的深度语义句子检索模型(context-aware deep sentence matching model, CDSMM)。具体的,我们使用双向循环神经网络来建模句子内部以及句子上下文的语义信息,基于句子和查询的语义信息得到它们的匹配程度,在WebAP句子检索数据集上的实验表明,我们的模型性能显著地优于其他的方法,并取得了目前最好的效果。     

MAP: Design and implementation of a mobile agents' platform

The recent development of telecommunication networks has contributed to the success of applications such as information retrieval and electronic commerce, as well as all the services that take advantage of communication in distributed systems. In this area, the emerging technology of mobile agents aroused considerable interest. Mobile agents are applications that can move through the network for carrying out a given task on behalf of the user. In this work we present a platform called MAP (Mobile Agents Platform) for the development and the management of mobile agents. The language used both for developing the platform and for carrying out the agents is Java. The platform gives the user all the basic tools needed for creating some applications based on the use of agents. It enables us to create, run, suspend, resume, deactivate, reactivate local agents, to stop their execution, to make them communicate each other and migrate.     

移动主体异构资源互操作框架

随着Internet的发展,如何实现异构资源之间的互操作成为当前研究热点。要适应Internet这种开放、动态的环境,需要软件具有组件化、开放化、自主化等特点,而面向主体的软件开发方式则能满足这些需要。提出了一种基于移动主体（Mobile Agent）的异构资源互操作框架,用以实现异构数据源的整合,为用户提供统一信息检索服务。该框架为一多主体系统（Multi-Agent System）,为了实现主体间的通信和协作,设计了一种基于通用领域本体模型的主体通信机制。此外描述了该框架中移动主体的工作机制。     

Sensory—motor coordination: The metaphor and beyond

Any agent in the real world has to be able to make distinctions between different types of objects, i.e. it must have the competence of categorization. In mobile agents, there is a large variation in proximal sensory stimulation originating from the same object. Therefore, categorization behavior is hard to achieve, and the successes in the past in solving this problem have been limited. In this paper it is proposed that the problem of categorization in the real world is significantly simplified if it is viewed as one of sensory—motor coordination, rather than one of information processing happening “on the input side”. A series of models are presented to illustrate the approach. It is concluded that we should consider replacing the metaphor of information processing for intelligent systems by the one of sensory-motor coordination. However, the principle of sensory-motor coordination is more than a metaphor. It offers concrete mechanisms for putting agents to work in the real world. These ideas are illustrated with a series of experiments.     

一种基于移动Agent的事务处理模型

本文简要分析了C／S模式下事务处理存在的不足,提出了一种基于移动Agent的事务处理模型。该模型一方面满足了事务处理的ACID即原子性、一致性、隔离性和持久性四个方面的要求;另一方面,应用移动Agent部分克服了事务对客户机、服务器及网络环境的依赖。     

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。     

An Internetware Based Approach to Building Web Page Integration Applications for Mobile Devices

Mobile devices are more and more popular in recent years. As a result, there''re huge requests of mobile applications, especially those integrated with multiple information. However, on one hand, most of the mobile applications at present just contain some certain kinds of information and they cannot adapt to the rapid change of users'' requirements, either. On the other hand, to build these applications, it''s usually time consuming and there are not enough resource components with programmable interfaces. In this paper, we propose an approach based on Internerware to building web page integration applications for mobile device. We introduce a framework that provides abundant internet-programmable interfaces, a flexible integration mechanism to meet the users'' rapid changing requirements and a reliable mechanism that guarantees the quality of the referred resources effectively. With this framework, we can rapidly build an application that integrates all the information according to users'' requirement.     

Personal assistants

Already there are simple personal agents to help with some of our shopping. There are agents to track stocks in our portfolios, advise us on how to use particular software products, and arrange meetings within corporate workgroups. However, none of these agents takes more than one aspect of our activities into account, nor do they adapt easily to our preferences. Personal assistants, on the other hand, are agents that can represent individuals on the Web. They help users in their day-to-day activities, especially those involving information retrieval, negotiation, or coordination. A personal assistant might schedule a meeting and then, based on the meeting location, find the nearest babysitting service or the ATM with the lowest transaction fee. The paper discusses the interaction framework, negotiation, profiles and standards     

Generation of augmented video sequences combining behavioral animation and multi‐object tracking

In this paper we present a novel approach to generate augmented video sequences in real‐time, involving interactions between virtual and real agents in real scenarios. On the one hand, real agent motion is estimated by means of a multi‐object tracking algorithm, which determines real objects' position over the scenario for each time step. On the other hand, virtual agents are provided with behavior models considering their interaction with the environment and with other agents. The resulting framework allows to generate video sequences involving behavior‐based virtual agents that react to real agent behavior and has applications in education, simulation, and in the game and movie industries. We show the performance of the proposed approach in an indoor and outdoor scenario simulating human and vehicle agents. Copyright © 2009 John Wiley & Sons, Ltd.     

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     

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.     

Wolves, bees, and football: Enhancing coordination in sociotechnological problem solving systems through the study of human and animal groups

This paper describes how sociotechnological systems comprising human and technological agents can be considered problem solving systems. Problem solving systems typically comprise many agents, each characterized by at least partial autonomy. A challenge for problem solving systems is to coordinate system agent operations during problem solving. This paper explores how competence models of human–human and animal–animal coordination might be used to inform the design of problem solving systems so that the potential for agent coordination is enhanced. System design principles are identified based on a review of competent coordination in human groups, such as work and sport teams, and animal groups, such wolf packs and bee colonies. These principles are then discussed in relation to agent coordination in the domains of E-Science, future combat systems, and medicine, which typify real-world environments comprising problem solving systems.     

Modeling the Exogenous Coordination of Mobile Channel-based Systems with Petri Nets

In this paper, we discuss how to model systems that communicate through and are coordinated by mobile channels. Mainly, we focus on modeling the exogenous coordination behavior imposed by these channels. We use Petri Nets as our modeling language, for they provide a graphically and mathematically founded modeling formalism. We give Petri Nets for a set of mobile channel types. This allows us to construct models of applications, by taking the Petri Net of each component and each mobile channel, and composing them together. For this purpose, we define a special Petri Net composition function. We also discuss analysis and simulation of these models and their exogenous coordination behavior.     

Hayeks Katallaxie — Ein zukunftsweisendes Konzept für die Wirtschaftsinformatik?

The mobile and increasingly ubiquitous use of information technology leads to more dynamic, constantly self-reconfiguring networks. Their services are available anytime and anywhere; as software agents, they can make local, context-aware decisions. F. A. von Hayek developed a theory for economic coordination based on individual decision making. This paper presents the explanation concepts of economic self-organisation as at least one option for the design of decentralized coordination of information systems consisting of autonomous software agents with limited information processing capacity and incomplete information. Experiments using a multi-agent system show that a targeted change of this basic rule set directly influences the behaviour of the individual elements and indirectly the behaviour of the overall system.     

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.     

GeoFairy: Towards a one-stop and location based Service for Geospatial Information Retrieval

It is still a great challenge to efficiently deliver dynamic and heterogeneous Earth observation (EO) information to users based on their real time locations. However, the rapidly evolving techniques create a chance to meet the challenge. This paper proposes a framework to realize a one-stop and location based service (LBS) for geospatial information (GI) retrieval on mobile platforms. The framework originally integrates a number of state-of-the-art techniques with geospatial data resources and let them cooperate together to provide a robust and highly available LBS. Cloud platform is used to deploy the server module. A location enabled load balancing algorithm is presented to balance the cloud instance VMs on behalf of LBS. A system named GeoFairy is implemented. It provides a one-stop service for gathering and delivering twelve kinds of GI on real time locations. Two Apps are built for the major mobile ecosystems: iOS and Android. Many tests, including a stress test, have been made via a number of mobile devices at various locations. The results demonstrate that GeoFairy is capable of one-stop delivering real-time GI to users and significantly reducing costs on information searching and retrieving. This feature is very helpful in many scenarios such as disaster responding and military actions. This research paves a way on both theoretical and practical aspects for researchers and developers to realize operational mobile applications for one stop and location based GI retrieval.