A secure migration process for mobile agents

This article describes a decentralized secure migration process of mobile agents between Mobile‐C agencies. Mobile‐C is an IEEE Foundation for Intelligent Physical Agents (FIPA) standard compliant multi‐agent platform for supporting C/C++ mobile and stationary agents. Mobile‐C is specially designed for mechatronic and factory automation systems where malicious agents may cause physical damage to machinery and personnel. As a mobile agent migrates from one agency to another in an open network, the security concern of mobile agent systems should not be neglected. Security breaches can be minimized considerably if an agency only accepts mobile agents from agencies known and trusted by the system administrator. In Mobile‐C, a strong authentication process is used by sender and receiver agencies to authenticate each other before agent migration. The security framework also aims to guarantee the integrity and confidentiality of the mobile agent while it is in transit. This assures that all agents within an agency framework were introduced to that framework under the supervision and permission of a trusted administrator. The Mobile‐C Security protocol is inspired from the Secure Shell (SSH) protocol, which avoids a single point of failure since it does not rely on a singular remote third party for the security process. In this protocol, both agencies must authenticate each other using public key authentication, before a secure migration process. After successful authentication, an encrypted mobile agent is transferred and its integrity is verified by the receiver agency. This article describes the Mobile‐C secure migration process and presents a comparison study with the SSH protocol. The performance analysis of the secure migration process is performed by comparing the turnaround time of mobile agent with and without security options in a homogeneous environment. Copyright © 2010 John Wiley & Sons, Ltd.     

A bio-inspired mobile agent-based integrated system for flexible autonomic job shop scheduling

This paper presents a bio-inspired mobile agent-based integrated system for flexible autonomic job shop scheduling. The system matches the autonomic system architecture, inspired by the autonomic nervous system and proposed by the IBM, and has the IBM-defined fundamental self-managing properties, so that it can manage itself with little human intervention. The system conforms to the IEEE FIPA (Foundation for Intelligent Physical Agents) standard. Therefore, the interoperability between agents of the system and agents from many active heterogeneous FIPA compliant agent platforms can be ensured. The system supports the execution of C/C++ mobile agent codes. Thus, it is applicable to a variety of applications, especially for distributed mechatronic and embedded systems. In addition, since the system is composed of agents, including stationary and mobile agents, the system has a high scalability and flexibility to integrate and adopt various scheduling models and algorithms for different scheduling requirements. An overall architecture of the system and critical implementation details about the agency and agents in the system are presented in this article. An energy saving job shop scheduling example is used to validate one autonomic property of the system.     

Mobile agent‐based computational steering for distributed applications

The mobile agent‐based computational steering (MACS) for distributed applications is presented in this article. In the MACS, a mobile agent platform, Mobile‐C, is embedded in a program through the Mobile‐C library to support C/C++ mobile agent code. Runtime replaceable algorithms of a program are represented as agent services in C/C++ source code and can be replaced with new ones through mobile agents. In the MACS, a mobile agent created and deployed by a user from the steering host migrates to computing hosts successively to replace algorithms of running programs that constitute a distributed application without the need of stopping the execution and recompiling the programs. The methodology of dynamic algorithm alteration in the MACS is described in detail with an example of matrix operation. The Mobile‐C library enables the integration of Mobile‐C into any C/C++ programs to carry out computational steering through mobile agents. The source code level execution of mobile agent code facilitates handling issues such as portability and secure execution of mobile agent code. In the MACS, the network load between the steering and computing hosts can be reduced, and the successive operations of a mobile agent on multiple computing hosts are not affected whether the steering host stays online or not. The employment of the middle‐level language C/C++ enables the MACS to accommodate the diversity of scientific and engineering fields to allow for runtime interaction and steering of distributed applications to match the dynamic requirements imposed by the user or the execution environment. An experiment is used to validate the feasibility of the MACS in real‐world mobile robot applications. The experiment replaces a mobile robot's behavioral algorithm with a mobile agent at runtime. Copyright © 2009 John Wiley & Sons, Ltd.     

An embeddable mobile agent platform supporting runtime code mobility,interaction and coordination of mobile agents and host systems

Agent technology is emerging as an important concept for the development of distributed complex systems. A number of mobile agent systems have been developed in the last decade. However, most of them were developed to support only Java mobile agents. In order to provide distributed applications with code mobility, this article presents a library, the Mobile-C library, that allows a mobile agent platform, Mobile-C, to be embeddable in an application to support mobile C/C++ codes carried by mobile agents. Mobile-C uses a C/C++ interpreter as its Agent Execution Engine (AEE). Through the Mobile-C library, Mobile-C can be embedded into an application to support mobile C/C++ codes carried by mobile agents. Using mobile C/C++ codes, it is easy to interface a variety of low-level hardware devices and legacy systems. Through the Mobile-C library, Mobile-C can run on heterogeneous platforms with various operating systems. The Mobile-C library has a small footprint to meet the stringent memory capacity for applications in mechatronic and embedded systems. The Mobile-C library contains different categories of Application Programming Interfaces (APIs) in both binary and agent spaces to facilitate the design of mobile agent based applications. In addition, a rich set of existing APIs for the C/C++ interpreter employed as the AEE allows an application to have complete information and control over the mobile C/C++ codes residing in Mobile-C. With the synchronization mechanism provided by the Mobile-C library for both binary and agent spaces, simultaneous processes across both spaces can be coordinated to get correct runtime order and avoid unexpected race condition. The study of performance comparisons indicates that Mobile-C is about two times faster than JADE in agent migration. The application of the Mobile-C library is illustrated by dynamic runtime control of a mobile robot’s behavior using mobile agents.     

The State of the Art in Agent Communication Languages

Like societies of humans, there is a need for agents in a multi-agent system to rely on one another, enlist the support of peers in order to solve complex tasks. Agents will be able to cooperate only through a meaningful communication language that can bear correctly their mental states and convey precisely the content of their messages. In search for the ideal agent communication language (ACL), several initiatives like the pioneering work of the Knowledge Sharing Effort and the Foundation for Intelligent Physical Agents (FIPA) are paving the way for a platform where all agents would be able to interact regardless of their implementation environment. ACL is a new field of study that could gain from a survey in expanding its application areas. For this purpose, we examine in this paper the state of the art in ACL design and suggest some principles for building a generalized ACL framework. We then evaluate some existing ACL models, and present the current issues in ACL research, and new perspectives. Received 22 July 1999 / Revised 23 March 2000 / Accepted 2 May 2000     

一种移动Agent通信协作模型

基于FIPA ACL和Linda协作模型的思想和方法，提出一种移动Agent通信协作模型Wagent模型。这种通信协作模型结合了FIPA ACL和Linda协作模型各自的优点，解决基于语义的协作和移动Agent的通信失效问题。在IBM的Aglet平台上，实现这种通信协作模型。     

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.     

JADE implemented mobile multi-agent based,distributed information platform for pervasive health care monitoring

In this paper we aim to implement a highly distributed information infrastructure—MADIP by using Intelligent Agent paradigm, which is able to notify the responsible care-provider of abnormality automatically, offer distance medical advice, and perform continuous health monitoring for those who need it. To confront the issues of interoperability, scalability, and openness in heterogeneous e-health environments, a FIPA2000 standard compliant agent development platform—JADE (Java Agent DEvelopment Framework) was adopted for the design and implementation of the proposed intelligent multi-agent based MADIP system.     

Developing Real Applications With Agent Technologies

In this paper, we present an agent library to develop multi-agent applications. Such an agent library has been realised taking into account FIPA specifications. FIPA specifications give the minimum amount of technology deemed necessary for the management of agents in an open agent system, including agent roles, an agent communication language, an agent management content language, and a standard way to interact with non-agentised software.Therefore, the library offers the prototypes of the agents necessary for the management of a FIPA agent open system and an agent prototype that the user can specialise to build the other agents necessary for her/his application. The library has been implemented both in C++ and Java. The two implementations support a logical distribution, i.e., the agents correspond to different threads, and a physical distribution, i. e., agents of the same applications run on different machines. The Java library has been used to develop a multi-agent system, that facilitates users to use a video on demand service, and a first prototype of the system is under experimentation. The C++ library is used for the development of a multi-agent system that should integrate the different software modules performing sensory data interpretation, planning, faults diagnosis, . . . of a robot working in a space station.     

Integrating mobile agents into the mobile middleware

Mobile agents are a new paradigm for distributed computing that is especially well suited for mobile computing over global wireless networks. This paper describes the approach taken in the ACTS On TheMove project to integrate a mobile agent system into the Mobile Application Support Environment (MASE), a middleware for mobile computing. In this project, an existing mobile agent system was adapted for the requirements of mobile computing. We present the changes that had to be made to the agent system to adapt it to the wireless communication. We also present some of the application areas where a mobile agent system is suitable for mobile communication. We describe an agent based pre-fetcher application where an agent operaes disconnected from the user on the fixed network and prepares web pages for the anticipated next connection of the user using the Quality-of-Service trading functions available in MASE.     

Deploying FIPA-compliant systems on handheld devices

LEAP is a runtime environment for deploying agents on a network of Java-enabled devices. It complies with FIPA international standards for multiagent systems. The Lightweight Extensive Agent Platform project is the first attempt to implement a FIPA agent platform that runs seamlessly on both mobile and fixed devices over both wireless and wired networks     

移动代理互操作性研究

主要阐述如何解决移动代理互操作性方面的问题，通过深入分析与移动代理系统互操作性有关的CORBA，MASIF和FIPA规范，系统地提出了移动代理技术与三者结合实现互操作性的可能性和必然性，并且从理论上进行了分析和论证，给出了实现方法。     

GCS-MA: A group communication system for mobile agents

Reliable messaging is a key component necessary for mobile agent systems. Current researches focus on reliable one-to-one message delivery to mobile agents. But how to implement a group communication system for mobile agents remains an open issue, which is a powerful block that facilitates the development of fault-tolerant mobile agent systems. In this paper, we propose a group communication system for mobile agents (GCS-MA), which includes totally ordered multicast and membership management functions. We divide a group of mobile agents into several agent clusters, and each agent cluster consists of all mobile agents residing in the same sub-network and is managed by a special module, named coordinator. Then, all coordinators form a ring-based overlay for interchanging messages between clusters. We present a token-based algorithm, an intra-cluster messaging algorithm and an inter-cluster migration algorithm to achieve atomicity and total ordering properties of multicast messages, by building a membership protocol on top of the clustering and failure detection mechanisms. Performance issues of the proposed system have been analysed through simulations. We also describe the application of the proposed system in the context of the service cooperation middleware (SCM) project.     

Causality for debugging mobile agents

Mobile agents, i.e. pieces of programs that can be sent around networks of computers, appear more and more frequently on the Internet. These programs may be seen as an enrichment of traditional distributed computing, and structuring applications using mobile agents is destined to become the de facto way of constructing distributed systems in the near future. Since mobile agents may carry communication links with them as they move across the network, they create very dynamic interconnectio n structures that can be extremely complex to analyse. In this paper we study an example of a system based on the mobile agent principle, written in the Facile programming language. We propose a Structural Operational Semantics (SOS) for Facile, giving a proved transition system that records encodings of the derivation trees of transitions in their labels. This information enables us to easily recover non-interleaving semantics for Facile by looking only at the labels of transitions. We use the new semantics to debug an agent based system. This example is a scaled down version of a system demonstrated at the European IT Conference Exhibition in Brussels, 1995. We also adopt our causal semantics to analyse the specification of a prefetch pipeline processor. Received: 14 November 1997 / 30 April 1999     

Salient object detection using biogeography-based optimization to combine features

In recent studies, ontology related concepts have been introduced into FIPA ACL content language to convey information for agent communication. However, these works have only applied ontology-based knowledge representation in communication message and then demonstrated the advantage of this association. In fact, although ontology can represent semantic implications needed for decidable reasoning support, it has no mechanism for defining complex rule-based representation to support inference. The motivation of this study is to address this issue by developing a semantic-based infrastructure to integrate Semantic Web technologies into ACL message contents. This semantic-based infrastructure defines two different semantic frameworks: the three-tier knowledge representation framework for message content and the Multi-layer Ontology Architecture for content language. The former is developed based on Semantic Web stack to support ontology-based reasoning and rule-based inference. The latter is adopted to develop a Lightweight Ontology-based Content Language (LOCL) to describe agent communication messages in an unambiguous and computer-interpretable way Jena reasoner is used in an application scenario that exploits agent communication with LOCL as content language, OWL as ontology language, and SWRL as rule language to demonstrate the feasibility of the proposed infrastructure.     

Detecting and resolving deadlocks in mobile agent systems

Mobile agents environment is a new application paradigm with unique features such as mobility and autonomy. Traditional deadlock detection algorithms in distributed computing systems do not work well in mobile agent systems due to the unique feature property of the mobile agent. Existing deadlock detection and resolution algorithms in mobile agent systems have limitations such as performance inefficiency and duplicate detection/resolution when multiple mobile agents simultaneously detect/resolve the same deadlock. To address these problems, we propose an improved deadlock detection and resolution algorithm that adopts priority-based technique and lazy reaction strategy. The priority-based technique aims to ensure that there is only one instance of deadlock detection and resolution, and it also helps reduce mobile agent movement and data traffic together with the lazy reaction strategy. The liveness and safety properties of the proposed algorithm are proved in this paper. Theoretical analysis and experimental results show that the proposed algorithm provides better performance in terms of agent movement, data traffic, and execution time.     

Distributed directory service and message routing for mobile agents

Research about networks and agents has identified the need for a layer that provides a uniform protocol to communicate with fixed and mobile agents. In order to preserve the compatibility with existing infrastructures, proposed solutions have involved a “home agent”, which forwards messages to a mobile entity. The mechanism of a home agent puts a burden on the infrastructure, which may hamper the scalability of the approach, in particular, in massively distributed systems, such as the amorphous computer or the ubiquitous/pervasive computing environment. Free from any compatibility constraint, we have designed an algorithm to route messages to mobile agents that does not require any fixed location. The algorithm has two different facets: a distributed directory service that maintains distributed information about the location of a mobile agent, and a message router that uses the directory service to deliver messages to a mobile agent. Two properties of the algorithm were established. Safety ensures that messages are delivered to the agent they were aimed at, whereas liveness guarantees that messages eventually get delivered. A mechanical proof of the properties was carried out using the proof assistant Coq.     

Agent-based artificial immune system approach for adaptive damage detection in monitoring networks

This paper presents an agent-based artificial immune system approach for adaptive damage detection in distributed monitoring networks. The presented approach establishes a new monitoring paradigm by embodying desirable immune attributes, such as adaptation, immune pattern recognition, and self-organization, into monitoring networks. In the artificial immune system-based paradigm, a group of autonomous mobile monitoring agents mimic immune cells (such as B-cells) in the natural immune system, interact locally with monitoring environment, and respond to emerging problems through simulated immune responses. The presented immune-inspired monitoring paradigm has been applied to structural health monitoring. The “antibody” of a mobile monitoring agent is a pattern recognition algorithm tuned to a certain type of structural damage pattern. The mobile monitoring agent performs damage diagnosis based on structural dynamic response data. Mobile monitoring agents communicate with each other and collaborate with network components based on agent interaction protocols defined in agent standards, the Foundation for Intelligent Physical Agents standards. A mobile agent system embedded in sensor nodes supports the selective generation, migration, communication, and management of mobile monitoring agents automatically. The active structural health monitoring is achieved by distributing mobile monitoring agents to the sites where they are needed. The structural damage diagnosis using mobile monitoring agents and artificial immune pattern recognition method has been tested using a scaled steel bridge structure. The test result shows the feasibility of using this approach for real-time structural damage diagnosis.     

基于Socket的异构形平台的网络通信研究

介绍了如何在C／C＋＋和Java两种不同平台上进行网络套接字通信，并结合移动行业自助服务通信系统工程实例研究了两种平台Socket通信的不同以及通信中的一些关键注意问题。