Federico Bergenti

Methodologies and Software Engineering for Agent Systems

The Grid is a large-scale computer system that is capable of coordinating resources that are not subject to centralised control, whilst using standard, open, general-purpose protocols and interfaces, and delivering non-trivial qualities of service. In this chapter, we argue that Grid applications very strongly suggest the use of agent-based computing, and we review key uses of agent technologies in Grids: user agents, able to customize and personalise data; agent communication languages offering a generic and portable communication medium; and negotiation allowing multiple distributed entities to reach service level agreements. In the second part of the chapter, we focus on Grid service discovery, which we have identified as a prime candidate for use of agent technologies: we show that Grid-services need to be located via personalised, semantic-rich discovery processes, which must rely on the storage of arbitrary metadata about services that originates from both service providers and service users. We present UDDI-MT, an extension to the standard UDDI service directory approach that supports the storage of such metadata via a tunnelling technique that ties the metadata store to the original UDDI directory. The outcome is a flexible service registry which is compatible with existing standards and also provides metadata-enhanced service discovery.

Jade — A Java Agent Development Framework

JADE (Java Agent Development Framework) is a software environment to build agent systems for the management of networked information resources in compliance with the FIPA specifications for interoperable multi-agent systems. JADE provides a middleware for the development and execution of agent-based applications which can seamless work and interoperate both in wired and wireless environment. Moreover, JADE supports the development of multi-agent systems through the predefined programmable and extensible agent model and a set of management and testing tools. Currently, JADE is one of the most used and promising agent development framework; in fact, it has a large user group, involving more than two thousands active members, it has been used to realize real systems in different application sectors, and its future development is guided by a governing board involving some important industrial companies.

LEAP: A FIPA Platform for Handheld and Mobile Devices

The ever-increasing importance of the market of portable devices is promoting the migration of technologies originally developed for the fixed network to the mobile network. This paper describes the general aim and the current results of a European-scale project intended to provide the enabling technology for deploying multi-agent systems across fixed and mobile networks. The LEAP project achieves its goal realising a FIPA platform that can be deployed seamlessly on any Java-enabled device with sufficient resources and with a wired or wireless connection. Such a platform is implemented as a new kernel for JADE to ease the migration of legacy agents to the mobile network and it exploits a modular design to scale its functionality with the capabilities of the device.

Exploiting UML in the Design of Multi-agent Systems

A basic concept of software engineering is that a system can be described at different levels of abstraction. Agent-oriented software engineering introduces a new level of abstraction, called the agent level, to allow software architects modelling a system in terms of interacting agents. This level of abstraction is not yet supported by an accepted diagrammatic notation even if a number of proposals are available. This work shows how UML can be exploited to model a multi-agent system at the agent level. In particular, it presents a set of agent-oriented diagrams intended to provide an UML-based notation to model: the architecture of the multi-agent system, the ontology followed by agents and the interaction protocols used to co-ordinate agents. The presented notation exploits stereotypes to associate an agent-oriented semantic with class and collaboration diagrams. The benefit of using stereotypes rather than extending UML to provide an agent-oriented semantic is that the presented notation can be used with any off-the-shelf CASE tool.

A collaborative platform for fixed and mobile networks

C/Webtop: providing users with a means for collaborating while on the move.

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.

A development toolkit to realize autonomous and interoperable agents

Autonomy and inter- operability are two characteristics of software agents that are advocating agent technology as an ideal candidate to support next generation of software systems. This paper presents a Java development toolkit supporting the realization of autonomous and inter- operable agents. This toolkit provides the developer with a goal- oriented agent architecture for FIPAcompliant agents. Goal- orientation supports autonomy because the developer is no longer requested to describe what the agent should do in reaction to events. To this extent, our development toolkit provides a planning engine capable of building plans to achieve the agents goals autonomously. Goal- orientation is also a key aspect of inter- operability because it is the basis of the semantics of FIPA ACL. Our development toolkit can be used at two levels of abstraction. The higher level, that we call the agent level, allows describing the agent in terms of its natural characteristics such as goals, beliefs and social organization. A code generator producing Java skeletons from UML diagrams supports this level. The developer can choose any UML CASE tool to model her agents because this code generator works with files in a standard format. The generated skeletons must be completed with application- specific code at the lower level of abstraction, that we call object level. At this level, agents are seen as Java programs and the developer is provided with a development library to integrate her code within the generated skeletons. This two- level approach allows describing agents in their natural terms at the agent level, while supporting the integration of application- specific and legacy code at the object level. Moreover, the generated code can be customized at the object level to integrate application- specific optimizations.

Three approaches to the coordination of multiagent systems

The engineering of the social aspects has been acknowledged as one of the principal issues in the realization of real-world multiagent systems. The literature proposes a number of solutions to this problem and in this paper we consider three of them and we discuss their relationships. First, we take into account hybrid coordination models based on tuple centres. Then, we consider interaction protocols as a means to coordinate multiagent systems. Finally, we address the implicit coordination that the semantics of classic agent communication languages propose. We base our discussion on the common ground of coordination models and we sketch a comparison between such approaches.

UBIQUITOUS INFORMATION AGENTS

Ubiquity is one of the most important keyword of the next generation software systems. We want our systems to follow users wherever they go, and we want our systems to extend their reach to the telephony world and to its base of several hundred million users. The ever-increasing diffusion of handy appliances, e.g. palmtops and cellular phones, is familiarizing people with the use of computers for their everyday job and, more impressively, for their everyday life. This suggests that the market of software systems for mobile applications will increase dramatically in the near future.

Interactive Workflows with WADE

In this paper we present the latest developments of WADE (Workflows and Agents Development Environment) that provide concrete support for a better realization of the innovative paradigm of agent-based business process management. First, we review the basic ideas behind such an innovative paradigm. Then, we describe the new functionality that WADE offers to enable the rapid and effective realization of user-centric business processes, i.e., business processes that are tightly integrated with the work of users and that are mainly driven by user interactions. Such processes are met frequently in practice and WADE seamlessly accommodates Web and Android users by means of dedicated views. We conclude this paper with a brief overview of notable mission-critical applications that are already using WADE and its new features.