Alfredo Garro

Method fragments for agent design methodologies: from standardisation to research

The method engineering paradigm enables designers to reuse portions of design processes (called method fragments or chunks in literature) to build processes that are expressly tailored for realising a system that is specific for some problem or development context. This paper initially reports on the standardisation attempt carried out by the FIPA Methodology Technical Committee (TC) and then presents the research activities we did starting from that work; these resulted in a slightly different definition of some of the most important elements of the approach in order to support a multiview representation of the fragment (the views are process, reuse, storing and implementation). The paper also describes the documents we used for representing a fragment and concludes with an example.

An XML Multi-agent System for E-learning and Skill Management

E-learning is nowadays recognized as one of the key components of Enterprise Knowledge Management platforms. Given a project specification, the platform should be able to suggest a project team, to measure human resources competence gaps and to contribute to reduce them by creating personalized learning paths. In this paper we propose an XML based Multi-Agent System to perform the following tasks: (i) supporting Chief Learning Officers in defining roles, associated competencies and knowledge level required; (ii) managing the skill map of the organization; (iii) measuring human resources competence gaps; (iv) supporting employees in filling their competence gaps as related to their roles; (v) enriching a given courseware or creating personalized learning paths according to feedbacks user provides in order to optimize the acquisition of needed competencies; (vi) assisting Chief Learning Offcers in choosing the most appropriate employee for a given role.

easyABMS: A domain-expert oriented methodology for agent-based modeling and simulation

Agent-Based Modeling and Simulation (ABMS) has arisen as new approach to effectively support domain experts to cope with the growing complexity of the problems which they have to face and solve. To date, few methodologies are available which can be exploited by domain experts with limited programming expertise to model and subsequently analyze complex systems typical of their application domains. In this paper the easyABMS methodology is proposed to overcome the lack of integrated methodologies able to seamlessly guide domain experts from the analysis of the system under consideration to its modeling and analysis of simulation results. The effectiveness of easyABMS is also experimented through a case study in the logistics domain which concerns the analysis of different policies for managing vehicles used for stacking and moving containers in a transhipment terminal.

Using event-driven lightweight DSC-based agents for MAS modelling

To date several agent models and related programming frameworks have been introduced for developing distributed applications in terms of multi-agent systems in open and dynamic environments. Among them, those based on lightweight architectures, asynchronous messages/events and state-based programming such as JADE, Bond and Actors have demonstrated great effectiveness for modelling open and distributed software systems. In this paper, we propose the event-driven lightweight distilled statecharts-based agent (ELDA) model which is based on the same fundamentals of the aforementioned agent models and frameworks, and provides a more effective design enabled by: a Statecharts-based specification of the agent behaviour, multiple coordination spaces for local/remote inter-agent and agent/non-agent-component interactions, and a coarse-grained strong agent mobility. A MAS based on the ELDA model can be easily designed through the ELDA meta-model and programmed through a Java-based implementation of the meta-model (ELDAFramework). Visual programming and automatic code generation of the MAS under-development is supported by an Eclipse-based visual tool (ELDATool). The produced MAS code can be executed by a discrete-event simulator framework (ELDASim) which allows for the validation of the MAS under-development. A simple yet effective case study is provided to exemplify the proposed model and its related tools.

PASSIM: a simulation-based process for the development of multi-agent systems

This paper presents the Process for Agent Specification, Simulation and Implementation (PASSIM), a simulation-based development process for Multi-agent Systems (MASs), which was obtained by integrating the well-known and established Process for Agent Societies Specification and Implementation (PASSI) methodology and a Statecharts-based simulation methodology supporting functional and nonfunctional validation of the MAS being developed. PASSIM can be effectively used as an experimental tool in the context of Agent Oriented Software Engineering (AOSE) for evaluating the benefits of using simulation for MAS development. To exemplify this process and demonstrate its effectiveness, a case study concerning the analysis, design and simulation of a complex MAS implementing an agent-based e-marketplace is defined and detailed.

Achieving Mobile Agent Systems interoperability through software layering

Interoperability is a key issue for a wider adoption of mobile agent systems (MASs) in heterogeneous and open distributed environments where agents, in order to fulfill their tasks, must interact with non-homogeneous agents and traverse different agent platforms to access remote resources. To date, while several approaches have been proposed to deal with different aspects of MAS interoperability, they all lack the necessary flexibility to provide an adequate degree of interoperability among the currently available MASs. In this paper, we propose an application-level approach grounded in the software layering concept, which enables execution, migration and communication interoperability between Java-based mobile agent systems, thus overcoming major setbacks affecting the other approaches currently proposed for supporting MAS interoperability. In particular, we define a Java-based framework, named JIMAF, which relies on an event-driven, proxy-based mobile agent model and supports interoperable mobile agents which can be easily coded and adapted to existing MASs without any modifications of the MAS infrastructures. Results from the performance evaluation of MAS interoperability was carried by using JIMAF atop Aglets, Ajanta, Grasshopper, and Voyager, demonstrating that the high-level JIMAF approach offers high efficacy while maintaining overhead at acceptable levels for target computing environments.

Single-tape and multi-tape Turing machines through the lens of the Grossone methodology

The paper investigates how the mathematical languages used to describe and to observe automatic computations influence the accuracy of the obtained results. In particular, we focus our attention on single and multi-tape Turing machines, which are described and observed through the lens of a new mathematical language, which is strongly based on three methodological ideas borrowed from physics and applied to mathematics, namely: the distinction between the object (we speak here about a mathematical object) of an observation and the instrument used for this observation; interrelations holding between the object and the tool used for the observation; the accuracy of the observation determined by the tool. Results of the observation executed by the traditional and new languages are compared and discussed.

From Modeling to Simulation of Multi-agent Systems: An Integrated Approach and a Case Study

In this paper, an integrated approach for the modeling and the validation through simulation of multi-agent systems is proposed. The approach centers on the instantiation of a software development process which specifically includes a simulation phase which makes it possible the validation of a multi-agent system before its actual deployment and execution. The approach uses the Gaia methodology for the analysis and the design, the Agent UML and the Distilled StateCharts for the detailed design, the MAO Framework for the neutral-platform implementation of software agents, and a Java-based discrete-event simulation framework for the simulation. The proposed approach is exemplified by defining and simulating a multi-agent system concerning with an agent-mediated consumer-driven e-Marketplace which offers mobile agent-based services for searching and buying goods.

On the Reliability Analysis of Systems and SoS: The RAMSAS Method and Related Extensions

This paper aims at contributing to fill the lack of methods specifically conceived for addressing the analysis and verification of nonfunctional requirements. In particular, the attention is focused on system reliability, which is a key requirement to be satisfied particularly for mission-critical systems where system failures could cause even human losses. To this end, this paper presents an up-to-date version of RAMSAS, which is a recently proposed model-based method for the reliability analysis of systems through simulation. The present version of RAMSAS is the result of an intensive experimentation phase in several application domains (avionics, automotive, and satellite) that allowed for the improvement of the effectiveness of the method, particularly in the modeling of both the intended and dysfunctional system behaviors. Moreover, this paper discusses the specific issues that arise when moving from the reliability analysis of systems to that of systems of systems (SoSs) and proposes a possible extension of the RAMSAS method (called RAMSoS) that is able to address the identified issues and thus support the reliability analysis of SoSs through simulation.

Reliability analysis of an Attitude Determination and Control System (ADCS) through the RAMSAS method

Abstract Reliability analysis of modern large-scale systems is a challenging task which could benefit from the jointly exploitation of recent model-based approaches and simulation techniques to flexibly evaluate the system reliability performances and compare different design choices. In this context, RAMSAS, a model-based method which supports the reliability analysis of systems through simulation by combining the benefits of popular OMG modeling languages with wide adopted simulation and analysis environments, has been recently proposed. This paper shows the effectiveness of RAMSAS through a real case study concerning the reliability analysis of an Attitude Determination and Control System (ADCS) of a satellite.