Mauro Gaspari

IRS-II: a framework and infrastructure for semantic web services

In this paper we describe IRS-II (Internet Reasoning Service) a framework and implemented infrastructure, whose main goal is to support the publication, location, composition and execution of heterogeneous web services, augmented with semantic descriptions of their functionalities. IRS-II has three main classes of features which distinguish it from other work on semantic web services. Firstly, it supports one-click publishing of standalone software: IRS-II automatically creates the appropriate wrappers, given pointers to the standalone code. Secondly, it explicitly distinguishes between tasks (what to do) and methods (how to achieve tasks) and as a result supports capability-driven service invocation; flexible mappings between services and problem specifications; and dynamic, knowledge-based service selection. Finally, IRS-II services are web service compatible - standard web services can be trivially published through the IRS-II and any IRS-II service automatically appears as a standard web service to other web service infrastructures. In the paper we illustrate the main functionalities of IRS-II through a scenario involving a distributed application in the healthcare domain.

Process Algebraic Specification of the New Asynchronous CORBA Messaging Service

CORBA (The Common Object Request Broker Architecture) has to continually evolve in order to cope with the changes of requirement of applications which become larger and more distributed. For this reason new features are being added to the CORBA specification, for instance the last proposal for a revised CORBA Messaging Service includes two new asynchronous models of request invocation. Since these new features will be added in the next CORBA implementations a relevant issue is to study their operational behaviour from different perspectives in order to facilitate the task of implementors. This paper addresses this issue providing an analysis of the CORBA Messaging Service which includes the new asynchronous features. In particular we illustrate how CORBA models for request invocation can be mapped into a message passing architecture based on the actor model. For this purpose we exploit an algebra of actors which supports some of the main features of the abstract Object Model of the Object Management Group, such as object identity and an explicit notion of state. This approach allows us to discuss and compare different models of request invocation in a standard process algebraic perspective for instance we show how different notions of equivalence, such as standard and asynchronous bisimulation, can be adapted to reason about CORBA.

An expert system for the evaluation of EDSS in multiple sclerosis

Multiple sclerosis is a disease of unknown aetiology. Despite several advances in therapy in recent years, some problems such as the prognostic criteria are imperfectly understood. Several experimental trials of therapy in multiple sclerosis are in course in order to discover a successful treatment. Most of these research studies use a clinical rating scale named Expanded Disability Status Scale (EDSS) as an evaluation tool for the effects of drugs. This scale is defined by a set of rules written in English which provide a numerical quantification of the neurological examination. Although EDSS has been widely used for almost 20 years, its application still depends on the interpretation of the neurologist who performs the neurological examination, and many applications of the scale performed by different neurologist on the same patient can give different results. This is a serious problem for international trials because they lack of a reliable measure of the effects of drugs. Here, we present an expert system for the automatic evaluation of EDSS in multiple sclerosis, which has been developed to overcome this problem. The expert system exploits an explicit representation of EDSS rules, it is able to explain its conclusions and it provides a revision tool to support the user if no satisfying solution can be reached. Using this expert system, clinical trials based on EDSS can benefit of a more reliable evaluation tool providing more valuable results.

Concurrency and knowledge-level communication in agent languages

Abstract In this paper we try to answer the following questions: Is it possible to program solely at the level of an agent communication language? And if this is the case, what requirements and conditions need to be taken into account? We argue that, although a number of languages defining abstract communication primitives have been proposed in the past few years, knowledge-level programming can only be supported if a number of careful assumptions about the communication primitives and the underlying architecture are made, including asynchronous communication mechanisms, reliable message passing, and nonblocking primitives. To achieve a more rigorous understanding of these issues we proceed in a formal way. First, we postulate a set of requirements that an agent communication language should satisfy to be regarded as knowledge level. Then, we define a weak agent communication language, and we show that a synchronous version of the language does not satisfy requirements for knowledge-level programming. Finally, we show how an alternative asynchronous version of the language can be defined, which avoids the aforementioned problems. To prove these results, we introduce a general framework for reasoning on communication and concurrency aspects in the context of agent communication languages.

Crash failure detection in asynchronous agent communication languages

Agent Communication Languages (ACLs) have been developed to provide a way for agents to communicate with each other supporting cooperation in Multi-Agent Systems (MAS). In the past few years many ACLs have been proposed for MAS and new standards are emerging such as the ACL developed by the Foundation for Intelligent Physical Agents (FIPA). Despite these efforts, an important issue in the research on ACLs is still open and concerns how these languages should deal with failures of agents in asynchronous MAS. The Fault Tolerant Agent Communication Language (

Refining an Automatic EDSS Scoring Expert System for Routine Clinical Use in Multiple Sclerosis

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An ACL for a Dynamic System of Agents

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