Elena Nardini

Self-aware Pervasive Service Ecosystems

Here we present the overall objectives and approach of the SAPERE (“Self-aware Pervasive Service Ecosystems”) project, focussed on the development of a highly-innovative nature-inspired framework, suited for the decentralized deployment, execution, and management, of self-aware and adaptive pervasive services in future network scenarios.

Coordination in open and dynamic environments with TuCSoN semantic tuple centres

With the goal of addressing open and dynamic scenarios like the Web, in this paper we introduce a semantic-oriented extension of the tuple space model. In our model, each tuple space is equipped with the ontological description of the coordination domain (e.g. expressed in W3Cs OWL language). Tuples represent individuals of the domain along with their properties, and retrieval templates correspond to queries used to check whether an individual is the instance of an ontological concept (as typical in Description Logics, the logic of semantic reasoning). Differently from existing approaches in literature, we obtain a model that is fully expressive -- compared to OWL -- with a smooth extension of the standard syntactic setting of tuple spaces, namely, by an intuitive extension of the language for tuples and tuple templates. We discuss an incarnation of this model in the TuCSoN coordination model and infrastructure.

Coordinating e-health systems with TuCSoN semantic tuple centres

Open and distributed application scenarios like e-Health systems mandate for new coordination models and technologies. In particular, they require middleware providing coordination and security services modelled with abstractions promoting run-time observability and adaptation. Along this line, in this paper we describe the architecture of the TuCSoN coordination infrastructure, and show its application to an e-Health application scenario.

Situated process engineering for integrating processes from methodologies to infrastructures

In the field of Multi-Agent Systems (MASs), methodologies and infrastructures have developed in the last years along two opposite paths: while Agent-Oriented methodologies have essentially undergone a top-down evolution, MAS infrastructures have mostly followed a bottom-up path, producing a conceptual gap between methodologies and the available agent infrastructures. This paper aims at defining a method for filling such a gap, based on Situational Method Engineering (SME) and SPEM (Software Process Engineering Meta-model). After highlighting the lack of sufficient research and understanding about the role of the infrastructures in the software engineering process, we show that infrastructures, like methodologies, have processes behind them, and propose a method based on the integration of the processes underpinning both methodologies and infrastructures. Then, we validate such an approach by showing how the process of the SODA methodology can be integrated with the process of the TuCSoN infrastructure using SME and SPEM.

SPEM on test: the SODA case study

In the Software Engineering (SE) research field, several efforts are underway aimed at developing appropriate meta-models for SE methodologies. Meta-models are meant to check and verify both the software development process and the completeness and expressiveness of methodologies. In this context, in order to provide a uniform way to represent, compare and reuse methodologies, Software Process Engineering Meta-model (SPEM) -- an OMG object-oriented standard -- is a natural candidate. In order to put the SPEM meta-modelling power to test, and emphasise its benefits and limitations, in this paper we apply SPEM to a more articulated context than the object-oriented one where it was initially conceived -- that is, Agent-Oriented Software Engineering (AOSE) methodologies. In particular, we take the SODA methodology as a significant case study in order to assess strengths and limitations of SPEM, given the peculiar SODA focus on the modelling and engineering of (i) social issues and (ii) application environment -- essential aspects in the engineering of complex software systems.

Description spaces with fuzziness

Extending tuple spaces with Description Logic provides a coordination model particularly suitable for open and dynamic application domains like pervasive systems, Internet applications and service-based applications. However, description logic per se is not powerful enough to represent vague/fuzzy knowledge so often required by real-world application scenarios. Hence, in this paper we extend the model of Description Logic tuple spaces (Description Spaces, or DS, in short) with fuzziness in order to support fuzzy semantic coordination.

Semantic tuple centres

In order to address open, distributed, and knowledge-intensive scenarios, we introduce a semantic-oriented extension of the tuple centre coordination model. There, each tuple centre is extended with the ontological description of the coordination domain, expressed by means of the W3C standard OWL. Unlike existing approaches in the literature, our coordination model smoothly extends the standard syntactic setting of tuple spaces, allowing tuple centres to encapsulate the semantic representation of the domain of discourse, and to embody semantic coordination policies. In order to test the feasibility of our approach, a prototypical implementation of our model in the TuCSoN infrastructure featuring the Pellet semantic reasoner is described and discussed.

A Coordination Approach to Adaptive Pervasive Service Ecosystems

Technology evolution is providing new pervasive service scenarios characterised by a huge number of distributed and dynamic devices. Accordingly, a new generation of services and infrastructures are emerging which support situatedness, adaptivity and diversity. In this paper we model the overall world of services, data and devices, as a distributed computational ecosystem. As such, each entity will be modelled as an autonomous, spatially-situated individual of the ecosystem, whose existence and state is reified by an LSA (Live Semantic Annotation). Ecosystem behaviour is controlled by coordination rules called eco-laws, which are chemical-like reactions evolving the population of LSAs. We describe an architecture supporting this vision along with a model of eco-laws, and show their usefulness in a scenario of adaptive pervasive displays.

Towards a pervasive infrastructure for chemical-inspired self-organising services

Stimulated by the increasing availability of new mobile computing devices and the corresponding demand of open, long-lasting, and self-organising service applications, recent works proposed the adoption of a nature-inspired approach of chemistry for implementing service architectures [33]. One work in this direction is the chemical tuple-space model [30], by which the existence of data, devices and software agents (in one word, services of the pervasive computing application) gets reified into proper tuples managed by the infrastructure. System behaviour is accordingly expressed by chemical-like reactions that semantically match those tuples and accordingly enact the desired interaction patterns (composition, aggregation, competition, contextualisation, diffusion and decay). After motivating the proposed approach for situated, adaptive, and diversity-accommodating pervasive computing systems, in this paper we outline an incarnation of this model based on the TuCSoN coordination infrastructure, which can been suitably enhanced with modules supporting semantic coordination and execution engine for chemical-inspired coordination laws.

General-Purpose Coordination Abstractions for Managing Interaction in MAS

Interaction represents one of the main sources of complexity in Multi-agent Systems (MAS). As a consequence, coordination – as the management of the space of system interaction – plays a key role in the engineering of MAS. In this context, the tuple centre coordination abstraction have been experimented in MAS to manage interaction among agents and between agents and MAS environment. Along this line, the aim of this paper is to test the expressive power of tuple centres as the unifying abstractions to model and govern the whole range of admissible interactions within a MAS. For this purpose, we take the notion of Agent Coordination Context (ACC) – aimed at supporting interaction between an individual agent and the MAS as a whole – and show how it can be implemented in terms of a tuple centre in a MAS infrastructure. In particular, we adopt ReSpecT tuple centres as the coordination abstractions and TuCSoN as the coordination infrastructure managing the space of interaction in a MAS, and provide an example of how the TuCSoN ACC can be implemented by means of a suitably-programmed ReSpecT tuple centre.