Interaction protocols play a fundamental role in multiagent systems. In this work, after analyzing the trends that are emerging not only from research on multiagent interaction protocols but also from neighboring fields, like research on workflows and business processes, we propose a novel definition of commitment-based interaction protocols, that is characterized by the decoupling of the constitutive and the regulative specifications and that explicitly foresees a representation of the latter based on constraints among commitments. A clear distinction between the two representations has many advantages, mainly residing in a greater openness of multiagent systems, and an easier reuse of protocols and of action definitions. A language, named 2CL, for writing regulative specifications is also given together with a designer-oriented graphical notation.

Abstract. Global choreographies define the rules that peers should respect in their interaction, with the aim of guaranteeing interoperability. An abstract choreography can be seen as a protocol specification; it does not refer to specific peers and, especially in an open application domain, it might be necessary to retrieve a set of web services that fit in it. A crucial issue, that is raising attention, is verifying whether the business process of some peers, in particular the parts that encode the communicative behavior, will produce interactions which are conformant to the agreed protocol (legality issue). Such issue is tackled by the so called conformance test, which is a means for certifying the capability of interacting of the involved parts: two peers that are proved conformant to a same protocol will actually interoperate by producing a legal conversation. This work proposes an approach to the verification of a priori conformance of a business process to a protocol, which is based on the theory of formal languages and guarantees the interoperability of peers that are individually proved conformant.

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In this paper we start from the consideration that high level interaction between entities like web services has very different properties with respect to the interaction between objects at the lower level of programming languages in the object oriented paradigm. In particular, web services, for security, usability and user adaptability reasons, offer different operations to different users by means of access control and keep track of the state of the interaction with each user by means of sessions. The current vision in object orientation, instead, considers attributes and operations of objects as being objective and independent from the interaction with another object, which is sessionless. To introduce these features in the interaction between objects directly in object oriented programming languages, we take inspiration from how access control is regulated by means of roles. Roles allow objects to offer different operations depending on the type of the role, of the type and identity of the player of the role, and to define session-aware interaction. We start from a definition of roles given in ontologies and knowledge representation and we discuss how this definition of roles can be introduced in Java, building our language powerJava.

Affective computing is receiving increasing attention in many sectors, ranging from advertisement to politics. This work, set in a Social Semantic Web framework, presents ArsEmotica, an application software for associating the predominant emotions to artistic resources of a social tagging platform. Our aim is to extract a rich emotional semantics (i.e. not limited to a positive or a negative reception) of tagged resources through an ontology driven approach. This is done by exploiting and combining available computational and sentiment lexicons with an ontology of emotional categories. The information sources we rely upon are the tags by which users annotated resources, that are available through the ArsMeteo platform, and the ontology OntoEmotion, that was enriched by means of our tool with over four hundred Italian emotional words referring to the about eighty-five emotional concepts of the ontology. Tags directly referring to ontological concepts are identified, while potentially affective tags can be annotated by using the ontology, thanks to the spontaneous intervention of the users, in a pure Web 2.0 approach. Finally, the tagged artworks are related with the emerging predominant emotions. A user study involving the ArsMeteo community was conducted in order to evaluate the ArsEmotica outcome, for what concerns the emotions automatically associated by the system to the artworks.

Abstract. Communication plays a fundamental role in multi-agents systems. One of the main issues in the design of agent interaction protocols is the verification that a given protocol implementation is "conformant" w.r.t. the abstract specification of it. In this work we tackle those aspects of the conformance verification issue, that regard the dependence/independence of conformance from the agent private state in the case of logic, individual agents, set in a multi-agent framework. We do this by working on a specific agent programming language, DyLOG, and by focussing on interaction protocol specifications described by AUML sequence diagrams. By showing how AUML sequence diagrams can be translated into regular grammars and, then, by interpreting the problem of conformance as a problem of language inclusion, we describe a method for automatically verifying a form of "structural" conformance; such a process is shown to be decidable and an upper bound of its complexity is given. We also give a set of properties that describes the influence of the agent private information on the conformance of its communication policies to protocol specifications.