Mes: diciembre 2008

From Agents to Artifacts Back and Forth
In MAS, environment is considered as a monolithic and centralised component. This paper proposes a model based on artifacts. An artifact has (i) an user interface that provide operations for using it, (ii) the observable state, (iii) a mechanism to signal to external artifacts and (iv) a link interface to link to other artifacts.

But artifacts are not agents, they only react, they’re passive. And they are not objects either. A sample is shown in Cartago architcture. From the agent viewpoint, artifacts embedded operational and epistemic functions.

Towards Agent-Oriented Model Driven Engineering
To create MAS is a complex activity and many methodologies integrate MDE principles. MDE is based in the concept of model. They’re talking abut how differente methodologies, such as Ingenias or Adelfe are using MDE concepts. Some considerations: (i) concepts are still evolving, (ii) own semantic concepts, (iii) a wide range of levels of abstraction. They propose Model transformation By Example (MTBE), creating automatic transformation between pairs of models and shows some examples about how it works. The idea is to provide the tools with pairs of models that correspond to a transformation, so the systmen could learn from the and apply it to other cases. An very intersenting open issue-future work is how to include negative examples.

Reducing Communication Cost Via Overhearing
Showing how to reduce the communnoication cost by using mediators that filter invalid illocutions. The cost depends on the bandwith of the communication channel and the ammount of CPU (processing time) used to detect invalid illocutions. Interesting… and some ideas that I can use for SF distribution.

Towards Organizational Agent-Oriented Operating Systems
(Confirmado… Pixel sabe leer :-) Agent are complex systems but agents and even their platforms have no help from the operative system (OS), so they (we) are trying to define-and meybe to create-an OS that incorporate more complex abstractions to facilitate the execution of the agents.

Instead of being the process the basic exectional entity, agents organisations are included into the OS. Its based on a client-server view (I don’t like it), where there’re agents that provide services and others than ask from them. Services can be classified into two types: operations and resources. Operation serv. are sw services executed by an agent (open) and Resource serv. are hw services provided by devices.

What’s the difference between this proposal and middleware? I guess that it complicates a lot the OS design without giving clear advantages. I think that is better to provide basic management for agent concepts (as communication, roles, norms, organisations and so on), but we don’t need to have agents inside the operative systems.

Tags: agent, developtment, mdd, mda, communication, cartago, ingenias, adelfe

Programming Social Processes with Action Languages
A social process is a joint of activities (business, poitical, administrative and so on) performed in a social context. It can be a computational society when a :SocialMiddleware is provided and it can be programmed as a first-class social connector (:SocialInteraction). The abstract machine for the SOcialMiddleware they use action languages (C+): a declarative language to specify structure and dynamics, based upon a propositional, non-monotonic, causal logic, and Ccalc tool (SAT solver).

The social middleware is defined through a set of sorts, objects, fluents, actions, variables and axioms. But to reduce the complexity of these specifications they make a sort-oriented specification. He explains using a tennis match example how the society can be modelled.

WIth all that, a programming language for agent societies can be defined (SPEECH: a societal programming language – www.speechlang.org).

Representing and Reasoning about Norm-Governed Organisations with Semantic Web Languages
SW languages are more limited, but they offer a stardard language (open), advantadges in reasoning (decidability and optimized reasoners). They want to capture roles and role classification, institutionalised powers, normative systems, violations and temporal relationships (hey…. just as I want!!! I have to read it carefully). OWL and SWRL extended for temporal relations (SWRLTab editor) for before, after and during (–> converted into PDDL).

They define permissions, abbligations and permision for roles and inheritance of norms. You can override them if you need more especific norms. There’re general rules form norms (ex. if an act is permitted then it’s not prohibited / if an act is obligatory the it’s permitted… ) Other cocept modelled is «power» (a role has the powerto execute an action). Norms can have conditions and deadlines, but the DL reasoner has to be extended to del with temporal relationships (this can be an interesting work to do) To detect violations, the system can check if an agent triesto perform an act that is prohibited. That can be detected automatically by the reasoner.

But we can reason an inconsistent ontology by tolerating contradictions (that’s interesting for open systems or self-organising systems)

Limitations (comparing with event calc.): only binary operators, static knowledge, no modifications

On Partial Deductions and Conversational Agents
Many times, human conversations include more information that a simple yes/no answer, so if agents want to interact with human complex conversation schemes have to be included in their mental state.

The mental state of an agent is formed by a ….., a …. and a set of rules. Goals are facts that agents want to be solve. THe input and the output interface are set of facts. Agents communicate using an own simple speech act messages. Interface engine os based on rle specialisation uses an approximate reasoning context and the true value is not binary, but a fuzzy one.

Examples to show the mentak state cycle and hoe agents communicates to complete their information.

Tags: eumas, programming, reasoning, semantic web, owl, swrl, swrltab