EUMAS07. Session 7 and 8 (and final)

Well, it’s Friday afternoon and these are the latest sessions of EUMAS. None of them are specially interesting for me.

Session 7 is about simulation.
The two first articles are presented by a third person, not by their authors. And the last author hasn’t appeared yet. It seems that they are simulated authors too :-D

It begins with an article about simulation with virtual lanes for motorcycles simulation, trough microscopic simulation. The problem of current approaches is that they assume that motorcycles rides in the middle of a lane. I’ve never seen a cycle been driven like that ;-) and so do they, so they plan a more realistic scene, in which the cycle can change the lanes and uses the road marking as valid paths. That is: they are driven as motorcycles. In their proposal, each vehicle is an agent and the traffic is just an emergent behaviour of the multiagent system. Usually, only road is used, but in cases of dense traffic, all free space is used. This «new» free spaces for cycles are the virtual lanes (VLs). VLs can be authorised or forbidden depending on the position of the rest of vehicles (due to their proximity to the limits of the actual lane).Several rules to model the behaviour of the cycles are proposed (to pass on the left, to drive in the widest lane and so on).They need a deeper validation to compare with real data in the behaviour of traffic conditions and individual driver’s behaviour, and to simulate complex situations, as junctions.

Now it’s Elena’s turn, with the Gus’s paper Intelligent Agents in Serious Games. After the introduction, it classifies the different approaches in four types:

  • agent-centered, in which the agent is the main element. Used in cases as virtual population or mimicking human users.
  • abstract agents, where the global systems is the most important and it emerges from the interactions. Examples are polkitical and social act simulation (as wars)
  • agent and network topologies, where the topology of the network is the most important and the agents are merely resources.
  • full approach, a mixture of the three previous approaches.

The problem is that there is not an agent model common for all these approaches so,tachaaaan, we propose our unified agent model for serious game: Spade (see references). A couple of questions, but Elena can’t answer them, so they will be redirected to garanda {at} X-D

The third author is virtual already, so we’ve finished.

Session 8. Metodologies and Tools

I’ve arrived late to the first one, but it sounds a bit rare. I haven’t understood their purpose: testing agents for bugs in their codification? I’m not sure.

The second one is about security in mobile agent systems for open environment. Current solutions, as DNS or FIPA-AMS are not usefull. Agent location service requires to be efficient, by dealin with dynamic information and to be scalable, and to be secure. And they are looking for a model that provide transparent location for agents. They’ve consider several alternatives–(de)centralised, hierarchical/P2P– The solution is a Fonkey-based location server. The idea is that every information have to be signed. It is a platform to provide secure communications for agent platforms. May be is what we get with Kerberos for Magentix (some how). At the end, he recognises that send packages in DHT is expensive.

Now is Jose Miguel’s turn with Magentix. Only sockets can be used to communicate processes in different machines, so the efficiency of communication among agents depends on the efficiency of socket management. Comparing Java with TCP-based pure communication, the former is clearly the loser (obviuos). After that, he continues explaining the Magentix agent platform and its performance. Any questions? Yes. The first one is about the scalability of AMS, because white pages are all replicated in all hosts. Other question is that we’re are making platform dependent something that is platform independent. And a pair of questions more. A lot of criticism; I guess that Magentix hasn’t convinced.

The last paper is about a methodology called ASEME. The analyse the systems using capabilities and functionalities., The design phase models the intra-agent and inter-agent control. The design phase ends with a platform independent model (PIM) and uses PSMs in the implementation phase (I have to review again our MDA-based proposal). Till now, it is just another methodology. I think that agent community needs a common methodology (as UML for OOP) and its own high level language. I’m bored of different methodologies (our own methodologies are included). Something interesting is the use of statecharts for representing protocols, because its more important to establish the activities that the agent have to do when a message arrives. Furthermore, it can be easily linked with the rest of agent activities.

Some that I have to read is something about SPEM. It seems to be a notation to describe the different phases of a methodology. Maybe it will be interesting for Thomas.

Well, and here finishes the 5th European Conference on Multiagent Systems. I’ll summarise the conference in one last post.

Greetings from Hammamet.

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EUMAS07. Invited talk Leila Amgoud

The EUMAS ’07 begins with the invited talk of Leila Amgoud titles «Modelling Negotiation Dialogs Using Argumentation».

At the moment, it’s been a very basic talk explaining what’s negotiation between autonomous agents. After explain what negotiation is, she talks about the approaches to the negotiation process: game theory, heuristics and argumentation based approaches.

Game theory
As a branch of economics, assumes perfect rationality (all information is know), not an actual case. It not says anything about how the utility function is calculated and the agents can only emit proposals.

Agents don’t know each other preferences, but they only exchange proposals and the preferences of each agent are fixed.

We can influence the preference relation of other agents, because we interchange proposals and arguments to «convince» the other agent.
Now she continues explaining things about argumentation. Differentiates between two types of arguments: epistemic and practical. The former supports beliefs and is used in deductive reasoning, whereas the latest is based on proposals and is used in abductive reasoning. It’s explaining basic things again (attacks, conflict-free sets…). Arguments can be credulitily or skeptically accepted or rejected. To the argumentation process take into account only the skeptical ones or the rejected to order the offers.

And now…. begins the interesting part: how to use argumentation in negotiation processes (it has taken her 40 min.!!)

She defines 3 protocol classes, but I hardy can read the slides.

… and 3 types of strategies depending on

  1. which offer/proposal to send/accept (the most used one)
  2. which argument to send

Well. this where the important part of the conference and she have used just 2 slides :-( Instead of explaining the strategies, she’s continuing with an example. She compares one example without argumentation. The agents can be jammed, but the problem is solve if they can argument about their preferences (obviously).

The problem is if an optimal solution can be reached quikly. But I thing that this is not too importal. Actual life is full of non-optimal negotiations, but good enough ones. She says that they ¡’re looking for a metamodel of decision making and a general model for allowing multiattributes negotiations.

And…. that’s all, folks. Some questions and we’ll run for the next session. By, then.

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EUMAS 07. Un viaje accidentado

Bueno, por fin hemos llegado a Hammamet (Tünez) depués de un viaje accidentado: perdimos el enlace en Parías y tuvimos que esperar 2 horas en el aeropuesrto. El segundo avión salió casi una hora tarde y perdimos el autobús en Túnez. Allí nos tocó esperar 4 horas a que Mr. Transportation llegara con uno mayor.

Al final llegamos a Hammamet a las 9 de la noche. Me había levantado a las 4.30 de la mañana. Y, por supuesto, no llegué al 5th technical forum: la razón por la que vine a Túnez. Mola ¿eh?

Esta mañana ya nos hemos inscrito en la conferencia, hemos desayunado y ahora estoy en la conferencia invitada sobre el uso de técnicas de argumentación para negociación. Nos han dicho que teníamos que haber pagado el hotel a través de EUMAS. Imagino que eso supone que habrá que pagar un «extra» por algo (uso de las salas, WiFi o lo que sea), por eso era más caro.

Ya os contaré como va el resto.

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