Agreement Technologies and Social Neuroscience

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Los días 18 y 19 de  febrero tendrá lugar el workshop Agreement Technologies and Social Neuroscience, organizado dentro del proyecto Agreement Technologies. Se trata de un workshop multidiciplinar para tratar de comprender mejor cómo se pueden modelar acuerdos dentro de un contexto social entre

El año pasado asistí y la verdad es que resultó muy interesante: hablar con expertos de áreas que no tienen que ver nada con la mía… ni siquiera con la informática, descoloca un poco pero es muy enriquecedor. Si te gustan estas cosas te recomiendo que vayas. Si hay hueco, yo pretendo ir.

Si quieres saber algo más, aquí tienes el programa y los resúmenes de las ponencias…. y no voy a escribir más frases que empiecen con “si”.

Thomas. A Service Oriented Framework for Virtual Organizations

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Es el título de la demo que hemos mandado al AAMAS 2010. Thomas es entorno que permite formar organizaciones virtuales abiertas que pueden evolucionar con el tiempo y permiten a los agentes inteligentes registrarse en ellas e interactuar con el resto de agentes a traves, principalmente, de la invocación de servicios.

Como el vídeo incluye pantallas de la aplicación, se ve mejor en pantalla completa o directamente la versión en HD en vimeo.

Sobre todo, gracias a Elena y a Natalia por el esfuerzo en tenerlo todo listo a tiempo.

EUMAS 09. Session 6. Negotiation, Dialog and Laws

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Managing quality in agent dialogues
Josep Puyol-Gruart

Measuring the quality of answers in agent’s conversations. Quality measures:
precision (smaller interval) and certainly (how close is to true or false). They are related: precision is more interesting when certainly is close to true or false. Talking about absolute (values for the facts) and relative (external view) quality. But explaining all these thing he’s run out of time, so he can’t explain how agents can use this quality measures.

Designing Automated Agents Capable of Efficiently Negotiating with People – Overcoming the Challenge
Raz Lin

It’s very difficult to design domain independent agents that negotiate with other agents or with people, and this is the goal of the paper. HE establihes the negotiation environment, how the agent isdesigned and shows some samples in games andother environments: Diplomacy, autONA, Cliff-Edge… finishing with the KBAgent, which includes all the characteristics developed in the previous ones

  • Generic agent / domain independent
  • Qualitative decision making
  • Non deterministic behavior / randomization
  • Incorporating data from past interactions

And now something about validation. It is a problem because it is no standard fto do that. What is a ‘good’ agent? maximal payoff/maximal social welfare/end with agreement/pass Turing test? This is an open question.

A good question from Ingrid Nunes abuot emotions, because their influence in human negotiations. But at the moment they are not taken into account

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Applying Model Driven Development in MAS for limited devices

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Como es costumbre, os dejo aquí mi presentación del artículo de EUMAS ’09. Que el título no engañe: habla más de MDD que de sistemas limitados aunque el ejemplo que ponemos sea de Android. Esta vez me ha costado mucho terminarla y aún así el resultado tampoco me convence demasiado… la he reordenador un millón de veces.

EUMAS 09. Session 3. Self-* and organization

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Topology and memory effect on convention emergence
Daniel Villatoro

Sorry, I’m a bit late, but this is the ideas that I’ve seen before, so I hope I’ll be able to complete this part later.

Measures of Context-Awareness for Self-Organizing Systems
Andrei Olaru

Points in common of selforg and ambient intelligence (a boring part about reactive and congnitive agents that I’m not going to comment) and now a bit about context-awareness. Agents connected in agrid with 8 neig (similiar to Kleinberg structure). Two measures: (i) pressure: how important a piece of information is; it represents urgency and determines how important the information is and how it is propagated; and (ii) interest (similar to attention focus) related with data, agents and facts. Showing how information is propagated.

Dynamic Evolution of Role Taxonomies through Multidimensional Clustering in Multiagent Organizations
Ramon Hermoso (a.k.a. Dani Mateo :-)

Related with adaptive organizations. When an agent arrives to a organization, it has to choose a counterpart to interact with. They propose a mechanism to create role taxonomies and to allow them to evolve (that is, to modificate them and, sometimes, to create new ones).

Some comments: Are always new roles specializations of existing ones? Are new roles based on existing actions? Removing roles? Has it any sense? (better remove it when there is no agents in it? who decides the role fora existing agents (supervision??

A Taxonomy of Adaptive Systems
Jan Calta

Talking about self-* properties:

  • self-stabilization (SSS) = closure +convergence
  • selg-organization (SOS) = adaptability +decentralization + local knowledge + homogeneity
  • self-management (SMS)  = configuration + optimization + healing (fixing)+ protection
  • self-adaptation (SAS) = can be considered as a generalization of SSS, SOS and SMS.

Conparing these three approaches in terms of adaptation, architecture and the approach used in their design. Interesting to describe correctly consensus networks. I think that is a SOS+SSS system (importance of the convergence)

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EUMAS 09. Session 2. Trust and Reputation

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A Trust Aggregation Engine that Uses Contextual Information
Joana Urbano

Enhacing traditional aggregation approaches by the inclusion of dynamics and being situation-aware (context).

Dynamics, based on Hysteresis of Trust and Betrayal (Straker, 2008), introducing 3 properties as asymmetry, maturity and distinguishable past. Thier model is called SinAlpha. Asymmetry penalizes intermittent behav., maturity avoids selection with few evidences and distiguishably prevents fast forgiveness. But the sin approach is not better than the linear model (experimentally).

Situation-aware is covered by contextual fitness. It is something very similar to CBR: clustering, stereotype extraction, analysis of similarity. Interestng for me: Multidimensional context representation for situational trust (Rehak, Gregor & Pechoucek, 2006). To do: deal with newcomers (first-encounter)

Preliminary Results on Reputation Systems: Balancing Quantity and Quality
Jonathan Ben-Naim

Agents in a network with a ranking that models reputation. A global measure (untractable for very large open systems as web). Two axioms: transitivity and strict transitiviy (good as first approach, but it can not be generalized). They refines the values in different interactions. What does it happend when there are loops? A lot of things to explain: ‘random’ initial ranking that he promises is not affecting to the final result (I can’t believe this), no weight/importance, the use of group size (stricti trans.) is questionable….

An Interaction-oriented Model of Trust Alignment
Andrew Koster

Well, I’ve seen this a lot of times: how to align trust concepts. Particularly, I prefer to have an standard on this part. Because we can continue with that: for example, ACL; why can’t we align ACL ontologies so the agents can speack in any language? In this case: agents share the same sintactis (about trust) and the semantics has to be aligned (what does it means to have a 0.8 confidence?) Implemented using inductive llogic programming (scalability?)

Supplier performance in a Digital Ecosystem
Angela Fabregues

Deals with partnership selection in cases where negotiation/argumentation is involved.

(Inciso: OMG bolitas paseándose por la pantalla, a DocThreeC le encantará esta plantilla ¿se lo digo? luego nos torturará).

To define the model of trust she begins with the ontology, similarity, expectations (see the invited talk of Carles Sierra this morning). By using past experiences, the probab. distribution of expected observation is modified. So, at the end, you do not take into accout the information about the exact object, but the similar ones too.

(otro inciso: ¡qué garrillas tiene la chica de las traspas! parece Ana Obregón :-D)

She continues explainig how the trust value is calculated using all these things and a bit (quickly) about similarity.

On Norm Internalization. A Position Paper
Daniel Villatoro (as guess star) in behalf of Rosaria Conte

How agents internalize existing norms and incorporates them to their behavior. He begins talking about goal internalization. At the beginnig, you behav. is directed by norms, but when yo asimilated them then you behaves in that way not to avoid a punishment, but because you want to behave in that way (for example, to stop when light is red in a semaphore). Too fast to listen and to write at the same time (you know, I’m a man), but it is a very interesting thing and I think that is related with adaptive organizations. I have to read the paper this this idea on mind. An intertesting point: urgency is a factor that affects to the speed at which intentions are internalized.

It is integrated with EMIL-A (BDI), N-Bel -> N-Goal -> N-Intentions that are Internalized as a conformed behav. A comment: this work is about people, not artificial agents.

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EUMAS 09. Session 1. Applications

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On the design of mWater: a case study for Agreement Technologies
Pablo Noriega

About how to deal with water problems, involving many stakeholder with conflicting interests. This problem is modelled using electronic institutions. My comment: I think that is importan to consider more general works. I particularly like the papers about complex social ecological systems (Ostrom 2009 and Meizen-Dick 2007 ) which combines the environment, the resources, the users and the institutions and their relationships in a complete model. eInstitutions are very useful to model the institutional part (administrations, goverment…), but a more open environment (Thomas) is needed to take into account individual users and their social relationships to create a self-adaptive subsystem. I guess that this is the correct direction to deal with this problem. The vision that Carlos, Alberto and myself propose with consensus networks is just another point of view, but all of them are important and they need to be integrated.

Detecting Anomalies in Unmanned Vehicles Using the Mahalanobis Distance
Raz Lin

A model-free method based on statistical techniques to detect anomalies so that they can be corrected on time. They apply Mahalanobis distance (it sounds to me; i think that Alberto talked us about this for consensus networks; I have to check it). Using this distance eliminates the problems that appears in multidimensional data for euclidean distances. THe problem: it does not work well with qualitative changes (even if a partial order can be artificially defined?). An you’re losing a lot of domain dependent knowledge that can be useful!!

Dynamic ontology co-construction based on adaptive multi-agent technology
Sellami Zied

A tool to help ontologists to create ontologies (Dynamo project  A bit confusing: there is another dynamo for ontologies)

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[AAMAS09] Multi-Agent Learning II. Emergent Behaviour II

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Well, well, well, finally I’m in a room

Stigmergic Landmark Foraging
Nyree Lemmens, Karl Tuyls

Late

Integrating Organizational Control into Multi-Agent Learning
Chongjie Zhang, Shereif Abdallah, Victor Lesser

Problems of distributed learning

  1. 1
  2. 2
  3. 3

Basic idea: organisational-based supervision framework. It’s a multilevel structure (recursive?) Lowest level network agents are ‘workers’. Each leaning agent reposrt its abstract state to its inmediate supervisor and them use rules a suggestions to transmit its supervisory informatio to its subordinates. Rules are set of forbidden actions and suggestions are actions with a degree in [-1,1], Rules are hard constraints and sugg are soft constraints that represent preferences.

The problem they’ve used to test this model is DTAP (distributed task allocation problem). Using a 27×27 agent grid… only!!!, too small!! I can manage several millions of agents to do the same :-( The results: interesting, but I don’t
understand all this stuff to be used in a small network as this: two supervision levels for such a group of agents.

It scales, but adding more supervision levels that may affect to the performance. I don’t like it. You’ll need a lot of layers for a really big network. Furthermore, in the experiments they’ve used a grid instead of a network and this is not ‘elegant’.

Multiagent Learning in Large Anonymous Games
Ian Kash, Eric Friedman, Joseph Halpern

We need to learn quickly, with minimal information and despite of noise. And to test their method they’re using games, but instead of being game theoretic games, they’re continuous, anonymous and designed games. He explains the method with a simple game but at the end it’s similar to game theory… I hate utility functions for agents. The behaviour can’t be reduced to a number or a function. Agents are more complex that that. We are more complex than that.

A simple algorithm to adapt the agent’s behaviour to the rest, so the dynamic converge despite of having agents making mistakes (so they’re introducing noise) in their decisions. As the number of agents increases, the system is more stable and converges faster… they’ve tried with 100 agents (again, too small for me). This results allows to tolerate strange behaviours.

Learning of Coordination
Francisco Melo, Manuela Veloso

Problem: many MAS solutions assume full joint sate observability because consider only local observability makes the problem too complex to be solved. But in many of these problems agent interactions are local. So they have to learn when interaction/coordination is advantageous. MDP and Q-learning is useed. And to show how it works, with an example of two robots that have to cross a gate.

They introduce a Coordination action (pseudo-action) and agents have to decide when to use this Coord action (it has a small penalty). Interesting method: agents can decide when to coordinate instead of exchange irrelevant messages all the time. They’ve tried with many different scenarios.

Abstraction Pathologies in Extensive Games
Kevin Waugh, Dave Schnizlein, Michael Bowling, Duane Szafron

Talking about poker competition for agents. Just two-playesrs. They use abstractions and the agent has to decice when to refine. Test with no-limit and leduc hold’em (small game, 6 cards deck, one ard ‘hidden’ and the other public). Boring… talking about the details of the game and many, many results.

State-Coupled Replicator Dynamics
Daniel Hennes, Karl Tuyls

Using evolutionary game theory, but it is single state dynamic, so it has to be extended to multi-state. Showing the behaviour in different classic games (as Prisoner’s Dilemma). Definitely…. i’m not interesting on this at all.

Wait a minute, with the examples I’ve seen hat it’s very similiar to our model of agreement, at least how it behaves. I’ll need to take a look to it. Too formal, but I hope that Alberto could help us with this.

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AAMAS09 MABS and emergent behaviour

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This is my first ‘normal session’ in the AAMAS. Yesterday we had a very boring poster session: three hours standing up just to talk 10 mins. with 4 people :-( And today an stressing morning with 6 parallel sessions Impossible to attend the all the topics I’m interested in.

On the Significance of Synchroneity in Emergent Systems
Adam Campbell, Annie Wu

I’ve arrive late, so I’m only trying to get a chair.

On Recursive Simulation
Latek Maciej, Rob Axtell, Bogumil Kaminski

Using something calles n-th order rationality (I haven’t the foggiest idea about what it is). Oh!, it’s about rationality in games (I don’t like game theory and any utility-based solution). They have a tactical model (that represents the evolution of the environment, without decision making information from other agents). So only the ‘trajectories’ of the policies can be found, nor the policies themselves. A n-th order rationality is defined recursively and… ups, too fast… he’s in the example now :-( playing Blotto (I don’t know this game). He’s talking about cognitive capabilities but, at the end, it’s represented just by one equation. Can knowledge be reduce just to one equation?

Adaptive Learning in Complex Evolving Trade Networks
Tomas Klos, Bart Nooteboom

Motivation: task allocation in networks of trading agents, with input/aoutput relations. IN classical economics, individual nodes are optimized, whereas transaction costr economics is focus on transactions (edges). Agents are rational and opportunistic. Buyers choose make or buy something and it’s implemented using Gale-Shapley algorithm for matching (game theory again… maybe the title of this session is wrong), using preferences based on scores related with potential profit and some trust (loyalty) measure.

Some experimental results, that turn into something interesting when they begin to consider the network itself, at least the indegree and outdegree (4 max. with a random network I guess). So, they have a model to simulate organizations using agents to check hypothesis.

A Mathematical Analysis of Collective Cognitive Convergence
Van Parunak

The idea of CCC is intgeresting: how a ‘closed’ collective can ‘corrupt’ the knowledge being something ‘endemic’. And they’re using agents-based models to explain why this is happening. They have simulated that and now they have a formal model of all this stuff.

An interesting result in theorem 4: it detects when the system converges (non deseable), so it can be corrected. And this convergence depends on number of agents, the number of topics and the topic’s density.

Emergent Service Provisioning and Demand Estimation through Self-Organizing Agent Communities
Mariusz Jacyno, Seth Bullock, Michael Luck, Terry Payne

A simulation model to match supply with demand in service based communities (coalitions and teams). Very difficult to synchronise choices in a centralised way and it leads to over-provisioning of services (againt a reason to create a distributed SF federation and, why not,  using a small world model ;-) This work is based on the emergent behaviour of insect colonies (OMG, ants again!) -> limited knowledge about peers and local behaviour (it sounds to me).

One interesting idea: to change the type of a provided service  has a cost, a penalty, so the system trends to keep the services unchanged as long as possible. Besides, resources are limited so a limited-size registry of known providers are maintained by customers, whereas providers have a limited-seize registry of user’s requests.

The simulation considers the amount of memory and only two types of services are available. When you have too few or too much memory the performance is worse that in a medium case, where you know enough providers/customers to work locally without service changes.

Effective Tag Mechanisms for Evolving Cooperation
Matthew Matlock, Sandip Sen

The last one, about considering expertise in a agent network using tag mechanism. Tags are a useful mechanism to promote collaborative behavior and it allows to reuse knowledge

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Small World for Agent Search

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posteraamas09 Es el título de mi póster en el AAMAS ’09. Se trata de evaluar si es válido un modelo de red de tipo small world para distribuir a un grupo de plataformas  de agentes en una red de forma que se pueda localizar fácilmente dónde se encuentra un agente con el que nos queremos comunicar.

El modelo de red que se emplea ha sido propuesto por Kleinberg y garantiza que se pouede realizar un proceso de búsqueda voraz (tomando decisiones de forma local y sin volver atrás) acotado. A este tipo de redes se les llama redes navegables.

En un artículo más extenso lo he comparado con otros modelos de redes de tipo small world y la verdad es que sale bastante bien parado: es una red tan buena como la mejor (el modelo de Barabasi según mis pruebas) en cuanto a tolerancia a fallos (destrucción de enlaces en la red), pero mucho mejor en cuanto a la búsqueda, mejorando incluso a los modelos P2P.

Referencia

REBOLLO, M.: Small World Model for Agent Search (Short Paper).- In Proc. of 8th Int. Conf. on Autonomous Agents and Multiagent Systems (AAMAS 2009), Decker, Sichman, Sierra and Castelfranchi (eds.), May, 10–15, 2009, Budapest, Hungarytions.

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