C-IPS: Specifying decision interdependencies in negotiations

Abstract. Negotiation is an important mechanism of coordination in multiagent systems. Contrary to early conceptualizations of negotiating agents, we believe that decisions regarding the negotiation issue and the negotiation partner are equally important as the selection of negotiation steps. Our C-IPS approach considers these three aspects as separate decision processes. It requires an explicit specification of interdependencies between them. In this article we address the task of specifying the dynamic interdependencies by means of IPS dynamics. Thereby we introduce a new level of modeling negotiating agents that is above negotiation mechanism and protocol design. IPS dynamics are presented using state charts. We define some generally required states, predicates and actions. We illustrate the dynamics by a simple example. The example is first specified for an idealized scenario and is then extended to a more realistic model that captures some features of open multiagent systems. The well-structured reasoning process for negotiating agents enables more comprehensive and hence more flexible architectures. The explicit modeling of all involved decisions and dependencies eases the understanding, evaluation, and comparison of different approaches to negotiating agents.

Arms Race Within Information Ecosystems

Interacting agents of exploiters and users within an information ecosystem may be regarded both as biological beings and as part of an economic system of infohabitants. A protection system can be implemented as a filter governing the access to assets. Typically we will have a chain of attacks and countermeasures concerning this access to the desired assets. We model this process as an arms race. We base our model on a process model of a protection system based on exposure time. A user's reaction against an exploiter measure could either be a direct response to the measure or an attempt to anticipate future attacks by more general means of defeating the protection of the exploiter agent. When anticipating future attacks and countermeasures, both users and exploiters will improve their methods and tools due to an arms race. Our arms race model refines the competition as modeled in computational markets to model aspects which typically arise when societies grow beyond what can be controlled in a centralized manner. A dynamic, evolving and robust ecosystem of autonomous agents is sometimes a preferred and possible outcome of the arms race as a hardening process

Multiagent Matching Algorithms with and without Coach

A matching is a (one-to-one) mapping between two sets, satisfying some given constraints. In

Auctions with Arbitrary Deals

To come to a deal, a bargaining process can sometimes take a long time. An auction may be a faster, but existing auction models cannot cope with situations where money is not an issue, or where it is difficult to express the utility of all participants in a monetary domain. We propose a modified Vickrey auction based only on preferences over the possible bids. This approach also allows for situations where a bid is not just a price or some fixed set of attributes, but can be any possible offer. We prove that in this flexible, generalized setting, the Vickrey mechanism is still incentive compatible and results in a Pareto-efficient solution.Software Computer TechnologyElectrical Engineering, Mathematics and Computer Scienc

Influencia de las aleaciones metálicas en el color de la cerámica

El efecto cromático final de las restauraciones metalo-cerámicas se ve influenciado por el tipo de aleación metálica usada en su realización. En este estudio hemos realizado un análisis calorimétrico de 50 especímenes donde se combinan dos colores y cinco aleaciones diferentes. Después del análisis estadístico pertinente, se ha concluido que las aleaciones de base paladio plata son las que producen una variación más notoria del color, aumentando la saturación de amarillo y verde