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Dissertation

Designing and trusting multi-agent systems for B2B applications

01 Jan 2008-

TL;DR: A trust model allowing agents to evaluate the credibility of other peers in the environment using agents' credibility is proposed, which applies a number of measurements in trust evaluation of other party's likely behavior.

AbstractThis thesis includes two main contributions. The first one is designing and implementing B usiness-to-B usiness (B2B ) applications using multi-agent systems and computational argumentation theory. The second one is trust management in such multi-agent systems using agents' credibility. Our first contribution presents a framework for modeling and deploying B2B applications, with autonomous agents exposing the individual components that implement these applications. This framework consists of three levels identified by strategic, application, and resource, with focus here on the first two levels. The strategic level is about the common vision that independent businesses define as part of their decision of partnership. The application level is about the business processes, which are virtually integrated as result of this common vision. Since conflicts are bound to arise among the independent applications/agents, the framework uses a formal model based upon computational argumentation theory through a persuasion protocol to detect and resolve these conflicts. Termination, soundness, and completeness properties of this protocol are presented. Distributed and centralized coordination strategies are also supported in this framework, which is illustrated with an online purchasing case study followed by its implementation in Jadex, a java-based platform for multi-agent systems. An important issue in such open multi-agent systems is how much agents trust each other. Considering the size of these systems, agents that are service providers or customers in a B2B setting cannot avoid interacting with others that are unknown or partially known regarding to some past experience. Due to the fact that agents are self-interested, they may jeopardize the mutual trust by not performing the actions as they are supposed to. To this end, our second contribution is proposing a trust model allowing agents to evaluate the credibility of other peers in the environment. Our multi-factor model applies a number of measurements in trust evaluation of other party's likely behavior. After a period of time, the actual performance of the testimony agent is compared against the information provided by interfering agents. This comparison process leads to both adjusting the credibility of the contributing agents in trust evaluation and improving the system trust evaluation by minimizing the estimation error.

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Citations
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Journal Article
Henry Prakken1
Abstract: This article investigates to what extent protocols for dynamic disputes, i.e., disputes in which the information base can vary at different stages, can be justified in terms of logics for defeasible argumentation. First a general framework is formulated for dialectical proof theories for such logics. Then this framework is adapted to serve as a framework for protocols for dynamic disputes, after which soundness and fairness properties are formulated or such protocols relative to dialectical proof theories. It then turns out that certain types of protocols that are perfectly fine with a static information base, are not sound or fair in a dynamic setting. Finally, a natural dynamic protocol is defined for which soundness and fairness can be established.

10 citations


Dissertation
01 Jan 2009
TL;DR: The designing and specification of a trust and contextual information aggregation model, intended to be a reliable alternative to the trust aggregation models already existing, and trying to set apart from those by including rules to emulate human common sense regarding trust building, and mechanisms to obtain a recommendation grade concerning how likely is a potential partner to perform as the authors desire in the fulfilment of a given contract.
Abstract: The study of trust aggregation mechanisms to assist the selection of companies in Business-to-Business systems, is becoming increasingly important to researchers in the areas of Multi-Agent Systems and Electronic Business, because it has been proved that it can provide means to increase the performance and reliability of the existing electronic business communities, by endowing them with human-like social defence mechanisms. The study we present in this document concerns the designing and specification of a trust and contextual information aggregation model, intended to be a reliable alternative to the trust aggregation models already existing, and trying to set apart from those by including rules to emulate human common sense regarding trust building, and mechanisms to obtain a recommendation grade concerning how likely is a potential partner to perform as we desire in the fulfilment of a given contract. This dissertation has three main parts. In the first, we present the trust and contextual information model, showing how we use an S-shaped curve to aggregate the past contract results of a given entity. From there we can retrieve a degree of trust which represents, in an abstract and simplified way, how likely is a given entity to fulfil the next contract, given how well she fulfilled the previous ones. The aggregation of contextual information can act as a disambiguation tool, because the information of the past contracts is treated concerning the context in which they were celebrated, providing, this way, a mean to assess if a given company is the most adjusted to do business with, regarding the specificities of the contract, and independently of how much trust do we deposit in them. In the second part we specify the application that we developed to simulate the process of company selection. This application implements the models that we propose as solution together with a third one, developed by another research group, to compare the performance and utility of our model. We simulate a fabric market, in which a group of buyers needs to buy certain quantities from sellers. In this process, each buyer is going to need the degree of trust and the degree of recommendation for each candidate seller, deciding which one(s) to buy from depending on that information. In the third part we demonstrate and analyze the results that we got from the simulations we have made. We developed three kinds of validation tests for the models: how fast were they identifying the companies violating fewer contracts, how well they react to an abrupt company behaviour change, and how much will the use of a recommendation grade affect the process of selecting a business partner. The results we got from the simulations show that our system for trust and contextual information measure represents a reliable option as a trust aggregation models, since, when compared to other model, it proves to be capable of selecting more times the best business partner, which understandably ends up in fewer violated contracts by the selected seller and higher business utility for the buyer.

References
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Book
01 Jan 1944
Abstract: This is the classic work upon which modern-day game theory is based. What began more than sixty years ago as a modest proposal that a mathematician and an economist write a short paper together blossomed, in 1944, when Princeton University Press published "Theory of Games and Economic Behavior." In it, John von Neumann and Oskar Morgenstern conceived a groundbreaking mathematical theory of economic and social organization, based on a theory of games of strategy. Not only would this revolutionize economics, but the entirely new field of scientific inquiry it yielded--game theory--has since been widely used to analyze a host of real-world phenomena from arms races to optimal policy choices of presidential candidates, from vaccination policy to major league baseball salary negotiations. And it is today established throughout both the social sciences and a wide range of other sciences.

19,323 citations


Book
01 Jan 1994
Abstract: A Course in Game Theory presents the main ideas of game theory at a level suitable for graduate students and advanced undergraduates, emphasizing the theory's foundations and interpretations of its basic concepts. The authors provide precise definitions and full proofs of results, sacrificing generalities and limiting the scope of the material in order to do so. The text is organized in four parts: strategic games, extensive games with perfect information, extensive games with imperfect information, and coalitional games. It includes over 100 exercises.

7,012 citations


Book
01 Jan 1969
Abstract: Part I. A Theory of Speech Acts: 1. Methods and scope 2. Expressions, meaning and speech acts 3. The structure of illocutionary acts 4. Reference as a speech act 5. Predication Part II. Some Applications of the Theory: 6. Three fallacies in contemporary philosophy 7. Problems of reference 8. Deriving 'ought' from 'is' Index.

6,825 citations


Book
12 Jun 2002
TL;DR: A multi-agent system is a distributed computing system with autonomous interacting intelligent agents that coordinate their actions so as to achieve its goal(s) jointly or competitively.
Abstract: The study of multi-agent systems (MAS) focuses on systems in which many intelligent agents interact with each other. These agents are considered to be autonomous entities such as software programs or robots. Their interactions can either be cooperative (for example as in an ant colony) or selfish (as in a free market economy). This book assumes only basic knowledge of algorithms and discrete maths, both of which are taught as standard in the first or second year of computer science degree programmes. A basic knowledge of artificial intelligence would useful to help understand some of the issues, but is not essential. The books main aims are: To introduce the student to the concept of agents and multi-agent systems, and the main applications for which they are appropriate To introduce the main issues surrounding the design of intelligent agents To introduce the main issues surrounding the design of a multi-agent society To introduce a number of typical applications for agent technology

4,040 citations


Journal ArticleDOI
TL;DR: By showing that argumentation can be viewed as a special form of logic programming with negation as failure, this paper introduces a general logic-programming-based method for generating meta-interpreters for argumentation systems, a method very much similar to the compiler-compiler idea in conventional programming.
Abstract: The purpose of this paper is to study the fundamental mechanism, humans use in argumentation, and to explore ways to implement this mechanism on computers. We do so by first developing a theory for argumentation whose central notion is the acceptability of arguments. Then we argue for the “correctness” or “appropriateness” of our theory with two strong arguments. The first one shows that most of the major approaches to nonmonotonic reasoning in AI and logic programming are special forms of our theory of argumentation. The second argument illustrates how our theory can be used to investigate the logical structure of many practical problems. This argument is based on a result showing that our theory captures naturally the solutions of the theory of n-person games and of the well-known stable marriage problem. By showing that argumentation can be viewed as a special form of logic programming with negation as failure, we introduce a general logic-programming-based method for generating meta-interpreters for argumentation systems, a method very much similar to the compiler-compiler idea in conventional programming. Keyword: Argumentation; Nonmonotonic reasoning; Logic programming; n-person games; The stable marriage problem

4,022 citations