Introducing norms into practical reasoning agents
As distributed electronic systems grow to include thousands of components, from grid to peer-to-peer nodes, from (Semantic) Web services to web-apps to computation in the cloud, governance of such systems is becoming a real challenge. Modern approaches ensuring appropriate individual entities'...
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| Tipo de recurso: | tesis doctoral |
| Fecha de publicación: | 2014 |
| País: | España |
| Institución: | Universitat Politècnica de Catalunya (UPC) |
| Repositorio: | UPCommons. Portal del coneixement obert de la UPC |
| Idioma: | inglés |
| OAI Identifier: | oai:upcommons.upc.edu:2117/95474 |
| Acceso en línea: | https://hdl.handle.net/2117/95474 https://dx.doi.org/10.5821/dissertation-2117-95474 |
| Access Level: | acceso abierto |
| Palabra clave: | Agents intel·ligents (Programari) Intel·ligència artificial distribuïda Processament distribuït de dades Àrees temàtiques de la UPC::Informàtica |
| Sumario: | As distributed electronic systems grow to include thousands of components, from grid to peer-to-peer nodes, from (Semantic) Web services to web-apps to computation in the cloud, governance of such systems is becoming a real challenge. Modern approaches ensuring appropriate individual entities' behaviour in distributed systems, which comes from multi-agent systems (MAS) research, use norms (or regulations or policies) and/or communication protocols to express a different layer of desired or undesired states. From the individuals perspective, an agent needs to be able to function in an environment where norms act as behavioural restrictions or guidelines as to what is appropriate, not only for the individual but also for the community. In the literature the concept of norms has been defined from several perspectives: as a rule or standard of behaviour shared by members of a social group, as an authoritative rule or standard by which something is judged, approved or disapproved, as standards of right and wrong, beauty and ugliness, and truth and falsehood, or even as a model of what should exist or be followed, or an average of what currently does exist in some context. Currently there exist in the literature: 1) some treatments that formally connect the deontic aspects of norms with their operationalisation; 2) some treatments that properly distinguish between abstract norms and their (multiple) instantiations at runtime; 3) little work that formalises the operational semantics in a way that ensures flexibility in their translation to actual implementations while ensuring unambiguous interpretations of the norms; 4) little work that is suitable for both institutional-level norm monitoring and individual agent norm-aware reasoning to ensure that both are aligned; 5) few works that explore how the norms may affect the decision making process of an agent when the process includes planning mechanisms at runtime for means-ends reasoning. However, currently there is no work that includes both a formalism and an implementation covering 1-5 altogether. This thesis presents work towards the above five areas. We give a proposal to bridge the gap between a single norm formalisation and the actual mechanisms used for norm-aware planning, in order to create a normative practical reasoning mechanism. One way to do this is by reducing deontic-based norm definitions to temporal logic formulas which, in turn, can be translated into planning operational semantics. Based on these semantics, we create a mechanism to support practical normative reasoning that can be used by agents to produce and evaluate their plans. We construct a norm-oriented agent that takes into consideration operationalised norms during the plan generation phase, using them as guidelines to decide the agents future action path. To make norms influence plan generation, our norm operational semantics is expressed as an extension of the planning domain, acting as a form of temporal restrictions over the trajectories (plans) computed by the planner. We consider two approaches to do so. One implementing the semantics by using planning with constraints through paths and the other by directly translating the norms into domain knowledge to be included into the planning domain. We explore a scenario based on traffic laws in order to demonstrate the usability of our proposal. We also show how our normative frameworks are successfullyintegrated into an existing BDI agent implementation, 2APL. For each approach taken, we present quantitative experimental results and illustrate the opportunities for further research. |
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