María José Santofimia Romero - Grupo ARCO - Universidad de ...

challenging requirements that have to be tackled when developing systems for Ambient Intelligence[113].As already stated above, an additional difficulty in developing Ambient Intelligence systems isthat of having to cope with the wide range of device technologies that populate these environments.Device capabilities to cooperate and interact among themselves are inherent to the Ambient Intelligenceparadigm. However, it cannot be forgotten that low-level details concerning communicationprotocols, operating systems, or programming languages, etc., are overlooked aspects that hamperseamless cooperation among devices. This concern has been addressed, with different levels of success,by a wide variety of techniques, such as web services [71], middleware [55] [16], dynamicreconfiguration [17], agents [18], context modeling or reasoning approaches [116] [103] among themost relevant ones.Along with the device heterogeneity feature, it is also worth remembering that device continuitycannot be taken for granted. On the contrary, electronic devices are constantly appearing and vanishingfrom the scene. For example, the appearance of a person that holds a cell phone should alsomeans that a new device is being offered new services. Whenever the person abandons the supervisedspace, the cell phone stops providing services. The main implication of this discontinuity in theservice availability is that environmental responses cannot be statically pre-coded as service instantiationrecipes. On the contrary, systems for Ambient Intelligence are expected to devise in an ad-hocmanner the most appropriate means to undertake a specific purpose.The purpose of these introductory paragraphs has been to provide the reader with a clear idea ofthe unresolved challenges that are preventing Ambient Intelligence from being a reality. The conclusionthat can be drawn from this initial analysis, which also serves as the initial working hypothesisof this thesis, is that the autonomy expected from Ambient Intelligence systems can only be achievedby leveraging cognitive and behavioral human-like capabilities. In this respect, in the late 60’s Mc-Carthy postulated in [87] that only by endowing programs with common sense could they be able toachieve the intelligence sought. Doug Lenat in [80] also pointed in the same direction, highlightingthe importance that common-sense knowledge has when dealing with and reacting to novel situations.The agreement on the key role that common sense plays in building intelligent systems is oneof the axiomatic facts of this thesis. Efforts are therefore addressed to enact common-sense knowledgeand reasoning capabilities as a prerequisite to support the cognitive and understanding processesdemanded by Ambient Intelligence.Additionally, understanding processes are also dependent on the capacity to perform causal explanationsof the facts, which come in the shape of sensor values, retrieved from the environment.According to Davidson [30], the reason that motivates an action also rationalizes it, and therefore, thisthesis is also grounded in the working hypothesis that an appropriate philosophy of actions should beadopted so as to support the aforementioned cognitive and understanding demands.Contrary to the current practices found in the literature review, Ambient Intelligence systemsshould be grounded in a philosophy of actions that does not respond to the convenience of the implementedapproach, but rather it does respond to the conclusions drawn from the philosophical doctrine,regarding actions, events, and reasons. The models surveyed in [121] bring to light the different characterizationof the notion of event, action, or service depending on the targeted context. This thesis isrooted in the belief that the semantic model should be unique and grounded in a rational explanationof actions and events.Summarizing the aforementioned axioms and working hypotheses, the problem of building systemsfor Ambient Intelligence has to be tackled from both the cognitive and behavioral perspectives.Additionally, the proposed solution should be built upon the basis of a semantic model for actions7