547 research outputs found

    Opportunistic Reasoning for the Semantic Web: Adapting Reasoning to the Environment

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    Despite the efforts devoted so far, the Semantic Web vision appears to be an eluding target. We propose a paradigm shift for the Semantic Web centred around the pragmatics of developing Semantic Web applications in order to overcome the bootstrapping problem it suffers from. This paradigm is based on the vision of the Semantic Web as the result emerging from the integration and collaboration of a plethora of Semantic Web applications, rather that as a global entity. On the basis of this assumption we describe and propose Opportunistic Reasoning as a general purpose reasoning model suitable for the development of reasonably scalable Semantic Web applications

    Hi-Val: Iterative Learning of Hierarchical Value Functions for Policy Generation

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    Task decomposition is effective in manifold applications where the global complexity of a problem makes planning and decision-making too demanding. This is true, for example, in high-dimensional robotics domains, where (1) unpredictabilities and modeling limitations typically prevent the manual specification of robust behaviors, and (2) learning an action policy is challenging due to the curse of dimensionality. In this work, we borrow the concept of Hierarchical Task Networks (HTNs) to decompose the learning procedure, and we exploit Upper Confidence Tree (UCT) search to introduce HOP, a novel iterative algorithm for hierarchical optimistic planning with learned value functions. To obtain better generalization and generate policies, HOP simultaneously learns and uses action values. These are used to formalize constraints within the search space and to reduce the dimensionality of the problem. We evaluate our algorithm both on a fetching task using a simulated 7-DOF KUKA light weight arm and, on a pick and delivery task with a Pioneer robot

    The RACE Project: Robustness by Autonomous Competence Enhancement

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    This paper reports on the aims, the approach, and the results of the European project RACE. The project aim was to enhance the behavior of an autonomous robot by having the robot learn from conceptualized experiences of previous performance, based on initial models of the domain and its own actions in it. This paper introduces the general system architecture; it then sketches some results in detail regarding hybrid reasoning and planning used in RACE, and instances of learning from the experiences of real robot task execution. Enhancement of robot competence is operationalized in terms of performance quality and description length of the robot instructions, and such enhancement is shown to result from the RACE system

    Features for Killer Apps from a Semantic Web Perspective

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    There are certain features that that distinguish killer apps from other ordinary applications. This chapter examines those features in the context of the semantic web, in the hope that a better understanding of the characteristics of killer apps might encourage their consideration when developing semantic web applications. Killer apps are highly tranformative technologies that create new e-commerce venues and widespread patterns of behaviour. Information technology, generally, and the Web, in particular, have benefited from killer apps to create new networks of users and increase its value. The semantic web community on the other hand is still awaiting a killer app that proves the superiority of its technologies. The authors hope that this chapter will help to highlight some of the common ingredients of killer apps in e-commerce, and discuss how such applications might emerge in the semantic web

    How research on language evolution contributes to linguistics

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    Since its inception in the second part of the 20th century, the science of language evolution has been exerting a growing and formative pressure on linguistics. More obviously, given its interdisciplinary character, the science of language evolution provides a platform on which linguists can meet and discuss a variety of problems pertaining to the nature of language and ways of investigating it with representatives of other disciplines and research traditions. It was largely in this way that the attention of linguists was attracted to the study of emerging sign languages and gestures, as well as to the resultant reflection on the way different modalities impact communicative systems that use them. But linguistics also benefits from the findings made by language evolution researchers in the context of their own research questions and methodologies. The most important of these findings come out of the experimental research on bootstrapping communication systems and the evolution of communicative structure, and from mass comparison studies that correlate linguists data with a wide range of environmental variables
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