25 research outputs found

    An alternative proof method for possibilistic logic and its application to terminological logics

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    Possibilistic logic, an extension of first-order logic, deals with uncertainty that can be estimated in terms of possibility and necessity measures. Syntactically, this means that a first-order formula is equipped with a possibility degree or a necessity degree that expresses to what extent the formula is possibly or necessarily true. Possibilistic resolution, an extension of the well-known resolution principle, yields a calculus for possibilistic logic which respects the semantics developed for possibilistic logic. A drawback, which possibilistic resolution inherits from classical resolution, is that it may not terminate if applied to formulas belonging to decidable fragments of first-order logic. Therefore we propose an alternative proof method for possibilistic logic. The main feature of this method is that it completely abstracts from a concrete calculus but uses as basic operation a test for classical entailment. If this test is decidable for some fragment of first-order logic then possibilistic reasoning is also decidable for this fragment. We then instantiate possibilistic logic with a terminological logic, which is a decidable subclass of first-order logic but nevertheless much more expressive than propositional logic. This yields an extension of terminological logics towards the representation of uncertain knowledge which is satisfactory from a semantic as well as algorithmic point of view

    Towards a Semantic Portal for Oncology using a Description Logic with Fuzzy Concrete Domains

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    This paper presents three systems that are fully implemented and a proposal for a fourth one. KASIMIR is a knowledge based-system using an ad hoc formalism similar to a simple description logic with concrete domains which is used for representing decision protocols in oncology. FUZZY-KASIMIR is an extension of KASIMIR with fuzzy concrete domains taking into account discontinuities in the decision that are due to numerical thresholds. Another extension of KASIMIR has led to embed it into a semantic portal for oncology, which has been motivated by the need to share knowledge for geographically distributed physicians and has led to change the ad hoc formalism to the standard OWL DL. A combination of these two extensions of KASIMIR is currently under implementation and will lead to a semantic portal for oncology with fuzzy datatypes

    Verbmobil : translation of face-to-face dialogs

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    Verbmobil is a long-term project on the translation of spontaneous language in negotiation dialogs. We describe the goals of the project, the chosen discourse domains and the initial project schedule. We discuss some of the distinguishing features of Verbmobil and introduce the notion of translation on demand and variable depth of processing in speech translation. Finally, the role of anytime modules for efficient dialog translation in close to real time is described

    Uncertainty and the Semantic Web

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    Abschlußbericht des Arbeitspaketes PROD

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    In dieser Studie wird eine Übersicht über konventionelle Produktmodelle im Bereich des Maschinenbaus gegeben. Es werden Datenstrukturierungs- und speicherungsaspekte diskutiert. Die Erkenntnisse sollen eine Grundlage für die Erstellung eines integrierten wissensbasierten Produktmodelles werden

    Towards Contingent World Descriptions in Description Logics

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    The philosophical, logical, and terminological junctions between Description Logics (DLs) and Modal Logic (ML) are important because they can support the formal analysis of modal notions of ‘possibility’ and ‘necessity’ through the lens of DLs. This paper introduces functional contingents in order to (i) structurally and terminologically analyse ‘functional possibility’ and ‘functional necessity’ in DL world descriptions and (ii) logically and terminologically annotate DL world descriptions based on functional contingents. The most significant contributions of this research are the logical characterisation and terminological analysis of functional contingents in DL world descriptions. The ultimate goal is to investigate how modal operators can – logically and terminologically – be expressed within DL world descriptions

    Multimedia presentations : the support of passive and active viewing

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    In contrast to conventional printed text which allows for passive viewing only, computer-based presentations can support various forms of user interaction and let the user play an active part at presentation time. As each presentation style has its own strengths and weaknesses, we aim at a multimedia presentation system that supports both passive and active viewing of the generated material. We start from our previous work on the plan-based synthesis of multimedia presentations where all presentation acts have been planned and realized by the system. However, in the approach presented in this paper, we allow certain presentation acts to be planned and/or realized by the user as well. We augment structuring principles for non-interactive multimedia presentations and integrate them into a uniform framework. Finally, we sketch how modules of WIP, our existing presentation system, can be reused and extended

    Eine Untersuchung kommerzieller Terminverwaltungs-Software im Hinblick auf die Kopplung mit natürlichsprachlichen Systemen

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    Das Projekt COSMA (Cooperative Schedule Management Agent) verfolgt das Ziel, einen maschinellen Sekretariatsassistenten zu erstellen, der Termine mit mehreren Teilnehmern über elektronische Post in natürlicher Sprache weitgehend selbständig vereinbart. COSMA stellt natürlichsprachlichen Service für autonome maschinelle Terminplanungs-Agenten zur Verfügung. Eine Anbindung an unterschiedliche kommerzielle Softwareprodukte zur Terminverwaltung könnte die Generalisierbarkeit der in COSMA verfolgten Ansätze nachhaltig plausibel machen. In der hier dokumentierten Untersuchung wurden im Zeitraum März bis Mai 1995 auf dem deutschen Markt befindlichen Produkte untersucht und bewertet. Einige ermöglichen den Zugang zu ihren Termindaten über eine allgemeine Programmierschnittstelle; doch keines stellt Agentenfähigkeit zur Verfügung: Alle Planungs-und Entscheidungsvorgänge bleiben dem Benutzer überlassen. Eine Einbindung in COSMA ist in vielen Fällen technisch möglich, aber erst nach Entwicklung und Einbindung geeigneter Agentensysteme sinnvoll.The project COSMA (Cooperative Schedule Management Agent) is developing a machine secretarial assistent, that can autonomously schedule appointments with several participants via electronic mail in natural language. COSMA provides natural language service for autonomous appointment scheduling machine agents. Adaptation of different commercial software products for appointment management could support the claim of generality of the approaches pursued within COSMA. The study described in this document includes products available on the German market between March and May 1995. Some allow access to their appointment data via an application program interface, but no one provides any agent functionality; i.e. all planning and decision making is left to the user. For some systems, adaptation to COSMA is possible technically, but seems meaningful only after developing and adapting suitable agent systems

    Von Textgeneratoren zu Intellimedia-Präsentationssystemen

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    Während Textgeneratoren ausschließlich auf das Medium Sprache zurückgreifen, nutzen Intellimedia-Präsentationssysteme die individuellen Stärken unterschiedlicher Medien, wie Text, Graphik, Gestik und Animation, für die Informationsdarbietung. Die aus kommunikationstheoretischer Sicht allgemeinere Aufgabe wirft einerseits neue interessante Probleme auf, etwa die Selektion und die Koordination von Medien, führt aber andererseits zu einer umfassenderen Behandlung von Fragestellungen, die bereits von der Textgenerierung her bekannt sind. Dieses Papier stellt die erste Generation von sprachverarbeitenden Intellimedia Präsentationssystemen vor, skizziert die neuen Problemstellungen und beschäftigt sich insbesondere mit der Frage, inwiefern sich Methoden zur Textgenerierung verallgemeinern lassen, damit sie für die Informationspräsentation mit mehreren Medien anwendbar sind.While text generators exclusively rely on a single medium, intellimedia presentation systems take advantage of the individual strength of several media, such as text, graphics, gestures and animations, to present information. On the one hand, new interesting problems arise in the broader context of multimedia communication, in particular the selection and the coordination of media. On the other hand, this research leads to a more general treatment of problems already known from text generation. The paper discusses the first generation of NL processing intellimedia presentation systems and sketches the new problems. Particular emphasis is given to the question of how to generalize methods for text generation in such a way that they become useful for the production of multimedia presentations, too
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