Interaktive Visualisierung und Simulation zur Planung chirurgischer Eingriffe

Zusammenfassung. Der vorliegende Artikel beschreibt aktuelle Ans?tze zur Visualisierung und weiteren Bearbeitung medizinischer Volumendaten. Die Methodik verfolgt das Ziel, die pr?operative Planung chirurgischer Eingriffe zu unterstützen, in dem Volumendaten interaktiv visualisiert und Gewebe wie auch funktionelle Einheiten simuliert werden. Eingebettet in ein Radiologiesystem kann der Benutzer mit den Visualisierungen im dreidimensionalen Raum interagieren. Ein hybrider Ansatz erlaubt die Integration von oberfl?chen- und volumenorientierten Objektmodellen. Die Client/Server Architektur erlaubt die Nutzung zentraler, leistungsf?higer Ressourcen zur Berechnung der Volumenvisualisierung und Methoden der Bildverarbeitung. Eingegangen am 11. Juli 1998 / Angenommen am 7. Januar 1999     

Konfiguration komplexer Produkte mit Constraint-basierter Modellierung

Zusammenfassung.   Industrielle Konfigurationsprozesse sind, bedingt durch die vorherrschende Variantenvielfalt, sehr komplex. Aufgrund der inh?renten Potentiale ist die Realisierung von effizienten, flexiblen Konfigurationsprozessen ein zentrales Ziel vieler Unternehmen. Wir haben einen Ansatz für die Konfiguration und Rekonfiguration von Produkten entwickelt, der auf Constraint-basierter Modellierung über endlichen Dom?nen basiert. Das auf diesem Ansatz beruhende System ConBaCon deckt eine breite Palette von Konfigurationsproblemen ab und erm?glicht eine effiziente L?sung, die sowohl automatisch als auch gesteuert durch hoch flexible Nutzerinteraktion erfolgen kann. Wendet man das System jedoch auf gro?e Konfigurationsprozesse an, so treten Performanzprobleme auf. Als zwei wesentliche Modellerweiterungen, die diesem Mangel entgegenwirken, stellen wir in dieser Arbeit einerseits eine Modell-Clusterung und andererseits die Behandlung gro?er Netze arithmetischer Constraints vor. Eingegangen am 11. Februar 2002 / Angenommen am 18. Juli 2002     

Architektur Multimedialer Informationssysteme

Ohne Zusammenfassung

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Architektur Multimedialer Informationssysteme

     

Integration of New Exercise Classes into the Informatics Education in the Field of Object-Oriented Modelling

In secondary informatics education in Germany in the field of object-oriented modelling (OOM) a lack of published suitable learning material focussing on modelling instead of programming was found. This especially holds for learner adequate exercises on OOM. In this paper methods for identifying exercise classes by specialist textbook analysis, for structuring exercise classes in a catalogue and for designing learner adequate exercises are proposed with the aim to help teachers create exercises and give learners orientation in combining abstract exercise classes with solution strategies. Based on a first version of an OOM exercise class catalogue, exploratory tests were performed in secondary informatics education (analysis of filled in worksheets with OOM exercises), informatics teacher education (design of exercises) and in-service teacher training. The results led to a refinement of the concept. In summarizing educational experiences exercise classes give learners a promise for probable educational success.     

On discriminating temporal relations: Is it relational?

Pigeons were presented on each trial with a pair of keylight stimuli that varied in duration. One of two subsequent choices was reinforced, depending on which of the two stimuli was longer. For some pairs, the duration of one stimulus was predictive of relative duration, but for other pairs, absolute duration was unpredictive. Choice responses depended on relative differences between the stimuli, but were also controlled to some degree by absolute duration of the second member of the pair. Individual differences in control by absolute and relative duration were evident. Those pigeons whose behavior was most influenced by absolute duration showed poorer transfer to a different set of duration pairs.     

The idea of the university

Professor Emeritus of International Education at the University of Stock-holm and President of the International Academy of Education. Former Director of the Institute of Educational Research (1971–82), chairman of the Governing Board of the International Institute for Educational Planning (1970–80) and Chairman of the International Association for the Evaluation of Educational Achievement (1962–78). He is the author of some fifty books and hundreds of articles.     

Same-different comparison of duration

Pigeons were trained on a task in which a red light of durationt ₁ was followed by a green light of durationt ₂ and then responses to different keys were reinforced according to whether the durations of the stimuli were the same or different. For Experiment 1, duration pairs consisted of all combinations of 1, 2, 4, and 8 sec. In Experiment 2,different-duration pairs included only combinations witht ₁ >t ₂ and, in addition, 2 subjects with extended training involving lesser-greater duration comparisons were transferred to the same-different task. Two of 3 subjects learned the task in Experiment 1 and analyses suggested that choices were based on specific instances, not on a temporal same-different rule. All 5 birds acquired the discrimination in Experiment 2, where it appeared that choices were controlled by a combination of relative and absolute rules. Accuracy decreased following transfer from a lesser-greater to a same-different discrimination, but performance was above chance on the first transfer session. In both experiments, however, accuracy was below that found in earlier work with lesser-greater comparisons of duration. These findings are discussed in relation to prior research with lesser-greater comparisons of duration and same-different tasks involving nontemporal stimuli.