690 research outputs found
Reasoning by analogy in the generation of domain acceptable ontology refinements
Refinements generated for a knowledge base often involve the learning of new knowledge to be added to or replace existing parts of a knowledge base. However, the justifiability of the refinement in the context of the domain (domain acceptability) is often overlooked. The work reported in this paper describes an approach to the generation of domain acceptable refinements for incomplete and incorrect ontology individuals through reasoning by analogy using existing domain knowledge. To illustrate this approach, individuals for refinement are identified during the application of a knowledge-based system, EIRA; when EIRA fails in its task, areas of its domain ontology are identified as requiring refinement. Refinements are subsequently generated by identifying and reasoning with similar individuals from the domain ontology. To evaluate this approach EIRA has been applied to the Intensive Care Unit (ICU) domain. An evaluation (by a domain expert) of the refinements generated by EIRA has indicated that this approach successfully produces domain acceptable refinements
Eyecup withdrawal in the crab, Carcinus, and its interaction with the optokinetic response
Summary
1. Protective withdrawal of the eyecup is caused by a burst of impulses in two axons of the optic tract, one to muscles 19a, 19b and 20a, the other to muscles 18, 20b, 21 and 22.
2. At a reflex eyecup withdrawal other concurrent activity is mechanically overridden ; the tonic activity in only one muscle is inhibited centrally. At a ‘spontaneous’ withdrawal, however, all motor activity to that eyecup is inhibited.
3. The largest muscle, 19a, inactive in other eyecup movements, is the prime mover in withdrawal, and some tonic fibres of this muscle hold the eyecup withdrawn.
4. Two muscles which move the eyecup toward the mid line on optokinetic responses are excited during a withdrawal. It is therefore possible for one muscle to contribute to movements in opposite directions.
5. Repeated reflex withdrawal of an eyecup moving towards the mid line inhibits the optokinetic response of the other eye.
6. Weak stimulation of an eyecup region by a variety of means, including withdrawal, improves the optokinetic response of that eyecup and sometimes of the other eyecup
Efferent copy and voluntary eyecup movement in the crab, Carcinus
At the time of publication the author was affiliated with the Gatty Marine Laboratory and Department of Natural History,
University of St Andrews, Fife, Scotland
Using Insights from Psychology and Language to Improve How People Reason with Description Logics
Inspired by insights from theories of human reasoning and language, we propose additions to the Manchester OWL Syntax to improve comprehensibility. These additions cover: functional and inverse functional properties, negated conjunction, the definition of exceptions, and existential and universal restrictions. By means of an empirical study, we demonstrate the effectiveness of a number of these additions, in particular: the use of solely to clarify the uniqueness of the object in a functional property; the replacement of and with intersection in conjunction, which was particularly beneficial in negated conjunction; the use of except as a substitute for and not; and the replacement of some with including and only with noneOrOnly, which helped in certain situations to clarify the nature of these restrictions
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