In celebrating Arthur Prior we celebrate what he gave to the world. Much of this is measured by what others have made of his ideas after his death, and it is right that this should be so, since a philosopher’s greatness is marked by his legacy. My focus however will be a little different. I want in this talk to look at what Prior himself thought he was accomplishing. In particular I want to inv...

Querying incomplete data is an important task both in data management, and in many AI applications that use query rewriting to take advantage of relational database technology. Usually one looks for answers that are certain, i.e., true in every possible world represented by an incomplete database. For positive queries – expressed either in positive relational algebra or as unions of conjunctive...

In traditional formal approaches to knowledge representation, agents are assumed to believe all the logical consequences of their knowledge bases. As a result, reasoning in the rst-order case becomes undecidable. Since real agents are constrained by resource limitations , it seems appropriate to look for weaker forms of reasoning with better computational properties. One way to approach the pro...

To date, ontology research seems to have come to an equilibrium: there is a wide variety of theories, methods and tools for extracting, representing, storing and browsing ontologies. Furthermore, ontologies have become an integral part of many academic and industrial applications. There are, however, still deep theoretical problems to be resolved. One fundamental problem is ontology evolution. ...

In this work we look at how Fitting’s embedding of first-order classical logic into first-order S4 can help in reasoning when we are interested in satisfaction “in most cases”, when first-order properties are allowed to fail in cases that are considered insignificant. We extend classical semantics by combining a Kripke-style model construction of “significant” events as possible worlds with the...

premature chromosome condensation (pcc) appears to have a possible utility for biological dosimetry purposes. the pcc technique may be adapted for cases of suspicion of overexposure where sampling is performed at least one day after an accident. for this purpose, human blood samples were exposed in vitro to 60co up to 10 gy and the pcc technique was performed immediately after irradiation. anal...

Understanding human behaviour, and indeed human beings more generally, requires an understanding of their attitudes: their beliefs, desires and preferences of course, but also a plethora of other attitudes or attitudinal factors, such as their presuppositions, their assumptions, their intentions, their attention, their awareness and their emotional states. But people’s attitudes change over tim...

Sociocybernetics is concerned with applying theories and methods from cybernetics and the systems sciences to the social sciences by offering concepts and tools for addressing problems holistically and globally. With its distinction between first order studies of observed systems and the second order study of observing systems, sociocybernetics provides a unifying epistemological and methodolog...

Planning in belief space with a Labelled Uncertainty Graph, LUG, is an approach that uses a very compact planning graph to guide search in the space of belief states to construct conformant and contingent plans. A conformant plan is a plan that transitions (without sensing) all possible initial states through possibly non-deterministic actions to a goal state. A contingent plan adds the ability...