The use and generation of illustrative examples in computer-based instructional systems

A method is proposed whereby the underlying domain knowledge is represented such that illustrative examples may be generated on demand. This method has the advantage that the generated example can follow changes in the domain in addition to allowing automatic customization of the example to the individual

Deployable-erectable trade study for space station truss structures

The results of a trade study on truss structures for constructing the space station are presented. Although this study was conducted for the reference gravity gradient space station, the results are generally applicable to other configurations. The four truss approaches for constructing the space station considered in this paper were the 9 foot single fold deployable, the 15 foot erectable, the 10 foot double fold tetrahedral, and the 15 foot PACTRUSS. The primary rational for considering a 9 foot single-fold deployable truss (9 foot is the largest uncollapsed cross-section that will fit in the Shuttle cargo bay) is that of ease of initial on-orbit construction and preintegration of utility lines and subsystems. The primary rational for considering the 15 foot erectable truss is that the truss bay size will accommodate Shuttle size payloads and growth of the initial station in any dimension is a simple extension of the initial construction process. The primary rational for considering the double-fold 10 foot tetrahedral truss is that a relatively large amount of truss structure can be deployed from a single Shuttle flight to provide a large number of nodal attachments which present a pegboard for attaching a wide variety of payloads. The 15 foot double-fold PACTRUSS was developed to incorporate the best features of the erectable truss and the tetrahedral truss

Wittgenstein and Davidson on actions: A contrastive analysis

This paper seeks to bring out the difference between the later Wittgenstein’s and Davidson’s view of actions with a special focus. Initially it contrasts their respective approaches to the correlative notions of wish, will (intention) and actions, an issue which has customarily been categorized as reason-approach of Wittgenstein as against the mental causation theory endorsed by Davidson. The ultimate aim of this paper is to integrate the ontology of actions with the semantic issue of the distinction between reference and description action-words, or that between the extensionalist and intensionalist approach to actions. The author demonstrates how Davidson in spite of conscientiously problematising the task of separating the mental causal antecedent from the action, goes on to undertake a hair-splitting analysis to sustain the split; and thereby preserve the extensional identity of actions. This extensional identity in Davidson’s scheme turns out to be as brute physical events with bare spatio-temporal outlines - lying beyond the various intensional ascriptions. For Wittgenstein on the other hand, actions are not caused by mental antecedents, but blend with wish, will and the so-called mental antecedents to forge an indissoluble whole, leaving no scope for the proposed bare extension to take shape. The paper concludes with a brief indication of McDowell’s treatment of this cause/reason polemics phrased in terms of the non-conceptualist versus conceptualist debate suggesting a new direction to engage with Wittgenstein’s insights on action

Learning from AI : new trends in database technology

Recently some researchers in the areas of database data modelling and knowledge representations in artificial intelligence have recognized that they share many common goals. In this survey paper we show the relationship between database and artificial intelligence research. We show that there has been a tendency for data models to incorporate more modelling techniques developed for knowledge representations in artificial intelligence as the desire to incorporate more application oriented semantics, user friendliness, and flexibility has increased. Increasing the semantics of the representation is the key to capturing the "reality" of the database environment, increasing user friendliness, and facilitating the support of multiple, possibly conflicting, user views of the information contained in a database