https://ir.unisa.ac.za/handle/10500/23897 2026-05-05T14:12:17Z https://ir.unisa.ac.za/handle/10500/24407 A Java client/server system for accessing arbitrary CANopen fieldbus devices via the Internet Buhler, D; Nusser, G; Gruhler, G; Kuchlin, W This paper describes the Java CAN API a portable and extensible application interface to arbitrary CANopen fieldbus devices. This API forms the basis for the implementation of JRCC (Java Remote CAN Control), a tool which can be used to retrieve and modify the whole set of status parameters of arbitrary CANopen devices via the Internet, providing the basic facilities for remote maintenance, remote data acquisition and remote control of CANopen nodes. In an educational context this opens up the opportunity to demonstrate and to experience the behavior of various CANopen modules with respect to specific status modifications, independent of the local availability of those devices. Since we choose a Java client/server software architecture using TCP/IP sockets, the JRCC client can easily be embedded in an ordinary HTML web page and be executed by any web browser featuring a Java 1.1 compliant virtual machine. The abandonment of a middleware layer results in an extremely small and portable system with high availability and little system requirements, making this approach a candidate for both, a low cost embedded system solution for remote access to CANopen devices and a fieldbus teaching tool for the potentially heterogenous client system environment of a distributed collaborative learning community connected via Internet. 1999-01-01T00:00:00Z https://ir.unisa.ac.za/handle/10500/24386 An information-theoretic semantics for belief change Meyer, TA Belief change is an interdisciplinary topic and is researched in departments of Computer Science, Artificial Intelligence, Philosophy, Mathematics and Engineering. It is therefore not surprising that there are a variety of approaches to defining belief change operations. In this paper, we present an information-theoretic semantics for belief change. We argue that such a semantics has important implications when justifying both existing and newly constructed belief change operations. 1999-01-01T00:00:00Z https://ir.unisa.ac.za/handle/10500/24385 Formal verification with natural language specifications: guidelines, experiments and lessons so far Holt, A The industrial take-up of formal verification techniques remains limited. Allowing specifications to be expressed in natural language (perhaps augmented with diagrams) offers the prospect of increasing the usability of verification tools. We suggest guidelines for the development of such systems, and describe a prototype which provides an English interface to the SMV model checker by translating specification sentences to formulas of temporal logic. Limitations are discussed, and prospects for future development considered. 1999-01-01T00:00:00Z https://ir.unisa.ac.za/handle/10500/24384 Introducing a continuum of abstraction-led hierarchical search techniques Zimmer, R; Holte, R Abstraction in search works by replacing a state space by another space (the abstract space) that is easier to search, either because it is smaller or because it contains more solutions. Results of searches in the abstract space are then used to guide searches in the original space in one of two distinct ways. The first uses the lengths of the abstract solutions as a heuristic for an A* search of the original space: this always produces optimal solutions. The second uses the steps in the abstract solution as sub-goals for the search in the original space: this strategy does not guarantee optimality, but it does tend to find a solution quickly. In this paper, both of these types of abstraction-led search are explained, and a general setting for all abstraction-led search is introduced. The two standard cases are included as extreme cases in the general setting, and so are a continuum of new techniques between the two. It is hoped that further study of this continuum will lead to new, useful heuristic search techniques. 1999-01-01T00:00:00Z