https://ir.unisa.ac.za/handle/10500/24120 2026-05-06T12:53:49Z 2026-05-06T12:53:49Z Philips, N.C.K. https://ir.unisa.ac.za/handle/10500/24131 2018-06-06T12:15:50Z 1986-01-01T00:00:00Z

An Alternative Development of the Vienna Data Structures Philips, N.C.K. This paper presents an axiomatic specification of a data type which is shown to be equivalent to the Vienna data structures. The advantage of this alternative approach is its obvious simplicity.

1986-01-01T00:00:00Z Mende, J. https://ir.unisa.ac.za/handle/10500/24130 2018-05-29T01:00:57Z 1986-01-01T00:00:00Z

Research directions in information systems Mende, J. The success of a research project depends upon the inputs and outputs selected by the researcher, a poor choice entailing useless results or wasted efforts.To avoid this one might consider the following alternatives: t. Our present knowledge in the subject Information Systems largely consists of facts and engineering techniques, scientific principles being few and inadequate. This imbalance suggests that research aimed at extending the scientific foundations of the subject should yield more significant results than purely technical research. 2. Structural and functional similarities between information, business and academic systems indicate the existence of general laws that apply accross the interdisciplinary boundaries of the corresponding subject areas. Accordingly it should be possible to tran~fer principles and techniques from Business and Education to Information Systems and vice versa. 3. Economic History predicts that mankind is moving towards an Edensque state in which no one is obliged to work for a living. The information systems necessary in that state therefore constitute highly significant problems for re.,;earch.

1986-01-01T00:00:00Z Finnie, G.R. https://ir.unisa.ac.za/handle/10500/24129 2018-06-06T11:46:07Z 1986-01-01T00:00:00Z

Modeller : a DSS for experimental study of Human-computer interaction Finnie, G.R. This paper describes the structure of a simple nonprocedural financial modelling system designed to collect a variety of statistics on aspects of novice interaction with decision support systems. Some findings on the use of HELP facilities by novices are discussed. Certain areas of difficulty experienced by novices are identified from an analysis of compilation and logical errors.

1986-01-01T00:00:00Z Dempster, Robert https://ir.unisa.ac.za/handle/10500/24128 2018-05-29T01:00:55Z 1986-01-01T00:00:00Z

The SECD Machine : An Introduction Dempster, Robert The S(tack), E(nvironment), C(ontrol) and D(ump) machine was invented by Landin (1964) to perform the mechanical evaluation of symbolic expressions. The evaluation of an expression invariably involves the application of an operator to an operand. The concept of an applicative expression (AE) is thus formally introduced and discussed. This is followed by an overview of the SECD machine and a detailed trace of the SECD machine state transformations during the evaluation of an AE on the SECD machine.

1986-01-01T00:00:00Z