https://ir.unisa.ac.za/handle/10500/24003 Wed, 06 May 2026 12:40:33 GMT 2026-05-06T12:40:33Z https://ir.unisa.ac.za/handle/10500/24057 Modelling Blocking on Admission of Tasks to Computer Systems Wulf, S. The need for modelling techniques to allow blocking of tasks prior to admission to the computer system in queueing network models is described. A detailed algorithm which presents a technique to enforce blocking by priority of class for an arbitrary number of blocking constraints is presented. The resultant solution is exact and produces an analysis by class of admission queueing delays. Sat, 01 Jan 1983 00:00:00 GMT https://ir.unisa.ac.za/handle/10500/24057 1983-01-01T00:00:00Z https://ir.unisa.ac.za/handle/10500/24056 Nebulas as Structural Data Models Van Rooyen, H.O.; Weiermans, D.J. Nebula modell_ing is_ a generalised structural modelling technique which applies to any finite set of objects (entities) and n-ary relat1onsh1ps (n ~2). A nebula model can be presented in either diagrammatic or tabular form, and combines the properties of graph (binary) data models with those of tabular (relational) data models. We give a brief introduction to nebula data modelling by means of a simple illustration. Sat, 01 Jan 1983 00:00:00 GMT https://ir.unisa.ac.za/handle/10500/24056 1983-01-01T00:00:00Z https://ir.unisa.ac.za/handle/10500/24055 An Improved Implementation of Grimbleby's Algorithm Schach, Stephen R. Details are given of an implementation of Grimbleby's algorithm for the common spanning tree problem with running times up to 50% less than for the original implementation. An explanation is given as to why implementations with even lower running times are unlikely. Sat, 01 Jan 1983 00:00:00 GMT https://ir.unisa.ac.za/handle/10500/24055 1983-01-01T00:00:00Z https://ir.unisa.ac.za/handle/10500/24054 An Analytical Model of a Mixed-Workload MVS Computer System Mann, R.J. A basic description of the facilities of the computer modelling package, AUTO-CONFIGURATER, is presented together with detailed procedures to calculate the required input parameters from monitor statistics. Techniques to calibrate the model are described together with an investigation into how the modelling package enables configuration and tuning alternatives to be evaluated. Sat, 01 Jan 1983 00:00:00 GMT https://ir.unisa.ac.za/handle/10500/24054 1983-01-01T00:00:00Z