https://ir.unisa.ac.za/handle/10500/23895 2026-05-05T14:12:17Z https://ir.unisa.ac.za/handle/10500/25450 Computer Science and Information Systems: the future? Machanick, P 1999-01-01T00:00:00Z https://ir.unisa.ac.za/handle/10500/24323 Indexing in a case-based reasoning system for waste management Wortmann, KL; Petkov, D; Senior, E This paper presents a summary of research on indexing in Case-Based Reasoning (CBR) applied to the domain of waste management. Indexing theory and techniques are covered in order to position the results. The chosen application domain is discussed very briefly in order to demonstrate the applicability of CBR to it. Indexing techniques implemented are described and discussed. Testing methods and summarised results are discussed with respect to evaluating the success of the indexing techniques, and to identify areas of future research. 1999-01-01T00:00:00Z https://ir.unisa.ac.za/handle/10500/24322 A 3-dimensional security classification for information Smuts, W Most existing information security classification schemes use a 1-dimensional scale such as [top secret, secret, employee confidential, company confidential, restricted]. These classification schemes do not differentiate between the different security properties of information, nor between the level and the scope of security. In this paper, it is shown that a 1- dimensional classification scheme is inadequate and can result in inappropriate protection, causing increased cost and risk. A 3-dimensional security classification scheme for information is proposed and it is shown how this scheme can be used to provide adequate and appropriate levels of security. 1999-01-01T00:00:00Z https://ir.unisa.ac.za/handle/10500/24321 Orthogonal ray guarding of adjacencies between orthogonal rectangles Sanders, I; Lubinsky, D; Sears, M; Kourie, D Guarding and covering problems have great importance in Computational Geometry. In this article the notion of' a ray guard, a guard that can only 'see' along a single ray, is introduced. The problem of siting the fewest possible such guards so that they guard all adjacencies in an orthogonal arrangement of adjacent non-overlapping rectangles is discussed. The problem is farther restricted by requiring that the direction of sight be parallel to an axis and that the guards cannot 'see' outside the rectangles. The problem is motivated by applications in architecture and urban planning. This article shows that the problem is NP-Complete because of the locally indeterminate choice which can be introduced in positioning guards. 1999-01-01T00:00:00Z