South African Computer Journal - Volume 48, Issue 1, 2012
Volumes & issues
Volume 48, Issue 1, 2012
Source: South African Computer Journal 48, pp 1 –8 (2012)More Less
This paper explores the effectiveness of usage control deterrents. Usage control enables finer-grained control over the usage of objects than do traditional access control models. Deterrent controls are intended to discourage individuals from intentionally violating information security policies or procedures. In this context, an adaptation of usage control is assessed as a proactive means of deterrence control to protect information that cannot be adequately or reasonably protected by access control. These deterrents are evaluated using the design science methodology. Parallel prototypes were developed with the aim of producing multiple alternatives, thereby shifting the focus from purely usability testing to model testing.
Author Philip MachanickSource: South African Computer Journal 48 (2012)More Less
As I take over editing South African Computer Journal, it has become evident that running it on the basis of volunteers to do administration and relying on a ready team of students to handle typesetting is unsustainable. Large academic departments can absorb the costs, but that limits the number of possible candidates for the job of editor-in-chief. For this reason, as new editor-in-chief I am introducing some changes. The journal will be run with the assistance of a part-time administrator, and we will fund a bursary for a student who will be required to work on production and managing the web site.
Source: South African Computer Journal 48, pp 9 –30 (2012)More Less
The Digital Doorway (DD) is a joint initiative between the South African Department of Science and Technology (DST) and the Meraka Institute of the Council for Scientific and Industrial Research (CSIR). The DD is a non-standard computer system deployed amongst underprivileged communities in South Africa with the objective to promote computer literacy. Since its inception, there has been no usability or accessibility evaluation of the software installed on the DD, mainly due to lack of usability engineering or interaction design expertise within the development team. The goal of the research presented in this paper was to design a solution to this problem by developing a suitable instrument that could guide DD application developers in the design and development of more usable DD software and interfaces. Design research was used as a research methodology. We first investigated the applicability of the standard usability and accessibility evaluation methods for evaluating the software installed on the DD. During the first cycle of design research, we established that a heuristic-like evaluation method would be an appropriate method for evaluating the usability and direct accessibility support provided by the DD. During a second cycle of design research, embedded in the first, we also developed a set of multi-category heuristics as the 'instrument' that could guide the developers during design of applications as well as in the first-level (formative) evaluation thereof. To verify the heuristics, we conducted a usability evaluation of the DD and triangulated the results with a direct field observation at a natural environment of DD use, together with user-administered questionnaires.
A study of evolutionary algorithm selection hyper-heuristics for the one-dimensional bin-packing problemAuthor Nelishia PillaySource: South African Computer Journal 48, pp 31 –40 (2012)More Less
Hyper-heuristics are aimed at providing a generalized solution to optimization problems rather than producing the best result for one or more problem instances. This paper examines the use of evolutionary algorithm (EA) selection hyper-heuristics to solve the offline one-dimensional bin-packing problem. Two EA hyper-heuristics are evaluated. The first (EA-HH1) searches a heuristic space of combinations of low-level construction heuristics for bin selection. The second (EA-HH2) explores a space of combinations of both item selection and bin selection heuristic combinations. These EA hyper-heuristics use tournament selection to choose parents, and mutation and crossover with hill-climbing to create the offspring of each generation. The performance of the hyper-heuristics is compared to that of each of the low-level heuristics applied independently to solve this problem. Furthermore, the performance of both hyper-heuristics is also compared. The comparisons revealed that hyper-heuristics in general perform better than any single low-level construction heuristic in solving the problem. In addition to this it was found that the hyper-heuristic exploring a space of both item selection and bin selection heuristic combinations is more effective than the hyper-heuristic searching a space of just bin selection heuristic combinations. The performance of this hyper-heuristic was found to be comparable to other methods applied to the same benchmark sets of problems.
Understanding the structured processes followed by organisations prior to engaging in agile processes : a South African perspectiveSource: South African Computer Journal 48, pp 41 –58 (2012)More Less
There appears to be a lack of knowledge on the phases South African (SA) organisations go through while adopting agile methods. As a means to address this gap, this study uncovered empirical evidence on the phases SA organisations go through whilst adopting agile methods as well as the disparities between agile prescriptions and the way SA organisations actually implement agile methods.
The data collected using a case study approach was analysed through the lens of Actor-Network Theory (ANT). The results reveal that there is no structured process for adopting agile methods and organisations go through various phases in their attempts to adopt agile methods. During the various phases, organisations face challenges which are culture as well as people related.
Through this study South African practitioners could now be aware that before adopting an agile methodology, there has to be a common understanding of the problems at hand and the envisioned solution. The findings also inform aspiring adopters in South Africa that adoption of the methods does not have to be as prescribed. They are free to adopt only those aspects the organisations need most.