South African Computer Journal - Volume 56, Issue 1, 2015
Volumes & issues
Volume 56, Issue 1, 2015
Author Philip MachanickSource: South African Computer Journal 56 (2015)More Less
In this issue, we announce a new editorial board. The previous members served for a long time, and it is time for new blood. The editorial board previously did not have a clearly-defined role. We have adapted the following from IEEE journal practice: The Editorial Board (EB) provides guidance to the Editor-in- Chief. It helps to identify new opportunities to attract authors, it promotes awareness of the journal, and nominates Associate Editors. The EB also serves in the role of Appeal Board in problematic review cases. EB members are encouraged to promote the concept of special issues, and to identify potential themes and guest editors. An EB member is appointed for 5 years with the option to be reappointed for an additional 5 year term.
MUUX-E, a framework of criteria for evaluating the usability, user experience and educational features of m-learning environmentsSource: South African Computer Journal 56, pp 1 –21 (2015)More Less
Higher education students use mobile phones, equipped for Internet access. Mobile technologies can offer effective, satisfying and accessible m-learning experiences. A contribution has been made to knowledge on evaluating m-learning environments and to mobile human-computer interaction (MHCI), with the innovative synthesis of the MUUX-E Framework, which fills a gap in the domain of m-learning. MUUX-E is a single comprehensive, multi-faceted instrument for evaluating m-learning environments, emphasising usability and user experience in mobile educational contexts. It was developed by extensive literature studies on each aspect, and has five categories, 31 criteria and numerous sub-criteria. Using a design-based research paradigm, MUUX-E was applied iteratively to evaluate and enhance successive versions of m-LR, a mobile application created for a Software Engineering module. Participants were students and expert evaluators. MUUX-E served well to identify problems and strengths. The students were more positive than the experts regarding the benefits of m-LR, yet insightfully reported more system problems.
Source: South African Computer Journal 56, pp 22 –32 (2015)More Less
Despite the advantages dynamic reconfiguration adds to a system, it only improves system performance if the execution time exceeds the configuration time. As a result, dynamic reconfiguration is only capable of improving the performance of quasi-static applications. In order to improve the performance of dynamic applications, researchers focus on improving the reconfiguration throughput. These approaches are mostly limited by the bus commonly used to connect the configuration controller to the memory, which contributes to the configuration time. A method proposed to ameliorate this overhead is an architecture utilizing localised block RAM (BRAM) connected to the configuration controller to store the configuration bitstream. The aim of this paper is to illustrate the advantages of the proposed architecture, especially for reconfiguring real-time applications. This is done by validating the throughput of the architecture and comparing this to the maximum theoretical throughput of the internal configuration access port (ICAP). It was found that the proposed architecture is capable of reconfiguring an application within a time-frame suitable for real-time reconfiguration. The drawback of this method is that the BRAM is extremely limited and only a discrete set of configurations can be stored. This paper also proposes a method on how this can be mitigated without affecting the throughput.
Source: South African Computer Journal 56, pp 33 –49 (2015)More Less
Compared to positivist survey and interpretive case study research, design science research (DSR) is a relatively novel and unfamiliar research paradigm within the computing field in South Africa. In light of recent interest in the DSR paradigm, this study sought to investigate how local computing researchers familiarise themselves with an unfamiliar paradigm and what their perspectives of DSR are. Key theoretical concepts from social representations theory (SRT), such as 'anchoring' and 'objectification', were used to explore how researchers constructed their understanding of DSR. A visual approach was used to administer drawing and association tasks to two focus groups; each focus group comprised around 25 participants ranging from doctoral students to experienced researchers. The focus group discussions invoked interesting complementary and distinctive associations about the process and content of DSR, specifically when anchored in dominant and conventional research practices. The results also illustrated several ways in which DSR is objectified in drawings and metaphorical constructions. This study concludes that SRT is useful for exploring beliefs about novel and relatively unfamiliar research practices. This study also contributes to an enhanced understanding of how computing researchers adapt to changing research practices. The findings are developed into recommendations for introducing changes to research practices. These recommendations can be used to direct efforts to more appropriately accommodate changing research practices within the computing community to broaden knowledge generation.
Author Keshnee PadayacheeSource: South African Computer Journal 56, pp 50 –79 (2015)More Less
The insider threat concern is a complex issue, as the problem domain intersects the social, technical and socio-technical dimensions. Consequently, counteracting the insider threat involves in influencing the insider's perceptions and behaviour in order to ensure compliance. When an individual's actions and beliefs are incongruent, this induces a phenomenon known as cognitive dissonance. In order to reduce this dissonance, individuals are self-motivated either to change their behaviours or beliefs, or to rationalize their behaviour. Neutralisation is a technique used by criminals to rationalize maleficence. In terms of the insider threat, it has been proposed that if the rationalisations for committing an offence are eliminated, then the insider is less likely to commit the offence. This process is known as neutralisation mitigation. The research reported on here proposes inducing cognitive dissonance in order to counter the resultant neutralisations that may ensue with neutralisation mitigation. To test these concepts, a pragmatic implementable solution, the Insider Threat Neutralisation Mitigation model predicated on Cognitive Dissonance (ITNMCD), is proposed. A proof-of-concept was developed and the model concept was evaluated using the design science method.
Source: South African Computer Journal 56, pp 80 –106 (2015)More Less
The aim of this paper is to provide an overview of the investigation into customer e-service adoption. The investigation includes a qualitative survey and observation of participants using e-services. E-services are used to attract customers and persuade them to transact online and the customer's perception of an e-service contributes greatly to e-service adoption or rejection. This paper describes the factors that influence customer perception towards e-services. Relationships between the identified factors were also considered in order to build a conceptual framework. Grounded theory was used for its flexibility, repetitive comparisons of data, and emergence of concepts and theories.
Author Nelishia PillaySource: South African Computer Journal 56, pp 107 –119 (2015)More Less
Determining the most appropriate search method or artificial intelligence technique to solve a problem is not always evident and usually requires implementation of different approaches to ascertain this. In some instances a single approach may not be sufficient and hybridization of methods may be needed to find a solution. This process can be time consuming. The paper proposes the use of hyper-heuristics as a means of identifying which method or combination of approaches is needed to solve a problem. The research presented forms part of a larger initiative aimed at using hyper-heuristics to develop intelligent hybrid systems. As an initial step in this direction, this paper investigates this for classical artificial intelligence uninformed and informed search methods, namely depth first search, breadth first search, best first search, hill-climbing and the A* algorithm. The hyper-heuristic determines the search or combination of searches to use to solve the problem. An evolutionary algorithm hyper-heuristic is implemented for this purpose and its performance is evaluated in solving the 8-Puzzle, Towers of Hanoi and Blocks World problems. The hyper-heuristic employs a generational evolutionary algorithm which iteratively refines an initial population. On each iteration the evolutionary algorithm uses tournament selection to select parents. The mutation and crossover operators are applied to the chosen parents to produce offspring for the next generation. The hyper-heuristic was able to identify a search or combination of searches to produce solutions for the twenty 8-Puzzle, five Towers of Hanoi and five Blocks World problems. Furthermore, admissible solutions were produced for all problem instances. A different search or combination of searches was evolved for each problem instance. This study has highlighted the potential of hyper-heuristics for the automated design of intelligent systems. Given this success, future work will investigate the use of hyper-heuristics for the design of intelligent hybrid systems for high-level reasoning, which will combine genetic algorithms, tabu search, variable neighbourhood search and simulated annealing. The automated design of intelligent systems has long term benefits for the software industry as a means of reducing the man hours needed for system design.
Source: South African Computer Journal 56, pp 120 –135 (2015)More Less
This paper investigates optimisation of Evolutionary Hardware Systems (EHW) by means of digital circuit critical path analysis. A 2x2 digital multiplier and a Finite State Machine (FSM) control circuit were evolved using a target-independent Virtual Reconfigurable Circuit (VRC) architecture. An in-depth analysis of the phenotypes' Critical Paths (CP) was performed. Through analysing the CPs, it was shown that a great amount of insight can be gained into a phenotype's fitness. Particularly, the identification of the CP's dependence is valuable, since dependent CPs reduced the required net number of evolved Logic Elements (LE). Generally, in both the multiplier and state phenotypes, the CPs were evolved in ascending order of the net LEs. This suggests that evolution always favoured CPs with lower net numbers. However, we have seen that in one special case, if two independent CPs are used by a third CP, the resulting third CP has a lower net number than both independent CPs. The CP analysis also led to the development of the FitnessOverall fitness function, which had a distinctive way of not only rewarding correct output elements, but also encouraging more efficient evolution through sustaining evolved CPs, and further developing partially-evolved CPs. Finally, by using the optimized fitness function, we demonstrated the evolution of a FSM control circuit. The results verify that optimised GAs can find solutions quicker, and with fewer attempts.
Author Ralf C. StaudemeyerSource: South African Computer Journal 56, pp 136 –154 (2015)More Less
We claim that modelling network traffic as a time series with a supervised learning approach, using known genuine and malicious behaviour, improves intrusion detection. To substantiate this, we trained long short-term memory (LSTM) recurrent neural networks with the training data provided by the DARPA / KDD Cup '99 challenge.
To identify suitable LSTM-RNN network parameters and structure we experimented with various network topologies. We found networks with four memory blocks containing two cells each offer a good compromise between computational cost and detection performance. We applied forget gates and shortcut connections respectively. A learning rate of 0.1 and up to 1,000 epochs showed good results.
We tested the performance on all features and on extracted minimal feature sets respectively. We evaluated different feature sets for the detection of all attacks within one network and also to train networks specialised on individual attack classes. Our results show that the LSTM classifier provides superior performance in comparison to results previously published results of strong static classifiers. With 93.82% accuracy and 22.13 cost, LSTM outperforms the winning entries of the KDD Cup '99 challenge by far. This is due to the fact that LSTM learns to look back in time and correlate consecutive connection records. For the first time ever, we have demonstrated the usefulness of LSTM networks to intrusion detection.
User-centered applications : use of mobile information technologies to promote sustainable school healthcare servicesSource: South African Computer Journal 56, pp 155 –164 (2015)More Less
The youth, especially school going children, are the future of any society. It is therefore important that children should receive adequate healthcare support at an early age in order to strive to preserve and ensure better education and welfare of the children and continuity in societal success. Despite the strategic initiatives that aim at improving the general health of school going children, such as South Africa's Integrated School Health Policy, there still exist challenges in support programmes meant to alleviate the barriers to effective healthcare towards improved education for the school children. Advances in ICT enable a fundamental redesign of healthcare processes based on the use and integration of electronic communication at all levels. New communication technologies can support a transition from institution centric to user-centric applications. This paper defines key principles and challenges for designers, policy makers, and evaluators of user-centred technologies for healthcare in schools. The paper employs the User Experience Management Model (UXM2) to review the current and emerging trends, and highlights challenges related to the design of a typical m-ICT application that supports delivery of healthcare in schools. The paper reaches conclusions for next steps that will advance the domain.
Source: South African Computer Journal 56, pp 165 –167 (2015)More Less
Protecting computing infrastructure is an expensive but necessary task. Companies that run their own computing infrastructure need to be constantly vigilant against intruders on their networks and groups or individuals that seek to intercept their communications.
Companies turn to firewall and intrusion detection system vendors to help them safeguard their information and infrastructure. These companies are putting their faith in expensive devices that attempt to distinguish between friendly and malicious traffic.
Despite the expense and complexity of these systems, malicious users seem to find ways to avoid detection and news of massive breaches have become an almost daily occurrence. We propose to fundamentally change the way to look at information security. We highlight some of the fundamental flaws in current systems and expose risks that many experts know, but do not adequately take into consideration.