Scielo RSS <![CDATA[South African Computer Journal]]> http://www.scielo.org.za/rss.php?pid=2313-783520190002&lang=en vol. 31 num. 2 lang. en <![CDATA[SciELO Logo]]> http://www.scielo.org.za/img/en/fbpelogp.gif http://www.scielo.org.za <![CDATA[<b>Editorial: Promoting African scholarship</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S2313-78352019000200001&lng=en&nrm=iso&tlng=en <![CDATA[<b>Guest editorial: SAICSIT 2018 special issue</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S2313-78352019000200002&lng=en&nrm=iso&tlng=en <![CDATA[<b>Context-aware technology public discourses and (un)-informed use: The case of users in a developing country</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S2313-78352019000200003&lng=en&nrm=iso&tlng=en There is a move towards a future in which consumers of technology are untethered from the devices and technology use becomes subliminal. With this increasing device opacity, loss of user control and increasing device autonomy, there are calls for more research on users' privacy and freedom of choice. There are, however, key figures in the creation of modern technologies who suggest that consumers are informed of the implications of the use of these technologies or, that consumers use the technologies willingly. This paper examines, using Critical Discourse Analysis, two genres of IT-related communication viz. a speech made by the CEO of Facebook, the largest social-networking site and, the privacy policy document of Truecaller, said to be the most-downloaded app in Africa. Furthermore, 25 Sub-Saharan African users were interviewed on their use and understanding of smartphones. The analysis reveals concerns of consumers regarding the absence of choice, a lack of knowledge and information privacy erosion are not unfounded. The results show also that with the speech and policy document alike, there was information that was distorted or omitted. The conclusion was that the discourses surrounding context-awareness, through confusion, misrepresentations, false assurances and illegitimacy, contribute to information imbalances and asymmetry but most importantly, an uninformed consumer.CATEGORIES: · Human-centered computing ~ Ubiquitous and mobile computing · Security and privacy ~ Human and societal aspects of security and privacy <![CDATA[<b>A method for measuring verb similarity for two closely related languages with application to Zulu and Xhosa</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S2313-78352019000200004&lng=en&nrm=iso&tlng=en There are limited computational resources for Nguni languages and when improving availability for one of the languages, bootstrapping from a related language's resources may be a cost-saving approach. This requires the ability to quantify similarity between any two closely related languages so as to make informed decisions, of which it is unclear how to measure it. We devised a method for quantifying similarity by adapting four extant similar measures, and present a method of quantifying the ratio of verbs that would need phonological conditioning due to consecutive vowels. The verbs selected are those relevant for weather forecasts for Xhosa and Zulu and newly specified as computational grammar rules. The 52 Xhosa and 49 Zulu rules share 42 rules, supporting informal impressions of their similarity. The morphosyntactic similarity reached 59.5% overall on the adapted Driver-Kroeber metric, with past tense rules only at 99.5%. This similarity score is a result of the variation in terminals mainly for the prefix of the verb.CATEGORIES: · Natural language processing ~ Language resources <![CDATA[<b>A functional ontology for information systems</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S2313-78352019000200005&lng=en&nrm=iso&tlng=en The ontology of information systems - the way in which knowledge claims, and thus theories, are conceptualised and represented - is of particular importance in the information systems field, due to its reliance on relations between entities. This work proposes, demonstrates, and evaluates an alternative ontology for theory description which is arguably more powerful and more expressive than the dominant ontological model.CATEGORIES: · Applied computing ~ Enterprise ontologies, taxonomies and vocabularies · Software and its engineering ~ System modeling languages <![CDATA[<b>Design and evaluation of bulk data transfer extensions for the NFComms framework</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S2313-78352019000200006&lng=en&nrm=iso&tlng=en We present the design and implementation of an indirect messaging extension for the existing NFComms framework that provides communication between a network flow processor and host CPU. This extension addresses the bulk throughput limitations of the framework and is intended to work in conjunction with existing communication mediums. Testing of the framework extensions shows an increase in throughput performance of up to 268 χ that of the current direct message passing framework at the cost of increased single message latency of up to 2χ. This trade-off is considered acceptable as the proposed extensions are intended for bulk data transfer only while the existing message passing functionality of the framework is preserved and can be used in situations where low latency is required for small messages. <![CDATA[<b>Applying theories for using non-monetary incentives for citizens to participate in crowdsensing projects</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S2313-78352019000200007&lng=en&nrm=iso&tlng=en In recent years crowdsensing has become a hot topic amongst researchers. Crowdsensing can incentivise and empower citizens to use their mobile phones to collect and share sensed data from their surrounding environments. The purpose of this paper is to report on the application of the incentive theory and the Theory of Planned Behaviour (TPB) as a lens from which to investigate the non-monetary incentives and participation profiles (intentions and motivations) of citizens from around the world, who could participate in a crowdsensing project for water resource monitoring (WRM). The conceptual framework was used in a survey of citizens. The findings revealed that TPB can be successfully used for predicting behavioural intentions and classified several types of motivational factors for participation in crowdsensing projects for WRM. Guidelines for crowdsensing projects are provided that can improve the success rate of WRM projects.CATEGORIES: · Information systems ~ Collaborative and social computing systems and tools · Human-centred computing ~ Empirical studies in ubiquitous and mobile computing <![CDATA[<b>Mobile enterprise application adoption: A South African insurance study</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S2313-78352019000200008&lng=en&nrm=iso&tlng=en The factors impacting mobile enterprise application (MEA) adoption are important as they contribute to usage and subsequently improved business performance. By means of a literature review, conceptual design of a model, survey and qualitative analysis, this mixed method study examined factors influencing user adoption of MEAs in the insurance industry. The conceptualised model combined elements of the extended technology acceptance model with constructs from Vuolle and Käpylä's mobile work model. The data collected supported the overall validity of the model and all, but one of the hypotheses were supported. Interesting findings include the importance of willingness to fund devices on the adoption by users and the importance of job relevance and the location dependency of the MEAs on their usefulness. These findings are relevant to organizations deploying MEAs and researchers studying adoption.CATEGORIES: · Information systems ~ Mobile information processing systems <![CDATA[<b>Leveraging intrinsic resources for the protection of health information assets</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S2313-78352019000200009&lng=en&nrm=iso&tlng=en The prevailing state of rural economies continues to constrain the use of digital applications for improved healthcare. These constraints are attributed to the unavailability of key infrastructure and financial resources. Moreover, a prevailing shortage of skilled health workers highlights the critical role digital solutions have to play in alleviating health service delivery challenges. Resource-constrained settings need secure low cost and long shelf-life solutions that leverage existing resources to provide adequate and secure health services. The objective of this paper is to identify the existing resources that can be engaged in the protection of the broader health information assets (including digital applications). To meet the objective, a single case study was conducted. Questionnaires were distributed to twenty-five Community Health Workers to identify existing stressors and resources in the context. The paper leads with a description of resource-constrained settings, highlights the challenges facing healthcare systems in these contexts and emphasizes the need for health information asset protection. The findings, recommendations and conclusions are subsequently presented. The contribution of this paper is a set of recommendations for improving health information asset protection in resource-constrained settings as informed by stressors and resources identified in the case study.CATEGORIES: · Security and privacy ~ Social aspects of security and privacy <![CDATA[<b>Improving functional density of time-critical applications using hardware-based dynamic reconfiguration and bitstream specialisation</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S2313-78352019000200010&lng=en&nrm=iso&tlng=en The dynamic reconfiguration of an FPGA has many advantages, but the overhead from the process reduces the functional density of applications. Functional density is an indication of the composite benefits a reconfigured application obtains above its generic counterpart and measures the computational throughput per unit hardware resources. Typically, only quasi-static applications obtain a functional density advantage by dynamically reconfiguring its parameters. Contributing to the functional density reduction of applications with tight time constraints is the overhead to generate a new configuration, and the time it takes to load it onto the device. Normally these applications have to reuse their hardware numerous times between configurations before obtaining a functional density advantage. The most promising reconfiguration method to improve functional density with minimal hardware reuse was one that extracts certain characteristics from the bitstream and then implements a bitstream specialiser that generates new hardware at bit-level while the device is being reconfigured. While it was shown that this method allows reconfiguration of an application in real-time, its effect on functional density was not determined. This paper will show that a significant increase in functional density can be achieved for applications where reconfiguration is required before the next execution cycle of the application.CATEGORIES: · Hardware ~ Reconfigurable logic and FPGAs · Computer systems organization ~ Other architectures <![CDATA[<b>The design and implementation of a robust scheme to combat the effect of malicious nodes in cognitive radio ad hoc networks</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S2313-78352019000200011&lng=en&nrm=iso&tlng=en A cognitive radio network, which enables dynamic spectrum access, addresses the scarcity of radio spectrum caused by ever-increasing demand for spectrum. Cognitive radio technology ensures the efficient utilisation of underutilised licenced spectrum by secondary users (SUs). SUs sense the radio environment before utilising the available spectrum to avoid signal interference. The SUs cooperatively sense the spectrum to ensure a global view of the network. Unfortunately, cooperative sensing is vulnerable to Byzantine attacks whereby SUs falsify the spectrum reports for selfish reasons. Hence, this study proposes the implementation of a scheme to combat the effects of Byzantine attack in cognitive radio networks. The proposed scheme, known as the extreme studentized cooperative consensus spectrum sensing (ESCCSS), was implemented in an ad hoc cognitive radio network environment where the use of a data fusion centre (DFC) is not required. Cognitive radio nodes perform their own data fusion before making spectrum access decisions. They fuse their own reports with reports from neighbouring nodes. To evaluate the performance of our scheme and its effectiveness in combating the effect of Byzantine attack, comparative results are presented. The comparative results show that the ESCCSS outperformed the Attack-Proof Cooperative Spectrum Sensing scheme.CATEGORIES: · Networks ~ Network security · Networks ~ Ad hoc networks <![CDATA[<b>SAICSIT Papers in the ACM-DL</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S2313-78352019000200012&lng=en&nrm=iso&tlng=en A cognitive radio network, which enables dynamic spectrum access, addresses the scarcity of radio spectrum caused by ever-increasing demand for spectrum. Cognitive radio technology ensures the efficient utilisation of underutilised licenced spectrum by secondary users (SUs). SUs sense the radio environment before utilising the available spectrum to avoid signal interference. The SUs cooperatively sense the spectrum to ensure a global view of the network. Unfortunately, cooperative sensing is vulnerable to Byzantine attacks whereby SUs falsify the spectrum reports for selfish reasons. Hence, this study proposes the implementation of a scheme to combat the effects of Byzantine attack in cognitive radio networks. The proposed scheme, known as the extreme studentized cooperative consensus spectrum sensing (ESCCSS), was implemented in an ad hoc cognitive radio network environment where the use of a data fusion centre (DFC) is not required. Cognitive radio nodes perform their own data fusion before making spectrum access decisions. They fuse their own reports with reports from neighbouring nodes. To evaluate the performance of our scheme and its effectiveness in combating the effect of Byzantine attack, comparative results are presented. The comparative results show that the ESCCSS outperformed the Attack-Proof Cooperative Spectrum Sensing scheme.CATEGORIES: · Networks ~ Network security · Networks ~ Ad hoc networks