http://hdl.handle.net/10386/2526 Sun, 12 Apr 2026 13:34:27 GMT 2026-04-12T13:34:27Z http://hdl.handle.net/10386/4255 A data security and privacy scheme for user quality of experience in a Mobile Edge Computing-based network Foko Sindjoung, Miguel Landry; Velempini, Mthulisi; Djamegni, Clémentin Tayou Cloud computing has widely been used for applications that require huge computational and data storage resources. Unfortunately, with the advent of new technologies such as fifth generation of cellular networks that provide new applications like IoT, cloud computing presents many limits among which the End-To-End (E2E) latency is the main challenge. These applications generally degrade scenarios that require low latency. Mobile Edge Computing (MEC) has been proposed to solve this issue. MEC brings computing and storage resources from cloud data center to edge data center, closer to end-user equipment to reduce the E2E latency for request processing. However, MEC is vulnerable to security, data privacy, and authentication that affect the end-user Quality of Experience (QoE). It is therefore fundamental that these challenges are addressed to avoid poor user experience due to the lack of security or data privacy. In this paper, we propose a hybrid cryptographic system that uses the symmetric and asymmetric cryptographic systems, to improve data security, privacy, and user authentication in a MEC-based network. We show that our proposed scheme is secured by validating it with the Automated Validation of Internet Security Protocol and Application tool. Simulation results show that our solution consumes less computing resources. Journal article published in the journal of Array 19 (2023) 100304 Sun, 01 Jan 2023 00:00:00 GMT http://hdl.handle.net/10386/4255 2023-01-01T00:00:00Z http://hdl.handle.net/10386/3087 Unsteady MHD Flow of Non-Newtonian Fluid in a Channel Filled with a Saturated Porous Medium with Asymmetric Navier Slip and Convective Heating Rundora, L; Makinde, O. D This paper aims to computationally study the effects of Navier slip on an unsteady hydromagnetic flow of a pressure driven, reactive, variable viscosity, electrically conducting third-grade fluid through a porous saturated medium with asymmetrical convective boundary conditions. It is assumed that the chemical kinetics in the flow system is exothermic and that the asymmetric convective heat exchange with the surrounding medium at the surfaces follows Newtons law of cooling. The coupled nonlinear partial differential equations governing the flow and heat transfer are derived and solved numerically using a semi-implicit finite difference scheme. The flow and heat transfer characteristics are analyzed graphically and discussed for different values of the parameters embedded in the system. It is observed that the lower wall slip parameter increases the fluid velocity profiles. The upper wall slip parameter is seen to retard the velocity profiles while it increases the fluid temperature profiles. The wall slip parameters increase the skin friction and the Nusselt number. The wall slip parameters as well as the variable viscosity parameter, the viscous heating parameter and the numerical exponent m reduce the thermal criticality values of the reaction parameter. Article published in the Applied Mathematics & Information Sciences Mon, 01 Jan 2018 00:00:00 GMT http://hdl.handle.net/10386/3087 2018-01-01T00:00:00Z http://hdl.handle.net/10386/2966 The Design and Implementation of the XWCETT Routing Algorithm in Cognitive Radio Based Wireless Mesh Networks Velempini, M.; Kola, L. M. The Wireless Mesh Networks (WMNs) technology has recently emerged as a promising high-speed broadband communication. In a multi hop ad hoc cognitive radio network(CRN)environment, the performance of the network is degraded by the routing protocols, which are adapted from the traditional wireless networks. In an endeavor to optimize the performance of the CRNs, existing routing protocols can be adapted and optimized. Secondly, new dynamic routing protocols can be designed to meet the requirements of CRNs. This paper investigates the existing routing protocols in WMNs and proposes a new routing protocol called extended Weighted Cumulative Expected Transmission Time(xWCETT). .The xWCETT routing protocol was evaluated through network simulations using the NS2.Its performance was evaluated with respect to the end-to-end average latency, and the normalized routing load. The comparative evaluation results show that the xWCETT achieves superior results in terms of average throughput, latency, and the normalized routing load. Article published in the Hindawi Wireless Communications and Mobile Computing Volume 2018 Mon, 01 Jan 2018 00:00:00 GMT http://hdl.handle.net/10386/2966 2018-01-01T00:00:00Z http://hdl.handle.net/10386/2528 Probabilistic Hourly Loading Forecasting Using AdditiveProbabilistic Hourly Load Forecasting Using Additive Quantile Regression Models Sigauke, Caston; Maposa, Daniel; Nemukula, Murendeni Maurel Short-term hourly load forecasting in South Africa using additive quantile regression (AQR) models is discussed in this study. The modelling approach allows for easy interpretability and accounting for residual autocorrelation in the joint modelling of hourly electricity data. A comparative analysis is done using generalised additive models (GAMs). In both modelling frameworks, variable selection is done using least absolute shrinkage and selection operator (Lasso) via hierarchical interactions. Four models considered are GAMs and AQR models with and without interactions, respectively. The AQR model with pairwise interactions was found to be the best fitting model. The forecasts from the four models were then combined using an algorithm based on the pinball loss (convex combination model) and also using quantile regression averaging (QRA). The AQR model with interactions was then compared with the convex combination and QRA models and the QRA model gave the most accurate forecasts. Except for the AQR model with interactions, the other two models (convex combination model and QRA model) gave prediction interval coverage probabilities that were valid for the 90% , 95% and the 99% prediction intervals. The QRA model had the smallest prediction interval normalised average width and prediction interval normalised average deviation. The modelling framework discussed in this paper has established that going beyond summary performance statistics in forecasting has merit as it gives more insight into the developed forecasting models. View Full-Text Journal article Mon, 01 Jan 2018 00:00:00 GMT http://hdl.handle.net/10386/2528 2018-01-01T00:00:00Z