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Scheduling of aperiodic and independent tasks in hard real-time symmetric multiprocessing systems is an NP-complete problem that is often solved using heuristics like particle swarm optimization (PSO). The performance of these class of heuristics, known as evolutionary algorithms, are often evaluated based on the number of iterations it takes to find a solution. Such metrics provide limited information on how the algorithm reaches a solution and how the process could be accelerated. This thesis presents a methodology to analyze the trajectory formed by candidate solutions in order to analyze them in both the time and frequency domains at a single scale. The analysis entails (i) the impact of different parameters for the PSO algorithm, and (ii) the evolutionary processes in the swarm. The work reveals that particles have a directed movement towards a solution during a transient phase, and then enter a steady state where they perform an unguided local search. The scheduling algorithm presented in this thesis uses a variation of the minimum total tardiness with cumulative penalties cost function, that can be extended to suit different system needs. The experimental results show that the scheduler is able to distribute tasks to meet the real-time deadlines over 1, 2, and 4 processors and up to 30 tasks with overall system loads of up to 50\% in fewer than 1,000 iterations. When scheduling greater loads, the scheduler reaches local solutions with 1 to 2 missed deadlines, while larger tasks sets take longer to converge. The trajectories of the particles during the scheduling algorithm are examined as a means to emphasize the impact of the behaviour on the application performance and give insight into ways to improve the algorithm for both space and terrestrial applications.

Engineering educators the world over are being faced with the dilemma of combining traditional mathematically intensive courses, like Control Systems and Robotics with advances in computational hardware and software. This is because it is impractical to include both software engineering issues as well as conventional course content. A solution to the problem lies in Rapid Prototyping technology to develop and design software, for application on PC's and embedded systems. Rapid Prototyping, based on automatic code generation, allows users to develop advanced software on high level graphical platforms like Simulink® and LabView®, while " hiding" the underlying layers of complex code. This approach allows the advanced hardware, traditionally reserved for software engineers, to be accessed by a much wider audience and is an ideal educational tool. This thesis presents the complete development of the Rapid Application Development Environment (RADE). The RADE system customises the Mathworks Real Time Workshop (RTW) revision 11 for application on both standalone and networked DS? cards. The functionality of the RTW is incorporated into the RADE system. This affords the user seamless code generation, downloading, on-line parameter tuning and on-line data visualisation with storage capability. An added advantage of the RADE system is its easy portability to multiple target platforms, which is demonstrated by its implementation on two different DSP cards. Finally the functionality of the RADE system is demonstrated as an educational tool, with the demonstration of a DC motor speed and position controller. / Thesis (M.Sc.Eng.-University of Natal, Durban, 2001.

This dissertation focuses on the application of tomography in the sugar milling process, specifically within the vacuum pan. The research aims to improve the efficiency and throughput of a sugar mill by producing real-time images of the boiling dynamic in the pan and hence can be used as a diagnostic tool. The real-time tomography system is a combination of ruggedized data collecting hardware, a switching circuit and software algorithms. The system described in this dissertation uses 16 electrodes and estimates images based on the distinct differences in conductivities to be found in the vacuum pan, i.e. a conductive syrup-like fluid (massecuite) and bubbles. There is a direct correlation between the bubbles produced during the boiling process and heat transfer in the pan. From this correlation one can determine how well the pan is operating. The system has been developed in order to monitor specific parts of a pan for optimal boiling. A binary reconstructed image identifies either massecuite or water vapour. Each image is reconstructed using a modified neighbourhood data collection method and a back projection algorithm. The data collection and image reconstruction take place simultaneously, making it possible to generate images in real-time. Each image frame is reconstructed at approximately 1.1 frames per second. Most of the system was developed in LabVIEW, with some added external drive electronics, and functions seamlessly. The tomography system is LAN enabled hence measurements are initiated through a remote PC on the same network and the reconstructed images are streamed to the user. The laboratory results demonstrate that it is possible to generate tomographic images from bubbles vs massecuite, tap water and deionized water in real-time. / Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, Durban, 2012.

Group A rotaviruses are a major cause of acute gastroenteritis in children. Almost all children are infected by the age of 5 years old. Rotavirus disease causes around 600,000 deaths per year. VP4 (P) and VP7 (G) genotypes were analyzed for prevalence and potential antigenicity, as they are known to elicit a neutralizing antibody response during infection. This study predicted the effectiveness of two recently licensed rotavirus vaccines based on Canadian surveillance. 271 out of 348 diarrhea samples from 8 paediatric hospital were successfully genotyped by PCR. Canadian rotavirus genotypes were found to be mostly G1P[8] followed by G3P[8], G2P[4], G9P[8], G4P[8], and G9P[4], between 2007 and 2010. Reassortment and motif analysis was done with a subset of rotavirus-positive samples. There were no unusual reassortment events found in Canadian strains. Variations amongst strains were commonly genotype-specific, but otherwise rare. In conclusion, rotavirus vaccine escape is presently unlikely amongst Canadian strains.

The model- and component-based development approach has emerged as an attractive option for the development of Distributed Real-time Embedded (DRE) systems. In this thesis we target several issues such as modeling of legacy communication, extraction of end-to-end timing models and support for holistic response-time analysis of industrial component-based DRE systems. We introduce a new approach for modeling legacy network communication in component-based DRE systems. By introducing special-purpose components to encapsulate and abstract the communication protocols in DRE systems, we allow the use of legacy nodes and legacy protocols in a component- and model-based software engineering environment. The proposed approach also supports the state-of-the-practice development of component-based DRE systems. The Controller Area Network (CAN) is one of the widely used real-time networks in DRE systems especially in automotive domain. We identify that the existing analysis of CAN does not support common message transmission patterns which are implemented by some high-level protocols used in the industry. Consequently, we extend the existing analysis to facilitate the worst-case response-time computation of these transmission patterns. The extended analysis is generally applicable to any high-level protocol for CAN that uses periodic, sporadic, or both periodic and sporadic transmission of messages. Because an end-to-end timing model should be available to perform the holistic response-time analysis, we present a method to extract the end-to-end timing models from component-based DRE systems. In order to show the applicability of our modeling techniques and extended analysis, we provide a proof of concept by extending the existing industrial component model (Rubus Component Model), implementing the holistic response-time analysis along with the extended analysis of CAN in the industrial tool suite (Rubus-ICE), and conducting an automotive case study. / EEMDEF

FlexRay is a deterministic communication bus in the automotive context that supports fault-tolerant and high-speed bus system. It operates based on the time-division-multiple-access scheme and allows transmission of event-driven and time-driven messages between nodes in a system. A FlexRay bus has two periodic segments which form a bus cycle: static segment and dynamic segment. Such a bus system could be used in a wide area of real-time automotive applications with soft and hard timing constraints. Recent research has been focused on the FlexRay static segment. As opposed to the static segment, however, the dynamic one is based on an event-triggered scheme. This scheme is more difficult to be temporally predicted. Nevertheless, the event-triggered paradigm provides more flexibility for further incremental design. The dynamic segment is also suitable for applications with erratic data size. Such advantages motivate for more research on the dynamic segment. In a real-time system, results of the computations have to be ready by a specific instant of time called deadline . However, in a soft real-time application, the result can be used with a degraded Quality of Service even after the deadline has passed while in a hard real-time system, missing a deadline leads to a catastrophe. This thesis aims at optimizing some of the parameters of the FlexRay bus for soft real-time applications. The cost function which helps to assess the solution to the optimization problem is the deadline miss ratio and a solution to our problem consists of two parts: (1) Frame identifiers to messages which are produced at each node. (2) The size of each individual minislot which is one of the FlexRay bus parameters. The optimization is done based on genetic algorithms. To evaluate the proposed approach, several experiments have been conducted based on the FlexRay bus simulator implemented in this thesis. The achieved results show that suitable choice of the parameters which are generated by our optimization engine improves the timing behavior of simulated communicating nodes.

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