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Simulated sensor data from active and passive sensors has numerous applications in target detection and tracking. Simulated data is particularly useful in performance evaluation of target tracking algorithms where the ground truth of a scenario must be known. For real sensor data it is impossible to know the ground truth so simulated data must be used. This paper discusses existing methods for simulation of data from active sensors and proposes a method that builds on existing techniques from the field of computer graphics. An extension to existing methods is proposed to accommodate the simulation of active sensor data for which timing and frequency information is required in addition to intensity. Results from an existing method of active sensor data simulation are compared to the results of the proposed method. Additionally, a cloud computing framework is proposed and its scalability evaluated to address the fairly large computational load of such a simulation. / Thesis / Master of Applied Science (MASc)

No / Increasing number of sophisticated services provided by the current wireless communication systems have caused a significant transition from E-commerce to M-commerce. Enterprises have provided considerable new opportunities to promote their businesses accessible from small mobile devices such as personal digital assistant (PDA) or mobiles phones. These facilities are envisioned as the most convenient way of using M-commerce. Using such services from mobile phones or PDAs equipped with GSM/GPRS involve effective mobility management mechanisms in cellular networks¿a popular architecture for wireless networks. Success of such systems will largely depend on the reliable connection for the roaming users. Consequently, Quality of Service (QoS) provision is one of the most challenging issues in the heterogeneous wireless network-based m-commerce systems. Such m-commerce systems enable users to roam between different wireless networks operators and geographical areas while providing interactive broadband services and seamless connectivity. This paper presents an analytical framework to model scarce channels in any cell for maximizing channel utilization and efficient handling of handover requests. Typical numerical experiments are presented to validate the analytical solution against simulation to study the effect of bursty traffic upon the performance of the cell in any cellular networks.

In this thesis, we benchmark the Cognitive Radios Test System version 2.0 (CRTSv.2) to analyze its software performance with respect to its internal structure and design choices. With the help of system monitoring and profiling tools, CRTSv.2 is tested to quantitatively evaluate its features and understand its shortcomings. With the help of GNU Radio, a popular, easy-to-use software radios framework, we ascertain that CRTSv.2 has a low memory footprint, fewer dependencies and overall, is a lightweight framework that can potentially be used for real-time signal processing. Several open-source measurement tools such as valgrind, perf, top, etc. are used to evaluate the CPU utilization, memory footprint and to postulate the origins of latencies. Based on our evaluation, we observe that CRTSv.2 shows a CPU utilization of approximately 9% whereas GNU Radio is 59%. CRTSv.2 has lower heap memory consumption of approximately 3MB to GNU Radio's 25MB. This study establishes a methodology to evaluate the performance of two SDR frameworks systematically and quantitatively. / Master of Science / When picking the best person for the job, we rely on the person's performance in past projects of a similar nature. The same can be said for software. Software radios provide the capability to perform signal processing functions in software, making them prime candidates towards solving modern problems such as spectrum scarcity, internet-of-things(IoT) adoption, vehicle-to-vehicle communication etc. In order to operate and configure software radios, software frameworks are provided that let the user make changes to the waveform, perform signal processing and data management. In this thesis, we consider two such frameworks,GNU Radio and CRTSv.2. A software performance evaluation is conducted to assess framework overheads contributing to operation of an orthogonal frequency-division multiplexing (OFDM) digital modulation scheme. This provides a quantitative analysis of a signals-specific use case which can be used by researchers to evaluate the optimal framework for research. This analysis can be generalized for different signal processing capabilities by understanding the total framework overhead removed from signal processing costs.

<p>Effective teamwork and communication are critical to patient outcomes, and subjective assessment tools have been developed for measuring team performance using both technical and non-technical skills. However, inherent biases remain with using subjective assessment tools.</p><p>In this study, 3rd-year medical students participated in the Acute Care Trauma Simulation (ACTS). The student performed the role of clinician in a team that included a nurse and a simulated patient. Participants conducted post-operative patient management, patient care diagnoses, and treatment. Audio from all team members was recorded, and speech variables (e.g., speech duration, frequency of interaction, etc.) from student’s audio were extracted.</p><p>The models for Research Question I showed that increasing frequency of checkbacks between student and nurse (p<0.05) and speech duration from student to patient (p=0.001) significantly increased student’s clinical performance score. In Research Question II, a positive association (ρ=0.456, p<0.001) between speech duration from student to patient and overall NTS scores was observed, and this correlation was the strongest amongst all other vocal features with overall NTS score.</p><p>Both studies showed significant positive relationships between key vocal features (e.g., speech duration), frequency of communication with respect to performance. Metrics and vocal features derived from audio recordings can be measured in predicting clinical performance and NTS, moreover, it can further contribute to the understanding of communication in the healthcare setting. Most importantly, the potential of providing an objective approach for simulation-based trauma care training.</p><div><br></div>

Thesis (MPAM.(Public Administration)) --University of Limpopo, 2021 / The study investigated the impact of Government-wide Monitoring and Evaluation System on the performance of government. Cloete (2009) postulates that in 2005, the Executive of the State approved the Government-wide M&E System (GWM&ES) as a broad framework to examine monitoring and evaluation of activities in all government departments with a view to guaranteeing effective executive decision-making in support of execution; advisory evidence-based resource apportionment; on-going policy development; as well as review. This study specifically investigated the impact of the Government-wide Monitoring and Evaluation System to enhance performance in the Office of the Premier in Limpopo provincial government. The common thread according to majority of the scholars and review reports on this system as shown in the literature review of this study is that government’s major challenge is that it is has become ineffective and, in the process, fails to attain the objectives it has set itself to achieve. This is largely on account of the absence of a clear-cut and coherent systematic mechanism that could enable the public sector to evaluate its performance and identify the factors which contribute to its service delivery outcomes and overall performance. In the same vein, the those charged with the responsibility to help assess the performance of government are unable to draw causal connections between the choice of policy priorities, the resourcing of those policy objectives, the programmes designed to implement them, the services delivered and their ultimate impact on communities. In this study the qualitative research methodology was adopted which was utilised to gather data. The findings of this research identified certain factors which undermine the impact of GWM&ES on government performance; the limitations to fully comprehend and integrate the system within the planning processes and above all implement the required institutional arrangements and/or mechanisms so that there is a visible impact and enhancement of the planning regime and service delivery capacity of the various institutions of the state. Although work has since begun in this regard, including the establishment of the Ministry of Planning, Monitoring and Evaluation in The Presidency, an inadequate institutional merger of the M&E and Planning branches in the Office of the Premier in Limpopo in particular, remains an impediment. Following the analysis of the data collected, of which was sufficient to suffice, the study concludes by proposing a set of measures to ensure that the Government-wide Monitoring and Evaluation System has the necessary impact towards enhancing the performance of the Office of the Premier, and by extension, the entire government because the system is not only limited to one institution of the state, but also integrative by design. These measures include, amongst others, that the Government-wide Monitoring and Evaluation System, as a system of systems, should be fully comprehended, adopted and implemented in government. This will inevitably produce the requisite results in terms of strengthening and improving evidence-based planning, policy development and budgeting, and thereby improve the performance of government, and in particular, the Office of the Premier in Limpopo. A replica study in other areas is further recommended to enhance the implementation of the system

Context. Introduction of efficient multimedia technologies combined with the spreading of high-speed internet connection all over the world has led to the continuous increase in demand of multimedia services, particularly video and audio. One of the major demands are flexible, interoperable and cost-effective lightweight remote collaboration systems in companies. Web Real Time Communication (WebRTC) is an emerging peer to peer technology that is promising to be the solution to many digital real-time communication challenges. With its fantastic one-to-one communication capabilities, WebRTC supports fast and smooth audio calls, video calls, conferencing, data (media file, document and screen) sharing, gaming and all sorts of messages exchange, all being done straight out of the browser. However, as shown by investigations and interviews supported by Ericsson AB and Semcon AB as party of the MERCO (Mediated Effective Remote Collaboration) international project, many corporate use cases of remote collaboration involve applications beyond the conventional one to one communication. Present videoconferencing systems (telepresence) limits the collaboration flexibility due to their lack of the ability to adapt to system resource usage, hence tend to be too heavy for less powerful devices (laptops, tablets, phones). Moreover, their installation and maintenance costs are too expensive for small companies.  Therefore, new flexible, lightweight and less expensive solutions for remote collaboration need to be developed. Objectives. The main objective of this thesis is to identify technical solutions to address the challenges of resource usage flexibility in WebRTC multi-party remote collaboration systems. Despite concurrent developments of both commercial and free solutions that provide multi-party videoconferencing services using WebRTC, present solutions such as the conventional Multipoint Control Unit (MCU), Selective Forwarding Unit (SFU) and Fully Meshed architectures suffers from issues of excessive resource usage and cannot deliver the acceptable quality of experience in different use cases, particularly the mobile environment. The aim of this thesis is to investigate lightweight technical solutions that can be used to improve the system resource usage in WebRTC multiparty conferencing systems. Through understanding the architectural designs, benchmarking the performance of various technologies used in WebRTC and selecting the most suitable techniques a prototype is developed as a proof of concept. Methods. The first part of the thesis is dedicated to comprehensive study of fundamentals, background information and related works on WebRTC. This gives knowledge of technologies, techniques and performance evaluation metrics which help in making appropriate technical decisions during the experimental development of WebRTC solutions. The second part of the thesis is dedicated to experimental investigation in which two WebRTC signaling technologies (XSockets and NodeJs) are evaluated based on call setup time in WebRTC group call. Two lightweight technical solutions for improving resource usage flexibility (Switching video quality based on speech and using emotions and gestures instead of video) are evaluated based on system resources (CPU, memory, disk and network) and user experience. Results. Based on call setup time of WebRTC multi-party calls, the experimental results indicates that XSockets is a better signaling technology than NodeJs. The two proposed lightweight solutions have shown a remarkable improvement based on systems resource usage. A 15% reduction of CPU usage is observed when using speech controlled video quality switching and further 10% reduction is observed when video is replaced by emotions and gestures. Conclusions. Despite the minimal resource usage achieved by using emotions technique, this solution has usability issues as it cannot detect emotions in poor lighting environment. Consequently, the solution of switching video quality based on speech is chosen for further implementation. Though, this technique can be further improved through using machine learning techniques, the current implementation can significantly reduce the amount CPU, memory, disk and network usage to allow up to 6 participants to join a single conference call while maintain acceptable quality of experience.

published_or_final_version / Psychology / Doctoral / Doctor of Philosophy

Mobile Ad-hoc Networks (MANETs) have received considerable research interest in recent years. Because of dynamic topology and limited resources, it is challenging to design routing protocols for MANETs. In this dissertation, we focus on the scalability and efficiency problems in designing routing protocols for MANETs. We design the Way Point Routing (WPR) model for medium to large networks. WPR selects a number of nodes on a route as waypoints and divides the route into segments at the waypoints. Waypoint nodes run a high-level inter-segment routing protocol, and nodes on each segment run a low-level intra-segment routing protocol. We use DSR and AODV as the inter-segment and the intra-segment routing protocols, respectively. We term this instantiation the DSR Over AODV (DOA) routing protocol. We develop Salvaging Route Reply (SRR) to salvage undeliverable route reply (RREP) messages. We propose two SRR schemes: SRR1 and SRR2. In SRR1, a salvor actively broadcasts a one-hop salvage request to find an alternative path to the source. In SRR2, nodes passively learn an alternative path from duplicate route request (RREQ) packets. A salvor uses the alternative path to forward a RREP when the original path is broken. We propose Multiple-Target Route Discovery (MTRD) to aggregate multiple route requests into one RREQ message and to discover multiple targets simultaneously. When a source initiates a route discovery, it first tries to attach its request to existing RREQ packets that it relays. MTRD improves routing performance by reducing the number of regular route discoveries. We develop a new scheme called Bilateral Route Discovery (BRD), in which both source and destination actively participate in a route discovery process. BRD consists of two halves: a source route discovery and a destination route discovery, each searching for the other. BRD has the potential to reduce control overhead by one half. We propose an efficient and generalized approach called Accumulated Path Metric (APM) to support High-Throughput Metrics (HTMs). APM finds the shortest path without collecting topology information and without running a shortest-path algorithm. Moreover, we develop the Broadcast Ordering (BO) technique to suppress unnecessary RREQ transmissions.

As a throughput-oriented device, Graphics Processing Unit(GPU) has already integrated with cache, which is similar to CPU cores. However, the applications in GPGPU computing exhibit distinct memory access patterns. Normally, the cache, in GPU cores, suffers from threads contention and resources over-utilization, whereas few detailed works excavate the root of this phenomenon. In this work, we adequately analyze the memory accesses from twenty benchmarks based on reuse distance theory and quantify their patterns. Additionally, we discuss the optimization suggestions, and implement a Bypassing Aware(BA) Cache which could intellectually bypass the thrashing-prone candidates. BA cache is a cost efficient cache design with two extra bits in each line, they are flags to make the bypassing decision and find the victim cache line. Experimental results show that BA cache can improve the system performance around 20\% and reduce the cache miss rate around 11\% compared with traditional design.