The complexity of the software behind autonomous systems is rapidly growing, as are the applications of what they can do. It is not unusual for the lines of code to reach the millions, which adds to the verification challenge. The machine learning algorithms involved are often "black boxes" where the precise workings are not known by the developer applying them, and their behavior is undefined when encountering an untrained scenario. With so much code, the possibility of bugs or malicious code is considerable. An approach is developed to monitor and possibly override the behavior of autonomous systems independent of the software controlling them. Application-isolated safety monitors are implemented in configurable hardware to ensure that the behavior of an autonomous system is limited to what is intended. The sensor inputs may be shared with the software, but the output from the monitors is only engaged when the system violates its prescribed behavior. For each specific rule the system is expected to follow, a monitor is present processing the relevant sensor information. The behavior is defined in linear temporal logic (LTL) and the associated monitors are implemented in a field programmable gate array (FPGA). An off-the-shelf drone is used to demonstrate the effectiveness of the monitors without any physical modifications to the drone. Upon detection of a violation, appropriate corrective actions are persistently enforced on the autonomous system. / Master of Science / Autonomous systems are surprisingly vulnerable, not just from malicious hackers, but from design errors and oversights. The lines of code required can quickly climb into the millions, and the artificial decision algorithms can be inscrutable and fully dependent upon the information they are trained on. These factors cause the verification of the core software running our autonomous cars, drones, and everything else to be prohibitively difficult by traditional means. Independent safety monitors are implemented to provide internal oversight for these autonomous systems. A semi-automatic design process efficiently creates error-free monitors from safety rules drones need to follow. These monitors remain separate and isolated from the software typically controlling the system, but use the same sensor information. They are embedded in the circuitry and act as their own small, task-specific processors watching to make sure a particular rule is not violated; otherwise, they take control of the system and force corrective behavior. The monitors are added to a consumer off-the-shelf (COTS) drone to demonstrate their effectiveness. For every rule monitored, an override is triggered when they are violated. Their effectiveness depends on reliable sensor information as with any electronic component, and the completeness of the rules detailing these monitors.

This study investigates the possible use of GNSS synchronized PTP grandmasters as a general method for synchronizing IP audio equipment. Two relatively low cost GNSS synchronized PTP grandmaster clocks were built and tested in various real world scenarios. Low latency audio streams were sent over internet between GNSS synchronized audio devices via the protocol SRT, Secure Reliable Transport, and the result was compared to using the commercially available service Jamkazam. It was found that the solution with distributed GNSS synchronized IP audio devices worked well over both LAN and WAN, but the specific SRT solution tested was not suited for really low latency usage like NMP, Networked Music Performance. Further studies are needed to find alternate SRT solutions or other protocols for use when very low latency performance is needed. It was also found that the lowest latency possible was not the most desirable latency when used for monitoring mixes in an NMP context. A latency of 15-20 ms was generally the most preferred, indicating monitor mixes for IEM, In Ear Monitoring, might benefit from introducing delays in the signal chain. More studies are needed to investigate this further.

Battery packs consists of several smaller cells that can drift apart from each other and cause imbalance to the system. These imbalances can be balanced by either dissipating some energy (passive method) or redistributing the excess energy between the cells (active method). In this project they energy efficiency and balancing speed of two active method is investigated and compared to a traditional passive balancing method for 9 cells connected in series. The two active method investigated is the delta structured switched capacitor (DSSC) and chain structure switched inductor (CSSI) method. These methods have the ability to balance any cell with any other cell at any time, which, given the same initial imbalanced cells, results in a much faster balancing speed compared to the passive method.   The energy efficiency and balancing speed was investigated further by examining the energy gained when continuously charging and discharging the cells to model real drive cycles of the cells. This resulted in energy saving corresponding up to 5 Wh more energy per cycle after simulating for about 1900 cycles. This energy gain started however after 1000 cycles due to small imbalance between the cells. The energy gain of the active methods are however not sufficient enough to compensate for their higher component cost when considering the whole life of the cell. However, looking only the second part of the cell’s life, cycled more than 1000 cycles, the energy gain became more clear and the DSSC method start to be more beneficial to use.

Master of Agribusiness / Department of Agricultural Economics / Gregory Ibendahl / One of the latest buzzes amongst agriculture is the storage and analysis of “Big Data.” There are a number of questions surrounding the quality, quantity, and capacity of big data to form real-world decisions based upon past information. Much like the teachings of history, the storybook that big data can reveal about a grower’s operation may hold the answers to the question of: “what is necessary to increase food production which will be required to feed an ever-growing world?” With the increase in interest in precision agriculture, sustainability practices, and the processing of the immense spatial dataset generated on the farm, the next challenge at hand will be in determining how to make technology not only streamlined, but also profitable. Over the past few years, precision agriculture technology has become widely adopted as an agronomic decision making tool. Much like a scientific experiment, the greater the number of similar observations, the greater the degree of confidence can be placed upon a decision. As a means of increasing the number of observations that a farmer can use to base a decision upon, there is becoming increasing demand in being able to combine the data of similar farming operations in order to increase the size and scope of the dataset to generate better decisions benefitting many farms instead of just one. The growing interest in forming community data pools for farm data demonstrates the need for a study for determining how farming practices can be properly benchmarked. The goal was be to evaluate how to use farm data to make economic decisions in a similar manner as one would make agronomic decisions using similar observations. The objective was to design the proper protocol for benchmarking the farm’s potential, and evaluating potential increases in technical efficiency by adopting precision agriculture technology. To accomplish this, a data envelopment analysis was conducted using scale efficiency as a means of determining the frontier of efficient farms. The resounding goal for this study in the future will be to use the model as a means of implementing the secondary process of pooling precision agriculture data to analyze efficiencies gained by the adoption of technology. By demonstrating the value of generating peer groups to increase observations and refine farming practices, farmers can find increased profitability and efficiency by using resources that may already be held within the operation.

Cosmic-ray fluctuations are monitored by neutron monitors using several different kinds of proportional counter tubes. An important component of these monitors is the electronic subsystem that registers and counts output pulses from these counter tubes. Part of the electronic subsystem is a specific preamplifier. The pulse-height distribution curve of the existing preamplifier used in the neutron monitor system at the Centre for Space Research at the North-West University was found to be incorrect, and therefore the pulse-height information cannot be used for further research on the counter tube characteristics. A correct pulse-height distribution implies that the envelope of the pulse, as generated by an amplifier, has a very specific shape as a result of the physics that governs the generation of pulses in the neutron counter tube. It was therefore proposed that a new charge-sensitive preamplifier be synthesized to provide an output that provides the correct pulse-height distribution graph for a neutron monitor system. The Centre for Space Research at the North-West University is in the process of designing and building a new mini neutron monitor system. The new charge-sensitive preamplifier will be implemented into this updated system. Ultimately, the electronic subsystem must be able to provide a pulse-height distribution graph at the push of a button, thus making the preamplifier a key component in the new design. In this dissertation the theory of charge-sensitive amplifiers is researched following a design science research methodology. The results showed that a charge-sensitive amplifier can be synthesized to address both the real-world requirements and the theoretical requirements of this research. / MIng (Electrical and Electronic Engineering), North-West University, Potchefstroom Campus, 2014

Cosmic-ray fluctuations are monitored by neutron monitors using several different kinds of proportional counter tubes. An important component of these monitors is the electronic subsystem that registers and counts output pulses from these counter tubes. Part of the electronic subsystem is a specific preamplifier. The pulse-height distribution curve of the existing preamplifier used in the neutron monitor system at the Centre for Space Research at the North-West University was found to be incorrect, and therefore the pulse-height information cannot be used for further research on the counter tube characteristics. A correct pulse-height distribution implies that the envelope of the pulse, as generated by an amplifier, has a very specific shape as a result of the physics that governs the generation of pulses in the neutron counter tube. It was therefore proposed that a new charge-sensitive preamplifier be synthesized to provide an output that provides the correct pulse-height distribution graph for a neutron monitor system. The Centre for Space Research at the North-West University is in the process of designing and building a new mini neutron monitor system. The new charge-sensitive preamplifier will be implemented into this updated system. Ultimately, the electronic subsystem must be able to provide a pulse-height distribution graph at the push of a button, thus making the preamplifier a key component in the new design. In this dissertation the theory of charge-sensitive amplifiers is researched following a design science research methodology. The results showed that a charge-sensitive amplifier can be synthesized to address both the real-world requirements and the theoretical requirements of this research. / MIng (Electrical and Electronic Engineering), North-West University, Potchefstroom Campus, 2014

e-Learning is becoming an influential role as an economic method and a flexible mode of study in the institutions of higher education today which has a presence in an increasing number of college and university courses. e-Learning as system of systems is a dynamic and scalable environment. Within this environment, e-learning is still searching for a permanent, comfortable and serviceable position that is to be controlled, managed, flexible, accessible and continually up-to-date with the wider university structure. As most academic and business institutions and training centres around the world have adopted the e-learning concept and technology in order to create, deliver and manage their learning materials through the web, it has become the focus of investigation. However, management, monitoring and collaboration between these institutions and centres are limited. Existing technologies such as grid, web services and agents are promising better results. In this research a new architecture has been developed and adopted to make the e-learning environment more dynamic and scalable by dividing it into regional data grids which are managed and monitored by agents. Multi-agent technology has been applied to integrate each regional data grid with others in order to produce an architecture which is more scalable, reliable, and efficient. The result we refer to as Regionally Distributed Architecture for Dynamic e-Learning Environment (RDADeLE). Our RDADeLE architecture is an agent-based grid environment which is composed of components such as learners, staff, nodes, regional grids, grid services and Learning Objects (LOs). These components are built and organised as a multi-agent system (MAS) using the Java Agent Development (JADE) platform. The main role of the agents in our architecture is to control and monitor grid components in order to build an adaptable, extensible, and flexible grid-based e-learning system. Two techniques have been developed and adopted in the architecture to build LOs' information and grid services. The first technique is the XML-based Registries Technique (XRT). In this technique LOs' information is built using XML registries to be discovered by the learners. The registries are written in Dublin Core Metadata Initiative (DCMI) format. The second technique is the Registered-based Services Technique (RST). In this technique the services are grid services which are built using agents. The services are registered with the Directory Facilitator (DF) of a JADE platform in order to be discovered by all other components. All components of the RDADeLE system, including grid service, are built as a multi-agent system (MAS). Each regional grid in the first technique has only its own registry, whereas in the second technique the grid services of all regional grids have to be registered with the DF. We have evaluated the RDADeLE system guided by both techniques by building a simulation of the prototype. The prototype has a main interface which consists of the name of the system (RDADeLE) and a specification table which includes Number of Regional Grids, Number of Nodes, Maximum Number of Learners connected to each node, and Number of Grid Services to be filled by the administrator of the RDADeLE system in order to create the prototype. Using the RST technique shows that the RDADeLE system can be built with more regional grids with less memory consumption. Moreover, using the RST technique shows that more grid services can be registered in the RDADeLE system with a lower average search time and the search performance is increased compared with the XRT technique. Finally, using one or both techniques, the XRT or the RST, in the prototype does not affect the reliability of the RDADeLE system.

Second language acquisition is a field that has fascinated linguists for numerous years and is a topic that is very much connected to how English teachers in Sweden try to teach the English language to the students in their classrooms. In 2009 Sundqvist examined what possible effects extramural English could have on learners' oral proficiency and their vocabulary. In her study she found out that extramural English “is an independent variable and a possible path to progress in English” (Sundqvist, 2009, p. i).  In 2014, three Swedish secondary- and upper secondary school teachers started a project for the Erasmus+. These three teachers tried to create better teaching conditions and to come up with new methods for teaching English. During their investigation they noticed that students who had only been in Sweden for four years or less, seemed to get less exposed to English in their spare time than native Swedish students, which created a disadvantage for them. Since the time when these two studies were carried out, the number of immigrants has increased drastically, which creates the need for further investigation within this area of second language acquisition. In this study, I therefore investigate how much and in what way students come in contact with the English language outside of school. I also examine if there are any differences between native Swedish students versus non-native Swedish students and if so, how this might affect the students and their grades in English. The study was conducted through the use of questionnaires and through observations of different teaching situations, including the participating teachers' methods and the participating students' reactions. The results show that there are differences between native- and non-native students when it comes to extramural English activities. The results also show that these differences seem to affect the students' grades in English, in favour of the native Swedish students. The native students tend to spend more time on extramural English activities, especially in connection to the Internet and computer games, than the non-native students. These results indicate that something needs to be done in order to compensate for the non-native students' disadvantage.

International Telemetering Conference Proceedings / October 25-28, 1999 / Riviera Hotel and Convention Center, Las Vegas, Nevada / In 1998, AlliedSignal Technical Services (ATSC) installed three fully autonomous 13-meter satellite tracking systems for the Integrated Program Office of the National Oceanic and Atmospheric Administration (NOAA) at the Command and Data Acquisition Station near Fairbanks, Alaska. These systems track and command NOAA Polar Orbiting Weather Satellites and Defense Meteorological Satellites. Each tracking system operates for extended periods of time with little intervention other than periodic scheduling contacts. Schedule execution initiates equipment configuration, including establishing the RF communications link to the satellite. Station autonomy is achieved through use of a robust scheduler that permits remote users and the System Administrator to request pass activities for any of the supported missions. Spacecraft in the mission set are scheduled for normal operations according to the priority they have been assigned. Once the scheduler resolves conflicts, it builds a human-readable control script that executes all required support activities. Pass adds or deletes generate new schedule scripts and can be performed in seconds. The systems can be configured to support CCSDS and TDM telemetry processing, but the units installed at Fairbanks required only telemetry and command through-put capabilities. Received telemetry data is buffered on disk-storage for immediate, post-pass playback, and also on tape for long-term archiving purposes. The system can autonomously support up to 20 spacecraft with 5 different configuration setups each. L-Band, S-Band and X-Band frequencies are supported.

International Telemetering Conference Proceedings / October 28-31, 1996 / Town and Country Hotel and Convention Center, San Diego, California / This paper presents a new architecture of the end-to-end ground system to reduce overall mission support costs. The present ground system of the Jet Propulsion Laboratory (JPL) is costly to operate, maintain, deploy, reproduce, and document. In the present climate of shrinking NASA budgets, this proposed architecture takes on added importance as it will dramatically reduce all of the above costs. Currently, the ground support functions (i.e., receiver, tracking, ranging, telemetry, command, monitor and control) are distributed among several subsystems that are housed in individual rack-mounted chassis. These subsystems can be integrated into one portable laptop system using established MultiChip Module (MCM) packaging technology. The large scale integration of subsystems into a small portable system will greatly reduce operations, maintenance and reproduction costs. Several of the subsystems can be implemented using Commercial Off-The-Shelf (COTS) products further decreasing non-recurring engineering costs. The inherent portability of the system will open up new ways for using the ground system at the “point-of-use” site as opposed to maintaining several large centralized stations. This eliminates the propagation delay of the data to the Principal Investigator (PI), enabling the capture of data in real-time and performing multiple tasks concurrently from any location in the world. Sample applications are to use the portable ground system in remote areas or mobile vessels for real-time correlation of satellite data with earth-bound instruments; thus, allowing near real-time feedback and control of scientific instruments. This end-to-end portable ground system will undoubtedly create opportunities for better scientific observation and data acquisition.