In this thesis, low-cost free chlorine sensors for monitoring drinking water have been developed. The starting material, pencil lead, was modified using a ammonium carbamate solution. The main emphasis for this technology is the low cost, scalable and environmental friendly process. The resultant materials were highly sensitive to free chlorine. The second discovery was an advanced understanding of the unsteady state mass transfer during the sensing process, using the customly expanded Cottrell equation. This method could qualitatively indicated the absence of free chlorine, for applications where the removal of free chlorine is the goal. This method allowed better interpretation of transient data and simplified setup. The third discovery was the use of pulsed amperometric detection to detect free chlorine at a much higher sensitivity, while reducing the complexity of the setup, further reducing the cost. This method was based on the previous findings plus understanding of the reaction kinetics. The resultant sensors detected free chlorine with a detection of 0.0414 ppm, while the regulations require the free chlorine to be above 0.2 ppm. The response time was less than three seconds. The range of detection was up to around 20 ppm. The cost of materials for one sensor was less than ten dollars. The maintenance was minimal due to the lack of consumables. The operation could be as a meter or as a device in a large instrument. The target use of the sensors include small and distant communities, bottling industries, fruit and vegetable washing industries. The free chlorine sensing techniques can be readily expanded to biology, environment, and big data applications, based on the knowledge gained through the study. / Thesis / Doctor of Philosophy (PhD) / Low-cost sensors were developed to monitor free chlorine in drinking water for end users, especially in small and distant communities. Free chlorine keeps lethal microorganism pathogens from re-growing after disinfection. Re-growth is more likely to happen in these communities due to poor infrastructure and less usage-driven flow. The contributions include: • A low-cost sensing material for free chlorine based on pencil lead • Determination of operating range of the sensor • Study of sensing mechanisms • Efficiency improvement and cost reduction • Research articles, conference presentations, patent applications, and industrial collaboration based on above research The resultant sensor is easy to use, robust in practical conditions and requires low maintenance, suitable for small and distant communities. Future work is the integration with sensing systems and the application of knowledge gained in this thesis for sensing applications in other fields.

Yes / Low cost carriers (budget airlines) have a significant share of the air travel market, but little research has been done to understand the distributional effect of their operation on key tourism indicators such as length of stay and expenditure. Using data on European visitors to the United Kingdom we demonstrate how counterfactual decompositions can inform us of the true impact of mode of travel. Passengers on low cost carriers tend to spend less, particularly at the upper end of the distribution. Budget airline users typically stay longer, though differences in characteristics of observed groups are important to this result. Counterfactual techniques provide additional valuable insights not obtained from conventional econometric models used in the literature. Illustrating an application of the methodology to policy we demonstrate that enabling respondents to extend their stay generates the greatest additional expenditure at the lower end of the distribution. We also show nationality is a significant characteristic, with important impacts across the expenditure distribution.

ITC/USA 2005 Conference Proceedings / The Forty-First Annual International Telemetering Conference and Technical Exhibition / October 24-27, 2005 / Riviera Hotel & Convention Center, Las Vegas, Nevada / The NASA Space-based Telemetry and Range Safety (STARS) program has developed and tested a low cost Ku-Band transmitter alternative for TDRSS applications based on an existing IRIG shaped offset quaternary phase shift keying (SOQPSK) transmitter. This paper presents information related to the implementation of this low cost system, as well as performance measurements of the alternative TDRSS transmitter system compared with an existing QPSK TDRSS transmitter.

The objective of this research is to develop and demonstrate low-complexity, robust, frequency-scalable, wide-band waveform acquisition techniques for testing high speed com- munication systems. High resolution waveform capture is a versatile testing tool that enables flexible test strategies. However, waveform capture at high data rates requires costly hardware because the increased bandwidth of the signal waveform leads to an increase in the sampling rate requirement, cost of front-end components, and sensitivity to phase errors in traditional (source) synchronous Nyquist-rate tester architectures. The hardware cost and complexity of wide-band waveform acquisition systems can, however, be significantly reduced by using (trigger-free) incoherent undersampling to achieve reduced sampling rates and robustness to phase errors in signal paths. Reducing the hardware cost of such a system using incoherent undersampling requires increased signal processing at the back end. This research proposes computationally-efficient, time-domain waveform reconstruction algorithms to improve both performance, and scope of existing incoherent undersampling- based test instrumentation. Supporting hardware architectures are developed to extend the application of incoherent undersampling-based waveform acquisition techniques to linearity testing of high-speed radio-frequency components without any synchronization between the signals involved, and to the acquisition of wide-band signals beyond the track-and-hold bandwidth barrier of the traditional incoherent undersampling architectures, using multi-channel bandwidth interleaving. The bandwidth is extended in a source-incoherent framework by using mixers to down convert high-frequency signal components to base band followed by digitization using undersampling, and back-end signal processing to reconstruct the original wide-band signal from multiple band-pass components.

International Telemetering Conference Proceedings / October 30-November 02, 1995 / Riviera Hotel, Las Vegas, Nevada / Satellite operations have been inherently manpower intensive since they began over thirty years ago. Since manpower intensive equates to costs, this mode of operations cannot survive in light of government budget cuts and commercial profitability. Two factors are now key for both government and commercial satellite control centers: 1) systems must be highly automated to minimize the operations staff, and 2) these automated systems must be deployed and enhanced at a low cost. This paper describes the three principle challenges which arise in migrating from high-cost, manpower intensive satellite operations to low-cost, automated satellite operations and makes recommendations for solving them.

International Telemetering Conference Proceedings / October 30-November 02, 1995 / Riviera Hotel, Las Vegas, Nevada / The wide use of standard packet telemetry protocols based on the Consultative Committee for Space Data Systems (CCSDS) recommendations in future space science missions has created a large demand for low-cost ground CCSDS processing systems. Some of the National Aeronautics and Space Administration (NASA) missions using CCSDS telemetry include Small Explorer, Earth Observing System (EOS), Space Station, and Advanced Composite Explorer. For each mission, ground telemetry systems are typically used in a variety of applications including spacecraft development facilities, mission control centers, science data processing sites, tracking stations, launch support equipment, and compatibility test systems. The future deployment of EOS spacecraft allowing direct broadcast of data to science users will further increase demand for such systems. For the last ten years, the Data Systems Technology Division (DSTD) at NASA Goddard Space Flight Center (GSFC) has been applying state-of-the-art commercial Very Large Scale Integration (VLSI) Application Specific Integrated Circuit (ASIC) technology to further reduce the cost of ground telemetry data systems. As a continuation of this effort, a new desktop CCSDS processing system is being prototyped that offers up to 150 Mbps performance at a replication cost of less than $20K. This system acts as a gateway that captures and processes CCSDS telemetry streams and delivers them to users over standard commercial network interfaces. This paper describes the development of this prototype system based on the Peripheral Component Interconnect (PCI) bus and 0.6 micron complementary metal oxide semiconductor (CMOS) ASIC technology. The system performs frame synchronization, bit transition density decoding, cyclic redundancy code (CRC) error checking, Reed-Solomon decoding, virtual channel sorting/filtering, packet extraction, and quality annotation and accounting at data rates up to and beyond 150 Mbps.

The study is based on the context of project management; the discipline which employs skills and knowledge to achieve project goals through various project activities. The study concentrates on project management applications to deliver low cost houses (LCH) in the Metsimaholo Local Municipality (MLM). The main purpose of project management application is to enable project managers to track the progress of a project that they are working on. Institutions working on a very large project require project management applications to give periodic updates on the progress of the work that is being done on a project. By using a project management application, the process is made somewhat easier, in the sense that a project manager can just refer and check on the progress him/herself. Provision of adequate housing for the homeless and others who are inadequately housed in an attempt to reduce poverty and improve quality of people’s life has been a huge challenge to the South African government, particularly in the MLM over the years. Globally, legislators on the physical infrastructure of Parliament are pushing for the urgent construction of LCH by the government. The abovementioned challenge has resulted in an enormous housing backlog with poverty, unemployment, economic stagnation and negative behaviour. Financial constrains are seen to escalate costs and this makes the task even more enormous. The hypothesis for this study indicated that MLM does not possess sufficient institutional capacity to implement project management for the effective delivery of low cost housing. The hypothesis and research objectives of the study were validated by means of literature review and empirical surveys. Thirty-four (34) semi structured questionnaires were used to interview participants in the provision of LCH in MLM. The study is made up of five chapters. The study specifically focused on the application of project management to deliver LCH in the Metsimaholo Local Municipality (MLM). •This study contends that the application of project management in the public service sector to deliver goods and services has not been scientifically applied in a conscience and systematic manner. •In the MLM the national, provincial and the municipality efforts are challenged to provide houses for the homeless. •The increasing population in the MLM has resulted in an enormous housing backlog with poverty, unemployment, and economic stagnation. •The high demand for housing in the MLM brings about financial constrains and makes the task even more enormous. •It is realised through this study that the application of project management is lacking; whereby important pillars of project based outputs such as time, quality and cost are not necessarily the resultant finished products of the community tend to inherit. It is evident from the above that while the MLM has a mandate to provide service delivery it is limited by protocol to take full responsibility in the provision of low cost houses. The provision of LCH requires strengthened co-operative governance in the Free State Province, since the three spheres have important roles to play. In the face of the huge backlogs in housing and human settlement provision, the country urgently needs to develop the technical knowledge and skills necessary to fast track housing delivery. / M, Development and Management, Public Management and Administration, North-West University, Vaal Triangle Campus, 2012

International Telemetering Conference Proceedings / October 30-November 02, 1995 / Riviera Hotel, Las Vegas, Nevada / To support initiatives for cheaper, faster, better ground telemetry systems, the Data Systems Technology Division (DSTD) at NASA Goddard Space Flight Center is developing a new Very Large Scale Integration (VLSI) Application Specific Integrated Circuit (ASIC) targeted to dramatically lower the cost of telemetry frame synchronization. This single VLSI device, known as the Parallel Integrated Frame Synchronizer (PIFS) chip, integrates most of the functionality contained in high density 9U VME card frame synchronizer subsystems currently in use. In 1987, a first generation 20 Mbps VMEBus frame synchronizer based on 2.0 micron CMOS VLSI technology was developed by Data Systems Technology Division. In 1990, this subsystem architecture was recast using 0.8 micron ECL & GaAs VLSI to achieve 300 Mbps performance. The PIFS chip, based on 0.7 micron CMOS technology, will provide a superset of the current VMEBus subsystem functions at rates up to 500 Mbps at approximately one-tenth current replication costs. Functions performed by this third generation device include true and inverted 64 bit marker correlation with programmable error tolerances, programmable frame length and marker patterns, programmable search-check-lock-flywheel acquisition strategy, slip detection, and CRC error detection. Acquired frames can optionally be annotated with quality trailer and time stamp. A comprehensive set of cumulative accounting registers are provided on-chip for data quality monitoring. Prototypes of the PIFS chip are expected in October 1995. This paper will describe the architecture and implementation of this new low-cost high functionality device.

The thesis proposes the low-cost solution of Differential GPS using Arduino as a Master Control Unit. The thesis provides the methods of GPS position augmentation, which is available for varied applications such as drones or autonomous lawnmowers operated in a private sector. Used methods of GPS positioning accuracy improvements are based on a Satellite-Based Augmentation System (SBAS) and pseudorange residuals.

Rapid migration of people to the urban areas of developing countries resulted in a shortage of housing and the location of people in poor housing and unhealthy environments. Studies have shown that people who live in poor housing are at increased risk of exposure to the determinants of respiratory diseases. Objective: This study investigated the influence of housing conditions on respiratory disease in selected low cost housing settlements in Johannesburg, South Africa. Methodology: Secondary data analysis based on the Health, Environment and Development (HEAD) cross-sectional study were used to explore housing conditions in relation to respiratory health. Results: Black African households comprised (77%) the major population group in the study. The overall mean number of people per household was five with household size ranging from 1 to 22 people permanently living in the household. Most of the households (48%) had an average monthly income of R1001 to R2000. The self reported household prevalence of asthma was highest among households in Riverlea (21%). Households in Riverlea had reported higher levels of asthma 33% relative to households in Bertrams. Hairdressing activities within dwellings increased the risk of asthma (OR: 2.89, 95% CI 1.46-5.73). Tuberculosis was associated with household size (OR 0.9, 95% CI 0.79 – 0.99) and smoking (OR 0.4 CI 0.12 - 0.96) in the univariate analysis. However in the multivariate analysis there was no significant association between tuberculosis with household size (OR 0.92, 95% CI 0.80 - 1.05) or smoking (OR 0.03, 95% CI 0.12 – 1.00). Conclusion: In this study housing quality was an important determinant of respiratory health. More intervention strategies need to be employed to improve the living environment. These include increasing awareness and education to the public and other sectors, source reduction and more guidelines for healthy housing. Finally, more research on housing and health is needed to determine the effect of housing on health.