This dissertation extends our understanding of how rivalries are formed, what their antecedents are, and how and why they influence consumer choices. Furthermore, the psychological processes underlying the rivalry effects and the moderating effects of temporal focus are uncovered.

A dissertation submitted to the Faculty of Engineenug, University of the Witwatersrand, in fulfilment. of the requirements for the degree of Master of Science in Engineering, / A multi variable control strategy for a grinding circuit at East Driefontein has been implemented by others and has enabled it to operate under stable conditions. The next development needed was to find conditions under which tne efficiency of the circuit was the greatest. Optimum set points exist for the multi variable controller to keep the circuit at its most efficient state. This project was done to determine these set points, and how it affected the operation of the circuit. The strategy involved the collection of process data, the development of mathematical models and the determination of these optimum set points by simulation, This option reduced interference with routine production operations, which is often a prohibiting factor during any development work on an existing process. The optimum set points were successfully determined, and were compared with previous findings and current plant practice. / AC2017

Yes / Although the eurozone sovereign debt crisis took many by surprise following the Global Financial Crisis induced Great Recession, this chapter argues that this was an accident waiting to happen with unjustified emphasis placed upon unproven rules and institutions derived from contemporary neoliberal macroeconomic thinking. First, recent developments in macroeconomic are discussed and evaluated in terms of the so-called New Consensus Macroeconomics (NCM) that forms the current mainstream macroeconomic model comprising a blend of New Classical and New Keynesian theories is through adopting the rational behaviour hypothesis and supply-side-determined long-term equilibrium of output. A particular feature of these ideas is the inclusion of rules and institutions that are perceived to result in time consistent policymaking through essentially binding politicians from undertaking in non-optimal behaviour for either opportunistic, partisan or non-rational expectations reasons. Second, in addition to the general backdrop of macroeconomics the chapter considers the notion of a monetary union between countries under the rubric of both exogenous and endogenous Optimum Currency Area (OCA) theory. This combination of theoretical propositions form the bedrock of the eurozone where the TEU convergence criteria and SGP form the rules, while the European Central Bank is the key institution tasked with delivering low and stable price inflation. However, although these notions have become the staple diet of a generation of mainstream economists they comprehensively failed to insulate the eurozone from its sovereign debt crisis. / Full text of this chapter will be released for public view at the end of the publisher embargo on 1 Nov 2019.

The knowledge of thresholding and gradient at different tissue interfaces is of paramount interest in image segmentation and other imaging methods and applications. Most thresholding and gradient selection methods primarily focus on image histograms and therefore, fail to harness the information generated by intensity patterns in an image. We present a new thresholding and gradient optimization method which accounts for spatial arrangement of intensities forming different objects in an image. Specifically, we recognize object class uncertainty, a histogram-based feature, and formulate an energy function based on its correlation with image gradients that characterizes the objects and shapes in a given image. Finally, this energy function is used to determine optimum thresholds and gradients for various tissue interfaces. The underlying theory behind the method is that objects manifest themselves with fuzzy boundaries in an acquired image and that, in a probabilistic sense; intensities with high class uncertainty are associated with high image gradients generally indicating object/tissue interfaces. The new method simultaneously determines optimum values for both thresholds and gradient parameters at different object/tissue interfaces. The method has been applied on several 2D and 3D medical image data sets and it has successfully determined both thresholds and gradients for different tissue interfaces even when some of the thresholds are almost impossible to locate in their histograms. The accuracy and reproducibility of the method has been examined using 3D multi-row detector computed tomography images of two cadaveric ankles each scanned thrice with repositioning the specimen between two scans.

This dissertation applies a commercial flow simulation software package together with common signal processing techniques to the task of accurately detecting leakage in a large commercial gas pipeline. The techniques developed significantly improved the ability to produce accurate, reliable and stable leak detection predictions for the gas transmission pipeline studied and can be applied generally to other pipelines as well. Recommendations for minimum pipeline requirements to implement successful leak detection are also detailed. There are several commercial software packages available that perform some form of leak detection via system modelling. However, due to the commercial aspects of these products, vendors do not publish the detailed methods of leak detection. This thesis identifies the fundamental techniques required to have accurate and reliable leak detection on a gas transmission pipeline, whilst taking into account the lack of measurement data typically encountered on most gas pipelines. The investigation confirmed that a mass balance technique could be successfully used to produce stable leak detection results for compressible flow in gas transmission pipelines. This leak detection [using mass balance] can be achieved without flow measurement along the pipeline, instead, using only pressure and temperature measurements. Although it is recognized that flow measurement data will greatly improve the ability to detect leaks, the focus of this work is on pipelines where this flow measurement data at intermediate points along the pipeline is not available. It was also demonstrated the reliability of the leak detection was improved by the application of on-line signal processing techniques at various stages of the data processing. / It was clear early into the investigation that the majority of the errors within the leak detection model were created by random errors from the input field data. These non-systematic errors from the measurement data that included pressure and temperature, produced interference with model output. This interference resembled random “white” noise that was removed by a combination of well established data filtering techniques. The most appropriate process of calculating leak detection flow was determined after analysing the results of different techniques applied to large quantities of actual pipeline operating data. The validation of the on-line techniques developed provides a valuable resource for those wishing to implement similar leak detection schemes elsewhere. Furthermore a software environment was chosen which incorporated an open input and output platform for data that could be interfaced with any operating system. Therefore these techniques can be applied to the numerous Supervisory Control and Data Acquisition (SCADA) systems in operation throughout the gas transmission industry, to provide a low cost solution to leak monitoring.

Melbourne, the capital of Victoria Australia leads the world in having the highest quality drinking water. The Victorian State Government has set targets for reducing per capita water consumption by 15%, 25% and 30% by 2010, 2015 and 2020 respectively and has announced stringent water restrictions to curtail water demand. In this resource constraint environment it is opportune to look for alternative sources of water to supplement Melbourne's traditional water supply. In Melbourne, legislation has been changed to make it possible to use rainwater harvested from domestic tanks for non potable purposes. The annual rainfall in Melbourne's metropolitan area varies from 450mm in the West to 850mm in the East to over 1000mm in the North East mountain ranges. The objectives of the current study are to develop a methodology to estimate the optimal size of the rainwater tank at a particular location considering the local rainfall, roof area, demand for water and the reliability of supply (supply security) required; to quantify the rainwater volume that could be harvested at site using domestic rainwater tanks to minimise pressure on the potable water supply secured from traditional catchment sources until the desalination plant is commissioned in 2013; to analyse the efficacy of rainwater tanks to reduce the stormwater runoff and improve the quality of the stormwater that will otherwise flow into urban drains and to estimate the cost effectiveness ratio and payback period of inst alling rainwater tanks. A simple water balance model was developed to calculate the tank size based on daily rainfall, roof area and the expected demand. The concept of 'reliability' was introduced to measure supply security. Rainfall data from 20 rainfall stations scattered around Melbourne were used to determine the variation in the rainwater tank size dependent on the above stated parameters. It was observed that to achieve the same supply reliability (90%) and to meet a specific demand (toilet and garden use), the tank size required in the western side of Melbourne is as high as 7 times as that required in the north-east side. As a result, the

With increased demand for bandwidth-hungry applications such as video-on-demand, wavelength-division-multiplexing passive optical network (WDM-PON) has become a strong contender in overcoming the last mile bottle neck. However, the wide-scale deployment of WDM-PONs has been delayed mainly due to the high cost of wavelength-specific optical components. To realize cost-effective WDM-PONs, various wavelength-independent, so called colorless architectures, have been developed so that all the subscribers can have identical optical network units (ONUs). In such WDM-PONs, however, single-fiber bidirectional transmission results in degradation of system performance caused by interference between the signals and backreflections. This thesis investigates the impact of backreflections on single-fiber bidirectional WDM-PONs. A WDM-PON with various optical line terminals (OLTs) and colorless ONU configurations is presented. The dependence of the power penalty, caused by backreflections, on a variety of parameters is investigated. This includes parameters such as the source linewidths, receiver bandwidth, transmission line loss (TLL), ONU gain, chirp effect at the ONU and optical return loss (ORL), in various WDM-PON configurations. The WDM-PON with continuous wave (CW) seed light and remodulation schemes are both presented and studied experimentally. The impacts of the backreflections on the single-fiber bidirectional WDM-PON with various OLT and ONU configurations are compared and analyzed accordingly.

No description available.

This thesis investigates the cause and implications of the divergent inflationrates of the EMU-12 countries between the years 1998 and 2010. The EMUand the euro are put into a context with the classic theory of Optimum CurrencyArea, where the economic benefits and cost of joining a monetary unionis reviewed. The inflation divergence in the euro area is then described and investigated.Empirically, a Phillips Curve model is constructed in order to determineif the EMU-12 nations’ inflation rates are equally sensitive to changesin unemployment as the EMU average. This is done using a Panel Least Squareestimation for the EMU-12. Each nation is then tested separately against theEMU average. The result provides evidence that the EMU-12 nations’ inflationrates are not equally sensitive to changes in unemployment as the EMU average.The result is negative for the EMU-12 in an Optimum Currency Area context.Given the results, the EMU-12 cannot be considered to be an OptimumCurrency Area, at least not yet.

The aim of this paper is discussion on particular aspects of the extension of a classic example in the design of experiments under the presence of correlated errors. Such extension allows us to study the effect of the correlation range on the design. We discuss the dependence of the information gained by the D-optimum design on the covariance bandwidth and also we concentrate to some technical aspects that occurs in such settings. (author's abstract) / Series: Research Report Series / Department of Statistics and Mathematics