The wide range of applications for single input single output controllers have encouraged interest in monitoring their performance. Over the past two decades researchers in the area have found many performance enhancement opportunities by applying these techniques. These are most evident in large operational plants with hundreds of controllers being monitored at the same time. Early performance measures were based on minimum variance control as a benchmark for controller performance. Many other procedures have since emerged that have improved the level of accuracy in these performance measures. In addition, these improvements made it easier to implement control loop performance monitoring in large industrial settings. This thesis looks at the performance measures in use for single input single output controllers. The work here looks at incorporating these different measures for a specific manufacturing plant. Ways of identifying the goals and objectives of controllers in a system are presented. Furthermore, measures are proposed that most accurately indicate if these goals and objectives are being met. The concept is demonstrated on a distillation system in a gas plant. It is shown how using these objective driven techniques can provide the user with sound results. These results do not require much user analysis to identify sources of problems and areas of improvement.

Behavioural symptoms, cognitive deficits, and findings from electrophysiological, neuroimaging and genetic studies all suggest atypical performance monitoring in ADHD. Performance monitoring involves error detection and post-error behavioural adjustment and is crucial to behavioural self-regulation and reinforcement learning, both of which are dysfunctional in ADHD. Therefore, post-error slowing was examined in children with ADHD and controls using a modified flanker task both with, and without, error detection provided. There was a significant main effect of group on post-error slowing across conditions and when error-detection was provided, significant post-error slowing deficits were found in children with ADHD. These findings suggest that the performance monitoring deficit in ADHD is specific to post-error behavioural adjustment and supports the inclusion of this deficit in the neurocognitive profile of ADHD. Findings are discussed in terms of current neurocognitive reinforcement learning models of ADHD.

Behavioural symptoms, cognitive deficits, and findings from electrophysiological, neuroimaging and genetic studies all suggest atypical performance monitoring in ADHD. Performance monitoring involves error detection and post-error behavioural adjustment and is crucial to behavioural self-regulation and reinforcement learning, both of which are dysfunctional in ADHD. Therefore, post-error slowing was examined in children with ADHD and controls using a modified flanker task both with, and without, error detection provided. There was a significant main effect of group on post-error slowing across conditions and when error-detection was provided, significant post-error slowing deficits were found in children with ADHD. These findings suggest that the performance monitoring deficit in ADHD is specific to post-error behavioural adjustment and supports the inclusion of this deficit in the neurocognitive profile of ADHD. Findings are discussed in terms of current neurocognitive reinforcement learning models of ADHD.

In this dissertation, the effect of mild sleep deprivation on attentional allocation and performance monitoring was investigated using a variety of event-related potential (ERP) paradigms with ecologically realistic periods of sleep deprivation. Seventeen female young adults completed several tasks under alert and sleepy conditions, after 3 and 20 hours of wakefulness, respectively. Objective behavioural measures of response times and error rates indicated virtually no decrements that could be attributed exclusively to sleepiness; however, there were consistent alterations in the ERPs indicative of subtly reduced attentional resources and performance monitoring. The first study (Chapter 2) examined the effect of distraction on the P300, an ERP component related to attention and stimulus processing. Participants performed an auditory oddball task with and without a secondary visual working memory task. Response times (RTs) and P300 amplitudes were affected by the addition of the secondary working memory task. However, an interaction showed that the P300 latency was significantly increased by the secondary task only in the sleepy condition, indicating that processing speed is impaired by a secondary task only when the participant is sleepy. The next study (Chapter 3) used a Go/NoGo contingent negative variation (CNV) task. The CNV is reflective of sustained attention, and is known to be associated with frontal lobe functioning. This task was performed twice, with and without a financial incentive for fast responses, to assess the effect of motivation. The P300 amplitude to the first stimulus and CNV prior to the second were clearly larger to Go stimuli for both levels of alertness when the participant was motivated by the financial incentive. However, with no incentive in the sleepy condition, there was reduced differentiation of the two types of stimuli, indicating a reduced ability to discriminate between important and less important information. In chapters 4 and 5, performance monitoring was examined using two tasks, the Eriksen Flanker task and the Anti-Saccade task, producing an ERP related to errors with two basic components: the error-negativity (Ne/ERN) and error-positivity (Pe), thought to be related to error recognition and error evaluation, respectively. In both data sets, the amplitude of the Ne/ERN was not significantly reduced by sleep deprivation, but the amplitude of the Pe was. In addition, smaller anti-saccade errors produced reduced Ne/ERN amplitudes compared to larger anti-saccade errors. Another marker of performance monitoring is post-error slowing, which was present in the flanker task only during the alert condition. These results indicate that error detection or recognition (Ne/ERN) appears to be relatively preserved during sleep deprivation, but further error evaluation (Pe) and compensation (post-error slowing) are impaired. Taken together, the findings demonstrate that even mild sleep deprivation has a subtle but reliable effect on electrocortical activity associated with attention and performance monitoring despite an absence of behavioural changes, indicating deleterious effects before behavioural changes are observed. Therefore, relying on behavioural tests to determine at what point an individual becomes unsafe to operate machinery or perform various tasks may be misleading.

In this dissertation, the effect of mild sleep deprivation on attentional allocation and performance monitoring was investigated using a variety of event-related potential (ERP) paradigms with ecologically realistic periods of sleep deprivation. Seventeen female young adults completed several tasks under alert and sleepy conditions, after 3 and 20 hours of wakefulness, respectively. Objective behavioural measures of response times and error rates indicated virtually no decrements that could be attributed exclusively to sleepiness; however, there were consistent alterations in the ERPs indicative of subtly reduced attentional resources and performance monitoring. The first study (Chapter 2) examined the effect of distraction on the P300, an ERP component related to attention and stimulus processing. Participants performed an auditory oddball task with and without a secondary visual working memory task. Response times (RTs) and P300 amplitudes were affected by the addition of the secondary working memory task. However, an interaction showed that the P300 latency was significantly increased by the secondary task only in the sleepy condition, indicating that processing speed is impaired by a secondary task only when the participant is sleepy. The next study (Chapter 3) used a Go/NoGo contingent negative variation (CNV) task. The CNV is reflective of sustained attention, and is known to be associated with frontal lobe functioning. This task was performed twice, with and without a financial incentive for fast responses, to assess the effect of motivation. The P300 amplitude to the first stimulus and CNV prior to the second were clearly larger to Go stimuli for both levels of alertness when the participant was motivated by the financial incentive. However, with no incentive in the sleepy condition, there was reduced differentiation of the two types of stimuli, indicating a reduced ability to discriminate between important and less important information. In chapters 4 and 5, performance monitoring was examined using two tasks, the Eriksen Flanker task and the Anti-Saccade task, producing an ERP related to errors with two basic components: the error-negativity (Ne/ERN) and error-positivity (Pe), thought to be related to error recognition and error evaluation, respectively. In both data sets, the amplitude of the Ne/ERN was not significantly reduced by sleep deprivation, but the amplitude of the Pe was. In addition, smaller anti-saccade errors produced reduced Ne/ERN amplitudes compared to larger anti-saccade errors. Another marker of performance monitoring is post-error slowing, which was present in the flanker task only during the alert condition. These results indicate that error detection or recognition (Ne/ERN) appears to be relatively preserved during sleep deprivation, but further error evaluation (Pe) and compensation (post-error slowing) are impaired. Taken together, the findings demonstrate that even mild sleep deprivation has a subtle but reliable effect on electrocortical activity associated with attention and performance monitoring despite an absence of behavioural changes, indicating deleterious effects before behavioural changes are observed. Therefore, relying on behavioural tests to determine at what point an individual becomes unsafe to operate machinery or perform various tasks may be misleading.

Für das zielgerichtete Verhalten des Menschen ist ein funktionierendes Handlungsüberwachungssystem eine wichtige Voraussetzung. Somit können Fehlhandlungen registriert und verarbeitet werden, um dann anschließend das Verhalten an die entsprechende Situation besser anzupassen. Ein wichtiges neuroanatomisches Korrelat dieses Handlungsüberwachungssystems ist der anteriore Anteil des mittleren cingulären Cortex (anterior midcingulate cortex, aMCC), der in der Funktion der Fehlerverarbeitung eng mit den Basalganglien und dem lateralen präfrontalen Cortex verknüpft ist. In der vorliegenden Arbeit wurde die Bedeutung des Thalamus im Netzwerk der Fehlerverarbeitung genauer untersucht. Es konnte mittels diffusionsgewichteter Traktografie bei 16 gesunden Probanden gezeigt werden, dass speziell der Nucleus ventralis anterior (VA) und der Nucleus ventralis lateralis anterior (VLa) quantitativ stärkere Faserverbindungen mit dem aMCC aufweisen, als die restlichen Thalamuskerne. Desweiteren zeigten 15 Patienten mit Läsionen im Thalamus im Vergleich zur gesunden Kontrollgruppe im Eriksen Flanker Task fehlerspezifische Verhaltensunterschiede. Obwohl die Fehlerrate zwischen diesen Patienten und den Kontrollprobanden nahezu identisch war, konnten die Patienten ihre Fehler als solche signifikant schlechter detektieren und ihr Verhalten nach einem Fehler daher auch schlechter anpassen. Die EEG Daten zeigten für die Patientengruppe eine in der Amplitude signifikant verminderte error-related negativity (ERN – ein ereignis-korreliertes Hirnpotential, ausgelöst durch Fehlhandlungen, z.B. in Flankierreizaufgaben) im Vergleich zur Kontrollgruppe. Bei 6 Patienten mit Läsionen der VA und VLa Kerngruppe war die ERN nahezu komplett erloschen, wohingegen bei den 9 Patienten, deren Läsionen nicht VA und VLa betrafen, die ERN lediglich vermindert war. / Performance monitoring is an essential prerequisite of successful goal-directed behavior. Research of the last two decades implicates the anterior midcingulate cortex (aMCC) in the human medial frontal cortex and frontostriatal basal ganglia circuits in this function. Here, we addressed the function of the thalamus in detecting errors and adjusting behavior accordingly. Using diffusion-based tractography we found that, among the thalamic nuclei, the ventral anterior and ventral lateral anterior nuclei (VA, VLa) have the relatively strongest connectivity with the RCZ. Patients with focal thalamic lesions showed diminished error-related negativity, behavioral error detection, and post-error adjustments. When the lesions specifically affected the thalamic VA/VLa nuclei these effects were significantly pronounced, which was reflected by complete absence of the error-related negativity. These results reveal that the thalamus, particularly its VA/VLa region, is a necessary constituent of the performance-monitoring network, anatomically well connected and functionally closely interacting with the aMCC.

Nowadays SoC involves both software and hardware designs, performance bottleneck may occur either in software/hardware or even both. But present performance monitoring tools usually evaluates one of software/hardware performance, which is not quite enough for nowadays SoC designs. Furthermore, due to increasing complexity of user requirements, embedded OS, such as Linux is introduced to manage the limited hardware resources for complicated applications. However, it also makes performance monitoring harder since the memory addressing space is divided into user space and kernel space with different capability to access system resources, which makes user space application impossible to retrieve system performance information without kernel or hardware supports. In this thesis, we propose a performance monitoring tool suite which is capable of analyzing the performance of user pace application, kernel space device driver and AMBA AHB bus for SoC running under Linux. We develop Performance Monitoring Tool Suite (PMTS) which includes: Program Monitor (PM) to monitor the execution time of software; Bus Utilization Monitor (BUM), Bus Contention Monitor (BCM) and Bus Global Monitor (BGM) to monitor the bus utilization, contentions¡Ketc. PMTS can help user to find out the performance bottleneck of both software and hardware more easily. We have applied PMTS to FPGA develop board and find out the hardware/software performance bottlenecks of the designs. From the experimental results we can know that adding PMTS won¡¦t impact the critical path of SoC.

Mine cooling system components are an integral part of a mine‟s ventilation system. A mine‟s reliance on these capital intensive components are set to increase as mines deepen. Mine cooling systems consume up to a quarter of the electricity used on mines. Component efficiency should be monitored to ensure optimum utilisation. Downtime should be minimised so that production is not negatively influenced. Replacing expensive components in an age of severe economic pressure should be avoided altogether. In this study, the performance of mine cooling system components was monitored. The effects of various operational and maintenance interventions on component performance have been quantified. Quantifying the effects of management decisions led to the refining of operational procedures, the optimisation of future maintenance, and the subsequent identification of electrical energy savings potential without the need for expensive modifications. Investigations show that a mine could realise a saving of up to nine hundred thousand rand annually by optimising the maintenance schedule of chillers. Extrapolated results estimate an electrical energy saving of 52 127 MWh per year if the strategy were implemented on twenty of South Africa‟s biggest mines. In addition, a monetary saving in excess of five hundred thousand rand could be saved through refining operational procedures. These strategies will be possible without the need for expensive installations or complicated modifications. Monitoring cooling system performance allows management to identify trends in performance, to understand component inter-dependence, and to allow for informed decision-making. In addition, performance monitoring allows for the identification of component and instrumentation faults. Statistical control charts and simulation modelling are some of the tools that have been employed in this study. These tools assist management formulate strategies and decisions with a higher degree of confidence. / MIng (Mechanical Engineering), North-West University, Potchefstroom Campus, 2014

O Brasil, sendo um país com dimensões continentais, necessita de uma infraestrutura rodoviária que proporcione deslocamentos com conforto e segurança aos seus usuários, bem como transporte eficiente de insumos. Somente através da adequada gerência de pavimentos é possível realizar medidas corretivas nos momentos apropriados, assegurando a manutenção de um nível satisfatório de serventia. Os modelos de previsão de desempenho são ferramentas imprescindíveis na gerência de pavimentos, já que permitem estimar o momento (ou volume de tráfego equivalente) do surgimento de defeitos e programar a realização de serviços de manutenção. A pesquisa relatada nesta dissertação está inserida no projeto Rede Temática do Asfalto, incentivado pela PETROBRAS, e teve por objetivo avaliar o desempenho de dois trechos da rodovia federal BR-290/RS, dando ênfase à análise da influência da variação do lençol freático na deflexão medida no topo deste pavimento. Dando continuidade a estudos anteriores, foram calibradas linhas de tendência propostas para a rodovia em monitoramento, através de levantamentos de deflexões, deformações permanentes, de defeitos superficiais e textura. Ademais, controlou-se a variação da profundidade do lençol freático, através da instalação de um medidor de nível de água no trecho I da BR-290/RS e analisou-se a dependência do módulo de resiliência do solo de subleito em função da umidade de compactação, com ciclos de umedecimento e secagem. Os resultados dos levantamentos demonstraram que os trechos monitorados da BR-290/RS continuam em degradação, com afundamentos nas trilhas de roda e irregularidade longitudinal bastante elevados, sugerindo que intervenções já deveriam ter sido feitas. De forma diferente, a aderência pneu-pavimento e as deflexões apresentam valores aceitáveis. Nos ensaios laboratoriais observou-se que os solos compactados no ramo seco, ou que sofreram ciclos de secagem, apresentaram valores mais elevados de módulo de resiliência do que aqueles compactados no ramo úmido, ou que sofreram ciclos de umedecimento. Os módulos de resiliência mostraram-se quase independentes do estado de tensões e os modelos k-θ apresentaram escassa significância. Por fim, a análise realizada com o software Everstress 5.0 indicou que a oscilação da umidade no subleito influencia nas deflexões do pavimento. Como esperado, quanto maior a umidade, maiores as deflexões. / Brazil, as a country with continental dimensions, needs a road infrastructure that provides comfort and safety to its users, as well as efficient transport of goods. Only through proper pavement management, rehabilitation measures may be taken at appropriate times, ensuring a satisfactory level of serviceability being maintained. Performance models are essential tools in the management of pavements since they allow estimating the time (or equivalent traffic volume) of appearance of distresses and scheduling maintenance services. The research reported in this dissertation is part of the Asphalt Thematic Network project, funded by PETROBRAS, and aimed to evaluate the performance of two sections of federal highway BR-290/RS, with emphasis on the analysis of the influence of the water table variation on deflections measured on the top of this pavement. Continuing previous studies, trend lines were calibrated for pavements under monitoring, through surveys of deflections, permanent deformations, surface distresses and texture. In addition, the variation of the water table depth was controlled by the installation of a water level meter on the section I of BR-290/RS, and the dependence of the resilience module of the subgrade soil was analyzed in function of the compaction water content, with wetting and drying cycles. The results of the surveys showed that the monitored sections of the BR-290/RS continue to deteriorate, with values of rutting and roughness quite high, suggesting that interventions should have already been done. Conversely, the tire-pavement friction and the deflections present acceptable values. In the laboratory tests, it was observed that the soils compacted in the dry branch of the compaction curve, or that underwent drying cycles, presented higher values of resilient modulus than those compacted in the wet branch, or that underwent cycles of wetting. The resilient modules were almost independent of the stress state and the k-θ models presented little significance. Finally, the analysis performed with the software Everstress 5.0 indicated that the oscillation of the humidity in the subgrade influences the deflections of the pavement. As expected, the higher the humidity, the greater the deflections.

O Brasil, sendo um país com dimensões continentais, necessita de uma infraestrutura rodoviária que proporcione deslocamentos com conforto e segurança aos seus usuários, bem como transporte eficiente de insumos. Somente através da adequada gerência de pavimentos é possível realizar medidas corretivas nos momentos apropriados, assegurando a manutenção de um nível satisfatório de serventia. Os modelos de previsão de desempenho são ferramentas imprescindíveis na gerência de pavimentos, já que permitem estimar o momento (ou volume de tráfego equivalente) do surgimento de defeitos e programar a realização de serviços de manutenção. A pesquisa relatada nesta dissertação está inserida no projeto Rede Temática do Asfalto, incentivado pela PETROBRAS, e teve por objetivo avaliar o desempenho de dois trechos da rodovia federal BR-290/RS, dando ênfase à análise da influência da variação do lençol freático na deflexão medida no topo deste pavimento. Dando continuidade a estudos anteriores, foram calibradas linhas de tendência propostas para a rodovia em monitoramento, através de levantamentos de deflexões, deformações permanentes, de defeitos superficiais e textura. Ademais, controlou-se a variação da profundidade do lençol freático, através da instalação de um medidor de nível de água no trecho I da BR-290/RS e analisou-se a dependência do módulo de resiliência do solo de subleito em função da umidade de compactação, com ciclos de umedecimento e secagem. Os resultados dos levantamentos demonstraram que os trechos monitorados da BR-290/RS continuam em degradação, com afundamentos nas trilhas de roda e irregularidade longitudinal bastante elevados, sugerindo que intervenções já deveriam ter sido feitas. De forma diferente, a aderência pneu-pavimento e as deflexões apresentam valores aceitáveis. Nos ensaios laboratoriais observou-se que os solos compactados no ramo seco, ou que sofreram ciclos de secagem, apresentaram valores mais elevados de módulo de resiliência do que aqueles compactados no ramo úmido, ou que sofreram ciclos de umedecimento. Os módulos de resiliência mostraram-se quase independentes do estado de tensões e os modelos k-θ apresentaram escassa significância. Por fim, a análise realizada com o software Everstress 5.0 indicou que a oscilação da umidade no subleito influencia nas deflexões do pavimento. Como esperado, quanto maior a umidade, maiores as deflexões. / Brazil, as a country with continental dimensions, needs a road infrastructure that provides comfort and safety to its users, as well as efficient transport of goods. Only through proper pavement management, rehabilitation measures may be taken at appropriate times, ensuring a satisfactory level of serviceability being maintained. Performance models are essential tools in the management of pavements since they allow estimating the time (or equivalent traffic volume) of appearance of distresses and scheduling maintenance services. The research reported in this dissertation is part of the Asphalt Thematic Network project, funded by PETROBRAS, and aimed to evaluate the performance of two sections of federal highway BR-290/RS, with emphasis on the analysis of the influence of the water table variation on deflections measured on the top of this pavement. Continuing previous studies, trend lines were calibrated for pavements under monitoring, through surveys of deflections, permanent deformations, surface distresses and texture. In addition, the variation of the water table depth was controlled by the installation of a water level meter on the section I of BR-290/RS, and the dependence of the resilience module of the subgrade soil was analyzed in function of the compaction water content, with wetting and drying cycles. The results of the surveys showed that the monitored sections of the BR-290/RS continue to deteriorate, with values of rutting and roughness quite high, suggesting that interventions should have already been done. Conversely, the tire-pavement friction and the deflections present acceptable values. In the laboratory tests, it was observed that the soils compacted in the dry branch of the compaction curve, or that underwent drying cycles, presented higher values of resilient modulus than those compacted in the wet branch, or that underwent cycles of wetting. The resilient modules were almost independent of the stress state and the k-θ models presented little significance. Finally, the analysis performed with the software Everstress 5.0 indicated that the oscillation of the humidity in the subgrade influences the deflections of the pavement. As expected, the higher the humidity, the greater the deflections.