Дисертації з теми "Water hammer Data processing"

All land uses affect storm water runoff However, different uses of the same site generate varying amounts of runoff Many communities have come to rely upon detention and/or retention basins for controlling the additional runoff resulting from land development. It is argued that this incremental approach to storm water management must be replaced with a more proactive long-term view.To achieve this, more user-friendly software capable of modeling the effect long-range land use plans have on the volume and behavior of storm water runoff is needed. This software, called a Spatial Decision Support System (SDSS), must be capable of guiding the user, who may not be an expert at runoff analysis, through the process and also capable of generating output in various formats understandable by lay persons. This study utilizes a systems analysis technique to develop a theoretical framework for the Storm Water SDSS.
Department of Urban Planning

[eng] The main objective proposed in this doctoral thesis was focused on the study and development of a solution for the remote sensing of the submarine topographic relief, using for this, inexpensive equipment. Here we focus in three works that altogether will improve the remote sensing process for underwater medium using sonars as the main relief data acquisition system. The problem was systematically addressed since the previous work in the master thesis, constituting three stages: 1) building a prototype data extraction platform, 2) data acquisition and 3) data processing. In the first stage was developed a prototype taking as a reference the modular structure and the software design applied in AUVI project (Acosta 2008), and besides it was used the model of autonomous navigation system developed to AutoTracker project (Acosta et al., 2005), this stage and part of the following one were developed in the master thesis. In the second stage, it was done the survey planning and the acoustic data extraction including navigational data in three different places: i) On the cove “Estancia”, located in Palma, Mallorca island/Spain, where we used the prototype developed in the first stage of this work as a platform to data extraction; ii) “Alfeite Arsenal” Port, located on the Tejo River, in Almada/Portugal into the context of robotics exercises promoted by the Navy of Portugal (REX2014). In this location, it was used the robotic vehicle ZARCO from the Oceansys Lab, through cooperative work with the Oceansys Lab. research group at the University of Porto (UP)/INESC in Portugal and finally, iii) in the “Bay of All Saints”, near the city of Salvador/Brazil, where were performed some missions to collect data using hydrographic survey boats in cooperation with the Federal University of Bahia (UFBA) and Belov Engineering - Port Engineering and Hydrographic Services Company, both located in Salvador/Bahia. Finally, the third stage, that is the main body of this thesis, was characterized by the data analysis and comparison between several datasets. In this stage, studies had been conducted to verify the feasibility of the use of spatial statistical algorithms in the process of bathymetric data interpolation without any ancillary information to support the prediction. We determined an optimized procedure for estimating the unsampled points, hence it was validated using a regular cross-validation method and a comparative validation method to compare the estimated data with a second dataset acquired in the same region and acting as a Merit Figure. The average discrepancy between the estimated data and Merit Figure data value was 25 cm, it is below the acceptable error for bathymetric data at depths below 30m (IHO 2012). In addition, an algorithm based on the Stochastic Resonance (SR) theory was developed. It consists in applying white noise in an optimal intensity level to improve the contrasts of acoustic images generated by a side Sonar Scan (SSS). The SR theory also, was used as a basis for development of a weak signals detection algorithm in sensing applications. Regarding the sensors application for measure remote sensing physical variables, we could cite the magnetic field meters (magnetometers), and inertial sensors (accelerometers and gyroscopes), in this study was performed a simulation of Chua's circuit operating in a chaotic regime as a sensor, where we could determine successfully the region of system solution into the strange attractor, using, for this, the technique of residence time, which will be defined along this thesis. The entire set of modules, techniques and processes described in this work proposed one solution to the remote sensing problem applied to the underwater environment, and give the opportunity to develop in more deep way future works in sensor integration, algorithms and data acquisition platform.
[cat] L'objectiu principal proposat en aquesta tesi doctoral es va centrar en l'estudi i desenvolupament d'una solució per a la detecció remota del relleu topogràfic submarí, utilitzant per a això un equip econòmic. Aquí ens centrem en tres treballs que en total milloraran el procés de teledetecció per al medi submarí utilitzant sonars com el principal sistema d'adquisició de dades de relleu. El problema es va abordar sistemàticament des del treball anterior a la tesi de màster, que constava de tres etapes: 1) construcció d'una plataforma d'extracció de dades prototip, 2) adquisició de dades i 3) tractament de dades. En la primera etapa es va desenvolupar un prototip prenent com a referència l'estructura modular i el disseny de programari aplicat en el projecte AUVI (Acosta 2008), a més d'utilitzar el model de sistema de navegació autònom desenvolupat per al projecte AutoTracker (Acosta et al., 2005 ), aquesta etapa i una part de la següent es van desenvolupar en la tesi de màster. En la segona etapa, es va realitzar la planificació de l'enquesta i l'extracció de dades acústiques, incloses les dades de navegació en tres llocs diferents: i) A la cala "Estancia", situada a Palma, illa de Mallorca / Espanya, on utilitzem el prototip desenvolupat a la primera etapa d'aquest treball com a plataforma d'extracció de dades; ii) Port "Alfeite Arsenal", ubicat al riu Tajo, a Almada / Portugal, en el context dels exercicis de robòtica promoguts per l'Armada de Portugal (REX2014). En aquesta ubicació, es va utilitzar el vehicle robotitzat ZARCO del laboratori Oceansys, a través del treball cooperatiu amb l'Oceansys Lab. grup d'investigació de la Universitat de Porto (UP) / INESC a Portugal i, finalment, iii) a la "Badia de Tots Sants", a prop de la ciutat de Salvador / Brasil, on es van realitzar algunes missions per recollir dades utilitzant vaixells d'enquestes hidrogràfiques en cooperació amb la Universitat Federal de Bahia (UFBA) i Belov Engineering - Port Engineering and Hydrographic Services Company, ambdós ubicats a Salvador / Bahia. Finalment, la tercera etapa, que és el cos principal d'aquesta tesi, es va caracteritzar per l'anàlisi de dades i la comparació entre diversos conjunts de dades. En aquesta etapa, s'han realitzat estudis per verificar la viabilitat de l'ús d'algoritmes estadístics espacials en el procés d'interpolació de dades batimètriques sense cap tipus d'informació auxiliar per a la predicció. Es va determinar un procediment optimitzat per estimar els punts sense mostrejar, per tant, es va validar mitjançant un mètode de validació de mètodes regular i un mètode de validació comparatiu per comparar les dades estimades amb un segon conjunt de dades adquirit a la mateixa regió i actuant com a Figura de mèrit. La discrepància mitjana entre les dades estimades i el valor de dades de Merit Figure va ser de 25 cm, per sota de l'error acceptable per a dades batimètriques a profunditats inferiors a 30 m (IHO 2012). A més, es va desenvolupar un algorisme basat en la teoria de la ressonància estocàstica (SR). Consisteix en aplicar soroll blanc en un nivell d'intensitat òptima per millorar els contrastos d'imatges acústiques generades per un costat Sonar Scan (SSS). La teoria del SR també es va utilitzar com a base per al desenvolupament d'un algoritme de detecció de senyals feble en la detecció d'aplicacions. Pel que fa a l'aplicació de sensors per a la mesura de les variables físiques de control remot, podríem citar els mesuradors de camp magnètic (magnetòmetres) i els sensors inercials (acceleròmetres i giroscopis), en aquest estudi es va realitzar una simulació del circuit de Chua que funciona en un règim caòtic com a sensor, on podríem determinar amb èxit la regió de la solució del sistema en l'estrany atractor, utilitzant, per a això, la tècnica del temps de residència, que es definirà al llarg d'aquesta tesi. Tot el conjunt de mòduls, tècniques i processos descrits en aquest treball proposen una solució al problema de teledetecció aplicat a l'entorn submarí i permeten desenvolupar de manera més profunda futurs treballs en integració de sensors, algorismes i plataforma d'adquisició de dades..
[spa] El principal objetivo propuesto en esta tesis doctoral se centró en el estudio y desarrollo de una solución para la detección remota del relieve topográfico submarino, utilizando para esto, equipos de bajo costo. Aquí nos enfocamos en tres trabajos que en conjunto mejorarán el proceso de detección remota para medios subacuáticos usando sonares como el principal sistema de adquisición de datos de alivio. El problema fue abordado sistemáticamente desde el trabajo anterior en la tesis de maestría, constituyendo tres etapas: 1) construcción de una plataforma prototipo de extracción de datos, 2) adquisición de datos y 3) procesamiento de datos. En la primera etapa se desarrolló un prototipo tomando como referencia la estructura modular y el diseño de software aplicado en el proyecto AUVI (Acosta 2008), y además se utilizó el modelo de sistema de navegación autónomo desarrollado para el proyecto AutoTracker (Acosta et al., 2005 ), esta etapa y parte de la siguiente se desarrollaron en la tesis de maestría. En la segunda etapa, se realizó la planificación de la encuesta y la extracción de datos acústicos, incluyendo datos de navegación en tres lugares diferentes: i) En la cala "Estancia", ubicada en Palma, isla de Mallorca / España, donde utilizamos el prototipo desarrollado en el primera etapa de este trabajo como una plataforma para la extracción de datos; ii) Puerto "Alfeite Arsenal", ubicado en el río Tajo, en Almada / Portugal en el contexto de ejercicios de robótica promovidos por la Armada de Portugal (REX2014). En esta ubicación, se utilizó el vehículo robótico ZARCO del Laboratorio Oceansys, a través del trabajo cooperativo con el Laboratorio Oceansys. grupo de investigación en la Universidad de Oporto (UP) / INESC en Portugal y finalmente, iii) en la "Bahía de Todos los Santos", cerca de la ciudad de Salvador / Brasil, donde se realizaron algunas misiones para recopilar datos utilizando barcos hidrográficos en cooperación con la Universidad Federal de Bahía (UFBA) y Belov Engineering - Compañía de Ingeniería Portuaria y Servicios Hidrográficos, ambas ubicadas en Salvador / Bahía. Finalmente, la tercera etapa, que es el cuerpo principal de esta tesis, se caracterizó por el análisis de datos y la comparación entre varios conjuntos de datos. En esta etapa, se realizaron estudios para verificar la viabilidad del uso de algoritmos estadísticos espaciales en el proceso de interpolación de datos batimétricos sin ninguna información auxiliar para respaldar la predicción. Determinamos un procedimiento optimizado para estimar los puntos no muestreados, por lo que se validó utilizando un método de validación cruzada regular y un método de validación comparativa para comparar los datos estimados con un segundo conjunto de datos adquiridos en la misma región y actuando como una figura de mérito. La discrepancia promedio entre los datos estimados y el valor de los datos de Merit Figure fue de 25 cm, está por debajo del error aceptable para los datos batimétricos a profundidades por debajo de 30 m (OHI 2012). Además, se desarrolló un algoritmo basado en la teoría de la Resonancia Estocástica (SR). Consiste en aplicar ruido blanco en un nivel de intensidad óptimo para mejorar los contrastes de las imágenes acústicas generadas por un Sonar Scan lateral (SSS). La teoría SR también se usó como base para el desarrollo de un algoritmo de detección de señales débiles en aplicaciones de detección. En cuanto a la aplicación de sensores para medir variables físicas de teledetección, podríamos citar los medidores de campo magnético (magnetómetros) y sensores inerciales (acelerómetros y giroscopios), en este estudio se realizó una simulación del circuito de Chua operando en un régimen caótico como sensor, donde pudimos determinar con éxito la región de la solución del sistema en el atractor extraño, utilizando, para ello, la técnica del tiempo de residencia, que se definirá a lo largo de esta tesis. El conjunto completo de módulos, técnicas y procesos descritos en este trabajo propuso una solución al problema de teledetección aplicado al entorno subacuático, y brinda la oportunidad de desarrollar de manera más profunda futuros trabajos de integración de sensores, algoritmos y plataforma de adquisición de datos.
[por] O objetivo principal proposto nesta tese de doutorado foi focado no estudo e desenvolvimento de uma solução para o sensoriamento remoto do alívio topográfico submarino, usando para isso, equipamentos baratos. Aqui nos concentramos em três trabalhos que, em conjunto, melhorarão o processo de sensoriamento remoto para o meio subaquático, utilizando os sonares como o principal sistema de aquisição de dados de alívio. O problema foi sistematicamente abordado desde o trabalho anterior na tese de mestrado, constituindo três etapas: 1) construção de um protótipo de plataforma de extração de dados, 2) aquisição de dados e 3) processamento de dados. Na primeira etapa foi desenvolvido um protótipo tomando como referência a estrutura modular e o projeto de software aplicado no projeto AUVI (Acosta 2008), e além disso, utilizou-se o modelo de sistema de navegação autônomo desenvolvido para o projeto AutoTracker (Acosta et al., 2005 ), este estágio e parte do seguinte foram desenvolvidos na tese de mestrado. Na segunda etapa, foi feito o planejamento da pesquisa e a extração de dados acústicos, incluindo dados de navegação em três lugares diferentes: i) Na enseada "Estancia", localizada em Palma, Ilha de Maiorca / Espanha, onde usamos o protótipo desenvolvido no primeira etapa deste trabalho como plataforma para a extração de dados; ii) Porto do "Alfeite Arsenal", localizado no rio Tejo, em Almada / Portugal no contexto de exercícios de robótica promovidos pela Marinha de Portugal (REX2014). Nessa localização, utilizou-se o veículo robotizado ZARCO do Laboratório Oceansys, através do trabalho cooperativo com o Oceansys Lab. grupo de pesquisa na Universidade do Porto (UP) / INESC em Portugal e, finalmente, iii) na "Baía de Todos os Santos", perto da cidade de Salvador / Brasil, onde foram realizadas algumas missões para coletar dados usando embarcações hidrográficas em cooperação com a Universidade Federal da Bahia (UFBA) e a Engenharia Belov - Empresa de Engenharia de Portos e Hidrográficos, ambos localizados em Salvador / Bahia. Finalmente, o terceiro estágio, que é o corpo principal desta tese, foi caracterizado pela análise de dados e comparação entre vários conjuntos de dados. Nesta fase, foram realizados estudos para verificar a viabilidade do uso de algoritmos estatísticos espaciais no processo de interpolação de dados batimétricos sem qualquer informação auxiliar para sustentar a predição. Determinamos um procedimento otimizado para estimar os pontos não amostrados, portanto, foi validado usando um método de validação cruzada regular e um método de validação comparativa para comparar os dados estimados com um segundo conjunto de dados adquirido na mesma região e atuando como uma Figura de mérito. A discrepância média entre os dados estimados eo valor de dados da Figura de Mérito foi de 25 cm, está abaixo do erro aceitável para dados batimétricos a profundidades abaixo de 30 m (IHO 2012). Além disso, um algoritmo baseado na teoria da Ressonância Estocástica (SR) foi desenvolvido. Consiste na aplicação de ruído branco em um nível de intensidade ótimo para melhorar os contrastes de imagens acústicas geradas por um lado de Sonar Scan (SSS). A teoria SR também foi utilizada como base para o desenvolvimento de um algoritmo de detecção de sinais fracos em aplicações de detecção. Em relação ao aplicativo de sensores para medir as variáveis físicas de sensoriamento remoto, podemos citar os medidores de campo magnético (magnetômetros) e sensores inerciais (acelerômetros e giroscópios), neste estudo realizou-se uma simulação do circuito de Chua operando em regime caótico como sensor, onde podemos determinar com sucesso a região da solução do sistema no atrativo estranho, usando, para isso, a técnica de tempo de residência, que será definida ao longo desta tese. Todo o conjunto de módulos, técnicas e processos descritos neste trabalho propôs uma solução para o problema de sensoriamento remoto aplicado ao ambiente subaquático e oferece a oportunidade de desenvolver de forma mais profunda os futuros trabalhos em integração de sensores, algoritmos e plataforma de aquisição de dados.

"August 2001." Includes bibliographical references (leaves 77-80). Examines the susceptibility of existing signal processing methods to errors and identifies other possible causes of depth error not accounted for by existing signal processing methods, by analysis of the detected laser return waveform data. Methods to improve depth accuracy are investigated.

D. Tech. (Department of Civil Engineering and Building, Faculty of Engineering and Technology), Vaal University of Technology
Growing demand for water due to increasing populations, industrialisation and water consuming lifestyles puts stress on existing water supply systems. To cater for the rising demand, water distribution networks are expanded beyond their design capacities and this creates transient “low-pressure-open-channel flow” (LPOCF) conditions. Current water supply models use “demand driven approach” (DDA) methodology which is not able to simulate transient LPOCF conditions, that poses an impediment to management/analysis of pressure-deficient networks. With a case study of the water supply network of Kampala City, LPOCF conditions were studied in this research. A “pressure/head driven approach” (PDA/HDA) was used in order to determine what demand is enabled by particular nodal pressures. Conversion of free surface to pressurised flow was analysed and modelled, with a view to clearly understanding occurrence of this phenomenon. The research demonstrated that if adequate pressures and flows are to be maintained, effectiveness of the water distribution network should be given as much attention as water production capacity. The research also indicated that when network pressures are low, the head-driven approach to water distribution modelling gives more accurate results than the traditional demand-driven methodology. Coexistence of free-surface and pressurised flow in networks prone to LPOCF conditions was confirmed and modelled. Results obtained highlighted the advantages of developing fully dynamic and transient models in the solution of transient LPOCF conditions in water distribution networks. Models developed allow application of PDA/HDA and DDA methodologies in systems that may exhibit LPOCF conditions thus enabling identification, understanding and analysis of the status of all sections of the network. These culminated in the development of a DSS to guide operational decisions that can be made to optimise network performance.

The research has entailed the formulation and coding of computer models for the design of pressurized irrigation systems. Particular emphasis has been given to the provision of routines for the evaluation of the expected performance from a designed system. Two separate sets of models have been developed, one for the block or in-field system and one for file mainline netWork. The thesis is presented in three seelions asfollows : * Basic theory, in which the general background to the research is covered. * The models, which includes detailed descriptions of both the design models and the computer programs. * Applications, in which several test casesof both sets of models are reported.

This project is focused on the goal of improving access to the Water Resources Institute (WRI) archives using a web-based GIS architecture. This project uses the newest version of ArcGIS Server as a method to support an internet-based map search environment, improved information management and data sharing.

Thesis submitted in fulfilment of the requirements for the degree Doctor of Technology: Electrical Engineering in the Faculty of Engineering at the Cape Peninsula University of Technology 2014
This thesis focuses on the design, development and real-time simulation of a robust nonlinear networked control for the dissolved oxygen concentration as part of the wastewater distributed systems. This concept differs from previous methods of wastewater control in the sense that the controller and the wastewater treatment plants are separated by a wide geographical distance and exchange data through a communication medium. The communication network introduced between the controller and the DO process creates imperfections during its operation, as time delays which are an object of investigation in the thesis. Due to the communication network imperfections, new control strategies that take cognisance of the network imperfections in the process of the controller design are needed to provide adequate robustness for the DO process control system. This thesis first investigates the effects of constant and random network induced time delays and the effects of controller parameters on the DO process behaviour with a view to using the obtained information to design an appropriate controller for the networked closed loop system. On the basis of the above information, a Smith predictor delay compensation controller is developed in the thesis to eliminate the deadtime, provide robustness and improve the performance of the DO process. Two approaches are adopted in the design of the Smith predictor compensation scheme. The first is the transfer function approach that allows a linearized model of the DO process to be described in the frequency domain. The second one is the nonlinear linearising approach in the time domain. Simulation results reveal that the developed Smith predictor controllers out-performed the nonlinear linearising controller designed for the DO process without time delays by compensating for the network imperfections and maintaining the DO concentration within a desired acceptable level. The transfer function approach of designing the Smith predictor is found to perform better under small time delays but the performance deteriorates under large time delays and disturbances. It is also found to respond faster than the nonlinear approach. The nonlinear feedback linearisig approach is slower in response time but out-performs the transfer function approach in providing robustness and performance for the DO process under large time delays and disturbances. The developed Smith predictor compensation schemes were later simulated in a real-time platform using LabVIEW. The Smith predictor controllers developed in this thesis can be applied to other process control plants apart from the wastewater plants, where distributed control is required. It can also be applied in the nuclear reactor plants where remote control is required in hazardous conditions. The developed LabVIEW real-time simulation environment would be a valuable tool for researchers and students in the field of control system engineering. Lastly, this thesis would form the basis for further research in the field of distributed wastewater control.

[EN] Over time, due to multiple operational and maintenance activities, the networks of water supply systems (WSSs) undergo interventions, modifications or even are closed. In many cases, these activities are not properly registered. Knowledge of the paths and characteristics (status and age, etc.) of the WSS pipes is obviously necessary for efficient and dynamic management of such systems. This problem is greatly augmented by considering the detection and control of leaks. Access to reliable leakage information is a complex task. In many cases, leaks are detected when the damage is already considerable, which brings high social and economic costs. In this sense, non-destructive methods (e.g., ground penetrating radar - GPR) may be a constructive response to these problems, since they allow, as evidenced in this thesis, to ascertain paths of pipes, identify component characteristics, and detect primordial water leaks. Selection of GPR in this work is justified by its characteristics as non-destructive technique that allows studying both metallic and non-metallic objects. Although the capture of information with GPR is usually successful, such aspects as the capture settings, the large volume of generated information, and the use and interpretation of such information require high level of skill and experience. This dissertation may be seen as a step forward towards the development of tools able to tackle the problem of lack of knowledge on the WSS buried assets. The main objective of this doctoral work is thus to generate tools and assess their feasibility of application to the characterization of components of WSSs from GPR images. In this work we have carried out laboratory tests specifically designed to propose, develop and evaluate methods for the characterization of the WSS buried components. Additionally, we have conducted field tests, which have enabled us to determine the feasibility of implementing such methodologies under uncontrolled conditions. The methodologies developed are based on techniques of intelligent data analysis. The basic principle of this work has involved the processing of data obtained through the GPR to look for useful information about WSS components, with special emphasis on the pipes. After performing numerous activities, one can conclude that, using GPR images, it is feasible to obtain more information than the typical identification of hyperbolae currently performed. In addition, this information can be observed directly, e.g. more simply, using the methodologies proposed in this doctoral work. These methodologies also prove that it is feasible to identify patterns (especially with the preprocessing algorithm termed Agent race) that provide fairly good approximation of the location of leaks in WSSs. Also, in the case of pipes, one can obtain such other characteristics as diameter and material. The main outcomes of this thesis consist in a series of tools we have developed to locate, identify and visualize WSS components from GPR images. Most interestingly, the data are synthesized and reduced so that the characteristics of the different components of the images recorded in GPR are preserved. The ultimate goal is that the developed tools facilitate decision-making in the technical management of WSSs, and that such tools can even be operated by personnel with limited experience in handling non-destructive methodologies, specifically GPR.
[ES] Con el paso del tiempo, y debido a múltiples actividades operacionales y de mantenimiento, las redes de los sistemas de abastecimiento de agua (SAAs) sufren intervenciones, modificaciones o incluso, son clausuradas, sin que, en muchos casos, estas actividades sean correctamente registradas. El conocimiento de los trazados y características (estado y edad, entre otros) de las tuberías en los SAAs es obviamente necesario para una gestión eficiente y dinámica de tales sistemas. A esta problemática se suma la detección y el control de las fugas de agua. El acceso a información fiable sobre las fugas es una tarea compleja. En muchos casos, las fugas son detectadas cuando los daños en la red son ya considerables, lo que trae consigo altos costes sociales y económicos. En este sentido, los métodos no destructivos (por ejemplo, ground penetrating radar - GPR), pueden ser una respuesta a estas problemáticas, ya que permiten, como se pone de manifiesto en esta tesis, localizar los trazados de las tuberías, identificar características de los componentes y detectar las fugas de agua cuando aún no son significativas. La selección del GPR, en este trabajo se justifica por sus características como técnica no destructiva, que permite estudiar tanto objetos metálicos como no metálicos. Aunque la captura de información con GPR suele ser exitosa, la configuración de la captura, el gran volumen de información, y el uso y la interpretación de la información requieren de alto nivel de habilidad y experiencia por parte del personal. Esta tesis doctoral se plantea como un avance hacia el desarrollo de herramientas que permitan responder a la problemática del desconocimiento de los activos enterrados de los SAAs. El objetivo principal de este trabajo doctoral es, pues, generar herramientas y evaluar la viabilidad de su aplicación en la caracterización de componentes de un SAA, a partir de imágenes GPR. En este trabajo hemos realizado ensayos de laboratorio específicamente diseñados para plantear, elaborar y evaluar metodologías para la caracterización de los componentes enterrados de los SAAs. Adicionalmente, hemos realizado ensayos de campo, que han permitido determinar la viabilidad de aplicación de tales metodologías bajo condiciones no controladas. Las metodologías elaboradas están basadas en técnicas de análisis inteligentes de datos. El principio básico de este trabajo ha consistido en el tratamiento adecuado de los datos obtenidos mediante el GPR, a fin de buscar información de utilidad para los SAAs respecto a sus componentes, con especial énfasis en las tuberías. Tras la realización de múltiples actividades, se puede concluir que es viable obtener más información de las imágenes de GPR que la que actualmente se obtiene con la típica identificación de hipérbolas. Esta información, además, puede ser observada directamente, de manera más sencilla, mediante las metodologías planteadas en este trabajo doctoral. Con estas metodologías se ha probado que también es viable la identificación de patrones (especialmente el pre-procesado con el algoritmo Agent race) que proporcionan aproximación bastante acertada de la localización de las fugas de agua en los SAAs. También, en el caso de las tuberías, se puede obtener otro tipo de características tales como el diámetro y el material. Como resultado de esta tesis se han desarrollado una serie de herramientas que permiten visualizar, identificar y localizar componentes de los SAAs a partir de imágenes de GPR. El resultado más interesante es que los resultados obtenidos son sintetizados y reducidos de manera que preservan las características de los diferentes componentes registrados en las imágenes de GPR. El objetivo último es que las herramientas desarrolladas faciliten la toma de decisiones en la gestión técnica de los SAAs y que tales herramientas puedan ser operadas incluso por personal con una experiencia limitada en el manejo
[CAT] Amb el temps, a causa de les múltiples activitats d'operació i manteniment, les xarxes de sistemes d'abastament d'aigua (SAAs) se sotmeten a intervencions, modificacions o fins i tot estan tancades. En molts casos, aquestes activitats no estan degudament registrats. El coneixement dels camins i característiques (estat i edat, etc.) de les canonades d'aigua i sanejament fa evident la necessitat d'una gestió eficient i dinàmica d'aquests sistemes. Aquest problema es veu augmentat en gran mesura tenint en compte la detecció i control de fuites. L'accés a informació fiable sobre les fuites és una tasca complexa. En molts casos, les fugues es detecten quan el dany ja és considerable, el que porta costos socials i econòmics. En aquest sentit, els mètodes no destructius (per exemple, ground penetrating radar - GPR) poden ser una resposta constructiva a aquests problemes, ja que permeten, com s'evidencia en aquesta tesi, per determinar rutes de canonades, identificar les característiques dels components, i detectar les fuites d'aigua quan encara no són significatives. La selecció del GPR en aquest treball es justifica per les seves característiques com a tècnica no destructiva que permet estudiar tant objectes metàl·lics i no metàl·lics. Tot i que la captura d'informació amb GPR sol ser reeixida, aspectes com ara la configuració de captura, el gran volum d'informació que es genera, i l'ús i la interpretació d'aquesta informació requereix alt nivell d'habilitat i experiència. Aquesta tesi pot ser vista com un pas endavant cap al desenvolupament d'eines capaces d'abordar el problema de la manca de coneixement sobre els actius d'aigua i sanejament enterrat. L'objectiu principal d'aquest treball doctoral és, doncs, generar eines i avaluar la seva factibilitat d'aplicació a la caracterització dels components de los SAAs, a partir d'imatges GPR. En aquest treball s'han dut a terme proves de laboratori específicament dissenyats per proposar, desenvolupar i avaluar mètodes per a la caracterització dels components d'aigua i sanejament soterrat. A més, hem dut a terme proves de camp, que ens han permès determinar la viabilitat de la implementació d'aquestes metodologies en condicions no controlades. Les metodologies desenvolupades es basen en tècniques d'anàlisi intel·ligent de dades. El principi bàsic d'aquest treball ha consistit en el tractament de dades obtingudes a través del GPR per buscar informació útil sobre els components d'SAA, amb especial èmfasi en la canonades. Després de realitzar nombroses activitats, es pot concloure que, amb l'ús d'imatges de GPR, és factible obtenir més informació que la identificació típica d'hipèrboles realitzat actualment. A més, aquesta informació pot ser observada directament, per exemple, més simplement, utilitzant les metodologies proposades en aquest treball doctoral. Aquestes metodologies també demostren que és factible per identificar patrons (especialment el pre-processat amb l'algoritme Agent race) que proporcionen bastant bona aproximació de la localització de fuites en SAAs. També, en el cas de tubs, es pot obtenir altres característiques com ara el diàmetre i el material. Els principals resultats d'aquesta tesi consisteixen en una sèrie d'eines que hem desenvolupat per localitzar, identificar i visualitzar els components dels SAAS a partir d'imatges GPR. El resultat més interessant és que els resultats obtinguts són sintetitzats i reduïts de manera que preserven les característiques dels diferents components registrats en les imatges de GPR. L'objectiu final és que les eines desenvolupades faciliten la presa de decisions en la gestió tècnica de SAA, i que tals eines poden fins i tot ser operades per personal amb poca experiència en el maneig de metodologies no destructives, específicament GPR.
Ayala Cabrera, D. (2015). Characterization of components of water supply systems from GPR images and tools of intelligent data analysis [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/59235
TESIS
Premiado

The increasing demand for water to provide for South Africa's growing population has resulted in increasing pressure being placed on the country's limited water resources. Water developments however cannot be undertaken without considering the water resource base and the key policy frameworks that governs its use and protection. The Department of Water Affairs and Forestry as the custodian of water resources in the country initiated the implementation of the National Water Act during 1999. It has therefore the mandate to ensure that the protection, use, development, conservation, management and control of water resources be achieved in an equitable, efficient and sustainable manner, to the benefit of society at large. The National Water Act prescribes that the Minister of the Department of Water Affairs and Forestry develop a system for the classification of all significant water resources to ensure its protection and sustainable utilisation. The classification system is to be used to determine the class and resource quality objectives of all significant water resources. In the absence of a formal classification system, a framework was developed through this research study in order to guide both the development of a classification system and the implementation, hence ensuring an overarching structure within which intergrated water resource management can be achieved. The main goal of this framework was to seek an appropriate balance between protecting significant water resources and at the same time promoting water resource utilisation in support of socio-economic development. This framework was executed in the preliminary determination of the Reserve for the Thukela River catchment to ensure that informed and calculated decision-making processes are followed once significant water resources are classified.

Thesis (M. Tech.) -- Central University of Technology, Free State, 2007
In South Africa, water is a scarce resource and it has become very important to manage this resource effectively. The State developed a regulating framework, under the hospice of the Minister of Water Affairs and Forestry, which protects the country‟s water resources from over-exploitation by ensuring that it is protected, used, developed, conserved, and managed, in a sustainable and equitable manner. The laws and policies governing the use of water resources are contained in the National Water Act (South Africa, 1998), the National Water Policy (South Africa, 1997a), the National Water Resource Strategy, and the Water Services Act (South Africa, 1997b). In addition some water-related functions were transferred to Catchment Management Agencies and Water Users‟ Associations, and it is their task to ensure that the strategies, laws and policies are implemented. Effective water management can only be performed by making use of hydroinformatics which assists with simulations and estimations. As a result input data will be collected, added to a Relational Database Management System and output results generated. A Geographic Information System with the support of a geodatabase will allow users to store spatial and temporal data. The research project investigated different water-related data models (ArcHydro, Hydstra, GML, HYMOS, and WinHSPF), as well as hydrological modelling frameworks (BASINS, OMS, OpenMI, SPATSIM, and TIME) to determine whether they were adequate to assist with the decision making of water-related activities. It was found that these data models and hydrological modelling frameworks did not allow users to add new datasets to their existing data structures and in many cases only had a limited set of functions. For these reasons it was decided to develop a comprehensive, modifiable, geodatabase that will function in a modelling environment which will allow users to save their data in a centralised database. Additionally the functionality provided by other data models and modelling frameworks may be linked and used in the new modelling environment. A methodology that has been followed was to first establish the objectives of the research project, gather the necessary data, investigate various data models and hydrological modelling frameworks, determine the requirements for the modelling environment, design and create the modelling environment, design and create the geodatabase, and finally selecting the study area which will provide the research project with the necessary data. The following findings were made concerning the research project: firstly, that ArcHydro will be used as example data model to assist in designing the geodatabase. Secondly, that UML will be used as a development tool to assist with the development of the geodatabase. Thirdly, that the geodatabase will be generated from the XML schema and be made available to ArcCatalog. Fourthly, that data from different users/providers (Hydstra, Stats SA, Weather Bureau, Department of Water Affairs and Forestry, etc.) be inserted into the geodatabase. Fifthly, that any other hydrological modelling framework may make use of the data stored in the geodatabase. Finally, ArcGIS was selected as GIS application and Microsoft Access as a storage area.

The main scope of this project is to rebuild and deploy web applications that will help share historical artifacts related to the Santa Ana watershed. This project is designed to give a consistent user interface and add extra tools to enhance the functionality of existing applications at the Water Resources Institute (WRI) at California State University San Bernardino (CSUSB). The purpose of this project is to migrate all applications to a single server and update the applications using ArcGIS Server 9.2. Also to give a consistent look to the applications and to make them user friendly.

This study develops and presents a conceptual framework which builds upon and extends the economics of information literature. Combining observations which emerge from a review of literature concerning organizational decision processes, this framework considers the nature of the demand and value for water resource information by individuals who participate in the decision making process found within public water management organizations. Based upon this conceptual framework the paper reports the results of an empirical model relating decision participant use of the Water Resource Council' s Second National Water Assessment and hypothetical expenditures on "national assessment type information" to personal and agency characteristics in two water basin management situations; instream versus offstream water use competition in the Missouri River basin, and low freshwater inflows to Chesapeake Bay. In addition, results of a contingent ranking investigation designed to estimate marginal water information values are presented and the potential use of the contingent ranking method by agencies in water data collection discussed. Results of the investigations indicate that previous use of specific water information products and the level of expenditures made on certain types of water information are influenced by personal and organizational characteristics. Consequently, there can exist no "correct" information system and thus no "correct" data collection plan in the absence of knowledge concerning information value. Moreover, results indicate that contingent ranking procedures involving items of information may be successfully conducted in a mail survey format and that the information value estimates derived through this technique can be employed to promote greater efficiency in water data investment.
Ph. D.

The objective of this study was to develop a comprehensive, basin-wide, water-quality-planning model using system dynamics methodology. Later, the model was to be interfaced with a more conventional system dynamics model: one simulating social, technological, economic, and political interactions. By doing so, it is envisioned that such management policies as zoning, abatement facilities, and best management practices may be simulated together.

Master of Science

Although oscillating water column type wave energy devices are nearing the stage of commercial exploitation, there is still much to be learnt about many facets of their hydrodynamic performance. This research uses the commercially available FLUENT computational fluid dynamics flow solver to model a complete OWC system in a two dimensional numerical wave tank. A key feature of the numerical modelling is the focus on the influence of the front wall geometry and in particular the effect of the front wall aperture shape on the hydrodynamic conversion efficiency. In order to validate the numerical modelling, a 1:12.5 scale experimental model has been tested in a wave tank under regular wave conditions. The effects of the front lip shape on the hydrodynamic efficiency are investigated both numerically and experimentally and the results compared. The results obtained show that with careful consideration of key modelling parameters as well as ensuring sufficient data resolution, there is good agreement between the two methods. The results of the testing have also illustrated that simple changes to the front wall aperture shape can provide marked improvements in the efficiency of energy capture for OWC type devices.

In order to develop a system that could provide fish farmers with information to monitor stock performance and plan for a timely production, a computerised recording system was designed and tested on a trout hatchery in Scotland. It facilitated routine data capture on site with a small hand-held computer, programmed in BASIC language, which subsequently downloaded the data to a central desk-top microcomputer for further processing. Both direct and long-distance transmission via the telephone network using modems were possible. The LOTUS 1-2-3 general purpose software package, running on the microcomputer, was customised using 'macro' commands to accept the transmitted data and create files for storage on 'floppy' or 'hard' magnetic disks. Further information could be calculated and graphs and summary reports for stock control could be generated at will. Other customised LOTUS worksheets were developed to allow identification and access of specific historical data in order to calibrate regression equations and provide growth predictions for particular fish types. This information combined with cost and pricing details was further utilised by a linear programming package. Guidelines on optimum policies were formulated and sensitivity analyses could be performed. This production information system was implemented on the IBM-PC and the OLIVETTI M24 desk-top microcomputers and as field devices the SHARP PC 1500A and the HUSKY HUNTER were used. Since existing technology and 'off-the-shelf' software were utilised, the developed information system can be easily adjusted to suit the individual needs of different fish farms. However, the most important requirement for successful implementation would be the commitment and enthusiasm of the fish farm manager.

Thesis (M. S.)--Mechanical Engineering, Georgia Institute of Technology, 2010.
Committee Chair: Yogendra K. Joshi; Committee Member: Mostafa Ghiaasiaan; Committee Member: Sheldon Jeter. Part of the SMARTech Electronic Thesis and Dissertation Collection.

The Table Mountain group aquifer system has the potential to be an important supply of water. Although the aquifer system is used to some extent, a number of aspects relating to the aquifer system are poorly understood and unquantified. This study aimed to take into consideration the importance of differenct ecosytems, which is essential in predicting the effects of groundwater abstruction. However, the ecological requirements of systems that depend on groundwater are poorly understood. This project identified "
type areas"
for further detailed research into the impacts of large-scale groundwater abstraction from the Table Mountain group aquifer system based on the nature and functioning of ecosystems across groundwater dependent ecosystem boundaries of a regional scale.

Thesis (Ph. D.)--Ohio State University, 2005.
Title from first page of PDF file. Document formatted into pages; contains xxii, 271 p.; also includes graphics (some col.) Includes bibliographical references (p. 206-214).

In order to preserve groundwater resources from contamination by volatile organic compounds and to clean up sites contaminated with the compounds, we should understand fate and transport of contaminants in the subsurface systems and physicochemical processes involving remediation technologies. To enhance our understanding, numerical studies were performed on the following topics: (i) multiphase flow and contaminant transport in subsurface environments; (ii) biological transformations of contaminants; (iii) in-situ air sparging (IAS); and, thermal-enhanced venting (TEV). Among VOCs, trichloroethylene (TCE) is one of the most-frequently-detected chemicals in the contaminated groundwater. TCE and its daughter products (cis-1,2-dichloroethylene (cDCE) and vinyl chloride (VC)) are chosen as target contaminants. Density-driven advection of gas phase is generated by the increase in gas density due to vaporization of high-molecular weight contaminants such as TCE in the unsaturated zone. The effect of the density-driven advection on fate and transport of TCE was investigated under several environmental conditions involving infiltration and permeability. Biological transformations of contaminants can generate byproducts, which may become new toxic contaminants in subsurface systems. Sequential biotransformations of TCE, cDCE, and VC are considered herein. Under different reaction rates for two bioreaction kinetics, temporal and spatial concentration profiles of the contaminants were examined to evaluate the effect of biotransformations on multispecies transport. IAS injects clean air into the subsurface below the groundwater table to remediate contaminated groundwater. The movement of gas and the groundwater as a multiphase flow in the saturated zone and the removal of TCE by IAS application were analyzed. Each fluid flow under IAS was examined in terms of saturation levels and fluid velocity profiles in a three-dimensional domain. Several scenarios for IAS systems were simulated to evaluate remedial performance of the systems. TEV was simulated to investigate its efficiency on the removal of a nonaqueous phase liquid in the unsaturated zone under different operational conditions. For numerical studies herein, the governing equations for multiphase flow, multispecies transport, and heat energy in porous media were developed and solved using Galerkin finite element method. A three-dimensional numerical model, called TechFlowMP model, has been developed.

Thesis (MSc)--Stellenbosch University, 2005.
ENGLISH ABSTRACT: Water resources in South Africa are limited and groundwater plays an important role in supporting basic human needs, sustaining ecosystems and enabling industrial and agricultural development. Sound management practices are necessary to ensure sustainable development of water resources. All groundwater usage must be licensed in compliance with the National Water Act of 1998. A Spatial Decision Support System (SDSS) can be used to assist in the groundwater usage licensing process of the Department of Water Affairs and Forestry (DWAF). The main aim of this study was to develop a SDSS, named Groundwater Abstraction & Licence Evaluation Tool (GALET), that could assist in the process of allocating water use licences and determining the local impact of abstraction, based on existing theory and data. The development was done within ArcView 3.2 using the scripting language Avenue. The Sandveld, an arid stretch of land along the west coast of South Africa that is heavily impacted by groundwater abstraction, was the chosen study area. The data collected for this study included existing borehole, recharge, rainfall and geological information. GALET proved to be capable of calculating essential information needed to evaluate groundwater abstraction, which included drawdown in the water table, zone of influence and the possible effects on features such as rivers and wetlands. Targeted potential users regarded GALET as a useful tool in the process of licensing and groundwater abstraction impact assessment and plans are under way to implement GALET or a derivative thereof at the DWAF regional offices.
AFRIKAANSE OPSOMMING: Waterhulpbronne in Suid-Afrika is beperk en grondwater speel 'n belangrike rol in die ondersteuning van basiese menslike behoeftes, volhouding van ekosisteme asook industriële en landbou-ontwikkeling. Betroubare bestuurspraktyke is noodsaaklik om die volhoubare ontwikkeling van waterhulpbronne te verseker. Alle grondwatergebruik moet volgens die Nasionale Waterwet van 1998 gelisensieer word. 'n Ruimtelike Besluitnemings Ondersteuning Stelsel (RBOS) kan as 'n hulpmiddel gebruik word in die lisensiëringsproses van die Departement van Waterwese en Bosbou. Die hoofdoel van hierdie studie was om 'n RBOS, genoem Groundwater Abstraction & Licence Evaluation Tool (GALET), te ontwikkel wat as hulpmiddel gebruik kan word in die allokeringsproses van watergebruiklisensies en die bepaling van die impak van grondwateronttrekking op die omgewing, gebaseer op bestaande teorie en data. Die ontwikkeling is in ArcView 3.2 met die programmeringstaal Avenue gedoen. Die Sandveld, 'n ariede streek aan die weskus van Suid-Afrika wat onderhewig is aan grootskaalse grondwateronttrekking, is gekies as die studie area. Die data wat vir hierdie studie ingesamel is sluit bestaande boorgat, grondwateraanvulling, reënval en geologiese inligting in. GALET was in staat om belangrike inligting aangaande die evaluering van grondwateronttrekking te bereken, o.a. die daling van die grondwatervlak, die impaksone en die moontlike effekte op landvorms soos riviere en vleilande. Die teikengroep potensiële gebruikers het GALET as 'n nuttige hulpmiddel in die proses van lisensiëring en grondwateronttrekking impakbepaling beskou en planne is onderweg om dit of 'n aangepaste program by die streekskantore van die Departement van Waterwese en Bosbou te implementeer.

This diploma thesis describes a JSD600 unit intended for mathematical processing, measuring and data recording. The JSD600 unit is highly intended for industrial measuring of water steam energy delivery.First part of the work focuses on basics of the JSD600 unit detailing and describing main structures and principles for relevant data storing.Next part summarizes some basic facts and knowledge from the area of industrial liquid flow, energy measuring and describes water steam states. All these points within this range are needed for dilemma understanding.Last task deals with complete list of communication datagrams, which have been used for communication with JSD600 unit, including a main packet of structure descriptions.The second part of this dissertation brings the unit setup application description including some implementation details of the most interesting parts.

L'évolution libre des fluides géostrophiques turbulents bidimensionnels fait apparaitre des tourbillons présentant une grande cohérence spatio-temporelle. Les écoulements atmosphériques tridimensionnels présentent également ce genre de structures cohérentes, notamment dans les champs de tourbillon potentiel. Certains aspects de la cyclogenèse semblent gouvernés, ou très sensibles, à la position et à l'intensité de ces anomalies. Les images des satellites géostationnaires permettent par ailleurs de visualiser les signatures de ces phénomènes, appelées intrusions sèches. Une première partie du travail adapte des outils de traitement d'image à la détection et au suivi des intrusions sèches sur les images vapeur d'eau. On utilise une approche basée sur des multi-seuillages et le suivi automatisé de structures (logiciel RDT). Le développement de caractéristiques supplémentaires s'avère nécessaire afin de sélectionner les intrusions associées à des événements dynamiques importants. L'une d'entre elles utilise l'information sur le courant-jet à partir de vents d'altitude de l'ébauche. Un deuxième volet s'applique à dégager une méthodologie de correction des structures en tourbillon potentiel à partir de ces informations. L'assimilation de données conventionnelle ne permet pas d'initialiser spécifiquement les structures. Nous décrivons les méthodes alternatives et étudions les possibilités, et limitations, d'une méthodologie basée sur l'assimilation de pseudo-observations. Cela débouche en particulier sur une version renouvelée de la relation entre vapeur d'eau et tourbillon potentiel. Les outils développés sont appliqués à la prévision de la tempête des Landes (2006). L'utilisation de données de concentration d'ozone est finalement évoquée comme une méthode alternative d'initialisation du tourbillon potentiel à la tropopause

M.Ing. (Electrical and Electronic Engineering Science)
Scientific workflows (SWFs) and artificial neural networks (ANNs) have attracted the attention of researchers in many fields and have been used to solve a variety of problems. Examples of these are (a) the use of scientific workflows for the sensor web in the hydrology domain and (b), the use of ANNs for the prediction of a number of water resource variables such as rainfall, flow, water level and various other water quality variables. ANNs have proved to be a powerful tool for prediction when compared with statistical methods. The aims of this research are to develop ANNs that act as predictive models for water resources and to deploy these models as predictive tools in a scientific workflow environment. While there are guidelines in the literature relating to the factors affecting network performance, there is no standard approach that is universally accepted for determining the optimum architecture of a neural network for a given problem. The parameters of a neural network and for the learning algorithm have a major effect on the performance of the neural network. We consider various recurrent and feed-forward neural network architectures for predicting changes in the water levels of dams. We explore various' hidden layer dimensions in learning the characteristics of the training data using the back propagation learning algorithm. Trained networks are deployed as predictive model in a scientific workflows environment called VisTrails. ': We review and discuss the use of SWFs and ANNs in the hydrology domain with emphasis on the development of neural network architecture that will give the best predictions for water resources. A number of architectures are employed to examine the best accurate predictive network for historical rainfall data. The findings of training experiments are promising in terms of the use of ANNs as a water resources predictive tool. Experimental results showed how the architecture of a neural network impacts on its predictive performance. This study shows that the number of hidden nodes is important factor for the improvement of the quality of the predictions.

碩士
國立中山大學
海洋環境及工程學系研究所
104
Nowadays, under water acoustic research applications have been developed widely such as seabed mining, positioning, seafloor geodesy, and stock estimation. According to the research purposes, researchers need to select a suitable acoustic device, such as a single beam echo sounder, a dual beam echo sounder, a side scan sonar, a multi beam echo sounder. For the purpose of protecting, preserving and restoring the marine resources, the Fisheries Agency, Council of Agriculture, Executive Yuan have deployed the artificial reefs around Taiwan coasts over 40 years(1970-2015). Traditionally, most scientists of the fishery acoustics used a scientific echo sounder to investigate the fish stocks, and examing the samples by trawling. But we attempt to use the instrument called Reson SeaBat 7125(which is major used to acquire water depth information in survey area) to record data on acoustic backscatter at Yungan, Kaohsiung. The purpose of this study is to extract the acoustic backscattering strength from fish schools, using the high-resolution and high quality scenes provided by the device. Because the environmental acoustics factors such as fish biological factors, artificial reefs, or reverberation, so we need to exclude the acoustic interferences and extract the signals from fish schools. There are two methodologies could help us extract the signals：(1) we use Fledermaus FMMidwater software to distinguish the types of signal, and then selecting the area of the fish signals, (2) we use the data processing procedure provided by Echoview software to extract the signals of fish. In order to pick up the correct signals, not only examining but confirming is needed. Finally, we capture the acceptable signals of fish, and the results also used to display be displayed in the software calledArcGIS. Because copper calibration test isn’t a suitable method to correct the impulse electrical strength of the Seabat 7125 multi-beam echo sounder, when the device was used to collect water column data, the volume backscattering strength may have some uncertainty. Picking the proper threshold value up is not only an important issue, but also a limitation of this research. The different parameter settings were applied simultaneously, the results demonstrate distinct numbers of fish by the four artificial reefs, which were named right, left, middle and downward. When we use SPSS Statistical Software to analyze data collected from three days, the trending phenomena we found seem to be the identical, most of the fish were detected at the artificial reefs called right, and the summation of the whole day fish numbers has the peak roughly corresponding with dusk and night. Based on the depth depending results, the strong volume backscattering strength signals we extracted, the elevation between these fish schools and artificial reefs is contiguous, and we could find most fish schools around reefs. According to our analyzing results, the elevation was strongly corresponding to the reality water depth, presenting in this study is often 10-15% of the reality water depth. Because “the relationships between schools and reefs” are mentioned, our aim in terms of the demonstration of the linear fish appearing rates was to investigate the schools’ spatial and temporal distribution and the capability of the reefs. Because the fish numbers we detected have the highest values at the right one, although all of the four artificial reefs can keep alive for the fish species, we thought the artificial reef could provide a great deal of shelter than other reefs. Moreover, perhaps the method can’t be a substitution despite against quantification purpose, I assume it can provide a better way of acquire the data around artificial-reef environments.

In the recent years, Global Navigation Satellite Systems (GNSS), in particular Global Positioning Systems (GPS), have proved their capacity to monitor atmospheric water vapor with an accuracy that is comparable to the accuracy of other conventional meteorological sensors. GNSS has several significant advantages compared to the traditional observational systems, including low operating expense, all-weather operability and high temporal/spatial coverage. As a result, the provision of Zenith Total Delay (ZTD) and derived Precipitable Water Vapor (PWV) from GNSS data has become established as a standard and valid technique. These atmospheric parameters are currently assimilated into regional weather forecast models (Meteo Office UK; Meteo France and German Research Center for Geosciences (GFZ)). However, the accuracy of the near realtime estimates for these values is still in active research issue. This dissertation describes the implementation and testing of the estimation of PWV in near-real time that was carried out at SEGAL in framework of the NUVEM project during 2015-2016. The scheme to estimate the atmospheric parameters (ZTD and PWV) and to deliver them timely to the Portuguese Meteo Office (IPMA - Instituto Português do Mar e da Atmosfera) is described in detail. The focus was on the computational component of the scheme but some studies using the estimated solutions were also necessary to be performed in order to obtain some necessary parameters for the operational phase of the project. The timely estimation of the solutions depends of several processes, which needed to be analysed and optimized separately (but considering always their integration in the full schema), namely: • download of the GNSS data from external providers since the project relies on the data acquired by different GNSS networks in Portugal and Spain. • download of the additional products (orbits and clocks) necessary to process the GNSS data. • retrieve from numerical models the values (temperature & pressure) necessary to convert from ZTD to PWV (done at IPMA). • processing of the GNSS solutions as soon as the data and products were available. • uploading of numerical and graphical solutions to IPMA and to the dedicated website. • redundancy of the system in order to guarantee a maximum operational (online) time. Additional features and improvements can be implemented in the future in order to further optimize the use of GNSS-PWV in Portugal for nowcasting. Nevertheless, the goals were achieved since the NUVEM system is currently running in operational mode at SEGAL providing IPMA with timely PWV estimates that can be used to help the analysis of atmospheric events in near-real time.
Nos últimos anos, Sistemas de Navegação Global por Satélite (GNSS), em particular o Sistema de Posicionamento Global (GPS), têm provado a sua capacidade para monitorizar o vapor de agua existente na atmosfera, com uma precisão ao nível de outras soluções mais tradicionais. Este tipo de sistemas tem várias vantagens comparado com os tradicionais sistemas de observação. Entre estas vantagens estão o baixo custo de operacionalização, e a alta cobertura espacial e temporal. Como resultado a previsão de Atraso Total de Zenith (ZTD) e a previsão de Vapor de Água Precipitável (PWV) foi estabelecido como uma técnica de observação standard. ZTDs e PWVs já são hoje em dia utilizados em vários países (nomeadamente Reino Unido, França e Alemanha) como um dos factores que ajuda nos modelos de meteorologia. No entanto, a precisão das estimativas de ZTD/PWV em tempo quase real baseadas em orbitas ultra rápidas do sistema GPS, encontra-se ainda em estudo. Nesta dissertação é descrita a implementação e os testes de validação da computação de PWV em tempo quase real feita pelo SEGAL no âmbito do projecto NUVEM que ocorreu entre 2015 e 2016, o esquema de cálculo dos parâmetros atmosféricos (ZTD e PWV) e o seu envio atempadamente ao Instituto Português do Mar e da Atmosfera (IPMA) é descrito em detalhe. O foco centrou-se na componente informática. No entanto alguns estudos, relativos aos resultados obtidos, foram realizados de forma a poder definir alguns parâmetros necessários na fase operacional do projecto. A computação das soluções está dependente de vários processos. Houve a necessidade destes serem analisados e optimizados separadamente. Eles são: • download dos dados GNSS dos provedores externos, uma vez que o projecto depende desses dados, adquiridos em diferentes redes GNSS em Portugal e Espanha; • download dos dados adicionais (órbitas e relógios) necessários à computação dos dados GNSS; • obtenção via modelos de previsão numérica dos valores de pressão e temperatura necessários para a conversão de ZTD em PWV (feito pelo IPMA); • computação das soluções GNSS tão rápido quanto possível; • upload das soluções (numéricas e gráficas) para o IPMA e para o website; • redundância dos recursos computacionais. Existem funcionalidades e melhorias que podem ser implementadas no futuro de forma a optimizar o uso de GNSS-PWV para o nowcasting em Portugal. Contudo, os objectivos foram atingidos, uma vez que, o sistema NUVEM está em modo operacional, sendo executado no SEGAL e providenciando ao IPMA as soluções que são depois usados na análise de eventos atmosféricos em tempo quase real.

M.Ing.
The aim of this research was to investigate the use of stream processing on the graphics processing unit (GPU) and to apply it into the hydraulic modelling of a water distribution system. The stream processing model was programmed and compared to the programming on the conventional, sequential programming platform, namely the CPU. The use of the GPU as a parallel processor has been widely adopted in many different non-graphic applications and the benefits of implementing parallel processing in these fields have been significant. They have the capacity to perform from billions to trillions of floating-point operations per second using programmable shader programs. These great advances seen in the GPU architecture have been driven by the gaming industry and a demand for better gaming experiences. The computational performance of the GPU is much greater than the computational capability of CPU processors. Hydraulic modelling of water distribution systems has become vital to the construction of new water distribution systems. This is because water distribution networks are very complex and are nonlinear in nature. Further, modelling is able to prevent and anticipate problems in a system without physically building the system. The hydraulic model that was used was the Gradient Method, which is the hydraulic model used in the EPANET software package. The Gradient Method produces a linear system which is both positive-definite and symmetric. The Cholesky method is currently being used in the EPANET algorithm in order to solve the linear equations produced by the Gradient Method. Thus, a linear solution method had to be selected for the use in both parallel processing on the GPU and as a hydraulic network solver. The Conjugate Gradient algorithm was selected as an ideal algorithm as it works well with the hydraulic solver and could be converted into a parallel algorithm on the GPU. The Conjugate Gradient Method is one of the best-known iterative techniques used in the solution of sparse symmetric positive definite linear systems. The Conjugate Gradient Method was constructed both in the sequential programming model and the stream processing model, using the CPU and the GPU respectively on two different computer systems. The Cholesky method was also programmed in the sequential programming model for both of the computer systems. A comparison was made between the Cholesky and the Conjugate Gradient Methods in order to evaluate the two methods relative to each other. The findings in this study have shown that stream processing on the GPU can be used in the parallel GPU architecture in order to perform general-purpose algorithms. The results further affirmed that iterative linear solution methods should only be used for large linear systems.

Examines the susceptibility of existing signal processing methods to errors and identifies other possible causes of depth error not accounted for by existing signal processing methods, by analysis of the detected laser return waveform data. Methods to improve depth accuracy are investigated.
Thesis (M.Eng.Sc.) -- University of Adelaide, Dept. of Electrical and Electronic Engineering, 2002?

A project report submitted to the Faculty of Engineering, University of the Witwatersrand, Johannesburg, in partial fulfilment of the requirements for the degree of Master of Science in Engineering Johannesburg, 1996
Current practice of'the rural water sector in Mozambique does not generally consider all factors that have influenc.eon project sustainability, The urgent need to provide returnees in rural areas with safe water, does not give adequate time to engineers, technicians and those involved in the sector, to conceive and plan a water project property. A Decision Support System (DSS) for rural water supply has been proposed to assist the decision making process to be more systematic, fast and comprehensive. It requires a number of input cata variables which are not difficult to obtain and these variables have been selected to ensure that most aspects inherent in a successful project are considered. The main achievement of this system is the project report, similar to a project preliminary design, and the financial results which are important for project assessment and ranking. The Decision Support System is a computational model which uses engineering and economics approach to combine and process input data and information contained in its database. While the calculation method does not need constant updating, the database has to be verified frequently to produce reliable results. South African prices have been used in the database construction but a correction factor facility was incorporated to adjust and make the model useable in Mozambique. The model has been designed to be used by planners, engineers and technicians, and funding agencies. The model can be used by planners to assess implication of policy decisions on future water supplies and water resources development. For engineers and technicians, the model estimates water demands, project components sizes and quantities, and water source development and reliability. To funding agencies, the model is a tool to determine the best investment scenario of a rural water supply project.

Tese de mestrado integrado, Engenharia Biomédica e Biofísica (Sinais e Imagens Médicas) Universidade de Lisboa, Faculdade de Ciências 2016
Espectroscopia de ressonância magnética (MRS), ao contrário de imagem de ressonância magnética (MRI), permite adquirir informação metabólica em vez de apenas informação morfológica. Imagem de MRS (MRSI) no cérebro permite detetar espectros de múltiplos voxels e, consequentemente, a heterogeneidade espacial de concentrações metabólicas, o que pode ser um indicador de doenças neurológicas e metabólicas. Contudo, MRSI é tecnicamente mais desafiante em campos magnéticos ultra altos havendo algumas limitações que impedem a implementação de MRSI em diagnóstico clínico. Como as concentrações dos metabolitos no corpo são muito mais baixas do que as dos lípidos e, especialmente, da água a sensibilidade de MRS na deteção dos metabolitos é muito mais baixa. Além disso, os sinais da água e dos lípidos são várias ordens de magnitude superiores às dos metabolitos, contaminando o espectro metabólico. Deste modo, é necessário utilizar técnicas de supressão de água e de lípidos. Todavia, devido à heterogeneidade de campo magnético causada por diferenças de suscetibilidade magnéticas nas interfaces ar-tecido, os sinais de água e dos lípidos podem sofrer um desvio da sua frequência, dificultando ainda mais a sua supressão. As técnicas mais usadas para supressão de água são a chemical-shift selective water suppression (CHESS) e a variable pulse power and optimized relaxation delays (VAPOR) que é baseada em CHESS. Embora a CHESS seja mais sensível a heterogeneidades de T1 e de B1, permite tempos de repetição mais curtos do que a VAPOR. No caso dos lípidos, técnicas como supressão de volume exterior (OVS) são muito usadas, porém necessitam de pulsos de radiofrequência (RF) adicionais e gradientes de desfasamento que aumentam o tempo de aquisição. Contudo, desenvolveu-se recentemente uma crusher coil que utiliza uma pequena corrente para gerar gradientes superficiais de desfasamento, criando uma distorção de campo magnético B0 que desfasa o sinal dos lípidos, permitindo tempos de aquisição mais curtos. A resolução espacial em MRSI é limitada não só pela baixa razão sinal-ruido (SNR) dos metabolitos, mas também pelo tempo necessário para codificação em fase das dimensões espaciais. Consequentemente, MRSI adquire-se com amostragem limitada do espaço k para manter tempos de aquisição aceitáveis. Os dados de MRSI necessitam de uma reconstrução com transformada de Fourier (FT) que, devido à amostragem limitada com zero-filling do espaço k, origina efeito de Gibbs ringing. A contaminação de sinal associada a este efeito é chamada de voxel bleeding (vazamento de sinal) e pode ser caracterizada usando a função de resposta ao impulso (PSF). A PSF é descrita por uma função seno cardinal, cuja largura a meia altura do pico principal corresponde ao tamanho efetivo do voxel. A contribuição do sinal pode ser positiva ou negativa e vai diminuindo com a distância à origem da PSF. No caso de a fonte de sinal estar no centro do voxel, não causará contaminação, pois os lobos laterais da função cruzam o valor zero no centro dos voxels adjacentes, ou seja, as contribuições cancelar-se-ão. Caso a fonte esteja localizada na borda do voxel, existirá uma propagação significativa do sinal para os voxels adjacentes. Filtros de apodização do espaço k permitem reduzir os lobos laterais da PSF e, consequentemente, a contaminação. Contudo, aumentam o tamanho efetivo do voxel, diminuindo a resolução espacial efetiva. Várias técnicas para redução de contaminação de lípidos têm sido propostas. Porém, estas apresentam algumas limitações. O objetivo deste estudo é desenvolver um novo método de pós-processamento que permita reduzir a contaminação do sinal dos lípidos extracerebrais nos espectros do cérebro usando conhecimento prévio da PSF. O método desenvolvido foi chamado Reduction of Lipid contamination with Zero-padding (REDLIPZ). Realizaram-se simulações com dados de MRSI simulados para testar o método e adquiriram-se dados de MRSI de fantomas e do cérebro para validação do método. Estes dados foram ainda usados para gerar dados com menor resolução. Utilizaram-se dois fantomas, um contendo água (fantoma de água), acetato, etanol e fosfato, simulando o sinal de metabolitos, e outro contendo óleo de girassol (fantoma de lípidos), simulando o sinal dos lípidos. Apenas no caso dos fantomas, foram feitas aquisições de referência (usando apenas o fantoma de água) onde não se aplicou qualquer supressão. Nas aquisições metabólicas para os fantomas (usando os dois fantomas) e in vivo, utilizou-se supressão de água com CHESS e supressão de lípidos com a crusher coil. Os dados do fantoma foram processados com e sem um filtro de apodização do espaço k, e os dados in vivo apenas com o filtro. Foi efetuada uma remoção do sinal residual da água com pós-processamento e não foi aplicada correção para a heterogeneidade de campo B1. Foram adquiridos mapas de lípidos e dos metabolitos para melhor visualizar alterações espaciais provocadas pelos métodos. Mapas da razão entre os picos dos metabolitos e dos lípidos também foram calculados, ilustrando alterações relativas para verificar se o método tem um maior efeito nos lípidos do que nos metabolitos. Avaliaram-se os espectros de diferentes voxels, um com baixa e outro com alta contaminação mostrando o efeito do método consoante o nível de contaminação. Comparou-se a razão acetato/etanol entre espectros da aquisição de referência (aquisição apenas com o fantoma de água) e da aquisição metabólica (aquisição com ambos os fantomas) para verificar se ambos os picos sofriam alterações de maneira uniforme após aplicação dos métodos. As comparações entre resultados do fantoma processados com e sem filtro mostram o efeito do método em ambos os dados. A comparação dos resultados dos dados originais com os de baixa resolução permite verificar como o método funcionaria com dados de menor resolução. Para este método é necessário assumir previamente que a propagação do sinal dos metabolitos é insignificante e que, por isso, este efeito pode ser desprezado. A utilização de um filtro de apodização do espaço k dificulta o cálculo de uma PSF mais verdadeira. A PSF estimada para os dados do fantoma processados com o filtro, terá lobos laterais diferentes e superiores aos da PSF real apodizada pelo filtro. A presença inesperada de sinal de metabolitos nas regiões correspondentes aos lípidos deve-se aos sinais de água e dos lípidos não totalmente suprimidos. Estes causam distorções da linha de base do espectro e, consequentemente, criam falsos sinais dos metabolitos. As maiores alterações provocadas pelo método nos voxels com maior contaminação, reforçam o facto das contribuições da PSF diminuírem com a distância ao centro da PSF. Verificou-se ainda que os diferentes metabolitos não são afetados uniformemente, porque a PSF difere para as várias ressonâncias. Nos dados de menor resolução foi observada uma menor redução do sinal dos lípidos e maiores artefactos de Gibbs ringing. Estes artefactos estão de acordo com o facto de que a PSF depende da resolução da imagem. Para dados de menor resolução a PSF apresenta lobos laterais maiores. Além disso é mais difícil definir o sinal dos lípidos responsável pela contaminação devido a efeitos de volume parcial e, por essa razão, a PSF produzida será menos precisa. Por último, a heterogeneidade de B1 causa uma variação espacial nos ângulos de nutação. A grande heterogeneidade de sinal deve-se ao facto de não ter sido aplicada uma correção para a heterogeneidade de B1. A correção é necessária no caso de serem feitas comparações diretas entre picos de diferentes metabolitos no espectro. Porém, a correção de B1 não é importante para o cálculo da PSF. A PSF depende da intensidade do sinal e se for aplicada correção de B1 antes de aplicar o método, a intensidade do sinal mudaria, mas a PSF calculada também mudará consoante essa alteração. Trabalho futuro incluirá a combinação dos dados de MRSI com imagens de alta resolução de MRI. Usando a imagem de MRI, o objetivo é realizar uma seleção mais precisa do sinal dos lípidos que realmente geram contaminação melhorando a estimação da PSF destes sinais. Também o perfil de sensibilidade das bobines de receção será tido em conta. A PSF é calculada com uma ponderação relativa à sensibilidade para cada uma das bobines, e no fim é feita uma soma de todas contribuições para cada voxel. Desta forma, produz-se um conhecimento prévio da PSF mais verdadeiro. O método desenvolvido neste estudo permitiu reduzir alguma contaminação dos lípidos em dados de MRSI do cérebro, através da determinação e subtração da PSF destes contaminantes dos espectros contaminados. A redução é benéfica e necessária para deteção e quantificação da concentração corretas dos metabolitos aumentando, assim, a relevância clinica das técnicas de MRSI.
MR spectroscopic (MRS) imaging has relatively low spatial resolution and the reconstruction of the data requires a Fourier transform. As a result, MRS images suffer from an effect referred to as voxel bleeding, whereby residual extra-cranial lipid signals contaminate neighboring voxels. These signals can be one to two orders of magnitude higher than the metabolites, leading to a distortion of metabolite information as well as incorrect detection and quantification. Lipid contamination reduction is necessary to enable quantification of metabolite concentrations, thus, increasing the clinical relevance of MRSI techniques. To this end, our aim was to develop a post-processing method to reduce extra-cerebral lipid tissue signal contamination in the brain tissue spectra. In this work, a new post-processing approach to reduce extra-cerebral tissue lipid signal contamination in the brain tissue spectra by using prior PSF knowledge is presented. A method named REDLIPZ (REDuction of LIPid contamination with Zero-padding) was implemented to assess the PSF knowledge via zero-padding the k-space. The measured PSF of the contaminating lipid signal was later subtracted from the contaminated data. The REDLIPZ produced some reduction of the lipid signal with minimal variations (either an increase or a decrease) in the metabolite resonances both in phantom and in vivo MRSI data acquired at ultra-high field (7T). The reduction of the lipid signal was greater in generated data with lower resolution, however, the changes in the metabolite resonances were also larger. The method was proven to reduce some lipid contamination. This is beneficial for the clinical relevance of MRSI. Combining MRSI with high resolution MR images and taking into account the receiving coil array sensitivity profiles should be both considered for a more precise and truthful measure of the PSF. Further refinement including B1 correction and pre-processing of the MRSI data is required.

M. Tech.
The mechanism of microwave assisted waste oil and water emulsions destabilisation is analysed. The broad overall features of the microwave system to break emulsions are established and the design specifications of each constituent component are set. The type of well suited microwave cavity is selected. After analysis, the multimode cavity proves to be a suitable choice. The established overall dimensions of the cavity are set and used to visualize the field pattern in the treatment chamber. Some MATLAB routines are written and used to enhance the visualization of the field pattern inside the microwave cavity. The individual excited modes are first visualised, followed by the resultant electric field. The detailed descriptions of the drawing are then finalised and the microwave system constituents selected. The cavity is manufactured and tested for leakage. The test shows that the cavity is watertight.

The budgeting of water fluxes in the soil is an extremely complex problem, and is compounded by subsurface controls and environmental forces which modify the soil water dynamics. Of the controlling factors, the underlying geology and the soil media are vital components and are often misinterpreted. The geology and soil media components have been neglected mostly because of the difficulty in monitoring the dominant processes that are linked to the water balance in the subsurface. Until recently, hydrometry has been the dominant method of measuring and monitoring the subsurface water balance. Hydrometric measurements have included water content measurement by Time Domain Reflectometry (TDR), soil water potential measurements through tensiometry and groundwater water level monitoring. Hydrometry is still the preferred method of monitoring soil water dynamics, but measurements are generally localised and lateral accumulations and fluxes of water are difficult to interpret. Using geophysical methods and instrumentation to define soil water dynamics could have numerous advantages over conventional hydrometric methods. Among the geophysical techniques dedicated to image the near surface, Electrical Resistivity Tomography (ERT) surveying has been increasingly used for environmental, engineering and geological purposes during the last decade. The aim of this study is to determine if ERT observations could yield the accuracy required to define vertical and lateral soil water dynamics. The ERT instrumentation uses an electrical current that is inserted into the subsurface through various electrode arrangements and a resulting resistance is determined at the take-out electrodes. With the aid of a modelling package these resistance values are reproduced into a pseudosection of underlying resistivity distribution which is influenced by the moisture conditions of the subsurface medium. This geophysical method is primarily used for geological studies but by doing repeated surveys with the same electrode positioning, moisture fluctuation monitoring could be realised. Use of the ERT technique is at the forefront of soil water dynamics monitoring. The main objective of this study is to propose that the ERT instrumentation could be a more efficient and more informative method of studying soil water dynamics than the traditional soil water dynamics monitoring equipment, particularly to define lateral fluxes and accumulation of subsurface water. The study site is a well instrumented transect in the Nkuhlu Exclosures in the Kruger National Park, South Africa, where ongoing soil water dynamics are monitored. The project aims to compare the ERT data to fiR data on a daily basis, over a period of three weeks, during the rain season, monitoring event based wetting and the subsequent drying phases of the soils in a 2-dimensional section. The project and its fmdings are shown to be valuable to the hydrological interpretation of the subsurface water balance. The application is shown to be particularly important to ecohydrology, in the monitoring of soil water dynamics in a 2-dimensional transect and understanding how the natural cycles of water distribution and plant uptake are linked together. The study demonstrates that ERT can be used to observe changes in the water storage and lateral fluxes within a transect which supports varying vegetation and ecologies. The linking of water fluxes in the hydrology cycle to uptakes and controls in the ecosystem has been developed into the research focus known as ecohydrology The use of the ERT instrument can only benefit this research focus in the future. The study demonstrates that ERT instrumentation can be used to provide valuable understanding of subsurface water dynamics and in turn the effects on ecohydrology.
Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2006.

Computational fluid dynamic (CFO) modelling has been applied to examine the operation of the prc-ozonation system at Wiggins Waterworks, operated by Umgeni Water in Durban, South Africa. Ozonation is employed in water treatment process primarily to achieve the oxidation of iron and manganese, the destruction of micro-organisms and the removal of taste and odour causing compounds. It also aids in the reduction of the colour of the final water, enhancement of algae removal and possible reduction of coagulant demand. A hydrodynamic model has been satisfactorily verified by experimental tracer tests. The effect of the gas injection was modelled by increasing the level of turbulence intensity at the ozone contactor inlet. The model prediction of the overall tracer response corresponded closely to the experimental results. The framework of ozone reaction modelling was subsequently established using values of rate constants from the literature. An accurate prediction of the ozone concentration profile requires the application of the correct ozone kinetics involved. In raw waters, the depletion of ozone is influenced by the presence of natural organic matters (NOM). The observed ozone decay was found in good agreement using the pseudo first-order rate law. By measuring the total organic carbon (TOC) as a surrogate for NOM, the experimentally determined rate constants can be calculated to account for the effects of the ozone doses and the water quality. The characterisation study also aimed to provide sufficient information on ozone depletion and to be operated easily, without the lengthy and costly analyses ofa detailed kinetics study. The predicted profile of residual ozone concentration suggests the current operating strategy can be improved to optimise the ozone utilisation. The proposed monitoring point was suggested to be at the end of second companment where most ozone reactions have been completed. By coupling the transport equations of the target compounds with their chemical reaction rates, the concentration profile of these compounds such as ozone can be predicted in order to assist the understanding of an operation and to attain better interpretation of experimental results.
Thesis (Ph.D.)-University of KwaZulu-Natal, 2005.

The objective of this study was to provide a technique, based on the residence time distribution of a process, for modelling, assessing and improving flow in the processes of water and waste water treatment works. The technique should be accessible to the staff managing and operating the works. From a review of the literature, a preference was given for the experimental method used for determination of the tracer response, including choice of tracer and tracer addition and monitoring. Data analysis techniques were reviewed, and the method of time domain fitting was developed into a computer program, IMPULSE. IMPULSE provided a tool for analysis of residence time data, and removed the constraint of numerical complexity. Using the building blocks of IMPULSE, a realistic flow model can be constructed from tracer data and evaluated. IMPULSE allows a quantitative comparison of models proposed for a process, and provides the parameters of the models. These parameters quantify the non-idealities in a process. A knowledge of the non-idealities provides a basis for decision-making when modifying a process. The results of tracer experiments performed on some water and waste water treatment processes were analysed using IMPULSE. The results showed that collection of good experimental data was critical to the success of the analysis. It is proposed that a guide be produced which draws out the main points raised in the study, including collection of tracer data and use of IMPULSE. The guide should be accessible and easily understandable to the staff managing and operating water and waste water treatment works.
Thesis (M.Sc.Eng.)-University of Natal, Durban, 1995.

Ab initio molecular orbital theory has been successful in predicting the stabilities of many weak complexes; typical of these are the complexes formed between water and various small molecules. To account for the correlation effect, Moller-Plesset perturbation theory truncated at the second order level was employed. In order to account for the hydrogen bonding, the 6-3lG** basis set was used. The geometry optimisations of the complexes were carried out using the Gaussian-92 suite of programs installed on a Hewlett-Packard 720 computer operating under UNIX. The interaction energies of the complexes were subjected to further analysis by applying the Morokuma decomposition scheme. The electrostatic interaction component accounts for over 40% of the total stabilisation energy in all the typical hydrogen bonded complexes. Gas phase enthalpies were computed and compared with the experimental values of similar systems. For the systems studied here, the prediction is that all complexes are stable at 25° C. A second program, Vibra, was used for carrying out a normal coordinate analysis. A third computer program for the graphical representation of molecular and crystallographic models, Schakal-92, was employed to illustrate the predicted equilibrium geometries and the fundamental vibrational modes. The predicted geometries, interaction energies, charge redistributions, vibrational wave numbers, infrared intensities and force constants are listed and compared with those in the literature, where applicable. Correlations between the various predicted properties show some interesting chemistry.
Thesis (Ph.D.)-University of Natal, Durban, 1996.

"February 2003." Corrigenda for, inserted at back Includes bibliographical references (leaves 475-524 ) A methodology is formulated for the successful design and implementation of artificial neural networks (ANN) models for water resources applications. Attention is paid to each of the steps that should be followed in order to develop an optimal ANN model; including when ANNs should be used in preference to more conventional statistical models; dividing the available data into subsets for modelling purposes; deciding on a suitable data transformation; determination of significant model inputs; choice of network type and architecture; selection of an appropriate performance measure; training (optimisation) of the networks weights; and, deployment of the optimised ANN model in an operational environment. The developed methodology is successfully applied to two water resorces case studies; the forecasting of salinity in the River Murray at Murray Bridge, South Australia; and the the forecasting of cyanobacteria (Anabaena spp.) in the River Murray at Morgan, South Australia.

The management of Water Distribution Systems (WDSs) involves making decisions about various operations in the network, including the scheduling of pump operations and setting of disinfectant dosing rates. There are often conflicting objectives in making these operational decisions, such as minimising costs while maximising the quality of the water supplied. Hence, the operation of WDSs can be very difficult, and there is generally considerable scope to improve the operational efficiency of these systems by improving the associated decision making process. In order to achieve this goal, optimisation methods known as Genetic Algorithms (GAs) have been successfully adopted to assist in determining the best possible solutions to WDS optimisation problems for a number of years. Even though there has been extensive research demonstrating the potential of GAs for improving the design and operation of WDSs, the method has not been widely adopted in practice. There are a number of reasons that may contribute to this lack of uptake, including the following difficulties: (a) developing an appropriate fitness function that is a suitable description of the objective of the optimisation including all constraints, (b) making decisions that are required to select the most appropriate variant of the algorithm, (c) determining the most appropriate parameter settings for the algorithm, and (d) a reluctance of WDS operators to accept new methods and approaches. While these are all important considerations, the correct selection of GA parameter values is addressed in this thesis. Common parameters include population size, probability of crossover, and probability of mutation. Generally, the most suitable GA parameters must be found for each individual optimisation problem, and therefore it might be expected that the best parameter values would be related to the characteristics of the associated fitness function. The result from the work undertaken in this thesis is a complete GA calibration methodology, based on the characteristics of the optimisation problem. The only input required by the user is the time available before a solution is required, which is beneficial in the WDS operation optimisation application considered, as well as many others where computationally demanding model simulations are required. Two methodologies are proposed and evaluated in this thesis, one that considers the selection pressure based on the characteristics of the fitness function, and another that is derived from the time to convergence based on genetic drift, and therefore does not require any information about the fitness function characteristics. The proposed methodologies have been compared against other GA calibration methodologies that have been proposed, as well as typical parameter values to determine the most suitable method to determine the GA parameter values. A suite of test functions has been used for the comparison, including 20 complex mathematical optimisation problems with different characteristics, as well as realistic WDS applications. Two WDS applications have been considered: one that has previously been optimised in the literature, the Cherry Hills-Brushy Plains network; and a real case study located in Sydney, Australia. The optimisation problem for the latter case study is to minimise the pumping costs involved in operating the WDS, subject to constraints on the system, including minimum disinfectant concentrations. Of the GA calibration methods compared, the proposed calibration methodology that considered selection pressure determined the best solution to the problem, producing a 30% reduction in the electricity costs for the water utility operating the WDS. The comparison of the different calibration approaches demonstrates three main results: 1. that the proposed methodology produced the best results out of the different GA calibration methods compared; 2. that the proposed methodology can be applied in practice; and 3. that a correctly calibrated GA is very beneficial when solutions are required in a limited timeframe.
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Thesis (Ph.D.) - University of Adelaide, School of Civil, Environmental and Mining Engineering, 2008

The management of Water Distribution Systems (WDSs) involves making decisions about various operations in the network, including the scheduling of pump operations and setting of disinfectant dosing rates. There are often conflicting objectives in making these operational decisions, such as minimising costs while maximising the quality of the water supplied. Hence, the operation of WDSs can be very difficult, and there is generally considerable scope to improve the operational efficiency of these systems by improving the associated decision making process. In order to achieve this goal, optimisation methods known as Genetic Algorithms (GAs) have been successfully adopted to assist in determining the best possible solutions to WDS optimisation problems for a number of years. Even though there has been extensive research demonstrating the potential of GAs for improving the design and operation of WDSs, the method has not been widely adopted in practice. There are a number of reasons that may contribute to this lack of uptake, including the following difficulties: (a) developing an appropriate fitness function that is a suitable description of the objective of the optimisation including all constraints, (b) making decisions that are required to select the most appropriate variant of the algorithm, (c) determining the most appropriate parameter settings for the algorithm, and (d) a reluctance of WDS operators to accept new methods and approaches. While these are all important considerations, the correct selection of GA parameter values is addressed in this thesis. Common parameters include population size, probability of crossover, and probability of mutation. Generally, the most suitable GA parameters must be found for each individual optimisation problem, and therefore it might be expected that the best parameter values would be related to the characteristics of the associated fitness function. The result from the work undertaken in this thesis is a complete GA calibration methodology, based on the characteristics of the optimisation problem. The only input required by the user is the time available before a solution is required, which is beneficial in the WDS operation optimisation application considered, as well as many others where computationally demanding model simulations are required. Two methodologies are proposed and evaluated in this thesis, one that considers the selection pressure based on the characteristics of the fitness function, and another that is derived from the time to convergence based on genetic drift, and therefore does not require any information about the fitness function characteristics. The proposed methodologies have been compared against other GA calibration methodologies that have been proposed, as well as typical parameter values to determine the most suitable method to determine the GA parameter values. A suite of test functions has been used for the comparison, including 20 complex mathematical optimisation problems with different characteristics, as well as realistic WDS applications. Two WDS applications have been considered: one that has previously been optimised in the literature, the Cherry Hills-Brushy Plains network; and a real case study located in Sydney, Australia. The optimisation problem for the latter case study is to minimise the pumping costs involved in operating the WDS, subject to constraints on the system, including minimum disinfectant concentrations. Of the GA calibration methods compared, the proposed calibration methodology that considered selection pressure determined the best solution to the problem, producing a 30% reduction in the electricity costs for the water utility operating the WDS. The comparison of the different calibration approaches demonstrates three main results: 1. that the proposed methodology produced the best results out of the different GA calibration methods compared; 2. that the proposed methodology can be applied in practice; and 3. that a correctly calibrated GA is very beneficial when solutions are required in a limited timeframe.
Thesis (Ph.D.) - University of Adelaide, School of Civil, Environmental and Mining Engineering, 2008

Streamflow data are critical for water resource investigations, and their development projects. However, the scarcity of such data, particularly measured streamflow through streamflow gauges, constitutes a serious impediment to the successful implementation of development projects. In the absence of such measured streamflow data, streamflow estimation using measured meteorological data represents a viable alternative. Nevertheless, this alternative is not always possible due to the unavailability of required meteorological data. In the face of such data limitations, many have advocated the use of remote sensing (RS) data to estimate streamflow. The aim of this study was to generate daily streamflow time series data using remote sensing data through catchment process modelling and statistical modelling.

South African water management areas could find themselves without enough water for its users due to new methods of performing water allocation as stipulated in the National Water Act of 1998. A water accounting system would address the need for accurate metering, monitoring and auditing of South Africa’s water resources to ensure that users are complying with their allocations. Such a system should be able to provide information such as comparisons between the simulated and observed flow of water at a point, comparisons between the amount of water allocated to a user and the actual water used by that user, and the source and destination of water at a point. This document contains a literature review, an explanation of the methods used to develop a prototype water accounting system and a discussion of the results from testing the system. A literature review was undertaken which covered topics in water resources planning, water resources operations, local legislation for water allocation and new technologies which could be applied to aid the management of water resources in South Africa. The results from the literature review indicated real time water accounting systems can give effect to water allocation rules. The water accounting system is comprised of two simulation models and a database. The models used for the study were the ACRU2000 model and the MIKE BASIN model. These models require data as well as a means to automate the transfer of data between the models and thus a database was developed. The database was developed in Microsoft Access and, in addition to the construction of a number of tables required to house the data, a database dashboard was made to control the functions of the database. An assessment of the ACRU2000 and MIKE BASIN models was performed in order to determine if they are suitable for use as water accounting tools. ACRU2000 was used for its process based, daily rainfall-runoff modelling capabilities. Due to the process based modelling capabilities of ACRU2000, forecasts of rainfall can be used as input to the simulations. Hot starting is the storing of internal model state variables at a particular time and the use of these variables in a different simulation to start the model up again. It was expected that, due to long simulation run times for ACRU2000, it would be beneficial to enable ACRU2000 to be hot started and an attempt to hot start ACRU2000 is presented. This would have allowed for significantly decreased simulation run times as the model can be warmed up for two years and thereafter hot started to run only for one day at a time. An assessment of the MIKE BASIN network allocation model to be used as a water accounting system was performed by attempting to meet the project objectives through building a fictional water supply network. The network is composed of a small catchment containing six runoff generating regions, a reservoir and ten water users. Three network allocation scenarios were constructed in order to fully test the rule sets and allocation capabilities currently available in the MIKE BASIN model. The study has shown that the tools and models used are capable of forming a rudimentary water accounting system. This is encouraging as it shows that there is the potential to improve the water resources management in South Africa using tools that already exist.
Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2010.

Includes bibliographical references (64 p.)
2 v. : ill., maps (chiefly col.) ; 30 cm.
Title page, contents and abstract only. The complete thesis in print form is available from the University Library.
The concept of sustainable development is explored with a focus upon water resources and urban development. Simulation of urban growth patterns and water resources management has been undertaken as part of the case study. The artificial Neural Networks technique has been employed to model regional water consumption.
Thesis (Ph.D.)--University of Adelaide, Dept. of Civil and Environmental Engineering, 1999?

Historical water quality databases from two South Australian drinking water reservoirs were used, in conjunction with various computational modelling methods for the ordination, clustering and forecasting of complex ecological data. Techniques used throughout the study were: Kohonen artificial neural networks (KANN) for data categorisation and the discovery of patterns and relationships, recurrent supervised artificial neural networks (RANN) for knowledge discovery and forecasting of algal dynamics and hybrid evolutionary algorithms (HEA) for rule-set discovery and optimisation for forecasting algal dynamics. These methods were combined to provide an integrated approach to the analysis of algal populations including interactions within the algal community and with other water quality factors, which results in improved understanding and forecasting of algal dynamics. The project initially focussed on KANN for the patternising and classification of the historical data to reveal links between the physical, chemical and biological components of the reservoirs. This offered some understanding of the system and relationships being considered for the construction of the forecasting models. Specific investigations were performed to examine past conditions and the impacts of different management regimes, as well as to discover sets of conditions that correspond with specific algal functional groups. RANN was then used to build models for forecasting both Chl-a and the main nuisance species, Anabaena, up to 7 days in advance. This method also provided sensitivity analyses to demonstrate the relationship between input and output variables by plotting the reaction of the output to variations in the inputs. Initially one year from the data set was selected for the testing of a model, as per the split-sample technique. To further test the models, it was later decided to select several years for testing to ensure the models were useful under changed conditions, and that test results were not misleading regarding the models true capabilities. RANN were firstly used to create reservoir specific or ad-hoc models. Later, the models were trained with the merged data sets of both reservoirs to create one model that could be applied to either reservoir. Another method of forecasting was trialled and compared to RANN. HEA was found to be equal or superior to RANN in predictive power, also allowed sensitivity analysis and provided an explicit, portable rule set. The HEA rule sets were initially tested on selected years of data, however to fully demonstrate the models potential, a process for k-fold cross-validation was developed to test the rule-set on all years of data. To further extend the applicability of the HEA rule-set; the idea of rule-based agents for specific lake ecosystem categories was examined. The generality of a rule-based agent means that, after successful validation on several lakes from one category, the agent could then be applied to other water bodies from within that category that had not been involved in the training process. The ultimate test of the rule-based agent for the warm monomictic and eutrophic lake ecosystem category was to be applied to a real-time monitoring and forecasting situation. The agent was fed with online, real-time data from a reservoir that belonged to the same ecosystem category but was not used in the training process. These preliminary experiments showed promising results. It can be concluded that the concept of rulebased agents will facilitate real-time forecasting of algal blooms in drinking water reservoirs provided on-line monitoring of relevant variables has been implemented. Contributions of this research include: (1) to offer insight into the capabilities of 3 kinds of computational modelling techniques applied to complex water quality data, (2) novel applications of KANN including the division of data into separate management periods for comparison of management efficiency, (3) to both qualitatively and quantitatively elucidate relationships between water quality parameters, (4) research toward the development of a forecasting tool for algal abundance 7 days in advance that could be generic for a particular lake ecosystem category and implemented in real-time, and (5) to suggest a thorough testing method for such models (k-fold cross validation).
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Thesis (Ph.D.) -- University of Adelaide, School of Earth and Environmental Sciences, 2008

Historical water quality databases from two South Australian drinking water reservoirs were used, in conjunction with various computational modelling methods for the ordination, clustering and forecasting of complex ecological data. Techniques used throughout the study were: Kohonen artificial neural networks (KANN) for data categorisation and the discovery of patterns and relationships, recurrent supervised artificial neural networks (RANN) for knowledge discovery and forecasting of algal dynamics and hybrid evolutionary algorithms (HEA) for rule-set discovery and optimisation for forecasting algal dynamics. These methods were combined to provide an integrated approach to the analysis of algal populations including interactions within the algal community and with other water quality factors, which results in improved understanding and forecasting of algal dynamics. The project initially focussed on KANN for the patternising and classification of the historical data to reveal links between the physical, chemical and biological components of the reservoirs. This offered some understanding of the system and relationships being considered for the construction of the forecasting models. Specific investigations were performed to examine past conditions and the impacts of different management regimes, as well as to discover sets of conditions that correspond with specific algal functional groups. RANN was then used to build models for forecasting both Chl-a and the main nuisance species, Anabaena, up to 7 days in advance. This method also provided sensitivity analyses to demonstrate the relationship between input and output variables by plotting the reaction of the output to variations in the inputs. Initially one year from the data set was selected for the testing of a model, as per the split-sample technique. To further test the models, it was later decided to select several years for testing to ensure the models were useful under changed conditions, and that test results were not misleading regarding the models true capabilities. RANN were firstly used to create reservoir specific or ad-hoc models. Later, the models were trained with the merged data sets of both reservoirs to create one model that could be applied to either reservoir. Another method of forecasting was trialled and compared to RANN. HEA was found to be equal or superior to RANN in predictive power, also allowed sensitivity analysis and provided an explicit, portable rule set. The HEA rule sets were initially tested on selected years of data, however to fully demonstrate the models potential, a process for k-fold cross-validation was developed to test the rule-set on all years of data. To further extend the applicability of the HEA rule-set; the idea of rule-based agents for specific lake ecosystem categories was examined. The generality of a rule-based agent means that, after successful validation on several lakes from one category, the agent could then be applied to other water bodies from within that category that had not been involved in the training process. The ultimate test of the rule-based agent for the warm monomictic and eutrophic lake ecosystem category was to be applied to a real-time monitoring and forecasting situation. The agent was fed with online, real-time data from a reservoir that belonged to the same ecosystem category but was not used in the training process. These preliminary experiments showed promising results. It can be concluded that the concept of rulebased agents will facilitate real-time forecasting of algal blooms in drinking water reservoirs provided on-line monitoring of relevant variables has been implemented. Contributions of this research include: (1) to offer insight into the capabilities of 3 kinds of computational modelling techniques applied to complex water quality data, (2) novel applications of KANN including the division of data into separate management periods for comparison of management efficiency, (3) to both qualitatively and quantitatively elucidate relationships between water quality parameters, (4) research toward the development of a forecasting tool for algal abundance 7 days in advance that could be generic for a particular lake ecosystem category and implemented in real-time, and (5) to suggest a thorough testing method for such models (k-fold cross validation).
Thesis (Ph.D.) -- University of Adelaide, School of Earth and Environmental Sciences, 2008

The objective of this project was to develop a suitable procedure for the design, control and optimisation of the Tubular Filter Press. To this end, the following objectives were defined for this study: • To extend or improve upon the constant pressure compressible cake filtration model, predictive solution procedure, and standard laboratory characterisation techniques requlred to obtain the empirical model parameters, presented in Rencken (1992). A new generalised area contact constant pressure compressible cake filtration model was developed for both the internal cylindrical and planar filtration geometries. The model utilises a heuristically developed area contact function which relates the interparticle contact area to the solids compressive pressure within the cake. If the area contact is zero, the model reduces to the conventional point contact model as presented in Rencken ( 1992). The sludge used in this investigation was found to exhibit a negligible degree of area contact. A new pseudo variable pressure solution procedure was developed, that is an extension of the constant pressure solution procedure, to account for the initial variable pressure stage of the Tubular Filter Press operation. The pseudo variable pressure solution procedure was found to account accurately for the initial filtration behaviour observed during the pressurisation period of the Tubular Filter Press. However for the normal operation of the Tubular Filter Press. the difference between the output of the pseudo variable pressure and constant pressure solution procedures, was found to be insignificant. Wall friction in compression-permeability (C-P) cell tests was identified as a main source of error. The significance of wall friction was investigated using a specially constructed C-P cell. that enabled the transmitted pressure through the cake sample to be measured. The accuracy of the characterisation which had been corrected for the effects of wall friction, was found to improve the prediction of the filtration behaviour of the sludge significantly. The direct shear test was identified and documented as a feasible experimental procedure to determine the coefficient of earth pressure at rest. The coefficient of earth pressure is unique to the non-planar filtration geometries. The coefficient of earth pressure at rest was determined for the sludge used in this investigation. • To incorporate the constant pressure compressible cake filtration model and the associated predictive solution procedures into a user-friendly computer programme that will facilitate the design and optimisation of full-scale plants. The predictive solution procedures were incorporated into the Windows 95 computer programme, COMPRESS, that can be used for any constant pressure compressible cake dead-end filtration application where the filtration geometry is planar or internal cylindrical. A control and optimisation strategy for the continuous operation of the Tubular Filter Press has been proposed. To develop a regressive solution procedure, and incorporate this procedure into a user-friendly computer progranune, that will enable the empirical model parameters. normally obtained from standard laboratory-scale tests, to be obtained from actual filtration data. A regressive solution procedure was developed that utilises a direct search optimisation technique that is an extension of the COMPLEX method. The regressive solution procedure was incorporated into the Windows 95 program, REGRESS. The program utilises filtration data from any dead-end constant pressure filtration application of either planar or internal cylindrical geometry. REGRESS provides an effective means for determining the true physical or plant specific filtration characteristics of the sludge. The regressive solution procedure also enables the parameters specific to the new area contact model to be determined. The sludge characterisation obtained from regressing on filtration data was found to be a significant improvement in predicting the filtration behaviour, than the characterisation obtained from the standard non-filtration laboratory-scale methods, even after the C-P cell data had been corrected for the effects of wall friction. The programs COMPRESS and REGRESS should greatly assist in the design. control and optimisation of the Tubular Filter Press process.
Thesis (M.Sc.Eng.)-University of Natal, Durban, 2000.

In South Africa, government (Mbeki 1996:37) and educators (SAIDE Report 1998:9) have expressed concern over the provision of microcomputers for learners. Their provision to schools would allow their effective use across the curriculum and enhance education. This study investigated the role of microcomputers as information retrieval tools in the 1997 schools' Water Audit projects in the greater Pietermaritzburg area. The study considered, firstly, a discussion of environmental education with emphasis on water conservation, and secondly the Water Audit projects. An overview of issues relating to microcomputer systems as information retrieval tools in education was presented. A descriptive survey method was employed for the study, with questionnaires as the data collection technique. Thirty out of 40 teachers/school project co-ordinators were sampled, with a 24 (80%) response. Twenty percent of 550 pupils who participated in the projects also responded. Data was presented by the use of tables. The study revealed an unequal availability of microcomputers among the schools in the departments of education, as they existed prior to 1994, that participated in the projects. Findings also revealed that only a minority of pupils used the microcomputer system for information retrieval during the projects. The use of hard copy sources was significantly high within the departments. A high number of pupils who used the microcomputer found it useful. A higher number that used hard copy sources found them useful. Training of pupils to acquire computer and information skills was inadequate. Major problems encountered during the projects included congestion, lack of computer skills on the part of both teachers and pupils and inadequate training of participants. The study found infrastructural backlogs and logistical problems as hindrances to the delivery of education in South Africa using microcomputers. Non-involvement of media teachers negatively impacted on the results of the projects. It was recommended that schools without microcomputers liaise with donor agencies to acquire microcomputers, while government initiates policies to address the issue of equity. Educators and media teachers should be given concerted training in computer and information skills, as training underpins the use of microcomputers in an information age school.
Thesis (MIS)-University of Natal, Pietermaritzburg, 1999.

A Pipeline Analytical Program and Dredging Knowledge{Base Expert{System (DKBES) determines a pipeline dredge's production and resulting cost and schedule. Pipeline dredge engineering presents a complex and dynamic process necessary to maintain navigable waterways. Dredge engineers use pipeline engineering and slurry transport principles to determine the production rate of a pipeline dredge system. Engineers then use cost engineering factors to determine the expense of the dredge project. Previous work in engineering incorporated an object{oriented expert{system to determine cost and scheduling of mid{rise building construction where data objects represent the fundamental elements of the construction process within the program execution. A previously developed dredge cost estimating spreadsheet program which uses hydraulic engineering and slurry transport principles determines the performance metrics of a dredge pump and pipeline system. This study focuses on combining hydraulic analysis with the functionality of an expert{system to determine the performance metrics of a dredge pump and pipeline system and its resulting schedule. Field data from the U.S. Army Corps of Engineers pipeline dredge, Goetz, and several contract daily dredge reports show how accurately the DKBES can predict pipeline dredge production. Real{time dredge instrumentation data from the Goetz compares the accuracy of the Pipeline Analytical Program to actual dredge operation. Comparison of the Pipeline Analytical Program to pipeline daily dredge reports shows how accurately the Pipeline Analytical Program can predict a dredge project's schedule over several months. Both of these comparisons determine the accuracy and validity of the Pipeline Analytical Program and DKBES as they calculate the performance metrics of the pipeline dredge project. The results of the study determined that the Pipeline Analytical Program compared closely to the Goetz eld data where only pump and pipeline hydraulics a ected the dredge production. Results from the dredge projects determined the Pipeline Analytical Program underestimated actual long{term dredge production. Study results identi ed key similarities and di erences between the DKBES and spreadsheet program in terms of cost and scheduling. The study then draws conclusions based on these ndings and o ers recommendations for further use.

Dissertação de mestrado em Sistemas de Dados e Processamento Analítico
A garantia da qualidade da água para consumo humano constitui um elemento essencial das políticas de saúde pública. A monitorização da qualidade da água em Estações de Tratamento de Água assenta em métodos analíticos cada vez mais sofisticados e eficientes, dispondo de mecanismos que registam automaticamente valores fiáveis dos diversos parâmetros que condicionam a qualidade da água. Face ao volume de dados armazenados, é necessário dotar as instituições de meios tecnologicamente avançados que proporcionem aos seus utilizadores, não só um acesso rápido a informação de qualidade, mas também a capacidade para realizar a sua análise e visualização à medida das suas necessidades. A proposta do desenvolvimento de um sistema de suporte à decisão para a análise da qualidade da água numa Estação de Tratamento de Água, objecto desta dissertação, tem como objectivo a recolha, fornecimento de estruturas e meios para a exploração multidimensional dos dados, bem como a sua classificação e consequente geração de modelos através de mecanismos de Data Mining. Em relação aos mecanismos de Data Mining, é proposta uma abordagem para a previsão da qualidade da água, recorrendo à identificação de alguns modelos de previsão, explorando a utilização de árvores de decisão para tarefas de classificação, que permitam antever possíveis situações de risco no que diz respeito à qualidade da água, analisando assim as mais-valias da utilização de técnicas de Data Mining neste domínio de aplicação. Os resultados obtidos com as experiências realizadas permitem concluir que este estudo poderá ser bastante útil para os responsáveis da área, contribuindo assim para o desenvolvimento de ferramentas automáticas de apoio à tomada de decisão.
The guarantee of the water quality for human consumption is an essential element of the public health politics. Monitoring the quality water in the treatment stations is based on analytical methods which are more and more sophisticated and efficient using mechanisms that automatically register reliable data from the diverse parameters which influence the quality of the water. Taking into account the amount of stored data, it is essential to provide the institutions with high technological means that will give the users, not only a quick access to information of quality, but also the capacity of making an analysis, as well as a visualization regarding their needs. The proposal of developing a decision support system for the analysis of the water quality in a water treatment unit, which is the subject of this thesis, aims at collecting, providing structures and means for the multidimensional exploration of the data, as well as its classification and at the subsequent appearance of models through the mechanisms of Data Mining. In relation to the mechanisms of Data Mining, we suggest an approach for the prevision of water quality, using the identification of some models of prevision, resorting to the exploration of decision trees for the classification that allows us to foresee some possible risky situations as far as the quality of water is concerned and analysing the benefits of the usage of the Data Mining techniques in this domain. The results obtained from these experiments allow us to conclude that this study may be useful to those responsible in the area and contributing for development of tools which are essential for the decision-making.

Indiana University-Purdue University Indianapolis (IUPUI)
The primary objective of this research involves mapping out and validating the existence of sub surface drainage tiles in a given cropland using Remote Sensing and GIS methodologies. The process is dependent on soil edge differentiation found in lighter versus darker IR reflectance values from tiled vs. untiled soils patches. Data is collected from various sources and a primary classifier is created using secondary field variables such as soil type, topography and land Use and land cover (LULC). The classifier mask reduces computational time and allows application of various filtering algorithms for detection of edges. The filtered image allows an efficient feature recognition platform allowing the tile drains to be better identified. User defined methods and natural vision based methodologies are also developed or adopted as novel techniques for edge detection. The generated results are validated with field data sets which were established using Ground Penetration Radar (GPR) studies. Overlay efficiency is calculated for each methodology along with omission and commission errors. This comparison yields adaptable and efficient edge detection techniques which can be used for similar areas allowing further development of the tile detection process.