In this work, data quality control and mitigation tools have been developed for improving the accuracy of photovoltaic (PV) system performance assessment. These tools allow to demonstrate the impact of ignoring erroneous or lost data on performance evaluation and fault detection. The work mainly focuses on residential PV systems where monitoring is limited to recording total generation and the lack of meteorological data makes quality control in that area truly challenging. Main quality issues addressed in this work are with regards to wrong system description and missing electrical and/or meteorological data in monitoring. An automatic detection of wrong input information such as system nominal capacity and azimuth is developed, based on statistical distributions of annual figures of PV system performance ratio (PR) and final yield. This approach is specifically useful in carrying out PV fleet analyses where only monthly or annual energy outputs are available. The evaluation is carried out based on synthetic weather data which is obtained by interpolating from a network of about 80 meteorological monitoring stations operated by the UK Meteorological Office. The procedures are used on a large PV domestic dataset, obtained by a social housing organisation, where a significant number of cases with wrong input information are found. Data interruption is identified as another challenge in PV monitoring data, although the effect of this is particularly under-researched in the area of PV. Disregarding missing energy generation data leads to falsely estimated performance figures, which consequently may lead to false alarms on performance and/or the lack of necessary requirements for the financial revenue of a domestic system through the feed-in-tariff scheme. In this work, the effect of missing data is mitigated by applying novel data inference methods based on empirical and artificial neural network approaches, training algorithms and remotely inferred weather data. Various cases of data loss are considered and case studies from the CREST monitoring system and the domestic dataset are used as test cases. When using back-filled energy output, monthly PR estimation yields more accurate results than when including prolonged data gaps in the analysis. Finally, to further discriminate more obscure data from system faults when higher temporal resolution data is available, a remote modelling and failure detection framework is ii developed based on a physical electrical model, remote input weather data and system description extracted from PV module and inverter manufacturer datasheets. The failure detection is based on the analysis of daily profiles and long-term PR comparison of neighbouring PV systems. By employing this tool on various case studies it is seen that undetected wrong data may severely obscure fault detection, affecting PV system s lifetime. Based on the results and conclusions of this work on the employed residential dataset, essential data requirements for domestic PV monitoring are introduced as a potential contribution to existing lessons learnt in PV monitoring.

Em um ambiente caracterizado pela elevação dos níveis de competitividade e surgimento de demandas mais complexas para a manutenção das instituições, cresce a consciência de que as abordagens convencionais para o tratamento da avaliação de desempenho não são mais suficientes. O cenário atual requer que se lance mão de ferramentas capazes de tratar essa questão com a devida atenção, utilizando, por exemplo, análises multidimensionais e referenciamento de unidades eficientes através do estabelecimento de benchmarkings. Este trabalho procura chamar a atenção da comunidade acadêmica para uma técnica capaz de auxiliar na obtenção de resultados satisfatórios para essa questão: a Análise Envoltória de Dados, ou DEA, disseminando-a como técnica a ser utilizada na realização de estudos que objetivem verificar a eficiência relativa das unidades sob análise através da proposição de uma sistemática de apoio à sua aplicação. Partindo-se de uma revisão que busca elucidar aspectos a respeito da importância de despenderem-se esforços com o estabelecimento de um conjunto de indicadores de desempenho adequado àquilo que, de fato, precisa ser medido, chega-se a um breve apanhado a respeito das principais técnicas de análise multicriterial utilizadas na avaliação de desempenho, com destaque para o Método de Análise Hierárquica - AHP - e a DEA. Especificamente quanto à DEA, foco deste trabalho, são abordadas, além dos modelos tradicionais que consideram retornos constantes e variáveis à escala de produção, respectivamente CCR e BCC, também algumas evoluções sobre os mesmos, considerando a atribuição de restrições aos pesos das variáveis, como no cone-ratio DEA, e a eliminação do eventual empate registrado entre unidades consideradas eficientes, caso do cross-efficiency e do super-efficiency DEA. Em seguida, procede-se à elaboração da sistemática para a utilização da DEA, núcleo deste trabalho, a qual consiste numa seqüência de passos a ser seguida com o intuito de viabilizar a aplicação da análise envoltória de dados em situações de naturezas distintas. A aplicação da sistemática se dá através do estudo de dois casos. No primeiro, tendo por objetivo sugerir uma nova forma de avaliar o desempenho dos países do globo tendo em vista o seu grau de sustentabilidade, 76 nações são avaliadas segundo as perspectivas social, econômica e ambiental, resultando na proposição de um indicador consolidado, o Grau de Sustentabilidade Nacional, ou GSN. No caso subseqüente, ao estudar-se as companhias de transporte aéreo de passageiros, objetiva-se identificar aquelas operacionalmente mais eficientes de acordo com seu porte de operação, resultando na identificação de uma certa influência quanto à origem geográfica das companhias sobre o desempenho apresentado, embora não se tenham identificado indícios de que afiliação a uma das grandes alianças globais também cause alguma influência no resultado. As aplicações conduzidas neste trabalho evidenciam a potencialidade de uso da DEA como ferramenta para a avaliação do desempenho sob uma perspectiva multicriterial em cenários distintos. / In an environment characterized by the raise in competitiveness levels and the emergence of more complex demands to deal with current issues, people get more conscious about the insufficiency of ordinary approaches for performance appraisal. The current scenery demands analysts to use a set of tools that are able to handle this issue with the required attention, for example, using multidimensional analysis and benchmarking efficient units. This work intends to call the academic community's attention to a technique able to assist the attaining of satisfactory results for this issue: the Data Envelopment Analysis, DEA, disseminating it as a technique to be used when conducting studies aiming at verifying the efficiency of units, through the proposal of a systematic to assist its implementation. Starting from a literature review that brings some light to aspects concerning the importance of establishing a set of performance indicators suitable for what, in fact, is in need of measurement, a brief summary of the main multicriteria techniques usually used for performance assessment is made, allowing more space for the discussion over the Analytic Hierarchy Process - AHP - and DEA. Specifically about DEA, focus of this dissertation, besides the traditional models that consider constant and variable returns to scale, respectively CCR and BCC, some extensions are also studied, allowing for weight restrictions, like in cone-ratio DEA, and the break of eventual matches registered among efficient units, like in cross-efficiency and super-efficiency DEA. Next, in the core of this work, a systematic for DEA implementation is structured, consisting on a sequence of steps to be followed in order to make the data envelopment analysis application feasible in distinct situations. The practical application of the suggested systematic is accomplished through the study of two cases. In the first one, with the objective of proposing a new way of assessing the performance of countries in their search for the sustainable growth, 76 nations are evaluated according to their social, economic and environmental perspectives, resulting in the proposal of a consolidated indicator: the National Sustainability Factor, or GSN. On the subsequent case, aiming at studying passenger transporting air companies, the objective is to identify those companies which are operationally more efficient according to their size, resulting in the identification of a certain influence of their geographic base location over the performance shown, although no evidence has been found that the affiliation to one of the major global alliances may also cause any kind of influence in the results. The applications conduced in this work evidence the potential for DEA to be used as a performance assessment tool under a multicriteria perspective in distinct sceneries.

Em um ambiente caracterizado pela elevação dos níveis de competitividade e surgimento de demandas mais complexas para a manutenção das instituições, cresce a consciência de que as abordagens convencionais para o tratamento da avaliação de desempenho não são mais suficientes. O cenário atual requer que se lance mão de ferramentas capazes de tratar essa questão com a devida atenção, utilizando, por exemplo, análises multidimensionais e referenciamento de unidades eficientes através do estabelecimento de benchmarkings. Este trabalho procura chamar a atenção da comunidade acadêmica para uma técnica capaz de auxiliar na obtenção de resultados satisfatórios para essa questão: a Análise Envoltória de Dados, ou DEA, disseminando-a como técnica a ser utilizada na realização de estudos que objetivem verificar a eficiência relativa das unidades sob análise através da proposição de uma sistemática de apoio à sua aplicação. Partindo-se de uma revisão que busca elucidar aspectos a respeito da importância de despenderem-se esforços com o estabelecimento de um conjunto de indicadores de desempenho adequado àquilo que, de fato, precisa ser medido, chega-se a um breve apanhado a respeito das principais técnicas de análise multicriterial utilizadas na avaliação de desempenho, com destaque para o Método de Análise Hierárquica - AHP - e a DEA. Especificamente quanto à DEA, foco deste trabalho, são abordadas, além dos modelos tradicionais que consideram retornos constantes e variáveis à escala de produção, respectivamente CCR e BCC, também algumas evoluções sobre os mesmos, considerando a atribuição de restrições aos pesos das variáveis, como no cone-ratio DEA, e a eliminação do eventual empate registrado entre unidades consideradas eficientes, caso do cross-efficiency e do super-efficiency DEA. Em seguida, procede-se à elaboração da sistemática para a utilização da DEA, núcleo deste trabalho, a qual consiste numa seqüência de passos a ser seguida com o intuito de viabilizar a aplicação da análise envoltória de dados em situações de naturezas distintas. A aplicação da sistemática se dá através do estudo de dois casos. No primeiro, tendo por objetivo sugerir uma nova forma de avaliar o desempenho dos países do globo tendo em vista o seu grau de sustentabilidade, 76 nações são avaliadas segundo as perspectivas social, econômica e ambiental, resultando na proposição de um indicador consolidado, o Grau de Sustentabilidade Nacional, ou GSN. No caso subseqüente, ao estudar-se as companhias de transporte aéreo de passageiros, objetiva-se identificar aquelas operacionalmente mais eficientes de acordo com seu porte de operação, resultando na identificação de uma certa influência quanto à origem geográfica das companhias sobre o desempenho apresentado, embora não se tenham identificado indícios de que afiliação a uma das grandes alianças globais também cause alguma influência no resultado. As aplicações conduzidas neste trabalho evidenciam a potencialidade de uso da DEA como ferramenta para a avaliação do desempenho sob uma perspectiva multicriterial em cenários distintos. / In an environment characterized by the raise in competitiveness levels and the emergence of more complex demands to deal with current issues, people get more conscious about the insufficiency of ordinary approaches for performance appraisal. The current scenery demands analysts to use a set of tools that are able to handle this issue with the required attention, for example, using multidimensional analysis and benchmarking efficient units. This work intends to call the academic community's attention to a technique able to assist the attaining of satisfactory results for this issue: the Data Envelopment Analysis, DEA, disseminating it as a technique to be used when conducting studies aiming at verifying the efficiency of units, through the proposal of a systematic to assist its implementation. Starting from a literature review that brings some light to aspects concerning the importance of establishing a set of performance indicators suitable for what, in fact, is in need of measurement, a brief summary of the main multicriteria techniques usually used for performance assessment is made, allowing more space for the discussion over the Analytic Hierarchy Process - AHP - and DEA. Specifically about DEA, focus of this dissertation, besides the traditional models that consider constant and variable returns to scale, respectively CCR and BCC, some extensions are also studied, allowing for weight restrictions, like in cone-ratio DEA, and the break of eventual matches registered among efficient units, like in cross-efficiency and super-efficiency DEA. Next, in the core of this work, a systematic for DEA implementation is structured, consisting on a sequence of steps to be followed in order to make the data envelopment analysis application feasible in distinct situations. The practical application of the suggested systematic is accomplished through the study of two cases. In the first one, with the objective of proposing a new way of assessing the performance of countries in their search for the sustainable growth, 76 nations are evaluated according to their social, economic and environmental perspectives, resulting in the proposal of a consolidated indicator: the National Sustainability Factor, or GSN. On the subsequent case, aiming at studying passenger transporting air companies, the objective is to identify those companies which are operationally more efficient according to their size, resulting in the identification of a certain influence of their geographic base location over the performance shown, although no evidence has been found that the affiliation to one of the major global alliances may also cause any kind of influence in the results. The applications conduced in this work evidence the potential for DEA to be used as a performance assessment tool under a multicriteria perspective in distinct sceneries.

Em um ambiente caracterizado pela elevação dos níveis de competitividade e surgimento de demandas mais complexas para a manutenção das instituições, cresce a consciência de que as abordagens convencionais para o tratamento da avaliação de desempenho não são mais suficientes. O cenário atual requer que se lance mão de ferramentas capazes de tratar essa questão com a devida atenção, utilizando, por exemplo, análises multidimensionais e referenciamento de unidades eficientes através do estabelecimento de benchmarkings. Este trabalho procura chamar a atenção da comunidade acadêmica para uma técnica capaz de auxiliar na obtenção de resultados satisfatórios para essa questão: a Análise Envoltória de Dados, ou DEA, disseminando-a como técnica a ser utilizada na realização de estudos que objetivem verificar a eficiência relativa das unidades sob análise através da proposição de uma sistemática de apoio à sua aplicação. Partindo-se de uma revisão que busca elucidar aspectos a respeito da importância de despenderem-se esforços com o estabelecimento de um conjunto de indicadores de desempenho adequado àquilo que, de fato, precisa ser medido, chega-se a um breve apanhado a respeito das principais técnicas de análise multicriterial utilizadas na avaliação de desempenho, com destaque para o Método de Análise Hierárquica - AHP - e a DEA. Especificamente quanto à DEA, foco deste trabalho, são abordadas, além dos modelos tradicionais que consideram retornos constantes e variáveis à escala de produção, respectivamente CCR e BCC, também algumas evoluções sobre os mesmos, considerando a atribuição de restrições aos pesos das variáveis, como no cone-ratio DEA, e a eliminação do eventual empate registrado entre unidades consideradas eficientes, caso do cross-efficiency e do super-efficiency DEA. Em seguida, procede-se à elaboração da sistemática para a utilização da DEA, núcleo deste trabalho, a qual consiste numa seqüência de passos a ser seguida com o intuito de viabilizar a aplicação da análise envoltória de dados em situações de naturezas distintas. A aplicação da sistemática se dá através do estudo de dois casos. No primeiro, tendo por objetivo sugerir uma nova forma de avaliar o desempenho dos países do globo tendo em vista o seu grau de sustentabilidade, 76 nações são avaliadas segundo as perspectivas social, econômica e ambiental, resultando na proposição de um indicador consolidado, o Grau de Sustentabilidade Nacional, ou GSN. No caso subseqüente, ao estudar-se as companhias de transporte aéreo de passageiros, objetiva-se identificar aquelas operacionalmente mais eficientes de acordo com seu porte de operação, resultando na identificação de uma certa influência quanto à origem geográfica das companhias sobre o desempenho apresentado, embora não se tenham identificado indícios de que afiliação a uma das grandes alianças globais também cause alguma influência no resultado. As aplicações conduzidas neste trabalho evidenciam a potencialidade de uso da DEA como ferramenta para a avaliação do desempenho sob uma perspectiva multicriterial em cenários distintos. / In an environment characterized by the raise in competitiveness levels and the emergence of more complex demands to deal with current issues, people get more conscious about the insufficiency of ordinary approaches for performance appraisal. The current scenery demands analysts to use a set of tools that are able to handle this issue with the required attention, for example, using multidimensional analysis and benchmarking efficient units. This work intends to call the academic community's attention to a technique able to assist the attaining of satisfactory results for this issue: the Data Envelopment Analysis, DEA, disseminating it as a technique to be used when conducting studies aiming at verifying the efficiency of units, through the proposal of a systematic to assist its implementation. Starting from a literature review that brings some light to aspects concerning the importance of establishing a set of performance indicators suitable for what, in fact, is in need of measurement, a brief summary of the main multicriteria techniques usually used for performance assessment is made, allowing more space for the discussion over the Analytic Hierarchy Process - AHP - and DEA. Specifically about DEA, focus of this dissertation, besides the traditional models that consider constant and variable returns to scale, respectively CCR and BCC, some extensions are also studied, allowing for weight restrictions, like in cone-ratio DEA, and the break of eventual matches registered among efficient units, like in cross-efficiency and super-efficiency DEA. Next, in the core of this work, a systematic for DEA implementation is structured, consisting on a sequence of steps to be followed in order to make the data envelopment analysis application feasible in distinct situations. The practical application of the suggested systematic is accomplished through the study of two cases. In the first one, with the objective of proposing a new way of assessing the performance of countries in their search for the sustainable growth, 76 nations are evaluated according to their social, economic and environmental perspectives, resulting in the proposal of a consolidated indicator: the National Sustainability Factor, or GSN. On the subsequent case, aiming at studying passenger transporting air companies, the objective is to identify those companies which are operationally more efficient according to their size, resulting in the identification of a certain influence of their geographic base location over the performance shown, although no evidence has been found that the affiliation to one of the major global alliances may also cause any kind of influence in the results. The applications conduced in this work evidence the potential for DEA to be used as a performance assessment tool under a multicriteria perspective in distinct sceneries.

O atual ambiente de alta competitividade do Mercado tem levado os produtores a operar com margens de lucro cada vez mais restritas. Nesse sentido, é imperativa a racionalização dos custos de produção, bem como a otimização dos processos produtivos. Diante de tal cenário, o controle preditivo baseado em modelos tem sido apresentado como uma poderosa alternativa para a obtenção dos objetivos acima mencionados. Sendo assim, é essencial que seja estabelecida uma metodologia de análise, baseada em critérios claros, acompanháveis e mensuráveis. Atualmente, encontram-se disponíveis no mercado distintas metodologias e suas respectivas ferramentas de suporte, as quais auxiliam na realização de tais análises. Quando se observa o número de soluções de controle avançado disponíveis, juntamente com as metodologias e ferramentas de análise de desempenho disponíveis, nota-se que existe um amplo espectro de possíveis combinações a ser avaliado. O objetivo desse trabalho é estudar algumas dessas combinações. São aqui avaliados o desempenho de controladores preditivos, à luz de algumas das consagradas técnicas de avaliação, bem como a própria efetividade e aplicabilidade de tais técnicas. São utilizados e analisados os seguintes controles avançados: Controlador Preditivo Generalizado (GPC); Controlador Multivariável Robusto; e Controlador ESSMPC. Para a avaliação de desempenho, serão utilizadas e estudadas as seguintes técnicas: Controller Performance Index (CPI); Cp e Cpk; e Índice de Yu e Qin. Os resultados mostraram que o Controlador Robusto Multivariável apresentou desempenho similar ao ESSMPC e ambos apresentaram desempenho melhor que o GPC. Todos os algoritmos apresentaram maior sensibilidade às mudanças nos pesos das variáveis controladas e menor nos pesos das manipuladas. No caso da inserção de erros, os algoritmos apresentam sensibilidade maior até 35% de erro. Após tal valor, a diferença de desempenho não é tão significativa. Além disso, o Cp, Cpk e Índice de Yu e Qin se comportaram de forma similar, mas diferentes do CPI. / The current environment of high competitiveness of the market has led producers to operate with profit margins increasingly restricted. Therefore, it is imperative to streamlining production costs, as well as the optimization of production processes. Faced with this scenario, the model predictive control has been presented as a powerful alternative for obtaining the objectives stated above. Therefore, it is essential to establish a methodology of analysis, based on clear and measurable criteria. Currently, there are different methods and support tools available in the Market which help in such analysis. These methodologies and tools may evaluate the problem only quantitatively (increased production of a particular unit, for example) or qualitatively (how close to the predictions of advanced control solution is the actual behavior of the plant, for example). When one observes the number of advanced control solutions available, along with methodologies and tools available for performance analysis, we note that there is a wide spectrum of possible combinations to be evaluated. The aim of this work is to study some of these combinations. It will be observed the performance of advanced control solutions, through some of the most famous evaluation techniques, as well as their own effectiveness and applicability of such techniques. For the execution of the work will be used and analyzed the following advanced control solutions: Generalized Predictive Controller (GPC); Robust Multivariable Controller; and Controller ESSMPC. For the performance assessment, it will be used and studied the following techniques: Controller Performance Index; Cp and Cpk; and Qin and Yu Index. The results showed that the Robust Multivariable Controller performance was similar to ESSMPC and both performed better than the GPC. All algorithms showed greater sensitivity to changes in the weights of the controlled variables than on weights for manipulated variables. In the case of error insertion, the algorithms exhibit greater sensitivity up to 35% of mismatch. After this value, the performance difference was not very significant. Moreover, the Cp index Cpk and Qin and Yu behaved similar but different than CPI.

Economic performance assessment (EPA) of control systems is receiving increasing attention in both academia and industry. It addresses the estimation of the potential benefits resulting from control upgrade projects and monitoring and improvement of economic performance of the control system. Economic performance of control systems can often be related to crucial controlled variables dynamically and when controlled variables move away from an optimal operating point either more profit will be made or more cost will be incurred. This relation can be modelled by performance functions (PFs). When the multivariate nature of a process’s economic model is not considered, PFs of different controlled variables are referred to as individual performance functions. Otherwise, PFs of dependent controlled variables are referred to as joint performance functions. PFs play an important role in the latest techniques of EPA. There appears, however, to be no systematic method for developing PFs. The lack of such a method restrains further research into EPA, as without well-established PFs an EPA cannot be conducted smoothly and therefore cannot effectively support decision-making for management. The development of PFs is a bottleneck in the further research into EPA. Furthermore, the multivariate nature of processes has not been taken into account sufficiently as far as the relevant literature is concerned, which hampers the accuracy of PFs and accordingly the accuracy of economic assessment results. The contributions of this thesis lie in the following aspects: • A methodology for developing PFs is proposed, based on the PF development for an electric arc furnace, a grinding mill circuit and a stage of a bleach plant. • A comprehensive case study of an EPA of three controllers of a grinding mill circuit is conducted using a newly published framework to show the significance of PFs and how to perform an EPA systematically. • The current practice and guidelines on the control and functional/economic performance assessment of grinding mill circuits are captured using a survey study. The multivariate nature of an electric arc furnace’s economic model is investigated and joint performance functions are built based on individual performance functions. A multivariate economic assessment is conducted that shows how joint performance functions can help to provide a more accurate estimate of the economic performance of a controlled process. A web-based survey study on grinding mill circuits in mineral processing industries is conducted. One of its objectives is to obtain general PFs of grinding circuits. The survey results provide instructive insight into the PFs of grinding circuits. Furthermore, an in-depth literature review is conducted and the relationship between the product’s particle size distribution of grinding mill circuits and mineral recovery in downstream flotation circuits is revealed. The PFs of a grinding mill circuit being considered are formed, based on the survey results and literature study. An investigation into the PF development of a stage of a bleach plant is performed and crucial ideas used for their development are abstracted. A methodology for developing PFs for the EPA of control systems is then proposed by synthesising the methods used in the PF development described above. This methodology mainly includes the following stages: Stage 1: Determine information required for PF development. • Process operation and control understanding. • Process economics understanding. Stage 2: Gain required information on PF development. • PF-related information elicitation using survey research. • PF-related information available in the literature, including textbooks, journal papers, conference papers. • PF-related information from plant tests. Stage 3: Obtain suitable performance measures. Stage 4: Make suitable assumptions. Stage 5: Determine PFs. Stage 6: Develop Joint PFs. An economic assessment of three controllers (a nonlinear model predictive controller, a decentralized controller and three single-loop proportional-integral-derivative controllers) of the considered grinding mill circuit is conducted, using an EPA framework published recently to show the central role of PFs in the EPA and how to perform an EPA systematically. The circuit’s PFs, developed as described above, are used for the assessment. The EPA also shows that the improvement in the economic performance with the nonlinear model predictive controller mainly results from the improvement of the operating point and the controlled variables’ variation reduction only contributes a small part to the overall improvement, due to the characteristic of the PF of the circuit’s product particle size distribution. In addition, a web-based survey study is conducted and the current practice and guidelines on the control and functional/economic performance assessment of grinding mill circuits are captured. The questionnaire used for the study includes five segments. The first part identifies the respondents and the second part is intended to obtain background information on the milling circuits. The third part concerns the choice of key process variables and their economic impact. Part four involves the control of milling circuits and control loop performance and part five covers economic issues. / Thesis (PhD)--University of Pretoria, 2010. / Electrical, Electronic and Computer Engineering / unrestricted

The Performance Management System (PMS) has been introduced in the Republic of South African public service with intentions of planning, monitoring, developing under-performance, rating and rewarding good performance. The study was undertaken as an attempt to investigate the impact of the PMS on employees of the ECPL. The literature review shows that there are challenges facing the institution with regards to implementation of PMS. The findings of the study indicated that the supervisors have no understanding of PMS instead they used it as punishing tool. Other findings of the study showed that there’s a culture within the institution of using PMS as a money making scheme or a 14th checque. To achieve this, a semi- structured questionnaire was issued to employees of the ECPL. The recommendation on the basis of the study is that the compliance issue should be strengthened and disciplinary measures be taken against employees who failed to comply with the provisions of the PMS policy.

This article details the experiences of four teacher education faculty members as we navigated the consequential implementation of a state-mandated high stakes teacher performance assessment in our educator preparation program. By shifting our perspective from simply complying with an assessment mandate to considering how we can leverage implementation of high stakes performance assessment as a vehicle for program inquiry, we were able to gain significant insight into our practice.

The vocal performance database is a tool by which BYU vocal performance faculty and students may practice, assess, and review vocal performances, including practice juries, recitals, and end-of-semester juries. This document describes the process and results of designing, developing, implementing, and evaluating the vocal performance database. By using this tool, vocal performance professors are able to give faster, more quality feedback to students following the jury. Students are able to receive legible feedback from their professors in a timely manner.

Yes / The performance of a batch reverse osmosis (RO) desalination process in terms of permeate quantity and salinity as a function of feed pressure and feed salinity is evaluated by using laboratory experiments and process modelling. Special attention is paid to the water and salt permeability constants (Kw, Ks) which affect the permeate and salt flux across the membrane. Kw and Ks are found to be strongly pressure-dependent for the batch system which is in-line with earlier observations for continuous RO systems. However, the most important findings of this work are the dependence of Kw and Ks on feed salinity, something that have never been observed or reported in the literature. In order to better qualify these observations, further experiments with the batch system are conducted with a constant feed salinity so that the operating condition resembles that of a continuous RO process.