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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
271

Implementation and Tuning of PID, Fractional PID and LA Controllers for pH Control

Ardinugroho, Servatius Bismanditio 25 January 2019 (has links)
Maintaining the pH of a fluid or a solution at a specific value is a concern in many industrial processes, wastewater management, and food and pharmaceutical production. Given the importance of controlling pH in many processes, the objective of this thesis is to study and compare the effectiveness of some controller algorithms to control the pH of a process. In this study, the performance of three controller algorithms, namely PID, fractional PID and LA controllers, is evaluated for the control of a simple neutralization process using conventional controller performance metrics. Performance metrics used are the response time, the Integral of the Time weighted Absolute Error (ITAE), the Integral of the Squared Error (ISE), and the Integral of the Squares of the changes (ΔU) in the manipulated variable (ISDU). The three controllers were therefore tuned to minimize one or a combination of the controller performance metrics. Results show that PID, fractional PID and LA controllers implemented and tested in this research are all worthy controllers for maintaining pH of the neutralization process. Simulation results show that the three controllers can be used with confidence to cope with the high nonlinearity of a pH neutralization process provided that the process is properly designed. The relative small gain in performance obtained with the fractional PID controller, compared to a linear PID controller, suggests that it is not worth resorting to a fractional PID controller given its complexity and higher computation effort. Results show that PID and LA controllers are easy to implement with short response time and low ITAE and ISDU performance metrics.
272

Avaliação de padrões para implementação de modelos de dados orientados a objetos em bancos de dados relacionais. / Patterns evaluation for implementation of object-oriented data models into relational databases.

Rizzo, July Any Martinez de 11 November 2010 (has links)
A questão da implementação de modelos de dados que utilizam a orientação a objetos constitui-se, ainda, em um assunto não totalmente consolidado. Dessa forma, nesta dissertação realiza-se uma sistematização relativa à implementação de um banco de dados relacional representado por um diagrama de classes. Este trabalho apresenta como foco principal uma avaliação de métricas do mapeamento de três tipos de relacionamento de um modelo orientado a objetos, Herança, Agregação/Composição e Associação, quando aplicados a um modelo relacional de banco de dados. Para isso, foram avaliados ao todo sete padrões de mapeamento desses relacionamentos para a modelagem relacional, sendo dois padrões de Herança, dois de Agregação e dois de Associação, além de análise de estudos empíricos relacionados ao tema. Ambas as formas de modelagem, relacional e orientada a objetos, são compatíveis quando analisadas suas modelagens conceituais. Assim, avalia-se a adequação da implementação dos modelos orientados a objetos em um banco de dados relacional após a aplicação dos padrões de mapeamento. Como resultado deste trabalho, é apresentada uma proposta de análise de métricas da aplicação dos padrões de mapeamento em um modelo apropriado para implementação em um banco de dados relacional. Algumas das métricas avaliadas são desnormalização, método de armazenamento lógico alinhado à estratégia de indexação, alta disponibilidade e uso de métodos de replicação, custo de acesso a dados, espaço em disco e flexibilidade e custo de manutenção. / Implementation of object-oriented data models constitutes in a not fully consolidated subject yet. Thus, this work performs an evaluation about a relational database implementation represented by a class diagram. The main focus of this paper is to present a systematic metric evaluation for the mapping of three relationships types of an object-oriented model, Inheritance, Aggregation / Composition and Association, when applied to a relational database model. For this purpose, seven mapping patterns that transform these relationships into a relational model notation were evaluated, two patterns of Inheritance, two of Aggregation, and two of Association, besides the analysis of empirical studies related to the topic. Both forms of modeling, relational and object-oriented, are considered compatible when their conceptual modeling is analyzed. So this paper evaluates the adequation of the object-oriented models implementation in a relational database after the appliance of the mapping standards. As a result of this work, it is presented an analysis of metrics proposal from the mapping patterns application in a suitable model for implementation in a relational database. Some of the evaluated metrics are denormalization, logical storage method aligned to indexing strategy, high availability and use of replication methods, cost of access to data, disk space and flexibility and maintenance costs.
273

Avaliação do desempenho de busca de imagens por conteúdo em redes de computadores: uma proposta de reengenharia com aplicação a imagens médicas / Performance evaluation of images by content search in computer networking

Oliveira, Fabio Brussolo de 27 February 2012 (has links)
O objetivo deste trabalho é avaliar a recuperação de imagem por conteúdo (CBIR - Content-based Image Retrieval) em uma rede de computadores, estabelecendo-se métricas de controle que otimizem a utilização da rede e ao mesmo tempo garanta melhor qualidade na resposta. Prevê-se a recuperação de imagens baseada em consulta por similaridade, combinando-se o extrator de características com a função de distância. O desenvolvimento é realizado em uma linguagem de programação independente da plataforma e de âmbito de internet, utilizado Java, desenvolvendo-se uma API (Application Programming Interface), visando, em especial, a reutilização de código, o que implica na diminuição do tempo de desenvolvimento. O trabalho demonstra a utilização de estruturas de indexação sequencial, comparada com a estrutura de indexação de árvore \"Slim-tree\". A principal contribuição deste trabalho é a análise e a utilização de métricas na rede de computadores em um projeto de CBIR. / The objective of this study is to evaluate the Content-based Image Retrieval (CBIR) in a computer network, establishing control metrics that optimize the use of network while ensuring better quality in the response. It is expected that images are going to be recovered based on queries that are similar, combining the features extractor with the distance function. The development environment is an independent language of the platform and of the Internet scope, using Java, that has developed an Application Programming Interfaces (API), aiming primarily the code reuse, which implies a decrease in the development time. This thesis demonstrates the use of sequential indexing structures compared to the tree index structure \"Slim-tree\". The main contribution of this thesis is the analysis and utilization of metrics in a computer network project in CBIR.
274

Uso de invertebrados bentônicos na avaliação da qualidade da água da bacia do Alto Atibaia (SP) / Use of benthic invertebrate in water quality assessment of Atibaia river basin (São Paulo, State)

Fidalgo, Vanessa Hermida 05 February 2007 (has links)
Devido à importância do uso de bioindicadores para avaliação da qualidade ambiental e às vantagens do emprego de macroinvertebrados bentônicos para este fim, estes organismos foram utilizados para avaliar a qualidade da água da bacia do alto Atibaia (SP) em oito pontos de amostragem: 3 no rio Atibainha, 3 no rio Cachoeira e 2 no rio Atibaia. Foram amostrados o canal, a margem deposicional e a margem erosional, sendo coletadas três unidades amostrais em cada ambiente de cada ponto, com auxílio do amostrador Hess (rede de 500 μm e área de 678,9 cm2) ou pegador Petersen modificado (área de pegada de 325 cm2). Foram coletadas amostras de sedimento com pegador Petersen modificado em aço inox para análise de granulometria, resíduos totais, voláteis e fixos e umidade. Este trabalho está dividido em três capítulos. No primeiro, a análise da fauna evidenciou que os pontos de cabeceira e à jusante dos reservatórios dos rios Atibainha e Cachoeira tenderam a apresentar riqueza e diversidade menores que os pontos de localização intermediária. Já nos pontos situados no rio Atibaia, a fauna respondeu à deterioração da qualidade da água, refletindo um gradiente ambiental. No segundo capítulo, visando à utilização de técnicas de avaliação rápida para facilitar a análise e interpretação de dados, foram aplicadas vinte e uma métricas biológicas. Dentre todas as métricas testadas, as que evidenciaram o gradiente ambiental presente na bacia estudada, com restrito coeficiente de variação no ponto referência foram riqueza e diversidade de famílias, densidade total, riqueza de EPT e ETO, porcentagem de Táxons de Diptera (exceto Tanytarsini) e não insetos, BMWP “JUNQ" e IBBJ. No terceiro capítulo, com a finalidade de contribuir para a elaboração de um plano de monitoramento de avaliação rápida para a bacia do Alto Atibaia (SP), concluiu-se que, com a metodologia empregada, a margem erosional seria o habitat que melhor corresponderia à media ou somatória para o ponto, pelo menos durante o período de estiagem. / Due to importance of the use of bioindicators to assess environmental quality and the advantages of employing benthic macroinvertebrates for this purpose, these organisms were used to assess the water quality of the Atibaia river basin (SP) in eight sites: 3 in the Atibainha river, 3 in the Cachoeira river, and 2 in the Atibaia river. Channel, depositional margin and erosional margin were sampled. Three replicates were collected in each habitat using a Hess sampler (678.9 cm2, 500μm mesh) or modified Petersen grab (325 cm2). Sediment samples were collected with a stainless steel modified Petersen grab for analysis of granulometry, humidity and total, volatile and fixed residues. This study is divided in three chapters. In the first, the fauna showed that headwater and downstream reservoir sites of Cachoeira and Atibainha rivers presented lower richness and diversity than intermediate sites. In the sampling sites of the Atibaia river, the fauna responded to the water quality decline, reflecting an environmental gradient. In the second chapter, aiming the utilization of rapid assessment techniques to facility data analysis and interpretation, twenty one biological metrics were applied. Metrics that evidence the environmental gradient of the basin, with restricted variation coefficient, were richness and diversity of families, total density, richness of EPT and ETO, percent of Diptera taxa and noninsects, BMWP “JUNQ" and IBBJ. In the third chapter, aiming to contribute to the development of a rapid assessment monitoring plan for the Atibaia river basin, according to the methodology employed, it was concluded that the erosional margin was the habitat that showed the best correspondence with the average or sum of the sites, at least during the dry season.
275

Making Sense of Journal Rankings in Mathematics Education

Nivens, Ryan Andrew, Otten, Samuel 01 November 2015 (has links)
What are the top journals in the field of mathematics education? This presentation will examine how quality of academic journals can be assessed and how to determine what journal metrics, if any, are of concern to scholars in the field.
276

Assessing Journal Quality in Mathematics Education

Nivens, Ryan Andrew, Otten, Samuel 02 February 2017 (has links)
No description available.
277

Making Sense of Journal Rankings in Mathematics Education

Nivens, Ryan Andrew 28 January 2016 (has links)
What are the top journals in the field of mathematics education? This presentation will examine how quality of academic journals can be assessed and how to determine what journal metrics, if any, are of concern to scholars in the field.
278

Assessing Journal Quality in Mathematics Education

Otten, Samuel, Nivens, Ryan Andrew 26 July 2017 (has links)
Excerpt: In this study, we triangulate the rankings in Table 1 with other measures of journal quality offered through database algorithms.
279

A Metrics Love Story: The Dance Between a State and TF-CBT Adoption

Ebert, Jon, Moser, Michele R., Todd, Janet 01 March 2011 (has links)
No description available.
280

Seasonal Round Travel Routes and the Cost of Mobility

Mills, Evan 01 June 2018 (has links)
In 1985 a settlement and subsistence model of seasonal round mobility was proposed by Statistical Research, Inc. This model proposed four travel routes used by the Late Prehistoric Serrano to access the higher elevation village site known as Rock Camp to gather acorns and pinyon nuts in the fall. This research investigates the proposed routes, as well as an additional route, for energy efficiency and archaeological evidence of use in prehistory. Data collection involved using experimental methods designed to gather controlled physiological data for evaluating the efficiency of traveling each route. Archaeological sites present on the travel routes and within the research area and were analyzed for elements indicative of prehistoric settlement characteristics. A combination of physiological evidence and archaeological evidence are the basis for determinations on which routes were most likely to have been used in prehistory. An analysis of the settlement model is also provided in order to provide future research with guidelines and context for evaluating sites within the region. Suggestions are provided for future studies to focus on chronology and expansion of the settlement model.

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