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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.
151

A influ?ncia da adi??o de caulim, quartzo e feldspato pot?ssico na formula??o de massas cer?micas para telhas: Modelo estat?stico

Ara?jo, Janiara Ferreira de 13 November 2008 (has links)
Made available in DSpace on 2014-12-17T14:57:49Z (GMT). No. of bitstreams: 1 JaniaraFA.pdf: 946913 bytes, checksum: 7a2683c43f2b9a59eaca617cf3e52563 (MD5) Previous issue date: 2008-11-13 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The production of roof tiles in the state of Rio Grande do Norte accounts for around 60% of the total of ceramic pieces produced. There is a need for investment to improve quality and productivity, thereby promoting technological innovations. Accordingly, the aim of this study is to determine the effect of kaolin, potassium feldspar and quartz in two standard formulations, as well as the effect of sintering temperature on the technological properties of linear firing shrinkage, water absorption and bending rupture stress, by fitting the statistical model and using multiple linear regression to assess the relationship between technological properties and independent variables. The raw materials were characterized using the following techniques: X-ray fluorescence (XRF), X-ray diffraction (XRF), rational analysis (RA), differential thermal analysis (DTA) and granulometric analysis (GA). The test specimens were compacted by uniaxial pressure (25 MPa), dried in a stove at 110 ?C for 24 hours and sinterized at 850 ?C, 950 ?C and 1050 ?C and held isothermal for 30 minutes. The results obtained indicate that the addition of kaolin to two standard formulations (M and R) promoted a reduction in water absorption values and an increase in bending rupture stress values. The sintering temperatures for group M that resulted in the lowest linear firing shrinkage and water absorption values were 850 ?C and 950 ?C, respectively, and the highest bending rupture stress values were reached at a temperature of 950 ?C. In the case of group R, the sintering temperature that obtained the lowest water absorption and linear firing shrinkage values was 850 ?C, and the highest bending rupture stress values were attained at a temperature of 1050 ?C. This work explains the statistical approach used to fit the model that describes the relationship between the technological properties and percentage of kaolin, quartz and feldspar, as well as the models that enable predictions, provided that the lower and upper limits of the percentage of clay minerals, flux and quartz used in this study are respected. Statistica 6 software was used and results were obtained by stepwise forward regression / A produ??o de telha no Estado do Rio Grande do Norte representa cerca de 60 % do total de pe?as cer?micas produzidas. Percebe-se a necessidade de investimento na melhoria da qualidade e da produtividade, promovendo assim inova??es tecnol?gicas. Neste contexto, o objetivo geral deste trabalho ? verificar o efeito da adi??o de caulim, feldspato pot?ssico e quartzo em duas formula??es padr?o, assim como o efeito da temperatura de sinteriza??o nas propriedades tecnol?gicas de retra??o linear de queima, absor??o de ?gua e tens?o de ruptura ? flex?o, atrav?s do ajuste do modelo estat?stico, sendo utilizada a regress?o linear m?ltipla para avaliar a rela??o entre as propriedades tecnol?gicas e as vari?veis independentes. As mat?rias-primas foram caracterizadas atrav?s das seguintes t?cnicas: fluoresc?ncia de raios X (FRX), difra??o de raios X (DRX), an?lise racional (AR), an?lise t?rmica diferencial (DTA) e an?lise granulom?trica (AG). Os corpos-de-prova foram compactados por prensagem uniaxial (25 MPa), e na sequ?ncia secos em estufa a 110 ?C por 24 horas, em seguida sinterizados a 850 ?C, 950 ?C e 1050 ?C, com isoterma de 30 minutos. Os resultadosobtidos indicaram que a adi??o de caulim, em duas formula??es padr?o (M e R) promoveu redu??o nos valores de absor??o de ?gua e aumento nos valores de tens?o de ruptura ? flex?o. As temperaturas de sinteriza??o para o grupo M que proporcionaram os menores valores para a retra??o linear de queima e absor??o de ?gua foram 850 ?C e 950 ?C, respectivamente, e os maiores valores para a tens?o de ruptura ? flex?o foram alcan?ados na temperatura de 950 ?C. No caso do grupo R a temperatura de sinteriza??o que proporcionou os menores valores para absor??o de ?gua e retra??o linear de queima, foi a de 850 ?C, e os maiores valores para a tens?o de ruptura ? flex?o foram atingidosna temperatura de 1050 ?C. Este trabalho descreve a abordagem estat?stica para ajustar o modelo de regress?o linear m?ltipla e apresenta o ajuste do modelo que descreve a rela??o entre as propriedades tecnol?gicas e a porcentagem de caulim, quartzo e feldspato, assim como os modelos que possibilitam a realiza??o de predi??es, desde que n?o sejam ultrapassados os limites inferiores e superiores da porcentagem de argilominerais, fundente e quartzo utilizados neste trabalho. Para isto utilizou-se o software Statistica vers?o 6, obtendo resultados atrav?s da regress?o stepwise forward
152

Redovisningens värderelevans innan och efter införandet av IFRS 13 : En kvantitativ undersökning inom skogsindustrin

Helander, Agnes, Selin, Elin January 2018 (has links)
Värdering till verkligt värde har varit omdiskuterat sedan det infördes år 2005. Redovisningsstandarden IAS 41 tvingade jordbruksföretag, såsom företag inom skogsindustrin, att värdera deras biologiska tillgångar till verkligt värde. Tidigare studier har visat att detta i sin tur gav effekt på redovisningens värderelevans. För att informationen ska vara värderelevant ska ett samband finnas mellan aktiepris och det redovisade värdet. IFRS 13 infördes för att komplettera IAS 41 och ge en mer enhetlig syn om vad verkligt värde är, hur värderingen ska göras samt utökade upplysningskraven. Skulle denna kompletterande standard IFRS 13 öka redovisningens värderelevans för skogsindustrin? Detta undersöktes genom en totalundersökning på svenska och finska börsnoterade bolag inom skogsindustrin. Sambandet studerades genom korrelation- och regressionsanalyser. Variablerna som undersöktes var aktiepris, eget kapital per aktie och resultat per aktie. Förklaringsgraden visade att eget kapital per aktie och resultat per aktie inte kan förklara variansen i aktiepriset mer efter införandet; IFRS 13 gav inte någon ökad värderelevans för variablerna tillsammans. Däremot visade det sig att variabeln resultat per aktie enskilt gav en ökad värderelevans vilket tyder på att investerare bryr sig mer om resultaträkningen än balansräkningen. / Fair value has been discussed since its introduction in accounting in 2005. The accounting standard IAS 41 forced the companies in agriculture, such as forest industry companies, to value their biological assets at fair value. Earlier studies have shown that this increased the value relevance. In order for the information to be value relevant the accounting amount should have an association with the stock price. IFRS 13 was introduced to complement IAS 41 and provide a more unitary consensus on what fair value is. It also provides a guide on how the value is determined and additional disclosures requirements. Should this supplementary standard IFRS 13 increase the value relevance of the accounting for the forest industry? This was investigated through a study of listed companies in the forest industry located in Sweden and Finland. The relationship was studied through correlation and regression analyzes, where the variables share price, equity per share and earnings per share were examined. The explanatory power showed that equity per share and earnings per share were not able to explain share price at a higher level after the introduction; IFRS 13 did not increase value relevance for all the variables together. On the other hand, it was found that the variable earnings per share individually gave an increase in value relevance, which imply that investors care more about the income statement than the balance sheet.
153

Perpetual Peace through Democratic Aid? : Does Democratic Aid Significantly Contribute to Democratic Development among Semi-Democratic States?

Olsson, David January 2009 (has links)
The first purpose of this study is to examine if democratic aid is a statistically and/or substantially significant determinant of democratic development among semi-democratic states. The second purpose is to discuss the effects of democratic aid in light of the theory of ‘democratic peace’, and the debate on whether exogenous or endogenous factors are primary for democratic development. The research question is: how much, if at all, has democratic aid contributed to democratic development among semi-democratic states from 2000 to 2004? The thesis is delimited to observing the total population of states that were semi-democratic in the year 1999, i.e. 56 countries. Moreover, it only detects the potential impact of democratic aid over one five-year period, namely 2000-2004. Data from the Freedom House Index (FHI) has been used to distinguish states with semi-democratic regimes from states with other regime-types, and, moreover, to construct two indicators of the dependent variable. The utilized dataset on democratic aid is provided by the Creditor Reporting System (CRS), issued by the Organization for Economic Co-operation and Development (OECD). Furthermore, in order to assess the effects of democratic aid, a multiple regression model is employed that controls for nine other variables which have been found to have significant impacts on democratic development in relevant previous research. The conclusion is that democratic aid neither had a statistically nor a substantially significant impact on democratic development of semi-democratic states from 2000 to 2004. Thus, it does not strengthen the ‘exogenous standpoint’ for democratic development, and it does not appear to contribute to an expansion of ‘democratic peace’. However, due to a number of factors, it is acknowledged that more research is required in order to assess the effects of democratic aid more adequately.
154

Medierepresentationen av världens länder : Strukturer i fyra svenska nyhetstidningar

Bjurström, Peter January 2009 (has links)
This essay casts light on the quantitative aspect of the media representation of foreign news. The purpose of the essay is not only to describe the media representation of the countries of the world, but also to explain the representation out of structures that are mirrored by the mass media. Four hypotheses are stated that are operationalized in the research. These are treating four different factors that are believed to affect the representation, economy, geographical distance, cultural distance and the size of the population. A fifth hypothesis is stating that economy is the most influential of the factors. The factors are tested by using multiple regression analyses. Four Swedish newspapers have been selected for the study, two morning papers, one evening paper and one free daily newspaper. The representation is measured by the number of articles retrieved by searching a database containing the four newspapers. The search have included 183 countries and all articles from 2007 for these countries. The results shows that economy, geographical distance and size of population are the most important factors for the media representation. Economy is evinced to be the most influential of the factors.
155

Influência dos padrões estruturais da paisagem na comunidade de mamíferos terrestres de médio e grande porte na Região do Vale do Ribeira, Estado de São Paulo / The influence of the landscape structure pattern in assemblages communities of medium and large terrestrial mammals in the Vale do Ribeira Region - SP

Conrado Martignoni Spinola 18 June 2008 (has links)
Os estudos estabelecendo relações entre os dados biológicos e padrões espaciais têm contribuído para o entendimento de fenômenos ecológicos em escalas regionais e locais, mesmo que, ainda pouco se saiba sobre esses fenômenos. O enfoque dado a este estudo está voltado a uma interpretação da paisagem, no âmbito ecológico, de forma a entender o comportamento das espécies em relação a sua estrutura. A paisagem deste estudo é composta por diversos elementos, naturais e antrópicos, tais como as plantações de eucalipto e Florestas Estacionais Semideciduais, sendo um fator determinante na composição e distribuição espacial das espécies que a compõem. O objetivo principal deste estudo foi avaliar as relações estruturais da paisagem e o comportamento das espécies que compõem a comunidade de mamíferos terrestres de médio e grande porte na região do Vale do Ribeira, Estado de São Paulo. Essas espécies foram avaliadas a partir de levantamentos sistemáticos pelo método de amostragem \"parcelas de areia\", e a estrutura da paisagem caracterizada através das técnicas de geoprocessamento. Fez-se, ainda, a partir do centro de cada linha de amostragem, uma delimitação da paisagem com 1000 metros de raio, denominada área de influência. A partir das observações de campo constatou-se uma grande riqueza de espécies, totalizando 19 espécies. Destas, 17 espécies foram encontradas em ambiente de Florestas Estacionais Semideciduais e 11 espécies em ambiente de eucalipto, verificando-se certa similaridade de ocorrência para as espécies entre os ambientes amostrados. Através da análise da estrutura, por meio das métricas de paisagem (PLAND_NAT - porcentagem de vegetação nativa nas paisagens analisadas, PLAND_EUC - porcentagem de eucalipto nas paisagens analisadas, PLAND_EST - porcentagem de estradas nas paisagens analisadas, ED_NAT - densidade de borda de vegetação nativa, ENN_NAT - distância do fragmento mais próximo das paisagens analisadas), fez-se a caracterização das zonas de influência. Uma vez obtidas as informações acerca dos dados biológicos e dados da paisagem, realizaram-se as análises de regressão logística múltipla, onde foi verificado o poder de predição das variáveis ambientais em relação a algumas espécies da comunidade estudada. Individualmente, nenhuma variável ambiental pôde explicar a probabilidade de ocorrência das espécies, sendo que, quando utilizadas em conjunto, o poder de predição foi significativo para Leopardus sp. (gato-do-mato) Didelphis albiventris (gambá-de-orelha-branca), Nasua nasua (coati) e Sylvilagus brasiliensis (tapiti). Cada espécie percebe a paisagem de maneira diferente, que de acordo com os parâmetros estimados pelos modelos, Leopardus sp. e Didelphis albiventris apresentaram tendências positivas ao poder de explicação das variáveis PLAND_NAT e ENN_NAT, enquanto que, Nasua nasua uma tendência positiva para todas as variáveis e Sylvilagus brasiliensis uma tendência positiva a PLAND_EST e ENN_NAT. Embasar-se em modelos de predição para espécieschaves, seja em ambientes naturais ou antropizados, é bastante recomendado, pois a conservação de outras espécies pode estar diretamente vinculada. Para tanto, estudos de conservação enfocando comunidades e não apenas populações são interessantes, uma vez que podem abranger diferentes espécies com diferentes requerimentos. A configuração da paisagem, a partir das zonas de influência, pode ser uma amostra representativa da paisagem como um todo, auxiliando nas ações de conservação das espécies de maiores requerimentos ecológicos. / Studies establishing relationships among biological data and spatial patterns have contributed to the understanding of ecological phenomena at regional and local scales, even that, little is known about these phenomena. The approach adopetd in this study is focused to an ecological interpretation of the landscape, in order to understand the behavior of the species in relation to its structure. The studied landscape is composed of several natural and anthropic elements, such as Eucalyptus plantations and Seasonal Semideciduous Forests, being a determining factor in the composition and spatial distribution of the species in the landscape. The main objective of this study was to evaluate the structural relationship of the landscape and the behavior of species that compose the community of medium and large terrestrial mammals, in the Vale do Ribeira region, State of São Paulo, Brazil. These species were evaluated through systematic surveys, known as \"sand plots\", and the landscape structure was characterized by geoprocessing techniques. Yet, from the center of each sampling row, a delimitation of the landscape was done, with 1000 meters in radius, denominated influence zones. From field observations, a great richness of species was verified, totaling 19 species. From these, 17 species were found in Seasonal Semideciduous Forests landscape and 11 species in Eucalyptus landscape, which made it possible to verify some similarity in the species occurrence among the sampled environments. Through structure analysis, using landscape metrics (PLAND_NAT - percentage of native vegetation in the analyzed landscape, PLAND_EUC - percentage of Eucalyptus in the analyzed landscape, PLAND_EST - percentage of roads in the analyzed landscape, ED_NAT - edge density in the native vegetation, ENN_NAT - distance from analyzed landscapes to the nearest native vegetation fragment), the characterization of influence zones was made. Once obtained the information concerning the biological data and landscape data, a multiple logistic regression analyses was performed, when it was verified the prediction power of the environmental variables in relation to some species of the studied community. Individually, no environmental variable could explain the probability of species occurrence, but when used together, the prediction power was significant for Leopardus sp., Didelphis albiventris (opossum), Nasua nasua (coati) and Sylvilagus brasiliensis (tapiti). Using prediction models for key-species, whether in natural or anthropic environments, is highly recommended, as the conservation of other species can be directly linked. Therefore, studies on conservation focusing on communities and not only in populations are interesting, because they may cover different species with different requirements. The configuration of the landscape, taken from the influence zones, can be a representative sample of the landscape as a whole, helping in the actions for the conservation of the species with greatest ecological requirements.
156

O mercado imobiliário residencial da região metropolitana de São Paulo: uma aplicação de modelos de comercialização hedônica de regressão e correlação canônica / The Real Estate Market of Metropolitan Region of Sao Paulo: an hedonic models application of multiple regression and canonical correlation

Luiz Paulo Lopes Favero 29 September 2005 (has links)
Este trabalho destina-se a realizar um estudo sobre o mercado imobiliário de lançamentos residenciais da Região Metropolitana de São Paulo, tendo como base a utilização de modelos de comercialização hedônica. Para tanto, utiliza-se da Teoria dos Atributos proposta por Lancaster e dos modelos hedônicos e de equilíbrio de sub-mercados propostos por Rosen e Palmquist, a partir dos quais é possível analisar a importância relativa de “pacotes” de atributos, em função dos diferentes perfis sócio-demográficos determinados previamente por meio de análise fatorial elaborada com um grupo de 11 variáveis sócio-demográficas de cada Município da Região Metropolitana e de cada distrito do Município de São Paulo. Por meio de um levantamento realizado com especialistas, com compradores de imóveis residenciais e por meio de anúncios específicos, definiram-se as variáveis hedônicas explicativas e dependentes a serem incluídas nos modelos de regressão múltipla de Box-Cox e de correlação canônica, sob a ótica da demanda e da oferta, para cada perfil sócio-demográfico definido. O método proposto permite a determinação e a avaliação dos “pacotes” representativos de atributos para a composição das condições comerciais dos imóveis residenciais em lançamento na Região Metropolitana de São Paulo, propiciando a verificação da existência de eventuais descolamentos entre o comportamento da demanda e da oferta e possibilitando a comparação da importância relativa de cada variável entre os perfis sócio-demográficos. Portanto, a aplicação do método proposto neste trabalho pode propiciar a implementação de iniciativas privadas e políticas públicas voltadas ao estabelecimento de novas estratégias de lançamento imobiliário, designadas para cada tipo específico de empreendimento e de acordo com as preferências dos consumidores e das características de cada localidade. / This work intends to research about the residential launchings of the real estate market in the Metropolitan Region of Sao Paulo, using hedonic models. It’s based on the approach to Theory of Attributes, proposed by Lancaster, and on the hedonic models and the sub-markets equilibrium approach proposed by Rosen and Palmquist, that make possible the analysis of the relative importance of the attributes “bundles” for each different social and demographic group previously defined by the factorial analysis statistical technique, that used 11 social and demographic variables related to each Municipality of the Metropolitan Region of Sao Paulo and each district of the City of Sao Paulo. Using a survey realized with specialists, residential launchings buyers and through specific advertisements, many explicative and dependent hedonic variables were defined and are to be included in the models of Box-Cox multiple regression and canonical correlation, under the perspective of demand and supply, for each social and demographic defined group. The proposed method allows the determination and the evaluation of the representative “bundles” of attributes to the composition of the residential launchings commercial conditions of the Metropolitan Region of Sao Paulo real estate market, making possible to verify the existence of eventual gaps between the demand and supply behaviors and allowing the comparison of the relative importance of each variable among the social and demographic groups. Thus, the method application can facilitate private and public implementations, allowing the establishment of new strategies designated to each specific kind of real estate, according to the consumers’ preferences and local characteristics.
157

Geoestatística no estudo da variabilidade espacial de atributos químicos e físicos do solo e da produtividade da pimenta-do-reino / Geostatistics in the study of the spatial variability of chemical and physical attributes of soil and productivity of the Piper nigrum L.

Quartezani, Waylson Zancanella 29 February 2008 (has links)
Made available in DSpace on 2016-12-23T14:37:36Z (GMT). No. of bitstreams: 1 WAYLSON ZANCANELA QUARTEZANI.pdf: 1546721 bytes, checksum: ccf128143c8f389a26cd268610ba6253 (MD5) Previous issue date: 2008-02-29 / The culture of Piper nigrum L. is one of the most profitable crops in the north of the Espírito Santo State. In view of the actual situation of nutritional management of culture adopted in the State, allied to the cultivation in regions of low natural fertility and to the high nutritional requirement, new technologies have been aggregated to the production system in use, in order to be available to the productive segment. Based on that, the work had as main objective the use of geostatistics for the study of spatial variability of physical and chemical attributes of the soil and its effects on productivity of the crop. The work was carried out in an experimental area located in commercial farming of Piper nigrum L. in the District of Nestor Gomes, Highway ES 381 km 28, in the Municipality of São Mateus, north of the Espírito Santo State. In the collection of data a regular grid of approximately 1.5 ha was used, totaling 94 sampling points, spaced 18 x 12 m between them. To determine the attributes, the soil was collected in the projection of the canopy`s in the depth of 0 to 0.2 m. The productivity (kg plant-1) was assessed through two harvests, in a year. For the evaluations, initially, was made a descriptive exploratory analysis without taking into consideration the spatial position of the samples for the identification of measures of position, dispersion and discrepant points (outliers) and, after, an exploratory spatial analysis taking into consideration the position of samples in the area to identify possible tendencies. The analysis of the spatial variability of attributes studied was determined by standardized semivariograms. With the adjustment and choosing of the models were defined the parameters required for the estimation of the values in positions not sampled in the field using the interpolation method for ordinary kriging for the preparation of maps which allowed the distinction of regions with less and greater variability of the attributes evaluated. With the results we can conclude that the use of techniques of geostatistics allow the identification of areas of the differentiated management of soil fertility through of the mapping of attributes studied. All attributes present structure of spatial dependence with varying the degree of dependence between strong and moderate, except for the levels of P and Mg showing pure nugget effect and AG adjusted to the linear model. A multiple linear regression identified the K, Ca and Mg, respectively, as the chemical attributes of greater influence in determining the productivity, and the map of the productivity of Piper nigrum L. predicted by the multiple spatial regression show similar spatial behavior to the map of productivity of the crop estimated by kriging. / A cultura da pimenta-do-reino é um dos cultivos mais rentáveis na Região Norte do Estado do Espírito Santo. Tendo em vista a situação atual do manejo nutricional da cultura adotado no Estado, aliada ao seu cultivo em regiões de baixa fertilidade natural e a sua elevada exigência nutricional, novas tecnologias vêm sendo agregadas ao sistema de produção em uso, para serem disponibilizadas ao setor produtivo. Baseado nisso, o presente trabalho teve como objetivo principal o uso da geoestatística para o estudo da variabilidade espacial dos atributos físicos e químicos do solo e suas influências na produtividade da cultura. O trabalho foi conduzido numa área experimental localizada em lavoura comercial de pimenta-do-reino no Distrito de Nestor Gomes, Rodovia ES 381 km 28, no Município de São Mateus, Norte do Estado do Espírito Santo. Na coleta dos dados, utilizou-se uma malha regular de aproximadamente 1,5 ha, totalizado 94 pontos amostrais, espaçados 18 x 12 m entre si. Para a determinação dos atributos, o solo foi coletado na projeção da copa na profundidade de 0 - 0,2 m. A produtividade (kg planta-1) foi avaliada através de duas colheitas, compreendendo a uma safra. Para as avaliações, inicialmente, foi feita uma análise exploratória descritiva sem levar em consideração a posição espacial das amostras para a identificação das medidas de posição, dispersão e de pontos discrepantes (outliers), e, posteriormente, uma análise exploratória espacial, levando em consideração a posição das amostras na área para identificação de possíveis tendências. A análise da variabilidade espacial dos atributos estudados foi determinada pelos semivariogramas escalonados. Por meio do ajuste dos semivariogramas teóricos foram definidos os parâmetros necessários para a estimativa de valores em posições não amostradas no campo, utilizando o método de interpolação por krigagem ordinária, para a confecção dos mapas que possibilitaram a distinção de regiões com menor e maior variabilidade dos atributos avaliados. Com os resultados pode-se concluir que a utilização de técnicas da geoestatística possibilita a identificação de zonas diferenciadas do manejo da fertilidade do solo através do mapeamento dos atributos estudados. Todos os atributos apresentam estrutura de dependência espacial com grau de dependência variando entre forte e moderado, com exceção para os teores de P e Mg que apresentam efeito pepita puro e AG que ajusta-se ao modelo linear. A regressão múltipla linear identifica o K, Ca e Mg, respectivamente, como sendo os atributos químicos de maior influência na determinação da produtividade, e o mapa da produtividade da pimenta-do-reino predito pela regressão múltipla espacial mostra comportamento espacial similar com o mapa da produtividade da cultura estimado por krigagem.
158

Investigating Metrics that are Good Predictors of Human Oracle Costs An Experiment

Kartheek arun sai ram, chilla, Kavya, Chelluboina January 2017 (has links)
Context. Human oracle cost, the cost associated in estimating the correctness of the output for the given test inputs is manually evaluated by humans and this cost is significant and is a concern in the software test data generation field. This study has been designed in the context to assess metrics that might predict human oracle cost. Objectives. The major objective of this study is to address the human oracle cost, for this the study identifies the metrics that are good predictors of human oracle cost and can further help to solve the oracle problem. In this process, the identified suitable metrics from the literature are applied on the test input, to see if they can help in predicting the correctness of the output for the given test input. Methods. Initially a literature review was conducted to find some of the metrics that are relevant to the test data. Besides finding the aforementioned metrics, our literature review also tries to find out some possible code metrics that can be ap- plied on test data. Before conducting the actual experiment two pilot experiments were conducted. To accomplish our research objectives an experiment is conducted in the BTH university with master students as sample population. Further group interviews were conducted to check if the participants perceive any new metrics that might impact the correctness of the output. The data obtained from the experiment and the interviews is analyzed using linear regression model in SPSS suite. Further to analyze the accuracy vs metric data, linear discriminant model using SPSS pro- gram suite was used. Results.Our literature review resulted in 4 metrics that are suitable to our study. As our test input is HTML we took HTML depth, size, compression size, number of tags as our metrics. Also, from the group interviews another 4 metrics are drawn namely number of lines of code and number of <div>, anchor <a> and paragraph <p> tags as each individual metric. The linear regression model which analyses time vs metric data, shows significant results, but with multicollinearity effecting the result, there was no variance among the considered metrics. So, the results of our study are proposed by adjusting the multicollinearity. Besides, the above analysis, linear discriminant model which analyses accuracy vs metric data was conducted to predict the metrics that influences accuracy. The results of our study show that metrics positively correlate with time and accuracy. Conclusions. From the time vs metric data, when multicollinearity is adjusted by applying step-wise regression reduction technique, the program size, compression size and <div> tag are influencing the time taken by sample population. From accuracy vs metrics data number of <div> tags and number of lines of code are influencing the accuracy of the sample population.
159

ESTUDO DO CONTROLE DE H2S (SULFETO DE HIDROGÊNIO) E CO2 (DIÓXIDO DE CARBONO) EM UMA PLANTA DE PRODUÇÃO DE ÓLEO E GÁS NA CAMADA PRÉ-SAL / STUDY OF CONTROL OF H2S (HYDROGEN SULPHIDE) AND CO2 (CARBON DIOXIDE) IN A PLANT FOR OIL AND GAS PRODUCTION IN PRE-SALT LAYER

Guedes, Marcus 21 December 2012 (has links)
The offshore industry is full ascension in Brazil, driven by the discovery of light oil and rich gas abundant in the pre-salt layer. The explored natural gas in the pre-salt layer has superior calorific components, however it has H2S and CO2 (considered acid components) dissolved in its composition. The removal of such components is necessary still in the production field, seeking to fit the gas in the effective specifications for ANP - National Agency of the Petroleum. Nowadays the most used method to remove acid components from the extracted gas of the pre-salt layer is through amine plants. With that comes the need to know the process and to operate it in the most efficient possible way, treating the same amount of gas with the minimum cost. The need for research arises from the difficulty from FPSO Capixaba s operation part to maintain the specifications of the manufacturer s project (VME Process), as the concentration of the amine solvent, amount of treated fresh water and new amine daily added inside the system. To maintain the established project levels it was necessary superior addition both of solvent amine as treated fresh water, showing a removal of H2S and CO2 sometimes satisfactory sometimes not. So, the aim of this investigation was to propose the best possible point of operation for the amine plant in operation in FPSO Capixaba through a study case, between May of 2010 to June of 2012 and was built scatter plots based on historical data to find the ideal concentration that the system operates with the best efficiency on H2S and CO2 removal, using minimum daily addition of amine and treated fresh water. The results were confronted with specifying it in projects and applied, resulting in an economy in order 75,8% amine and 76% of treated fresh water monthly, maintaining the treated gas in the system between of the specifications and effective standards in Brazil. A statistic technique of multiple regressions was built for the study of relationship between the water/amine concentration and of H2S and CO2. It was obtained a total of samples of 245 days for amine concentration (classified as dependent variable) and an equation that esteemed it relationship was built with CO2 and H2S concentration (considered independent variables). The results obtained in the model indicate a good relationship in the estimators studied (R2(adjusted) = 0,8051) and a standard error of 0,029. / A indústria offshore encontra-se em plena ascensão no Brasil, impulsionada pela descoberta de óleo leve e gás rico, abundantes na camada pré-sal. O gás natural explorado na camada pré-sal possui componentes caloríficos superiores, porém possui H2S e CO2 (considerados componentes ácidos) dissolvido em sua composição. A remoção de tais componentes se faz necessária ainda no campo de produção, visando enquadrar o gás nas especificações vigentes pela ANP Agência Nacional do Petróleo. Atualmente o método mais utilizado na remoção de componentes ácidos no gás extraído da camada pré-sal é através de plantas de amina. Com isso surge a necessidade em conhecer o processo e operá-lo da maneira mais eficiente possível, tratando a mesma quantidade de gás com o menor custo. A necessidade da pesquisa surge da dificuldade por parte da operação do FPSO Capixaba para manter as especificações de projeto do fabricante (VME Process), quanto à concentração da amina solvente, quantidade de água tratada e amina nova inserida diariamente no sistema. Para manter os níveis estabelecidos em projeto se fazia necessário à adição muito superior tanto de amina solvente quanto de água tratada, apresentando uma remoção de H2S e CO2 horas satisfatória horas não. Assim o objetivo desta investigação foi propor o ponto de operação melhor possível para a planta de amina em operação no FPSO Capixaba através de um estudo de caso, tendo como base o período de Maio de 2010 até Junho de 2012 e, para isso utilizouse a construção de gráficos de dispersão baseado em dados históricos para encontrar a concentração ideal em que o sistema opera com a melhor eficiência com relação a remoção de H2S e CO2, menor adição de amina e água tratada diariamente. Os resultados foram confrontados com o especificando em projetos e aplicados no processo, resultando em uma economia na ordem 75,8% amina e 76% de água tratada mensalmente, mantendo o gás tratado no sistema dentro das especificações e normas vigentes no Brasil. Foi construído um modelo de regressão múltipla para estudo da relação entre a concentração de água/amina e a concentração de H2S e CO2. Obteve-se um total de amostras de 245 dias para concentração de amina (classificada como variável dependente) e buscou-se uma equação que estimasse a sua relação com a concentração de CO2 e H2S (consideradas variáveis independentes). Os resultados obtidos no modelo indicam uma boa relação nos estimadores estudados (R2(ajustado)= 0,8051) e um erro padrão de 0,029.
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Vulnérabilité des ouvrages en maçonnerie à des mouvements de terrain : méthodologie d'analyse par méthodes statistiques et par plans d'expériences numériques sur les données de la ville de Joeuf / Vulnerability of masonry structures to ground movement : methodology of analysis by statistical methods and numerical experimental designs applied on Joeuf city data

Abdallah, Mouhammed 06 May 2009 (has links)
Le contexte de l’étude est celui des mouvements de terrain susceptibles de se produire à la suite d’un affaissement minier caractéristique de Lorraine et de leurs conséquences sur les habitations en maçonnerie traditionnelle. Quand de tels affaissements se produisent, ces habitations subissent en effet des désordres qui résultent des efforts engendrés dans la structure par les mouvements du terrain. La réponse qui caractérise alors l’état global de la structure dépend des caractéristiques géométriques, physiques et mécaniques. Or, la nature discontinue des maçonneries et la complexité des interactions entre blocs dans ces maçonneries rend complexe et difficile la détermination de cette réponse. Il en est de même de l’interaction sol-structure. L’objectif de la recherche consiste donc à étudier, par modélisation numérique avec la méthode des éléments distincts et par la technique des plans d’expérience et des surfaces de réponse, le comportement d’ouvrages en maçonnerie soumis à un affaissement minier caractéristique et à dégager de cette étude des critères permettant d’estimer, à l’échelle d’une ville entière, la vulnérabilité de tous ses bâtiments en maçonnerie. Une première analyse simplifiée expose le principe de la démarche mise en œuvre à l’échelle de la ville de Joeuf, utilisée comme site pilote. Elle repose sur l’analyse de la longueur cumulée des joints ouverts, assimilés à la formation de fissures dans la structure. Ensuite, une analyse typologique permet de distinguer 4 groupes de maisons aux caractéristiques proches. Sur chacun de ces groupes, la démarche est ensuite appliquée de manière systématique. Elle prend en considération des caractéristiques géométriques des façades et aboutit à la formulation de fonctions de vulnérabilité qui font appel à la technique de régression orthogonale / The context of our study concerns ground movements that may occur in Lorraine as a result of mining subsidence events and their impact on traditional masonry houses. When such an event occurs, houses suffer disorders resulting from efforts in the structure caused by the movement of the ground. The response that characterizes the state of the structure depends on the geometrical, physical and mechanical characteristics. However, the discontinuous nature of the masonry and the interactions complexity between masonry blocks makes it difficult to determine that response. The same is true about the soil-structure interaction. The purpose of this research is to study, by numerical modelling with the distinct element method, experimental design planning and response surfaces, the behaviour of masonry structures subjected to a typical mining subsidence event and to define from this study some criteria making possible the estimation of the vulnerability of all the buildings of a city. A first simplified analysis describes the principle of the used methodology which is then applied to the study of all houses of the city of Joeuf, used as a pilot site. This methodology is based on an analysis of the total length of the opened joints, which are considered as similar to cracks in the structure. Then, a typology analysis helps first to distinguish 4 groups (types) of houses which have similar characteristics. On each of these groups, the methodology is applied consistently, based on the geometrical characteristics of the houses facades and then leads to the formulation of vulnerability functions that use the technique of orthogonal regression

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