Storm water is defined as runoff from precipitation such as rain or snow. It is collected in sewage disposal systems and since it mainly originates from urban areas it can contain high levels of heavy metals, nutrients and oil etc. Polluted storm water is currently treated by different methods such as wet ponds, constructed wetlands and filter strips. This study investigates these methods, which in earlier studies have shown to give varying results regarding their treatment efficiency. This thesis has been written on commission of SWECO VIAK and was aimed at studying those parameters that may affect the treatment efficiency of nutrients and heavy metals in storm water treatment facilities (STF:s). Through literature studies the dominating treatment processes in ponds and wetlands were examined. The flow pattern was then simulated in four different storm water ponds, of varying shape and size, by using a physically based computer model. The residence time distribution for each pond could then be calculated as well as the hydraulic efficiency, which is a measure on how well the inflowing water is spread throughout a pond. Finally a multiple regression analysis was performed. This analysis examined how the reduction of lead, copper, zinc and cadmium depends on the following factors: the specific pond area, the variance of the residence time distribution, the hydraulic efficiency and the concentration of incoming metals and suspended solids. The specific pond area is a factor which is defined as the pond area divided by the reduced run off area. The results from the multiple regression analysis indicate that an increasing content of inflowing suspended solids leads to a better treatment efficiency regarding lead and copper. The specific area showed to have some effect on the treatment efficiency, but this effect was less than that of the content of inflowing suspended solids. The reduction of cadmium depended mainly on the specific area and the incoming concentration of cadmium. An increasing reduction of zinc could to some extent be explained by an increasing specific area. The results from this analysis and earlier studies are emphasizing the fact that adsorption to particles and sediment is one of the main processes for a good separation of heavy metals from storm water. Longer measurements series from additional treatment facilities are needed to build a statistical model which, in the future, can be used to predict the treatment efficiency of storm water ponds. / Dagvatten är regn- och smältvatten som samlas upp i avloppssystem. Då detta vatten huvudsakligen härstammar från urban bebyggelse så kan det innehålla höga halter tungmetaller, närsalter och olja med mera. Idag behandlas förorenat dagvatten bland annat genom nyttjande av dammar, våtmarker och översilningsytor. Dessa behandlingsalternativ har dock visat sig ge varierande resultat med avseende på dess reningseffektivitet. Detta arbete har utförts på uppdrag av konsultföretaget SWECO VIAK och syftade till att studera vilka parametrar som påverkar reningseffekten av närsalter och tungmetaller i dagvattendammar. Genom litteraturstudier undersöktes de dominerande reningsprocesserna i dammar och våtmarker. Därefter modellerades strömningen i 4 dammar med varierande form och storlek. Vid detta arbete erhölls en fördelning av uppehållstiden hos vattnet för respektive damm samt ett värde på den hydrauliska effektiviteten, vilken är ett mått på hur väl det inströmmande vattnet sprids ut i dammen. Slutligen utfördes en multipel regressionsanalys. Vid denna analys undersöktes hur reningen av bly, koppar, zink och kadmium beror av den specifika dammarean, variansen hos vattnets uppehållstidsfördelning, den hydrauliska effektiviteten samt inkommande metall- och TSS-koncentration (suspenderat material). Den specifika dammarean är en faktor vilken defineras som kvoten mellan dammens area och dess reducerade avrinningsområde. Resultaten från den multipla regressionen tyder på att en ökad inkommande halt av suspenderat material till dammen har störst betydelse för en förbättrad avskiljning av bly och koppar. Även den specifika arean och metallkoncentrationen i inflödet visade sig ha en viss, men något mindre, betydelse. Reduktionen av kadmium berodde däremot till störst del av den specifika arean och inkommande kadmiumkoncentration. En ökad reduktion av zink förklarades till viss del av en ökad specifik area. Resultatet att halten av suspenderat material i hög grad avgör reningen samt tidigare studier understryker det faktum att adsorption till partiklar och sediment verkar vara en av de viktigaste processerna för en god avskiljning av tungmetaller. Längre mätserier från fler dagvattendammar krävs dock för att i framtiden ta fram en statistisk modell vilken skulle kunna användas till att prediktera reningseffekten.

Directional and horizontal drilling operations are increasingly conducted in all over the world, especially parallel to the growth of the technological developments in the industry. Common application fields for directional and horizontal drilling are in offshore and onshore when there is no way of drilling vertical wells. During directional and horizontal well drilling, many additional challenges occur when compared with vertical well drilling, such as limited weight on bit, harder hole cleaning, trajectory control, etc. This makes even harder to select the proper drilling parameters for increasing the rate of penetration. This study aims to propose a rate of penetration model considering many drilling parameters and conditions. The proposed model is a modified Bourgoyne &amp / Young&rsquo / s model which considers formation compaction, formation pressure, equivalent circulating density, and effective weight on bit, rotation of the bit, bit wear, hole cleaning, inclination, fluid loss properties and bit hydraulics. Also, a bit wear model is developed for roller cones and PDCs. The model performance is tested using field data obtained from several directional and horizontal offshore wells drilled at Persian Gulf. It is observed that the model can estimate rate of penetration with an error of &plusmn / 25 % when compared with the field data.

Real-time optimization of drilling parameters during drilling operations aims to optimize weight on bit, bit rotation speed for obtaining maximum drilling rate as well as minimizing the drilling cost. The process is considered to be formation specific. A statistical method such as multiple linear regression technique has been used for the drilling optimization. An extensive literature survey on drilling optimization was conducted for this research study. A model is developed for this purpose using actual field data collected through modern well monitoring and data recording systems, which predicts the rate of drilling penetration as a function of available parameters. The rate of penetration general equation is optimized for effective functions at each data point. In order to optimize the parameters in the field, a computer network is required to be developed. The computer network will keep the piped data directly from the data source, and continuously be collecting the new data to be fed. A database present at the central computer will be continuously calculating the developed model parameters by means of multiple regression technique and inform the team at the field. The field engineer will transmit the current drilling parameters back to the central computer, and the headquarters will determine the new model parameters and optimum drilling parameters by including the recently received information. Therefore, there will be a real-time-optimization process. It is considered that this technique is going to be widely used in future drilling activities since it could reduce drilling costs and minimize probability of encountering problems due to working with optimized parameters. It has been found that drilling rate of penetration could be modelled in real-time environment as a function of independent drilling variables such as weight on bit, rotation speed of the string, drilling fluid weight, and formation characteristics. The ability to have the drilling rate of penetration with respect to depth characteristically with certain parameters for specific formations on real-time basis could bring new insights to the nature of drilling optimization studies. Any significant departure of the actual rate of penetration from the predicted rate of penetration trend could have important indications which could be detected beforehand in real-time. The study has also achieved one of its objectives, giving the optimized independent drilling parameters found following statistical synthesis.

The transfer of technology to developing countries constitutes one of the major debates in the literature on development economics. The present empirical investigation is intended to contribute to the large existing literature on technological transfer. Its major contribution lies in demonstrating rigorously that the integration of foreign technologies is greatly affected by the socio-economic conditions of the recipient countries. The present study attempts to identify the main socioeconomic characteristics involved in assimilating transferred technlogy. It first provides a quantifiable measure of the rate of technological absorption. Then, in presenting the selection of indicators, the general procedures followed in choosing the sample of countries are summarized and the principles guiding the choice of variables are examined. The model is based on multiple regression analysis, which is discussed in some detail. Another statistical method is used to explore the interdependence of the economic and social indicators, which provides more exact knowledge about their various interactions and lays the groundwork for the problem at hand. Three main indicators are identified that explain a significant-. sixty one percent of the total variance of the dependent variable. These main indicators are the rate of education, trade policies and the availability of certain consumer products. It is found that these variables express different and important dimensions of the third world economy. In general, the results reveal that the rate of technology integration varies greatly with the level of socio economic development. The findings of the investigation are analysed using new and efficient methods of diagnostic techniques, and are also seen within their theoretical perspectives. The analysis of results is concluded with a discussion of intangible factors that cannot as yet be quantified; factors such as political and managerial quality and yet can be expected to have significant effects on the rate of technological integration.

Given the increase in popularity of Lifetime Value (LTV), the argument is that the topic will assume an increasingly central role in research and marketing. As such, the decision to assess the state of the field in Lifetime Value Modelling, and outline challenges unique to choice researchers in customer relationship management (CRM). As the research has argued, there are an excess of issues and analytical challenges that remain unresolved. The researcher hopes that this thesis inspires new answers and new approaches to resolve LTV. The scope of this project covers the building of a LTV model through multiple regression. This thesis is exclusively focused on modelling tenure. In this regard, there are a variety of benchmark statistical techniques arising from survival analysis, which could be applied, to tenure modelling. Tenure prediction will be looked at using survival analysis and compared with "crossbreed" data mining techniques that use multiple regression in concurrence with statistical techniques. It will be demonstrated how data mining tools complement the statistical models, and show that their mutual usage overcomes many of the shortcomings of each singular tool set, resulting in LTV models that are both accurate and comprehensible. Bank XYZ is used as an example and is based on a real scenario of one of the Banks of South Africa. / Thesis (M.Sc. (Computer Science))--North-West University, Vaal Triangle Campus, 2009.

The purpose of this study was to investigate if there is an association between perceived visual ergonomics work conditions, visual well-being and health and visual performance at the Swedish Tax Agency by a digitalized questionnaire. The questionnaire was sent to ninety-four respondents. Out of them, eighty-six participants, 54 women (63%), 31 men (36 %) and 1 person (1%) who did not want to be identified with any gender answered the questionnaire. Multiple regressions analysis investigated the association between visual ergonomics work conditions and visual performance, with and without visual well-being and health used as a mediator. Screen time outside of work was used as a covariate in all analysis. Descriptive results reported visual ergonomics (M=8.86, SD=2.06), visual well-being and health (M=10.40, SD=11.02) and visual performance (M=15.72, SD=9.51). Results from the multiple regression analysis displayed a significant association between visual ergonomics and visual well-being and health (r2=.098, β=.254, p<0.05) and between visual ergonomics and self-rated visual performance (r2=.304, β=.307, p<0.01). When visual well-being and health was used as a mediator, the association between visual ergonomics and self-rated visual performance remained the same (r2=.310, β=.295, p<0.01). Conclusion drawn from this study was that a reduction in visual performance seemed to occur in isolation from any impact of visual well-being and health. / Tidigare forskning visar att det finns en etablerad relation mellan visuell ergonomi och anställdas välmående samt att det finns en etablerad relation mellan visuellt välmående och prestation. Forskning har dock ännu inte har kunnat skildra om och i sådana fall hur den visuella ergonomin påverkar den anställdes visuella prestation. Eftersom det fanns en forskningslucka och en brist på kunskap inom denna specifika forskningsfråga, var det motiverat att utforska dessa fenomen på en djupare plan. Syftet med föreliggande studie var att undersöka associationen mellan självskattade visuella ergonomiska arbetsförhållanden, subjektivt visuellt välbefinnande och självskattad visuell prestation på Skatteverkets kontor i en mellanstor stad i Sverige. För att besvara syftet användes följande specifika frågeställningar: ”I vilken utsträckning är de visuella ergonomiska arbetsförhållandena associerade med subjektivt välbefinnande?”, ”I vilken utsträckning är de visuella ergonomiska arbetsförhållandena associerade med självskattad visuell prestation?” samt ”I vilken utsträckning är de visuella ergonomiska arbetsförhållandena associerade med självskattad visuell prestation, när subjektivt visuellt välbefinnande fungerar som en medieringsvariabel?”. En elektronisk enkät skickades ut till 94 medarbetare där de fick skatta deras upplevda visuella ergonomiska arbetsförhållanden, deras visuella välmående och deras visuella prestation. För att besvara frågeställningarna användes multipla regressioner samt en medieringsanalys. Skrämtid utanför arbete användes som kovariat i samtliga analyser. Åttiosex av nittiofyra respondenter besvarade enkäten och den deskriptiva statistiken visade visuell ergonomi (M=8.86, SD=2.06), visuellt välbefinnande (M=10.40, SD=11.02) och visuell prestation (M=15.72, SD=9.51). Vidare visade det statistiska huvudresultatet att det fanns en signifikant association mellan visuell ergonomi och visuell välmående (r2=.098, β=.254, p<0.05) och mellan visuell ergonomi och självskattad prestation (r2=.304, β=.307, p<0.01). När associationen medierades av visuell välmående och hälsa var förhållandet detsamma (r2=.310, β=.295, p<0.01). Slutsatser som togs utifrån studien var att visuell prestation kan försämras på grund av dålig visuell ergonomi, oberoende av ett visuellt välbefinnande. Om det fanns något annat fenomen än visuellt välbefinnande som medierar detta förhållande, ligger det bortom modellen i denna studie.

To reduce greenhouse gas emissions in the atmosphere and protect the environment, Swedish cities are heavily invested in sustainable development by developing pedestrian roads and intensifying public transport. Their goal is to make the population less dependent on cars by facilitating accessibility to transit transport. The urban area of ​​Umeå (Sweden), which is experiencing an annual increasing of it population due to urban development, includes 244 km of pedestrian or bike routes and an intensified bus network. The purpose of this paper is to evaluate the walking accessibility of the population at bus stops and to analyze the socio-economic relationship. The use of GIS tools allowed to calculate the proportion of the population and the houses around the bus stop, the average distance accessibility. The use of 3D allowed the observation of access constraints related to the topography and to calculate the slope. The use of the multiple regression model has analyzed the relationship between the shortest accessibility distance and the socio-economic factors that are the income, gender and age. The results show that the average distance of access to the bus stop is 186m. 99.2% of the population lives within 800m from the bus stops. The results of the regression showed that income is the main factor that pushes people to take the bus and live in certain types of housing. The observation of the 3d map and the calculation of the slope made it possible to know the neighborhoods established in the hill and whose residents are susceptible to spend more energy than the other inhabitant living on flat ground. The results mean that most people living in the urban area of ​​Umeå have good access to the bus stop whatever the social group, the level of income and the type of housing.

The variability in crop production oleraceous affects planning and the quality of experiments, inflating the experimental error, and leading to erroneous conclusions with low experimental precision and reliability. The objectives of this study were to scale the number of plants and crops necessary for there to be improving the precision of estimates of production in vegetable crops, test geostatistics and modeling tool and verify the spatial dependence of fruit production of vegetable crops. From the blank experiments production data, obtained from protected cultivation with crops of zucchini, peppers and snap beans, the Department of Agronomy of the Federal University of Santa Maria, was applied the response surface model with variable dependent on the coefficient of variation and independent plot size and number of samples. Semivariograms were made in production data processed in indicators with the average cutoff point, in different simulations of plot sizes and crop groupings, and set the theoretical models spherical, exponential and Gaussian. For the zucchini the best combination of plot size and the number of crops, is seven base units and half of the production cycle, in both growing seasons. For the peppers, using 23 basic units and three harvests per plot grouped, regardless of seasonal growing season, yields greater experimental precision. For bean-to-pod lower coefficients of variation are in plots with 12 basic units (24 plants), for cultures performed in the greenhouse and field and 14 basic units for crops in the tunnel, the seasonal fall-winter season. In seasonal spring-summer season the plot size was 15 basic units for crops and the tunnel to the field. Seasonal stations in both the best grouping to use the harvest was complete. Theoretical models of spherical semivariogram, exponential and Gaussian estimates show weak spatial dependence. The average fresh weight of the fruit has random distribution within the farming environments not influenced plot size or number of harvests. / A variabilidade produtiva em cultivos olerícolas afeta o planejamento e a qualidade de experimentos, inflacionando o erro experimental, e levando a conclusões errôneas, com baixa precisão experimental e confiabilidade. Os objetivos deste estudo foram dimensionar o número de plantas e colheitas necessárias para que haja melhoria da precisão nas estimativas de produção em culturas olerícolas, testar a geoestatística como ferramenta de modelagem e verificar a dependência espacial entre a produção de frutos dos cultivos olerícolas. A partir dos dados de produção de experimentos em branco, realizados em cultivo protegido com as culturas de abobrinha italiana, pimentão e feijão-vagem, no Departamento de Fitotecnia da Universidade Federal de Santa Maria, foi aplicado o modelo de superfície de resposta, com variável dependente o coeficiente de variação e, independentes, o tamanho de parcela e o número de colheitas. Foram realizados semivariogramas dos dados de produção transformados em indicadores tendo a média como ponto de corte, em diferentes simulações de tamanhos de parcela e agrupamentos de colheita, sendo ajustado os modelos teóricos esférico, exponencial e gaussiano. Para a abobrinha italiana a melhor combinação entre o tamanho de parcela e o número de colheitas, é de sete unidades básicas e metade do ciclo produtivo, em ambas estações de cultivo. Para o pimentão, com o uso de 23 unidades básicas por parcela e 3 colheitas agrupadas, independente da estação sazonal de cultivo, obtém-se maior precisão experimental. Para o feijão-de-vagem os menores coeficientes de variação são em parcelas com 12 unidades básicas (24 plantas), para os cultivos realizados em estufa e campo e de 14 unidades básicas para os cultivos em túnel, na estação sazonal outono-inverno. Na estação sazonal primavera-verão o tamanho de parcela foi de 15 unidades básicas para os cultivos a túnel e a campo. Em ambas estações sazonais o melhor agrupamento de colheita foi a utilização do total. Os modelos teóricos de semivariograma esférico, exponencial e gaussiano estimados apresentam fraca dependência espacial. A média da massa fresca de frutos possui distribuição aleatória dentro dos ambientes de cultivo não sofrendo influência do tamanho de parcela ou do número de colheitas realizadas.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Along the Brazilian poultry production history, large volumes of data are generate by computational tools or manually collected on production environment. This data may be have implicit patterns, from which is possible to extract new answers to questions that can enhance the production scale. In this sense, this work was developed with a database from Languiru Cooperative of Teutônia, Rio Grande do Sul. Were evaluating lots of 112 associated producers in a five years period, from 2007 to 2012, a total of 2319 observations, and the broiler farms are located in different regions of cooperative scope. Data were tabulated and subsequently submitted to multiple regression analysis, comparison of means and data mining process. The results show that the environmental conditions and the altitude influence broiler production, changing the mortality and weight gain, it nas possible establish mortality and weight gain regression models, involving altitude and environmental variables. / Ao longo do histórico de produção avícola brasileira, grandes volumes de dados vêm sendo gerados por ferramentas computacionais ou de forma manual diretamente no ambiente de produção. Nestes dados, podem haver padrões implícitos, a partir dos quais é possível extrair novas respostas para questões que podem potencializar a produção em escala. Assim, foi desenvolvido o trabalho a partir de um banco de dados, oriundo de Cooperativa Languiru da cidade de Teutonia, no Rio Grande do Sul. Foram avaliados lotes de 112 associados da cooperativa, no período de 5 anos, compreendendo os anos de 2007 a 2012. As granjas localizam-se nas diferentes regiões que compreendem a abrangência da empresa, totalizando 2319 lotes. Os dados foram tabulados e posteriormente submetidos à análise de regressão múltipla, de comparação de médias e a mineração de dados. Os resultados demonstram que as variáveis ambientais, bem como a altitude influenciam no desempenho das aves, alterando a mortalidade e o ganho de peso, foi possível estabelecer modelos de predição de mortalidade e ganho de peso envolvendo a altitude e as variáveis ambientais.

Conselho Nacional de Desenvolvimento Científico e Tecnológico / The continuous search for information that will assist agricultural practices is today relevant, being the primary use of methodologies to facilitate the determination of relevant parameters in the agricultural productivity. Alternative methods for determining the physical and hydro soils can auxiliary in the monitoring of agricultural activity. Among these, the use stands of pedotransfer functions (FPTs), among other properties, provide an indirect measure of water retention of soil, reducing cost, time and manpower. This study aims to use multiple linear regression models to determine the FPTs for the soils of southern Uruguay to the practical use at laboratories in soil physics, to obtain the curve of retention. For the realization of the work, used 251 samples of superficial, intermediate and inferior soils of southern Uruguay, available in the database of physical analysis of the INIA (Instituto Nacional de Investigación Agropecuaria). This database consists of information of soil texture (percentage sand, silt and clay), bulk density, porosity of the soil, besides the information of water content at potentials of 0, -3, -30, -100, -500 and -1500 kPa. The organization of the database was organized randomly, which is subdivided into two banks, one with 60% of the data (development of FPTs) and the other with 40% of the data (validation of FPTs). The data used to develop the FPTs were included in the Statistical Analysis System (SAS), in its method of determining equations of multiple linear regression (stepwise). Being generated FPTs to estimate water retention at potentials of -30, -100, -500 and -1500 kPa for the superficial layers (0-20 cm), intermediate (20-40 cm) and bottom (40-60 cm ) of the soil profile. The equations presented in its constitution datas textural and structural soil and observed that the statistical indicators mean error and root mean square error squared values were near zero, indicating good accuracy in the determination of residual moisture through the FPTs. In general can say that the attribute structure, water content remaining in the soil after application potential of -3 kPa, was significant in all the FPTs developed. We conclude that the FPTs developed to estimate the water content remaining in the soil at potentials of -30, - 100, -500 and -1500 kPa were good, could be used as an alternative in the construction of water retention curve in soils that have characteristics that fall under the requirements of the FPTs developed for the soils of southern Uruguay. / A busca contínua por informações que venham a auxiliar nas práticas agrícolas é fato relevante nos dias atuais, sendo primordial a utilização de metodologias que facilitem a determinação de parâmetros determinantes na produtividade agrícola, primando pela facilidade e agilidade nas determinações. Métodos alternativos para determinação das características físicohidricas dos solos podem auxiliar no monitoramento da atividade agrícola. Dentre estes, salienta-se o uso de funções de pedotransferência (FPTs) que, entre outras propriedades, possibilitam a determinação indireta da curva de retenção de água do solo, reduzindo custos, tempo e mão-de-obra. O presente estudo objetiva utilizar de modelos de regressão linear múltipla para determinação de FPTs para os solos do Sul do Uruguai, visando a utilização prática destas em laboratórios de física do solo, para a obtenção da curva de retenção dos mesmos. Para a realização do trabalho foram utilizadas 251 amostras das camadas superficial, intermediária e inferior de solos do Sul do Uruguai, disponíveis no banco de dados de análises físicas do INIA (Instituto Nacional de Investigación Agropecuaria). Esse banco de dados é composto por informações de textura do solo (percentuais de areia, silte e argila), densidade do solo, porosidade total do solo, além das informações do conteúdo de água nos potenciais de 0, -3, -30, -100, -500 e -1500 kPa. A organização do banco de dados foi realizada de forma aleatória, sendo este subdividindo em dois bancos, um com 60% dos dados (desenvolvimento das FPTs) e o outro com 40% dos dados (validação das FPTs). Os dados utilizados para o desenvolvimento das FPTs foram inseridos no programa Statistical Analysis System (SAS), em seu método de determinação de equações de regressão linear múltipla (Stepwise). Sendo geradas FPTs para estimar a retenção de água nos potenciais de -30, -100, - 500 e -1500 kPa, para as camadas superficial (0-20 cm), intermediária (20-40 cm) e inferior (40-60 cm) do perfil do solo. As equações obtidas apresentaram em sua constituição atributos texturais e estruturais do solo, sendo observado que, os indicadores estatísticos erro médio e raiz quadrada do erro médio ao quadrado apresentaram valores próximos a zero, indicando boa acurácia na determinação da umidade residual através das FPTs estimadas. De modo geral pode-se afirmar que, o atributo estrutural, conteúdo de água remanescente no solo após aplicação de potencial de -3 kPa, foi significativo em todas as FPTs desenvolvidas. Conclui-se que as FPTs desenvolvidas para estimar o conteúdo de água remanescente no solo nos potenciais de -30, -100, -500 e -1500 kPa apresentam-se satisfatórias, podendo ser utilizadas como alternativa na construção da curva de retenção de água em solos que apresentem características que o enquadrem nos requisitos das FPTs desenvolvidas para os solos do Sul do Uruguai.