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Mensuração da estrutura de preferência do consumidor: uma aplicacao de conjoint analysis em marketing / Measuring preference structure of consumer: an application of conjoint analysis in marketingSiqueira, Jose de Oliveira 04 January 1996 (has links)
O objeto desta dissertação é a estrutura de preferência do consumidor (EPC). O objetivo geral é estudar os métodos de mensuração da EPC (MMEPC) e o tema é a mensuração desta estrutura, utilizando a técnica estatística Conjoint Analysis (CA). A CA proporciona uma maneira realista de medir o impacto de cada atributo de um produto na preferência do consumidor. Esta técnica estatística tem sido cada vez mais aplicada em problemas de Marketing. Alguns softwares têm surgido e provocado o aumento de uso desta técnica. A dissertação discute uma aplicação real desta técnica num problema de definição de um tecido de linho ótimo para um conjunto de especialistas. A ênfase está no planejamento do experimento fatorial fracionário para a estimação do modelo individual cuja variável resposta é posto e os atributos são qualitativos. Modelos lineares de célula de referência e de desvios foram construídos para a análise do experimento. Utilizou-se o modelo linear aditivo não-saturado. Alguns dos principais softwares foram analisados: SPSS, SAS, ACA, CBC e CVA. O autor define um projeto de software de planejamento de experimentos fatoriais fracionários ótimos segundo a eficiência-D. O estudo dos MMEPC pode proporcionar as seguintes contribuições à Administração: otimização de projetos de produtos/serviços/conceitos, quantificação da EPC, segmentação de mercado, determinação da probabilidade de escolha ou participação esperada do mercado de produtos/serviços/conceitos num determinado cenário e simulação (predição) de preferências individuais e agregadas. / The purpose of this dissertation is the consumers preference structure (CPS). The general objective is to study the methods of mensurement of CPS (MMCPS) and its main purpose is to measure that structure using the statistical technique Conjoint Analysis (CA). The CA provides a realistic way to measure the impact of the attribute of a product on the consumers preference. This statistical technique is being used more and more in marketing problems. Some softwares have emerged and increased the use of this technique. This dissertation discusses a real application of this technique on the problem of definition of a linen tissue for a specialist group. The emphasis is on the design of a fractional factorial experiment for estimation of a individual model in wich the response variable is rank and the attributes are qualitative. Linear models of a cell of reference and deviations were constructed for the experimental analysis. Used one a non satureded linear model. Some of the main softwares were analysed: SPSS, SAS, ACA, CBC and CVA. The author defines a software project for optimum fractional factorial experimental design and analysis, according to D-efficiency. MMCPS studies can provide the following contribution to Management: products/services/concepts optimization, CPS quantification, marketing segmentation, choice probability determination on the expected participation of the products/services/concepts market in a particular scenario and the simulation (prediction) of individual and aggregate preferences.
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Modelling The Fresh Properties Of Self Compacting Concrete Utilizing Statistical Design Of Experiment TechniquesEroglu, Levent 01 February 2007 (has links) (PDF)
Self compacting concrete (SCC) is first developed in Japan in the late 1980s in order to overcome the consolidation problems associated with the presence of congested reinforcement. It is also termed as a high performance concrete, as it can flow under its own weight and completely fill the formworks. As the fresh properties of SCC are quite important, mix design of a SCC is performed by considering various workability related fresh properties. Therefore, a well designed SCC should satisfy all requirements of a hardened concrete, besides its superior workability properties.
The aim of this research is to assess the effects of some basic ingredients of SCC on the fresh properties of SCC. This will be performed by applying design of experiment techniques and obtaining significant statistical models, which will give valuable information about the effects of the model parameters on the rheology and fresh state characteristics of SCC.
In this research program, four different variables / use of fly ash replacement, use of high range water reducing admixture (HRWRA), use of viscosity modifying admixtures (VMA) and water-cementitious material ratio, are considered as the variables of the experimental design. Central Composite Design (CCD), a design of experiment technique, is employed throughout the experimental program and a total of 21 mixtures of concrete are cast. Slump flow, V-funnel, L-box, sieve segregation, initial and final setting time tests are performed, furthermore / to investigate the effects of these variables to the rheology of SCC, relative plastic viscosity and relative yield stress, which are the parameters of Bingham Model are measured with the help of a concrete rheometer.
As a result of the experimental program, the fresh state properties of SCC are expressed by mathematical equations. Those equations are then used in order to explain the effects of fly ash replacement, HRWRA and VMA concentration, and the w/cm ratio on the fresh state properties of SCC. According to the derived models, it is stated that the water-cementitious material ratio of the concrete mixture is the most effective parameter on the flowability and passing ability of SCC beside the other parameters utilized in this research as its coefficient was the highest in the related models.
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An Experimental Study On Single Crystal Diamond Turning Of Optical Quality SiliconCali, Serdal 01 January 2008 (has links) (PDF)
Silicon is commonly used in infrared (IR) imaging systems. The surface quality is
an important issue in optics manufacturing since surface roughness affects optical
performance of imaging systems. Surface quality of an optical component is
determined by number of factor, including cutting parameters / cutting speed, depth
of cut and feed in radial direction.
In this thesis, an experimental study has been performed to investigate the relation
between cutting parameters and average roughness of the surface of silicon. In the
experiments, silicon specimens, which have a diameter of 50 mm, were face turned
by using a 2-axis CNC single point diamond turning machine. The specimens were
machined by using either constant spindle speed or constant cutting speed. Two
different tools with rake angles of -15 degrees and -25 degrees were used. The
attained surfaces were measured by using a white light interferometer, which has a
resolution of 0.1nm.
The experiments were designed according to the factorial design method,
considering cutting parameters. The effects of cutting parameters and tool rake
angles on surface quality of silicon were observed. The best average surface
roughness obtained was about 1 nm which is quite better than the acceptable
average surface roughness level of 25 nm.
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Cutting Strategies For Forging Die Manufacturing On Cnc Milling MachinesOzgen, Arda 01 March 2008 (has links) (PDF)
Manufacturing of dies has been presenting greater requirements of geometrical accuracy, dimensional precision and surface quality as well as decrease in costs and manufacturing times. Although proper cutting parameter values are utilized to obtain high geometrical accuracy and surface quality, there may exist geometrical discrepancy between the designed and the manufactured surface profile of the die cavities. In milling process / cutting speed, step over and feed are the main cutting parameters and these parameters affect geometrical accuracy and surface quality of the forging die cavities.
In this study, effects of the cutting parameters on geometrical error have been examined on a representative die cavity profile. To remove undesired volume in the die cavities, available cutting strategies are investigated. Feed rate optimization is performed to maintain the constant metal removal rate along the trajectory of the milling cutter during rough cutting process.
In the finish cutting process of the die cavities, Design of Experiment Method has been employed to find out the effects of the cutting parameters on the geometrical accuracy of the manufactured cavity profile. Prediction formula is derived to estimate the geometrical error value in terms of the values of the cutting parameters. Validity of the prediction formula has been tested by conducting verification experiments for the representative die geometry and die cavity geometry of a forging part used in industry. Good agreement between the predicted error values and the measured error values has been observed.
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Scale-up of dispersion for simulation of miscible displacementsAdepoju, Olaoluwa Opeoluwa 07 October 2013 (has links)
Dispersion has been shown to degrade miscibility in miscible displacements by lowering the concentration of the injected solute at the displacement fronts. Dispersion can also improve oil recovery by increasing sweep efficiency. Either way, dispersion is an important factor in understanding miscible displacement performance. Conventionally, dispersion is measured in the laboratory by fitting the solution of one-dimensional convection-dispersion equation (CDE) to the effluent concentration from a core flood. However dispersion is anisotropic and mixing occurs in both longitudinal and transverse directions. This dissertation uses the analytical solution of the two-dimensional CDE to simultaneously determine longitudinal and transverse dispersion. The two-dimensional analytical solution for an instantaneous finite volume source is used to investigate anisotropic mixing in miscible displacements. We conclude that transverse mixing becomes significant with large a concentration gradient in the transverse direction and significant local variation in flow directions owing to heterogeneity. We also utilized simulation models similar to Blackwell's (1962) experiments to determine transverse dispersion. This model coupled with the analytical solution for two-dimensional CDE for continuous injection source is used to determine longitudinal and transverse dispersivity for the flow medium. The validated model is used to investigate the effect of heterogeneity and other first contact miscible (FCM) scaling groups on dispersion. We derive the dimensionless scaling groups that affect FCM displacements and determine their impact on dispersion. Experimental design is used to determine the impact and interactions of significant scaling groups and generate a response surface function for dispersion based on the scaling groups. The level of heterogeneity is found to most significantly impact longitudinal dispersion, while transverse dispersion is most significantly impacted by the dispersion number. Finally, a mathematical procedure is developed to use the estimated dispersivities to determine a-priori the maximum grid-block size to maintain an equivalent level of dispersion between fine-scale and upscaled coarse models. Non-uniform coarsening schemes is recommended and validated for reservoir models with sets of different permeability distributions. Comparable sweep and recovery are observed when the procedure was extended to multi-contact miscible (MCM) displacements. / text
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Multidisciplinary analysis of jet engine components : Development of methods and tools for design automatisation in a multidisciplinary contextHeikkinen, Tim, Müller, Jakob January 2015 (has links)
This thesis report presents the work of analysing current challenges in Multidisciplinary Analysis systems. Exemplary the system of an aerospace supplier, GKN Aerospace Sweden AB, is examined and several suggestions for improve- ment are implemented. The Multidisciplinary Analysis system, with company internal name Engineering Workbench, employs a set-based approach in exploring the design-space for jet engine components. A number of design cases with varied geometrical and environmental parameters is generated using Design of Experiment sampling methods. Each design case is then subjected to a set of analyses. Using the analyses results, a surrogate model of the parts behaviour in relation to the input parameters is created. This enables the product developer to get a general view of the model’s behaviour and also to react to changes in product requirements. Design research methodology is applied to further develop the Engineering Workbench into a versatile design support system and expand the functionality to include producibility assessment. In its original state, the execution of a study requires explicit domain knowledge and programming skills in several disciplines. The execution of a study is often halted by minor process errors. Several methods to improve this status are suggested and tested. Among those are the introduction of an interface to improve the usability and expand the range of possible users. Further the integration of a four level system architecture supporting a modular structure. Producibility assessment is enabled by developing an expert system where geometrical and simulation results can be caught, analysed and evaluated to produce producibility metrics. Evaluation of the implemented solutions indicate a step in the right direction. Further development towards Multidisciplinary Optimisation, involving experts in information technologies as well as case- based reasoning techniques is suggested and discussed.
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Photo-biomodulation of human skin fibroblast sub-populations : a systematic approach for the optimization of optical treatment parametersMignon, Charles January 2017 (has links)
The thesis presents a rational path for the optimization of the selection of optical treatment parameters in photobiomodulation of human skin fibroblasts. The project begins with an extensive analysis of 90 bibliographic reports in photobiomodulation published between 1985 and 2015, and revealed major inconsistencies in optical parameters selected for clinical applications. Seeking greater clarity for optimal parameter choice, a systematic approach to disentangle the multiple factors underpinning the response of human dermal fibroblasts in vitro to visible and near-infra red (NIR) light was employed. Light-based devices were constructed to specifically and systematically screen the optical parameter window (i.e. wavelength, irradiance and dose) observed in literature. Additionally, critical culture and treatment conditions that have dramatic impact on the outcome of specific light treatment of these human skin dermal cells were identified. In particular, environmental oxygen concentration, cell confluency and serum concentration were all found to have a great effect on the response of dermal fibroblasts to light. In parallel, the induction of reactive oxygen species (ROS) by short visible wavelengths on two dermal fibroblast sub-populations or lineage, reticular and papillary, was monitored by live-cell imaging. The ROS species were found to be created in or close to mitochondria. Lastly, gene expression studies revealed a strong impact of short visible wavelengths, as compared to long and NIR wavelengths on both subpopulations of human dermal fibroblasts. In particular, blue light (450 nm) specifically down-regulated proliferation, metabolism and protein synthesis molecular pathways. At the protein level, 450-nm light inhibited the production of procollagen I in human reticular and papillary fibroblasts in a dose-dependent manner. Gene expression results were in agreement i.e., the same light parameter down-regulated collagen fiber genes, integrins and up-regulated collagenase MMP1. This thesis concludes with a chapter presenting a characterization of the accuracy of a potential translation tool for the prediction of optical photon density inside human skin.
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Estudo de transistores a base de óxido de zinco visando aplicações em sensor de radiação ultravioleta / Investigation of zinc oxide transistors for applications in ultraviolet sensorsGomes, Tiago Carneiro 27 March 2018 (has links)
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Previous issue date: 2018-03-27 / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Transistores de filme fino de ZnO, cujo desempenho depende das condições de preparação da camada de ZnO e do dielétrico de gate, tem sido aplicados como sensores de radiação ultravioleta (UV), visando prevenir danos à saúde da pele. Este trabalho tem como objetivo a fabricação de transistores de ZnO/Al2O3, mediante o estudo simultâneo dos parâmetros relacionados à preparação das camadas de ZnO e Al2O3, bem como, o de transistores com dielétrico padrão (ZnO/SiO2) submetidos a diferentes condições de funcionamento. Estes estudos visam encontrar quais condições viabilizam as aplicações dos transistores como sensor UV. Os experimentos englobam a deposição de filmes de ZnO tanto por sputtering de um alvo de ZnO, quanto por spray pirolise de uma solução de acetato de zinco. O dielétrico SiO2 foi obtido comercialmente, enquanto que o Al2O3 foi crescido por anodização. Os transistores foram fabricados em diversas condições, as quais foram estabelecidas pelos métodos de planejamento experimental Taguchi e Plackett-Burman. As respostas das caracterizações foram interpretadas por técnicas de estatística (ANOVA). Os resultados demonstram que Al2O3 otimizado exibe correntes de fuga de até 10E-10 A e constante dielétrica de ~13. A identificação dos parâmetros mais importantes na preparação de filmes de ZnO por spray pirólise, permitiram produzir transistores de ZnO/Al2O3 com mobilidades de ~4,5 cm2/Vs. Os sensores UV, usando transistores de ZnO/SiO2 apresentaram mobilidades de 0,1 a 12 cm2/Vs, e indicaram que a sensibilidade do sensor UV depende de parâmetros relacionados as condições de operação do dispositivo. Portanto, mostra-se que é fundamental a compreensão dos parâmetros envolvidos na produção dos dispositivos, pois isto permite refinar o processo na busca pela alta performance de dispositivos de baixo custo, bem como, otimizar os dispositivos para aplicações como sensor de radiação UV. / ZnO thin film transistors have been applied as ultraviolet (UV) radiation sensors in order to prevent damage to skin's health. However, the performance of ZnO transistor depends on the preparation conditions of both ZnO layer and gate dielectric. This work aims to produce and evaluate ZnO/Al2O3 transistors by studying simultaneously the parameters regarding the preparation of ZnO and Al2O3 layers, as well as the fabrication of ZnO transistors with a standard dielectric (ZnO/SiO2), under different conditions of working. It is intended to investigate the conditions to apply ZnO transistors as UV sensor. The experiments involve the deposition of ZnO films by sputter coating and spray pyrolysis of a solution of zinc acetate. SiO2 dielectric was commercially purchased, while Al2O3 was grown by anodization. The transistors were fabricated under different conditions, which were established by both experimental design Taguchi and Plackett-Burman methods. The responses from the characterization were interpreted by statistical techniques (ANOVA). The results showed that optimized Al2O3 films exhibit leakage current until 10E-10 A and dielectric constant of ~13. It was essential to identify the most important parameters regarding to preparation of ZnO films by pyrolysis spray in order to fabricate ZnO/Al2O3 transistors with mobilities of ~4,5 cm2/Vs. UV sensors based on ZnO/SiO2 transistors showed mobilities from 0,1 to 12 cm2/Vs and demonstrated that the sensitivity of the UV sensor depends on parameters related to working conditions. Therefore, it is of great importance the understanding of the parameters involved in the production of the devices, as it allows to refine the process in the search for the high performance of low cost materials as well as optimize the device for application as UV sensor. / FAPESP: 2014/13904-8
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Análise da influência dos parâmetros de soldagem sobre a geometria do cordão de solda depositado pelo processo de soldagem TIG - MAG em tandemTeixeira, Gustavo Simões January 2011 (has links)
O objetivo deste trabalho é analisar a influência dos parâmetros de um sistema mecanizado de soldagem, composto por uma tocha TIG e outra MAG em tandem, sobre a geometria do cordão de solda resultante. Os resultados obtidos foram comparados com soldas realizadas pelos processos TIG e MAG operando isoladamente. Os testes foram executados por meio de simples deposição de cordões sobre chapas de aço ao carbono AISI 1010 com espessura de 6,3 mm. Os parâmetros analisados foram: corrente de soldagem e distância da ponta do eletrodo até a peça no processo TIG, velocidade de alimentação de arame e tensão do arco no processo MAG, além de velocidade de soldagem e distância entre as tochas. Os cordões de solda foram executados em um dispositivo de soldagem mecanizado, que permite a variação da velocidade de soldagem, distância da ponta do eletrodo TIG e a distância entre as tochas. Os ajustes de corrente e tensão de soldagem foram feitos em duas fontes de potência separadas, ambas do tipo transformador-retificador, uma para cada tocha, devido às diferentes curvas características de cada processo. Através do projeto de experimento fatorial fracionado, foram avaliados os efeitos de dois níveis, um mínimo e outro máximo, mais quatro réplicas dos seus níveis intermediários, resultando em 20 experimentos para cada processo de soldagem. Os valores dos resultados finais indicam uma diferença ao utilizar uma tocha TIG para pré-aquecer o material base, porém, estatisticamente, essa diferença não é significativa entre os processos TIG e MAG em tandem e MAG convencional para a faixa de parâmetros de soldagem adotada. / This study aims to investigate the influence of process parameters of a mechanized welding system, comprising a GTAW torch and a GMAW torch in tandem configuration, on the geometry of the resulting weld bead, performed using GTAW and GMAW welding processes in tandem. The results were compared with weld beads performed by conventional GTAW and GMAW welding processes. The tests were conducted performing bead-on-plate deposits over AISI 1010 6,3 mm thick carbon steel plates. GTAW current, GMAW wire feed speed, GTAW arc length, GMAW voltage, welding speed and the distance between GTAW and GMAW torches were the analyzed parameters. The weld beads were performed in a mechanized welding bench, which allows the variation of speed, distance between torches and arc length of the GTAW torch. Current and voltage adjustments were made in two separate transformer-rectifier power sources, one for each welding torch, due to their different characteristic curves of each process. Through the fractional factorial design of experiment, the effects of two different levels for each parameter were analyzed, plus four replicates of the average values of these levels, resulting in 20 experiments for each welding process. The results show a difference on the weld bead geometry using a GTAW torch to preheat the base metal, however, this difference is not statistically significant between GTAW and GMAW welding process in tandem and GMAW welding process for the adopted range of welding parameters.
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Análise da influência dos parâmetros de soldagem sobre a geometria do cordão de solda depositado pelo processo de soldagem TIG - MAG em tandemTeixeira, Gustavo Simões January 2011 (has links)
O objetivo deste trabalho é analisar a influência dos parâmetros de um sistema mecanizado de soldagem, composto por uma tocha TIG e outra MAG em tandem, sobre a geometria do cordão de solda resultante. Os resultados obtidos foram comparados com soldas realizadas pelos processos TIG e MAG operando isoladamente. Os testes foram executados por meio de simples deposição de cordões sobre chapas de aço ao carbono AISI 1010 com espessura de 6,3 mm. Os parâmetros analisados foram: corrente de soldagem e distância da ponta do eletrodo até a peça no processo TIG, velocidade de alimentação de arame e tensão do arco no processo MAG, além de velocidade de soldagem e distância entre as tochas. Os cordões de solda foram executados em um dispositivo de soldagem mecanizado, que permite a variação da velocidade de soldagem, distância da ponta do eletrodo TIG e a distância entre as tochas. Os ajustes de corrente e tensão de soldagem foram feitos em duas fontes de potência separadas, ambas do tipo transformador-retificador, uma para cada tocha, devido às diferentes curvas características de cada processo. Através do projeto de experimento fatorial fracionado, foram avaliados os efeitos de dois níveis, um mínimo e outro máximo, mais quatro réplicas dos seus níveis intermediários, resultando em 20 experimentos para cada processo de soldagem. Os valores dos resultados finais indicam uma diferença ao utilizar uma tocha TIG para pré-aquecer o material base, porém, estatisticamente, essa diferença não é significativa entre os processos TIG e MAG em tandem e MAG convencional para a faixa de parâmetros de soldagem adotada. / This study aims to investigate the influence of process parameters of a mechanized welding system, comprising a GTAW torch and a GMAW torch in tandem configuration, on the geometry of the resulting weld bead, performed using GTAW and GMAW welding processes in tandem. The results were compared with weld beads performed by conventional GTAW and GMAW welding processes. The tests were conducted performing bead-on-plate deposits over AISI 1010 6,3 mm thick carbon steel plates. GTAW current, GMAW wire feed speed, GTAW arc length, GMAW voltage, welding speed and the distance between GTAW and GMAW torches were the analyzed parameters. The weld beads were performed in a mechanized welding bench, which allows the variation of speed, distance between torches and arc length of the GTAW torch. Current and voltage adjustments were made in two separate transformer-rectifier power sources, one for each welding torch, due to their different characteristic curves of each process. Through the fractional factorial design of experiment, the effects of two different levels for each parameter were analyzed, plus four replicates of the average values of these levels, resulting in 20 experiments for each welding process. The results show a difference on the weld bead geometry using a GTAW torch to preheat the base metal, however, this difference is not statistically significant between GTAW and GMAW welding process in tandem and GMAW welding process for the adopted range of welding parameters.
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