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Porovnání opotřebení renovovaných pracovních orgánů kypřiče Kverneland CLC a jejich ekonomické zhodnoceníHOLEČEK, Tomáš January 2019 (has links)
This thesis deals with the differences of various types of working tools of the Kverneland CLC Pro cultivator. Under specific conditions of the agricultural enterprise in the Czech Republic, it compares ordinary turning tine, carbide tine, Knock-on tine and renovated tine. In the introduction, there is a general overview of the properties of the soil, followed by an overview of various methods of soil cultivation, which are also related to various methods of founding plants. Furthermore, I summarized the types of cultivators and tillers, followed by an overview of the types of wear tines with their advantages and disadvantages. In the practical part of the work there is the monitoring of the lifetime of the compared technologies, the time required for their replacement, the cost of their acquisition and the overall economic evaluation.
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Développement et application de méthodes de caractérisation pour la compréhension de la stabilité de modules photovoltaïques organiques fabriqués au déroulé / Development and application of characterization methods applied to stability studies of organic photovoltaic modules manufactured by roll to rollLlobel, Marc-Antoine 02 April 2019 (has links)
Afin de limiter son impact environnemental, un dispositif photovoltaïque doit être performant, durable dans le temps et fabriqué avec un procédé peu énergivore. Depuis 2 décennies les cellules photovoltaïques organiques ont vu leurs rendements se décupler (14 % atteint en 2018) les rendant de plus en plus compétitives avec les technologies dominant le marché.Les dispositifs organiques commerciaux sont généralement produits par impression réalisée à l’air ambiant et possèdent donc des coûts de fabrication relativement faibles. La durée de vie de ces systèmes variera selon les matériaux mis en jeux et selon l’environnement d’utilisation et reste un point faible de la technologie . Un nombre important de groupes présentent des études de durée de vie sur des dispositifs de petites surfaces et dont le procédé de fabrication n’est pas au stade industriel. Le travail présenté dans ce manuscrit a été mené en collaboration avec ARMOR et le CEA-INES et a pour but de présenter l’application de méthodes de caractérisations et d’analyses non destructives, permettant d’expliquer l’évolution sous illumination des modules photovoltaïques organiques (OPV) produits au déroulé sur ligne pilote. Nous présenterons le développement et l’utilisation de méthodes d’imagerie (électroluminescence, photoluminescence), de caractérisations I(V) sous illumination variable et de modélisation, permettant de comprendre les différences observées sur les performances après fabrication et après vieillissement. Un comparatif entre des cellules et des modules OPV sera également établi. Ce travail a ainsi permis de mettre en évidence les disparités existantes au sein de modules issus d’un même procédé de fabrication. De plus, certaines causes de dégradation de ces modules sous illumination ont été identifiées et des solutions sont proposées pour y remédier. / In order to limit its environmental impact, a photovoltaic device must be efficient, sustainable and manufactured with a process that consumes low energy. In the last two decades organic photovoltaic cells have seen their efficiency increase tenfold (14% reached in 2018) making them more and more competitive with market-leading technologies (Si, thin films).Commercial organic devices are generally produced by printing in ambient air and therefore have relatively low manufacturing costs. The lifespan of these systems will vary with the materials involved and the applied stress and remains a weak point of the technology . A large number of research groups present lifetime studies on small scale devices produced at lab-scale. This work was conducted in collaboration with ARMOR and CEA-INES and aims at presenting the application of non-destructive characterization and analysis methods, to explain the evolution under illumination of organic photovoltaic modules (OPV) produced by roll-to-roll on an industrial pilot line. We will present the development and use of imaging methods (electroluminescence, photoluminescence), variable illumination measurement and modeling to explain the differences in performances after manufacturing and after aging between cells and OPV modules. This work has thus made it possible to highlight the disparities existing within modules and cells resulting from the same manufacturing process. In addition, some of the causes of degradation of these modules under illumination have been identified and mitigation strategies have been proposed.
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Fluorescence lifetime spectroscopy for diagnosis of clinically similar skin lesions / Espectroscopia de tempo de vida de fluorescência para o diagnóstico de lesões de pele clinicamente semelhantesNogueira, Marcelo Saito 28 July 2016 (has links)
The fluorescence spectroscopy and lifetime analysis in biological tissues has been presented as a technique of great potential for tissue characterization for diagnostic purposes. This potential is due to the main advantages of optical techniques based on fluorescence for diagnosis, which includes the possibility of evaluating the tissue metabolism in situ, without removal and processing of the biological sample, through a fast and non-invasive response. Skin lesions were the target interrogated tissue in the present study. They can be clinically classified into two major groups: pigmented and non-pigmented lesions. In each group, the clinical discrimination of benign and malignant lesions may be a complex task, especially for non-experienced clinicians. When these lesions have clinically similar features, the choice of the treatment modality becomes difficult. In this context, auxiliary diagnostic techniques are very important to improve the diagnostic resolution as well as treatment planning and success. Gold standard for skin diagnosis is obtained with the biopsy and further histological analysis. The information about these features is invasive and time consuming. When using a non-invasive procedure such as fluorescence lifetime measurements, the main interrogated fluorophores are NADH (nicotinamide adenine dinucleotide) and FAD (flavin adenine dinucleotide), biomolecules involved in cellular respiration that may provide information on the metabolism of the cells. To differentiate each skin lesion, it is necessary to take into account the contribution of endogenous fluorophores emission such as collagen and elastin, and the absorption of chromophores such as melanin and hemoglobin. In addition to fluorescence decay analysis considering the contribution of fluorophores and chromophores, a stable and portable system is desired for clinical measurements and interrogation of biological tissue in vivo. In this study, we have assembled, calibrated, and characterized one of the worlds first portable time-resolved fluorescence spectroscopy system for single-point measurements. This system was designed to be robust and user-friendly for clinical applications. The system was calibrated and characterized in vitro before the clinical application. It was used for evaluation of the photoaging process in sun-exposed and non-exposed skin and for discrimination of clinically similar skin lesions. Significant statistical differences were observed for 10 parameters when comparing normal and photoaged skin (students t-test, p < 0.001), and for all combinations of non-pigmented and pigmented lesions when using tri-exponential decay parameters (Wilcoxon rank sum test, p<0.05). Both in vivo measurements showed promising results and have potential for many applications in dermatology, oncology and aesthetics. Next steps include multivariate data analysis and the determination of the diagnostic resolution of fluorescence lifetime spectroscopy. Further investigation of optical processes related to fluorescence decay changes is necessary, since fluorescence lifetime values in biological tissues reported on the literature are very scarce and heterogeneous and not completely understood. / A análise da espectroscopia e do tempo de vida da fluorescência em tecidos biológicos vem sendo apresentada como uma técnica com grande potencial para a caracterização tecidual com finalidade diagnóstica. Esse potencial é devido às principais vantagens das técnicas ópticas de diagnóstico baseadas em fluorescência, que possibilitam avaliar o metabolismo in situ, sem a necessidade de remoção e processamento da amostra biológica, com uma resposta rápida e não-invasiva. Lesões de pele foram os tecidos investigados no presente estudo. Elas podem ser clinicamente classificadas em dois grandes grupos: pigmentadas e não pigmentadas. Em cada grupo, a discriminação clínica de lesões benignas e malignas pode ser uma tarefa complexa, principalmente para médicos com pouca experiência. Quando essas lesões apresentam características clínicas semelhantes, a escolha do tipo de tratamento torna-se difícil. Nesse contexto, técnicas auxiliares de diagnóstico são de grande relevância para melhorar a resolução de diagnóstico, assim como o planejamento e o sucesso do tratamento. O padrão ouro para o diagnóstico do câncer de pele é obtido por meio da biópsia e posterior análise histopatológica. A obtenção de informações sobre essas características é invasiva e consome bastante tempo. Ao utilizar procedimentos não-invasivos como medidas de tempo de vida de fluorescência, os fluoróforos de mais investigados são o NADH (nicotinamida adenina dinucleotídeo) e o FAD (flavina adenina dinucleotídeo), biomoléculas envolvidas na respiração celular que podem fornecer informação sobre o metabolismo das células. Para diferenciar cada tipo de lesão de pele, é necessário levar em conta a contribuição da emissão de fluoróforos endógenos como o colágeno, elastina e da absorção de cromóforos como melanina e hemoglobina. Além da análise do decaimento de fluorescência considerando a contribuição de fluoróforos e cromóforos, um sistema estável e portátil é desejado para medidas clínicas e investigação de tecidos biológicos in vivo. Nesse estudo, nós montamos, calibramos e caracterizamos um dos primeiros sistemas portáteis do mundo para espectroscopia de fluorescência resolvida no tempo para medidas pontuais. Esse sistema foi projetado para ser robusto e amigável ao usuário em aplicações clínicas. O sistema foi calibrado e caracterizado in vitro antes das aplicações clínicas. Ele foi utilizado para avaliação do processo de fotoenvelhecimento em pele exposta e não-exposta ao sol e para a discriminação de lesões de pele clinicamente semelhantes. Diferenças estatísticas significativas foram observadas para 10 parâmetros na comparação entre pele normal e fotoenvelhecida (teste t-student, p<0.001) e para todas as combinações de lesões pigmentadas e não-pigmentadas ao utilizar parâmetros do decaimento triexponencial (teste Wilcoxon rank sum, p<0.05). Ambas medidas in vivo mostraram resultados promissores e um potencial para muitas aplicações em dermatologia, oncologia e estética. As próximas etapas incluem análise multivariada de dados e determinação da resolução de diagnóstico da espectroscopia de tempo de vida de fluorescência. Uma maior investigação dos processos ópticos relacionados a mudanças nos decaimentos de fluorescência é necessária, pois o número de valores de tempo de vida de fluorescência em tecidos biológicos reportados na literatura é escasso e os valores são heterogêneos e não completamente compreendidos.
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Estudo teórico-experimental do transitório da corrente de dreno e do tempo de vida de geração em tecnologias SOI MOSFETs. / Theoretical-experimental study of the drain current transient and generation lifetime in SOI MOSFETs technologies.Galeti, Milene 16 May 2008 (has links)
Este trabalho apresenta um estudo sobre o transitório da corrente de dreno e métodos de extração de tempo de vida de geração em transistores SOI MOSFETs parcialmente depletados de porta simples, porta dupla e FinFETs de porta tripla. Este estudo foi baseado tanto em simulações numéricas bidimensionais como em dados experimentais extraídos a partir de transistores fabricados no IMEC (Interuniversity Microelectronics Center), que fica na Universidade Católica de Leuven (KUL) na Bélgica. Inicialmente foi analisada a influência da espessura do óxido de porta e da temperatura na extração do tempo de vida de geração dos portadores utilizando o transitório da corrente de dreno. Nesta análise, além do tempo de vida de portadores, outros parâmetros elétricos também foram estudados, como a tensão de limiar, o potencial de superfície na primeira interface e a energia de ativação para criação de um par elétron-lacuna. Com o estudo da influência dos parâmetros de processo no método de determinação do tempo de vida de geração foi possível propor um modelo simples para estimar o tempo de geração dos portadores em função da temperatura. Este modelo foi aplicado experimentalmente e comparado com resultados obtidos através de simulações apresentando um erro máximo de 5%. Fez-se uma análise detalhada do impacto da presença da região de implantação de HALO na extração do tempo de vida de geração baseando-se no transitório da corrente de dreno. Os resultados obtidos através deste estudo possibilitaram a proposta de um novo modelo. O modelo proposto considera tanto o impacto da lateralidade não uniforme da dopagem do canal no efeito de corpo flutuante, devido à presença das regiões de implantação de HALO, como também as cargas controladas pelas junções de fonte e dreno, o que até então não havia sido alvo de estudo na literatura. Com as novas considerações tornou-se possível à análise do transitório da corrente de dreno com a redução do comprimento de canal. A sensibilidade do novo modelo foi ensaiada com a variação de ± 20% nas concentrações da região de canal e de implantação de HALO resultando em um erro máximo de 9,2%. A maior eficiência do acoplamento da porta nos dispositivos de porta dupla, comparando com os de porta única, foi observada através do estudo do comportamento do potencial de corpo destas estruturas. Esta análise resultou na inserção de um parâmetro dependente da espessura do filme de silício, possibilitando a extrapolação do modelo proposto neste trabalho também para os dispositivos de porta dupla. Os resultados obtidos apresentaram um ajuste bastante satisfatório com a variação do comprimento de canal, temperatura e com a variação das concentrações de dopantes da região de canal e da região de implantação de HALO. Por fim, é apresentado um estudo sobre o transitório da corrente de dreno em dispositivos FinFETs de porta tripla, com e sem a região de implantação de HALO, considerando a variação da largura de canal. Através da análise da tensão de limiar, transcondutância e do transitório da corrente de dreno foi possível observar que os dispositivos sem a presença da região de implantação de HALO são mais susceptíveis a influência dos efeitos de corpo flutuante. / This work presents a study of drain current switch-off transients and extraction methods of the generation lifetime in partially depleted SOI nMOSFET transistors of single gate, double gate and triple gate FinFETs. This study is accomplished through two-dimensional numerical simulations and compared with experimental data of devices fabricated in the IMEC (Interuniversity Microelectronics Center), which is in the Catholic University of Leuven (KUL) in Belgium. Initially, it was analyzed the gate oxide thickness and temperature influences on the carrier generation lifetime extraction using the drain current transient. Beyond the generation lifetime, other electric parameters were also analyzed, such as the threshold voltage, the surface potential and the activation energy. Based on process parameter influence study in the determination method of the generation lifetime, it was possible to propose a simple model in order to estimate the carrier generation lifetime as a function of the temperature. This model was experimentally applied and compared to simulated results and it presented a maximum error of 5%. A detailed analysis of the effect of HALO implanted region in the generation lifetime extraction was based on the drain current transient. The results obtained through this study made possible the proposal of a new model. The proposed model considers not only the laterally non-uniform channel profile due to the presence of a HALO implanted region but also the amount of charge controlled by drain and source junctions, a never-before-seen topic in the literature. The new model sensitivity was tested with a ± 20% variation of the doping concentration of the channel and implanted HALO region resulting in a maximum error of 9.2%. Taking the obtained results into consideration, it was possible to analyze the drain current as a function of the channel length reduction. The great efficiency presented by the gate in double gate devices, compared to the single gate ones, was observed through the study of the body potential behavior in this structure. This analysis resulted in the inclusion of a silicon film thickness dependent parameter that made possible the adaptation of the proposed model in this work also for double gate devices. The obtained results presented a good agreement with the channel length variation, temperature and with the doping concentration variation in the channel and HALO implanted region. Finally, it was presented a study about the drain current transient in triple gate FinFET devices, with and without the HALO implanted region, taking the geometric parameter variation into consideration. Through the analysis of the threshold voltage, the transconductance and the drain current transient of the devices, it was possible to observe that the devices without HALO are remarkably more susceptible to the floating body effects influence.
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Propriedades ópticas de tetrâmeros de anilina em solução / Optical properties of aniline tetramers in solutionsBoni, Leonardo de 05 October 2000 (has links)
Neste trabalho são estudadas algumas propriedades ópticas de tetrâmeros de anilina em solução, usando o dimetil sulfóxido (DMSO) como solvente. Os espectros de absorção e emissão permitiram uma determinação aproximada dos níveis de energia do tetrâmero. Para a caracterização das propriedades ópticas não lineares foram utilizadas as técnicas de varredura-Z resolvida em freqüência e com trem de pulsos. Com a primeira foram determinados os parâmetros térmicos relacionados ao solvente, enquanto que com a segunda foram caracterizadas as não linearidades eletrônicas associadas aos estados excitados das moléculas. Além disso, foi possível obter a dinâmica das não linearidades presentes nas soluções, que apresentam um processo acumulativo relacionado à formação de uma lente térmica induzida pelo perfil gaussiano do laser. / This work reports on the optical properties of aniline tetramers in dimethyl sulfoxide (DMSO) solutions. Absorption and emission spectra allowed a rough estimate of the energy levels of the aniline tetramers. Nonlinear optical properties were studied with the frequency resolved Z-scan technique and with the Z-scan technique with pulse trains. The former determined the thermal parameters of the solvent, while the latter characterized electronic nonlinearities associated to molecular excited states. Moreover, we could analyze the dynamics of the optical nonlinearities and verify the presence of an accumulative process related to thermal lensing.
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Optimization of a Technique for Phosphorescence Lifetime Imaging of Oxygen Tension in the Mouse RetinaKight, Amanda C. 30 April 2002 (has links)
Retinal hypoxia and inadequate oxygen delivery have been implicated as causal for the development of several eye diseases, including diabetic retinopathy, glaucoma, and retinopathy of prematurity. The imaging of oxygen tension in the retina, generated from a measure of the phosphorescence lifetimes of bolus-injected palladium-porphyrin probes, has been used successfully to study retinal oxygen dynamics in numerous animal models. However, the specific parameters for applying this technique in the mouse have not been thoroughly investigated. The goals of this project were to calibrate a newly-constructed phosphorescence lifetime imaging instrument and data analysis software against known oxygen concentrations, to determine specific parameters for probe excitation and image collection and analysis in the mouse eye, and to assess any damage caused to the eye by the technique using histological analysis. An in vitro system was developed for calibration of the probe and for estimation of power of excitation light and camera settings necessary to produce acceptable oxygen maps. In vivo experiments were then performed, and plots indicating camera settings necessary for producing varying qualities of oxygen maps were constructed. Trypsin digestion of retinal tissue was used in an attempt to assess any damage to experimental subjects, but this histological technique was deemed inadequate for analyzing the capillary structures of the mouse eye. Alternatively, damage was assessed using the instrument itself to calculate changes in oxygen tension during the experimental process. The results of this work will allow the phosphorescence lifetime imaging system to be used in the mouse to study how changes in retinal oxygen tension correlate with the progression of eye diseases where oxygen is implicated, including diabetic retinopathy.
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Valor do cliente, inadimplência e assimetria de fluxo de caixaOngaratto, Samuel 20 August 2010 (has links)
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Previous issue date: 2010-08-20 / Nenhuma / O objetivo deste estudo é ajudar as empresas na tomada de decisão com relação à base de clientes e ajuste de suas promoções de mercado num contexto de risco de crédito comercial. O resultado da pesquisa é a proposição de um novo modelo. Como contribuições teóricas, pode ser citado o desenvolvimento de um modelo de risco de crédito capaz de estimar um risco de inadimplência para cada pagamento efetuado por um cliente. Isso difere dos modelos encontrados na literatura, que estimam apenas um risco para cada cliente. Outra contribuição é o desenvolvimento de um modelo baseado na métrica de Customer Lifetime Value com componentes inéditos (assimetria entre prazos de pagamento e recebimento e risco de crédito). Esta pesquisa é dividida em três fases distintas: uma fase exploratória, resultado de uma pesquisa realizada na literatura em busca de conceitos e elementos alinhados ao objetivo; a segunda é a proposição do método e do modelo propriamente ditos, e a terceira e última fase foi a aplicação do modelo a um estudo de campo, o qual utilizou dados de 14.259 faturas e 229 clientes. Os dados são de dezembro de 2007 a agosto de 2009. O modelo de risco de crédito integrado ao modelo proposto classifica as faturas pagas com 75,52% de assertividade média. Os resultados do estudo de campo ajudaram a empresa estudada a realizar uma série de mudanças na sua base de clientes, resultando com essas medidas num ganho estimado de mais de R$ 2,5 milhões para 2010. / The objective of this research is to help companies in decision making regarding the customer base and adjust their marketing promotions in the context of commercial credit risk. The result of this research is to propose a new model. As theoretical contributions can be mentioned the development of a model of credit risk can estimate a default risk for each payment made by a client. This differs from the other models in the literature that estimate only one risk for each client. Another contribution is the development of a model based on metrics of Customer Lifetime Value with components unpublished (asymmetry between receiving and payment terms and credit risk). This research is divided into three distinct phases: an exploratory phase, where it performed a literature review in search of concepts and elements aligned to the goal. The second phase is the proposition of the method and the model itself. The third and final phase was the implementation of the model to a field study. The field study used data from 14 259 bills and 229 customers. Data are from December 2007 to August 2009. The model of credit risk built into the proposed model classifies invoices paid on average 75.52% of assertiveness. The results of the field helped the company studied conducting a series of changes in its customer base. Changes made resulting in an estimated gain of more than R$ 2.5 million in 2010.
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Gestão de clientes : um framework para integrar as perspectivas do portfólio de clientes e do cliente individual / Customer management : a framework for integrating customer portfolio and customer perspectivesSilveira, Cleo Schmitt January 2016 (has links)
A gestão de clientes é um processo que envolve a tomada de decisões estratégicas, que influenciam a composição do portfólio de clientes da companhia, e operacionais, que afetam o relacionamento dos clientes com a empresa no dia a dia. O framework sugerido nesta tese propicia a integração dessas duas perspectivas, permitindo aos gestores alocarem melhor os recursos de marketing, por possibilitarem (a) o incremento da eficiência da carteira de clientes, a partir da sua otimização, e (b) a identificação dos clientes mais propensos a gerarem lucros futuros, com base na modelagem de customer lifetime value (CLV) desenvolvida. A abordagem de otimização do portfólio de clientes foi elaborada para auxiliar os gestores a definirem os segmentos que devem ser alvo dos investimentos de marketing e tem como objetivo indicar a composição da carteira de clientes que proporcionará a rentabilidade, a diversificação do risco e a lucratividade desejadas pelos acionistas. A abordagem sugerida é uma adaptação para o marketing da teoria financeira do portfólio. Foram incluídas restrições específicas para a área de gestão de clientes que asseguram a exequibilidade dos portfólios recomendados, tanto em relação à necessidade de aquisição de clientes ou de redução da participação dos segmentos na carteira, quanto em relação à manutenção da lucratividade da empresa. Ademais, foram incorporadas opções de estimação do retorno, tais como a inclusão da tendência à série com base na modelagem SUR, além de serem avaliadas a utilização de duas proxies para o risco, a variância e o Conditional Value at Risk. De acordo com o framework de gestão de clientes proposto, a implementação das decisões estratégicas é viabilizada a partir da integração da análise dos resultados obtidos pela otimização com a avaliação proporcionada pelo modelo de CLV sugerido. Este, além de englobar a evolução do comportamento do cliente ao longo do relacionamento da empresa, considera o retorno e a matriz de probabilidade de troca de segmento de maneira individualizada. A heterogeneidade da matriz de Markov foi alcançada a partir da combinação convexa da matriz de transição geral com a matriz personalizada de cada cliente, possibilitando, assim, a priorização de clientes pertencentes a um mesmo segmento. O framework sugerido foi aplicado na base de clientes de uma grande empresa que atua nacionalmente na indústria de serviços financeiros. Após a constatação de que os segmentos podem gerar diferentes retornos e representar distintos níveis de risco para a companhia, foi feita a comparação dos resultados dos portfólios recomendados com o realizado. Os portfólios sugeridos desempenharam melhor de maneira consistente em termos de lucratividade e de eficiência, medida a partir do sharpe ratio. Em relação ao modelo de CLV, os resultados foram comparados com os obtidos a partir do modelo de Pfeifer & Carraway (2000), utilizado como ponto de partida para o seu desenvolvimento. As modificações incorporadas, além de possibilitarem a individualização por cliente, aumentaram a precisão da previsão dos valores individuais e a qualidade do ordenamento, mantendo a capacidade de avaliação do valor da base. Para resumir, foi proposto um framework de gestão de clientes que inclui a avaliação do risco, possibilitando aos gestores uma visão holística do negócio e particular de cada cliente. / Customer management is a process that involves strategic decision-making, which influence the composition of the customer portfolio, and operational decision making, which affect the relationship of each customer with the company. The proposed framework provides the integration of the strategic and operational perspectives, empowering managers to better allocate marketing resources as it enables (a) the increase of the efficiency of the customer portfolio, through its optimization, and (b) the identification of the customers that are more likely to bring profit in the future, through the customer lifetime value (CLV) model developed. The customer portfolio optimization method was built to help managers to define the customer segments that should be the target of their marketing investments. Its purpose is to indicate the customer portfolio composition that will provide the return, profitability and risk diversification desired by shareholders. The suggested approach is an adaptation to marketing of financial portfolio theory. In this way, customer management specific constrains were included to ensure the applicability of the recommended portfolios in terms of either the necessity of acquiring new customers or reducing the importance of a given segment in the portfolio as well as in terms of maintaining the company’s profitability. Furthermore, options of estimating return were incorporated such as the inclusion of the trend in the time series based SUR modeling as well as the optimizations were evaluated considering two proxies for risk, variance and Conditional Value at Risk. According to the proposed framework, the implementation of the strategic decisions concerning the changes needed in the customer portfolio become possible through the integration of the results of the optimization with the estimation of the value of each customer provided by the CLV model developed. In this model, besides accounting for the evolution of the customer behavior throughout the duration of his relationship with the company, we also consider, for each customer, his individual return and his individual transition matrix. The heterogeneity of the Markov matrix was reached with a convex combination of the general transition matrix and the personalized matrix of each customer. It, therefore, enables managers to priorize customers of the same segment. The suggested framework was applied to the customer database of a large national company from the financial services industry. Once evidenced that the customer segments can generate different returns and can have different levels of risk for the company, we compared the results of the recommended with the current. The portfolios suggested by the optimization performed consistently better in terms of profitability and efficiency, measured through sharpe ratio. Concerning the CLV model developed, we compared the results with Pfeifer & Carraway (2000) model, which was used as the start point for our model. The improvements implemented not only allowed the estimation of CLV at the individual level, but also increased the precision of the predictions for the customer lifetime values and for the customer ranking, maintaining the quality of the customer equity forecast. To sum up, our proposed framework which includes risk assessment enables marketing managers to have a holistic vision of their customer portfolio and to drilldown into a particular vision of each customer.
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Enhancing the human sensemaking process with the use of social network analysis and machine learning techniquesMarshan, Alaa January 2018 (has links)
Sensemaking is often associated with processing large or complex amount of data obtained from diverse and distributed sources. Sensemaking enables leaders to have a better grasp of what the data represents and what insights they can get from it. Thus, sensemaking is considered extremely important in mature markets where the competition is fierce. To-date, the research base on sensemaking has not moved far from the conceptual realm, however. In response, this research provides a conceptual framework that explains the core processes of sensemaking - noticing, interpretation and action - and examines how emerging technologies such as Social Network Analysis (SNA) and Machine Learning (ML) techniques help to enhance the human sensemaking process in generating valuable insights during data analysis. Design Science Research (DSR) is adopted as a research methodology in the context of financial transactional data analysis, aiming to make sense of the data while exploring conceptions of customer value for a mainstream commercial bank alongside the perceived need for banking products. Three analytical models are introduced, examining Connected Customer Lifetime Value (CCLV), Network Relationship Equity (NRE) and product purchasing frequency based on customer 'personas'. The former models employ SNA techniques in providing novelty, the latter combines the outcomes of SNA with ML clustering algorithms to provide a base on which product holdings and purchase frequency analysis are overlaid - providing a novel form of recommendation. Ongoing evaluation of the developed models is used to explore the nuances of the sensemaking process and the ability of such models to support that process (in the given domain).
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Fast-timing measurements with a spatially-distributed sourceMallaburn, Michael January 2017 (has links)
The effect of the spatial distribution of a radioactive source on timing measurements has been investigated with particular consideration toward the focal plane of recoil separators. The work conducted during this thesis is a precursor to understand the magnitude of such effects for the upcoming fast timing array (FATIMA) at FAIR. An experiment was undertaken at the University of Jyvaskyla using the K130 cyclotron to accelerate a 36-Ar beam to 190 MeV, directed onto a 106-Cd target, to produce recoils of 138-Gd and 136-Sm via fusion-evaporation reactions. Recoils directed using RITU to the focal-plane DSSSD of GREAT were distributed over the majority of the 124-mm by 40-mm extension of the DSSSD. A new array consisting of eight lanthanum bromide detectors was used to measure the time between coincident prompt-gamma rays emitted following the de-excitation of isomeric recoil states implanted into the DSSSD. Lifetimes were measured to be 213(20) ps and 200(100) ps for the first-excited 2+ states in 138-Gd and 136-Sm, respectively. Positional information, extracted from the DSSSD, was used to correct for the difference in the time-of-flight of gamma rays as they travelled from the implantation position to the lanthanum bromide detectors. When accounted for, the lifetimes were remeasured to be 217(20) ps and 210(90) ps, respectively, showing no significant change in value or error. A method of quantifying the increase in uncertainty of a lifetime measurement due to the spatial distribution of the source and the position of the surrounding detectors, supported by simulation, has been provided to explain these observations. A new technique for extracting the time-walk from each of the CFDs in a multi-detector array has been presented. The new technique offers a reduced complexity in calculations by accounting for the correlated time-walks present in time measurements from different detector-pairs sharing a common CFD. Work towards a technique for extracting lifetimes from time data has been presented. Dubbed the Symmetrised-Convolution Lifetime Measurement (SCLM) method, this technique essentially applies a model-dependent convolution of the prompt-response with nuclear exponential decay on both time spectra, obtained by inverting the start and stop conditions of a TAC, simultaneously and draws parallels to the Mirror Symmetric Centroid Difference method.
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