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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
621

Active versus passive portfolio management : A study of risk-adjusted return and market fluctuations on short term and long term

Duveskog, Ida, Halldén, Jesper January 2024 (has links)
Today fund matching is a natural part of Swedes finance and is a popular form of savings that includes a large number of investors in the Swedish fund market. This in turn generates an increased interest in how portfolio managers should locate and acquire knowledge in portfolio selection. This gives a greater interest in how different investment strategies can be affected and generate an investors wealth to an increased level within the stock market, which gives an increased focus to be able to generate as high risk-adjusted return as possible. The study partly presents traditional theory and background on modern portfolio theory and the efficient market hypothesis. Empirical studies also present within the financial market that demonstrate the differences of opinion between how actively versus passively managed funds have performed and which investment strategy is most beneficial for investment.  The purpose of the study is to compare realized return on active versus passive funds during long term, short term and specific time periods that had a lot of economic fluctuations, like bear markets. Within the study 10 actively managed funds and two index measures are selected to be studied and compared based on their respective performance, both within its rise and fall in the Swedish fund market. The performance measures will then be applied to be able to produce the results of the study and to be able to answer whether the active fund’s have any statistically significant over- and underperformance. After conducting single index models and t-test on the 10 active funds, the result of the study shows that despite using two benchmarks index, ten different active funds, long time period, short time period or specific time periods defined by market imbalance , we still resulted in many P-values that was not statistically significant. Active funds failed to overperform against passive funds, but passive funds also failed to outperform our selection of active funds.
622

Modeling and Optimization of Photovoltaic Installations at Urban Scale

Fuster Palop, Enrique 15 January 2024 (has links)
Tesis por compendio / [ES] El sector de la edificación representa el 20% y el 40% de la energía primaria mundial, contribuyendo al 30% de las emisiones de CO2, un desafío amplificado por el crecimiento de la población. Sin embargo, el creciente interés en las fuentes de energía renovables ya maduras, como la energía solar fotovoltaica (PV), ofrece oportunidades para mitigar los anteriores impactos, así como potenciales beneficios económicos, ambientales y sociales. El presente trabajo investiga las posibilidades y limitaciones en el despliegue masivo de sistemas de autoconsumo fotovoltaico (PVSC) en áreas urbanas desde una perspectiva de planificación urbana, considerando las limitaciones técnicas y económicas actuales. Con este fin, esta tesis emplea estrategias basadas en datos para desarrollar modelos físicos y modelos ágiles basados en regresiones como herramientas de evaluación del potencial técnico y económico de los sistemas PVSC en contextos urbanos. En primer lugar, se ha desarrollado y validado un submodelo empírico de producción fotovoltaica con mediciones climáticas y de producción recopiladas de una planta fotovoltaica de 50MW en funcionamiento. Además, se han investigado varias mejoras en el modelado del performance ratio (PR) en entornos de baja irradiancia. En la segunda etapa de esta investigación, el submodelo anterior se ha integrado en un modelo tecnoeconómico 3D basado en sistemas de información geográfica (GIS) capaz de evaluar el PVSC económico para una muestra de edificios residenciales. Además, el modelo incorpora modelos de sombras y estimaciones de demanda eléctrica horaria para evaluar una muestra de edificios residenciales. Una base de datos de simulación, derivada de los resultados anteriores, ha permitido el desarrollo de una metodología para entrenar un modelo basado en regresión y con ello estimar la producción y el periodo de retorno económico (PB) a escala de edificio con una precisión asumible para fines de planificación energética. Como último paso, se mejoró el submodelo de demanda empleando datos reales agregados de series temporales para múltiples patrones de consumo y proporcionando estimaciones realistas para otras tipologías de edificios. Además de las restricciones espaciales, el modelo optimiza el tamaño de las instalaciones según su demanda y limitaciones económicas, maximizando la relación entre autosuficiencia (SS) y el PB. Además, la metodología basada en regresión se ha ampliado para estimar, además del retorno de la inversión, múltiples indicadores clave de desempeño (KPIs) como la tasa interna de retorno (IRR), la tasa de autoconsumo (SC) y SS. A través de una adecuada identificación de predictores y una metodología de entrenamiento y validación, estas correlaciones permitieron estimaciones de rendimiento con una desviación aceptable respecto al modelo físico. La disponibilidad de datos relacionados con la construcción está aumentando progresivamente en la mayoría de los países, lo que permite una amplia aplicación y generalización de las metodologías propuestas y reduce el costo de simulación de estos estudios para cubrir áreas urbanas más extensas. Como aplicación de las metodologías anteriores, se analizaron los resultados del potencial económico fotovoltaico del parque inmobiliario completo de un municipio mediterráneo bajo diferentes escenarios económicos y de demanda a escala de edificio y municipal. Para el escenario que cumple con la regulación actual en España, la SS municipal oscila entre el 22%-43% para los escenarios más optimista y pesimista, respectivamente. El dimensionamiento óptimo de las instalaciones según las curvas de carga en la modalidad de Net Billing (NB) es crucial para obtener resultados económicos competitivos. En consecuencia, la generación fotovoltaica anual representó el 68% del consumo eléctrico total anual. / [CA] El sector de l'edificació representa el 20% i el 40% de l'energia primària mundial, contribuint al 30% de les emissions de CO2, un desafiament amplificat pel creixement de la població. No obstant això, el creixent interés en les fonts d'energia renovables ja madures, com l'energia solar fotovoltaica (PV), ofereix oportunitats per a mitigar els anteriors impactes, així com potencials beneficis econòmics, ambientals i socials. El present treball investiga les possibilitats i limitacions en el desplegament massiu de sistemes PVSC en àrees urbanes des d'una perspectiva de planificació urbana, considerant les limitacions tècniques i econòmiques actuals. A aquest efecte, aquesta tesi empra estratègies basades en dades per a desenvolupar models físics i models àgils basats en regressions com a eines d'avaluació del potencial tècnic i econòmic dels sistemes PVSC en contextos urbans. En primer lloc, s'ha desenvolupat i validat un submodel empíric de producció fotovoltaica amb mesuraments climàtics i de producció recopilats d'una planta fotovoltaica de 50MW en funcionament. A més, s'han investigat diverses millores en el modelatge del performance ràtio (PR) en entorns de baixa irradiància. En la segona etapa d'aquesta investigació, el submodel anterior s'ha integrat en un model tecnoeconòmic 3D basat en sistemes d'informació geográfica (GIS) capaç d'avaluar el PVSC econòmic per a una mostra d'edificis residencials. A més, el model incorpora models d'ombres i estimacions de demanda elèctrica horària per a avaluar una mostra d'edificis residencials. Una base de dades de simulació, derivada dels resultats anteriors, ha permés el desenvolupament d'una metodologia per a entrenar un model basat en regressió i amb això estimar la producció i la període de retorn econòmic (PB) a escala d'edifici amb una precisió assumible per a fins de planificació energètica. Com a últim pas, es va millorar el submodel de demanda emprant dades reals agregats de sèries temporals per a múltiples patrons de consum i proporcionant estimacions realistes per a altres tipologies d'edificis. A més de les restriccions espacials, el model optimitza la grandària de les instal·lacions segons la seua demanda i limitacions econòmiques, maximitzant la relació entre la taxa d'autosuficiència (SS) i PB. A més, la metodologia basada en regressió s'ha ampliat per a estimar, a més del retorn de la inversió, múltiples indicadors clau d'acompliment (KPIs) com la taxa interna de retorn (IRR), la taxa d'autoconsum (SC) i la SS. A través d'una adequada identificació de predictors i una metodologia d'entrenament i validació, aquestes correlacions van permetre estimacions de rendiment amb una desviació acceptable respecte al model físic. La disponibilitat de dades relacionades amb la construcció està augmentant progressivament en la majoria dels països, la qual cosa permet una àmplia aplicació i generalització de les metodologies proposades i redueix el cost de simulació d'aquests estudis per a cobrir àrees urbanes més extenses. Com a aplicació de les metodologies anteriors, es van analitzar els resultats del potencial econòmic fotovoltaic del parc immobiliari complet d'un municipi mediterrani baix diferents escenaris econòmics i de demanda a escala d'edifici i municipal. Per a l'escenari que compleix amb la regulació actual a Espanya, la taxa d'autosuficiència municipal oscil·la entre el 22%-43% per als escenaris més optimista i pessimista, respectivament. El dimensionament òptim de les instal·lacions segons les corbes de càrrega en la modalitat de Net Billing (NB) és crucial per a obtindre resultats econòmics competitius. En conseqüència, la generació fotovoltaica anual va representar el 68% del consum elèctric total anual. / [EN] The building sector in developed countries consumes 20% to 40% of global primary energy, contributing to 30% of the CO2 emissions, a challenge amplified by urban population growth. However, the rising interest in mature renewable energy sources, such as solar photovoltaic (PV), offers opportunities to mitigate these impacts and potential economic, environmental, and social benefits. The present research investigates the possibilities and constraints in the massive deployment of photovoltaic self-consumption (PVSC) systems in urban areas from an urban planning perspective, considering the current technical and economic limitations. To this end, this thesis employs data-driven strategies to develop both bottom-up physical and agile regression-based models as assessment tools for the technical and economic potential of PVSC systems in urban contexts. First, an empirical PV production submodel has been developed and validated with climate and production measurements collected from a 50MW utility-scale in operation. Additionally, several improvements in modeling the performance ratio (PR) in low-irradiance environments have been investigated. In the second stage of this research, the previous submodel has been integrated into a physical 3D GIS-based techno-economic model capable of assessing the economic PVSC for a sample of residential buildings. Additionally, the model incorporates shadow modeling and hourly electric demand estimations to assess sample residential buildings. A simulation database, derived from the previous results, has allowed the development of a methodology to train a regression-based model to estimate the production and the economic payback (PB) at a building scale with an assumable accuracy for energy planning purposes. As the last step, the demand submodel was improved by employing real aggregated time series data for multiple consumer patterns and providing realistic estimations for other building typologies. In addition to spatial restrictions, the model optimizes the sizing of the facilities according to their demand and economic constraints, maximizing the relationship between self-sufficiency (SS) and PB. Furthermore, the regression-based methodology has been extended to estimate, besides the payback, multiple key performance indicators such as internal rate of return (IRR), self-consumption rate (SC), and SS. Through an appropriate predictor identification and a training and validation methodology, these correlations allowed performance estimations with an acceptable deviation compared with the physical model. The availability of building-related data is progressively increasing in most countries, enabling widespread application and generalization of the proposed methodologies and reducing the simulation cost of these studies to cover larger urban areas. As an application of the previous methodologies, a complete-census economic PV potential results of a Mediterranean municipality's building stock was performed under different demand and economic scenarios at a building and municipality scale. For the scenario that meets the current regulation in Spain, the municipality SS ranged between 22%-43% for the most optimistic and pessimistic scenarios, respectively. The optimal sizing of the facilities according to the load curves in the Net Billing (NB) modality is crucial to obtaining competitive economic results. Consequently, the annual PV generation represented 68% of the annual total electricity consumption of the municipality for a net billing scenario, while a net metering scenario represented 103%. Owing to economies of scale and high demand intensity, a higher profitability was found in rooftops of apartment blocks and industrial buildings, which also achieve the highest savings in emissions. / Fuster Palop, E. (2023). Modeling and Optimization of Photovoltaic Installations at Urban Scale [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/202061 / Compendio
623

O mercado de caminhões no Brasil: um estudo econométrico dos determinantes das vendas de veículos

Gonçalves, Carlos Aurélio Bustamante 17 November 2016 (has links)
Submitted by Carlos Aurélio Bustamante Gonçalves (carlos.a.b.goncalves@gmail.com) on 2016-12-01T22:33:16Z No. of bitstreams: 1 carlos gonçalves - Dissertação - o mercado de caminhões no brasil -01122016.pdf: 3390001 bytes, checksum: df0eedc2484f2a8784dda76039181601 (MD5) / Rejected by Fabiana da Silva Segura (fabiana.segura@fgv.br), reason: Boa Noite, Prezado Carlos Peço corrigir alguns itens de formatação conforme segue: - Excluir o acento do nome Getulio nas páginas - Nome deve ser em maiúsculo (alternar, nas páginas que tiver o nome) - Titulo também em fonte maiúscula (alterar nas páginas que contém o título) - No rodapé permanece somente São Paulo - excluir o - SP - Linha de Pesquisa: Finanças e Economia de Empresas, alterar nas páginas que contém a lnha - Excluir na contra capa abaixo no nome do orientado FGV - EAESP - Folha de Assinaturas, alterar a linha de pesquisa e colocar a data de aprovação: 17/11/2016 Peço proceder com as alterações e submeter o trabalho novamente on 2016-12-01T23:28:13Z (GMT) / Submitted by Carlos Aurélio Bustamante Gonçalves (carlos.a.b.goncalves@gmail.com) on 2016-12-02T02:34:57Z No. of bitstreams: 1 carlos gonçalves - Dissertação - o mercado de caminhões no brasil -02122016.pdf: 3391454 bytes, checksum: 7cdcde7e62ecc28be15ec876866cca96 (MD5) / Approved for entry into archive by Fabiana da Silva Segura (fabiana.segura@fgv.br) on 2016-12-02T14:03:17Z (GMT) No. of bitstreams: 1 carlos gonçalves - Dissertação - o mercado de caminhões no brasil -02122016.pdf: 3391454 bytes, checksum: 7cdcde7e62ecc28be15ec876866cca96 (MD5) / Made available in DSpace on 2016-12-02T18:40:07Z (GMT). No. of bitstreams: 1 carlos gonçalves - Dissertação - o mercado de caminhões no brasil -02122016.pdf: 3391454 bytes, checksum: 7cdcde7e62ecc28be15ec876866cca96 (MD5) Previous issue date: 2016-11-17 / Este estudo trata do comportamento da demanda por caminhões novos no Brasil no período de 1996 a 2015 e da investigação dos fatores que a influenciam. Tal questão é relevante devido à escassez de estudos acerca deste tema, ainda que se trate do modo historicamente predominante de transporte de carga no país. O objetivo de pesquisa é determinar e quantificar os fatores que provocam o aumento ou diminuição das vendas de caminhão no Brasil. Para atingir este objetivo, foram construídos modelos econométricos a partir de dados secundários. Proxies utilizadas em outros modelos de demanda automotiva foram confirmadas e refinadas, enquanto novas proxies foram introduzidas com sucesso. Quanto aos resultados, este estudo inovou ao identificar três tipos de determinantes, e ao detalhar os efeitos e defasagens de suas influências: variáveis relacionadas especificamente ao mercado de caminhões, variáveis relacionadas ao PIB e variáveis relacionadas à confiança do comprador. Adicionalmente, realizou-se uma verificação da causalidade entre crédito e vendas, com o surpreendente resultado de que a influência ocorre no sentido de vendas para crédito. Com estes resultados, este estudo dissemina o conhecimento a respeito do comportamento do mercado a toda a cadeia produtiva, melhorando a qualidade das decisões e proporcionando aumento da eficiência para o sistema como um todo. / This is a study on the demand for new trucks in Brazil from 1996 to 2015, and an investigation on the factors that influence it. This topic is relevant due to the scarcity of studies concerning the subject, and due to the overwhelming domination of trucks in cargo transport in Brazil. It aims identify and quantify the variables that drive the sales of trucks. To reach this goal, econometric models were constructed based on secondary data. Variables usually adopted in other studies on automotive demand were confirmed and even refined and new variables were successfully introduced. This study innovates by identifying three groups of variables, and by detailing the effects and the lags of their influence: variables specific to the truck market, variables related to GDP, and variables related to the decision maker’s confidence. Additionally, a causality analysis involving credit and truck sales was performed, unexpectedly resulting in sales causing credit. Through these results, this study disseminates knowledge about the behavior of the truck market to the entire productive chain, contributing to evolve the quality of decisions and the efficiency of the entire system.
624

A Multi-Factor Stock Market Model with Regime-Switches, Student's T Margins, and Copula Dependencies

Berberovic, Adnan, Eriksson, Alexander January 2017 (has links)
Investors constantly seek information that provides an edge over the market. One of the conventional methods is to find factors which can predict asset returns. In this study we improve the Fama and French Five-Factor model with Regime-Switches, student's t distributions and copula dependencies. We also add price momentum as a sixth factor and add a one-day lag to the factors. The Regime-Switches are obtained from a Hidden Markov Model with conditional Student's t distributions. For the return process we use factor data as input, Student's t distributed residuals, and Student's t copula dependencies. To fit the copulas, we develop a novel approach based on the Expectation-Maximisation algorithm. The results are promising as the quantiles for most of the portfolios show a good fit to the theoretical quantiles. Using a sophisticated Stochastic Programming model, we back-test the predictive power over a 26 year period out-of-sample. Furthermore we analyse the performance of different factors during different market regimes.
625

Multispectral imaging of Sphagnum canopies: measuring the spectral response of three indicator species to a fluctuating water table at Burns Bog

Elves, Andrew 02 May 2022 (has links)
Northern Canadian peatlands contain vast deposits of carbon. It is with growing urgency that we seek a better understanding of their assimilative capacity. Assimilative capacity and peat accumulation in raised bogs are linked to primary productivity of resident Sphagnum species. Understanding moisture-mediated photosynthesis of Sphagnum spp. is central to understanding peat production rates. The relationship between depth to water table fluctuation and spectral reflectance of Sphagnum moss was investigated using multispectral imaging at a recovering raised bog on the southwest coast of British Columbia, Canada. Burns Bog is a temperate oceanic ombrotrophic bog. Three ecohydrological indicator species of moss were chosen for monitoring: S. capillifolium, S. papillosum, and S. cuspidatum. Three spectral vegetation indices (SVIs) were used to characterize Sphagnum productivity: the normalized difference vegetation index 660, the chlorophyll index, and the photochemical reflectance index. In terms of spectral sensitivity and the appropriateness of SVIs to species and field setting, we found better performance for the normalized difference vegetation index 660 in the discrimination of moisture mediated species-specific reflectance signals. The role that spatiotemporal scale and spectral mixing can have on reflectance signal fidelity was tested. We were specifically interested in the relationship between changes in the local water table and Sphagnum reflectance response, and whether shifting between close spatial scales can affect the statistical strength of this relationship. We found a loss of statistical significance when shifting from the species-specific cm2 scale to the spectrally mixed dm2 scale. This spatiospectral uncoupling of the moisture mediated reflectance signal has implications for the accuracy and reliability of upscaling from plot based measurements. In terms of species-specific moisture mediated reflectance signals, we were able to effectively discriminate between the three indicator species of Sphagnum along the hummock-to-hollow gradient. We were also able to confirm Sphagnum productivity and growth outside of the vascular growing season, establishing clear patterns of reflectance correlated with changes in the local moisture regime. The strongest relationships for moisture mediated Sphagnum productivity were found in the hummock forming species S. capillifolium. Each indicator Sphagnum spp. of peat has distinct functional traits adapted to its preferred position along the ecohydrological gradient. We also discovered moisture mediated and species-specific reflectance phenologies. These phenospectral characteristics of Sphagnum can inform future monitoring work, including the creation of a regionally specific phenospectral library. It’s recommended that further close scale multispectral monitoring be carried out incorporating more species of moss, as well as invasive and upland species of concern. Pervasive vascular reflectance bias in remote sensing products has implications for the reliability of peatland modelling. Avoiding vascular bias, targeted spectral monitoring of Sphagnum indicator species provides a more reliable measure for the modelling of peatland productivity and carbon assimilation estimates. / Graduate
626

ON-MACHINE MEASUREMENT OF WORKPIECE FORM ERRORS IN ULTRAPRECISION MACHINING

Gomersall, Fiona January 2016 (has links)
Ultraprecision single point diamond turning is required to produce parts with sub-nanometer surface roughness and sub-micrometer surface profiles tolerances. These parts have applications in the optics industry, where tight form accuracy is required while achieving high surface finish quality. Generally, parts can be polished to achieve the desired finish, but then the form accuracy can easily be lost in the process rendering the part unusable. Currently, most mid to low spatial frequency surface finish errors are inspected offline. This is done by physically removing the workpiece from the machining fixture and mounting the part in a laser interferometer. This action introduces errors in itself through minute differences in the support conditions of the over constrained part on a machine as compared to the mounting conditions used for part measurement. Once removed, the fixture induced stresses and the part’s internal residual stresses relax and change the shape of the generally thin parts machined in these applications. Thereby, the offline inspection provides an erroneous description of the performance of the machine. This research explores the use of a single, high resolution, capacitance sensor to quickly and qualitatively measure the low to mid spatial frequencies on the workpiece surface, while it is mounted in a fixture on a standard ultraprecision single point diamond turning machine after a standard facing operation. Following initial testing, a strong qualitative correlation exists between the surface profiling on a standard offline system and this online measuring system. Despite environmental effects and the effects of the machine on the measurement system, the capacitive system with some modifications and awareness of its measurement method is a viable option for measuring mid to low spatial frequencies on a workpiece surface mounted on an ultraprecision machine with a resolution of 1nm with an error band of ±5nm with a 20kHz bandwidth. / Thesis / Master of Applied Science (MASc)

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