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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.
611

Evaluation environnementale des systèmes agricoles urbains en Afrique de l'Ouest : Implications de la diversité des pratiques et de la variabilité des émissions d'azote dans l'Analyse du Cycle de Vie de la tomate au Bénin / Environmental assessment of urban agricultural systems in West Africa : Implications of the diversity of practices and the variability of nitrogen emissions for the Life Cycle Assessment of tomato from Benin

Perrin, Aurélie 20 December 2013 (has links)
L’agriculture urbaine représente une opportunité de réduire la pauvreté et d’améliorer la sécurité alimentaire des habitants des villes d’Afrique de l’Ouest. L’objectif général de cette thèse est de produire des données d’inventaire représentatives ainsi qu’une évaluation environnementale robuste de ces systèmes de production par la méthodologie Analyse du Cycle de Vie (ACV). Notre cas d’étude a été la tomate des jardins urbains au Bénin. Notre état de l’art nous a permis d’identifier que prendre en compte la diversité des systèmes de production et la variabilité des émissions au champ étaient deux enjeux majeurs de l’ACV des produits maraîchers. Nous avons donc développé un protocole de collecte de données basé sur la typologie qui prend en compte la diversité des systèmes puis mis au point une méthode d’estimation des flux d’azote au champ combinant un bilan d’azote et l’usage d’un modèle biophysique. Nous avons ainsi créé des inventaires pour 6 types de systèmes et une moyenne pondérée représentative de la population étudiée. L’analyse des performances agronomiques de ces systèmes a montré une forte variabilité des rendements et une utilisation fluctuante et souvent excessive d’engrais et de pesticides. L’exploration de la variabilité des flux d’azote à l’échelle de la parcelle et du cycle de culture a permis l’identification de 4 facteurs majeurs: les volumes d’eau d’irrigation, la dose d’azote, le pH du sol et la capacité au champ. A l’aide de scénarios favorables et défavorables aux émissions pour chacun de ces 4 facteurs, nous avons montré que leurs effets sur les résultats d’ACV étaient importants. L’intégration de ces données dans une ACV finalisée a montré qu’un hectare de production de tomate au Bénin était plus impactant que les productions maraichères Européennes. Les avantages du climat favorable du sud Bénin à la production de tomate en contre saison sont annulés par les faibles performances des systèmes d’irrigation, l’usage fréquent d’insecticides et d’importantes émissions azotées. Des données mesurées et des connaissances nouvelles sont nécessaires sur ces systèmes pour valider et affiner nos conclusions. / Urban agriculture provides opportunities to reduce poverty and ensure food safety for cities inhabitants in West Africa. The general objective of this thesis is producing representative inventories and a robust environmental assessment for those production systems using the Life Cycle Assessment (LCA) methodology. Our case study was the tomato production in urban gardens in Benin. Our state of the art identified the integration of the diversity of systems and the variability of field emissions as two major challenges for the LCA of vegetable products. We therefore developed a typology-based protocol to collect cropping systems data that includes their diversity and an approach combining a nitrogen budget and the use of a biophysical model to estimate nitrogen field emissions. We created inventories for 6 cropping system types and one weighted mean representative for the urban tomato growers in Benin. The analysis of the agronomical performances of these systems highlighted the important yield variability and the variable and often excessive use of pesticides and fertilizers. The investigation of nitrogen fluxes variability at plot and crop cycle scales led to the identification of 4 major influencing factors: water use, nitrogen input, soil pH and field capacity. Using favorable and unfavorable scenarios for nitrogen emissions for each of these 4 factors, we demonstrated that the LCA results were sensitive to their variations. The implementation of LCA using those contrasted data showed that one hectare of tomato production in Benin was more impacting than European vegetable productions. The benefits from the favorable climate for producing out-of-season tomatoes were hampered by the low efficiency of irrigations systems, the frequent use of insecticides and large nitrogen emissions. Measured data and new knowledge on these systems are needed to validate and refine our conclusions.
612

Ocenenie spoločnosti OKD, a.s. / Valuation of OKD, a.s.

Šišo, Peter January 2014 (has links)
Master thesis deals with current trends on coal market, relationships between prices of coal and prices of other commodities, forecasting of coal prices in fifteen years horizon utilizing statistical tools and business valuation of a company from coal mining industry. Master thesis further analyzes a sensitivity of the company value on changes in projected prices of coal and other commodities.
613

Vyhodnocení investičního záměru: Výstavba bioplynové stanice Smržice / Investment project evaluation: Construction of the biogas power plant Smržice

Kalista, Michal January 2013 (has links)
The investor has to decide whether he realizes the investment in the biogas power plant Smržice with a certain installed capacity If implemented, the investor is entitled to the government-guaranteed purchase price of electricity fixed for 15 years. It is necessary to predict profits and cash flows of each period which are further used for dynamic investment evaluation methods for the purpose of investment decision making. The application of the net present value shows whether the investment project is acceptable or not. The sensitivity analysis is used to compare changes in inputs with its impact on the net present value. The biogas power plant Smržice is typical example of biogas power plants built in Czech Republic in 2011-12 due to the government economic support, so finally these conclusions are generalised for the whole branch of electricity production from biogas.
614

Ocenění investičního projektu / Real estate project valuation

Dokulilová, Vlasta January 2014 (has links)
The master's thesis deals with the evaluation of a specific investment opportunity on the private equity real estate market in the Czech republic. The analysed investment project offers rare opportunity to create additional cash flow to the project under the management of the new owner. The theoretical part will define the core problematic of investment decision making process and the evaluation of investments. Practical part is focused on building a projection of cash flow and analysis of various return scenarios by using the internal rate of return as a key financial criteria to evaluate the investment opportunity.
615

Posouzení možnosti uplatnění výrobkového portfolia v dalších balkánských státech / The evaluation of the product portfolio applicability in other Balkan states

Shtjefni, Geis January 2012 (has links)
The aim of this thesis is to analyse the current situation in the marketability of the products of the particular company, which operates in the territory of Albania in the production of ceramic bricks. After that their possible application to current markets as well as considering the possibility of expansion to other Balkan states. The thesis further explains the reasons leading the company to consider the expansion.In the thesis there has been evaluated the current economic situation of the company, a survey of the business environment about countries being considered for expansion has been made as well as the research of the competitors in the given area. An important part of this thesis is the selection of the forms of entry into the selected foreign markets by using selected methods and tools of managerial decision making.
616

Podnikatelský plán - Fotovoltaická elektrárna v Rumunsku / Photovoltaic power plant in Romania

Brothánek, Ondřej January 2012 (has links)
Renewable energy resources, especially photovoltaics, have experienced enormous boom all over the world in the past few years. It was completely the same in Czech Republic where you would not find anybody without his own opinion regarding PV business. Installation of PV power plants has become very attractive business, with very significant role in 2011 in Czech Republic. At this time, this solar boom has found its "home" in other European countries, particularly in Eastern Europe. The post of the new Eastern Europe's "powerhouse" can defend even Romania, that's the cause I have chosen this country as the subject of this thesis. The aim of this thesis is to create a business plan for PV power plant and evaluate the investment opportunity of its installation in Romania. And then by means of a sensitivity analysis find out the impact of external factors that can significantly affect the profitability of the project.
617

Hodnocení investičního projektu společnosti Moravia Sport Group s.r.o / Evaluation of investment project of the company Moravia Sport Group s.r.o.

Dudová, Martina January 2012 (has links)
The topic of the thesis is an evaluation of a real investment project of the company Moravia Sport Group s.r.o. with regard to the current and projected development of macro area, competitive environment and financial analysis results. The aim of this thesis is to give recommendations for the management of the company in order to decide whether to realize or reject the intended project. The theoretical part summarizes the basic analysis, the stages of the investment decision, the parameters entering into the investment evaluation and methods of their evaluation. In its practical part, the thesis initially presents the analysis of the external environment and inner potential of the company performed at first. Subsequently the investment project including its input parameters is introduced and an evaluation of the investment on the basis of defined methods is performed. The conclusion of the practical part is devoted to the sensitivity analysis and overall assessment of the investment plan.
618

Seleção de provedores de serviços logísticos utilizando o método de decisão multicritério ahp (analytic hierarchy process): estudo de caso no setor de cargas expressas / Logistics service providers selection by a multi-criteria decision-making method AHP (analytic hierarchy process): case study in a cargo sector expressed

Oliveira, Julio Cezar de 29 February 2016 (has links)
Submitted by Nadir Basilio (nadirsb@uninove.br) on 2016-07-01T14:42:02Z No. of bitstreams: 1 Julio Cezar De Oliveira.pdf: 1235519 bytes, checksum: 7e63ce47300a84dec3bc01d87650f12f (MD5) / Made available in DSpace on 2016-07-01T14:42:02Z (GMT). No. of bitstreams: 1 Julio Cezar De Oliveira.pdf: 1235519 bytes, checksum: 7e63ce47300a84dec3bc01d87650f12f (MD5) Previous issue date: 2016-02-29 / Outsourcing of logistics activities in the Brazil has been growing, allowing companies to direct efforts towards to their core activities and to obtain strategic gains due to the know-how of specialist companies and the possibility of reducing costs with the assets of the contracted company. Thus, tools that aid in the proper selection of suppliers can be important for the company to reach its goals. In this context, the purpose of this study is to apply the Analytic Hierarchy Process (AHP) in the evaluation process and selection of a logistics services providers (LSP) for the courier delivery services company, analyzing qualitative and quantitative criteria that express the real needs of the parties, whose aim is to improve the indicators in terms of quality and customer satisfaction. The results indicated that the information technology, responsiveness and quality of management are the most relevant criteria for the contractor because of the need of preserving the enterprise reliability front of your customers and to remain competitive in the courier delivery services area. The results also showed that the criteria and method used could contribute for classification of LSP suitable for the service in terms of deadline, demand and traceability required for operational success. A sensitivity analysis was also carried out to assess the robustness of the decision. Finally, the proposed model proved to be a good alternative to support the decision on the selection of logistics providers for express charge, since the analysis of qualitative and quantitative criteria adhering to organizational practice, can lead to choosing companies that can meet the quality requirements of the sector. / A terceirização das atividades logísticas no Brasil vem crescendo, permitindo as empresas a direcionar os esforços no sentido de suas atividades principais e obter ganhos estratégicos devido ao know-how de empresas especializadas e a possibilidade de reduzir os custos com os ativos da empresa contratada. Desta forma, ferramentas que auxiliem na seleção adequada de fornecedores, pode ser importante para que a empresa atinja seus objetivos. Nesse contexto, o objetivo deste estudo é investigar o uso do método de decisão multicritério Analytic Hierarchy Process (AHP) para a avaliação e seleção de provedores de serviços logísticos (PSLs) para empresas do segmento de cargas expressas analisando critérios qualitativos e quantitativos que expressam as reais necessidades das partes envolvidas, cujo intuito é melhorar os indicadores em termo de qualidade, prazo e satisfação dos clientes. Os resultados demonstraram que a tecnologia da informação, responsividade e a gestão da qualidade são os critérios mais relevantes para a contratante em razão da necessidade da preservação da confiabilidade da empresa frente a seus clientes e para manter-se competitiva no segmento de cargas expressas. Constatou-se que os critérios utilizados e o método contribuíram para a classificação de PSLs adequados para o atendimento em termos de prazo, demanda e rastreabilidade exigidos para o sucesso operacional. Uma análise de sensibilidade também foi desenvolvida para avaliar a robustez da decisão. O modelo proposto mostrou ser uma boa alternativa para apoio a decisão na seleção de fornecedores logísticos para carga expressa, uma vez que a análise de critérios qualitativos e quantitativos aderentes à prática organizacional, pode levar a escolha de empresas que possam atender as exigências de qualidade do setor.
619

Análises de sensibilidade aplicadas à modelagem de problemas de fluxo em meios porosos e estabilidade de taludes para quantificação de incertezas /

Assis, Higor Biondo de January 2019 (has links)
Orientador: Caio Gorla Nogueira / Resumo: Este trabalho apresenta um conjunto de técnicas estatísticas básicas aplicadas à modelagem de problemas de fluxo em meios porosos fraturados e de estabilidade de taludes, com o objetivo de identificar as variáveis explicativas mais influentes sobre a variabilidade das variáveis resposta. Diferentes planejamentos de experimentos foram utilizados para possibilitar a construção de metamodelos polinomiais representativos dos fenômenos estudados. Uma modificação do planejamento do tipo Box-Behnken é apresentada e foi proposta pelo autor para analisar problemas que envolvem elevado número de variáveis explicativas (e.g. 30). Os metamodelos, obtidos via método dos mínimos quadrados, são também chamados de superfícies de resposta ou modelos de regressão e são indispensáveis à verificação da sensibilidade das variáveis explicativas. O conjunto de técnicas mostrou- se muito eficaz na identificação das variáveis explicativas que provocaram efeitos mais significativos sobre a variável resposta. Evidenciou-se também, por meio dos exemplos de estabilidade de taludes tratados, a possibilidade de se quantificar incertezas com o uso de metamodelos suficientemente adequados, uma opção que pode ser bastante útil no processo de quantificação de incertezas de problemas que não possuem soluções analíticas simples. / Abstract: This paper presents a set of basic statistical techniques applied to the modeling of flow problems in fractured porous and slope stability media, aiming to identify the most influential explanatory variables on the response variables variability. Different designs of experiments were used to enable the construction of polynomial metamodels representative of the studied phenomena. A Box-Behnken type design modification is presented and was proposed by the author to analyze problems involving high number of explanatory variables (e.g. 30). The metamodels, obtained by the least squares method, are also called response surfaces or regression models and are indispensable for verifying the sensitivity of the explanatory variables. The set of techniques was very effective in identifying the explanatory variables that had the most significant effects on the response variable. It was also evidenced, through the examples of stability of treated slopes, the possibility of quantifying uncertainties using sufficiently adequate metamodels, an option that can be very useful in the process of quantifying uncertainty of problems that do not have simple analytical solutions. / Mestre
620

Global sensitivity analysis on vibro-acoustic composite materials with parametric dependency / L'analyse de sensibilité globale sur matériaux composites vibroacoustiques avec la dépendance paramétrique

Chai, Wenqi 30 November 2018 (has links)
Avec le développement rapide des modèles mathématiques et des outils de simulation, le besoin des processus de quantification des incertitudes a été bien augmenté. L'incertitude paramétrique et la groupe des nombreux décisions sont aujourd’hui les deux barrières principales dans la résolution des grandes problèmes systématiques.Capable de proportionner l'incertitude de la sortie sur celle des entrées, l’Analyse de Sensibilité Globale (GSA) est une solution fiable pour la quantification de l’incertitude. Parmi plusieurs algorithmes de GSA, Fourier Amplitude Sensitivity Analysis (FAST) est l’un des choix les plus populaires des chercheurs. Basé sur ANOVA-HDMR (ANalysis Of VAriance - High Dimensional Model Representation), il est solide en mathématique est efficace en calcul.Malheureusement, la décomposition unique d’ANOVA-HDMR se dépend sur l’indépendance des entrées. À cause de cela, il y a pas mal de cas industriels qui ne peut pas se traiter par FAST, particulièrement pour ceux qui donnent uniquement les échantillons mais sans lois de distribution. Sous cette demande, deux méthode extensifs de FAST avec design de corrélation sont proposées et étudiées dans la recherche. Parmi les deux méthodes, FAST-c s’est basé sur les distributions et FAST-orig s’est basé sur les échantillons.Comme applications et validations, multiples problèmes vibroacoustiques se sont traités dans la recherche. Les matériaux acoustiques avec soustructures, sont des candidats parfaits pour tester FAST-c et FAST-orig. Deux application sont présentées dans la première partie de la thèse, après l’état de l’arts. Les modèles choisis sont matérial poroélastique et structures composite sandwich, dont les propriétés mécaniques sont tous fortement influencées par les paramètres géométriques microscopique ou mesoscopique. D’avoir la méthode de FAST originale comparée avec les deux nouvelles, on trouve bien plus d’information sur la performance vibroacoustique de ces matériaux.Déjà répondu à la demande de GSA sur les modèles avecs les variables dépendantes, la deuxième partie de la thèse contient plus de recherches reliées avec FAST. D’abord FAST est pris en comparaison avec Random Forest, une algorithme bien connu de data-mining. Leurs erreurs potentiels et la possibilité de fonctioner ensemble sont discutés. Et dans les chapitres suivies, plus d’application de FAST sont présentées. Les méthodes sont appliquées sous plusieurs différente conditions. Une modèle de structure périodique qui contient des corrélation parmi les unités nous a en plus forcé à développer une nouvelle FAST-pe méthode. Dans ces applications, les designs des processus préliminaires et les stratégies d’échantillonages sont des essences à présenter. / With rapid development of mathematical models and simulation tools, the need of uncertainty quantification process has grown higher than ever before. Parametric uncertainties and overall decision stacks are nowadays the two main barriers in solving large scale systematic problem.Global Sensitivity Analysis (GSA) is one reliable solution for uncertainty quantification which is capable to assess the uncertainty of model output on its inputs’. Among several GSA algorithms, Fourier Amplitude Sensitivity Test (FAST) is one of the most popular choices of researchers. Based on ANOVA-HDMR (ANalysis Of VAriance - High Dimensional Model Representation), it is both mathematically solid and computationally efficient.One unfortunate fact is that the uniqueness of ANOVA-HDMR relies on the independency of input variables. It makes FAST unable to treat many industrial cases especially for those with only datasets but not distribution functions to be found. To answer the needs, two extended FAST methods with correlation design are proposed and further studied in this research. Among them FAST-c is distribution-based and FAST-orig is data-based.As a frame of validation and application, a number of vibroacoustic problems are dealt with in this research. Vibroacoustic materials with substructures, are perfect test candidates for FAST-c and FAST-orig. Two application cases are presented in the first part of this thesis, following the literature review. The models chosen here are poroelastic material and sandwich composite structures, both having their mechanical properties hugely influenced by their microscopic and mesoscopic geometric parameters. Getting the original FAST method compared to the two with correlation design, many different features on materials’ vibroacoustic performance are latter discovered.Having got an answer for GSA on models with dependent variables, the second part of this thesis contains more extended researches related to FAST. It is taken into comparison with Random Forest, a well-known data-mining algorithm. The potential error of both algorithms are analyzed and the possibility of joint application is discussed. In the following chapters, more applications of FAST-series methods are reported. They are applied under various conditions where another improved version named FAST-pe is developed to treat a model of periodic structures with correlation among each units. Upon these FAST application cases, the design of preliminary process and the sampling strategies is the core part to be introduced.

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