Dissertations / Theses: 'Trend and cycle decomposition'

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Boone, Laurence. "An assessment of trend extraction techniques : application to time series decomposition of business cycle and endogenous technical progress." Thesis, London Business School (University of London), 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.295884.

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Dinavahi, Chandra Rodger C. A. "Path and cycle decompositions." Auburn, Ala, 2008. http://repo.lib.auburn.edu/EtdRoot/2008/SUMMER/Mathematics_and_Statistics/Dissertation/Dinavahi_Venkatasai_39.pdf.

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Deng, Cheng. "Time Series Decomposition Using Singular Spectrum Analysis." Digital Commons @ East Tennessee State University, 2014. https://dc.etsu.edu/etd/2352.

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Singular Spectrum Analysis (SSA) is a method for decomposing and forecasting time series that recently has had major developments but it is not yet routinely included in introductory time series courses. An international conference on the topic was held in Beijing in 2012. The basic SSA method decomposes a time series into trend, seasonal component and noise. However there are other more advanced extensions and applications of the method such as change-point detection or the treatment of multivariate time series. The purpose of this work is to understand the basic SSA method through its application to the monthly average sea temperature in a point of the coast of South America, near where “EI Ni˜no” phenomenon originates, and to artificial time series simulated using harmonic functions. The output of the basic SSA method is then compared with that of other decomposition methods such as classic seasonal decomposition, X-11 decomposition using moving averages and seasonal decomposition by Loess (STL) that are included in some time series courses.

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Furlaneto, Dennis Carnelossi. "An analysis of ensemble empirical mode decomposition applied to trend prediction on financial time series." reponame:Repositório Institucional da UFPR, 2017. http://hdl.handle.net/1884/49137.

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Orientador : Luiz Eduardo S. Oliveira
Coorientador : David Menotti
Dissertação (mestrado) - Universidade Federal do Paraná, Setor de Ciências Exatas, Programa de Pós-Graduação em Informática. Defesa: Curitiba, 20/07/2017
Inclui referências : f. 63-72
Resumo: As séries temporais financeiras são notoriamente difíceis de analisar e prever dada sua natureza não estacionária e altamente oscilatória. Nesta tese, a eficácia da técnica de decomposição não-paramétrica Ensemble Empirical Mode Decomposition (EEMD) é avaliada como uma técnica de extração de característica de séries temporais provenientes de índices de mercado e taxas de câmbio, características estas usadas na classificação, juntamente com diferentes modelos de aprendizado de máquina, de tendências de curto prazo. Os resultados obtidos em dois datasets de dados financeiros distintos sugerem que os resultados promissores relatados na literatura foram obtidos com a adição, inadvertida, de lookahead bias (viés) proveniente da aplicação desta técnica como parte do pré-processamento das séries temporais. Em contraste com as conclusões encontradas na literatura, nossos resultados indicam que a aplicação do EEMD com o objetivo de gerar uma melhor representação dos dados financeiração, por si só, não é suficiente para melhorar substancialmente a precisão e retorno cumulativo obtidos por modelos preditivos em comparação aos resultados obtidos com a utilização de series temporais de mudanças percentuais. Palavras-chave: Predição de Tendencias, Aprendizado de Máquina, Séries Temporais Financeiras.
Abstract: Financial time series are notoriously difficult to analyse and predict, given their nonstationary, highly oscillatory nature. In this thesis, the effectiveness of the Ensemble Empirical Mode Decomposition (EEMD) is evaluated at generating a representation for market indexes and exchange rates that improves short-term trend prediction for these financial instruments. The results obtained in two different financial datasets suggest that the promising results reported using EEMD on financial time series in other studies were obtained by inadvertently adding look-ahead bias to the testing protocol via pre-processing the entire series with EEMD, which do affect the predictive results. In contrast to conclusions found in the literature, our results indicate that the application of EEMD with the objective of generating a better representation for financial time series is not sufficient, by itself, to substantially improve the accuracy and cumulative return obtained by the same models using the raw data. Keywords: Trend Prediction, Machine Learning, Financial Time Series.

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Joly, François-Xavier. "Tree diversity and litter decomposition in European forests." Thesis, Montpellier, 2015. http://www.theses.fr/2015MONTS215.

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Les écosystèmes forestiers jouent un rôle clé en régulant des cycles du carbone (C) et des nutriments et l’érosion en cours de la biodiversité peut affecter ces fonctions écosystémiques. Ces deux dernières décennies, un effort de recherche important a cherché à comprendre comment la biodiversité affecte la productivité primaire. Le processus inverse de minéralisation du C pendant la décomposition de la matière organique est en revanche beaucoup moins étudié. Dans cette thèse, j’ai cherché à démêler les différents mécanismes par lesquels la diversité des arbres et de leurs litières foliaires affecte la décomposition des litières dans les écosystèmes forestiers d’Europe, à travers trois approches.En utilisant un réseau de placettes forestières contenant des gradients de diversité dans six types de forêts à travers l’Europe, j’ai étudié les effets de la diversité des arbres sur la décomposition de la litière via (i) des modifications de l’environnement de décomposition et (ii) les conséquences directes de la diversité des litières foliaires, avec deux expériences en sachets de litière. A travers tous les sites, alors que la richesse spécifique des arbres a eu un effet limité, la fermeture de la canopée a positivement affecté la décomposition par une modification potentielle des conditions microclimatiques. De plus, les traits moyens de qualité physique et chimique de la chute de litière et la dissimilarité de traits entre les litières d’espèces différentes ont influencé les communautés de décomposeurs permettant dans une certaine mesure de prédire la décomposition de substrats standards. Une fois ces effets pris en compte, la qualité des litières en décomposition a eu un impact supplémentaire mais relativement plus faible sur la décomposition. Ces résultats suggèrent que les effets indirects de la diversité des arbres sur la modification des conditions microenvironnementales sont plus importants pour la décomposition que les effets directs de la qualité intrinsèque des litières en décomposition.J’ai ensuite exploré le rôle des composés solubles lessivés à partir de litière d’espèces différentes sur les processus microbiens du sol par une expérience en microcosmes. Les lessivats de litière d’arbres décidus étaient qualitativement et quantitativement différents de ceux des litières de conifères et ont induit une respiration microbienne du sol plus importante. Le mélange de lessivats des différentes espèces a donné lieu à des effets non-additifs sur les processus microbiens du sol, associés à la dissimilarité de stochiométrie des lessivats. Le lessivage étant un processus dominant pendant la phase initiale de décomposition, l’identité et la diversité des lessivats peut contribuer au contrôle du recyclage du C et des nutriments.Par une troisième approche, mon but a été de mieux comprendre les mécanismes qui sous-tendent les forts effets observées des détritivores du sol sur la décomposition des litières et les effets de diversité. J’ai cherché à comprendre si la transformation de litière en fèces par le détritivores Glomeris marginata stimulait les décomposeurs microbiens, et si cette stimulation dépendait de la qualité de la litière ingérée. L’activité microbienne était stimulée pour les fèces issues de litières récalcitrantes, mais pas pour les fèces issus de litières de meilleure qualité initiale. Ainsi, les conséquences de la transformation de litière en fèces de macroarthropodes pour les décomposeurs microbiens dépend de l’espèce de litières et peut contribuer aux effets de diversité des litières.Les données collectées durant cette thèse montre que la diversité fonctionnelle des arbres peut affecter la décomposition des litières à travers plusieurs mécanismes à différentes étapes de la décomposition. Du fait de cette complexité, les conséquences des changements de diversité pour le cycle du C et des nutriments dans les forêts d’Europe peuvent être importantes, mais sont actuellement difficiles à prédire et à généraliser
Forest ecosystems play a key role in regulating the global carbon (C) and nutrient cycles, and the ongoing erosion of biodiversity is susceptible to modify these ecosystem functions. Over the past two decades, a strong research effort was put into the understanding of how changing biodiversity impacts primary productivity. The reverse process of respiratory C loss during organic matter breakdown however, remained much less studied. In this PhD thesis, I aimed at teasing apart the different mechanisms of how tree and associated leaf litter diversity may affect litter decomposition in European forest ecosystems using three distinct approaches.First, using a network of forest plots with tree diversity gradients in six major forest types across Europe, I studied the effects of tree diversity on litter decomposition through (i) modifications of the decomposition environment and (ii) the direct consequences of leaf litter diversity, with two litterbag experiments. Across all sites, while tree species richness had only a limited effect, forest canopy closure affected decomposition positively by potentially improving microclimatic conditions. In addition, mean chemical and physical quality traits of the litterfall, and trait dissimilarity in leaf litter from different species influenced decomposer communities in a way that decomposition of the common substrates was predictable to a reasonable degree. Once these effects were accounted for, the quality of decomposing litter showed an additional, but comparatively small impact. Collectively, these results suggest that the indirect effects of tree diversity on decomposition through microenvironmental controls are more important than the direct effects of the inherent quality of decomposing litter.With a second approach using microcosms under controlled-conditions, I aimed at assessing the role of soluble compounds leached from decomposing litter of different species for microbial-driven soil processes. Leachates from litter of broadleaved deciduous species differed in composition and quantity and induced stronger soil microbial respiration than those from litter of coniferous species. When the species-specific leachates were mixed, I observed non-additive mixing effects on soil microbial processes associated to the dissimilarity in leachate stoichiometry. Since leaching is the dominant process during the initial stage of decomposition, litter leachate identity and diversity may significantly contribute to the control of carbon and nutrient cycling.Finally, in a third approach my goal was to better understand the underlying mechanisms of the observed strong effects of soil detritivores on litter decomposition and diversity effects. I investigated whether the transformation of litter into feces by the detritivore Glomeris marginata stimulated microbial decomposers, and whether this stimulation depended on the quality of the ingested litter. Microbial activity was stimulated in feces derived from recalcitrant litter, but not in feces derived from litter of higher initial quality. In conclusion, the consequences of litter transformation into macroarthropod feces for microbial decomposers is litter species-specific which may further contribute to litter diversity effects.The data collected during my PhD thesis shows that the functional diversity of trees can affect litter decomposition through various mechanisms during different stages of decomposition. As a result of this complexity, the consequences of changes in biodiversity for the carbon and nutrient cycles in European forests can be substantial, but are presently difficult to predict and to generalize

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Wilson, Connor Walter. "Ammonia recovery from municipal wastewater through a struvite formation-thermal decomposition cycle." Thesis, University of British Columbia, 2013. http://hdl.handle.net/2429/45114.

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Russell, Bernard. "The trend to standardization : product development in the British motor cycle industry 1896-1916." Thesis, City University London, 1985. http://openaccess.city.ac.uk/14789/.

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The thesis is a historical study of the first twenty years of the British motor cycle industry in terms of the development of its product. The main theoretical issue is standardization, not in its usual sense as a forma l activity aimed at the setting up of standards, but as a trend the effect of which is for products to become more and more alike across the industry as a whole. Standardization in this sense is to a large extent an unintended consequence of the wish on the part of producers to design products which operate more efficiently, which can be produced more cheaply, and which have the widest possible appeal in the marketplace; and of the preference, on the part of the majority of consumers, for products which are familiar and of known reputation and performance, as against those which are new and untried. The trend to standardization is analysed into its main components , functional efficiency, production efficiency, and marketing efficiency, and these are used as the basis of a number of propositions which make it possible to consider in more depth the development of the product during the three phases of industry development : experimental, developmental, and standardization . The more substantive chapters of the thesis are organized around three main themes, the development of the industry as a whole, and the development of the product from a technical point of view, and from a consumer point of view. The main conclusion is that the development of its product into a standard form--one on which newcomers to the industry can base their own products and which consumers can recognise as reliable and worthy of purchase-is the most critical stage in the development and consolidation of a new industry.

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Bailey, Gwendolyn Anne. "Inside the Cycle: Understanding and Overcoming Decomposition of Key Intermediates in Olefin Metathesis." Thesis, Université d'Ottawa / University of Ottawa, 2018. http://hdl.handle.net/10393/37501.

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Ru-catalyzed olefin metathesis is an exceptionally powerful, versatile methodology for the assembly of carbon–carbon bonds. The N-heterocyclic carbene (NHC)-stabilized, “second-generation” Ru catalysts have enabled groundbreaking recent advances, ranging from the RCM assembly of cyclic peptides as hepatitis C virus therapeutics, to the elaboration of renewable seed oils and phenylpropanoids into value-added products and chemicals. However, key limitations arise from facile catalyst decomposition. Despite a plethora of studies on the synthesis of new catalysts, and on the decomposition processes accessible to the precatalyst and resting-state species, the underlying principles that govern decomposition of the active intermediates have been surprisingly little examined. One important reason for this is their incredible reactivity: the four-coordinate methylidene intermediate RuCl2(H2IMes)(=CH2) is too short-lived to be observed, while the metallacyclobutane (MCB) intermediate RuCl2(H2IMes)(2-C3H6) can only be observed below –40 °C. This makes them extremely challenging, but also fascinating targets for study. Understanding the underlying chemistry that dictates their reactivity and decomposition is essential for informed catalyst and process redesign, and is thus of fundamental interest, but also considerable practical importance. This thesis work thus aims at understanding the decomposition of active intermediates relevant to the highly-active, second-generation class of catalysts. Emphasis is placed on examining a variety of metathesis contexts, as well as providing solutions. Treated first are the decomposition pathways that arise during metathesis of electron-deficient olefins, a frontier area in organic synthesis, and in the utilization of renewable resources. An unexpected correlation is revealed between rapid catalyst decomposition, and the presence of a stabilizing PCy3 ligand in the standard catalyst for this reaction. The nucleophilic phosphine ligand is shown to attack an acrylate olefin, forming enolates that function as potent Brønsted bases. Literature evidence suggests that such strong bases are innocuous towards the precatalyst, pointing towards a key role for the active intermediates in Brønsted base-induced catalyst decomposition. Precisely which intermediate is involved, as well as the site of deprotonation, is elucidated next. Prior to this work, the NHC ligand was widely believed to be the target for attack. However, through labelling experiments, analysis of the Ru and organic byproducts, and computational studies, deprotonation is shown to occur at the MCB ring. Moreover, MCB deprotonation is revealed to be unexpectedly general, and not contingent on the presence of either an exceptionally strong base, or an electron-deficient substrate. This understanding is key, given recent reports from pharma highlighting the adverse impact of base contaminants, as well as current interest in metathesis of amine-containing substrates. Next examined are the intrinsic decomposition pathways operative for the MCB and four-coordinate methylidene. Prior to this work, the only reported pathway for decomposition of these two species involved beta-elimination of the MCB ring as propene. However, beta-elimination is shown to play an unexpectedly minor role in catalyst decomposition: less than 40% propenes are observed, even under conditions expected to favour MCB elimination. Bimolecular coupling of the methylidene, with loss of the methylidene moiety as ethylene, is proposed to account for the difference. Thus, transiently-stabilized adducts RuCl2(H2IMes)(=CH2)(L)n (L = o-dianiline or pyridine) are synthesized at temperatures down to –120 °C. On warming, these adducts lose Ln and rapidly decompose via bimolecular coupling, with loss of the methylidene moiety as ethylene. These experiments provide the first unambiguous evidence for bimolecular coupling in the important "second-generation" Ru systems, nearly two decades after which this pathway was dismissed in leading papers and reviews. The last two sections focus on solutions. First, a powerful, straightforward solution to the “enolate problem” is developed, whereby the acrylate enolates are quenched and sequestered via reaction with a polyphenol resin. Then, methods for preventing catalyst decomposition during matrix-assisted laser desorption / ionization mass spectrometry (MALDI-MS) are developed, via elucidation of the instrumental and experimental factors that promote successful analysis. As one of the only MS methods capable of affording insight into neutral metal complexes and catalysts, MALDI has unique potential to enable routine analysis of catalyst speciation and decomposition in situ, under real catalytic conditions, for a wide range of catalytic reactions. Collectively, the findings in this thesis offer a much more complete understanding of the fundamental pathways accessible to the important, highly-active metathesis intermediates, and offer strategies likely to inform practice in both academic and industrial settings. This understanding is key to harnessing the full potential of metathesis methodologies.

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Coughlin, Kathleen T. "Stratospheric and tropospheric signals extracted using the empirical mode decomposition method /." Thesis, Connect to this title online; UW restricted, 2003. http://hdl.handle.net/1773/6781.

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Cao, Yujun. "Sensibilité d'un écoulement de rouleau compressé et des variations cycle à cycle associées à des paramètres de remplissage moteur." Thesis, Chasseneuil-du-Poitou, Ecole nationale supérieure de mécanique et d'aérotechnique, 2014. http://www.theses.fr/2014ESMA0020/document.

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Ce travail concerne l’étude expérimentale de la sensibilité de l’écoulement du moteur et de ses variations cycle à cycle (VCC) à trois variations des conditions aux limitesliée à l’optimisation du remplissage moteur. Dans la configuration standard, l’écoulement tridimensionnel de rouleau (« tumble ») est décrit pendant les phases d’admission et de compression.Un phasage plus précoce de la loi de levée d’admission augmente le débit de masse aux soupapes et amplifie les fluctuations dès le début de l’admission. L’intensité du rouleau est beaucoup plus faible à phase mi-compression. L’énergie fluctuante au point mort haut est plus faible. Une course rallongée du moteur conduit, en fin de compression, à un basculement de l’écoulement moyen et à une évolution très différente des vitesses fluctuantes,due au confinement différent vue par l’aérodynamique du moteur. Enfin, la modification des conduits d’admission entraîne une variation de l’intensité et une structuration fondamentalement différente de l’écoulement. En outre, pour décrire le transfert vers la turbulence,deux méthodologies de classification des structures de l’écoulement en groupe par corrélation spatiale, puis par « clustering » sont adaptées. L’analyse statistique du contenu des différents groupes et des transitions entre groupes permet de montrer que les VCC sont associées à différentes trajectoires dans l’espace des groupes. Des statistiques conditionnelles sont calculées pour analyser les données de chaque groupe et permettent de définir une décomposition triple. Ces caractérisations plus précises des VCC sont très générales et applicables à des grandes bases de données expérimentales ou numériques
This experimental work concerns a sensitivity study of the in-cylinder flow in aspark-ignition engine and of the cycle to cycle variations (CCV) by comparing three variationsof boundary conditions related to the optimisation of air filling conditions. In the reference case, the three dimensional tumble flow is characterized during the intake and compression phases. A earlier intake cam phase increases the mass flow rate at inlet valves and amplifiesthe fluctuations immediately after the start of intake phase. The tumble ratio is much lowerat mid-compression phase. The fluctuating energy at top dead center is reduced. A longerengine stroke leads, at the end of compression phase, to a shift of mean flow and to a verydistinct evolution of the fluctuating velocity, due to the different confinement from the pointof view of the engine internal flow. Finally, the modification of intake duct design changes theflow intensity and reorganizes in depth the flow structure. Moreover, to describe the transfer into turbulence, two methodologies of classification in groups of flow structures, by spatial correlation then by clustering, are proposed. A phase-averaged analysis of the statistics of group content and inter-group transitions shows that CCV can be associated with different sets of trajectories during the second half of the compression phase. The conditional statistics are computed to analyse the data in each group, which leads to a triple decomposition. It is important to point out that this more accurate evaluation of CCV is applicable to very large sets of experimental or numerical data

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Jiang, Rui. "Estimating and Reducing Road Carbon Emissions through Hybrid Life Cycle Assessment and Decomposition Analysis." Thesis, Curtin University, 2021. http://hdl.handle.net/20.500.11937/86297.

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This research aims to estimate and reduce carbon emissions from use and maintenance and rehabilitation (M&R) of roads. An extensive literature review was conducted on related studies. A hybrid LCA approach was proposed to accurately estimate such emissions, which was embedded into a multi-attribute decision making framework to help road agencies select optimal network-level pavement maintenance plans. In addition, driving factors for vehicle-related emissions during 2009-2017 in Australia were investigated to establish emissions reduction strategies.

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Antonakakis, Nikolaos, and Harald Badinger. "International Business Cycle Spillovers since the 1870s." Taylor & Francis, 2014. http://dx.doi.org/10.1080/00036846.2014.937040.

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This article considers the evolution of international business cycle interdependencies among 27 developed and developing countries since the beginning of 1870s, utilising the generalized vector autoregressive (VAR)-based spillover index of Diebold and Yilmaz (2012), which allows the construction of a time-varying measure of business cycle spillovers. We find that, on average, 65% of the forecast error variance of the 27 countries' business cycle shocks is due to international spillovers. However, the magnitude of international business cycle spillovers varies considerably over time. There is a clear increasing trend since the end of World War II and until the middle 1980s. After that, international business cycle interdependencies declined during the period that was dubbed the Great Moderation, and stabilized around the beginning of the twenty-first century. During the Great Recession of 2008-2009, international business cycle spillovers increased to unprecedented levels. Finally, developed countries are consistently ranked as net transmitters of cyclical shocks to developing counties throughout the sample. (authors' abstract)

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Abdoulwahab, Mohamed Toihir. "Étude de la variabilité et la tendance de l'ozone stratosphérique au-dessus des tropiques et subtropiques sud." Thesis, La Réunion, 2016. http://www.theses.fr/2016LARE0012/document.

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L'ozone joue un rôle primordial sur l'équilibre photochimique de l'atmosphère et participe au processus d'équilibrage radiatif entre les deux hémisphères (Mecke, 1931). Dans la troposphère, l'ozone détermine la capacité oxydante de la majorité des gaz et absorbe continuellement dans la stratosphère les radiations ultraviolettes nocives (McMicheal et al., 2003). D'où l'intérêt de surveiller la variation de la couche d'ozone de façon régulière. Il a été constaté au début des années 80, une diminution inquiétante et progressive de la colonne totale de l'ozone dûe aux émissions anthropiques des substances riches en chlore, brome et fluor. Ce constat a conduit au Protocole de Montréal en 1987 dont l'objectif est de mettre en place une politique internationale visant à réduire les émissions des substances appauvrissant l'ozone. Dix ans après la signature du dit Protocole, la concentration de ces substances commence à diminuer dans l'atmosphère et la prospection d'un recouvrement progressif de la couche d'ozone demeure aujourd'hui un sujet d'actualité (UNEP/PNUE, 2009 ; OMM, 2010 et 2014). Les besoins d'aujourd'hui sont de réaliser des mesures continues et fiables de l'ozone dont leurs exploitation dans des méthodes et/ ou des modèles bien adaptés à la problématique aideront la communauté à suivre l'évolution de l'ozone et d'estimer les tendances à long terme. Dans ce travail, une variété de produits d'ozone issue de différents instruments a été combinée pour construire des bases des données fiables et homogènes afin d'étudier sa variabilité et d'estimer la tendance de l'ozone dans les régions tropicale et subtropicale sud. L'application de ces bases de données sur les ondelettes a permis d'identifier les principaux forçages qui contrôlent la variabilité de l'ozone et la période de retour associée à chaque forçage. Il s'agit des variations saisonnières du climat, les oscillations quasi-biennales, les oscillations australes El-Niño et l'activité solaire dont le cycle moyen est évalué à 11ans. Le comportement et l'influence de chacun de ces paramètres sur la viabilité de l'ozone sont étudiés. Cette étude est faite en s'appuyant sur des méthodes statistiques et sur le modèle Trend-Run. Avec ce modèle, la part de contribution et la réponse de chaque paramètre sur la variabilité de l'ozone sont quantifiées. Les résultats sur les tendances montrent une augmentation de la couche d'ozone avec un taux variant entre 0 et 2.78% par décade (selon la région et le site) sur la période 1998-2012. Cette amélioration est bien observée au-dessus de 22km, surtout aux subtropiques par rapport à la région équatoriale
Ozone plays an important role on photochemical equilibrium of atmosphere and participate on radiative balance process between hemispheres (Mecke, 1931). In the troposphere, ozone determines the oxidizing capacity of major species and absorbs continuously in the stratosphere the harmful ultraviolet radiation (McMichael et al, 2003). Based on the above facts, it is important to monitor ozone continuously with consistency and accuracy. Global total column ozone (TCO) has depleted gradually since 1980 with an increase of chlorofluorocarbon concentrations in the stratosphere due to anthropogenic activities. In 1987, the Montreal protocol was formulated in order to regulate the emissions of substances that deplete ozone. Concentrations of these substances are observed to decrease ten years after the Montreal protocol. Thus we have been expecting an increase in ozone by now (UNEP/PNUE, 2009; WMO, 2010 and 2014). The current needs are to achieve consistent and reliable measurements in which their exploitation on adapted methods/models can help scientists to follow the ozone evolution and to estimate long term ozone trend. In this work, a variety of ozone products from different instruments was combined in order to create reliable and homogenous dataset to study the ozone variability and trend over the southern tropics and subtropics. The dataset application on wavelets method allowed to identify the dynamic parameters that control ozone variability and their periodicities. These include seasonal variations of climate, the quasi-biennial oscillations, the El-Niño Southern Oscillation and the 11-years solar cycle. The behavior of each parameter and its influence on ozone variability were analysed based on statistical method and the Trend-Run model. The contribution and response of each variable on ozone variability were quantified from the model. The obtained trends results exhibit an increase of total ozone from 1998 to 2012 with a rate varying between 0 and 2.78% par decade (depending of the site and region). The ozone increase was observed mainly above 22 km and it is more important over the subtropical region with respect to equatorial zone

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Abs, Elsa. "Eco-evolutionary modeling of soil microbial decomposition in a warming climate." Thesis, Sorbonne Paris Cité, 2019. https://theses.md.univ-paris-diderot.fr/ABS_Elsa_2_complete_20190108.pdf.

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L'une des principales sources d'incertitude des projections climatiques globales tient à l’activité microbienne des sols : dans quelle mesure le réchauffement de la planète entraînera-t-il une augmentation des concentrations de CO2 dans l'atmosphère du fait d’une décomposition accrue de la matière organique par les communautés microbiennes des sols ? Mieux évaluer, voire réduire, cette incertitude requiert le développement de modèles mathématiques mécanistes reliant la décomposition à la dynamique des communautés microbiennes et l’intégration de ces modèles dans les simulations globales. Les modèles mathématiques de décomposition de la matière organique du sol représentent explicitement le compartiment microbien et sont donc à même de mettre en relation biomasse microbienne, production d’enzymes de dégradation de la matière organique, stocks de carbone du sol. Formulés dans le contexte du changement climatique, ces modèles se sont concentrés sur les mécanismes physiologiques et écologiques des réponses microbiennes à l’augmentation de la température, ignorant les effets possibles de l'adaptation évolutive. Ma thèse vise à combler cette lacune, en évaluant l'hypothèse selon laquelle l'adaptation évolutive microbienne au réchauffement peut avoir un impact significatif sur le cycle global du carbone. Après avoir passé en revue des modèles de décomposition microbienne mécanistes et non évolutifs, je construis un modèle stochastique spatialement explicite et éco-évolutif, basé sur des processus microscopiques des cellules et des molécules extracellulaires. J'utilise une approximation du modèle (spatialement implicite, déterministe) pour étudier la réponse éco-évolutive au réchauffement d'un système microbe-enzyme du sol, dans trois scénarios possibles d’influence de la température sur l'activité microbienne. En l'absence d'évolution microbienne, le réchauffement entraîne une perte de carbone dans le sol (une accélération du changement climatique) dans tous les scénarios. L'adaptation évolutive microbienne aggrave généralement la perte de carbone du sol dans les écosystèmes froids et peut aggraver, amortir ou même inverser la perte de carbone (et donc augmenter la séquestration du carbone) dans les écosystèmes chauds. En contraignant le modèle avec les observations de cinq biomes distincts je montre que l'aggravation évolutive de la perte de carbone du sol est l’issue la plus probable. Enfin, en intégrant mon modèle éco-évolutif dans une projection globale des stocks de carbone du sol à l'échelle de la Terre, je confirme la prévision d'une aggravation mondiale significative de la perte de carbone dans le sol due à l'évolution microbienne. Les sols dormants, dans lesquels l'activité microbienne est très faible, jouent un rôle particulier dans la dynamique éco-évolutive à long terme du carbone du sol global, car dans ces régions, l'effet négatif de l'évolution sur les stocks de carbone du sol ne se manifesterait pas avant la sortie de la dormance microbienne et pourrait de fait s’en trouvé différé de plusieurs décennies. En conclusion, mes travaux constituent un premier pas vers des modèles de prédiction de la dynamique éco-évolutive du cycle du carbone. Ils ouvrent la voie à un programme de recherche qui testerait de manière empirique les prédictions des modèles sur le rôle des mécanismes évolutifs dans différents types d’écosystèmes terrestres, en exploitant les archives de plus en plus riches de données métagénomiques des sols pour quantifier les variations des fonctions métaboliques microbiennes et leurs réponses à la sélection
One major source of uncertainty in global climate predictions is the extent to which global warming will increase atmospheric CO2 concentrations through enhanced microbial decomposition of soil organic matter. There is therefore a critical need for models that mechanistically link decomposition to the dynamics of microbial communities, and integration of these mechanistic models in global projection models of the Earth system. Mathematical models of soil microbial decomposition models have recently been introduced to predict soil C stocks and heterotrophic soil respiration, especially in the context of climate change. Thus far, models focused on physiological and ecological mechanisms of microbial responses, leaving the role of evolutionary adaptation poorly understood. My thesis addresses this gap and evaluates the hypothesis that microbial evolutionary adaptation to warming can have a significant impact on the global carbon cycle. After reviewing mechanistic, non- evolutionary microbial models of decomposition, I construct an eco-evolutionary spatially explicit, stochastic model, scaling up from microscopic processes acting at the level of cells and extracellular molecules. I use an approximated version of the model (spatially implicit, deterministic) to investigate the eco-evolutionary response of a soil microbe-enzyme system to warming, under three possible scenarios for the influence of temperature on microbial activity. In the absence of microbial evolution, warming results in soil carbon loss to the atmosphere (an amplification of climate change) in all scenarios. Microbial evolutionary adaptation generally aggravates soil carbon loss in cold ecosystems, and may aggravate, buffer or even reverse carbon loss in warm ecosystems. Constraining the model with observations from five contrasting biomes reveals evolutionary aggravation of soil carbon loss to be the most likely outcome. Earth-scale projections of carbon stocks that integrate my eco-evolutionary model support the prediction of a significant global aggravation of soil C loss due to microbial evolution. Dormant soils, in which microbial activity is very low, play a special role in the long-term eco-evolutionary dynamics of global soil carbon, since in these regions, the negative effect of evolution on soil carbon stocks may not kick in until the microbial community shifts from dormant to active, and may thus be delayed by decades. Overall, my work is a first step toward predictive modeling of eco- evolutionary dynamics of carbon cycling; it also lays the ground for a broad future research program that will empirically test model predictions about the role of evolutionary mechanisms in different systems across the globe, by leveraging the growing global archive of soil metagenomics data to quantify variations in microbial metabolic functions and their response to selection. Mots clés en français (10 max) : changement climatique, cycle du carbone, décomposition, projections globales, évolution microbienne, dynamiques adaptatives, rétroaction sol-climat, évolution de la coopération, modèles individu-centrés.Mots clés en anglais : climate change, carbon cycle, decomposition, global predictions, microbial evolution, adaptive dynamics, soil-climate feedbacks, evolution of cooperation, individual-based models

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Kürschner, Dierk, and Christoph Jacobi. "Long-term behaviour of E-region nighttime LF reflection heights: long-term trend, solar cycle, and the QBO." Wissenschaftliche Mitteilungen des Leipziger Instituts für Meteorologie ; 30 = Meteorologische Arbeiten aus Leipzig ; 8 (2003), S. 127-135, 2003. https://ul.qucosa.de/id/qucosa%3A15242.

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The nighttime reflection height of low-frequency (LF) radio waves at oblique incidence is measured at Collm Observatory using 1.8 kHz sideband phase comparisons between the sky wave and the ground wave of a commercial 177 kHz LF transmitter. The measurements have been carried out continuously since September 1982, now allowing the analysis of trends and regular variations of the reflection height. In the time series is found a) a long-term negative trend and b) a solar cycle dependence, both confirming earlier measurements and theoretical estimations. Moreover, a significant oscillation of quasi-biennial period is visible in LF reflection heights, indicating a reaction of the midlatitude mesosphere/lower thermosphere region on the equatorial quasi biennial oscillation.
Am Observatorium Collm der Universität Leipzig werden die nächtlichen Reflexionshöhen von Langwellen auf 177 kHz unter Verwendung von Seitenbandinformationen in einem kleinen Bereich um 1.8 kHz gemessen. Die Messungen werden seit September 1982 durchgeführt und erlauben nunmehr Analysen von Langzeittrends und regulären Variationen der unteren Ionosphäre. Bei der Untersuchung der Zeitreihen fallen die folgenden Zusammenhänge auf: a)es existiert ein negativer Trend, welcher mit der Abkühlung der Stratosphäre in Zusammenhang steht, b) die Reflexionshöhe weist eine Modulation mit dem 11-Jährigen Sonnenfleckenzyklus auf und c) es ist eine deutliche quasi-zweijährige Schwingung sichtbar, die auf eine Kopplung der Mesosphäre und unteren Thermosphäre mit der äquatorialen Stratosphäre hinweist.

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Vondrová, Dagmar. "Evaluace adopce IT trendů v bankovnictví." Master's thesis, Vysoká škola ekonomická v Praze, 2016. http://www.nusl.cz/ntk/nusl-203904.

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This research work examines trends that affect information technology in the Czech retail banking. The main objective is the evaluation of IT trends adoption in retail banking. To achieve this goal, interviews with IT professionals in the Czech retail banks and IT consultants in the field of banking were taken. Specific objectives were identification and consolidation of IT trends in the banking sector through the analysis of relevant sources identified in the research. Consolidation is using the methodology mentioned in book Trend Management Toolkit by author Kjear. Analysis of IT trends in banking aimed to describe the identified trends and their position on the Hype Cycle curve. First part of work consist of introduction, goals, assumptions, limitations and expected benefits, specifying the current state by conducting research. The theoretical part describes the key bank characteristics and trends influencing retail bank sector. Based on an analysis of selected reports work identifies key IT trends in banking and their consolidation. The practical part discuss the results of in-depth interviews conducted with people with long lasting experience in IT in banks. Usefulness of the results can be seen in the identification of current IT trends in banking and the creation of an analytical procedure for finding the most significant trends of all currently mentioned. Furthermore, in evaluating the state of IT adoption trends, which is currently expected by retail banks and considering possible further steps in this area. Leading to decisions about future investments or to strategy review.

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Xia, Yan. "Packings and Coverings of Complete Graphs with a Hole with the 4-Cycle with a Pendant Edge." Digital Commons @ East Tennessee State University, 2013. https://dc.etsu.edu/etd/1173.

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In this thesis, we consider packings and coverings of various complete graphs with the 4-cycle with a pendant edge. We consider both restricted and unrestricted coverings. Necessary and sufficient conditions are given for such structures for (1) complete graphs Kv, (2) complete bipartite graphs Km,n, and (3) complete graphs with a hole K(v,w).

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Barth, Johannes A. C. "Effects of water balance, decomposition of organic matter and photosynthesis on the chemistry and the carbon cycle in the Upper St.Lawrence River (Canada)." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape17/PQDD_0025/NQ36764.pdf.

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SCHAEFER, Holger Christian. "Production and decomposition dynamics of extraradical hyphae of arbuscular mycorrhizal fungi in warm-temperate forests of Chamaecyparis obtusa (hinoki cypress)." Kyoto University, 2019. http://hdl.handle.net/2433/243322.

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Lin, TsungPo. "An adaptive modeling and simulation environment for combined-cycle data reconciliation and degradation estimation." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/24819.

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Thesis (Ph.D.)--Aerospace Engineering, Georgia Institute of Technology, 2008.
Committee Chair: Dimitri Mavris; Committee Member: Erwing Calleros; Committee Member: Hongmei Chen; Committee Member: Mark Waters; Committee Member: Vitali Volovoi.

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Coulis, Mathieu. "Effets des changements climatiques sur l’activité des organismes du sol et la décomposition des litières en milieu méditerranéen." Thesis, Montpellier 2, 2013. http://www.theses.fr/2013MON20252.

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La disponibilité en eau est le principal facteur limitant le fonctionnement des écosystèmes méditerranéens. Des sècheresses plus marquées ou plus fréquentes pourraient avoir d'importantes répercussions sur l'activité et la diversité de la faune du sol qui régule la décomposition des litières et le cycle des nutriments. Dans cette thèse j'ai étudié expérimentalement les interactions entre une modification des apports en eau et l'impact de la macrofaune détritivore sur les processus de décomposition en conditions méditerranéennes. Dans une première partie, j'ai étudié l'effet d'une espèce de détritivore très abondante localement, Ommatoiuus sabulosus, sur la décomposition des litières d'arbustes de garrigue. Une expérience d'un mois en microcosmes a permis d'étudier ses effets directs (via la consommation de litière) et indirects (via l'activité microbienne dans ses fèces) sur la perte de masse des litières et les communautés microbiennes à deux niveaux d'humidité contrastés. Dans une autre expérience d'un an sur le terrain, la mise en place de sachets de litières et de fèces à deux profondeurs dans un sol de garrigue a permis d'étudier les effets d'Ommatoiulus à plus long terme. Les principaux résultats montrent que sa consommation de litière est moins affectée par la sècheresse que la décomposition microbienne, mais que, à court terme, Ommatoiulus ne stimule pas la minéralisation de la matière organique, quelles que soient les conditions d'humidité. En revanche, à plus long terme, Ommatoiulus peut accélérer la décomposition de certaines litières comme le chêne kermès, puisque des fèces issues de cette litière déposées à la surface du sol pendant un an perdent plus de masse que de la litière non-consommée. Cette stimulation semble liée à un lessivage plus important des composés organiques solubles dans les fèces et ne se produit qu'à la surface du sol. En profondeur, où l'humidité du sol est plus favorable à la décomposition, la perte de masse des fèces augmente. Ce résultat suggère qu'en facilitant l'enfouissement de la matière organique dans le sol, les détritivores peuvent accélérer la décomposition.Dans une seconde partie, j'ai cherché à évaluer l'importance de la diversité fonctionnelle des litières et des détritivores pour le processus de décomposition. Grâce à une approche basée sur les traits, des assemblages d'espèces représentant un fort gradient de dissimilarité fonctionnelle mais ayant une richesse spécifique constante, ont été créés pour étudier la réponse de la relation diversité-fonction à la sécheresse. Les résultats de cette expérience menée à l'Ecotron de Montpellier, montrent que la dissimilarité fonctionnelle des litières et des détritivores explique jusqu'à 20% de la variation observée dans plusieurs processus clefs du fonctionnement du sol, tels que la perte de masse des litières et le lessivage du carbone et de l'azote dans le sol superficiel. Toutefois, les effets de l'identité des espèces présentes aux deux niveaux trophiques restent plus importants que ceux de la dissimilarité fonctionnelle. Bien que la sécheresse influence fortement les processus étudiés, les relations diversité-fonction ne sont pas modifiées par un changement de la disponibilité en eau. Cependant, les assemblages d'espèces les plus performants en conditions d'humidité favorables sont aussi les plus fortement affectés par la sécheresse, ce qui suggère qu'il existe un compromis entre l'efficacité des organismes du sol et leur capacité à résister à une perturbation
Water availability is a major limiting factor for the functioning of Mediterranean ecosystems. More pronounced drought could severely impact soil fauna activity and diversity that could in turn affect litter decomposition and nutrient cycling. In my PhD thesis I investigated experimentally the interactions between changing water availability and detritivorous macrofauna on decomposition and associated processes in a “garrigue”, a typical Mediterranean woody shrub dominated ecosystem.In the first part of my thesis, I studied the impact of Ommatoiulus sabulosus, an abundant diplopod species in garrigue ecosystems, on shrub litter decomposition. During a one month experiment, I studied the direct (litter consumption) and indirect (microbial activity in feces) effects of this detritivore on litter mass loss and microbial communities under two contrasted moisture levels. In a different experiment, I placed litterbags filled with litter or feces in the field at the soil surface or at 5cm soil depth during one year in order to study the long term impact of Ommatoiulus on decomposition. A key result was that detritivores maintain litter consumption in dry conditions when microbial driven decomposition drastically dropped. However, this detritivore effect do not lead to an overall increased organic matter mineralization irrespective of moisture conditions, at least in the short term. In contrast, under field conditions and over a longer time period, Ommatoiulus increases decomposition of certain species such as Quercus coccifera, since feces from this species decomposes faster than un-ingested litter after one year at the soil surface. This stimulation is likely due to a higher leaching of soluble compound in feces. Moreover, in depth feces decomposition increases relative to that of intact leaf litter, possibly indicating that more favorable soil humidity is more favorable to decomposition. Collectively, my results suggest that detritivores can strongly increase decomposition by transforming leaf litter into feces of different organic matter quality, and by facilitating the transfer of organic matter into the soil.In the second part, I evaluated the importance of functional dissimilarity of leaf litter and detritivores on decomposition processes. Using a trait based approach, species assemblages were constructed in order to obtain a gradient of functional dissimilarity of both, leaf litter and detritivore communities, while keeping species numbers constant. The different communities were kept under controlled conditions at the European Ecotron in Montpellier to study the effect of changing functional dissimilarity on process rates at two different moisture conditions. I found that detritivore and litter functional dissimilarity explain up to 20 % of the observed variation for several key soil processes including litter mass loss and the leaching of dissolved organic carbon and nitrogen from top soil. However, effects of species identity at both trophic levels have a larger impact on process rates than functional dissimilarity. In general, drought strongly affects soil processes but does not alter the diversity-function relationship. Species assemblages resulting in highest process rates at favorable moisture level are also the most negatively affected by drought, suggesting a tradeoff between the efficiency of soil organisms and their ability to resist perturbation

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Altinalmazis, kondylis Andreas. "Tree diversity effects on root production, decomposition and nutrient cycling under global change." Thesis, Bordeaux, 2021. http://www.theses.fr/2021BORD0067.

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L'hypothèse de l'assurance prévoit que les forêts composées de mélanges d'espèces d'arbres pourraient mieux résister aux conditions environnementales stressantes que les forêts composées d'une seule espèce d'arbre. La majorité des travaux antérieurs ont testé cette hypothèse en se focalisant sur la productivité et les variables de réponse associées sans prendre en compte les processus souterrains. L’objectif principal de ma thèse était d’étudier l’effet de la diversité des espèces d’arbres sur les processus souterrains impliqués dans la décomposition des racines à travers des gradients climatiques. J'ai émis l'hypothèse que le mélange d'espèces ayant des systèmes racinaires contrastés entraînerait une faible compétition souterraine, et se traduirait par la production de plus biomasse de racines fines. En outre, j'ai émis l'hypothèse que les racines ayant des caractéristiques chimiques et morphologiques contrastées dans les peuplements mixtes se décomposent plus rapidement. Dans des conditions de stress hydrique, j'ai émis l'hypothèse d'une décomposition plus lente mais d’une atténuation des mélanges d'arbres sur la décomposition en raison de l'amélioration des conditions micro-environnementales. Pour tester ces hypothèses, j'ai examiné la variation des caractéristiques fonctionnelles des racines et leurs conséquences sur les flux de C, N et P à l'échelle de l'écosystème à travers l’étude de : 1) la ségrégation verticale des racines et la biomasse des racines fines, 2) la dynamique des racines fines et les flux de nutriments associés et 3) la décomposition des racines fines et des feuilles mortes. Dans ce cadre, trois deux expériences de terrain ont été réalisé, l'une avec une expérience de plantation d'arbres de 10 ans avec du bouleau et du pin près de Bordeaux (expérience ORPHEE), la seconde le long d'un gradient latitudinal de forêts de hêtres matures dans les Alpes françaises (expérience BIOPROFOR).Les résultats obtenus montrent que les racines de bouleaux et de pins présentaient une distribution verticale similaire et une biomasse souterraine similaire de racines dans les mélanges d'arbres par rapport aux monocultures, contrairement à ma première hypothèse. Cependant, l'attribution plus importante du pin mais pas du bouleau à la croissance des racines dans les horizons du sol supérieur dans des conditions moins limitatives en eau suggère des conditions localement favorables qui peuvent conduire à une compétition asymétrique à la profondeur du sol. De plus, la production et la décomposition des racines fines étaient similaires dans les mélanges et dans les monocultures, en contradiction avec ma deuxième hypothèse. Il est intéressant de noter que les racines de bouleau, mais pas les racines de pin, ont libéré du P pendant leur décomposition, ce qui suggère un rôle important du bouleau dans le cycle du P et pour la nutrition en P des arbres sur ces sols sableux limités en P. Conformément à ma troisième hypothèse, j'ai observé une décomposition plus lente de la litière de feuilles et des racines fines en réponse à une sécheresse estivale prolongée, tout au long du gradient latitudinal dans les Alpes. Cependant, cette décomposition plus lente sous la sécheresse n'a pas été atténuée dans les peuplements forestiers à essences mixtes par rapport aux peuplements à essences uniques. Il est intéressant de noter qu’il y a une libération nette d'azote dans les racines fines en décomposition mais pas dans la litière de feuilles en décomposition, ce qui suggère un rôle distinct des racines fines dans le cycle de l'azote. En conclusion, j'ai constaté que le mélange des espèces d'arbres n'atténue pas les effets négatifs du changement climatique. Cette thèse démontre que la promotion de mélanges peut toujours être bénéfique pour au moins une des espèces d'arbres mélangées, par l'ajout d'espèces, car une espèce d'arbre peut en faciliter la nutrition minérale d’une autre par des flux souterrains de N et de P
The insurance hypothesis predicts that forests with tree species mixtures may resist better to stressful environmental conditions than forests composed of only one tree species. Most of the currently available literature tested this hypothesis for aboveground productivity and its related response variables, but less is known about belowground processes. In my PhD thesis, I studied the drivers of belowground productivity and decomposition across climatic gradients and how they are affected by tree mixtures. I hypothesized that mixing of tree species with contrasting rooting patterns and fine root morphologies, would result in a release of competitive pressure belowground, and translate into higher fine root standing biomass and increased fine root productivity. Moreover, I hypothesized that roots with contrasting chemical and morphological characteristics in mixed stands would decompose faster, which may be particularly important under nutrient-limited conditions. Under water-limiting conditions, such as during extreme summer drought, I hypothesized overall slower decomposition but an attenuating effect of tree mixtures on decomposition due to improved micro-environmental conditions, in particular for leaves, since roots decompose in a more buffered soil environment. To test these hypotheses I examined the variation in tree root functional traits (across- and within-species), and its consequences for fluxes of C, N and P at the ecosystem scale. I addressed three main objectives and associated research questions to quantify the interactive effect of tree mixtures and climate on: 1) vertical root segregation and fine root standing biomass, 2) fine root dynamics and their associated nutrient fluxes and 3) fine root- and leaf litter decomposition. I could benefit from two different field experiments for my work, one with a 10-year-old tree-plantation experiment with birch and pine close to Bordeaux (ORPHEE experiment), the second along a latitudinal gradient of mature beech forests in the French Alps (BIOPROFOR experiment).I observed that roots from the birch and pine tree-plantation showed similar vertical distribution and similar belowground root standing biomass in tree mixtures compared to monocultures, contrary to my first hypothesis. However, the greater allocation of pine but not of birch to root growth within the top soil horizons under less water-limiting conditions suggests locally favourable conditions that may lead to soil depth-specific asymmetric competition. In the same experiment, fine root production and decomposition were similar in mixtures and in monocultures, in contradiction with my second hypothesis. Moreover, I did not observe any interactive effects of tree mixtures with stand density or water availability. Interestingly though, birch roots, but not pine roots released P during root decomposition, which suggests an important role of birch in the P-cycle and for P nutrition of trees on these P-limited sandy soils. In line with my third hypothesis, I observed a slower decomposition of leaf litter and fine roots in response to reinforced and prolonged summer drought, irrespective of the position along the latitudinal gradient in the Alps. However, this slower decomposition under drought was not attenuated in forest stands with mixed tree species compared to single species stands. Compared to leaf litter, fine roots decomposed slower and released less C. Interestingly, I found a net N release in decomposing fine roots but not in decomposing leaf litter, which suggests a distinct role of fine roots in the N cycle. In conclusion, I found that mixing tree species did not attenuate negative effects of climate change. However, this thesis demonstrates that promoting mixtures can still be beneficial for at least one of the admixed tree species, through species addition (i.e., complementing one tree species with another tree species), as one tree species may facilitate another via belowground fluxes of N and P

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van, der Ploeg Frederick, and Armon Rezai. "Cumulative emissions, unburnable fossil fuel, and the optimal carbon tax." Elsevier, 2017. http://dx.doi.org/10.1016/j.techfore.2016.10.016.

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A stylised analytical framework is used to show how the global carbon tax and the amount of untapped fossil fuel can be calculated from a simple rule given estimates of society's rate of time impatience and intergenerational inequality aversion, the extraction cost technology, the rate of technical progress in renewable energy and the future trend rate of economic growth. The predictions of the simple framework are tested in a calibrated numerical and more complex version of the integrated assessment model (IAM). This IAM makes use of the Oxford carbon cycle of Allen et al. (2009), which differs from DICE, FUND and PAGE in that cumulative emissions are the key driving force of changes in temperature. We highlight the importance of the speed and direction of technological change for the energy transition and how time impatience, intergenerational inequality aversion and expected trend growth affect the time paths of the optimal global carbon tax and the optimal amount of fossil fuel reserves to leave untapped. We also compare these with the adverse global warming trajectories that occur if no policy actions are taken.

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Abdulhay, Enas. "Une nouvelle méthode non-invasive d'estimation cycle à cycle du volume d'éjection cardiaque dans le signal de plethysmographie respiratoire par inductance : algorithme de "double décomposition empirique"." Université Joseph Fourier (Grenoble ; 1971-2015), 2009. http://www.theses.fr/2009GRE10220.

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L'objectif principal qui guide les développements en traitement du signal de cette thèse est la mise au point d'un outil qui s'inscrit dans une démarche de physiologie intégrative où, à chaque échelle, le modèle des signaux peut être différent On cherche ici à restreindre le jeu d'hypothèses a priori à un ensemble de règles physiologiques qui régissent les interactions entre functions physiologiques en l'absence d'hypothèses fonnelles et: mathématiques sur les signaux. Nous avons appliqué cette démarche au problème de la détection des ondes cardiaques et: de l' estimation cycle à cycle du volume d'éjection dans le signal RIP (Respiratoty Inductive Plethysmography). L'approche par décomposition empirique se prête particulièrement à notre logique. Nous proposons ici la première version d'un algorithme basé sur une double décomposition empirique du signal RIP. La méthode choisie et: les outils correspondants ont été testés sur deux types de données, d'une part des signaux simulés, d'autre part des signaux enregistrés sur volontaires sains. Notre objectif est donc aussi de mettre au point un modèle cardiorespiratoire pouvant servir d'outil de simulation des signaux ventilatoires, cardiaques et: de RIP avec la simulation de l'effet de chaque système sur l'autre. Les résultats montrent que la méthode proposée est adaptée à l'analyse du signal RIP et: à l' estimation du volume d'éjection
The main objective that guides the signal processing approaches ofthis thesis is the development of a tool that oould be part of an integrative physiology approach where, at each scale, the model of signais may be different We seek here the restriction of asstnnptions a priori to a set: of rules goveming the physiological interactions between physiological functions in the absence of fannal and mathematical assumptions. We applied this approach to the problem of cardiac waves detection and estimation of cycle-to-cycle stroke volume in the RIP signal (Respiratory Inductive Plethysmography). The empirical decomposition approach seems to be particularly adapted to our logic. We propose here the first version of an algorithm based on RIP double decomposition. The method and its COITeSpül1ding tools have been tested on two types of data, simulated signais and real signais recorded at healthy volunteers. Our aim is also therefore to develop a cardio-respiratory model that can serve as a tool for ventilatory, cardiac and RIP signals simulation along with the simulation of the effect of each system on the other. The results show that the proposed method is suitable for RIP signal analysis and for stroke volume estimation

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Maillard, Morgane. "From deer abundance to soil properties : A case study in the forests of Haida Gwaii." Thesis, Montpellier, 2019. http://www.theses.fr/2019MONTG043.

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L’augmentation récente et spectaculaire de l'abondance des cerfs en Amérique du Nord et en Europe occidentale a entraîné de profonds changements dans la structure des forêts tempérées. Si ces changements sont aujourd'hui bien caractérisés, les effets de cette forte abondance sur le sol restent cependant mal compris. Les cerfs peuvent interagir avec le sol par le rejet de fèces et d’urine, le piétinement et la réduction de la quantité et de la qualité de la litière par le broutage préférentiel des plantes appétantes. Quelles sont les conséquences de ces interactions pour le sol ? Pour répondre à cette question, nous avons étudié la réponse des sols à la colonisation et à l'élimination du cerf de Sitka (Odocoileus hemionus sitkensis) dans les forêts d’Haïda Gwaii. Nous avons constaté que les cerfs ralentissaient la décomposition en réduisant la qualité de la litière. La structure de la communauté microbienne et sa capacité à décomposer le carbone était impactée par la compaction du sol dû au piétinement. Nous avons également constaté que les effets des cerfs à court et moyen termes n’avaient que peu ou pas d'effet sur le sol, remettant en question les conclusions des études actuelles basées sur de plus court terme
The past century witnessed a dramatic increase in deer abundance in North America and Western Europe that triggered profound changes in the structure of temperate forests. If these changes are today well characterised, the effects of abundant deer belowground in these forests remain unclear. Deer can interfere with the soil through waste deposition, trampling, and reduction of litter quantity and quality by preferential browsing of palatable plants. What are the consequences of these interactions for the soil? To answer this question, we studied the soil response to the colonisation and culling of Sitka black-tailed deer (Odocoileus hemionus sitkensis) in the forests of Haida Gwaii. We found that deer slowed-down litter decomposition by reducing litter quality. They also modified microbial community structure and ability in decomposing carbon via soil trampling. Most of these effects became only apparent in the long term, hence questioning the results obtained through short term studies

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Rezai, Armon, and der Ploeg Frederick Van. "Cumulative Emissions, Unburnable Fossil Fuel and the Optimal Carbon Tax." WU Vienna University of Economics and Business, 2016. http://epub.wu.ac.at/4795/1/EcolEcon_WorkingPaper_2016_8.pdf.

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A new IAM is used to calculate the optimal tradeoff between, on the one hand,locking up fossil fuel and curbing global warming, and, on the other hand,sacrificing consumption now and in the near future. This IAM uses the Oxford carbon cycle, which differs from DICE, FUND and PAGE in that cumulative emissions are the key driving force of changes in temperature. We highlight how time impatience, intergenerational inequality aversion and expected trend growth affect the time paths of the optimal global carbon tax and the optimal amount of fossil fuel reserves to leave untapped. We also compare these with the adverse and deleterious global warming trajectories that occur if no policy actions are taken. (authors' abstract)
Series: Ecological Economic Papers

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Butcher, Daniel S. A. "Influence of asymmetric valve timing strategy on in-cylinder flow of the internal combustion engine." Thesis, Loughborough University, 2016. https://dspace.lboro.ac.uk/2134/23327.

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Variable Valve Timing (VVT) presents a powerful tool in the relentless pursuit of efficiency improvements in the internal combustion engine. As the valves have such ultimate control over the gas exchange processes, extensive research effort in this area has shown how valve event timing can be manipulated to reduce engine pumping losses, fuel consumption and engine out emissions. Pumping losses may be significantly reduced by use of throttleless strategies, making use of intake valve duration for load control, while alternative cycles such as the Miller cycle allow modification of the effective compression ratio. More recently, the value of single valve operation in part load conditions is exploited, bringing with it the concept of asymmetric valve lifts. Work in this area found the side effect of asymmetric valve operation is a significant change in the behaviour of the in-cylinder flow structures, velocities and turbulence intensity. Work presented in this thesis exploits asymmetric valve strategies to modify the in-cylinder flow conditions. The Proper Orthogonal Decomposition (POD) is a method employed in the fluids dynamics field to facilitate the separation of coherent motion structures from the turbulence. In the presented work, the application of POD to in-cylinder flow analysis is further developed by the introduction of a novel method for identifying the POD modes representative of coherent motion and those representative of the turbulence. A POD mode correlation based technique is introduced and developed, with the resulting fields showing evidence of coherence and turbulence respectively. Experimental tests are carried out using a full length optically accessible, single cylinder research engine equipped with a fully variable valve train (FVVT) to allow full control of both valve timing and lift. In-cylinder flow is measured through the use of Particle Image Velocimetry (PIV) at several crank angle timings during the intake stroke whilst the engine is operated under a range of asymmetric valve strategies. The exhaust valves and one intake valve have their respective schedules fixed, while the second intake valve schedule is adjusted to 80\%, 60\%, 40\%, 20\%, 0\% lift. The resulting PIV fields are separated into coherent motion and turbulence using the developed technique, allowing for analysis of each constituent independently. The coherent element gives insight to large scale flows, often of the order of magnitude of the cylinder. These structures not only give a clear indication of the overall motion and allow assessment of flow characteristics such as swirl and tumble ratio, but the variation in the spatial location of these structures provides additional insight to the cyclic to cycle variation (CCV) of the flow, which would not otherwise be possible due to the inclusion of the turbulent data. Similarly, with the cyclic variation removed from the turbulent velocity field, a true account of the fluctuating velocity, u' and derived values such as the Turbulent Kinetic Energy (TKE) may be gained. Results show how manipulation of a one intake valve timing can influence both the large scale motions and the turbulence intensity. By the reduction of lift, the swirl ratio is increased almost linearly as the typical counter-rotating vortex pair becomes asymmetric, before a single vortex structure is observed in the lowest lift cases. A switching mechanism between the two is identified and found to be responsible for increased levels of CCV. With the reduction in lift, TKE is observed not only to increase, but change the spatial distribution of turbulence. Of course, the reduction in valve lift comes with the penalty of a reduced valve curtain area. However, it was identified both in literature and throughout this study that the reduction in lift did not negatively influence the engine breathing as the same trapped mass was achieved under all cases with no adjustment of manifold pressure. While literature shows both bulk motion and turbulence are key in liquid fuel break-up during the intake stroke, the mixing effects under port-injected natural gas were investigated experimentally using Laser Induced Fluorescence (LIF). The valve strategy was found to have no significant effect on the mixture distribution at the time of spark.

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Wang, Yi. "Default risk in equity returns an industrial and cross-industrial study /." Cleveland, Ohio : Cleveland State University, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=csu1251906476.

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Thesis (Ph.D.)--Cleveland State University, 2009.
Abstract. Title from PDF t.p. (viewed on Sept. 8, 2009). Includes bibliographical references (p. 149-154). Available online via the OhioLINK ETD Center and also available in print.

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Justham, Timothy. "Cyclic variation in the flow field behaviour within a direct injection spark ignition engine : a high speed digital particle image velocimetry study." Thesis, Loughborough University, 2010. https://dspace.lboro.ac.uk/2134/6551.

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Currently environmental concerns are driving internal combustion engine manufacturers to seek greater fuel efficiency, more refinement and lower emissions. Cyclic variation is a known obstacle to achieving the greatest potential against these goals and therefore an understanding of how to reduce these is sought. It is widely accepted that cyclic variation in in-cylinder flow motions is a key contributor to overall cyclic variation and therefore the characterisation of factors affecting these is an important step in the process of achieving a better understanding and ultimately control of cyclic variation. This thesis reports the development of a novel optical engine research facility in which high speed digital particle image velocimetry (HSDPIV) has been applied to the study of flow field behaviour within a direct injection spark ignition (DISI) engine. This study investigates the spatial and temporal development of flow structures over and within many engine cycles. Flow field PIV measurements have been captured with a high spatial resolution and temporal frequencies up to 5 kHz from a number of measurement locations at a large range of crank angles. The major contributions from this work have included the use of the novel measurement technique to investigate spatial and temporal flow field development in the intake runner, valve jet, in-cylinder tumble and swirl planes and the pent roof. The gathered data have been used to investigate cycle by cycle variations in both high and low frequency flow structures. Major findings of this work have included the observation of highly varying flow fields throughout the engine cycle. Frequency analysis of these flows has allowed the low frequency bulk motions and higher frequency turbulent components to be studied. The low frequency flow field components are shown to create varying flow field interactions within the cylinder that also affect the manner in which the flow develops over the course of the cycle. The intensity of the turbulence fluctuations, u , has been calculated based upon the high frequency components within the flow and variations within this are shown to correlate with pressure related combustion parameters.

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Húsková, Michaela. "Pokročilá analýza signálů z laboratoře chůze." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2019. http://www.nusl.cz/ntk/nusl-400991.

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The aim of the thesis is a realization of advanced analysis of signals from gait laboratory. The introductory part deals with the gait cycle and its relation to the joints kinematic is discussed. Additionally, the work is focused on the description of the gait laboratory and the definition of the indexes in order to quantify patient´s overall gait in kinematic analysis. In the practical part, kinematic data analysis was implemented in the MATLAB environment and the results of healthy individuals and patients with cerebral palsy were compared. Kinematic analysis included peak detection in specific kinematic variables. In the last part a graphical user interface for visualization was implemented.

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Khatiwada, Dilip. "Assessing the sustainability of bioethanol production in different development contexts: A systems approach." Doctoral thesis, KTH, Energi och klimatstudier, ECS, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-125618.

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The continuous depletion of fossil fuel reserves, the global agenda on climate change and threats to energy security have led to increased global interest in the exploration, production and utilisation of bioenergy and biofuels. Access to modern bioenergy carriers derived from the efficient conversion of locally available biomass resources is indispensable for economic growth, rural development and sustainable development in developing countries. Deployment of bioenergy/biofuels technologies has significantly varied across the globe. The least developed countries (LDCs) and developing countries are still highly dependent on traditional biomass technologies with low conversion efficiency, which are typically associated with significant environmental and health impacts. Meanwhile, emerging economies and developed countries are progressively promoting biofuel industries and international trade. They are also engaged in making biofuels a sustainable proposition by developing sustainability criteria. The goal of this thesis is to address the sustainability of bioethanol production derived from one of the key feedstocks/energy crops: sugarcane. This will be done by analysing different development contexts and environmental constraints in terms of geopolitical situation, economic development and state-of-the-art technologies in agro-industrial development. Life cycle assessment (LCA), system studies, and techno-economic optimisation are the main methodological approaches applied in the thesis. The thesis primarily addresses three key questions for analysing the sustainability of bioethanol production. The first research question investigates the key parameters affecting the sustainability of bioethanol production and use in a low-income country using the case of Nepal. The net energy and greenhouse gas (GHG) balances are identified to be the main sustainability criteria of the sugarcane-molasses bioethanol (Paper I and II). Results of the lifecycle studies show that the production of bioethanol is energy-efficient in terms of the fossil fuel inputs required to produce the renewable fuel. Greenhouse gas (GHG) emissions from the production and combustion of ethanol are also lower than those from gasoline. The study also evaluates the socio-economic and environmental benefits of ethanol production and use in Nepal, concluding that the major sustainability indicators are in line with the goals of sustainable development (Paper III). Assessment of the biofuel (molasses-bioethanol) sustainability in Nepal is the first of its kind in low-income countries, and serves also the purpose of motivating the assessment of ethanol production potential in other LDCs, particularly in sub-Saharan Africa. The second question critically evaluates methodologies for accounting the lifecycle GHG emissions of Brazilian sugarcane ethanol in European and American regulations, depicting commonalities and differences among them (Paper IV). GHG emissions are becoming increasingly important as part of sustainability criteria in the context of the expansion of biofuel production and international trade. However, different methodologies still lead to quite different results and interpretation. To make this an operational criterion for international comparisons, it is necessary to establish unified methodological procedures for accounting GHG emissions. The thesis identifies the major issues as N2O emissions from agricultural practices, bioelectricity credits in fuel production, and modelling approaches in estimating emissions related to direct and indirect land use change (LUC & iLUC), that need to be addressed for establishing methodological coherences. The third research question investigates how the sugarcane bioethanol industry can be developed in terms of energy security and the diversification of energy sources. The case of complementarity between bioelectricity and hydropower is evaluated in the cases of Nepal and Brazil and presented in Paper V. Bioelectricity could offer a significant share of electricity supply in both countries provided that favourable political and institutional conditions are applied. Finally, in order to find the choice of technological options for the production of second generation (2G) bioethanol and/or of bioelectricity, a techno-economic optimisation study on the bulk of sugarcane bio-refineries in Brazil is carried out in Paper VI, taking into account the entire lifecycle costs, emissions, and international trade. The study shows that it is worthwhile to upgrade sugarcane bio-refineries. Energy prices, type of power generation systems, biofuel support and carbon tax, and conversion efficiencies are the major factors influencing the technological choice and potential bioethanol trade. In short, this dissertation provides insights on the sustainability of the bioethanol production/industry and its potential role in the mitigation of climate change, improved energy security and sustainable development in different country contexts, as well as methodological contributions for assessing the sustainability of biofuels production in connection with energy and climate policies.
Intresset för ökad exploatering, produktion och användning av bioenergi och biobränslen har föranletts av den kontinuerliga utmattningen av fossila bränslen, den globala agendan för att motverka klimatförändringar samt hoten mot energisäkerheten. Tillgången till moderna bioenergibärare, effektivt framställda från lokal råvara, är grundläggande för ekonomisk tillväxt, landsbygdsutveckling samt för hållbar utveckling i utvecklingsländer. Användandet av bioenergi- och biobränsleteknologi har varierat markant världen över. De minst utvecklade länderna (LDCs) samt övriga utvecklingsländer är fortfarande beroende av traditionella biomassabaserade tekniker till stor utsträckning. Dessa tekniker har låg effektivitet och är ofta sammankopplade med stora miljö- och hälsoskador. Samtidigt främjar tillväxtekonomier och utvecklingsländer biobränsleindustrin och internationell handel progressivt. Länderna arbetar även för att biobränslen ska bli ett hållbart alternativ genom att utveckla hållbarhetskriterier. Den här avhandlingens mål är att adressera hållbarheten hos bioetanolproduktion från sockerrör, en av bioetanolens nyckelråvaror. Målet kommer att nås genom analyser av industrins nationella utvecklingsmiljö samt miljö- och klimatmässiga begränsningar som härstammar från den geopolitiska situationen och den ekonomiska tillväxten i landet, samt analyser av teknologier i den agro-industriella utvecklingen. De huvudsakliga metoder som använts är livscykelanalys (LCA), systemstudier och tekno-ekonomisk optimering. Avhandlingen adresserar primärt tre nyckelfrågor för att analysera hållbarheten hos bioetanolproduktion. Den första forskningsfrågan belyser hur nyckelparametrar påverkar hållbarheten hos produktion och användning av bioetanol i låginkomstländer, med fallstudien Nepal som utgångspunkt. Nettoenergi- och växthusgasbalanser identifieras som de huvudsakliga hållbarhetskriterierna för sockerrör-melass-baserad bioetanol (Artikel I och II). Livscykelstudiernas resultat visar att produktionen av bioetanol är energieffektiv sett från den mängd fossila bränslen som produktionen av förnybart bränsle krävt. Växthusgasutsläppen från produktion och förbränning av etanol är dessutom lägre än utsläppen från bensin. Studien utvärderar de socio-ekonomiska och miljö- och klimatmässiga fördelarna med produktion och användning av etanol i Nepal. Slutsatsen är att indikatorerna för hållbarhet ligger i linje med målen för hållbar utveckling (Artikel III). Bedömningen av biobränslens (melass-baserad etanol) hållbarhet i Nepal är den första studien i sitt slag för låginkomstländer. Studien motiverar dessutom en bedömning av potentialen för etanolproduktion i andra LDCs, speciellt i de afrikanska länderna söder om Sahara. Den andra forskningsfrågan kräver en kritisk utvärdering av metoderna för hur livscykelutsläpp från brasiliansk sockerrörsetanol redovisas i europeiska och amerikanska regleringar (Artikel IV). Artikeln, som påvisar likheter och skillnader mellan regionerna, visar att växthusgasutsläpp blir en mer och mer viktig del i hur hållbarhetskriterier definieras när expansionen av biobränsleproduktion och internationell handel diskuteras. Olika metoder för redovisningen av växthusgasutsläpp leder dock till mycket olika resultat och tolkningar. Det är nödvändigt att etablera en enhetlig metod för redovisning av växthusgasutsläpp för att skapa ett kriterium som möjliggör internationella jämförelser. Avhandlingen identifierar de mest beaktansvärda problemen för att etablera en enhetlig metod: N2O-utsläpp från jordbruksprocesser, tillgodoräknande av bioelektricitet inom bränsleproduktion, samt modelleringsmetoder för att uppskatta utsläpp relaterade till direkt och indirekt landanvändning (LUC och iLUC). Den tredje forskningsfrågan utreder hur industrin för sockerrörsbioetanol kan utvecklas från ett energisäkerhetsperspektiv, med speciell hänsyn till diversifieringen av energikällor. I Artikel V presenteras hur bioelektricitetsproduktion och vattenkraft kan komplettera varandra i fallen Nepal och Brasilien. Bioelektricitet skulle kunna bidra markant till tillförseln av elektricitet i båda länderna under förutsättning att de politiska och institutionella förutsättningarna är fördelaktiga. Slutligen utförs en tekno-ekonomisk studie för att identifiera den optimala teknologin för produktion av andra generationens (2G) bioetanol och/eller bioelektricitet. Studien görs för merparten av sockerrörsbioraffinaderierna i Brasilien och utgör Artikel VI. Studien tar fullskaliga livscykelkostnader i beaktande samt utsläpp och internationell handel. Studien visar att det är värt mödan att uppgradera befintliga sockerrörsbioraffinaderier. De dominerande påverkansfaktorerna för valet av teknologi och potentialen för bioetanolhandel är energipriser, typ av kraftproduktionssystem, biobränslestöd och koldioxidskatt, samt processernas effektivitet. Kortfattat behandlar den här avhandlingen bioetanolproduktionens och bioetanolindustrins hållbarhet. Avhandlingen ger insikt i dess potentiella roll för att motverka klimatförändringar, förbättra energisäkerhet samt främja hållbar utveckling i olika nationella sammanhang. Avhandlingen bidrar dessutom med metodutveckling i hur hållbarheten av biobränsleproduktion bedöms inom ramen för energi- och klimatpolicy.

QC 20130813

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Zhu, Shaoming. "Multiscale analysis of protein functions and stochastic modelling of gene transcriptional regulatory networks." Thesis, Queensland University of Technology, 2010. https://eprints.qut.edu.au/41693/1/Shaoming_Zhu_Thesis.pdf.

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Genomic and proteomic analyses have attracted a great deal of interests in biological research in recent years. Many methods have been applied to discover useful information contained in the enormous databases of genomic sequences and amino acid sequences. The results of these investigations inspire further research in biological fields in return. These biological sequences, which may be considered as multiscale sequences, have some specific features which need further efforts to characterise using more refined methods. This project aims to study some of these biological challenges with multiscale analysis methods and stochastic modelling approach. The first part of the thesis aims to cluster some unknown proteins, and classify their families as well as their structural classes. A development in proteomic analysis is concerned with the determination of protein functions. The first step in this development is to classify proteins and predict their families. This motives us to study some unknown proteins from specific families, and to cluster them into families and structural classes. We select a large number of proteins from the same families or superfamilies, and link them to simulate some unknown large proteins from these families. We use multifractal analysis and the wavelet method to capture the characteristics of these linked proteins. The simulation results show that the method is valid for the classification of large proteins. The second part of the thesis aims to explore the relationship of proteins based on a layered comparison with their components. Many methods are based on homology of proteins because the resemblance at the protein sequence level normally indicates the similarity of functions and structures. However, some proteins may have similar functions with low sequential identity. We consider protein sequences at detail level to investigate the problem of comparison of proteins. The comparison is based on the empirical mode decomposition (EMD), and protein sequences are detected with the intrinsic mode functions. A measure of similarity is introduced with a new cross-correlation formula. The similarity results show that the EMD is useful for detection of functional relationships of proteins. The third part of the thesis aims to investigate the transcriptional regulatory network of yeast cell cycle via stochastic differential equations. As the investigation of genome-wide gene expressions has become a focus in genomic analysis, researchers have tried to understand the mechanisms of the yeast genome for many years. How cells control gene expressions still needs further investigation. We use a stochastic differential equation to model the expression profile of a target gene. We modify the model with a Gaussian membership function. For each target gene, a transcriptional rate is obtained, and the estimated transcriptional rate is also calculated with the information from five possible transcriptional regulators. Some regulators of these target genes are verified with the related references. With these results, we construct a transcriptional regulatory network for the genes from the yeast Saccharomyces cerevisiae. The construction of transcriptional regulatory network is useful for detecting more mechanisms of the yeast cell cycle.

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Matondo, Hubert. "Synthese de n-4 pyridylcarbamates a activite herbicide potentielle : etude cinetique de l'influence des solutions micellaires sur leur hydrolyse." Toulouse 3, 1987. http://www.theses.fr/1987TOU30026.

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Guittonny, Larcheveque Marie. "Valorisation d'un compost de boues urbaines en garrigue pour le reboisement : comportement des jeunes arbres d'une plantation et modifications de la dynamique de la vegetation naturelle apres amendement." Phd thesis, Université de Provence - Aix-Marseille I, 2004. http://tel.archives-ouvertes.fr/tel-00008812.

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Depuis que la Communauté européenne a interdit la mise en décharge des déchets non ultimes, la recherche de nouveaux débouchés pour les boues d'épuration devient cruciale. En région méditerranéenne, les feux récurrents et les précipitations parfois violentes favorisent l'érosion et induisent l'appauvrissement des sols. Les sols calcaires dégradés sont souvent colonisés par des formations végétales stables à Quercus coccifera, adaptées à un faible niveau de ressources, ce qui ralentit l'installation naturelle des arbres. Dans de tels milieux, un amendement organique pourrait améliorer la fertilité du sol, modifier la dynamique et les relations de dominance de la végétation, et favoriser les processus de succession et de résilience, ainsi que la reforestation. Deux expérimentations ont été menées en Provence pour étudier les effets d'apports de compost de boues d'épuration urbaines et de déchets verts sur la dynamique d'un écosystème de garrigue. Premièrement, 0, 50, et 100 t.ha-1 de compost brut ont été épandues en surface dans le biotope naturel de garrigue, et les conséquences sur le fonctionnement de l'écosystème ont été étudiées. Les compartiments sol, végétation et microorganismes de la litière ont été suivis pendant deux ans après amendement (2002-2004). Deuxièmement, nous avons incorporé au sol trois doses de compost brut (0, 20, et 40 kg.ha-1) au pied de jeunes plants d'arbres. L'évolution des propriétés édaphiques et du développement des arbres a été suivie respectivement pendant trois ans (2001-2003) et deux ans (2002-2003). L'amendement a durablement (2 ans) et efficacement amélioré la fertilité du sol. Cependant, le sol a été fortement enrichi en P et Zn, ce qui pourrait entraîner des problèmes sérieux de pollution des eaux et de toxicité sur les microorganismes. Ces deux éléments limitent l'utilisation de compost de boues dans les milieux naturels, et des amendements répétés aux doses étudiées sont inenvisageables. Dans la plantation, l'amendement a globalement favorisé le processus de reforestation en améliorant la nutrition et la croissance des plants, et surtout en augmentant leur survie en période de sécheresse. En outre, l'apport de compost en surface a généré l'apparition d'îlots fertiles dans le biotope garrigue, au sein desquels les processus de succession végétale pourraient être localement optimisés, ce qui pourrait favoriser à terme la colonisation par la strate arborée, notamment par Pinus halepensis. Par ailleurs, l'amendement augmente la diversité fonctionnelle en garrigue du fait de son effet bénéfique sur les espèces semencières, ce qui pourrait améliorer la résilience de l'écosystème après incendie. Ces effets bénéfiques du compost se produisent surtout pour les doses intermédiaires. L'utilisation de compost aux doses maximales testées devrait être abandonnée, du fait d'une dépréciation de la colonisation fongique de la litière de Quercus coccifera observée pour 100t.ha-1, et du fait d'une augmentation des risques de pollution par le P et le Zn proportionnellement au taux d'apport. Cependant, la nature calcaire du sol expérimental et la maturité élevée du compost ont limité les phénomènes d'exportation vers les eaux et la contamination des plantes par les éléments potentiellement toxiques. L'apport de compost en surface a plutôt augmenté la sensibilité des plantes à la sécheresse, alors que celle-ci a diminué lorsque le compost a été apporté en mélange au sol. Enfin, l'apport de compost en garrigue a eu des effets multiples (fertilisation, écrasement, dépôt d'une couche fertile) et a permis de mettre en évidence les stratégies spécifiques des plantes dans la gestion des nutriments et de la productivité. Ce travail montre l'importance relative des espèces végétales sur le fonctionnement de l'écosystème, identifie les espèces clef pour le recyclage des éléments, et illustre la complémentarité d'utilisation des ressources qui existe au sein de l'écosystème naturel de garrigue.

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Amine, Maria El. "Heterocycles germanies : synthese, reactivite, nouvelles voies d'acces aux especes du germanium a coordinence non usuelle." Toulouse 3, 1987. http://www.theses.fr/1987TOU30202.

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Ce travail concerne l'etude d'heterocycles germanies precurseurs d'especes du germanium tricoordine. La premiere partie est consacree a une mise au point bibliographique concernant les especes a germanium doublement lie. La deuxieme partie concerne l'etude des reactions de thermolyse, pyrolyse et photolyse de thiagermetannes-3,1 photolyse de dithiagermolannes-2,4,1 et pyrolyse de dioxydes-3,3 de thiagermetannes-3,1 qui font intervenir des intermediaires et de nouvelles especes du germanium pi lie, les sulfenes. Cette partie concerne egalement des tentatives de synthese du dimethyl-1,1 oxagermetanne-3,1. La synthese et la decomposition de nouveaux petits cycles tendus, les dioxagermetannes-1,3,2 ainsi que l'etude de la thermolyse de l'octamethylcyclotetragermoxane sont decrites dans la troisieme partie. La mise en evidence par spectroscopie photoelectronique de germanones est rapportee au quatrieme chapitre. Dans le cinquieme chapitre, sont exposees les syntheses, thermolyse et photolyse de diverses structures heterocycliques originales a 6 et 5 chainons du type dithiadigermannes-1,4,2,3 dithia-1,4 trigermolannes et dithia-1,4 tetragermannes qui sont egalement d'excellents precurseurs de germathiones et de germylenes. La derniere partie concerne l'etude des premiers phosphonates germanies cycliques a 4 et 5 chainons. Les reactions d'echange entre les phosphonates et divers chlorures metalles (m::(14)) et sc1::(2) sont decrites

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Havel, Tomáš. "Uplatnění statistických metod při zpracování dat." Master's thesis, Vysoké učení technické v Brně. Fakulta podnikatelská, 2010. http://www.nusl.cz/ntk/nusl-222576.

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This master’s thesis engages in elaborating the chosen ratio indicators of the two competing companies, elaborating time series out of these indicators and their equation. The prognosis of the future development will be determined based on these indicators and the suggestions will be formulated for eventual issues.

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Wolf, Sylvie. "Interaction des failles sismiques : modélisation mathématique et numérique de l'instabilité du glissement." Phd thesis, Université Joseph Fourier (Grenoble), 2003. http://tel.archives-ouvertes.fr/tel-00744990.

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Nous modélisons les processus de glissement instable, en tenant compte de la géométrie souvent complexe des systèmes de failles et des lois de frottement observées en laboratoire. Nous assimilons les failles à des interfaces de discontinuité dans un milieu élastique parfait, la croûte, et utilisons une loi de frottement dépendant du glissement déduite d'expériences qui montrent que la résistance du matériau diminue du seuil statique au seuil dynamique, proportionnellement au glissement.Nous proposons deux méthodes numériques. La première a pour but de simuler l'évolution temporelle spontanée d'un réseau de faille, soumis initialement à un champ de contraintes donné et auquel nous appliquons une perturbation initiale en vitesse. Elle utilise un schéma de type Newmark en temps, et une discrétisation spatiale en éléments finis avec décomposition de domaines. Elle se révèle capable de capturer efficacement les instabilités du glissement, et en particulier la phase d'initiation, qui précède la propagation de la rupture dynamique et qui se caractérise par une forme auto-similaire et une croissance exponentielle du glissement au cours du temps. Des expériences numériques montrent que l'interaction, sur des segments de faille présentant un recouvrement significatif, se manifeste par l'existence de " zones d'ombre " dans lesquelles les contraintes sont déchargées et le glissement inhibé. En cas de recouvrement important de deux segments de faille, on observe une dissymétrie des profils de glissement, correspondant à la disparition de la singularité de contraintes à l'une des pointes de faille.Le deuxième schéma numérique réalise l'analyse spectrale non linéaire du problème de l'initiation " pseudo-linearisé " autour de la position d'équilibre dans laquelle le système de failles est initialement au seuil de résistance statique. La non-linéarité du problème provient de la prise en compte des zones d'ombre dont on ne connaît pas la géométrie a priori. Cette analyse permet de trouver le mode qui porte la signature de l'initiation, c'est-à-dire la forme auto-similaire remarquée plus haut. La version statique de cette analyse modale fournit un critère de stabilité des réseaux de failles, c'est-à-dire la valeur limite du taux d'affaiblissement au-delà de laquelle un épisode de glissement donnera lieu à un évènement sismique.Nous faisons l'hypothèse que le mode non linéaire statique, qui caractérise un comportement en affaiblissement à la limite de la stabilité, peut être utilisé pour décrire le glissement cumulé à l'échelle tectonique sur un réseau de failles normales particulier en Afar, dont nous connaissons les glissements mesurés en surface. Nous montrons qu'un choix judicieux du profil d'affaiblissement " équivalent " à l'échelle tectonique permet un bon accord entre le glissement observé et le mode statique. Nous en tirons des conclusions en termes d'interaction, mais aussi depropagation et/ou branchement des segments de failles. Enfin, nous décrivons deux autres applications :l'influence de la fracturation secondaire (endommagement) sur la forme du glissement les paramètres géométriques favorables à l'apparition d'une zone de relai entre deux segments de faille se propageant l'un vers l'autre.

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Gannac, Yves. "Alliages Fe-6,5%Si élaborés par solidification rapide sous atmosphère controlée : microstructure, propriétés magnétiques et comparaison avec des alliages Fe-Si industriels." Toulouse, INSA, 1992. http://www.theses.fr/1992ISAT0015.

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La realisation d'un dispositif de solidification rapide sous atmosphere controlee permet l'elaboration de rubans fer-silicium avec un exces de silicium (6,5% masse) dont l'etat de surface est ameliore par rapport a celui de rubans trempes a l'air. Un bon controle de parametres de coulee conduit a l'elaboration de rubans de qualite et geometrie correctes et reproductibles. Les proprietes magnetiques a faible frequence (0-50 hz), placent ces alliages a un niveau legerement inferieur a celui des alliages industriels a grains orientes, mais nettement au-dessus des alliages a grains non orientes qui ont une texture voisine de celles des rubans. La chute des proprietes quand la frequence augmente n'est pas observee sur les rubans, conferant a ceux-ci des proprietes a 400 hz meilleures que celles des alliages industriels a grains orientes ou non. Pour un large domaine d'induction, des equations parametriques simples peuvent representer les courbes d'aimantation experimentales. L'etude de la decomposition en serie de fourier met en evidence divers aspects physiques qui influencent l'allure de ces courbes (mecanismes d'aimantation, courants induits)

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39

Бондар, Тетяна Вікторівна, Татьяна Викторовна Бондарь, and Tetiana Viktorivna Bondar. "Організаційно-економічний механізм забезпечення конкурентоспроможності підприємтва з урахуванням екологічного фактору." Thesis, Вид-во СумДУ, 2014. http://essuir.sumdu.edu.ua/handle/123456789/36654.

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У дисертації запропоновано теоретичну модель підприємства як відкритої системи та визначено зміст поняття «екологічно орієнтована конкурентоспроможність». Удосконалено науково-методичні підходи до оцінки екологічно орієнтованої конкурентоспроможності підприємства на основі оцінки потенціалу його конкурентоспроможності та рівня конкурентоспроможності продукції з урахуванням відверненого економічного збитку довкіллю. Розроблено організаційно-економічний механізм забезпечення екологічно орієнтованої конкурентоспроможності підприємства. При цитуванні документа, використовуйте посилання http://essuir.sumdu.edu.ua/handle/123456789/36654
В диссертационном исследовании проведены систематизация, анализ и обобщение теоретических положений и представлено авторское решение научной задачи − развитие научно-методических подходов к обеспечению экологически ориентированной конкурентоспособности промышленных предприятий, что позволяет планировать и реализовывать этапы жизненного цикла предприятия и таким образом учитывать экологический фактор в процессе хозяйствования. В диссертации предложена теоретическая модель предприятия как открытой системы с позиций категорий пространства и времени. Системная модель предприятия учитывает его закономерное состояние, исходя из проектной модели, потенциал предприятия и его жизненный цикл. В работе определены виды потенциала конкурентоспособности предприятия − конкурентоформирующий, конкурентообеспечивающий и конкурентоподдерживающий, которые создаются на протяжении жизненного цикла предприятия, начиная из продуцирования идеи его создания. Определено содержание понятия «экологически ориентированная конкурентоспособность» с позиций системных принципов развития. Развиты теоретические принципы обеспечения конкурентоспособности с учетом экологического фактора. Разработаны критерии и нормативы экологически ориентированной конкурентоспособности для её оценки, а также для разработки и обоснования стратегии обеспечения экологически ориентированной конкурентоспособности предприятия. Усовершенствованы научно-методические подходы к оценке экологически ориентированной конкурентоспособности на основе оценки потенциала конкурентоспособности предприятия и уровня конкурентоспособности его продукции с учетом предотвращенного экономического ущерба окружающей среде в результате разработки, производства и реализации продукции. Представлен алгоритм разработки стратегии обеспечения конкурентоспособности, основанный на выявлении и определении внутренней (структурной) тенденции развития предприятия, которая имманентно ему присуща, а также построении вектора развития в соответствии с этапами жизненного цикла предприятия на основе определения ожидаемых величин потенциала развития, потенциала самоорганизации, потенциала реализации внешних связей предприятия, а также уровня конкурентоспособности его продукции в динамике. На основе системного подхода к обеспечению экологически ориентированной конкурентоспособности предприятия в работе разработан организационно-экономический механизм ее достижения, который направлен на повышение и реализацию потенциала конкурентоспособности предприятия в течение всего жизненного цикла предприятия, учитывая его проектные свойства, рыночные позиции, вектор развития и предполагает использование соответствующих организационно-экономических инструментов управления экологически ориентированной конкурентоспособности для каждого этапа жизненного цикла предприятия. При цитировании документа, используйте ссылку http://essuir.sumdu.edu.ua/handle/123456789/36654
The theoretical model of the enterprise as an open system from the standpoint of the categories has been proposed and as well the essence of «environmentally oriented competitiveness» has been defined in the thesis. The scientific and methodical approaches to assessing the environmentally oriented competitiveness of the enterprise based on the assessment of competitiveness potential and the product competitiveness taking into account preventing economic damage to the environment have been improved. Organizational and economic mechanism of environmentally oriented competitiveness of the enterprise has been developed. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/36654

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40

Debleds, François. "Complexation d'électrophiles aromatiques par des bases hétérocycliques ambidentes : structure et réactivité d'adduits carbones et azotes pyrroliques indoliques et imidazoliques." Paris 6, 1987. http://www.theses.fr/1987PA066330.

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Structure et formation des complexes de Meisenheimer du trinitro-1,3,5 benzène avec divers indoles, pyrroles, imidazoles ; étude cinétique de la décomposition de ces complexes. Etude cinétique de la protonation du kryptopyrrole en solution aqueuse.

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41

Yi-Tsen-Kuo and 郭羿岑. "Growth-Cycle Decomposition Multi-GenerationalDiffusion Model." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/26332121802274505739.

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碩士
國立成功大學
工業與資訊管理學系碩博士班
98
Sales forecasting is one of the important events to every company. Changing in customers’ requirements and environment are related to procurement operations, inventory management, production scheduling and other enterprise activities. Accurate demand forecasts can achieve lower inventory costs, reduce manpower requirements, improve much customer service quality and business competitiveness. In this study, there are two different methods to forecast sales of DRAM industry. The first is Growth-Cycle Decomposition Multi-Generational Diffusion Model that is to forecast multi-generational DRAM sales. Because DRAM industry is easily affected by business cycle and price, General Multi-Generational Diffusion Model do not consider the business cycle variables. In this study, I use both price and GDP variables, wondering whether these variables are meaningful to the whole model after these two variables added. Norton and Bass (1987) model are extensively cited by many researchers. This study is also compared with Norton and Bass (1987) model. The second method is the grey theory,used to forecast global DRAM sales. Grey Theory method can easily deal with nonlinear problems, less data, small samples of forecasting. This study uses annual sales data of DRAM industry over the decade. Construct an appropriate sales forecasting model to improve the efficiency of enterprise management and decision-making as a reference for managers to improve the competitiveness of management. In this study, use the global DRAM as an empirical subject. Results show that Grey Theory for DRAM has good accuracy, and using only a small number of historical data set can predict well. Moreover, Growth-Cycle Decomposition Multi-Generational Diffusion Model joins price and GDP variables together which also does contribute to the whole model. Key

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Wang, Yu Chih, and 王堉茬. "REGIONAL CO2 EMISSIONS TREND AND FACTOR DECOMPOSITION ANALYSIS IN TAIWAN." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/24640107691398875661.

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碩士
國立臺北大學
經濟學系
101
Most of recent studies on CO2 reduction focus on national or multi-country level. However, both economic and environmental impacts of CO2 reduction policies are likely to vary across regions, national and multi-country averages belie the extremes at regional level. This study aims at analyzing regional CO2 emission trend in Taiwan. We first calculate the total and sectoral CO2 emissions in Taiwan during 1982~2011 based on the Reference Approach and Sectoral Approach suggested by IPCC (2006) and Bureau of Energy (2012). Secondly, we attempt to estimate the regional CO2 emissions. Becasue there is no regional energy consumption data in Taiwan, we decompose the sectoral CO2 emissions to the regional sector emissions using different indicators and then sum up the regional sector emissions to get regional CO2 emissions. Finally, we use factor decomposition method to analyze the factors respectively determining total CO2 emissions, sectoral CO2 emissions and regional CO2 emissions. Our result of regional emissions shows that the Northern region of Taiwan emits most of CO2 during our study period, which is about 40% of the total CO2 emissions every year. The Southern and Western regions of Taiwan are respectively the second and third emission resources. Their emissions are close to each other during the recent years. Each of them contributes to about 28% of total emissions in 2011. The last one is the Eastern region of Taiwan, which contributes to only 2% of total emissions in 2011. The result of factor decomposition analysis of total emission changes shows that the energy intensity effect is the mainly negative effect and the production and population effects are positive effects. The energy intensity effect is also the mainly negative effect and the production and scale effects are mainly positive effects in sectoral changes of CO2 emissions except transportation sector. In regional changes of CO2 emissions, the emission intensity is mainly negative effect and the income effect is mainly positive effect. The importance of regional CO2 emissions researches has been emphasized in these years. However, there is no statistics on regional energy or CO2 emissions published by the Taiwanese government. In order to calculate regional CO2 emissions more accurately, we suggest that regional energy consumption database should be developed. By doing so, the regional reduction and adaption policies can be designed more appropriately.

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Keen, Patterson Margaret. "Cycle decomposition, Steiner trees, and the facility layout problem." 2003. https://scholarworks.umass.edu/dissertations/AAI3110541.

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The facility layout problem is modelled as a cycle decomposition process in which the maximum-weight clique and travelling salesman problems are utilized to extract cycles from the graph adjacency matrix. The space between cycles is triangulated so the graph is maximally planar. The adjacency graph is then systematically developed into a block plan layout. With use of the maximum-weight clique algorithm, the procedure addresses layout problems that are not 100% dense. Many examples are utilized to demonstrate the flexibility of the algorithm and the resulting adjacency graph and block plan layout drawings. The Steiner Circulation Network solution derived from an adjacency graph solution and its dual graph, provides a minimum cost system of hallways and connecting links for the material handling system. Using the flows between activities and departments in a layout problem, the circulation network provides the necessary link between the steps of finding the adjacency graph solution and finding useful block plan layout. A case study demonstrates how the solution for the layout and its material handling system can be integrated. Computational results up to size n = 100 are presented along with a comparative study with a competitive algorithm.

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Wen, Cheng Di, and 鄭迪文. "Decomposition of Kn into directed cycle of length n-1." Thesis, 1999. http://ndltd.ncl.edu.tw/handle/00509938532139117326.

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碩士
淡江大學
數學學系
87
A graph can be described by two sets V and E. ie. G=(V,E) if V is a nonempty set, we called V a vertex set, E is a subset of two-element subset of V, we called E an edge set. If there is exactly one edge joining any pair of vertices of V and V contains n elements, we call G a complete graph with n vertices, denoted by Kn. If there are exactly m edges joining any pair of vertices of V, then we call G an m-fold complete graph with n vertices, Denote by mKn. If there are two edges with different directions connecting any pair of vertices in a complete graph with n vertices, then we call this graph a symmetric directed graph , denoted by Kn*. The decomposition problem is a problem which discusses how to decompose a graph G into edge-disjoint subgraphs of G. In 1981, Alspach conjectured that if and only if m1+m2+…+mt=n(n-1)/2 then there is a decomposition of Kn into edge-disjoint cycles, C1,C2,…,Ct，where the length of Ci is mi, for i=1,2,…,t. If m1= m2= …= mt=v then we call the set of these cycles with length v a v cycle system of order n. In this thesis. We discuss how to decompose Kn* into edge-disjoint directed cycles of length n-1 and 2Kn into edge-disjoint cycles of length n. We give constructions to both cases. At the same time, from the decomposition of Kn* we can get a decomposition of 2Kn.

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Jen, Shu Yi, and 任淑怡. "Taiwan Business Cycles and Oil Prices -Common Trend and Common Cycle Analysis." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/56264465183086128642.

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Shun-JingYou and 游順景. "CO2 Emission Decomposition and Input-Output Life Cycle Assessment for Textile Industry." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/x4s34b.

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AnantaPraditya and 葛仁多. "CO2 Emissions Trend and Input Output Life Cycle Assessment of Indonesia's Petroleum Refining Sector." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/zth63m.

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Chu, Chao-Ming, and 朱昭銘. "Using Technology Life Cycle to Analysis the Developing Trend of Thin-Film Photovoltaic Industry." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/34325975436021132503.

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碩士
國立中央大學
企業管理學系碩士在職專班
97
Over the passed decade, Taiwan’s high technology industries such as semiconductor and TFT-LCD had accumulated many experience and fundamentals. Due to recent years, green energy and energy-saving industry are boosted; many enterprises devote in Photovoltaic, solar and LED manufacturing. Especially thin film solar production has similar process with TFT-LCD, thus related skilled person and capital are attracted. This study leverages “US Patent and Trademark Office” database to query related key index to develop “S curve” by using “Technology Life Cycle” theory in order to estimate the mature time of each stage of the life cycle. Especially thin film solar technology life cycle is estimated with “logistic growth model” and software “Loglet Lab 2” is utilized to analysis the life cycle of thin film photovoltaic industry. The major conclusions of this study are as follows. For thin film solar technology, the life cycle is in technical maturity stage in 2009. The leading country patent quantities are US and Japan. Due to the technical life cycle is in maturity stage, it is suggested that for the companies ready to get in should choose ready technology and technical align with foreign technical leading company. Based on the rich experience of Taiwan LCD industry, the lower cost and higher reliable thin film photovoltaic industries can be developed to achieve the leading position in international market before solar industry life come to maturity stage at 2012.

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Kuo, Wen-hsiu, and 郭紋秀. "Combination of Life Cycle Assessment with Decomposition Analysis：Case Study of Fossil Power Plant." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/06192697386808833723.

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碩士
國立成功大學
環境工程學系碩博士班
97
Life cycle assessment was applied in this study to explore the environmental impacts caused by fossil-power plants in Taiwan. We used three models including Eco-Indicator 95, EPS 2000 and CML 2 from the SimaPro 7.1 program to compare the environmental impacts generated from various fossil fuels in power generation. In addition, the application of decomposition method was used to identify the major factors affecting CO2 emissions from the sector of power generation and results were comparied with other countries. We hope that results of this study can be of value for relevant study in life cycle assessment and how to reduce CO2 emissions for domestic power sector. The results showed that different types of fuels have similar influence on the environment categories. Major impact categories in Eco-Indicator 95 model include heavy metals, greenhouse and energy resources. The abiotic stock resource and human health were the mainly impact categories in EPS 2000 model categories. In the CML 2 model, the major impact category was marine aquatic ecotoxicity. Also, we analyzed the electricity consumption, CO2 emissions and economic growth changes from 1971 to 2006 in Taiwan, Australia, Canada, France, Germany, Ireland, Italy, Japan, Korea, Netherlands, New Zealand, China, Britain, the United States and the Czech Republic. The results indicated that the power sector is an important source of CO2 emissions for all countries. New Zealand has the fastest growth rate in electricity CO2 emission coefficient and total CO2 emissions intensity; China has the fastest growth rate in per capita CO2 emissions of electricity; Korea has the fastest growth rate in per capita electricity consumption and electricity intensity; Australia's per capita CO2 emissions of electricity was the largest comparied to other countries. Results from decomposition analysis indicated that GDP per capita was the major incremental factor to cause the increase of CO2 emissions for most countries. The electricity CO2 emission coefficient and electricity intensity were the mainly factors in reducing CO2 emission. Furthermore, the largest incremental of CO2 emissions was found in China, while Italy had the best performance with a total reduction up to 1.55 million tons during 1990 to 2005.

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Lu, I.-Jing, and 盧怡靜. "Decomposition and trend analyses of energy consumption and CO2 emission from the road traffic system in Taiwan." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/76835748710908388779.

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博士
國立成功大學
環境工程學系碩博士班
96
In this study, the decomposition analysis was adopted to explore the relative impacts of different factors on the aggregate energy consumption from the road transportation system and the private vehicles in Taiwan from 1990 to 2005. Also, the results from this method were then compared with the grey relation analysis (GRA). System dynamics model was constructed as a case study for passenger cars to simulate how vehicular operation, vehicular energy consumption and energy-related CO2 variations will be affected by the demographics, fuel price and economical growth. In order to project the future trends for the fleet size, traffic energy consumption and CO2 emissions from the road transportation system, the grey forecasting model, GM(1,1), was developed. Finally, the factors for the traffic CO2 emission increase in Germany, Japan, South Korea and Taiwan were examined to be helpful references for transportation-related CO2 emission reduction and enhancing vehicular energy efficiency in Taiwan. The major findings of this study are summarized as follows: 1.According to the results of decomposition methodology, the rapid growths of economy and vehicle kilometers per unit vehicle were two key factors for the rise of vehicular fuel demand, whereas the energy intensity had a considerable positive effect on energy conservation. As for the road transportation system, the index of economically active population intensity was another important component for energy decrease. The comparisons between passenger cars and motorcycles suggested that the increasing of vehicular structure share had a positive effect on the increase of fuel demand. 2.Results from the grey relation analysis revealed that the increase in vehicular fuel consumption can be attributed to the fleet size and growth of economy. The factor of GEK exhibited a positive grey relation as the length of vehicle kilometers grew higher than its energy requirement. In comparison to the other factors, the influence of the fuel price and economically active population were obscure since the growth patterns of the compared series and the reference series were inconsistent. 3.According to the simulation of the system dynamics model, the amount of passenger cars in 2025 will be 8.0 million vehicles, which is higher than that of in 1990 by 5.7 million vehicles. Accompanying the growth of fleet size, the vehicular fuel consumption and energy-related CO2 emission increase by 14.2 million kiloliters and 30.8 million metric tons during 1990-2025. The scenario analysis indicates that the restriction on the use of private vehicles has relatively notable effect on energy conservation and emission decrease and follows by the impact of higher fuel price, 3% of LPG vehicles and fuel tax. 4.Results by grey forecasting model showed that the energy demand and CO2 emitted by the road transportation system continued to rise at the annual growth rate of 3.25% and 3.23% over the next 18 years, respectively. Besides, the simulation of different economic development scenario were analyzed because of the economic driving force is an important factor for the increase of transportation demand and vehicular fuel consumption. It revealed that the upper and lower bound values of the number of motor vehicles in 2025 varies from 30.2 to 36.3 million vehicles, with the traffic energy requirement lies between 25.8 million kiloliters to 31.0 million kiloliters. The corresponding emission of CO2 will be 61.1 and 73.4 million metric tons in the low and high scenario profile, respectively. 5.Decomposition analysis in each countries suggested that the rapid growths of economy and vehicle ownership were two major factors for the rapid increase of traffic CO2 emission, whereas the index of population intensity contributed significantly to emission decrease. Also, the vehicular fuel consumption per ten thousand vehicle factor contributed a considerable emission decrease in all countries, except Taiwan.

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