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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
391

<b>Genomic background of calf resilience and milk feeding traits based on automated feeder data in Holstein cattle</b>

Jason Robert Graham (19212595) 28 July 2024 (has links)
<p dir="ltr">In this dissertation, we investigated the genetic background of milk consumption, feeding behavior, disease resistance, and calf resilience in North American Holstein dairy calves using precision livestock farming (PLF) technologies and genetic modeling. Genomic and phenotypic information obtained from automatic milk feeding machines were obtained from 10,072 pre-weaned Holstein calves and used to derive and genetically evaluate novel traits such as daily milk consumption, calf resilience, and incidence of bovine respiratory disease (BRD). Heritability estimates for milk consumption and feeding behavior traits were found to be low but improved with specific statistical models, suggesting potential for genetic improvement if included in selection schemes. Random regression models captured greater amounts of genetic variability among calves for longitudinal milk feeding and behavior traits, with moderate negative (favorable) genetic correlations between milk consumption and BRD, indicating potential for genetic selection to enhance calf health outcomes and performance based on milk intake data. Various quantitative trait loci (QTL) for milk consumption, drinking duration traits, feeding behavior, and disease susceptibility were identified, linking key genes involved in metabolic processes, growth, and overall health. The same datasets were used to derive resilience indicators based on cumulative milk consumption. Genetic parameters for resilience traits, including amplitude, perturbation time, and recovery time, were estimated, highlighting substantial phenotypic and genetic variability. Significant genomic regions for six resilience traits were identified, with key genes such as <i>ABCB8</i>,<i> ABCF2</i>, and <i>AGAP3</i> linked to resilience traits, impacting mitochondrial function, cellular stress responses, and homeostasis. Pathway analyses revealed critical biological processes for stress response, including nucleotide binding and hormone activity. Genes such as <i>EPC1</i>, <i>ASB10</i>, and <i>ASIC3</i> were associated with recovery time, while <i>DPP6</i>, <i>GBX1</i>, and <i>GIMAP5</i> were linked to other resilience traits. These findings underscore the importance of genetic tools and breeding strategies in enhancing health, resilience, and productivity, offering potential new traits to genetically improve health and resilience in dairy cattle, and consequently, improve the sustainability of the dairy cattle industry.</p>
392

Etude des marchés d'assurance non-vie à l'aide d'équilibre de Nash et de modèle de risques avec dépendance

Dutang, Christophe 31 May 2012 (has links) (PDF)
L'actuariat non-vie étudie les différents aspects quantitatifs de l'activité d'assurance. Cette thèse vise à expliquer sous différentes perspectives les interactions entre les différents agents économiques, l'assuré, l'assureur et le marché, sur un marché d'assurance. Le chapitre 1 souligne à quel point la prise en compte de la prime marché est importante dans la décision de l'assuré de renouveler ou non son contrat d'assurance avec son assureur actuel. La nécessitéd'un modèle de marché est établie. Le chapitre 2 répond à cette problématique en utilisant la théorie des jeux non-coopératifs pour modéliser la compétition. Dans la littérature actuelle, les modèles de compétition seréduisent toujours à une optimisation simpliste du volume de prime basée sur une vision d'un assureur contre le marché. Partant d'un modèle de marché à une période, un jeu d'assureurs est formulé, où l'existence et l'unicité de l'équilibre de Nash sont vérifiées. Les propriétés des primes d'équilibre sont étudiées pour mieux comprendre les facteurs clés d'une position dominante d'un assureur par rapport aux autres. Ensuite, l'intégration du jeu sur une période dans un cadre dynamique se fait par la répétition du jeu sur plusieurs périodes. Une approche par Monte-Carlo est utilisée pour évaluer la probabilité pour un assureur d'être ruiné, de rester leader, de disparaître du jeu par manque d'assurés en portefeuille. Ce chapitre vise à mieux comprendre la présence de cycles en assurance non-vie. Le chapitre 3 présente en profondeur le calcul effectif d'équilibre de Nash pour n joueurs sous contraintes, appelé équilibre de Nash généralisé. Il propose un panorama des méthodes d'optimisation pour la résolution des n sous-problèmes d'optimisation. Cette résolution sefait à l'aide d'une équation semi-lisse basée sur la reformulation de Karush-Kuhn-Tucker duproblème d'équilibre de Nash généralisé. Ces équations nécessitent l'utilisation du Jacobiengénéralisé pour les fonctions localement lipschitziennes intervenant dans le problème d'optimisation.Une étude de convergence et une comparaison des méthodes d'optimisation sont réalisées.Enfin, le chapitre 4 aborde le calcul de la probabilité de ruine, un autre thème fondamentalde l'assurance non-vie. Dans ce chapitre, un modèle de risque avec dépendance entre lesmontants ou les temps d'attente de sinistre est étudié. De nouvelles formules asymptotiquesde la probabilité de ruine en temps infini sont obtenues dans un cadre large de modèle de risquesavec dépendance entre sinistres. De plus, on obtient des formules explicites de la probabilité deruine en temps discret. Dans ce modèle discret, l'analyse structure de dépendance permet dequantifier l'écart maximal sur les fonctions de répartition jointe des montants entre la versioncontinue et la version discrète.
393

Etude théorique d'indicateurs d'analyse technique

Ibrahim, Dalia 08 February 2013 (has links) (PDF)
Dans le cadre de ma thèse, je me suis intéressée à analyser mathématiquement un indicateur de rupture de volatilité très utilisé par les praticiens en salle de marché. L'indicateur Bandes de Bollinger appartient à la famille des méthodes dites d'analyse technique et donc repose exclusivement sur l'historique récente du cours considéré et un principe déduit des observations passées des marchés, indépendamment de tout modèle mathématique. Mon travail consiste à étudier les performances de cet indicateur dans un univers qui serait gouverné par des équations différentielles stochastiques (Black -Scholes) dont le coefficient de diffusion change sa valeur à un temps aléatoire inconnu et inobservable, pour un praticien désirant maximiser une fonction objectif (par exemple, une certaine utilité espérée de la valeur du portefeuille à une certaine maturité).
394

Couverture des produits dérivés par minimisation locale de critères de risque convexes

Millot, Nicolas 17 February 2012 (has links) (PDF)
On s'intéresse dans cette thèse à la couverture des produits dérivés dans des marchés incomplets. L'approche choisie peut se voir comme une extension des travaux de M. Schweizer sur la minimisation locale du risque quadratique. En effet, tout en restant dans le cadre de la modélisation des actifs par des semimartingales, notre méthode consiste à remplacer le critère de risque quadratique par un critère de risque plus général, sous la forme d'une fonctionnelle convexe du coût local. Nous obtenons d'abord des résultats d'existence, d'unicité et de caractérisation des stratégies optimales dans un marché sans friction, en temps discret et en temps continu. Puis nous explicitons ces stratégies dans le cadre de modèles de diffusion avec et sans sauts. Nous étendons également notre méthode au cas où la liquidité n'est plus infinie. Enfin nous montrons par le biais de simulations numériques les effets du choix de la fonctionnelle de risque sur la constitution du portefeuille optimal.
395

Assessment of Small Sensory Fibers in Carpal Tunnel Syndrome Using Quantitative Sensory Testing

Mackie, Mahsa Unknown Date
No description available.
396

Internationalization of Family Businesses in Saudi Arabia

Bouges, Farid Fouad 01 January 2011 (has links)
Family businesses represent a key economical asset in the global economy. Leaders of family businesses have implemented internationalization as a key strategy to enhance sustainability and increase profitability in a hypercompetitive global marketplace. Guided by the Uppsala model, the purpose of this case study was to explore how Saudi family business leaders have planned and implemented internationalization. Three leaders from different international Saudi family businesses participated in semistructured interviews. The participants described their experience in achieving successful internationalization for their family businesses. After analyzing the interview data and validating through member checking, 3 main themes emerged: (a) the characteristics of the family business to compete internationally, (b) the characteristics of a suitable international market for family businesses to internationalize, and (c) the characteristics of a successful internationalization opportunity for a Saudi family business. In order to internationalize, Saudi family business leaders identified having a proper strategy, financial capability, qualified resources, well-structured policies, and globally-standardized products or services. Family business leaders should target the international market that is stable, that is secure with regulations, and that is welcoming to foreign investments. Each internationalization opportunity should have close psychic distance, available relationships in the international market, targeted family business motives, demonstrated existing market demand with the ability to satisfy, and proper timing. The findings may promote social change in Saudi family businesses by identifying essential characteristics to maintain the companies' existence and offer a roadmap to compete internationally.
397

Comparison of various methods of mitigating over pressure induced release events involving ammonia refrigeration using quantitative risk analysis (QRA)

Hodges, Tyler January 1900 (has links)
Master of Science / Department of Mechanical Engineering / Donald L. Fenton / This project was done to determine the effectiveness of different methods of mitigating the effects of an ammonia release through a pressure relief device in an ammonia refrigeration system. Several methods were considered, and five were selected for further study. The methods chosen for further study were discharge into a tank containing standing water, discharge into the atmosphere, discharge into a flare, discharge into a wet scrubber, and an emergency pressure control system. Discharge into a tank containing standing water is the most common method in existence today but several people in the ammonia refrigeration industry have questioned its reliability. The methods were compared based on a quantitative risk analysis, combining failure rates of each system with ammonia dispersion modeling and the monetized health effects of a system’s failure to contain an ammonia release. It was determined that the release height had a greater influence on the downwind cost impact than any other variable, including weather conditions and release from multiple sources. The discharge into a tank containing standing water was determined to have the lowest failure rate, while the flare system was found to be the most effective in terms of relative overall release consequent cost. The emergency pressure control system is now required by the codes, and any of the other mitigation systems would be very effective when used in conjunction with the emergency pressure control system.
398

Blågult – två lag på lika villkor? : En kvantitativ innehållsanalys av den journalistiska bevakningen i svensk kvällspress av de svenska herroch damlandslagen i fotboll / Representing Sweden – But on the same conditions?

Gunnarsson, Linus, Ternblad, Noah January 2012 (has links)
This essay examines if there is any difference how the two biggest tabloids in Sweden, Aftonbladet and Expressen is portraying the Swedish national football team for both woman and men. The purpose is to compare and see if there is any difference regarding what gender you have. We have also examined what gender the authors for the articles have. We have used a quantitative content analysis to get our results. In conclusion, there is a big difference in medial space regarding what gender you have. But there is no significant difference how the reporters are using their language depending what national team they’re writing about. There is also a big majority of male reporters that writes about the national teams.
399

Multiple-trait multiple-interval mapping of quantitative-trait loci

Joehanes, Roby January 1900 (has links)
Master of Science / Department of Statistics / Gary L. Gadbury / QTL (quantitative-trait locus) analysis aims to locate and estimate the effects of genes that are responsible for quantitative traits, such as grain protein content and yield, by means of statistical methods that evaluate the association of genetic variation with trait (phenotypic) variation. Quantitative traits are typically polygenic, i.e., controlled by multiple genes, with varying degrees of in uence on the phenotype. Several methods have been developed to increase the accuracy of QTL location and effect estimates. One of them, multiple interval mapping (MIM) (Kao et al. 1999), has been shown to be more accurate than conventional methods such as composite interval mapping (CIM) (Zeng 1994). Other QTL analysis methods have been developed to perform additional analyses that might be useful for breeders, such as of pleiotropy and QTL-by-environment (QxE) interaction. It has been shown (Jiang and Zeng 1995) that these analyses can be carried out with a multivariate extension of CIM (MT-CIM) that exploits the correlation structure in a set of traits. In doing so, this method also improves the accuracy of QTL location detection. This thesis describes the multivariate extension of MIM (MT-MIM) using ideas from MT-CIM. The development of additional multivariate tests, such as of pleiotropy and QxE interaction, and several methods pertinent to the development of MT-MIM are also described. A small simulation study shows that MT-MIM is more accurate than MT-CIM and univariate MIM. Results for real data show that MT-MIM is able to provide a more accurate and precise estimate of QTL location.
400

The use of mixed methods as reflected in two eminent South African educational research journals

Schulze, S., Kamper, G. January 2012 (has links)
Published Article / The epistemological and ontological orientations relevant for this research are positivism, interpretivism and pragmatism. These paradigms of inquiry are associated with quantitatively oriented research traditions, qualitatively oriented research traditions and mixed methods research respectively. Researchers who use mixed methods build on the strengths of quantitative and qualitative methods and minimize their weaknesses. Since educational research is primarily evidence-based, the aim of the study was to explore the extent to which mixed methods research was reflected in two eminent South African educational research journals during the 11 year period, 2000 to 2010. To this end 1392 articles were analysed. Of the research articles published in the two journals, 17.8% and 15.1% respectively reported on the use of mixed methods. Quantitative methods dominated between 2000 and 2002, followed by a paradigm war in 2003 to 2007, and mainly qualitative methods from 2008 onwards. Mixed methods research was mostly used in the educational domains of didactics (inclusive of curriculum studies), management and social studies. The most dominant themes investigated in these fields were related to curricula and the NQF/OBE, transformation, staff diversity, e-learning and other teaching methods. The need to develop mixed methods research in all branches of social research in South Africa is indicated.

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