91 research outputs found
Uncertainty Quantification for Naval Ships and the Optimal Adaptation of Bridges to Climate Change
Repairing and adapting existing structures and infrastructure is essential for maintaining the functionality of a transportation network and the flow of people, goods, and ideas across a region. However, structures are vulnerable to extreme events, such as hurricanes and floods, and continuous deterioration, due to exposure to corrosive environments and cyclic loading. The occurrence of extreme events may be nonstationary over the service life of the structures, leading to uncertain future loading conditions on the structure. Continuous deterioration, due to corrosion or fatigue, changes the capacity of the structure to resist loads over time. Repair and adaptation measures may be applied to a structure in order to improve the capacity to resist loads. However, limited economic resources prohibit the immediate repair and adaptation of all structures, thus requiring a systematic methodology be established prioritizing actions. It is because of this need that the field of life-cycle management has emerged. The focus of the research in this dissertation is on enhancing this field and the ability of engineers to (1) quantify uncertainty in the life-cycle management problem, (2) assess the performance of structures and develop effective management strategies, and (3) integrate the uncertainties of climate changes and future loading conditions into the management of structures.Uncertainty quantification typically involves describing the variability in the loads acting on a structure, the capacity of the structure, and the deterioration over time of the structure. In the design phase, uncertainty quantification is based on observing loads in the area (traffic, wind, hydraulic loads, etc) and testing materials and connections to characterize their properties. In the operational phase, Structural Health Monitoring (SHM) data can be integrated into the uncertainty quantification process. This research specifically enhances the ability to integrate SHM data into the fatigue life prediction of ship structures and improve uncertainty quantification for naval ships.Life-cycle management integrates the quantifiable uncertainties into the performance assessment of a structure. For civil structures, hydraulic hazards like hurricanes, floods, and tsunamis may cause extensive damage; and failure may have major economic, societal, and environmental consequences. This research focuses on enhancing the performance assessment methodologies for evaluating the risk associated with the failure of riverine and coastal bridges once the uncertainties are known. The considerations for the multiple failure modes, as well as the multiple hazards, included in this research are shown to be essential when determining the risk level of bridges. Furthermore, this work includes proposed methodologies for determining optimal management strategies that are driven by both performance and cost in order to aid decision makers.The final thrust area of this research emanates from the uncertainties associated with anticipated climate changes. Natural and anthropogenic changes result in changes to sea level, the intensity of storms, and the intensity of precipitation which leave riverine and coastal bridges increasingly vulnerable. The uncertainties that govern the future variability in climate are currently reported as unquantifiable. This type of uncertainty is referred to as a deep uncertainty and stems from the multiple feasible projections for gas concentrations and the multiple available climate models with which to evaluate them. This research introduces a systematic decision support framework for determining adaptation strategies in the presence of both the deep uncertainties of climate change and the quantifiable uncertainties of structural performanc
Inducible Nitric Oxide Synthase Induction Underlies Lipid-Induced Hepatic Insulin Resistance in Mice: Potential Role of Tyrosine Nitration of Insulin Signaling Proteins
Implication de la diaspora Togolaise dans la planification des projets de développement local: étude de cas du village de Bohou Tchamdè
L’implication de la diaspora dans la planification des actions de développement local est importante. Mais celle du village de Bohou-Tchamdè au Togo n’est pas impliquée à hauteur dans les initiatives de développement de ladite localité. Cette étude vise à déterminer d’une part le niveau d’implication et à analyser d’autre part les déterminants de l’implication de la diaspora Togolaise dans la planification des projets de développement local. Pour la rendre effective, notre méthodologie de collecte de l’information a été axée sur une enquête en ligne auprès des Ressortissants et Diaspora (Togolaise et d’origine du village de Bohou-Tchamdè) pour connaitre le degré d’implication et les facteurs qui déterminent leur implication. L’étude nous a permis d’aboutir à des résultats qui confirment que le niveau d’implication de la diaspora Togolaise (migrant interne et externe) est faible. En effet les facteurs qui influencent négativement la non implication de la diaspora Togolaise dans le processus de planification des projets de développement sont : le manque de stratégie (une feuille de route) ; l’absence des associations regroupant les diasporas pour une cause commune, le manque de liens de confiance entre la diaspora et les parents du pays ou milieu d’origine. En outre les variables comme le niveau d’instruction et le genre sont les déterminants qui influencent significativement l’implication de la diaspora
Risk-based cost-benefit analysis for the retrofit of bridges exposed to extreme hydrologic events considering multiple failure modes
Multi-criteria robust optimization framework for bridge adaptation under climate change
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