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Innervation cholinergique du cortex cérébral chez le rat adulte et en cours de développement : distribution quantifiée et analyse ultrastructuraleMechawar, Naguib January 2001 (has links)
Thèse numérisée par la Direction des bibliothèques de l'Université de Montréal.
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Framework for Estimating Performance and Associated Uncertainty of Modified Aircraft ConfigurationsDenham, Casey Leigh-Anne 22 June 2022 (has links)
Flight testing has been the historical standard for determining aircraft airworthiness - however, increases in the cost of flight testing and the accuracy of inexpensive CFD promote certification by analysis to reduce or replace flight testing. A framework is introduced to predict the performance in the special case of a modification to an existing, previously certified aircraft. This framework uses a combination of existing flight test or high fidelity data of the original aircraft as well as lower fidelity data of the original and modified configurations. Two methods are presented which estimate the model form uncertainty of the modified configuration, which is then used to conduct non-deterministic simulations. The framework is applied to an example aircraft system with simulated flight test data to demonstrate the ability to predict the performance and associated uncertainty of modified aircraft configurations. However, it is important that the models and methods used are applicable and accurate throughout the intended use domain. The factors and limitations of the framework are explored to determine the range of applicability of the framework. The effects of these factors on the performance and uncertainty results are demonstrated using the example aircraft system. The framework is then applied to NASA's X-57 Maxwell and each of its modifications. The estimated performance and associated uncertainties are then compared to the airworthiness criteria to evaluate the potential of the framework as a component to the certification by analysis process. / Doctor of Philosophy / Aircraft are required to undergo an airworthiness certification process to demonstrate the capability for safe and controlled flight. This has historically been satisfied by flight testing, but there is a desire to use computational analysis and simulations to reduce the cost and time required. For aircraft which are based on an aircraft which has already been certified, but contain minor changes, computational tools have the potential to provide a large benefit. This research proposes a framework to estimate the flight performance of these modified aircraft using inexpensive computational or ground based methods and without requiring expensive flight testing. The framework is then evaluated to ensure that it provides accurate results and is suitable for use as a supplement to the airworthiness certification process.
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Quantification, misc.Anderssen, Jan 01 September 2011 (has links)
This dissertation investigates various topics concerning the interpretation of determiner phrases and their connection to individual entities. The first chapter looks at a phenomenon called telescoping, in which a quantificational expression appears to bind a pronominal form across sentence boundaries, at odds with commonly assumed and well motivated constraints on binding. I investigate the limited circumstances under which telescoping is available and argue that the mechanism that makes it available should respect said locality constraints. In particular, I argue that the impression of co-variation arises not because of binding by the initial quantificational expression, but because an of independent, albeit unpronounced, quantificational operator in the second sentence. I will show cases where the domains of these two quantificational operators are independent, incompatible with approaches that assume a single operator. This result also entails that no reference to constructed individuals, e.g. prototypical or average individuals is needed. In the second chapter, I look at the German lexical item lauter and argue that DPs headed by lauter are purely predicational. After presenting an overview of the various kinds of interpretations that a DP can receive, and some discussion objecting to the idea of treating these as cases of lexical ambiguity, I show data that illustrate that lauter DPs cannot receive many of these interpretations. At the end of the chapter, I speculate about ways in which purely predicative DPs may appear and be interpreted in some, but not all, positions that arguments typically occupy, resulting in a restricted distribution and less freedom in the range of interpretations. In the last chapter, I look at an instance of a semantically complex determiner, the English item any. Instead of adding to the discussion based on an investigation of any, I propose that this hidden semantic complexity has a transparent reflex in German, where the lexical item überhaupt spells out a logically independent part of the proposed meaning of any, namely its domain widening meaning.
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Uncertainty Quantification in Neural Network-Based Classification ModelsAmiri, Mohammad Hadi 10 January 2023 (has links)
Probabilistic behavior in perceiving the environment and take critical decisions have
an inevitable role in human life. A decision is concerned with a choice among the
available alternatives and is always subject to unknown elements concerning the
future. The lack of complete data, insufficient scientific, behavioral, and industry
development and of course defects in measurement methods, affect the reliability of an
action’s outcome. Thus, having a proper estimation of this reliability or uncertainty
could be very advantageous particularly when an individual or generally a subject
is faced with a high risk. With the fact that there are always uncertainty elements
whose values are unknown and these enter into a processes through multiple sources,
it has been a primary challenge to design an efficient representation of confidence
objectively. With the aim of addressing this problem, a variety of researches have
been conducted to introduce frameworks in metrology of uncertainty quantification
that are comprehensive enough and have transferability into different areas. Moreover,
it’s also a challenging task to define a proper index that reflects more aspects of the
problem and measurement process.
With significant advances in Artificial Intelligence in the past decade, one of the
key elements, in order to ease human life by giving more control to machines, is to
heed the uncertainty estimation for a prediction. With a focus on measurement aspects, this thesis attends to demonstrate how a
different measurement index affects the quality of evaluated predictive uncertainty
of neural networks. Finally, we propose a novel index that shows uncertainty values
with the same or higher quality than existing methods which emphasizes the benefits
of having a proper measurement index in managing the risk of the outcome from a
classification model.
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ROBUST EXPERIMENTAL DESIGN FOR ESTIMATING MYOCARDIAL BETA ADRENERGIC RECEPTOR CONCENTRATION USING POSITRON EMISSION TOMOGRAPHYSalinas, Cristian Andres 03 April 2006 (has links)
No description available.
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CFD Analyses of Air-Ingress Accident for VHTRsHam, Tae Kyu 30 December 2014 (has links)
No description available.
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A Small-Perturbation Automatic-Differentiation (SPAD) Method for Evaluating Uncertainty in Computational ElectromagneticsGilbert, Michael Stephen 20 December 2012 (has links)
No description available.
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Inference of Constitutive Relations and Uncertainty Quantification in ElectrochemistryKrishnaswamy Sethurajan, Athinthra 04 1900 (has links)
This study has two parts. In the first part we develop a computational approach to the solution of an inverse modelling problem concerning the material properties of electrolytes used in Lithium-ion batteries. The dependence of the diffusion coefficient and the transference number on the concentration of Lithium ions is reconstructed based on the concentration data obtained from an in-situ NMR imaging experiment. This experiment is modelled by a system of 1D time-dependent Partial Differential Equations (PDE) describing the evolution of the concentration of Lithium ions with prescribed initial concentration and fluxes at the boundary. The material properties that appear in this model are reconstructed by solving a variational optimization problem in which the least-square error between the experimental and simulated concentration values is minimized. The uncertainty of the reconstruction is characterized by assuming that the material properties are random variables and their probability distribution estimated using a novel combination of Monte-Carlo approach and Bayesian statistics. In the second part of this study, we carefully analyze a number of secondary effects such as ion pairing and dendrite growth that may influence the estimation of the material properties and develop mathematical models to include these effects. We then use reconstructions of material properties based on inverse modelling along with their uncertainty estimates as a framework to validate or invalidate the models. The significance of certain secondary effects is assessed based on the influence they have on the reconstructed material properties. / Thesis / Doctor of Philosophy (PhD)
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Characterization of the Sinorhizobum Meliloti Chotaxis SystemCastaneda Saldana, Rafael 19 December 2019 (has links)
Increasing awareness to global climate change has drastically focused attention on finding solutions to reduce environmental impacts while still providing sufficient food for the increasing world population. Beneficial Nitrogen Fixing (BNF) microbes provide a possible solution by delivering biological nitrogen to plants resulting in reduced environmental impacts due to fertilizer runoff and eutrophication. One well studied model is that of Sinorhizobium meliloti and its legume host Medicago sativa (alfalfa), the fourth largest USA crop used for animal feed. Advancing research for this symbiosis model can provide solutions to enhance yield while minimizing environmental impacts.
Chapter 2 focuses on the deviation of the S. meliloti chemotaxis system from the enteric paradigm. Quantitative immunoblots determined the cellular amounts of chemotaxis proteins. Overall, chemotaxis protein levels were approximately 10-fold lower in S. meliloti compared to B. subtilis and E. coli. Focusing on cellular stoichiometric ratios, S. meliloti generally exhibits drastically higher values for CheB, CheR, and CheY to the histidine kinase CheA monomer compared to E. coli and B. subtilis.
Chapter 3 characterizes the role of McpX to quaternary ammonium compound (QAC) sensing. QACs are exuded by germinating alfalfa seeds. In vitro binding assays were performed to determine ligand binding characteristics. S. meliloti chemotaxis behavior to QACs was analyzed in in vivo capillary assays under real-time imaging.
These studies strengthen our knowledge of the chemotaxis system in the symbiosis model of S. meliloti and alfalfa. The data can further be used to create a mathematical model of the dynamics of bacteria-host interaction. The results can be used to optimize chemotaxis to host plants to improve crop yield and protect watersheds. / Master of Science / Increasing awareness of global climate change has drastically focused attention on finding solutions to reduce environmental impacts while still providing sufficient food for the increasing world population. Beneficial Nitrogen Fixing (BNF) microbes may offer a feasible solution in reducing environmental impacts by supplying biological nitrogen to plants, which reduces fertilizer use and ultimately runoff. One-well studied beneficial microbial model is that of Sinorhizobium meliloti and its legume host Medicago sativa (alfalfa), the fourth most cultivated USA crop used for animal feed. Advancing research for this symbiosis model can provide solutions to enhance crop yield while diminishing environmental impacts.
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Validation and Uncertainty Quantification of Doublet Lattice Flight Loads using Flight Test DataOlson, Nicholai Kenneth Keeney 19 July 2018 (has links)
This paper presents a framework for tuning, validating, and quantifying uncertainties for flight loads. The flight loads are computed using a Nastran doublet lattice model and are validated using measured data from a flight loads survey for a Cessna Model 525B business jet equipped with Tamarack® Aerospace Group’s active winglet modification, ATLAS® (Active Technology Load Alleviation System). ATLAS® allows for significant aerodynamic improvements to be realized by reducing loads to below the values of the original, unmodified airplane. Flight loads are measured using calibrated strain gages and are used to tune and validate a Nastran doublet-lattice flight loads model. Methods used to tune and validate the model include uncertainty quantification of the Nastran model form and lead to an uncertainty quantified model which can be used to estimate flight loads at any given flight condition within the operating envelope of the airplane. The methods presented herein improve the efficiency of the loads process and reduce conservatism in design loads through improved prediction techniques. Regression techniques and uncertainty quantification methods are presented to more accurately assess the complexities in comparing models to flight test results. / Master of Science / This paper presents a process for correlating analytical airplane loads models to flight test data and validating the results. The flight loads are computed using Nastran, a structural modeling tool coupled with an aerodynamic loads solver. The flight loads models are correlated to flight test data and are validated using measured data from a flight loads survey for a Cessna Model 525B business jet equipped with Tamarack ® Aerospace Group’s active winglet modification, ATLAS ® (Active Technology Load Alleviation System). ATLAS ® allows for significant aerodynamic improvements and efficiency gains to be realized by reducing loads to below the values of the original, unmodified airplane. Flight loads are measured using a series of strain gage sensors mounted on the wing. These sensors are calibrated to measure aerodynamic loads and are used to tune and validate the Nastran flight loads model. Methods used to tune and validate the model include quantification of error and uncertainties in the model. These efforts lead to a substantially increased understanding of the model limitations and uncertainties, which is especially valuable at the corners of the operating envelope of the airplane. The methods presented herein improve the efficiency of the loads process and reduce conservatism in design loads through improved prediction techniques. The results provide a greater amount of guidance for decision making throughout the design and certification of a load alleviation system and similar airplane aerodynamic improvements.
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