Dissertations / Theses on the topic 'Diffusion prediction'
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D’Agostino, Carmine, Geoff D. Moggridge, Lynn F. Gladden, and Mick D. Mantl. "Prediction of mutual diffusion coefficients in non-ideal binary mixtures from PFG-NMR diffusion measurements." Diffusion fundamentals 20 (2013) 109, S. 1-2, 2013. https://ul.qucosa.de/id/qucosa%3A13698.
Full textD’Agostino, Carmine, Geoff D. Moggridge, Lynn F. Gladden, and Mick D. Mantl. "Prediction of mutual diffusion coefficients in non-ideal binary mixtures from PFG-NMR diffusion measurements." Universitätsbibliothek Leipzig, 2015. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-184023.
Full textNowicki, Timothy. "Statistical model prediction of fatigue life for diffusion bonded Inconel 600 /." Online version of thesis, 2008. http://hdl.handle.net/1850/7984.
Full textPirot, Fabrice. "Analyse, mesure et prediction de la diffusion dans le stratum corneum humain." Besançon, 1996. http://www.theses.fr/1996BESA3710.
Full textZhu, Qingyong, Geoffrey D. Moggridge, and Carmine D’Agostino. "A local composition model for the prediction of mutual diffusion coefficients in binary liquid mixtures from tracer diffusion coefficients." Universitätsbibliothek Leipzig, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-198798.
Full textZhu, Qingyong, Geoffrey D. Moggridge, and Carmine D’Agostino. "A local composition model for the prediction of mutual diffusion coefficients in binary liquid mixtures from tracer diffusion coefficients: A local composition model for the prediction of mutual diffusioncoefficients in binary liquid mixtures from tracer diffusion coefficients." Diffusion fundamentals 24 (2015) 58, S. 1, 2015. https://ul.qucosa.de/id/qucosa%3A14577.
Full textLong, Xiaoyan. "Prediction of shear strength and vertical movement due to moisture diffusion through expansive soils." Texas A&M University, 2006. http://hdl.handle.net/1969.1/4313.
Full textReynier, Alain. "Modelisation et prediction de la migration des additifs des emballages alimentaires." Reims, 2000. http://www.theses.fr/2000REIMS004.
Full textChang, Hojoon. "Prediction of Soot Formation in Laminar Opposed Diffusion Flame with Detailed and Reduced Reaction Mechanisms." Thesis, Georgia Institute of Technology, 2004. http://hdl.handle.net/1853/4922.
Full textAtwood, Robert Carl. "A combined cellular automata and diffusion model for the prediction of porosity formation during solidification." Thesis, Imperial College London, 2001. http://hdl.handle.net/10044/1/11433.
Full textEmadi, Mohammad Ali. "Prediction of molecular diffusion coefficients of gases in hydrocarbon liquids at high pressure and temperature." Thesis, University of Surrey, 2004. http://epubs.surrey.ac.uk/843592/.
Full textJackson, Eric Alan. "Towards a Prediction of Landscape Evolution from Chemical Weathering and Soil Production." Wright State University / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=wright1516116071724445.
Full textKuwahara, Ryo. "A Predictor of Tumor Recurrence in Patients With Endometrial Carcinoma After Complete Resection of the Tumor: The Role of Pretreatment Apparent Diffusion Coefficient." Kyoto University, 2020. http://hdl.handle.net/2433/253483.
Full textWang, Yanxin. "Hypoxic-ischemic injury in the neonatal rat model prediction of irreversible infarction size by Diffusion Weighted MR Imaging /." Click to view the E-thesis via HKUTO, 2005. http://sunzi.lib.hku.hk/hkuto/record/B35757577.
Full textTruc, Olivier. "Prediction of chloride penetration into saturates concrete - multi-species approach." Toulouse, INSA, 2000. http://www.theses.fr/2000ISAT0019.
Full textJungkuist, David Alan. "Simulation of Enviro-mechanical Durability for Life Prediction of E-Glass/Vinyl Ester Composites using a Bridge Service Environment." Thesis, Virginia Tech, 2000. http://hdl.handle.net/10919/32791.
Full textMaster of Science
Goswami, Tarun. "Sublingual drug delivery: In vitro characterization of barrier properties and prediction of permeability." Scholarly Commons, 2008. https://scholarlycommons.pacific.edu/uop_etds/2370.
Full textLiu, Xiaomo. "Online Knowledge Community Mining and Modeling for Effective Knowledge Management." Diss., Virginia Tech, 2013. http://hdl.handle.net/10919/50646.
Full textPh. D.
Bohlin, Johannes. "Lifetime prediction of a polymeric propellant binder using the Arrhenius approach." Thesis, Uppsala universitet, Tillämpad materialvetenskap, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-446609.
Full textHamadeh, Nizar. "Le développement de la loi de diffusion des incendies en modélisant le niveau de danger et son évolution dans le temps. : comparaison avec des données expérimentales dans les forêts libanaises." Thesis, Angers, 2017. http://www.theses.fr/2017ANGE0060/document.
Full textWildland fires are one of the most complex phenomena facing our societies. Lebanon, a part of Middle East, is losing its green forests dramatically mainly due to severe fires. This dissertation studies the phenomenon of forest fires. It proposes new models and methodologies to tackle the crisis of forest fires particularly in Lebanon and Mediterranean. It is divided into two main parts: New Approaches in Forest Fire Prediction and Forest Fire modeling. The first part is sub-divided into 3 chapters. First chapter presents an analytical study of the most widely used metrological models that can predict forest fires. In the second chapter we apply five data mining techniques methods: Neural Networks, Decision Tree, Fuzzy Logic, Linear Discriminate Analysis and Support Vector Machine. We aim to find the most accurate technique in forecasting forest fires. In the third chapter, we use different correlative data analysis techniques (Regression, Pearson, Spearman and Kendall-tau) to evaluate the correlation between fire occurrence and meteorological data (Temperature, Dew point, Soil temperature, Humidity, Precipitation and Wind speed). This allows to find the most influential parameters that affect the occurrence of fire, which lead us to develop a new Lebanese fire danger Index (LI). The proposed index is then validated using meteorological data for the years 2015-2016. The second part is sub-divided into 3 chapters. The first chapter reviews the fire behavior characteristics and its morphology; and focuses on the validity of mathematical and computer fire behavior models. The second chapter manifests the importance of cellular automata, explains the main types of cellular automata and reviews some applications in various domains. In the third chapter, we use cellular automata to develop a new behavior model for predicting the spread of fire, on elliptical basis, in both homogeneous and heterogeneous landscapes .The proposed methodology incorporates the parameters of wind speed, fuel and topography. The developed model is then used to simulate the wildfire that swept through the forest of Aandqet village, North Lebanon. Obtained simulation results are compared with reported results of the real incident and with simulations done on Karafyllidis model and Gazmeh-Modified Karafyllidis model. These comparisons have proven the outperformance of the proposed model. In this dissertation, the crisis of forest fires has been studied and new models have been developed in both phases: pre-fire and post-fire. These models can be used as efficient preventive tools in forest fire management
Donner, Quentin. "Correction de l'atténuation et du rayonnement diffusé en tomographie d'émission à simples photons." Université Joseph Fourier (Grenoble), 1994. http://www.theses.fr/1994GRE10155.
Full textThe aim of single photon emission tomography is to compute a functional picture of an organ. This is done by administering to the patient a radiopharmaceutical which is fixing in the organ. Then, one computes the distribution of the radiopharmaceutical from the measurement of the emitted gamma-rays. However, an important part of these gamma-rays are interacting with the matter inside the body. The aim of this work is to take these interactions into account so as to reconstruct more accurately. .
Elazar, Yekutiel. "A mapping of the viscous flow behavior in a controlled diffusion compressor cascade using laser doppler velocimetry and preliminary evaluation of codes for the prediction of stall." Thesis, Monterey, California. Naval Postgraduate School, 1988. http://hdl.handle.net/10945/23296.
Full textLundberg, Emil. "Adding temporal plasticity to a self-organizing incremental neural network using temporal activity diffusion." Thesis, KTH, Skolan för datavetenskap och kommunikation (CSC), 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-180346.
Full textVektorkvantisering (VQ; eng: Vector Quantization) är ett klassiskt problem och en enkel metod för mönsterigenkänning. Bland tillämpningar finns förstörande datakompression, klustring och igenkänning av tal och talare. Även om VQ i stort har ersatts av tidsmedvetna tekniker såsom dolda Markovmodeller (HMM, eng: Hidden Markov Models) och dynamisk tidskrökning (DTW, eng: Dynamic Time Warping) i vissa tillämpningar, som tal- och talarigenkänning, har VQ ännu viss relevans tack vare sin mycket lägre beräkningsmässiga kostnad — särskilt för exempelvis inbyggda system. En ny studie demonstrerar också ett VQ-system med flera sektioner som åstadkommer prestanda i klass med DTW i en tillämpning på igenkänning av handskrivna signaturer, men till en mycket lägre beräkningsmässig kostnad. Att dra nytta av temporala mönster i en VQ-algoritm skulle kunna hjälpa till att förbättra sådana resultat ytterligare. SOTPAR2 är en sådan utökning av Neural Gas, en artificiell neural nätverk-algorithm för VQ. SOTPAR2 använder en konceptuellt enkel idé, baserad på att lägga till sidleds anslutningar mellan nätverksnoder och skapa “temporal aktivitet” som diffunderar genom anslutna noder. Aktiviteten gör sedan så att närmaste-granne-klassificeraren föredrar noder med hög aktivitet, och författarna till SOTPAR2 rapporterar förbättrade resultat jämfört med Neural Gas i en tillämpning på förutsägning av en tidsserie. I denna rapport undersöks hur samma utökning påverkar kvantiserings- och förutsägningsprestanda hos algoritmen självorganiserande inkrementellt neuralt nätverk (SOINN, eng: self-organizing incremental neural network). SOINN är en VQ-algorithm som automatiskt väljer en lämplig kodboksstorlek och också kan användas för klustring med godtyckliga klusterformer. Experimentella resultat visar att denna utökning inte förbättrar prestandan hos SOINN, istället försämrades prestandan i alla experiment som genomfördes. Detta resultat diskuteras, liksom inverkan av parametervärden på prestandan, och möjligt framtida arbete för att förbättra resultaten föreslås.
Moulton, Eric. "Methodological Considerations and Clinical Relevance of Diffusion Tensor Imaging in Acute Stroke Prognosis." Thesis, Sorbonne université, 2019. http://www.theses.fr/2019SORUS249.
Full textPredicting motor, language, and global outcome after ischemic stroke is a major research concern. While initial impairment, age, and lesion volume have proven indicators of future outcome, the preservation of major white matter structures also play a role in these outcome domains. Diffusion tensor imaging (DTI) is sensitive to acute ischemic damage and can evaluate the integrity of important white matter bundles. Using a large cohort of patients who underwent a DTI protocol at 24 hours post-stroke and a clinical evaluation 3 months afterwards, the current thesis sought to (1) investigate spatial normalization strategies to optimally analyze imaging data, (2) establish which DTI parameter best predicts global outcome, and (3) determine if DTI can provide independent biomarkers of motor and language outcome. The major findings of the current thesis were: (1) fiber orientation distribution (FOD)-based spatial normalization performed similarly to scalar normalization for acute stroke data but yielded stronger anatomo-clinical correlations in subacute-chronic stroke patients, (2) axial diffusivity (AD) in the corona radiata highly contributes to the prediction of autonomy in patients, and (3) the AD of the corticospinal tract and arcuate fasciculus are independent markers of motor and aphasia outcome, respectively. These results support the use of AD for quantifying early brain damage in important white matter structures, such as the corona radiata, corticospinal tract, and arcuate fasciculus. These markers could be used for patient information, as surrogates of neuroprotective therapies at the hyperacute stage, or as stratification means for rehabilitative therapies
Ho, Thi Kim Thoa. "Modélisation et analyse des réseaux complexes associées à des informations textuelles : les apports de la prétopologie, du topic modeling et de l’apprentissage automatique à l’étude de la dynamique des réseaux sociaux, la prédiction de liens et la diffusion des sujets." Thesis, Université Paris sciences et lettres, 2020. http://www.theses.fr/2020UPSLP047.
Full textThis thesis deals with the concept of complex network associated with textual information. We are interested in the analysis of these networks with a perspective of application to social networks. Our first contribution consisted in building an analysis model for a dynamic social network using the agent based modeling (ABM) approach, author-topic modeling (ATM), and using the mathematical framework of pretopology to represent the proximity of the subjects. Our modeling is called Textual-ABM. Our proposal has been to use author-topic modeling to estimate user interest based on text content and to use pretopology to model several relationships and to represent a set of neighborhoods that is more elaborate than a simple relationship. Our second contribution concerns the diffusion of information on a "heterogeneous" social network. We propose to extend the independent cascade epidemic diffusion model (IC) and the pretopological cascade diffusion model that we call Textual-Homo-IC and Textual-PCM respectively. For Textual-Homo-IC, the probability of infection is based on homophilia (resemblance of agents) which is obtained from the textual content using the topic modeling. For Textual-PCM, a pseudo-closure function with different strong levels is proposed to realize a more complex set of neighborhoods. In addition, we propose to use supervised learning to predict the diffusion of a topic with a combination of intrinsic or external factors. Our third contribution concerns the prediction of relationships between co-authors with the addition of a new topological feature related to geographical factors and content features using topic modelling. All this work was achieved by the design of specific algorithms and validated by experiments
Francois, heude Alexandre. "Kinetic modeling of the polypropylene photothermal oxidation." Phd thesis, Ecole nationale supérieure d'arts et métiers - ENSAM, 2014. http://pastel.archives-ouvertes.fr/pastel-01069008.
Full textDeshpande, Rutooj D. "UNDERSTANDING AND IMPROVING LITHIUM ION BATTERIES THROUGH MATHEMATICAL MODELING AND EXPERIMENTS." UKnowledge, 2011. http://uknowledge.uky.edu/cme_etds/4.
Full textShain, Cory Adam. "Language, time, and the mind: Understanding human language processing using continuous-time deconvolutional regression." The Ohio State University, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=osu1619002281033782.
Full textCheng, Hua. "Hydrodynamic control of retention in heterogeneous aquifers and fractured rock." Doctoral thesis, Stockholm : KTH Architecture and the Built Environment, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-496.
Full textTrochmann, Jose Luiz Lino. "Simulação atomistica como ferramenta para investigação dos mecanismos de difusão : coeficientes de autodifusão de gases simples em matriz polimerica." [s.n.], 2006. http://repositorio.unicamp.br/jspui/handle/REPOSIP/266175.
Full textTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica
Made available in DSpace on 2018-08-07T03:49:14Z (GMT). No. of bitstreams: 1 Trochmann_JoseLuizLino_D.pdf: 1070584 bytes, checksum: 3407aee7ad6d88d9de0a1326aaf3d29d (MD5) Previous issue date: 2006
Resumo: Neste trabalho de tese foi realizado um estudo do potencial de predição de propriedades de transporte em matrizes poliméricas de poli - imidas, utilizando a simulação dinâmica molecular de gases simples como Oxigênio, Nitrogênio e Dióxido de Carbono. A propriedade de transporte de interesse prático, a permeabilidade de uma membrana polimérica a um dado penetrante, envolve a determinação de propriedades de ordem cinética e termodinâmica, respectivamente a determinação do coeficiente de difusão e da solubilidade deste penetrante na matriz polimérica. Atenção especial foi conferida à propriedade cinética, pela predição do coeficiente de autodifusão dos penetrantes. Num procedimento experimental clássico é de vital importância para significância das conclusões derivadas dos experimentos, o uso de amostras de membranas poliméricas adequadamente preparadas quanto à composição química, estrutura física e morfologia. Analogamente, quando se utiliza a simulação molecular para a predição de propriedades, tais como o coeficiente de autodifusão, também é de fundamental relevância para os resultados obtidos, a qualidade dos modelos moleculares das matrizes poliméricas, que serão usados como base. Assim para a preparação de modelos moleculares com o adequado empacotamento, um procedimento para a obtenção de modelos bem equilibrados foi desenvolvido neste trabalho. Os modelos moleculares desenvolvidos foram usados para a obtenção dos valores de massa específica em função da temperatura, e comparados aos valores experimentais disponíveis e quando necessário a, valores preditos por meio da expressão de massa específica em função da temperatura, acima e abaixo da temperatura de transição. A capacidade do modelo molecular desenvolvido em predizer a massa especifica e temperatura de transição vítrea foi usada como critério para a validação da adequação do empacotamento proposto para o referido modelo molecular da matriz polimérica. Os modelos validados de empacotamento, células amorfas, foram utilizados para o cálculo do coeficiente de autodifusão dos gases acima mencionados, através do da simulação dinâmica molecular. A comparação dos coeficientes de autodifusão obtidos das poli-imidas aromáticas e éster imidas, BAAF, 6FDA-ODA, PMDA-ODA e BA-20DA, para os gases O2, N2 e CO2, com os dados experimentais, permitiu concluir a adequação das células amorfas e do esquema de simulação dinâmica molecular para a predição do coeficiente de autodifusão.. A versão preditiva de Vrentas e Duda, baseada na teoria do volume livre, foi utilizada para a predição dos coeficientes de autodifusão da água e do etanol para as poli-imidas acima. , Estes valores, quando comparados com os valores obtidos através da simulação dinâmica molecular mostram a validade de ambas as teorias para a predição da cinética de difusão de penetrantes em matrizes poliméricas complexas
Abstract: In this thesis a study of the predictive potential of the molecular dynamic simulation was performed for transport properties of light gases in polyimide matrix. From de practical point of view permeability is the property of most interest, and involves kinetics as well as thermodynamics properties, diffusion coefficient and solubility of the penetrants molecule in the bulk polymeric matrix, this work will be focus in the former. As important as is in as experimental work, a well prepared polymeric membrane is essential for the significance of the draw conclusions. Therefore a special attention was take in the preparation of the bulk molecular polymeric model, the so called amorphous cell, in order to obtain well-equilibrated molecular packing models for the polyimide matrixes. The amorphous cells were prepared throughout thermodynamic transforms, using one or more of the statistical ensembles and cell specific volume obtained as a function of temperature, this data was compared against the experimental data available, and when necessary to data obtained via predictive methods. The molecular packing model ability to predict the glass transition temperature was used as criteria to validate de amorphous cell, to be used in the molecular dynamic' simulations allow the matrix to be locally flexible and coupled to the classic molecular dynamics simulation. The resulting self diffusion coefficients for the polyimide, BAAF, 6FDA-ODA, PMDAODA and BA-20DA for the gases O2, N2 e CO2 were compared to the experimental data. The lack of quality experimental diffusion data available for polyimide membranes for larger penetrants as water and ethanol, showed up as a good opportunity to assess the predictive capability of the molecular dynamic simulation for self diffusion coefficients, considering the relevant technological relevance of polyimide membranes for pervaporation process. The data of self diffusion coefficient produced by the predictive version of free-volume theory after Vrentas and Duda, was compared with the data produced via coupled molecular dynamic simulation for the water and ethanol penetrants, showing the relevance of both theories for the prediction of penetrants kinetic in complex polymeric matrixes
Doutorado
Ciencia e Tecnologia de Materiais
Doutor em Engenharia Química
Flores, Livas José. "Computational and experimental studies of sp3-materials at high pressure." Thesis, Lyon 1, 2012. http://www.theses.fr/2012LYO10127.
Full textWe present experimental and theoretical studies of sp3 materials, alkaline-earth-metal (AEM) disilicides, disilane (Si2H6) and carbon at high pressure. First, we study the AEM disilicides and in particular the case of a layered phase of BaSi2 which has an hexagonal structure with sp3 bonding of the silicon atoms. This electronic environment leads to a natural corrugated Si-sheets. Extensive ab initio calculations based on DFT guided the experimental research and permit explain how electronic and phonon properties are strongly affected by changes in the buckling of the silicon plans. We demonstrate experimentally and theoretically an enhancement of superconducting transition temperatures from 6 to 8.9 K when silicon planes flatten out in this structure. Second, we investigated the crystal phases of disilane at the megabar range of pressure. A novel metallic phase of disilane is proposed by using crystal structure prediction methods. The calculated transition temperatures yielding a superconducting Tc of around 20 K at 100 GPa and decreasing to 13 K at 220 GPa. These values are significantly smaller than previously predicted Tc’s and put serious drawbacks in the possibility of high-Tc superconductivity based on silicon-hydrogen systems. Third, we studied the sp3-carbon structures at high pressure through a systematic structure search. We found a new allotrope of carbon with Cmmm symmetry which we refer to as Z-carbon. This phase is predicted to be more stable than graphite for pressures above 10 GPa and is formed by sp3-bonds. Experimental and simulated XRD, Raman spectra suggest the existence of Z-carbon in micro-domains of graphite under pressure
Lin, Chieh. "Imagerie fonctionelle corps entier dans les hémopathies lymphoïdes." Thesis, Paris Est, 2009. http://www.theses.fr/2009PEST0053.
Full textThree components regarding whole-body functional imaging in lymphoid malignancies have been studies in this thesis. We first demonstrated retrospectively in a series of 92 patients with diffuse large B-cell lymphoma (DLBCL) that 14 patients (15%) considered as positive on visual analysis on FDG-PET after only 2 cycles of chemotherapy could have been correctly re-classified as good responders by measuring the percentage reduction of maximum standardized uptake value (SUVmax); in a subgroup of 80 patients, SUV-based assessment was equivalent to visual analysis at 4 cycles for patient outcome prediction. We secondly developed a whole-body 5-station dynamic contrast- enhanced MR protocol and time-signal intensity curves for the bone marrow and the focal lesions were successfully obtaines in 21 patients with plasma cell disorders included in the feasibility study; later in a pilot prospective study with 30 patients with multiple myeloma who received systemic therapy, we showed that this novel whole-body functional MR technique can be used to assess treatment response and helps to delect residual active disease after completion of therapy when clinically no or only minimum monoclonal protein can be identified. We thirdly optimized a whole-body diffusion-weighted MR protocol with respiratory gating in order to determine apparent diffusion coefficient (ADC) value on a whole-body scale. Pilot study was performed in 15 patients with DLBCL for both staging and response assessment at 4 cycles of chemotherapy, with FDG PET/CT as the standard of reference
Liu, Qingfeng. "Multi-phase modelling of multi-species ionic migration in concrete." Thesis, University of Plymouth, 2014. http://hdl.handle.net/10026.1/3133.
Full textElkin, Lauren S. "Predicting Diffusion of Contagious Diseases Using Social Media Big Data." Case Western Reserve University School of Graduate Studies / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=case1408978084.
Full textVasseur, Julien. "Fiabilité prévisionnelle de la tenue en service de composants mécaniques en présence d’amas de porosités détectés et caractérisés par contrôle non destructif ultrasonore." Thesis, Ecole nationale supérieure Mines-Télécom Lille Douai, 2020. http://www.theses.fr/2020MTLD0002.
Full textThis work aims at defining a methodology for the lifetime estimation of aluminum alloy structures (aluminum 7075-T6) according to the properties of porosity clusters contained in the sample. We chose to use advanced ultrasonic imaging techniques to detect and characterize these porosities and then to correlate the ultrasonic images obtained with fatigue measurements. In the framework of our study, the problem is simplified with a 2D study where the cluster of porosities is represented as a set of side-drilled holes (SDH) whose geometric characteristics are fully controllable, unlike those of real porosity. A special effort is made to estimate the effects of multiple scattering due to wave interactions between defects. A comparative study of the imaging model thus developed is carried out by comparing our simulations including multiple scattering with other simplified simulation results (carried out on CIVA software) but also with experimental measurements. Concerning fatigue study, a phenomenological approach is suggested to take into account multi-cracks initiation and local multi-mode behaviour generated by the cluster of defects. Therefore, crack propagation is solved by a G-Ө finite element method for prediction of the fatigue lifetime of different samples with different cases of cluster of defects. Numerical and experimental results were compared showing that the suggested methodology gives realistic lifetimes despite of complexity of the studied cases. Finally, the overall originality of this thesis consists in making a direct link between NDT results and fatigue calculation. Thus, a method for estimating the fatigue life of a specimen based on inversed ultrasonic images of defects is suggested and applied on some studied cases
Gambrell, Stefphanie Michelle. "Predicting the life cycle of rice varieties in Texas." Texas A&M University, 2004. http://hdl.handle.net/1969.1/3069.
Full textPatton, Daya. "Predictive Relationships Between School Counselor Role Ambiguity, Role Diffusion, and Job Satisfaction." ScholarWorks, 2019. https://scholarworks.waldenu.edu/dissertations/6260.
Full textTepesch, Patrick David. "Atomistic modeling of ceramic materials : predicting crystal structures, thermodynamic properties, and diffusion behavior." Thesis, Massachusetts Institute of Technology, 1996. http://hdl.handle.net/1721.1/10936.
Full textJiang, Jieyi Jiang. "Realistic Predictive Risk: The Role of Penalty and Covariate Diffusion in Model Selection." The Ohio State University, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=osu1503072235693181.
Full textMechelli, Luca [Verfasser]. "POD-based State-Constrained Economic Model Predictive Control for Convection-Diffusion Phenomena / Luca Mechelli." Konstanz : KOPS Universität Konstanz, 2019. http://d-nb.info/1200355075/34.
Full textWitty, Tricia. "An evaluation of molecular weight predictions in emulsion polymerization under conditions of diffusion limited chain transfer." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/MQ59411.pdf.
Full textWu, Ona. "Predictive models of tissue outcome in acute human cerebral ischemia using diffusion and perfusion weighted MRI." Thesis, Massachusetts Institute of Technology, 2002. http://hdl.handle.net/1721.1/8358.
Full textIncludes bibliographical references.
Diffusion (DWI) and perfusion weighted (PWI) magnetic resonance imaging (MRI) provide significant insight into acute stroke and can potentially be useful for clinical decision-making. In particular, current therapeutic decisions for acute human cerebral ischemia are typically based on time of symptom onset, limiting the number of patients treated. Imaging, however, offers insight into the physiologic integrity of brain tissue that is not attainable with time of symptom onset alone. This thesis extends existing imaging techniques for acute human stroke in order to improve identification of tissue at risk of infarction, thereby assisting clinical decision-making at the stage when intervention may be most effective. DWI and PWI have both been shown to identify infarcted tissue earlier than conventional stroke imaging. However, these techniques are limited in their existing implementations. DWI in most acute stroke settings has been restricted to isotropic imaging, measuring only mean diffusivity. In this thesis, DWI is extended to diffusion tensor imaging (DTI) with results demonstrating that DTI can detect ultrastructural changes in acute human stroke. PWI measures perfusion status by tracking the first pass of a bolus of contrast agent. In this dissertation, using numerical simulations, delay in contrast agent arrival is found to result in biased estimates of perfusion indices. A deconvolution technique using a block-circulant matrix is therefore proposed to compensate for delayed arrival, and its performance is compared to non-block circulant techniques in simulations as well as in clinically acquired human data sets.
(cont.) The results show that decoupling delay-associated effects reduces bias in tissue perfusion estimates. Algorithms combining DWI and PWI information are also evaluated to determine whether they predict tissue outcome in acute stroke better than models using only subsets of these parameters. Results show that algorithms combining DWI and PWI on a voxel-by-voxel basis predict tissue that infarct with higher specificity and sensitivity than algorithms using DWI or PWI individually. These combination algorithms are then used to investigate the efficacy of a novel therapeutic agent by evaluating the performance of the model as a function of treatment dose. Findings suggest that predictive models allow evaluation of novel therapies using smaller sample sizes than traditional endpoints. The results of this dissertation demonstrate that imaging can be used to identify tissue at risk of infarction, which may aid diagnosis and prognosis by providing clinicians unique insight into the underlying pathophysiology of stroke.
by Ona Wu.
Ph.D.
Heesen, Bernd. "Diffusion of innovations : factors predicting the use of e-learning at institutions of higher education in Germany." Berlin dissertation.de, 2006. http://deposit.d-nb.de/cgi-bin/dokserv?id=2833665&prov=M&dokv̲ar=1&doke̲xt=htm.
Full textHeesen, Bernd. "Diffusion of innovations factors predicting the use of e-learning at institutions of higher education in Germany." Berlin dissertation.de, 2004. http://deposit.d-nb.de/cgi-bin/dokserv?id=2833665&prov=M&dok_var=1&dok_ext=htm.
Full textUznanski, Przemyslaw. "Large scale platform : Instantiable models and algorithmic design of communication schemes." Phd thesis, Université Sciences et Technologies - Bordeaux I, 2013. http://tel.archives-ouvertes.fr/tel-00878837.
Full textZhou, Xueqing. "Predicting Solute Transport in Natural Streams - A Stochastic Approach." PDXScholar, 1994. https://pdxscholar.library.pdx.edu/open_access_etds/5057.
Full textHoang, Thi Bich Ngoc. "Information diffusion, information and knowledge extraction from social networks." Thesis, Toulouse 2, 2018. http://www.theses.fr/2018TOU20078.
Full textThe popularity of online social networks has rapidly increased over the last decade. According to Statista, approximated 2 billion users used social networks in January 2018 and this number is still expected to grow in the next years. While serving its primary purpose of connecting people, social networks also play a major role in successfully connecting marketers with customers, famous people with their supporters, need-help people with willing-help people. The success of online social networks mainly relies on the information the messages carry as well as the spread speed in social networks. Our research aims at modeling the message diffusion, extracting and representing information and knowledge from messages on social networks. Our first contribution is a model to predict the diffusion of information on social networks. More precisely, we predict whether a tweet is going to be diffused or not and the level of the diffusion. Our model is based on three types of features: user-based, time-based and content-based features. Being evaluated on various collections corresponding to dozen millions of tweets, our model significantly improves the effectiveness (F-measure) compared to the state-of-the-art, both when predicting if a tweet is going to be retweeted or not, and when predicting the level of retweet. The second contribution of this thesis is to provide an approach to extract information from microblogs. While several pieces of important information are included in a message about an event such as location, time, related entities, we focus on location which is vital for several applications, especially geo-spatial applications and applications linked to events. We proposed different combinations of various existing methods to extract locations in tweets targeting either recall-oriented or precision-oriented applications. We also defined a model to predict whether a tweet contains a location or not. We showed that the precision of location extraction tools on the tweets we predict to contain a location is significantly improved as compared when extracted from all the tweets.Our last contribution presents a knowledge base that better represents information from a set of tweets on events. We combined a tweet collection with other Internet resources to build a domain ontology. The knowledge base aims at bringing users a complete picture of events referenced in the tweet collection (we considered the CLEF 2016 festival tweet collection)
Nguyen, Cu Ngoc. "Stochastic differential equations with long-memory input." Thesis, Queensland University of Technology, 2001.
Find full textMalmaeus, Jan Mikael. "Predictive Modeling of Lake Eutrophication." Doctoral thesis, Uppsala University, Department of Earth Sciences, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-4625.
Full textThis thesis presents predictive models for important variables concerning eutrophication effects in lakes. The keystone is a dynamic phosphorus model based on ordinary differential equations. By calculating mass fluxes of phosphorus into, within and out from a lake, the concentrations of different forms of phosphorus in different compartments of the lake are estimated.
The dynamic phosphorus model is critically tested and several improvements are presented, including two new compartments for colloidal phosphorus, a sub-model for suspended particulate matter (SPM) and new algorithms for lake outflow, water mixing, diffusion, water content and organic content of accumulation sediments are implemented. Predictions with the new version show good agreement against empirical data in five tested lakes.
The sub-model for SPM uses the same driving variables as the basic phosphorus model, so the inclusion of this model as a sub-model does not require any additional variables. The model for SPM may also be used as a separate model giving monthly predictions of suspended particulate matter in two water compartments and one compartment with SPM available for resuspension in ET-sediments.
Empirical data from Lake Erken (Sweden) and Lake Balaton (Hungary) are used to evaluate the variability in settling velocity of SPM. It is found that the variability is substantial and may be accounted for by using a dimensionless moderator for SPM concentration. Empirical data from accumulation area sediments in Lake Erken are used to develop a model for the dynamics of phosphorus sedimentation, burial and diffusion in the sediments. The model is shown to provide reasonable monthly predictions of four functional forms of phosphorus at different sediment depths.
Simulations with the lake phosphorus model using two different climate scenarios indicate that lakes may respond very differently to climate change depending on their physical character. Lake Erken, with a water retention time of 7 years, appears to be much more sensitive than two basins of Lake Mälaren (Sweden) with substantially shorter retention times. The implication would be that in eutrophic lakes with long water retention times, eutrophication problems may become serious if the future becomes warmer. This will be important in contexts of lake management when remedial measures against lake eutrophication have to be taken.
Guille, Adrien. "Diffusion de l’information dans les médias sociaux : modélisation et analyse." Thesis, Lyon 2, 2014. http://www.theses.fr/2014LYO22015/document.
Full textSocial media have greatly modified the way we produce, diffuse and consume information, and have become powerful information vectors. The goal of this thesis is to help in the understanding of the information diffusion phenomenon in social media by providing means of modeling and analysis.First, we propose MABED (Mention-Anomaly-Based Event Detection), a statistical method for automatically detecting events that most interest social media users from the stream of messages they publish. In contrast with existing methods, it doesn't only focus on the textual content of messages but also leverages the frequency of social interactions that occur between users. MABED also differs from the literature in that it dynamically estimates the period of time during which each event is discussed rather than assuming a predefined fixed duration for all events. Secondly, we propose T-BASIC (Time-Based ASynchronous Independent Cascades), a probabilistic model based on the network structure underlying social media for predicting information diffusion, more specifically the evolution of the number of users that relay a given piece of information through time. In contrast with similar models that are also based on the network structure, the probability that a piece of information propagate from one user to another isn't fixed but depends on time. We also describe a procedure for inferring the latent parameters of that model, which we formulate as functions of observable characteristics of social media users. Thirdly, we propose SONDY (SOcial Network DYnamics), a free and extensible software that implements state-of-the-art methods for mining data generated by social media, i.e. the messages published by users and the structure of the social network that interconnects them. As opposed to existing academic tools that either focus on analyzing messages or analyzing the network, SONDY permits the joint analysis of these two types of data through the analysis of influence with respect to each detected event.The experiments, conducted on data collected on Twitter, demonstrate the relevance of our proposals and shed light on some properties that give us a better understanding of the mechanisms underlying information diffusion. First, we compare the performance of MABED against those of methods from the literature and find that taking into account the frequency of social interactions between users leads to more accurate event detection and improved robustness in presence of noisy content. We also show that MABED helps with the interpretation of detected events by providing clearer textual description and more precise temporal descriptions. Secondly, we demonstrate the relevancy of the procedure we propose for estimating the pairwise diffusion probabilities on which T-BASIC relies. For that, we illustrate the predictive power of users' characteristics, and compare the performance of the method we propose to estimate the diffusion probabilities against those of state-of-the-art methods. We show the importance of having non-constant diffusion probabilities, which allows incorporating the variation of users' level of receptivity through time into T-BASIC. We also study how -- and in which proportion -- the social, topical and temporal characteristics of users impact information diffusion. Thirdly, we illustrate with various scenarios the usefulness of SONDY, both for non-experts -- thanks to its advanced user interface and adapted visualizations -- and for researchers -- thanks to its application programming interface