Дисертації з теми "Graded density"
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McConaha, Matthew. "Graded Lattice Structure Density Optimization for Additive Manufacturing." University of Cincinnati / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1523634949822303.
Повний текст джерелаYao, Jiaolian. "DENSITY GRADED LMDPE FOAMS PRODUCED UNDER A TEMPERATURE GRADIENT: MORPHOLOGY AND PROPERTIES." Thesis, Université Laval, 2011. http://www.theses.ulaval.ca/2011/28072/28072.pdf.
Повний текст джерелаIn this work, linear medium density polyethylene (LMDPE) and Expancel microbeads were used to produce density graded polymer foams using compression molding. By controlling independently the top and bottom plate temperatures in the mold, different temperatures and molding times were used to produce symmetric and asymmetric foams. The effect of blowing agent type and content were also studied to control the density profile and foam morphology (cell size and cell density) across thickness. Finally, the mechanical behavior in flexion and tension is reported and discussed in relation with foam morphology and structure.
Bajaj, Sanyam. "Design and Engineering of AlGaN Channel-Based Transistors." The Ohio State University, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=osu1514904566666781.
Повний текст джерелаJoseph, Roy. "Development of an injection moulding grade hydroxyapatite polyethylene composite." Thesis, Queen Mary, University of London, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.395936.
Повний текст джерелаParrondo, Aitor. "Optimisation and mode of action of antioxidant stabilisation in film grade high-density polyethylene." Thesis, Manchester Metropolitan University, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.366053.
Повний текст джерелаNguyen, Minh-Lien Jeanne. "Estimation non paramétrique de densités conditionnelles : grande dimension, parcimonie et algorithmes gloutons." Thesis, Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLS185/document.
Повний текст джерелаWe consider the problem of conditional density estimation in moderately large dimen- sions. Much more informative than regression functions, conditional densities are of main interest in recent methods, particularly in the Bayesian framework (studying the posterior distribution, find- ing its modes...). After recalling the estimation issues in high dimension in the introduction, the two following chapters develop on two methods which address the issues of the curse of dimensionality: being computationally efficient by a greedy iterative procedure, detecting under some suitably defined sparsity conditions the relevant variables, while converging at a quasi-optimal minimax rate. More precisely, the two methods consider kernel estimators well-adapted for conditional density estimation and select a pointwise multivariate bandwidth by revisiting the greedy algorithm RODEO (Regular- isation Of Derivative Expectation Operator). The first method having some initialization problems and extra logarithmic factors in its convergence rate, the second method solves these problems, while adding adaptation to the smoothness. In the penultimate chapter, we discuss the calibration and nu- merical performance of these two procedures, before giving some comments and perspectives in the last chapter
Locke, Shawn Lee. "Estimating Rio Grande wild turkey densities in Texas." Thesis, [College Station, Tex. : Texas A&M University, 2007. http://hdl.handle.net/1969.1/ETD-TAMU-1970.
Повний текст джерелаIkwut-Ukwa, Udungs Henry. "Advances in vehicle emissions modeling : development of a methodology for the kinematic acquisition of roadway grade data." Diss., Georgia Institute of Technology, 2001. http://hdl.handle.net/1853/20843.
Повний текст джерелаDändliker, Thomas. "Optimisation de la densité de reboisement en fonction des grades de qualité des bois sciés." Master's thesis, Université Laval, 2021. http://hdl.handle.net/20.500.11794/69047.
Повний текст джерелаSebbar, Mehdi. "On unsupervised learning in high dimension." Thesis, Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLG003/document.
Повний текст джерелаIn this thesis, we discuss two topics, high-dimensional clustering on the one hand and estimation of mixing densities on the other. The first chapter is an introduction to clustering. We present various popular methods and we focus on one of the main models of our work which is the mixture of Gaussians. We also discuss the problems with high-dimensional estimation (Section 1.3) and the difficulty of estimating the number of clusters (Section 1.1.4). In what follows, we present briefly the concepts discussed in this manuscript. Consider a mixture of $K$ Gaussians in $RR^p$. One of the common approaches to estimate the parameters is to use the maximum likelihood estimator. Since this problem is not convex, we can not guarantee the convergence of classical methods such as gradient descent or Newton's algorithm. However, by exploiting the biconvexity of the negative log-likelihood, the iterative 'Expectation-Maximization' (EM) procedure described in Section 1.2.1 can be used. Unfortunately, this method is not well suited to meet the challenges posed by the high dimension. In addition, it is necessary to know the number of clusters in order to use it. Chapter 2 presents three methods that we have developed to try to solve the problems described above. The works presented there have not been thoroughly researched for various reasons. The first method that could be called 'graphical lasso on Gaussian mixtures' consists in estimating the inverse matrices of covariance matrices $Sigma$ (Section 2.1) in the hypothesis that they are parsimonious. We adapt the graphic lasso method of [Friedman et al., 2007] to a component in the case of a mixture and experimentally evaluate this method. The other two methods address the problem of estimating the number of clusters in the mixture. The first is a penalized estimate of the matrix of posterior probabilities $ Tau in RR ^ {n times K} $ whose component $ (i, j) $ is the probability that the $i$-th observation is in the $j$-th cluster. Unfortunately, this method proved to be too expensive in complexity (Section 2.2.1). Finally, the second method considered is to penalize the weight vector $ pi $ in order to make it parsimonious. This method shows promising results (Section 2.2.2). In Chapter 3, we study the maximum likelihood estimator of density of $n$ i.i.d observations, under the assumption that it is well approximated by a mixture with a large number of components. The main focus is on statistical properties with respect to the Kullback-Leibler loss. We establish risk bounds taking the form of sharp oracle inequalities both in deviation and in expectation. A simple consequence of these bounds is that the maximum likelihood estimator attains the optimal rate $((log K)/n)^{1/2}$, up to a possible logarithmic correction, in the problem of convex aggregation when the number $K$ of components is larger than $n^{1/2}$. More importantly, under the additional assumption that the Gram matrix of the components satisfies the compatibility condition, the obtained oracle inequalities yield the optimal rate in the sparsity scenario. That is, if the weight vector is (nearly) $D$-sparse, we get the rate $(Dlog K)/n$. As a natural complement to our oracle inequalities, we introduce the notion of nearly-$D$-sparse aggregation and establish matching lower bounds for this type of aggregation. Finally, in Chapter 4, we propose an algorithm that performs the Kullback-Leibler aggregation of components of a dictionary as discussed in Chapter 3. We compare its performance with different methods: the kernel density estimator , the 'Adaptive Danzig' estimator, the SPADES and EM estimator with the BIC criterion. We then propose a method to build the dictionary of densities and study it numerically. This thesis was carried out within the framework of a CIFRE agreement with the company ARTEFACT
Zou, Aihong. "Uncertainty quantification in high-density fluid radial-inflow turbo-expanders and diffusers for renewable low-grade temperature cycles." Thesis, Queensland University of Technology, 2019. https://eprints.qut.edu.au/128481/1/Aihong_Zou_Thesis.pdf.
Повний текст джерелаSchmidt, Joel Edward. "The Use of Ammonium Carbamate as a High Specific Thermal Energy Density Material for Thermal Management of Low Grade Heat." University of Dayton / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1310666985.
Повний текст джерелаHolveck, Susan, and Susan Holveck. "Teaching for Conceptual Change in a Density Unit Taught to 7th Graders: Comparing Two Teaching Methodologies - Scientific Inquiry and a Traditional Approach." Thesis, University of Oregon, 2012. http://hdl.handle.net/1794/12414.
Повний текст джерелаNguessong, Nkenfack Alain. "Modélisation ds matériaux caoutchouteux par une nouvelle densité hyperélastique isotrope hybride - Théorie et implémentation éléments finis." Thesis, Belfort-Montbéliard, 2015. http://www.theses.fr/2015BELF0257/document.
Повний текст джерелаThis thesis concerns the development of a new incompressible isotropic hyperelastic behavior law allowing the modeling of rubber materials with large strain and large displacement. This new law mixes a molecular approach with a phenomenological one and therefore covers a wide range of loading. It has been built by a sum over four terms:– a term related to the interleaving macromolecular chains observed with the crystallization phenomenon. This term is modeled by a logarithmic function coming from the phenomenological energy of Gent-Thomas,– a term related to the assumption of affine deformations observed with the final stiffening of a part of macromolecular elastomeric chains. This term comes from the non Gaussian probability of Langevin. We have modeled it by the 8-chains molecular law of Arruda-Boyce but with an original approximation of the inverse of the Langevin function,– a term related to the stress occurring with non affine strains. This term has been modeled by a Gaussian function adopting an integral form. This is one of the original contribution of this thesis work,– a classical volumetric term taking into account the incompressibility of the material.The two main originalities of the thesis are therefore the introduction of a new approximation of the inverse of the Langevin function and the development of a new hyperelastic energy density which is isotropic, incompressible and hybrid.In order to study the efficiency of the proposed model, comparisons were made with several experimental data available in the literature. These comparisons have been successful and we have implemented our model in the university finite element software FER
Laia, Rafael Camilo. "Dinâmica dos girinos e caracterização da larva do anuro endêmico Hylodes fredi (ANURA: HYLODIDAE) na Mata Atlântica da Ilha Grande, Rio de Janeiro." Universidade do Estado do Rio de Janeiro, 2010. http://www.bdtd.uerj.br/tde_busca/arquivo.php?codArquivo=1866.
Повний текст джерелаHylodes fredi é um anfíbio anuro endêmico da Mata Atlântica da Ilha Grande, estado do Rio de Janeiro. Os girinos desta rã são encontrados nos remansos dos córregos de floresta de águas límpidas, substrato rochoso e em áreas de água rasa, onde os machos adultos podem ser visualizados em atividade de canto. Buscando aumentar a compreensão da dinâmica populacional das larvas de H. fredi, comparamos suas ocorrência, densidade e condição energética em quatro córregos na porção sul da Ilha Grande em um período de doze meses, relacionando inclusive com parâmetros físico-químicos da água. A condição energética foi calculada como o resíduo da relação entre o logaritmo natural da massa e o logaritmo natural do comprimento do corpo de todas as larvas amostradas desta espécie. A densidade e a condição energética dos girinos de H. fredi variaram entre os córregos. Todas as variáveis da água medidas (oxigênio dissolvido, condutividade, temperatura e profundidade), com exceção do pH, influenciaram na diferenciação entre os córregos. A ocorrência de girinos de diferentes tamanhos e massas ao longo de todos os meses, sem uma clara tendência de crescimento sazonal, sugere que H. fredi possui um extenso período reprodutivo durante todo o ano. Tanto os fatores ambientais da água quanto as densidades dos girinos de H. fredi diferenciaram entre as mesmas áreas. Entretanto não houve diferenciação coincidente na condição energética das larvas de H. fredi e nos fatores abióticos entre os mesmos córregos. As diferen as nas densidades e nas condições energéticas médias dos girinos de H. fredi entre as estações seca e chuvosa sugerem que as condições do ambiente são mais apropriadas na estação chuvosa, com uma maior disponibilidade de recursos. As larvas de H. fredi vivendo em córregos com maiores densidades de girinos da família Hylodidae (H. fredi e Crossodactylus gaudichaudii) possuem, em média, condição energética mais reduzida. Isso provavelmente pode ser explicado pelo compartilhamento de recursos, uma vez que, quando limitados, estes seriam mais escassos para cada indivíduo. A densidade de girinos de H. fredi foi mais influenciada por fatores físico-químicos do ambiente enquanto a condição energética dessas larvas foi mais influenciada por fatores biológicos do ambiente. Assim, os girinos de H. fredi variam na densidade e na condição energética como resultado de um balanço entre os parâmetros bióticos e abióticos dos córregos em que as larvas ocorrem. Neste trabalho, nós também descrevemos o girino de H. fredi.
Hylodes fredi is an endemic frog from Ilha Grande, an Atlantic Forest island, located in Rio de Janeiro state, southeast Brazil. The tadpoles of this species are found in clear stream backwaters in the forest, rocky substrate, in shallow waters where calling male frogs can be found. In order to improve the population dynamic knowledge of H. fredi larval stage, we compared their occurrence, density and energetic condition in four streams from the south portion of Ilha Grande in twelve months, relating them to the physicochemical parameters of the water. Energetic condition was calculated as residual of the relationship between the natural logarithm of mass and the natural logarithm of body length of all the H. fredi tadpoles sampled. Density and condition of the H. fredi larvaes varied between the streams. All variables of water measured (dissolved oxygen, conductivity, temperature and depth), except for pH, influenced the discrimination between the streams. The occurrence of tadpoles with different sizes and masses in all the months, without a clear seasonal variation, suggests that H. fredi has an extensive reproductive period along the year. Both environmental factors of the water and H. fredi tadpoles densities were different between the same streams. However, the energetic condition of the larvaes and the abiotic factors did not differentiated between the same streams. The differences found in density and energetic condition of H. fredi tadpoles between dry and wet seasons indicate that environmental conditions are more appropriate in the wet season, with greater availability of resources. Hylodes fredi larvaes living in streams with higher densities of Hylodidae tadpoles (H. fredi and Crossodactylus gaudichaudii) have smaller energetic condition values. This result seems to be probably due to the sharing of the limited resources, once these would be scarcer for each individual. Density of H. fredi tadpoles was more influenced by the physicochemical factors of the environment, while energetic condition of these tadpoles was more influenced by the biological factors of the environment. Then, density and energetic condition of H. fredi tadpoles vary in result of a balance between the abiotic and biotic parameters of the streams in which the larvaes occur. In this study, we also describe the tadpole of H. fredi.
Dechamps, Yves. "Méthode d'analyse des risques majeurs liés aux immeubles de grande hauteur sur leur environnement immédiat." Doctoral thesis, Universite Libre de Bruxelles, 2013. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/209500.
Повний текст джерелаLa conception d'un IGH ne peut être effectuée sans une analyse des risques engendrés par la présence de tels immeubles sur leur environnement et sur le développement urbain. En effet, quand un événement indésirable y survient, un IGH peut se révéler être une menace pour ses occupants et son
voisinage immédiat. Les IGH sont des immeubles où plusieurs centaines de personnes sont présentes, ce qui engendre de nombreuses contraintes au niveau de la sécurité incendie notamment. En cas d'accident comme un incendie, diverses matières toxiques peuvent être libérées dans l'atmosphère, endommageant l'environnement de l'immeuble.
C'est ici que peut intervenir une méthode d'analyse des risques environnementaux permettant à un expert d'évaluer différentes situations envisagées pour l'immeuble même et son environnement. Le modèle proposé est une nouvelle méthode quantitative issue d'une approche semi-quantitative. Des matrices d'évaluation et une formulation quantitative permettent de quantifier le risque environnemental. Ce risque est déterminé pour différents secteurs autour de l'IGH car chaque environnement étudié est hétérogène et différent.
La méthode proposée reprend un ensemble de paramètres déterminés à l'aide de critères d'évaluation et de paramètres géométriques tels que la différence d'altitude entre les immeubles, la distance, etc. Nous verrons comment ces paramètres influencent le modèle et l'analyse de risques environnementaux. Un ensemble de simulations numériques seront effectuées sur un panel de cas d'études simples afin de valider le programme. Deux IGH actuellement détruits ont été étudiés avec pour objectif de comparer les résultats obtenus avec la réalité de la situation ainsi que les différentes propositions correctives. Pour chaque étude, des critiques et commentaires seront produits afin de se rattacher à la réalité des situations décrites.
The high-rise buildings (HRB) are symbolic constructions linked most often to scarce building lands, urban density challenges for big cities and the problematic of sustainable construction. However, an HRB is not limited to just these items alone: what risk impact does an HRB have on the environment? What analysis method of possible risk on the environment is to be considered for the presence of constructions?
HRB design cannot be done without any environmental risk assessment for such buildings on their environment or their impact on urban development. When an unwanted event occurs, an HRB can be a threat to its occupants and its immediate vicinity. The presence of large numbers of people in those building definitely generates a lot of problems at the level of fire safety, for example. Accidents such as a fire can release toxic materials, which will thus impact the environment of the building.
In such circumstances, a method of analysis of environmental risks come useful to experts to assess the different situations to be considered for the building itself. The proposed model is a new quantitative method which is the result of a semi-quantitative approach. Quantifying the environmental risk is made possible by evaluation matrices and quantitative formulation. This risk is determined for various sectors around HRB because every environment is heterogeneous and different.
The proposed method incorporates a set of parameters which were determined by means of evaluation criteria and geometrical parameters such as the difference in height between the buildings, distance, etc. We will see how these parameters affect the model and analysis of environmental risks. A set of simulations are performed on a range of simple models to validate the program. Two HRBs which have now been demolished were studied so as to compare the results obtained with the real-life of the situation and the corrective different proposals. For each study, criticism and comments will be produced to relate to the reality of the situations which has been described.
Doctorat en Sciences de l'ingénieur
info:eu-repo/semantics/nonPublished
Lei, Liangzhen. "Grandes déviations pour les estimateurs à noyau de la densité et étude de l'estimateur de décrément aléatoire." Phd thesis, Université Blaise Pascal - Clermont-Ferrand II, 2005. http://tel.archives-ouvertes.fr/tel-00011959.
Повний текст джерелаLe premier thème est la partie principale de cette thèse, constituées des quatre premiers chapitres. Dans le chapitre 1, on établit le w*-PGD(principe de grandes déviations) de $f_n^*$ et une inégalité de concentration dans le cas i.i.d.. On démontre dans le chapitre 2 la convergence exponentielle de $f_n^*$ dans $L^1(R^d)$ et une inégalité de concentration pour des suites $\phi$-mélangeants, en se basant sur une inégalité de tranport de Rio. Les chapitre 3 et 4 constituent le coeur de cette thèse : on établit (i) le PGD de $f_n^*$ pour la topologie faible $\sigma(L^1, L^{\infty})$ ; (ii) le w*-PGD de $f_n^*$ dans $L^1$ pour la topologie forte $\vert\cdot\vert_1$ ; (iii) l'estimation de grandes déviations pour l'erreur $D_n^*=\vert f_n^*(x)-f(x) \vert_1$ et (iv) l'optimalité asymptotique de $f_n^*$ au sens de Bahadur. Ces résultats sont prouvés dans le chapitre 3 pour des processus de Markov uniformément ergodiques et dans le chapitre 4 pour des processus de Markov réversibles uniformément intégrables.
Le dernier chapitre est consacré au second thème. On démontre la loi des grands nombres et le théorème de limite centrale pour l'EDA à temps discret et on établit pour la première fois l'expression explicite du biais de l'EDA à temps continu.
Ammar, Sourour. "Modèles Graphiques Probabilistes pour l'Estimation de Densité en grande dimension : applications du principe Perturb & Combine pour les mélanges d'arbres." Phd thesis, Université de Nantes, 2010. http://tel.archives-ouvertes.fr/tel-00568136.
Повний текст джерелаHentschke, Guilherme Scotta. "Chlorococcales latu sensu(Chlorophyceae) em ambientes aquáticos na planície costeira do Rio Grande do Sul, Brasil : taxonomia, distribuição e aspectos ecológicos." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2009. http://hdl.handle.net/10183/30825.
Повний текст джерелаThis paper is about the Desmodesmus An, Friedl & Hegew. and Scenedesmus Meyen flora, found at isolated ponds, interlinked ponds, swamps, dams and lotic environments, at the Coastal Plain of Rio Grande do Sul. The taxonomic composition and how richness and density relate to the variables temperature and pH were evaluated. The study was based on 41 samplings collected in autumn and spring of 2003. A total of 14 species and two varieties of Desmodesmus, and two species and a variety of Scenedesmus were identified. Four new combinations (Desmodesmus granulatus (W.& G. S. West. ) Hentschke & Torgan, Desmodesmus heteracanthus (Guerr.) Hentschke & Torgan, Desmodesmus microspina (Chod.) Hentschke & Torgan and Desmodesmus spinosoaculeolatus (Chod.) Hentschke & Torgan) were proposed. The statistical analysis revealed that the variation of richness and density were influenced by pH (r2 = 0,53 e r2= 0,97). Comparing autumn and spring, it is observed that the density average (ind. mL-1) of Desmodesmus and Scenedesmus in spring differs significantly of the average obtained in the autumn (p = 0,04) and, comparing the richness averages, that the average of the litoral zones differs significantly of the average obtained in the pelagic zones (p = 0,02).
Mahmoud, Rihab. "Development and Application of an Eulerian Density Function Methodology coupled to Flamelet Progress Variable Approach for the Simulation of Oxyfuel Combustion." Thesis, université Paris-Saclay, 2020. http://www.theses.fr/2020UPAST019.
Повний текст джерелаIn the prevailing situation of unsustainable fossil fuel resources and the elevated levels of air pollutant emissions, the state-of-the-art of combustion investigations confronts primarily two challenges. These are on the one hand the optimization of the fossil fuel combustion efficiency and on the other hand the development and the application of robust strategies to reduce the amount of the released pollutant gases with respect to the new emission standards in accordance with the global energy policies.Within this context, the carbon dioxide capture and storage (CCS) technologies play an important role as an accepted strategy towards the mitigation of CO 2 emissions. One of the important aspects of the CCS techniques is the oxidation of natural gas under oxy-fuel combustion conditions. However, very few scientific contributions have been devoted to the research of these systems, so that there is a lack of understanding of the oxy-combustion processes.The present work aims at the development and the application of an advanced numerical approach for the simulation of oxy-fuel combustion in which the TCI is adequatelyaccounted for within non-premixed combustion regimes using the OpenFOAM platform.The suggested model which is designed for both RANS and LES applications consists of a combination of a transported probability density function approach following the Eulerian Stochastic field methodology and the flamelet progress variable (FPV) chemistry reduction mechanism. In the LES framework, the proposed method accurately represents the effect of the sub-grid fluctuations on the flame structure and on combustion characteristics along with the interaction between turbulence and chemistry.The implemented developed combustion model is first verified, and then validated and applied to different turbulent non-premixed combustion configurations featuring an increasing order of complexity. In particular, Sandia flame D which consists of a turbulent piloted methane-air jet flame is first employed for model validation in both RANS and LES contexts. The next flames are more challenging cases, namely the non-premixed Sandia oxy-flame series (A & B), which are operated under different Re numbers and characterized by various CO 2 and H 2 enrichments in the oxidizer and fuel streams, respectively. All investigated cases are well documented with available experimentalmeasurements.The comparison of the obtained results with experimental data in terms of temperature, scalar distributions, PDFs and scatter plots agree satisfactorily, essentially in the LES context.This work finally reveals that the hybrid ESF/FPV approach removes the weaknesses of the presumed probability density function based FPV modeling (β-PDF)
Freymark, Jessica Katja [Verfasser], Magdalena Akademischer Betreuer] Scheck-Wenderoth, and Klaus [Akademischer Betreuer] [Reicherter. "Implications of the 3D structural and density configuration for the thermal and hydraulic fields of the Upper Rhine Graben / Jessica Katja Freymark ; Magdalena Scheck-Wenderoth, Klaus Reicherter." Aachen : Universitätsbibliothek der RWTH Aachen, 2019. http://d-nb.info/1216040656/34.
Повний текст джерелаFreymark, Jessica Katja Verfasser], Magdalena [Akademischer Betreuer] Scheck-Wenderoth, and Klaus [Akademischer Betreuer] [Reicherter. "Implications of the 3D structural and density configuration for the thermal and hydraulic fields of the Upper Rhine Graben / Jessica Katja Freymark ; Magdalena Scheck-Wenderoth, Klaus Reicherter." Aachen : Universitätsbibliothek der RWTH Aachen, 2019. http://d-nb.info/1216040656/34.
Повний текст джерелаViau, Joël. "Développement et validation expérimentale d'un système d'embrayages magnétorhéologiques pour le contrôle de robot à tendons." Mémoire, Université de Sherbrooke, 2015. http://hdl.handle.net/11143/8055.
Повний текст джерелаKenzari, Hocine. "Structure électronique des composés à grande maille de type « chimney-ladder »." Vandoeuvre-les-Nancy, INPL, 1998. http://www.theses.fr/1998INPL121N.
Повний текст джерелаVarron, Davit. "Lois fonctionnelles limites uniformes pour les accroissements généralisésdu procesus empirique. Lois fonctionnelle limites de type Chung-Mogulskii pour le processus empirique uniforme local." Phd thesis, Université Pierre et Marie Curie - Paris VI, 2004. http://tel.archives-ouvertes.fr/tel-00008438.
Повний текст джерелаJonqueres, Jean-marie. "Génération de routage contraint en courant pour les applications analogiques forts courants." Thesis, Aix-Marseille, 2012. http://www.theses.fr/2012AIXM4768/document.
Повний текст джерелаIn deep submicron VLSI circuits, excessive current density in interconnects is a major concern for analog high current application. If current over maximum density is not effectively mitigated, this can lead to phenomena like electromigration, voltage drop and electrical overload. It is a hot topic of interest in modern circuits due to the decrease of metal track sizes while high currents are necessary in automotive or mobile applications. This thesis had as goal to develop solutions for the consideration of the constraints in the current phase of routing analog blocks strong currents. After a presentation of the phenomena and the state of the art, an algorithmic approach to current driven net generation is introduced. A method to characterize the current is defined. Then an exhaustive routing algorithm is presented and used to search criteria for a good topology. Next, two algorithms are studied and compared, first a greedy algorithm, used as a reference, and a "Divide & Conquer" original algorithm. It shows results improved on average by about 10% for area and almost 27% for CPU time compared with existing solution. The next section focuses on current crowding correction, with a method based on a set of mathematical models. Finally, a conception flow based on the developed solutions is introduced and validated
Guillois, Florian. "Analyse du transport turbulent dans une zone de mélange issue de l'instabilité de Richtmyer-Meshkov à l'aide d'un modèle à fonction de densité de probabilité : Analyse du transport de l’énergie turbulente." Thesis, Lyon, 2018. http://www.theses.fr/2018LYSEC020/document.
Повний текст джерелаThe aim of the thesis is to simulate a turbulent mixing zone resulting from the Richtmyer-Meshkov instability using a probability density function (PDF) model. An emphasis is put on the analysis of the turbulent kinetic energy transport.To this end, we first highlight the link existing between the one-point statistics of the flow and its initial conditions at large scales. This link is expressed through the principle of permanence of large eddies, and allows to establish predictions for quantities of the mixing zone, such as its growth rate or its anisotropy.We then derive a Langevin PDF model which is able to reproduce this dependency of the statistics on the initial conditions. This model is then validated by comparing it against large eddy simulations (LES).Finally, an asymptotic analysis of the derived model helps to improve our understanding of the turbulent transport. A diffusion regime is identified, and the expression of the diffusion coefficient associated with this regime confirms the influence of the permanence of large eddies on the turbulent transport.Throughout this thesis, our numerical results were based on Monte Carlo simulations for the Langevin model. In this regard, we proceeded to the development of a specific Eulerian method and its comparison with Lagrangian counterparts
Vedovoto, João Marcelo. "Mathematical and numerical modeling of turbulent reactive flows using a hybrid LES/PDF methodology." Chasseneuil-du-Poitou, Ecole nationale supérieure de mécanique et d'aérotechnique, 2011. http://www.theses.fr/2011ESMA0015.
Повний текст джерелаThe present work is devoted to the development and implementation of a computational framework to perform numerical simulations of low Mach number turbulent reactive flows. The numerical algorithm designed for solving the transport equations relies on a fully implicit predictor-corrector integration scheme. A physically consistent constraint is retained to ensure that the velocity field is solved correctly, and the numerical solver is extensively verified using the Method of Manufactured Solutions (MMS) in both incompressible and variable-density situations. The final computational model relies on a hybrid Large Eddy Simulation / transported Probability Density Function (LES-PDF) framework. Two different turbulence closures are implemented to represent the residual stresses: the classical and the dynamic Smagorinsky models. The specification of realistic turbulent inflow boundary conditions is also addressed in details, and three distinct methodologies are implemented. The crucial importance of this issue with respect to both inert and reactive high fidelity numerical simulations is unambiguously assessed. The influence of residual sub-grid scale scalar fluctuations on the filtered chemical reaction rate is taken into account within the Lagrangian PDF framework. The corresponding PDF model makes use of a Monte Carlo technique: Stochastic Differential Equations (SDE) equivalent to the Fokker-Planck equations are solved for the progress variable of chemical reactions. With the objective of performing LES of turbulent reactive flows in complex geometries, the use of distributed computing is mandatory, and the retained domain decomposition algorithm displays very satisfactory levels of speed-up and efficiency. Finally, the capabilities of the resulting computational model are illustrated on two distinct experimental test cases: the first is a two-dimensional highly turbulent premixed flame established between two streams of fresh reactants and hot burnt gases which is stabilized in a square cross section channel flow. The second is an unconfined high velocity turbulent jet of premixed reactants stabilized by a large co-flowing stream of burned products
Sbai, Youssef. "Analyse semi-classique des opérateurs périodiques perturbés." Thesis, Bordeaux, 2015. http://www.theses.fr/2015BORD0270/document.
Повний текст джерелаThis Ph.D thesis deals with some spectral properties of two specific classes of two periodic operators. We are firstly interested in the model periodic perturbed by operator depending on a small semi-classical constant. We obtain an asymptotic behavior of the eigenvalue counting function in the spectral gaps with scharp remainder estimate. The second model studied in this thesis is a two-dimensional periodic elliptic second order opera-tor perturbed by operator depending on a large coupling constant. We also give the description of the counting function of eigenvalues when the coupling constant tends to infinity. The last part of this thesis highlights the study the spectrum of a Schrödinger operator perturbed by a fast oscillatingdecaying potential depending on a small parameter
Ould, Maouloud Sidi Mohamed. "Quelques aspects fonctionnels et non fonctionnels des grandes déviations et des déviations modérées en estimation non-paramétrique." Phd thesis, Université de Reims - Champagne Ardenne, 2007. http://tel.archives-ouvertes.fr/tel-00266890.
Повний текст джерелаGermain, Cécile. "Étude des mécanismes de communication pour une machine massivement parallèle : mega." Paris 11, 1989. http://www.theses.fr/1989PA112385.
Повний текст джерелаThe Machine to Explore Giant Architectures (MEGA) project of the "Architecture et Conception des Circuits Intégrés" team of the LRI includes both the study of a logical model, the Dynamic Processes Networks, and of a hardware architecture, the MEGA machine. MEGA is a MIMD message-passing machine, intended to support an Ether communication model. Its target is very massive parallelism, up to 1 Million Elementary Processors. Each of these processors integrates in a single VLSI chip a processing unit, a local memory and a communication management unit. The communication design is one of the key features of such an architecture. It bears a very high technological constraint from a feasibility point of view, but it's performances determines the whole system ones. Therefore hardware parallelism may be actually useful only if the communication to computation ratio may be balanced. The communication design study includes three points of view : the communication model as an interface between software and hardware communication tools, the network topology and the routing strategy. In the three cases, the extreme parallelism target induced us to propose solutions which are original beside these in use in medium-grain multicomputers such as the commercial hypercubes. The communication model offers a direct interprocess relation when possible and allows however the processes graph dynamicity. The constant wiring density comparison for topologies shows that low dimensional meshes have better performances than hypercubes; the 3D mesh is then a good compromise between performances and feasibility constraints. We developed also a new routing strategy which we called Forced Routing. This strategy provides an efficient channels use. It limits contention by a randomized dispersion of messages and only needs very little buffering area. We achieved a logical specification for a routing and network/processor interface circuit. This circuit manages the messages without interfering with the processing unit activity and implements Forced Routing
Silva, Daniela Silva da. "Avaliação da densidade microvascular e graduação histológica em tumores mamários caninos." Universidade Federal de Pelotas, 2014. http://repositorio.ufpel.edu.br:8080/handle/prefix/3035.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES
O presente trabalho é constituído por estudos que visam avaliar potenciais marcadores prognósticos para tumores mamários caninos. Realizou-se um levantamento retrospectivo dos dados do Laboratório Regional de Diagnóstico da Faculdade de Veterinária da Universidade Federal de Pelotas (UFPel) acerca da casuística de dados clínico-patológicos de paciente com tumores mamários em diferentes períodos entre 2000-2012. A dissertação está apresentada na forma de dois artigos científicos. O primeiro artigo consiste da avalição do valor prognóstico do método de graduação de Elston e Ellis (1991). Foram avaliados 218 tumores. Verificou-se que a relação entre o tipo de tumor e tempo de sobrevida dos pacientes foi significativo (p<0,0001); que a maioria dos tumores pertenciam ao grau II (77/144-53.52%) e o grau tumoral influencia no tempo de sobrevida (p<0,0447). No segundo artigo estudou-se a possibilidade do uso da mensuração da densidade microvascular como fator prognóstico em tumores mamários caninos. Inicialmente dois métodos diferentes de mensuração de densidade vascular (campos aleatórios e hot-spot) foram avaliados e demonstrou-se que são equivalentes. Verificou-se que tanto a contagem de campos aleatórios ou contagem em áreas de intensa proliferação vascular apresentam resultados similares. Nos 218 neoplasmas avaliados não houve relação significativa entre o tipo histológico e o grau em relação a mensuração densidade microvascular, avaliadas pelos 2 métodos. Tumores de grau I apresentaram mais vasos que os de grau II e III. Conclui-se que no presente trabalho os carcinossarcomas foram os tumores mais prevalentes na casuística avaliada; que a associação do tipo e grau histológico tem valor prognóstico, enquanto que densidade microvascular não é um bom fator prognóstico para tumores mamários caninos.
This manuscript aims evaluate potential morphological prognostic factors to canine mammary tumors. Retrospective chart reviews of data from the Regional Diagnostic Laboratory were carried out to obtain the clinical and pathological features of the patients and mammary tumors in different periods from 2000 to 2012. The dissertation will be presented as two scientific manuscripts. The first manuscript aims the evaluation of the prognostic graduation method of Elston e Ellis (1991). A total of 218 tumors were evaluated. The relationship between tumor type and survival time were significant (p<0.0001). It was observed a preponderance of grade II (77/144-53.52%) tumors and also that the tumor grade can influence survival time (p<0.0447). The second manuscript evaluates the microvascular density as a prognostic factor in canine mammary tumors. Initially, two methods of mensuration (aleatory fields and hot spot) were evaluated and proved to be equivalent. In the 218 tumors evaluated no significant results were obtained in the comparison of histologic type or tumor grade with microvascular density evaluated by both methods. Grade I tumors presented more vessels than grade II or III tumors. It was possible to conclude that carcinosarcomas are the prevalent tumor type; association between tumor type and histologic grade could be used as prognostic factor. Microvascular density not consists in a good prognostic factor.
Macario, Mélanie. "L'aménagement des centres-villes : la mobilité, vecteur et acteur de la centralité urbaine." Thesis, Aix-Marseille, 2012. http://www.theses.fr/2012AIXM1003/document.
Повний текст джерелаIn this study, core-city planning is compared with the major political, economic, social and religious mutations that have marked the evolution of our society and have gradually transformed the structure and uses of the city. While it was previously organized around a single powerful, unifying and symbolic centre, today as a result of metropolisation the city is structured around several poles of centrality each in accordance with a specific logic and purpose. Faced with these structural changes, the core-city is subject to new forms of appropriation, which challenge its role in the urban system. As the driving force of the city, the core-city does not exist in isolation: on the contrary, it is in constant interaction with its surroundings and so must be apprehended in its globality. Urban planning and development requires understanding the link between this core, which reflects a certain stability due to high urban density, and the rest of the city, characterized on the contrary by generalized mobility. Based on a retrospective analysis, this systemic approach goes counter to the sectoral vision of urban planning laws and is intended to demonstrate the relationship between the failure of both the core-city planning policies and the planning policies of the periphery. At the same time, a government-advocated return to the "compact city" in order to limit urban sprawl and automobile traffic raises a recurring problem in core-city planning: how to reconcile their density with their accessibility
Lecocq, Guillaume. "Approches hybrides combinant chimie complexe, description statistique et densité de surface de flamme pour la simulation aux grandes échelles de l'auto-inflammation, l'allumage par bougie et la flamme de prémélange dans les moteurs à allumage commandé." Phd thesis, INSA de Rouen, 2010. http://tel.archives-ouvertes.fr/tel-00561996.
Повний текст джерелаHansen, Per. "Potentiell koppling mellan elektrolys och landbaseradfiskodling : En analys av behov och tillgång på syrgas och värme." Thesis, Högskolan i Gävle, Miljövetenskap, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-36512.
Повний текст джерелаThere will be a major expansion of electrolysis for production of hydrogen in Sweden and the rest of the world. To reduce production costs and thus make hydrogencheaper, this report analyzes how much oxygen and heat a fish farm consumes andtherefore would need to buy from an electrolyser. The analysis shows that the species used in the study - tilapia (Oreochromis, Oreochromis, Alcolapia), rainbow(Oncorhynchus mykiss) and salmon (Salmo salar) - in a farm that produces 40 tonsof fish per year would consume 1.16 percent of the oxygen and 0,35 percent of theheat produced from a 3 MW PEM electrolyzer. The value of the oxygen and theheat from a 3 MW electrolyser is calculated at SEK 694,939/year for the oxygenand SEK 1,829,813/year for the heat. The average cost for the species in the studyin a 40 tonne/year fish farm is calculated at SEK 8,900/year for the oxygen and SEK6,400/year for the heat in a land-based fish farm.
Telles, Felipe Bottona da Silva. "Os anfíbios da restinga de Grumari, RJ, Brasil, e a comunidade de folhiço em duas zonas arbóreas." Universidade do Estado do Rio de Janeiro, 2011. http://www.bdtd.uerj.br/tde_busca/arquivo.php?codArquivo=4020.
Повний текст джерелаAlthough restinga habitats represent approximately 5000 km of the Brazilian coast, the information available about the composition of the anuran fauna present on those habitats are restricted to relatively few areas. Nowadays restinga habitats are under intense set of pressures as result of a demographic density five times higher than the average for the country leading to the occupation, degradation and eventual loss of such habitats. This is especially alarming for the threatened endemic populations of terrestrial vertebrates due to the difficulty of vegetation recovery after clearings. Presently, the remnants of these habitats along much of the eastern Brazilian coast are represented by completely isolated fragments. Herein we present the first approximation to the list of the amphibians from the restinga of Grumari, inserted in the Parque Natural Municipal de Grumari (PNMG), municipality of Rio de Janeiro, Rio de Janeiro state, southeastern Brazil. The area is situated in the Atlantic Rainforest Biome. Its also the first study on the community of litter anuran fauna, obtaining density data, for the Brazilian restinga. The study was carried out from May 2009 to December 2010 using two sampling methods: quadrant plots (4x4 m) and acoustic/visual transects. We recorded 22 species of anuran amphibians distributed in six families: Leptodactylidae (3), Craugastoridae (1), Bufonidae (1), Strabomantidae (1), Microhylidae (2) and Hylidae (14). We found ten species of litter frogs in 2560 m of sampled forest floor with the methodology of large plots. In the closed post-beach zone, there were only seven species of anuran leaf litter, while the restinga forest zone present the ten species recorded for the restinga. The overall density of litter frogs at the restinga of Grumari was 13.1 individuals per 100m, more than five of six published studies on the density of litter frogs in the Atlantic Rainforest. The estimated total biomass was 13131 g/100m, being currently the area with highest litter frog biomass on the planet. There was no statistically significant difference between the zones regarding community parameters (richness, density and biomass), even though there is difference between the environmental parameters measured in both zones. The factors that best explained the richness, density and biomass in the restinga of Grumari during the rainy season were, respectively, temperature, diameter of the trees/shrubs and the number of trees/shrubs. The presence of endangered and endemic species indicates that the restinga of Grumari is an important area for conservation of the anuran fauna in remnants of these habitats in the Rio de Janeiro state, being currently the richest known area in terms of amphibian species of all restinga areas in the state, and the second richest of the Brazilian restingas studied up to now.
Kodym, Oldřich. "Analýza 3D CT obrazových dat se zaměřením na stanovení hustoty kostních elementů." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2017. http://www.nusl.cz/ntk/nusl-316824.
Повний текст джерелаThiam, Baba. "Estimation récursive de fonctionnelles." Phd thesis, Université de Versailles-Saint Quentin en Yvelines, 2006. http://tel.archives-ouvertes.fr/tel-00131199.
Повний текст джерелаAhmed, Aqeel. "LES of atomization and cavitation for fuel injectors." Thesis, Normandie, 2019. http://www.theses.fr/2019NORMR048/document.
Повний текст джерелаThis thesis presents Large Eddy Simulation (LES) of fuel injection, atomization and cavitation inside the fuel injector for applications related to internal combustion engines. For atomization modeling, Eulerian Lagrangian Spray Atomization (ELSA) model is used. The model solves for volume fraction of liquid fuel as well as liquid-gas interface surface density to describe the complete atomization process. In this thesis, flow inside the injector is also considered for subsequent study of atomization. The study presents the application of ELSA model to a typical diesel injector, both in the context of RANS and LES. The model is validated with the help of experimental data available from Engine Combustion Network (ECN). The ELSA model which is normally designed for diffused (unresolved) interfaces, where the exact location of the liquid-gas interface is not considered, is extended to work with Volume of Fluid (VOF) type formulation of two phase flow, where interface is explicitly resolved. The coupling is achieved with the help of Interface Resolution Quality (IRQ) criteria, that takes into account both the interface curvature and modeled amount of interface surface. ELSA model is developed first considering both phases as incompressible, the extension to compressible phase is also briefly studied in this thesis, resulting in compressible ELSA formulation that takes into account varying density in each phase. In collaboration with Imperial College London, the Probability Density Function (PDF) formulation with Stochastic Fields is also explored to study atomization. In modern fuel injection systems, quite oftenthe local pressure inside the injector falls below the vapor saturation pressure of the fuel, resulting in cavitation. Cavitation effects the external flow and spray formulation. Thus, a procedure is required to study the phase change as well as jet formulation using a single and consistent numerical setup. A method is developed in this thesis that couples the phase change inside the injector to the external jet atomization. This is achieved using the volume of fluid formulation where the interface is considered between liquid and gas; gas consists of both the vapor and non condensible ambient air
Seltz, Andréa. "Application of deep learning to turbulent combustion modeling of real jet fuel for the numerical prediction of particulate emissions Direct mapping from LES resolved scales to filtered-flame generated manifolds using convolutional neural networks Solving the population balance equation for non-inertial particles dynamics using probability density function and neural networks: application to a sooting flame." Thesis, Normandie, 2020. http://www.theses.fr/2020NORMIR08.
Повний текст джерелаWith the climate change emergency, pollutant and fuel consumption reductions are now a priority for aircraft industries. In combustion chambers, the chemistry and soot modeling are critical to correctly quantify engines soot particles and greenhouse gases emissions. This thesis aimed at improving aircraft numerical pollutant tools, in terms of computational cost and prediction level, for engines high fidelity simulations. It was achieved by enhancing chemistry reduction tools, allowing to predict CO emissions of an aircraft engines at affordable cost for the industry. Next, a novel closure model for unresolved terms in the LES filtered transport equations is developed, based on neural networks (NN), to propose a better flame modeling. Then, an original soot model for engine high fidelity simulations is presented, also based on NN. This new model is applied to a one-dimensional premixed sooted flame, and finally to an industrial combustion chamber LES with measured soot comparison
Ferreira, Vitor Maciel Vilela. "A hybrid les / lagrangian fdf method on adaptive, block-structured mesh." Universidade Federal de Uberlândia, 2015. https://repositorio.ufu.br/handle/123456789/14982.
Повний текст джерелаEsta dissertação é parte de um amplo projeto de pesquisa, que visa ao desenvolvimento de uma plataforma computacional de dinâmica dos fluidos (CFD) capaz de simular a física de escoamentos que envolvem mistura de várias espécies químicas, com reação e combustão, utilizando um método hibrido Simulação de Grandes Escalas (LES) / Função Densidade Filtrada (FDF) Lagrangiana em malha adaptativa, bloco-estruturada. Uma vez que escoamentos com mistura proporcionam fenômenos que podem ser correlacionados com a combustão em escoamentos turbulentos, uma visão global da fenomenologia de mistura foi apresentada e escoamentos fechados, laminar e turbulento, que envolvem mistura de duas espécies químicas inicialmente segregadas foram simulados utilizando o código de desenvolvimento interno AMR3D e o código recentemente desenvolvido FDF Lagrangiana de composição. A primeira etapa deste trabalho consistiu na criação de um modelo computacional de partículas estocásticas em ambiente de processamento distribuído. Isto foi alcançado com a construção de um mapa Lagrangiano paralelo, que pode gerenciar diferentes tipos de elementos lagrangianos, incluindo partículas estocásticas, particulados, sensores e nós computacionais intrínsecos dos métodos Fronteira Imersa e Acompanhamento de Interface. O mapa conecta informações Lagrangianas com a plataforma Euleriana do código AMR3D, no qual equações de trans- porte são resolvidas. O método FDF Lagrangiana de composição realiza cálculos algébricos sobre partículas estocásticas e provê campos de composição estatisticamente equivalentes aos obtidos quando se utiliza o método de Diferenças Finitas para solução de equações diferenciais parciais; a técnica de Monte Carlo foi utilizada para resolver um sistema derivado de equações diferenciais estocásticas (SDE). Os resultados concordaram com os benchmarks, que são simulações baseadas em plataforma de Diferenças Finitas para solução de uma equação de transporte de composição filtrada.
This master thesis is part of a wide research project, which aims at developing a com- putational fluid dynamics (CFD) framework able to simulate the physics of multiple-species mixing flows, with chemical reaction and combustion, using a hybrid Large Eddy Simulation (LES) / Lagrangian Filtered Density Function (FDF) method on adaptive, block-structured mesh. Since mixing flows provide phenomena that may be correlated with combustion in turbulent flows, we expose an overview of mixing phenomenology and simulated enclosed, ini- tially segregated two-species mixing flows, at laminar and turbulent states, using the in-house built AMR3D and the developed Lagrangian composition FDF codes. The first step towards this objective consisted of building a computational model of notional particles transport on distributed processing environment. We achieved it constructing a parallel Lagrangian map, which can hold different types of Lagrangian elements, including notional particles, particu- lates, sensors and computational nodes intrinsic to Immersed Boundary and Front Tracking methods. The map connects Lagrangian information with the Eulerian framework of the AMR3D code, in which transport equations are solved. The Lagrangian composition FDF method performs algebraic calculations over an ensemble of notional particles and provides composition fields statistically equivalent to those obtained by Finite Differences numerical solution of partially differential equations (PDE); we applied the Monte Carlo technique to solve a derived system of stochastic differential equations (SDE). The results agreed with the benchmarks, which are simulations based on Finite Differences framework to solve a filtered composition transport equation.
Mestre em Engenharia Mecânica
Siemes, Kerstin. "Establishing a sea bottom model by applying a multi-sensor acoustic remote sensing approach." Doctoral thesis, Universite Libre de Bruxelles, 2013. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/209381.
Повний текст джерелаChapters 4 and 5 are adapted from published work, with permission:
DOI:10.1121/1.3569718 (link: http://asadl.org/jasa/resource/1/jasman/v129/i5/p2878_s1) and
DOI:10.1109/JOE.2010.2066711 (link: http://ieeexplore.ieee.org/xpl/articleDetails.jsp?tp=&arnumber=5618582&queryText%3Dsiemes)
In reference to IEEE copyrighted material which is used with permission in this thesis, the IEEE does not endorse any of the Université libre de Bruxelles' products or services.
Doctorat en Sciences de l'ingénieur
info:eu-repo/semantics/nonPublished
Duro, Vincent. "Caractérisation acoustique d'un sillage engendré par un navire de surface : propagation d'une onde acoustique dans un mélange eau/bulles d'air." Le Havre, 2009. http://www.theses.fr/2009LEHA0019.
Повний текст джерелаThis work is devoted to the acoustical characterization of ship wake. In a laboratory, wake reduces to bubbly water medium. The influence of bubbles on the propagation of a transmitted acoustical wave is studied. Sound attenuation and phase speed measurements permit to determine the bubble radius and the bubble density. Thanks to the theoretical studies of acoustical scattering by a single air bubble in water, a relationship between bubble radius and their resonance at low frequency is established. Next, from the Foldy relationship giving an effective wavenumber characterizing the acoustical propagation in bubbly water, attenuation change and phase speed change are observed around bubble resonance frequency. The values of these changes increase with the bubble density increasing. Additionally, an optical measurement method investigated simultaneously provides results in good agreement with the ones due to the method of acoustical measurements. This work achieves by the presentation of results obtained during prospective experiments. In fact, this section shows the results of non-linear acoustical propagation and gap-band effects in relation with bubbly water
Huang, Chiu-Fang, and 黃久芳. "Extended Jacobson Density Theorem for Graded Module." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/85067985547688591017.
Повний текст джерела國立成功大學
數學系應用數學碩博士班
92
We study the extended Jacobson Density Theorem for graded rings with graded local modules, and introduce the concept of a derivation d:A --> End(M_{D}) for graded rings,where M is a graded simle left A-module and D=End(_{A}M).
梁景揮. "Extended Jacobson Density Theorem and M-outer Automorphisms for Graded Rings." Thesis, 2000. http://ndltd.ncl.edu.tw/handle/97248284624906928715.
Повний текст джерелаXia, Ye. "Cladding Protection of Reinforced Concrete Structural Members against Blast Loading." Thesis, 2017. http://hdl.handle.net/2440/119190.
Повний текст джерелаThesis (Ph.D.) -- University of Adelaide, School of Civil, Environmental and Mining Engineering, 2017
Jing-YuanLiao and 廖經元. "Analysis of a Functionally Graded Plane with a Central Crack by Using Strain Energy Density Theory." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/47387209212798015596.
Повний текст джерелаCHANG, YA-WEN, and 張雅雯. "Density Data Modeling Capibilities -- Degree of Understanding of Different Density Concept of 8 Graders." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/a32chn.
Повний текст джерела國立高雄師範大學
科學教育暨環境教育研究所
107
Abstract In an aim to compare and analyze the learning outcomes of students in 8th grade when they implement data modeling techniques to solve dense problems, the study looks at how students with different academic levels design and complete virtual experiments in computer programs to learn the concepts of density. The research conducts surveys with 138 students, who have already learned density in class. First, they receive a test on density. Next, they work on virtual experiments and apply data modeling techniques. Finally, they receive another test on data modeling. To sum, the students have to work on projects in virtual environments and learn various computer-based data models. Test Tools Two test tools are used in the study. The first test tool applied in the research process is the Density Concept Understanding Test, designed by Gu Binghong, Chen Qiongsen and Wen Yuchun, which results in KR-20 reliability statistics of 0.79 and internal consistency as 0.87; and, the research process has adapted 9 out of 10 concepts as well as 25 questions from the test. Apart from the first test tool, the second test tool applied in the research focuses on particular methods proposed by Ärlebäck, Blomberg and Nilsson (2014), including 8 concepts and 24 questions and resulting in KR-20 reliability statistics of 0.88. Nevertheless, datas from statistical analysis including descriptive statistics, one-way anova and multiple posteriori comparison are collected to compare and analyze the learning outcomes for 3 groups of students while they implement data modeling techniques to solve dense problems. Results (1) There is great difference in data modeling performance between students with high, medium and low levels of understanding density: (p < .05) Students with advanced level of understanding perform better than those with medium level of understanding, and those with medium level of understanding perform better than those with low level of understanding. (2) Students with high level of understanding are able to “systematically collect, organize and describe data,” “construct, read, and interpret tables, charts, and graphs,” “describe, extend, analyze and create a wide variety of patterns,” “describe and represent relationships with tables, graphs, and rules,” and apply data model, showing a dominant performance (correct rate > 75%); however, the group’s ability to “analyze functional relationships to explain how a change in one quantity results in a change in another” shows a weak performance (correct rate < 65%). (3) Students with medium level of understanding show weak performance in every aspect of data modeling process, except that the group’s ability to “systematically collect, organize and describe data” has achieved dominance. (4) Students with low level of understanding show weak performance in every aspect of data modeling process.
Li, Zong Ru, and 李宗儒. "Design and Grade Transition of an Industrial High-Density Polyethylene Process." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/f5m9kk.
Повний текст джерелаWang, Te-Ling, and 王德麟. "The Influence of Inquiry-Oriented Teaching to Grade Eight Students’ Learning Outcome on the Unit of Density." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/89158176481103399404.
Повний текст джерела國立高雄師範大學
科學教育研究所
94
The aims of this research were to explore the effects of inquiry-oriented teaching on density unit on students’ scientific concept, nature of scientific inquiry, the scientific inquiry abilities, and the perceptions of the classroom learning environments. The researcher hoped to understand the difficulties of this kind of teaching practice from this research. One class of 8th graders participated in six-weeks inquiry-oriented teaching. The researcher used questionnaires on density concepts, inquiry abilities, nature of scientific inquiry and WIHIC as research tools to carry out the pre- and post-test individually. Interviews were also administered to the students in order to collect deeper understanding of the changing factors from the students. The researcher analyzed the quantitative data with the statistical software and collected the correlated information in order to explain the result of the qualitative data and to organize the research results. The findings of the study indicated that inquiry-oriented teaching is helpful for students’ concept understanding on density, but some students still held on some alternative conceptions. Students’ inquiry abilities on “Observation and Recording” & “Designing Experiment” increased and were statistic significant. In the nature of scientific inquiry, quantitative data showed that students’ understanding changed but the change is not significant. In the WIHIC, the quantitative and qualitative data on students’ perceptions just had some advance in all aspects. According to the students’ answers on suitability of learning, it indicated that students thought that inquiry-oriented teaching was appropriate. Obstacles in inquiry teaching were the limit of time and instruments, students’ learning and adaptability, belief and the teacher’s emotion and immobile pressure from examinations.