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University of Technology, Sydney
1.
Gong, Mingming.
Causal and causally-inspired learning.
Degree: 2017, University of Technology, Sydney
URL: http://hdl.handle.net/10453/116802
► A main goal of statistics and machine learning is to discover statistical dependencies between random variables, and these dependencies will be used to perform predictions…
(more)
▼ A main goal of statistics and machine learning is to discover statistical dependencies between random variables, and these dependencies will be used to perform predictions on future observations. However, many scientific investigations involve causal predictions, the aim of which is to infer how the data generating system should behave under changing conditions, for example, changes induced by external interventions. To perform causal predictions, we need both statistical dependencies as well as causal structures to determine the behaviour of the system. The standard way to identify causal structures is to use randomized controlled experiments. However, conducting these experiments is usually expensive or even impossible in many scenarios. As a consequence, inferring cause and effect relationships from purely observational data, known as causal discovery or causal learning, has drawn much attention.
Various causal discovery methods have been proposed in the past decades, including constraint-based methods, structural equation models-based methods, and time series-based methods. Among these methods, time series-based methods, e.g., Granger causality, are relatively well-established as the temporal information excludes the case that effects happen before causes. Many of the existing time series-based methods assume that the data are measured at the right frequency; however, in practice the sampling frequency of the data is often lower than the true causal frequency. In this thesis, we consider learning high-resolution causal relationships at the causal frequency from subsampled time series. Existing methods suffer from the identifiability problems: under the Gaussianity assumption of the data, the solutions are generally not unique. We prove that, however, if the noise terms are non-Gaussian, the underlying model is identifiable from subsampled time series under mild conditions. We then propose an Expectation-Maximization approach and a variational inference approach to recover causal relations from subsampled data.
More recently, researchers began to touch upon implications of causal models for machine learning tasks such as semi-supervised learning and domain adaptation. In this thesis, we develop causally-inspired learning methods for domain adaptation in both multi-source and single-source settings. In particular, we use causal models to represent the relationship between the features and labels, and consider possible situations where different modules of the causal model change with the domain. In each situation, we investigate what knowledge is appropriate to transfer and find the optimal target-domain hypothesis. Furthermore, we propose methods to correct distribution shift in the general situation where the marginal distribution of features and conditional distribution of labels given features both change, under the assumption that labels are causes for features. We provide theoretical analysis and empirical evaluation on both synthetic and real-world data to show the effectiveness of our methods.
Subjects/Keywords: Causal predictions.; Statistical dependencies.; Granger causality.; Expectation-Maximization approach.; Variational inference approach.
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APA (6th Edition):
Gong, M. (2017). Causal and causally-inspired learning. (Thesis). University of Technology, Sydney. Retrieved from http://hdl.handle.net/10453/116802
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Gong, Mingming. “Causal and causally-inspired learning.” 2017. Thesis, University of Technology, Sydney. Accessed March 07, 2021.
http://hdl.handle.net/10453/116802.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Gong, Mingming. “Causal and causally-inspired learning.” 2017. Web. 07 Mar 2021.
Vancouver:
Gong M. Causal and causally-inspired learning. [Internet] [Thesis]. University of Technology, Sydney; 2017. [cited 2021 Mar 07].
Available from: http://hdl.handle.net/10453/116802.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Gong M. Causal and causally-inspired learning. [Thesis]. University of Technology, Sydney; 2017. Available from: http://hdl.handle.net/10453/116802
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of Melbourne
2.
KIRSZENBLAT, DAVID.
The Steiner ratio conjecture for eight points.
Degree: 2014, University of Melbourne
URL: http://hdl.handle.net/11343/44115
► Given a set X of n points in the euclidean plane R2, a Steiner minimal tree is a shortest network interconnecting X. Note that a…
(more)
▼ Given a set X of n points in the euclidean plane R2, a Steiner minimal tree is a shortest network interconnecting X. Note that a Steiner minimal tree may contain extra vertices, referred to as Steiner points, not already in X. The problem of finding a Steiner minimal tree is NP-hard. A Steiner minimal tree can, however, be approximated by a minimum spanning tree, which can be found in polynomial time in n. A measure for the performance of a Steiner minimal tree compared with that of a minimum spanning tree is given by the Steiner ratio ρ, the ratio of lengths between a Steiner minimal tree and a minimum spanning tree.
In 1968, Gilbert and Pollak conjectured that ρ ≥ √3/2 for any X. The conjecture was subsequently verified for several small values of n. For example, Rubinstein and Thomas applied some ideas from the calculus of variations to verify the conjecture for n = 6. Then, in 1992, Du and Hwang published a paper concerning the general problem, with convexity and flexibility as the major ideas. It has since been pointed out, however, that the argument of Du and Hwang contains a gap. Nevertheless, their argument contains many elegant ideas which may still be retained.
In this thesis, we use a combination of techniques drawn from both the work of Rubinstein and Thomas as well as that of Du and Hwang to verify the conjecture for n = 8. Whereas Du and Hwang chose to work with a restricted set of spanning trees, we opt to work with the full set of spanning trees. We introduce the notion of symmetry breaking into the conception of the problem in order to fully exploit the idea of flexibility. We also adapt some material from rigidity theory, the study of bar-and-joint frameworks, in order to ensure that our arguments apply to both generic and nongeneric situations.
Subjects/Keywords: Steiner tree; spanning tree; Steiner ratio; variational approach; convexity; rigidity.
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APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
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APA (6th Edition):
KIRSZENBLAT, D. (2014). The Steiner ratio conjecture for eight points. (Masters Thesis). University of Melbourne. Retrieved from http://hdl.handle.net/11343/44115
Chicago Manual of Style (16th Edition):
KIRSZENBLAT, DAVID. “The Steiner ratio conjecture for eight points.” 2014. Masters Thesis, University of Melbourne. Accessed March 07, 2021.
http://hdl.handle.net/11343/44115.
MLA Handbook (7th Edition):
KIRSZENBLAT, DAVID. “The Steiner ratio conjecture for eight points.” 2014. Web. 07 Mar 2021.
Vancouver:
KIRSZENBLAT D. The Steiner ratio conjecture for eight points. [Internet] [Masters thesis]. University of Melbourne; 2014. [cited 2021 Mar 07].
Available from: http://hdl.handle.net/11343/44115.
Council of Science Editors:
KIRSZENBLAT D. The Steiner ratio conjecture for eight points. [Masters Thesis]. University of Melbourne; 2014. Available from: http://hdl.handle.net/11343/44115

Louisiana State University
3.
Mozaffari, Navid.
Damage Evolution in Pressurized Domain: A Gradient Based Variational Approach.
Degree: MS, Applied Mathematics, 2014, Louisiana State University
URL: etd-11172014-003502
;
https://digitalcommons.lsu.edu/gradschool_theses/442
► Construction of appropriate models through mathematical analysis for materials in order to find their main properties and ingredients and enhance the numerical simulations to predict…
(more)
▼ Construction of appropriate models through mathematical analysis for materials in order to find their main properties and ingredients and enhance the numerical simulations to predict their behavior under specific conditions is in interest even in mathematics departments rather than material science and engineering branches. Among these models, gradient damage models have reached to the specific stage because of their ability to bring the effects of micro cracks propagation into conventional continuum mechanics formulation and approximate brittle fracture as one of the most phenomena in the area of material behavior simulation. This thesis includes the application and extension of a previously proposed gradient damage model through the mathematical analysis on a specific 2D problem i.e. axisymmetric domain with internal pressure, which is in interest for designing reservoirs and investigating crack propagation around oil wells. To accomplish this task, this thesis is organized as following. In the first chapter, general framework and fundamentals of damage models is discussed in details including standard models and incorporation of gradient term into standard models through variational approach. Main properties of gradient damage models are derived and all details of derivations including proofs of some propositions are added to show the flow of the presentation. In the second chapter, presented formulation is applied on a desired problem in details to show the application of the model in 2D. Discussion on main results and some recommendations are given in the last chapter.
Subjects/Keywords: Pressurized domain; Gradient damage; Damage evolution; Variational approach
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Mozaffari, N. (2014). Damage Evolution in Pressurized Domain: A Gradient Based Variational Approach. (Masters Thesis). Louisiana State University. Retrieved from etd-11172014-003502 ; https://digitalcommons.lsu.edu/gradschool_theses/442
Chicago Manual of Style (16th Edition):
Mozaffari, Navid. “Damage Evolution in Pressurized Domain: A Gradient Based Variational Approach.” 2014. Masters Thesis, Louisiana State University. Accessed March 07, 2021.
etd-11172014-003502 ; https://digitalcommons.lsu.edu/gradschool_theses/442.
MLA Handbook (7th Edition):
Mozaffari, Navid. “Damage Evolution in Pressurized Domain: A Gradient Based Variational Approach.” 2014. Web. 07 Mar 2021.
Vancouver:
Mozaffari N. Damage Evolution in Pressurized Domain: A Gradient Based Variational Approach. [Internet] [Masters thesis]. Louisiana State University; 2014. [cited 2021 Mar 07].
Available from: etd-11172014-003502 ; https://digitalcommons.lsu.edu/gradschool_theses/442.
Council of Science Editors:
Mozaffari N. Damage Evolution in Pressurized Domain: A Gradient Based Variational Approach. [Masters Thesis]. Louisiana State University; 2014. Available from: etd-11172014-003502 ; https://digitalcommons.lsu.edu/gradschool_theses/442

Louisiana State University
4.
Mesgarnejad, Ataollah.
Development of a Work-controlled Algorithm for the Variational Approach to Fracture Mechanics and Its Application to Sandstone Burst Experiments.
Degree: MS, Applied Mathematics, 2014, Louisiana State University
URL: etd-11162014-140834
;
https://digitalcommons.lsu.edu/gradschool_theses/3007
► In this thesis we use the variational approach to fracture mechanics to study the burst experiments on sandstone. We develop a new work controlled algorithm…
(more)
▼ In this thesis we use the variational approach to fracture mechanics to study the burst experiments on sandstone. We develop a new work controlled algorithm that helps to remedy sudden crack propagation and adds to the accuracy of the predicted loads. We show that the numerical simulations based on the variational approach to fracture mechanics accurately predict the burst pressures for the zero outer pressure tests. We identify the main contributing issues that result in deviation of the numerical results from the experimental observations and suggest some modifications to limit these problems.
Subjects/Keywords: burst experiments; brittle fracture; Variational approach to fracture mechanics
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Mesgarnejad, A. (2014). Development of a Work-controlled Algorithm for the Variational Approach to Fracture Mechanics and Its Application to Sandstone Burst Experiments. (Masters Thesis). Louisiana State University. Retrieved from etd-11162014-140834 ; https://digitalcommons.lsu.edu/gradschool_theses/3007
Chicago Manual of Style (16th Edition):
Mesgarnejad, Ataollah. “Development of a Work-controlled Algorithm for the Variational Approach to Fracture Mechanics and Its Application to Sandstone Burst Experiments.” 2014. Masters Thesis, Louisiana State University. Accessed March 07, 2021.
etd-11162014-140834 ; https://digitalcommons.lsu.edu/gradschool_theses/3007.
MLA Handbook (7th Edition):
Mesgarnejad, Ataollah. “Development of a Work-controlled Algorithm for the Variational Approach to Fracture Mechanics and Its Application to Sandstone Burst Experiments.” 2014. Web. 07 Mar 2021.
Vancouver:
Mesgarnejad A. Development of a Work-controlled Algorithm for the Variational Approach to Fracture Mechanics and Its Application to Sandstone Burst Experiments. [Internet] [Masters thesis]. Louisiana State University; 2014. [cited 2021 Mar 07].
Available from: etd-11162014-140834 ; https://digitalcommons.lsu.edu/gradschool_theses/3007.
Council of Science Editors:
Mesgarnejad A. Development of a Work-controlled Algorithm for the Variational Approach to Fracture Mechanics and Its Application to Sandstone Burst Experiments. [Masters Thesis]. Louisiana State University; 2014. Available from: etd-11162014-140834 ; https://digitalcommons.lsu.edu/gradschool_theses/3007

University of Adelaide
5.
Owen, Benjamin James.
A variational approach to hadron structure in lattice QCD.
Degree: 2015, University of Adelaide
URL: http://hdl.handle.net/2440/98247
► In order to understand how hadrons acquire their physical properties from their constituents, we must resort to the underlying theory of the strong interaction, Quantum…
(more)
▼ In order to understand how hadrons acquire their physical properties from their constituents, we must resort to the underlying theory of the strong interaction, Quantum Chromodynamics (QCD). However, the non-perturbative nature of this theory in the relevant energy scales renders the standard perturbative methods ineffective. The formulation of QCD on a discrete space-time lattice allows for a first principles, non-perturbative
approach to studying the strong interaction, in a manner well suited to numerical computation. Over the past decade, the use of
variational techniques has provided an effective framework for spectroscopic studies of the full hadron spectrum. Herein we generalise the use of the
variational approach to hadron form factor calculations and examine its use in a number of different hadronic systems. As such an
approach allows for the isolation of terms relevant to a single eigenstate or eigenstate transition, we show that this method is both an effective way to remove excited state contamination from the study of ground state systems and an effective framework through which one can study the structure of hadronic excitations. We begin with an evaluation of the nucleon axial charge, gᴀ, to investigate the improvement offered through this method and consider the role that excited states play in the discrepancy observed between lattice determinations and experiment. This is followed by a determination of the ρ-meson electromagnetic form factors Gс, Gм and GQ [Q subscript], and the corresponding radiative transition form factor Gм₁ using near physical masses. We then turn our attention to the electromagnetic form factors of the two lowest-lying negative parity nucleons, where such techniques are required to disentangle the contributions of these two near degenerate states. Here we present the first evaluation of the elastic form factors Gᴇ and Gм for both these low-lying states. Finally, through careful consideration of the Nγ → N* vertex, we develop an innovative formalism that allows one to evaluate radiative transition form factors for all spin-1/2 nucleon excitations. This novel formalism is implemented to provide the world’s first examination of the odd-parity transitions of the nucleon in lattice QCD.
Advisors/Committee Members: Leinweber, Derek Bruce (advisor), Kamleh, Waseem Rolf (advisor), School of Physical Sciences (school).
Subjects/Keywords: Hadron structure; excited states; electrotromagnetic form factors; transition form factors; correlation matrix; variational approach
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Owen, B. J. (2015). A variational approach to hadron structure in lattice QCD. (Thesis). University of Adelaide. Retrieved from http://hdl.handle.net/2440/98247
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Owen, Benjamin James. “A variational approach to hadron structure in lattice QCD.” 2015. Thesis, University of Adelaide. Accessed March 07, 2021.
http://hdl.handle.net/2440/98247.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Owen, Benjamin James. “A variational approach to hadron structure in lattice QCD.” 2015. Web. 07 Mar 2021.
Vancouver:
Owen BJ. A variational approach to hadron structure in lattice QCD. [Internet] [Thesis]. University of Adelaide; 2015. [cited 2021 Mar 07].
Available from: http://hdl.handle.net/2440/98247.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Owen BJ. A variational approach to hadron structure in lattice QCD. [Thesis]. University of Adelaide; 2015. Available from: http://hdl.handle.net/2440/98247
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
6.
Tran, Vinh Phuc.
Modélisation à plusieurs échelles d'un milieu continu hétérogène aléatoire : Stochastic modeling of random heterogeneous materials.
Degree: Docteur es, Mécanique, 2016, Université Paris-Est
URL: http://www.theses.fr/2016PESC1159
► Lorsque les longueurs caractéristiques sont bien séparées, la théorie de l'homogénéisation propose un cadre théorique rigoureux pour les matériaux hétérogènes. Dans ce contexte, les propriétés…
(more)
▼ Lorsque les longueurs caractéristiques sont bien séparées, la théorie de l'homogénéisation propose un cadre théorique rigoureux pour les matériaux hétérogènes. Dans ce contexte, les propriétés macroscopiques peuvent être calculées à partir de la résolution d’un problème auxiliaire formulé sur un volume élémentaire représentatif (avec des conditions limites adéquates). Dans le présent travail, nous nous intéressons à l’homogénéisation de matériaux hétérogènes décrits à l’échelle la plus fine par deux modèles différents (tous deux dépendant d’une longueur caractéristique spécifique) alors que le milieu homogène équivalent se comporte, dans les deux cas, comme un milieu de Cauchy classique.Dans la première partie, une microstructure aléatoire de type Cauchy est considérée. La résolution numérique du problème auxiliaire, réalisée sur plusieurs réalisations, implique un coût de calcul important lorsque les longueurs caractéristiques des constituants ne sont pas bien séparées et/ou lorsque le contraste mécanique est élevé. Pour surmonter ces limitations, nous basons notre étude sur une description mésoscopique du matériau combinée à la théorie de l'information. Dans cette mésostructure, obtenue par filtrage, les détails les plus fins sont lissés.Dans la seconde partie, nous nous intéressons aux matériaux à gradient dans lesquels il existe au moins une longueur interne, qui induit des effets de taille à l’échelle macroscopique. La microstructure aléatoire est décrite par un modèle à gradient de contrainte récemment proposé. Malgré leur similarité conceptuelle, nous montrerons que le modèle de stress-gradient et strain-gradient définissent deux classes de matériaux distinctes. Nous proposons ensuite des approches simples (méthodes de champs moyens) pour mieux comprendre les hypothèses de modélisation. Les résultats semi-analytiques obtenus nous permettent d’explorer l'influence des paramètres du modèle sur les propriétés macroscopiques et constituent la première étape vers la simulation en champs complets
If the length-scales are well separated, homogenization theory can provide a robust theoretical framework for heterogeneous materials. In this context, the macroscopic properties can be retrieved from the solution to an auxiliary problem, formulated over the representative volume element (with appropriate boundary conditions). In the present work, we focus on the homogenization of heterogeneous materials which are described at the finest scale by two different materials models (both depending on a specific characteristic length) while the homogeneous medium behaves as a classical Cauchy medium in both cases.In the first part, the random microstructure of a Cauchy medium is considered. Solving the auxiliary problem on multiple realizations can be very costly due to constitutive phases exhibiting not well-separated characteristic length scales and/or high mechanical contrasts. In order to circumvent these limitations, our study is based on a mesoscopic description of the material, combined with information theory. In the…
Advisors/Committee Members: Sab, Karam (thesis director).
Subjects/Keywords: Modélisation probabiliste; Milieux généralisés; Homogénéisation; Approche variationelle; Probabilistic modeling; Generalized continua; Homogenization; Variational approach
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Tran, V. P. (2016). Modélisation à plusieurs échelles d'un milieu continu hétérogène aléatoire : Stochastic modeling of random heterogeneous materials. (Doctoral Dissertation). Université Paris-Est. Retrieved from http://www.theses.fr/2016PESC1159
Chicago Manual of Style (16th Edition):
Tran, Vinh Phuc. “Modélisation à plusieurs échelles d'un milieu continu hétérogène aléatoire : Stochastic modeling of random heterogeneous materials.” 2016. Doctoral Dissertation, Université Paris-Est. Accessed March 07, 2021.
http://www.theses.fr/2016PESC1159.
MLA Handbook (7th Edition):
Tran, Vinh Phuc. “Modélisation à plusieurs échelles d'un milieu continu hétérogène aléatoire : Stochastic modeling of random heterogeneous materials.” 2016. Web. 07 Mar 2021.
Vancouver:
Tran VP. Modélisation à plusieurs échelles d'un milieu continu hétérogène aléatoire : Stochastic modeling of random heterogeneous materials. [Internet] [Doctoral dissertation]. Université Paris-Est; 2016. [cited 2021 Mar 07].
Available from: http://www.theses.fr/2016PESC1159.
Council of Science Editors:
Tran VP. Modélisation à plusieurs échelles d'un milieu continu hétérogène aléatoire : Stochastic modeling of random heterogeneous materials. [Doctoral Dissertation]. Université Paris-Est; 2016. Available from: http://www.theses.fr/2016PESC1159

NSYSU
7.
Chu, Hung-Jen.
Variational Approach to Pursuit-Evasion Game with Curvature Constraint.
Degree: PhD, Electrical Engineering, 2000, NSYSU
URL: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0612100-150130
► In this thesis, a pursuit-evasion game, in which the pursuer moves with simple motion whereas the evader moves at a fixed speed but with a…
(more)
▼ In this thesis, a pursuit-evasion game, in which the pursuer moves with simple motion whereas the evader moves at a fixed speed but with a curvature constraint, is investigated. The game is the inverse of the usual homicidal chauffeur game. Square of the distance between the pursuer and the evader when the game is terminated is selected as the cost function. To solve such a zero-sum game, the
variational approach will be employed to solve the problem. An algorithm will be proposed to determine a saddle point and the value of the game under consideration
Advisors/Committee Members: Jer-Guang Hsieh (committee member), Juang-Perng Su (chair), Kuang-chih Huang (chair), Tsu Tian Lee (chair), Fan-Ren Chang (chair), Rey-chue Hwang (chair).
Subjects/Keywords: Pursuit-Evasion Game; Variational Approach; Curvature Constraint
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Chu, H. (2000). Variational Approach to Pursuit-Evasion Game with Curvature Constraint. (Doctoral Dissertation). NSYSU. Retrieved from http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0612100-150130
Chicago Manual of Style (16th Edition):
Chu, Hung-Jen. “Variational Approach to Pursuit-Evasion Game with Curvature Constraint.” 2000. Doctoral Dissertation, NSYSU. Accessed March 07, 2021.
http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0612100-150130.
MLA Handbook (7th Edition):
Chu, Hung-Jen. “Variational Approach to Pursuit-Evasion Game with Curvature Constraint.” 2000. Web. 07 Mar 2021.
Vancouver:
Chu H. Variational Approach to Pursuit-Evasion Game with Curvature Constraint. [Internet] [Doctoral dissertation]. NSYSU; 2000. [cited 2021 Mar 07].
Available from: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0612100-150130.
Council of Science Editors:
Chu H. Variational Approach to Pursuit-Evasion Game with Curvature Constraint. [Doctoral Dissertation]. NSYSU; 2000. Available from: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0612100-150130

University of Michigan
8.
Kock, Ellen Diane.
Fluid-structure interaction analysis by the finite element method – a variational approach.
Degree: PhD, Mechanics, 1989, University of Michigan
URL: http://hdl.handle.net/2027.42/128428
► We have developed a finite element method for analyzing nonlinear and linear fluid-structure interaction problems by working directly from a variational indicator based on Hamilton's…
(more)
▼ We have developed a finite element method for analyzing nonlinear and linear fluid-structure interaction problems by working directly from a
variational indicator based on Hamilton's principle. We restrict our analyses to inviscid, irrotational, and isentropic fluid flows. The
variational indicator includes the fluid potential energy due to gravity which is often ignored. This and the fact that we consider our domain to be variable provides us with the capability to model free surfaces. Taking the first variation of the energy-based functional yields the nonlinear governing Euler-Lagrange equations for the fully coupled nonlinear fluid-structure problem. These equations provide the basis for developing a nonlinear finite element approximation. We also derive a linear finite element approximation which resembles several formulations already in use. Finally, we demonstrate the effectiveness of both linear and nonlinear finite element formulations in analyzing a variety of fluid-structure interaction problems.
Advisors/Committee Members: Olson, Lorraine (advisor).
Subjects/Keywords: Analysis; Approach; Element; Finite; Fluid; Interaction; Method; Structure; Variational
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Kock, E. D. (1989). Fluid-structure interaction analysis by the finite element method – a variational approach. (Doctoral Dissertation). University of Michigan. Retrieved from http://hdl.handle.net/2027.42/128428
Chicago Manual of Style (16th Edition):
Kock, Ellen Diane. “Fluid-structure interaction analysis by the finite element method – a variational approach.” 1989. Doctoral Dissertation, University of Michigan. Accessed March 07, 2021.
http://hdl.handle.net/2027.42/128428.
MLA Handbook (7th Edition):
Kock, Ellen Diane. “Fluid-structure interaction analysis by the finite element method – a variational approach.” 1989. Web. 07 Mar 2021.
Vancouver:
Kock ED. Fluid-structure interaction analysis by the finite element method – a variational approach. [Internet] [Doctoral dissertation]. University of Michigan; 1989. [cited 2021 Mar 07].
Available from: http://hdl.handle.net/2027.42/128428.
Council of Science Editors:
Kock ED. Fluid-structure interaction analysis by the finite element method – a variational approach. [Doctoral Dissertation]. University of Michigan; 1989. Available from: http://hdl.handle.net/2027.42/128428

Penn State University
9.
Kirshtein, Arkadz.
Energetic variational approaches and numerical analysis in complex fluids.
Degree: 2019, Penn State University
URL: https://submit-etda.libraries.psu.edu/catalog/17249azk194
► The main focus of my research is on mathematical modeling and numerical simulation of anisotropic complex fluids whose motion is complicated by the existence of…
(more)
▼ The main focus of my research is on mathematical modeling and numerical simulation of anisotropic complex fluids whose motion is complicated by the existence of mesoscales or sub-domain structures and interactions. Such complex fluids are ubiquitous in daily life, e.g., they arise in a wide varieties of mixtures, polymeric solutions, colloidal dispersions, biofluids, electro-rheological fluids, ionic fluids, liquid crystals, and liquid crystalline polymers. Indeed, materials modeled as complex fluids often have great practical utility since the microstructure can be manipulated by external fields or forces in order to produce useful mechanical, optical or thermal properties.
An important application of such complex fluids is the modeling of composites of different materials. The mixing of two (or more) different components can be achieved by deriving various properties from the composite. These properties of a certain composite material can be tuned to suit a particular application, e.g., by varying the composition, concentration and, in many situations, the phase morphology. The modeling of such phenomena is achieved by postulating and analyzing the energy laws of the physical systems and then applying the energetic
variational approach for isothermal systems. The advantage of such an
approach is that it provides a definitive way to derive a thermodynamically consistent model, which is of critical importance for many physical applications. The next step in such a process is to design efficient numerical simulations approximating the solutions of these advanced models in a way that they preserve the energy laws of the proposed systems. The main goal of my Ph.D. and current research on this topic is to extend the unified energetic
variational framework to a wider range of applications, such as mixtures with microstructures and various boundary effects.
To model mixtures of fluids and free boundary motion, I employ the diffuse interface method, which allows seamless integration of the free boundary into the system written on the whole domain. The main focus of my work on this topic is on investigating the effects of different forms of free energy involving phase-field functions on the dynamics of the system (with the Cahn-Hilliard equation governing dynamics of the phase-field).
To describe the behavior of mixtures with three components, one has to introduce and follow two phase-field functions, in some models introducing three linearly dependent functions (and expressing one in terms of the others). My main contribution to this area is in showing that in fundamentally different descriptions the free energies are quantitatively similar and the main difference is in the energy dissipation. Also the analysis allowed me to further the understanding of the mixing energy and introduce some additional requirements on the energy coefficients that are useful outside of three-component flow framework. To demonstrate the efficiency of the aforementioned models and further analyze them I developed decoupled…
Advisors/Committee Members: Chun Liu, Dissertation Advisor/Co-Advisor, Chun Liu, Committee Chair/Co-Chair, Andrew Leonard Belmonte, Committee Member, Anna L Mazzucato, Committee Member, Francesco Costanzo, Outside Member, James Joseph Brannick, Dissertation Advisor/Co-Advisor, Mark Levi, Program Head/Chair, James J. Brannick, Committee Chair/Co-Chair.
Subjects/Keywords: Mathematical Modeling; Complex Fluids; Fluid mechanics; Phase Field; Energetic Variational Approach; Numerical Analysis; Partial Differential Equations; Diffusive Interface Method; Sintering
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APA (6th Edition):
Kirshtein, A. (2019). Energetic variational approaches and numerical analysis in complex fluids. (Thesis). Penn State University. Retrieved from https://submit-etda.libraries.psu.edu/catalog/17249azk194
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Kirshtein, Arkadz. “Energetic variational approaches and numerical analysis in complex fluids.” 2019. Thesis, Penn State University. Accessed March 07, 2021.
https://submit-etda.libraries.psu.edu/catalog/17249azk194.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Kirshtein, Arkadz. “Energetic variational approaches and numerical analysis in complex fluids.” 2019. Web. 07 Mar 2021.
Vancouver:
Kirshtein A. Energetic variational approaches and numerical analysis in complex fluids. [Internet] [Thesis]. Penn State University; 2019. [cited 2021 Mar 07].
Available from: https://submit-etda.libraries.psu.edu/catalog/17249azk194.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Kirshtein A. Energetic variational approaches and numerical analysis in complex fluids. [Thesis]. Penn State University; 2019. Available from: https://submit-etda.libraries.psu.edu/catalog/17249azk194
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of Southern California
10.
Akopian, Vardan.
Modeling of Earth's ionosphere and variational approach for
data assimilation.
Degree: PhD, Applied Mathematics, 2008, University of Southern California
URL: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll127/id/71573/rec/4143
► The Earth's ionosphere plays an important role in wireless communication. One of the primary goals of this research is to improve the techniques for monitoring…
(more)
▼ The Earth's ionosphere plays an important role in
wireless communication. One of the primary goals of this research
is to improve the techniques for monitoring and forecasting of the
conditions of the Earth's ionosphere. The work in this thesis
focuses on modeling of the ion and electron density changes in the
Earth's ionosphere and the assimilation of remote sensing
measurements into the numerical model. The governing equations of
the ionosphere consist of equations of fluid for chemically active
plasma in the ionosphere. These equations form a system of coupled
nonlinear convection-diffusion equations. In this thesis, we
establish the well-posedness of the equations in some special
cases. We also establish the numerical stability and consistency of
the approximation. The resulting numerical model of the ionosphere
produces stable and physically meaningful predictions of densities
for all major ion species in the ionosphere. The numerical method
is used in this research as a basis for the development of
a4-dimensional
variational (4DVAR) data assimilation
approach to
help in the estimation of the driving forces in the ionosphere. The
4DVAR technique uses the adjoint
approach in the computation of the
gradient of performance functional.; In addition to theoretical
discussions on the mathematical properties of the basic ionospheric
model and its numerical implementation, extensive work has been
devoted to the validation of both the basic ionospheric model and
4DVAR implementation. In this work we demonstrate that the new
model can accurately reproduce all major characteristics of the
ionosphere and the 4DVAR
approach can be effective in determining
the crucial drivers of the Earth's ionosphere.
Advisors/Committee Members: Wang, Chunming (Committee Chair), Rosen, Gary (Committee Member), Newton, Paul K. (Committee Member).
Subjects/Keywords: ionosphere; 4DVAR; variational approach for data assimilation; modeling; GAIM
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Akopian, V. (2008). Modeling of Earth's ionosphere and variational approach for
data assimilation. (Doctoral Dissertation). University of Southern California. Retrieved from http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll127/id/71573/rec/4143
Chicago Manual of Style (16th Edition):
Akopian, Vardan. “Modeling of Earth's ionosphere and variational approach for
data assimilation.” 2008. Doctoral Dissertation, University of Southern California. Accessed March 07, 2021.
http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll127/id/71573/rec/4143.
MLA Handbook (7th Edition):
Akopian, Vardan. “Modeling of Earth's ionosphere and variational approach for
data assimilation.” 2008. Web. 07 Mar 2021.
Vancouver:
Akopian V. Modeling of Earth's ionosphere and variational approach for
data assimilation. [Internet] [Doctoral dissertation]. University of Southern California; 2008. [cited 2021 Mar 07].
Available from: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll127/id/71573/rec/4143.
Council of Science Editors:
Akopian V. Modeling of Earth's ionosphere and variational approach for
data assimilation. [Doctoral Dissertation]. University of Southern California; 2008. Available from: http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll127/id/71573/rec/4143
11.
Shabara, Mohamed A.
Energy Harvesting Using Flextensional Piezoelectric Energy Harvesters in Resonance and Off-Resonance Modes.
Degree: MS, Mechanical & Aerospace Engineering, 2020, Old Dominion University
URL: 9798678109262
;
https://digitalcommons.odu.edu/mae_etds/320
► Energy harvesting technologies are integrated into various modern devices and systems. These systems include Artificial Intelligence (AI) systems, Internet of Things (IoT), various types…
(more)
▼ Energy harvesting technologies are integrated into various modern devices and systems. These systems include Artificial Intelligence (AI) systems, Internet of Things (IoT), various types of energy harvesters are integrated in many engineering applications such as automotive, aerospace and ocean engineering. In order to develop a fully functioning stand-alone system, it is essential to integrate it with a built in power source such as a battery or a power generator. Also, in many situations, city power sources might not be available. Therefore, reliable, renewable and sustainable local power generators are desired. Piezoelectric energy harvesting (PEH) technologies, which are piezoelectric material-based devices, are one of the best candidates for this job. Piezoelectric energy harvesters convert mechanical energy from vibrating or moving objects to electrical energy. These devices have the highest capability of designing self-powered systems as they are not weather dependent and they are capable of harvesting both small or large mechanical movements into electrical energy. The piezoelectric materials are materials that generate electrical charges when mechanical stress or force is exerted on them. On the other hand, they deform when an electric voltage is applied to them. The piezoelectric-based energy harvesters are small and effective devices that promise future engineering systems to be more intelligent, reliable and environmentally friendly. Designing a piezoelectric device is cumbersome, and it is indispensable to have a comprehensive understating of many engineering disciplines before delving into designing a new device or redesigning an existing device. These disciplines include mechanical engineering, electrical engineering, materials sciences, and device physics. In this thesis, comprehensive mathematical and experimental investigations were done for modeling piezoelectric multi-later stacks and Flextensional Energy Harvesters in resonance and in off- resonance modes. For the resonance mode, mathematical and
variational approaches were used to modeling a selected piezoelectric multi-layer stack found in the market; the models are a static model, single degree of freedom model (SDOF), a distributed parameter model and a finite element model for the resonance mode, a finite element model (using ANSYS) was used to model a single and a multiple stage Flexteisonal Energy Harvester. To validate off-resonance results, previously published experimental results were used; however, for the resonance mode an experiment was carried out to validate the numerical model's results for the multi-stage Energy Harvester. As for the single stage Flextensional Energy Harvester, previously published experimental results were used to validate the finite element model. The advantages and disadvantages of different models and approaches are compared and discussed.
Advisors/Committee Members: Tian-Bing Xu, Gene Hou, Mileta Tomovic.
Subjects/Keywords: Energy harvesters; Finite element analysis; Mechanical vibrations; Modeling; Piezoelectric materials; Variational approach; Electrical and Computer Engineering; Mechanical Engineering; Power and Energy
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Shabara, M. A. (2020). Energy Harvesting Using Flextensional Piezoelectric Energy Harvesters in Resonance and Off-Resonance Modes. (Thesis). Old Dominion University. Retrieved from 9798678109262 ; https://digitalcommons.odu.edu/mae_etds/320
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Shabara, Mohamed A. “Energy Harvesting Using Flextensional Piezoelectric Energy Harvesters in Resonance and Off-Resonance Modes.” 2020. Thesis, Old Dominion University. Accessed March 07, 2021.
9798678109262 ; https://digitalcommons.odu.edu/mae_etds/320.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Shabara, Mohamed A. “Energy Harvesting Using Flextensional Piezoelectric Energy Harvesters in Resonance and Off-Resonance Modes.” 2020. Web. 07 Mar 2021.
Vancouver:
Shabara MA. Energy Harvesting Using Flextensional Piezoelectric Energy Harvesters in Resonance and Off-Resonance Modes. [Internet] [Thesis]. Old Dominion University; 2020. [cited 2021 Mar 07].
Available from: 9798678109262 ; https://digitalcommons.odu.edu/mae_etds/320.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Shabara MA. Energy Harvesting Using Flextensional Piezoelectric Energy Harvesters in Resonance and Off-Resonance Modes. [Thesis]. Old Dominion University; 2020. Available from: 9798678109262 ; https://digitalcommons.odu.edu/mae_etds/320
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
12.
Sanchez Merchante, Luis Francisco.
Learning algorithms for sparse classification : Algorithmes d'estimation pour la classification parcimonieuse.
Degree: Docteur es, Technologies de l'Information et des Systèmes, 2013, Compiègne
URL: http://www.theses.fr/2013COMP2084
► Cette thèse traite du développement d'algorithmes d'estimation en haute dimension. Ces algorithmes visent à résoudre des problèmes de discrimination et de classification, notamment, en incorporant…
(more)
▼ Cette thèse traite du développement d'algorithmes d'estimation en haute dimension. Ces algorithmes visent à résoudre des problèmes de discrimination et de classification, notamment, en incorporant un mécanisme de sélection des variables pertinentes. Les contributions de cette thèse se concrétisent par deux algorithmes, GLOSS pour la discrimination et Mix-GLOSS pour la classification. Tous les deux sont basés sur le résolution d'une régression régularisée de type "optimal scoring" avec une formulation quadratique de la pénalité group-Lasso qui encourage l'élimination des descripteurs non-significatifs. Les fondements théoriques montrant que la régression de type "optimal scoring" pénalisée avec un terme "group-Lasso" permet de résoudre un problème d'analyse discriminante linéaire ont été développés ici pour la première fois. L'adaptation de cette théorie pour la classification avec l'algorithme EM n'est pas nouvelle, mais elle n'a jamais été détaillée précisément pour les pénalités qui induisent la parcimonie. Cette thèse démontre solidement que l'utilisation d'une régression de type "optimal scoring" pénalisée avec un terme "group-Lasso" à l'intérieur d'une boucle EM est possible. Nos algorithmes ont été testés avec des bases de données réelles et artificielles en haute dimension avec des résultats probants en terme de parcimonie, et ce, sans compromettre la performance du classifieur.
This thesis deals with the development of estimation algorithms with embedded feature selection the context of high dimensional data, in the supervised and unsupervised frameworks. The contributions of this work are materialized by two algorithms, GLOSS for the supervised domain and Mix-GLOSS for unsupervised counterpart. Both algorithms are based on the resolution of optimal scoring regression regularized with a quadratic formulation of the group-Lasso penalty which encourages the removal of uninformative features. The theoretical foundations that prove that a group-Lasso penalized optimal scoring regression can be used to solve a linear discriminant analysis bave been firstly developed in this work. The theory that adapts this technique to the unsupervised domain by means of the EM algorithm is not new, but it has never been clearly exposed for a sparsity-inducing penalty. This thesis solidly demonstrates that the utilization of group-Lasso penalized optimal scoring regression inside an EM algorithm is possible. Our algorithms have been tested with real and artificial high dimensional databases with impressive resuits from the point of view of the parsimony without compromising prediction performances.
Advisors/Committee Members: Grandvalet, Yves (thesis director), Govaert, Gérard (thesis director).
Subjects/Keywords: Algorithmes d'estimation; Classification parcimonieuse; Discrimination; Variables pertinentes; Algorithmes GLOSS; Linear discriminant analysis; Feature selection; Regularization; Variational approach; Clustering; Optimal scoring; Group Lasso; Sparsity
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Sanchez Merchante, L. F. (2013). Learning algorithms for sparse classification : Algorithmes d'estimation pour la classification parcimonieuse. (Doctoral Dissertation). Compiègne. Retrieved from http://www.theses.fr/2013COMP2084
Chicago Manual of Style (16th Edition):
Sanchez Merchante, Luis Francisco. “Learning algorithms for sparse classification : Algorithmes d'estimation pour la classification parcimonieuse.” 2013. Doctoral Dissertation, Compiègne. Accessed March 07, 2021.
http://www.theses.fr/2013COMP2084.
MLA Handbook (7th Edition):
Sanchez Merchante, Luis Francisco. “Learning algorithms for sparse classification : Algorithmes d'estimation pour la classification parcimonieuse.” 2013. Web. 07 Mar 2021.
Vancouver:
Sanchez Merchante LF. Learning algorithms for sparse classification : Algorithmes d'estimation pour la classification parcimonieuse. [Internet] [Doctoral dissertation]. Compiègne; 2013. [cited 2021 Mar 07].
Available from: http://www.theses.fr/2013COMP2084.
Council of Science Editors:
Sanchez Merchante LF. Learning algorithms for sparse classification : Algorithmes d'estimation pour la classification parcimonieuse. [Doctoral Dissertation]. Compiègne; 2013. Available from: http://www.theses.fr/2013COMP2084
13.
Groza, Vladimir.
Identification de paramètres et analyses de sensibilité pour un modèle d'usinage par jet d'eau abrasif : Identification of unknown model parameters and sensitivity analysis for abrasive waterjet milling process.
Degree: Docteur es, Mathématiques, 2016, Université Côte d'Azur (ComUE)
URL: http://www.theses.fr/2016AZUR4094
► Ce travail fait partie du projet Marie-Curie ITN STEEP, dans le domaine des faisceaux énergétiques. Nous étudions ici l'identification de paramètres pour un modèle générique…
(more)
▼ Ce travail fait partie du projet Marie-Curie ITN STEEP, dans le domaine des faisceaux énergétiques. Nous étudions ici l'identification de paramètres pour un modèle générique d'usinage par jet d'eau abrasif. L'étude de ce problème trouve son origine dans les applications industrielles d'usinage, où la nécessité de modéliser et prédire la surface finale avec une très grande précision est essentielle en l'absence de connaissance des paramètres du modèle Nous proposons ici une méthode d'identification des paramètres du modèle basée sur la minimisation d'une fonction coût, mesurant la différence entre la solution numérique et les observations expérimentales. L'approche variationnelle, basée sur le Lagrangien, permet de considérer l'adjoint, et l'utilisation d'un logiciel de différentiation automatique (TAPENADE) conduit à une identification rapide et précise des paramètres, quelles que soient la complexité et la taille du problème étudié. La qualité de l'identification peut être fortement instable et dépendre largement des données expérimentales en cas de bruit. Nous introduisons alors des termes de régularisation permettant de gérer la présence d'erreurs de mesure. Plusieurs cas d'usinage par jet abrasif sont considérés: problème stationnaire, jet qui se déplace à vitesse constante, ou en accélérant, utilisation synthétiques ou réelles L'étude de sensibilité montre la robustesse de l'approche, qui permet d'obtenir de très bons résultats acceptables d'un point de vue industriel
This work is part of STEEP Marie-Curie ITN project, covering the research in field of energy beam processing. We focus on the identification of unknown parameters of the proposed generic Abrasive WaterJet Milling (AWJM) model. The necessity of studying this problem comes from the industrial milling applications where the possibility to predict and model the final surface with high accuracy is one of the primary tasks in the absence of any knowledge of the model parameters that should be used. We propose the method of the model parameters identification by minimizing a cost function, measuring the difference between experimental observation and numerical solution. The variational approach based on corresponding Lagrangian allows to obtain the adjoint state and the involvement of the automatic differentiation software tool (TAPENADE) leads to fast and efficient parameters identification. In fact the parameter identification problem is highly unstable and strictly depends on quality of input data. Regularization terms could be effectively used to deal with the presence of measurement errors. Various cases of the AWJM process such as a stationary problem and moving with constant feed speed or acceleration are studied based on both artificial and real experimental data. The sensitivity study related to these particular problems demonstrates the strong capability of the proposed approach to obtain acceptable
Advisors/Committee Members: Auroux, Didier (thesis director).
Subjects/Keywords: Équations aux dérivées partielles; Problèmes inverses; Approche variationnelle; Identification de paramètres; Usinage par jet d'eau abrasif; Partial differential equations; Inverse problems; Variational approach; Parameters identification; Brasive waterjet milling
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Groza, V. (2016). Identification de paramètres et analyses de sensibilité pour un modèle d'usinage par jet d'eau abrasif : Identification of unknown model parameters and sensitivity analysis for abrasive waterjet milling process. (Doctoral Dissertation). Université Côte d'Azur (ComUE). Retrieved from http://www.theses.fr/2016AZUR4094
Chicago Manual of Style (16th Edition):
Groza, Vladimir. “Identification de paramètres et analyses de sensibilité pour un modèle d'usinage par jet d'eau abrasif : Identification of unknown model parameters and sensitivity analysis for abrasive waterjet milling process.” 2016. Doctoral Dissertation, Université Côte d'Azur (ComUE). Accessed March 07, 2021.
http://www.theses.fr/2016AZUR4094.
MLA Handbook (7th Edition):
Groza, Vladimir. “Identification de paramètres et analyses de sensibilité pour un modèle d'usinage par jet d'eau abrasif : Identification of unknown model parameters and sensitivity analysis for abrasive waterjet milling process.” 2016. Web. 07 Mar 2021.
Vancouver:
Groza V. Identification de paramètres et analyses de sensibilité pour un modèle d'usinage par jet d'eau abrasif : Identification of unknown model parameters and sensitivity analysis for abrasive waterjet milling process. [Internet] [Doctoral dissertation]. Université Côte d'Azur (ComUE); 2016. [cited 2021 Mar 07].
Available from: http://www.theses.fr/2016AZUR4094.
Council of Science Editors:
Groza V. Identification de paramètres et analyses de sensibilité pour un modèle d'usinage par jet d'eau abrasif : Identification of unknown model parameters and sensitivity analysis for abrasive waterjet milling process. [Doctoral Dissertation]. Université Côte d'Azur (ComUE); 2016. Available from: http://www.theses.fr/2016AZUR4094
14.
Pham, Tuan Hiep.
Modélisation analytique et simulation numérique de la nucléation et de la propagation de la fissure cohésive couplée avec la plasticité : Analytical modelisation and numerical simulation of the nucleation and the propagation of cohesive crack coupled with plasticity.
Degree: Docteur es, Mécanique des solides, 2016, Université Paris-Saclay (ComUE)
URL: http://www.theses.fr/2016SACLX001
► L’objectif de cette thèse est d’étudier l’évolution de la fissure sous les effets de plasticité et du champ de contrainte non-uniforme à l’aide du modèle…
(more)
▼ L’objectif de cette thèse est d’étudier l’évolution de la fissure sous les effets de plasticité et du champ de contrainte non-uniforme à l’aide du modèle de zone cohésive. Dans un premier temps, l’évolution de la fissure au sein du matériau élastoplastique est explorée dans le cadre de l’approche variationnelle. Les solutions sont explicitées dans le cas d’une barre 1D sous traction simple grâce aux conditions de stabilité locale d’énergie au premier ordre et au second ordre. Cette étude nous permet de mettre en lumière l’effet de la plasticité sur le comportementadoucissant du matériau dès que la fissure cohésive apparaît. En effet, la réponse globale de la barre sous déplacement imposé est stable seulement si la longueur de la barre est inférieure à une longueur critique. Cette dernière est démontrée indépendante du module d’écrouissage plastique mais dépend du module Young et de la dérivée seconde de la densité d’énergie de fissure. Les formulations énergétiques peuvent être généralisées pour la structure 3D. Dans ce cas, les critères de plasticité et de cohésif deviennent les courbes dans le plan des contraintes de Mohr. La comparaison des courbes nous permet d’étudier la nucléation de fissure cohésive au sein du domaine plastifié. Dans un deuxième temps, les effets de la non-uniformité du champ de contrainte sur la nucléation de la fissure au sein de la structure élastique sont mis en évidence. On construit la solution analytique en utilisant la technique à deux échelles et l’analyse complexe. L’évolution de la fissure purement cohésive et partiellement non-cohésive est contrôlée par le gradient du champ de contrainte lié à une longueur caractéristique. L’utilisation des différentes lois cohésives dans le problème est explorée. La sensibilité de la solution à la taille du défaut préexistant est également étudiée. Finalement, des résultats analytiques sont validés par les simulations numériques et le modèle de zone cohésive en mode mixte est implémenté dans Code_Aster.
The aims of this work is to study the cracks evolution under plasticity and nonuniform stress field effects by using cohesive zone model. Firstly, basing on the variational approach, the crack evolution in the elastoplastic material is investigated. The solutions for 1D beam under simple tension is expressed explicitly through the first and the second orders stability conditions of energy. This study shows us the plasticity effects on the material softening behavior as soon as crack appears. In fact, the global solution of the beam under described displacement is stable only if the beam length is lower than a characteristic length. This length is independent of plasticity hardening module but depends on Young modulus and on the second derivative of crack energy density. The energy formulations can be generalized for 3D structure. In this case, the plasticity and cohesive criteria become two curves in Mohr’s stresses plane. The comparison between theses curves allows us to consider the crack nucleation in the plastified domain. Secondly, the…
Advisors/Committee Members: Marigo, Jean-Jacques (thesis director).
Subjects/Keywords: Modèles de zone cohésive; Plasticité; Gradient de contrainte; Approche variationnelle; Technique à deux échelle; Analyse complexe; Cohesive zone model; Plasticity; Stress gradient; Variational approach; Two-Scales technique; Complex analysis
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Pham, T. H. (2016). Modélisation analytique et simulation numérique de la nucléation et de la propagation de la fissure cohésive couplée avec la plasticité : Analytical modelisation and numerical simulation of the nucleation and the propagation of cohesive crack coupled with plasticity. (Doctoral Dissertation). Université Paris-Saclay (ComUE). Retrieved from http://www.theses.fr/2016SACLX001
Chicago Manual of Style (16th Edition):
Pham, Tuan Hiep. “Modélisation analytique et simulation numérique de la nucléation et de la propagation de la fissure cohésive couplée avec la plasticité : Analytical modelisation and numerical simulation of the nucleation and the propagation of cohesive crack coupled with plasticity.” 2016. Doctoral Dissertation, Université Paris-Saclay (ComUE). Accessed March 07, 2021.
http://www.theses.fr/2016SACLX001.
MLA Handbook (7th Edition):
Pham, Tuan Hiep. “Modélisation analytique et simulation numérique de la nucléation et de la propagation de la fissure cohésive couplée avec la plasticité : Analytical modelisation and numerical simulation of the nucleation and the propagation of cohesive crack coupled with plasticity.” 2016. Web. 07 Mar 2021.
Vancouver:
Pham TH. Modélisation analytique et simulation numérique de la nucléation et de la propagation de la fissure cohésive couplée avec la plasticité : Analytical modelisation and numerical simulation of the nucleation and the propagation of cohesive crack coupled with plasticity. [Internet] [Doctoral dissertation]. Université Paris-Saclay (ComUE); 2016. [cited 2021 Mar 07].
Available from: http://www.theses.fr/2016SACLX001.
Council of Science Editors:
Pham TH. Modélisation analytique et simulation numérique de la nucléation et de la propagation de la fissure cohésive couplée avec la plasticité : Analytical modelisation and numerical simulation of the nucleation and the propagation of cohesive crack coupled with plasticity. [Doctoral Dissertation]. Université Paris-Saclay (ComUE); 2016. Available from: http://www.theses.fr/2016SACLX001
15.
LE NGOC THUY.
Line-Field Based Adaptive Image Model for Blind Deblurring.
Degree: 2010, National University of Singapore
URL: http://scholarbank.nus.edu.sg/handle/10635/23789
Subjects/Keywords: blind deblurring; line field; LiFeAIM; Variational Bayesian approach; circulant matrix; cross validation
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❌
APA ·
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CSE |
Export
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Manager
APA (6th Edition):
THUY, L. N. (2010). Line-Field Based Adaptive Image Model for Blind Deblurring. (Thesis). National University of Singapore. Retrieved from http://scholarbank.nus.edu.sg/handle/10635/23789
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
THUY, LE NGOC. “Line-Field Based Adaptive Image Model for Blind Deblurring.” 2010. Thesis, National University of Singapore. Accessed March 07, 2021.
http://scholarbank.nus.edu.sg/handle/10635/23789.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
THUY, LE NGOC. “Line-Field Based Adaptive Image Model for Blind Deblurring.” 2010. Web. 07 Mar 2021.
Vancouver:
THUY LN. Line-Field Based Adaptive Image Model for Blind Deblurring. [Internet] [Thesis]. National University of Singapore; 2010. [cited 2021 Mar 07].
Available from: http://scholarbank.nus.edu.sg/handle/10635/23789.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
THUY LN. Line-Field Based Adaptive Image Model for Blind Deblurring. [Thesis]. National University of Singapore; 2010. Available from: http://scholarbank.nus.edu.sg/handle/10635/23789
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
16.
Pethe, Rohit.
Variational h-adaptation for strongly coupled problems in thermo-mechanics : Adaptation variationnelle pour des problèmes fortement couplés en thermo-mécanique.
Degree: Docteur es, Génie mécanique, 2017, Ecole centrale de Nantes
URL: http://www.theses.fr/2017ECDN0046
► Une approche d'adaptation en mesh pour des problèmes fortement couplés est proposée, selon un principe variationnel. La technique d'adaptation repose sur une erreur indiquée par…
(more)
▼ Une approche d'adaptation en mesh pour des problèmes fortement couplés est proposée, selon un principe variationnel. La technique d'adaptation repose sur une erreur indiquée par un potentiel énergétique et est donc exempte d'estimations d'erreur. Selon la nature du point de chevauchement de ce principe variationnel, une solution de solution décalée apparaît plus naturelle et conduit à une adaptation de maille distincte pour les champs mécaniques et thermiques. En utilisant différents maillons pour différents phénomènes, des solutions précises pour différents domaines à l'étude sont obtenues. Les variables internes sont considérées comme constantes par rapport aux cellules de Voronoi, de sorte qu'aucune procédure de remappage complexe n'est nécessaire pour transférer des variables internes. Étant donné que l'algorithme est basé sur un ensemble de paramètres de tolérance, des analyses paramétriques et une étude de leur influence respective sur l'adaptation de maille sont réalisées. Cette analyse détaillée est effectuée sur des problèmes unidimensionnels. La méthode proposée se révèle être rentable qu'un maillage uniforme, certaines applications de l'approche proposée pour différents exemples 2D, y compris les bandes de cisaillement et le soudage par friction, sont présentées.
A mesh adaption approach for strongly coupled problems is proposed, based on a variational principle. The adaption technique relies on error indicated by an energy-like potential and is hence free from error estimates. According to the saddle point nature of this variational principle, a staggered solution approach appears more natural and leads to separate mesh adaption for mechanical and thermal fields. Using different meshes for different phenomena, precise solutions for various fields under consideration are obtained. Internal variables are considered constant over Voronoi cells, so no complex remapping procedures are necessary to transfer internal variables. Since the algorithm is based on a set of tolerance parameters, parametric analyses and a study of their respective influence on the mesh adaption is carried out. This detailed analysis is performed on uni-dimensional problems. The proposed method is shown to be cost effective than uniform meshing, some applications of the proposed approach to various 2D examples including shear bands and friction welding are presented.
Advisors/Committee Members: Stainier, Laurent (thesis director).
Subjects/Keywords: Adaptions de maillage; Approche variationnel; Problèmes couplée; Thermomécanique; Multiphysique; Problèmes non-linaire; Mesh adaptation; Variational approach; Strongly coupled problems; Thermo-mechanics; Multiphysics; Non linear coupled problems
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Pethe, R. (2017). Variational h-adaptation for strongly coupled problems in thermo-mechanics : Adaptation variationnelle pour des problèmes fortement couplés en thermo-mécanique. (Doctoral Dissertation). Ecole centrale de Nantes. Retrieved from http://www.theses.fr/2017ECDN0046
Chicago Manual of Style (16th Edition):
Pethe, Rohit. “Variational h-adaptation for strongly coupled problems in thermo-mechanics : Adaptation variationnelle pour des problèmes fortement couplés en thermo-mécanique.” 2017. Doctoral Dissertation, Ecole centrale de Nantes. Accessed March 07, 2021.
http://www.theses.fr/2017ECDN0046.
MLA Handbook (7th Edition):
Pethe, Rohit. “Variational h-adaptation for strongly coupled problems in thermo-mechanics : Adaptation variationnelle pour des problèmes fortement couplés en thermo-mécanique.” 2017. Web. 07 Mar 2021.
Vancouver:
Pethe R. Variational h-adaptation for strongly coupled problems in thermo-mechanics : Adaptation variationnelle pour des problèmes fortement couplés en thermo-mécanique. [Internet] [Doctoral dissertation]. Ecole centrale de Nantes; 2017. [cited 2021 Mar 07].
Available from: http://www.theses.fr/2017ECDN0046.
Council of Science Editors:
Pethe R. Variational h-adaptation for strongly coupled problems in thermo-mechanics : Adaptation variationnelle pour des problèmes fortement couplés en thermo-mécanique. [Doctoral Dissertation]. Ecole centrale de Nantes; 2017. Available from: http://www.theses.fr/2017ECDN0046
17.
Siala, Hana.
Tolérancement fonctionnel généralisé et intégration dans une approche d’ingénierie système : Functional generalized tolerancing and integration into an approach of systems engineering.
Degree: Docteur es, Ingéniérie des systèmes complexes, 2020, université Paris-Saclay; Université de Sfax (Tunisie)
URL: http://www.theses.fr/2020UPASC015
► Pour un système mécatronique, le manque de robustesse est principalement dû à une ignorance de la variabilité qui est inévitable dans tout système conçu, à…
(more)
▼ Pour un système mécatronique, le manque de robustesse est principalement dû à une ignorance de la variabilité qui est inévitable dans tout système conçu, à toutes les étapes de son développement et tout au long de son cycle de vie. En effet, les imperfections inhérentes aux processus de fabrication et les variations en fonctionnement telles que l'usure des matériaux ou les effets physiques multiples (thermiques, vibrations, etc.) impliquent des variations paramétriques susceptibles de dégrader le bon fonctionnement du système. Pour garantir un niveau de qualité élevé et pour améliorer la robustesse de la conception, les déviations entre les valeurs réelles et les valeurs nominales des paramètres et des variables doivent être limitées par des tolérances bien spécifiées.Pour ce faire, il est important de comprendre la relation entre les écarts des paramètres et le comportement du système. Ainsi, dans cette thèse, une approche variationnelle est proposée pour spécifier les tolérances admissibles des paramètres pour lesquels le comportement reste conforme aux spécifications. De plus, cette approche est utilisée pour identifier la sensibilité des performances du système aux écarts des paramètres dans un système mécatronique. Cette analyse de sensibilité vise à déterminer les paramètres agissant de manière significative sur le bon fonctionnement du système et son comportement. L’approche proposée est appliquée à un exemple dans le domaine de l’aéronautique : un actionneur électromécanique entraînant une surface de contrôle de vol primaire d’un aéronef (aileron).
For a mechatronic system, the lack of robustness is mainly due to an ignorance of variability which is unavoidable in every designed system at all stages of its development and during its entire life cycle. In fact, the inherent imperfections of manufacturing processes and operational variations such as material wear or multi-physical effects (thermal, vibrations, etc.) involve parametric variations, which can degrade the proper system function. To ensure a high level of quality and to improve design robustness, the deviations between actual and target definition should be restricted by specified tolerances. Moreover, it is important to understand the relationship between parameters deviations and system behavior. Thus, in this thesis, a variational approach is proposed to specify the admissible parameters deviations for which the given specifications can be guaranteed. Furthermore, this approach is used to identify performances sensitivity to parameters deviations in a mechatronic system and to determine influential parameters that affect significantly the proper functioning of the system and its behavior. The complete approach is applied to an example in the aeronautic field: an electromechanical actuator driving an aircraft primary flight control surface (aileron).
Advisors/Committee Members: Choley, Jean-Yves (thesis director), Louati, Jamel (thesis director).
Subjects/Keywords: Système mécatronique; Variation paramétrique; Synthèse de tolérance; Approche variationnelle; Analyse de sensibilité; Actionneur électromécanique (EMA); Mechatronic system; Parameter variation; Tolerance synthesis; Variational approach; Sensitivity analysis; Electromechanical actuator (EMA)
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Siala, H. (2020). Tolérancement fonctionnel généralisé et intégration dans une approche d’ingénierie système : Functional generalized tolerancing and integration into an approach of systems engineering. (Doctoral Dissertation). université Paris-Saclay; Université de Sfax (Tunisie). Retrieved from http://www.theses.fr/2020UPASC015
Chicago Manual of Style (16th Edition):
Siala, Hana. “Tolérancement fonctionnel généralisé et intégration dans une approche d’ingénierie système : Functional generalized tolerancing and integration into an approach of systems engineering.” 2020. Doctoral Dissertation, université Paris-Saclay; Université de Sfax (Tunisie). Accessed March 07, 2021.
http://www.theses.fr/2020UPASC015.
MLA Handbook (7th Edition):
Siala, Hana. “Tolérancement fonctionnel généralisé et intégration dans une approche d’ingénierie système : Functional generalized tolerancing and integration into an approach of systems engineering.” 2020. Web. 07 Mar 2021.
Vancouver:
Siala H. Tolérancement fonctionnel généralisé et intégration dans une approche d’ingénierie système : Functional generalized tolerancing and integration into an approach of systems engineering. [Internet] [Doctoral dissertation]. université Paris-Saclay; Université de Sfax (Tunisie); 2020. [cited 2021 Mar 07].
Available from: http://www.theses.fr/2020UPASC015.
Council of Science Editors:
Siala H. Tolérancement fonctionnel généralisé et intégration dans une approche d’ingénierie système : Functional generalized tolerancing and integration into an approach of systems engineering. [Doctoral Dissertation]. université Paris-Saclay; Université de Sfax (Tunisie); 2020. Available from: http://www.theses.fr/2020UPASC015

University of Waterloo
18.
Zhu, Dian.
General Quadratic Risk Minimization: a Variational Approach.
Degree: 2016, University of Waterloo
URL: http://hdl.handle.net/10012/10574
► Mean-variance portfolio selection and mean-variance hedging are mainstream research topics in mathematical nance, which can be subsumed within the framework of a general problem of…
(more)
▼ Mean-variance portfolio selection and mean-variance hedging are mainstream research
topics in mathematical nance, which can be subsumed within the framework of a general
problem of quadratic risk minimization. We study this quadratic risk minimization problem
in the setting of an Ito process market model with random market parameters. Our particular
contribution is to introduce a combination of constraints on both the trading strategy
(i.e. portfolio) and the wealth process, which includes in particular portfolio insurance in
the form of a stipulated lower-bound on the wealth process over the entire trading interval
(this is also called an American wealth constraint). The result is a stochastic control problem
which includes the combination of a portfolio constraint (i.e. a \control constraint")
and a wealth constraint over the trading interval (i.e. a \state constraint"). The goal
of the present thesis is to address this stochastic control problem. Even in the setting
of deterministic (or non-random) optimal control it is well known that a combination of
control constraints and state constraints over the control interval presents some particular
challenges, and of course these challenges increase considerably for stochastic control problems
with the same combination of constraints. In this thesis we shall take advantage of
the convexity of the problem and apply a powerful variational method of Rockafellar which
has proved to be very e ective in the deterministic optimal control of partial di erential
equations, convex optimization in continuum mechanics, and stochastic convex programming
over nite dimensional spaces. The variational approach of Rockafellar enables one
to systematically construct an appropriate vector space of dual variables, together with a
dual problem on this space of dual variables, and gives conditions which ensure that there
is zero duality gap (i.e. the values of the primal and dual problems are equal) as well as
existence of a solution of the dual problem (i.e. existence of Lagrange multipliers for the
constraints in the problem). The key to applying the Rockafellar variational approach to
the stochastic control problem outlined above turns out to be a mild feasibility condition
on the wealth process which is very reminiscent of \Slater-type" conditions familiar from
convex optimization. With this condition in place we are able to construct an associated
dual problem, and establish existence of a solution of the dual problem, together with
Kuhn-Tucker optimality conditions which relate putative solutions of the primal and dual
problems. We then use these optimality conditions to construct an optimal portfolio in
terms of the solution of the dual problem.
Subjects/Keywords: quadratic loss minimization; portfolio selection; American wealth constraint; European wealth constraint; Portfolio constraint; Stochastic Control; Convex optimization; Conjugate duality; Slater condition; Singular linear functionals; Lagrange multipliers; variational approach
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Zhu, D. (2016). General Quadratic Risk Minimization: a Variational Approach. (Thesis). University of Waterloo. Retrieved from http://hdl.handle.net/10012/10574
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Zhu, Dian. “General Quadratic Risk Minimization: a Variational Approach.” 2016. Thesis, University of Waterloo. Accessed March 07, 2021.
http://hdl.handle.net/10012/10574.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Zhu, Dian. “General Quadratic Risk Minimization: a Variational Approach.” 2016. Web. 07 Mar 2021.
Vancouver:
Zhu D. General Quadratic Risk Minimization: a Variational Approach. [Internet] [Thesis]. University of Waterloo; 2016. [cited 2021 Mar 07].
Available from: http://hdl.handle.net/10012/10574.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Zhu D. General Quadratic Risk Minimization: a Variational Approach. [Thesis]. University of Waterloo; 2016. Available from: http://hdl.handle.net/10012/10574
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Louisiana State University
19.
Mesgarnejad, Ataollah.
Applications of the Variational Approach to Fracture Mechanics.
Degree: PhD, Mechanical Engineering, 2014, Louisiana State University
URL: etd-11152014-101222
;
https://digitalcommons.lsu.edu/gradschool_dissertations/2776
► In this study we present the variational approach to fracture mechanics as a versatile tool for the modeling of the fracture phenomenon in solids. Variational…
(more)
▼ In this study we present the variational approach to fracture mechanics as a versatile tool for the modeling of the fracture phenomenon in solids. Variational fracture mechanics restates the problem of initiation and propagation of cracks in solids as an energy minimization problem. The edifice of this energy minimization problem is such that unlike other methods (e.g. extended finite element method XFEM, cohesive-zone methods) the variational approach to fracture mechanics, diminishes the need for an a priori knowledge of the crack path or ad hoc assumptions in the form of path selection laws. We will show applications of the variational approach to fracture mechanics to the thin-film and the classical two and three dimensional elasticity settings and to simulation of double-torsion experiments.
Subjects/Keywords: Variational approach to fracture; Brittle fracture; Fracture mechanics; phase-field methods; Thin films; Dimension reduction; Double-torsion experiments; Finite element method; Computational solid mechanics
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Mesgarnejad, A. (2014). Applications of the Variational Approach to Fracture Mechanics. (Doctoral Dissertation). Louisiana State University. Retrieved from etd-11152014-101222 ; https://digitalcommons.lsu.edu/gradschool_dissertations/2776
Chicago Manual of Style (16th Edition):
Mesgarnejad, Ataollah. “Applications of the Variational Approach to Fracture Mechanics.” 2014. Doctoral Dissertation, Louisiana State University. Accessed March 07, 2021.
etd-11152014-101222 ; https://digitalcommons.lsu.edu/gradschool_dissertations/2776.
MLA Handbook (7th Edition):
Mesgarnejad, Ataollah. “Applications of the Variational Approach to Fracture Mechanics.” 2014. Web. 07 Mar 2021.
Vancouver:
Mesgarnejad A. Applications of the Variational Approach to Fracture Mechanics. [Internet] [Doctoral dissertation]. Louisiana State University; 2014. [cited 2021 Mar 07].
Available from: etd-11152014-101222 ; https://digitalcommons.lsu.edu/gradschool_dissertations/2776.
Council of Science Editors:
Mesgarnejad A. Applications of the Variational Approach to Fracture Mechanics. [Doctoral Dissertation]. Louisiana State University; 2014. Available from: etd-11152014-101222 ; https://digitalcommons.lsu.edu/gradschool_dissertations/2776
20.
De Anda Salazar, Jorge.
Development of variational models and algorithmic strategies for coupled problems : Développement de modèles variationnels et de stratégies algorithmiques pour les problèmes couplés.
Degree: Docteur es, Mécanique des Solides, des Matériaux, des structures et des surfaces, 2019, Ecole centrale de Nantes
URL: http://www.theses.fr/2019ECDN0058
► Une approche de modélisation et des techniques de résolution de problèmes couplés sont proposées, basées sur un principe variationnel. La modélisation repose sur une approche…
(more)
▼ Une approche de modélisation et des techniques de résolution de problèmes couplés sont proposées, basées sur un principe variationnel. La modélisation repose sur une approche variationnelle utilisée dans des types spécifiques de problèmes couplés. Le modèle proposé est généralisé pour les problèmes couplés indépendamment des types de physique sur lesquels ils s'appuient. Différentes stratégies de solutions numériques sont dérivées du modèle variationnel proposé. Ces stratégies peuvent être liées à des stratégies empiriques telles que des approches “global/local” et/ou “staggered”. Les modèles proposés et les techniques de résolution sont présentés pour différents exemples 1D. Le modèle généralisé est utilisé en électrochimie et un modèle variationnel pour une batterie lithium-ion est dérivé. Le cadre variationnel est également utilisé pour comparer différents modèles existants pour l'électrolyte de la batterie.
A modeling approach and numericalsolution techniques for coupled problems are proposed based on variational principles. The modeling is based on a variational approach used in specific types of coupled problems. The proposed model is generalized for coupled problems independently of the types of physics on which they are based. Different numerical solution strategies are derived from the proposed variational models. These strategies can be linked to empirical strategies such as « global/local" and/or « staggered" approaches. The proposed models and the resolution techniques are presented for different 1D examples. The generalized model is used in electrochemistry and a variational model for a lithium-ion battery is derived. The variational framework is also used to compare different existing models for the battery electrolyte.
Advisors/Committee Members: Stainier, Laurent (thesis director).
Subjects/Keywords: Méthodes variationnelles; Électrochimie; Problèmes couplés non linéaires; Multiphysique; Stratégies numériques; Préconditionneurs de blocs; Variational approach; Electrochemistry; Nonlinear coupled problems; Multiphysics; Staggered; Strategies; Nested strategies; Block-preconditioners
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
De Anda Salazar, J. (2019). Development of variational models and algorithmic strategies for coupled problems : Développement de modèles variationnels et de stratégies algorithmiques pour les problèmes couplés. (Doctoral Dissertation). Ecole centrale de Nantes. Retrieved from http://www.theses.fr/2019ECDN0058
Chicago Manual of Style (16th Edition):
De Anda Salazar, Jorge. “Development of variational models and algorithmic strategies for coupled problems : Développement de modèles variationnels et de stratégies algorithmiques pour les problèmes couplés.” 2019. Doctoral Dissertation, Ecole centrale de Nantes. Accessed March 07, 2021.
http://www.theses.fr/2019ECDN0058.
MLA Handbook (7th Edition):
De Anda Salazar, Jorge. “Development of variational models and algorithmic strategies for coupled problems : Développement de modèles variationnels et de stratégies algorithmiques pour les problèmes couplés.” 2019. Web. 07 Mar 2021.
Vancouver:
De Anda Salazar J. Development of variational models and algorithmic strategies for coupled problems : Développement de modèles variationnels et de stratégies algorithmiques pour les problèmes couplés. [Internet] [Doctoral dissertation]. Ecole centrale de Nantes; 2019. [cited 2021 Mar 07].
Available from: http://www.theses.fr/2019ECDN0058.
Council of Science Editors:
De Anda Salazar J. Development of variational models and algorithmic strategies for coupled problems : Développement de modèles variationnels et de stratégies algorithmiques pour les problèmes couplés. [Doctoral Dissertation]. Ecole centrale de Nantes; 2019. Available from: http://www.theses.fr/2019ECDN0058
21.
Hurst, Jerome.
Ultrafast spin dynamics in ferromagnetic thin films : Dynamique ultra-rapide de spin dans des films ferromagnétiques.
Degree: Docteur es, Physique de la matière condensée, 2017, Université de Strasbourg
URL: http://www.theses.fr/2017STRAE004
► Dans cette thèse, on s’intéresse à l'étude théorique et à la simulation numérique de la dynamique de charges et de spins dans des nano-structures métalliques.…
(more)
▼ Dans cette thèse, on s’intéresse à l'étude théorique et à la simulation numérique de la dynamique de charges et de spins dans des nano-structures métalliques. Ces dernières années la physique des nano-structures métalliques à connu un intérêt croissant, aussi bien d'un point de vue de la physique fondamental que d'un point de vue des applications technologiques. Il est donc essentiel d'avoir des modèles théoriques nous permettant de décrire correctement ce type d'objets. Cette thèse comporte deux études distinctes. Dans un premier temps on utilise un modèle semi-classique dans l'espace des phases afin d'étudier la dynamique de charges et de spins dans des films ferromagnétiques(Nickel). On décrit dans le même modèle le magnétisme itinérant et le magnétisme localisé. On montre qu'il est possible, en excitant le système avec un laser pulsé femtoseconde dans le domaine du visible, de créer un courant de spin oscillant dans la direction normal du film sur des temps ultrarapides(femtoseconde). Dans un second temps on s’intéresse à la dynamique de charge d'électrons confinés dans des nano-particules d'Or ou bien encore par des potentiels anisotropes. On montre que de telles systèmes sont des candidats intéressant pour faire de la génération d'harmoniques.
In this thesis we focus on the theoritical description and on the numerical simulation of the charge and spin dynamics in metallic nano-structures. The physics of metallic nano-structures has stimulated a huge amount of scientific interest in the last two decades, both for fundamental research and for potential technological applications. The thesis is divided in two parts. In the first part we use a semiclassical phase-space model to study the ultrafast charge and spin dynamics in thin ferromagnetic films (Nickel). Both itinerant and localized magnetism are taken into account. It is shown that an oscillating spin current can be generated in the film via the application of a femtosecond laser pulse in the visible range. In the second part we focus on the charge dynamics of electrons confined in metallic nano-particles (Gold) or anisotropic wells. We show that such systems can be used for high harmonic generation.
Advisors/Committee Members: Hervieux, Paul-Antoine (thesis director), Manfredi, Giovanni (thesis director).
Subjects/Keywords: Dynamique de spin; Magnétisme ultra-rapide; Méthode dans l’espace des phases; Équations de Wigner/Vlasov; Courant de spin; Dynamique non linéaire; Approche variationnelle; Génération d'harmoniques; Spin dynamics; Ultrafast magnetism; Phase-space methods; Wigner/Vlasov equation; Spin current; Nonlinear dynamics; Variational approach; High harmonic generation; 530.4
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Hurst, J. (2017). Ultrafast spin dynamics in ferromagnetic thin films : Dynamique ultra-rapide de spin dans des films ferromagnétiques. (Doctoral Dissertation). Université de Strasbourg. Retrieved from http://www.theses.fr/2017STRAE004
Chicago Manual of Style (16th Edition):
Hurst, Jerome. “Ultrafast spin dynamics in ferromagnetic thin films : Dynamique ultra-rapide de spin dans des films ferromagnétiques.” 2017. Doctoral Dissertation, Université de Strasbourg. Accessed March 07, 2021.
http://www.theses.fr/2017STRAE004.
MLA Handbook (7th Edition):
Hurst, Jerome. “Ultrafast spin dynamics in ferromagnetic thin films : Dynamique ultra-rapide de spin dans des films ferromagnétiques.” 2017. Web. 07 Mar 2021.
Vancouver:
Hurst J. Ultrafast spin dynamics in ferromagnetic thin films : Dynamique ultra-rapide de spin dans des films ferromagnétiques. [Internet] [Doctoral dissertation]. Université de Strasbourg; 2017. [cited 2021 Mar 07].
Available from: http://www.theses.fr/2017STRAE004.
Council of Science Editors:
Hurst J. Ultrafast spin dynamics in ferromagnetic thin films : Dynamique ultra-rapide de spin dans des films ferromagnétiques. [Doctoral Dissertation]. Université de Strasbourg; 2017. Available from: http://www.theses.fr/2017STRAE004
22.
Santos, Flávia Milo dos.
Impacto hidrodinâmico vertical de corpos axissimétricos através de uma abordagem variacional.
Degree: PhD, Engenharia de Controle e Automação Mecânica, 2013, University of São Paulo
URL: http://www.teses.usp.br/teses/disponiveis/3/3152/tde-22092014-110644/
;
► Do ponto de vista da hidrodinâmica clássica, o problema de impacto hidrodinâmico configura-se como um problema de contorno com fronteiras móveis cuja posição deve ser…
(more)
▼ Do ponto de vista da hidrodinâmica clássica, o problema de impacto hidrodinâmico configura-se como um problema de contorno com fronteiras móveis cuja posição deve ser determinada simultaneamente à solução da equação de campo. Essa característica traz dificuldades para obtenção de soluções analíticas e numéricas. Nesse sentido, o presente trabalho propõe o desenvolvimento de um método numérico específico para analisar o problema de impacto hidrodinâmico de corpos sólidos rígidos contra a superfície livre da água. A solução da equação dinâmica não linear do problema de impacto depende da determinação do tensor de massa adicional a cada instante de tempo, o qual depende da posição e atitude do corpo no instante considerado. Um método variacional específico é empregado, através do qual os coeficientes de massa adicional são determinados com erro de segunda ordem, na posição considerada. Tal método é exemplo de técnicas numéricas dessingularizadas, através das quais o potencial de velocidade é aproximado em um espaço finito-dimensional formado por funções-teste derivadas de soluções potenciais elementares, tais como pólos, dipolos, anéis de dipolos, de vórtices, etc. O problema potencial de impacto hidrodinâmico, que se caracteriza pela dominância das forças de inércia, é formulado admitindo-se a superfície líquida como equipotencial, o que permite a analogia com o limite assintótico de frequência infinita do problema de radiação de ondas causada pelo movimento de corpos flutuantes. O método desenvolvido é então aplicado ao caso de impacto vertical de corpos axissimétricos, formulando o problema sob o chamado modelo de von Kármán generalizado (GvKM). Nesse modelo as condições de contorno na geometria exata do corpo são satisfeitas, porém os efeitos do empilhamento de água junto às raízes do jato, que se forma ao longo da intersecção com a superfície livre, não são considerados no caso geral. Resultados numéricos do coeficiente de massa adicional para uma família de esferoides são apresentados e tabulados para o pronto uso em análise e projeto. Além disso, considerações acerca da inclusão do efeito de empilhamento de água junto às raízes do jato, ou seja, da elevação da superfície livre são também feitas para o caso de esferas, fazendo uso de abordagens analíticas encontradas na literatura especializada.
In terms of classical hydrodynamics, the hydrodynamic impact problem is characterized as a boundary problem with moving boundary which position must be determined simultaneously with the solution of the field equation. This feature brings difficulties to get analytical and numerical solutions. In this sense, the purpose of this work is to present a variational method technique specifically designed for the hydrodynamic impact problem of axisymmetric rigid bodies on the free surface. The solution of the nonlinear dynamic equation of the impacting motion depends on the determination of the added mass tensor and its derivative with respect to time at each integration time step. This is done through a variational method…
Advisors/Committee Members: Pesce, Celso Pupo.
Subjects/Keywords: Abordagem GvKM; Desingularized techniques; GvKM approach; Hydrodynamic impact problem; Impacto vertical de corpos axissimétricos; Método numérico variacional; Problema de impacto hidrodinâmico; Técnicas dessingularizadas; Variational numerical method; Vertical impact of axisymmetric bodies
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APA (6th Edition):
Santos, F. M. d. (2013). Impacto hidrodinâmico vertical de corpos axissimétricos através de uma abordagem variacional. (Doctoral Dissertation). University of São Paulo. Retrieved from http://www.teses.usp.br/teses/disponiveis/3/3152/tde-22092014-110644/ ;
Chicago Manual of Style (16th Edition):
Santos, Flávia Milo dos. “Impacto hidrodinâmico vertical de corpos axissimétricos através de uma abordagem variacional.” 2013. Doctoral Dissertation, University of São Paulo. Accessed March 07, 2021.
http://www.teses.usp.br/teses/disponiveis/3/3152/tde-22092014-110644/ ;.
MLA Handbook (7th Edition):
Santos, Flávia Milo dos. “Impacto hidrodinâmico vertical de corpos axissimétricos através de uma abordagem variacional.” 2013. Web. 07 Mar 2021.
Vancouver:
Santos FMd. Impacto hidrodinâmico vertical de corpos axissimétricos através de uma abordagem variacional. [Internet] [Doctoral dissertation]. University of São Paulo; 2013. [cited 2021 Mar 07].
Available from: http://www.teses.usp.br/teses/disponiveis/3/3152/tde-22092014-110644/ ;.
Council of Science Editors:
Santos FMd. Impacto hidrodinâmico vertical de corpos axissimétricos através de uma abordagem variacional. [Doctoral Dissertation]. University of São Paulo; 2013. Available from: http://www.teses.usp.br/teses/disponiveis/3/3152/tde-22092014-110644/ ;

McMaster University
23.
Curry, Paul Douglas.
A Study of Deformed Light Nuclei USing The Sprung-Banerjee Interaction.
Degree: MSc, 1973, McMaster University
URL: http://hdl.handle.net/11375/17567
► The light even-even nuclei have been studied using the den~ity dependent effective interaction of Sprung and Banerjeee The nuclei were studied initially, using a…
(more)
▼ The light even-even nuclei have been studied using the den~ity dependent effective interaction of Sprung and Banerjeee The nuclei were studied initially, using a harmonic variational procedure, to deter mine the most appropriate parameters of t he force for the Hartree Fock study. This chosen force was then used in a comparative study of spherical nuclei to d e termine the inadequacies of our Hartn~e Fock approach, as opposed to the spherical basis calculations of Campi. Some deformed nuclei were then examined and our results were compared with those of K. Lassey and A. B. Volkov , and of J. Zofka and G. Ripka.
Thesis
Master of Science (MSc)
Advisors/Committee Members: Sprung, D.W.L., Physics.
Subjects/Keywords: nuclei; density dependent effective inraction; sprung; Banerjee; harmonic variational procedure; Hartree Fock approach; Campi calculations; nucleon-nucleon force; nuclear shell model
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APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
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APA (6th Edition):
Curry, P. D. (1973). A Study of Deformed Light Nuclei USing The Sprung-Banerjee Interaction. (Masters Thesis). McMaster University. Retrieved from http://hdl.handle.net/11375/17567
Chicago Manual of Style (16th Edition):
Curry, Paul Douglas. “A Study of Deformed Light Nuclei USing The Sprung-Banerjee Interaction.” 1973. Masters Thesis, McMaster University. Accessed March 07, 2021.
http://hdl.handle.net/11375/17567.
MLA Handbook (7th Edition):
Curry, Paul Douglas. “A Study of Deformed Light Nuclei USing The Sprung-Banerjee Interaction.” 1973. Web. 07 Mar 2021.
Vancouver:
Curry PD. A Study of Deformed Light Nuclei USing The Sprung-Banerjee Interaction. [Internet] [Masters thesis]. McMaster University; 1973. [cited 2021 Mar 07].
Available from: http://hdl.handle.net/11375/17567.
Council of Science Editors:
Curry PD. A Study of Deformed Light Nuclei USing The Sprung-Banerjee Interaction. [Masters Thesis]. McMaster University; 1973. Available from: http://hdl.handle.net/11375/17567

Université de Lorraine
24.
Ali, Sharib.
Total variational optical flow for robust and accurate bladder image mosaicing : Calcul du flot optique dans une approche variationnelle totale pour le mosaïquage robuste et précis d’images de la vessie.
Degree: Docteur es, Automatique, Traitement du Signal et des Images, Génie Informatique, 2016, Université de Lorraine
URL: http://www.theses.fr/2016LORR0006
► La cystoscopie est l’examen de référence pour le diagnostic et le traitement du cancer de la vessie. Le champ de vue (CdV) réduit des endoscopes…
(more)
▼ La cystoscopie est l’examen de référence pour le diagnostic et le traitement du cancer de la vessie. Le champ de vue (CdV) réduit des endoscopes complique le diagnostic et le suivi des lésions. Les mosaïques d’images sont une solution à ce problème car elles visualisent des CdV étendus. Toutefois, pour la vessie, le mosaïque d’images est un véritable défi à cause du faible contraste dans les images, des textures peu prononcées, de la variabilité intra- et inter-patient et des changements d’illumination dans les séquences. Ce défi est également à relever dans d’autres modalités endoscopiques ou dans des scènes non médicales comme les vidéos sous-marines. Dans cette thèse, une énergie variationnelle totale a d’abord été minimisée à l’aide d’un algorithme primal-dual du premier ordre pour obtenir un flot optique fournissant une correspondance dense et précise entre les points homologues des paires d’images. Les correspondances sont ensuite utilisées pour déterminer les paramètres des transformations requises pour le placement des images dans le repère global de la mosaïque. Les méthodes proposées pour l’estimation du flot optique dense incluent un terme d’attache aux données qui minimise le nombre des vecteurs aberrants et un terme de régularisation conçu pour préserver les discontinuités du champ devecteurs. Un algorithme de flot optique qui est robuste vis-à-vis de changements d’illumination importants (et utilisable pour différentes modalités) a également été développé dans ce contexte. La précision et la robustesse des méthodes de recalage proposées ont été testées sur des jeux de données (de flot optique) publiquement accessibles et sur des fantômes de vessies et de la peau. Des résultats sur des données patients acquises avec des cystoscopes rigides et flexibles, en lumière blanche ou en fluorescence, montrent la robustesse des algorithmes proposés. Ces résultats sont complétés par ceux obtenus pour d’autres séquences endoscopiques réelles de dermatoscopie, de scène sous-marine et de données d’exploration spatiale.
Cystoscopy is the reference procedure for the diagnosis and treatment of bladder cancer. The small field of view (FOV) of endoscopes makes both the diagnosis and follow-up of lesions difficult. Image mosaics are a solution to this problem since they visualize large FOVs of the bladder scene. However, due to low contrast, weak texture, inter- and intra-patient texture variability and illumination changes in these image sequences, the task of image mosaicing becomes challenging. This is also a major concern in other endoscopic data and non-medical scenes like underwater videos. In this thesis, a total variational energy has been first minimized using a first-order primal-dual algorithm in convex optimization to obtain optical flow vector fields giving a dense and accurate correspondence between homologous points of the image pairs. The correspondences are then used to obtain transformation parameters for registering the images to one global mosaic coordinate system. The proposed methods for dense…
Advisors/Committee Members: Daul, Christian (thesis director), Blondel, Walter (thesis director).
Subjects/Keywords: Approches variationnelles totales; Flot optique; Constance de structure; Descripteurs de voisinages; Régularisation anisotropique; Mosaïquage d'images endoscopiques; Total variational approach; Optical flow; Structure constancy; Neighbordood descriptors; Anistropic regularization; Convex optimization; Endoscopic image mosaicing; 621.367; 006.6
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Ali, S. (2016). Total variational optical flow for robust and accurate bladder image mosaicing : Calcul du flot optique dans une approche variationnelle totale pour le mosaïquage robuste et précis d’images de la vessie. (Doctoral Dissertation). Université de Lorraine. Retrieved from http://www.theses.fr/2016LORR0006
Chicago Manual of Style (16th Edition):
Ali, Sharib. “Total variational optical flow for robust and accurate bladder image mosaicing : Calcul du flot optique dans une approche variationnelle totale pour le mosaïquage robuste et précis d’images de la vessie.” 2016. Doctoral Dissertation, Université de Lorraine. Accessed March 07, 2021.
http://www.theses.fr/2016LORR0006.
MLA Handbook (7th Edition):
Ali, Sharib. “Total variational optical flow for robust and accurate bladder image mosaicing : Calcul du flot optique dans une approche variationnelle totale pour le mosaïquage robuste et précis d’images de la vessie.” 2016. Web. 07 Mar 2021.
Vancouver:
Ali S. Total variational optical flow for robust and accurate bladder image mosaicing : Calcul du flot optique dans une approche variationnelle totale pour le mosaïquage robuste et précis d’images de la vessie. [Internet] [Doctoral dissertation]. Université de Lorraine; 2016. [cited 2021 Mar 07].
Available from: http://www.theses.fr/2016LORR0006.
Council of Science Editors:
Ali S. Total variational optical flow for robust and accurate bladder image mosaicing : Calcul du flot optique dans une approche variationnelle totale pour le mosaïquage robuste et précis d’images de la vessie. [Doctoral Dissertation]. Université de Lorraine; 2016. Available from: http://www.theses.fr/2016LORR0006

Université Paris-Sud – Paris XI
25.
Zheng, Yuling.
Algorithmes bayésiens variationnels accélérés et applications aux problèmes inverses de grande taille : Fast variational Bayesian algorithms and their application to large dimensional inverse problems.
Degree: Docteur es, Physique, 2014, Université Paris-Sud – Paris XI
URL: http://www.theses.fr/2014PA112354
► Dans le cadre de cette thèse, notre préoccupation principale est de développer des approches non supervisées permettant de résoudre des problèmes de grande taille le…
(more)
▼ Dans le cadre de cette thèse, notre préoccupation principale est de développer des approches non supervisées permettant de résoudre des problèmes de grande taille le plus efficacement possible. Pour ce faire, nous avons considéré des approches bayésiennes qui permettent d'estimer conjointement les paramètres de la méthode avec l'objet d'intérêt. Dans ce cadre, la difficulté principale est que la loi a posteriori est en général complexe. Pour résoudre ce problème, nous nous sommes intéressés à l'approximation bayésienne variationnelle (BV) qui offre une approximation séparable de la loi a posteriori. Néanmoins, les méthodes d’approximation BV classiques souffrent d’une vitesse de convergence faible. La première contribution de cette thèse consiste à transposer les méthodes d'optimisation par sous-espace dans l'espace fonctionnel impliqué dans le cadre BV, ce qui nous permet de proposer une nouvelle méthode d'approximation BV. Nous avons montré l’efficacité de notre nouvelle méthode par les comparaisons avec les approches de l’état de l’art.Nous avons voulu ensuite confronter notre nouvelle méthodologie à des problèmes de traitement d'images de grande taille. De plus nous avons voulu favoriser les images régulières par morceau. Nous avons donc considéré un a priori de Variation Total (TV) et un autre a priori à variables cachées ressemblant à un mélange scalaire de gaussiennes par changement de positions. Avec ces deux modèles a priori, en appliquant notre méthode d’approximation BV, nous avons développé deux approches non-supervisées rapides et bien adaptées aux images régulières par morceau.En effet, les deux lois a priori introduites précédemment sont corrélées ce qui rend l'estimation des paramètres de méthode très compliquée : nous sommes souvent confronté à une fonction de partition non explicite. Pour contourner ce problème, nous avons considéré ensuite de travailler dans le domaine des ondelettes. Comme les coefficients d'ondelettes des images naturelles sont généralement parcimonieux, nous avons considéré des lois de la famille de mélange scalaire de gaussiennes par changement d'échelle (GSM) pour décrire la parcimonie. Une autre contribution est donc de développer une approche non-supervisée pour les lois de la famille GSM dont la densité est explicitement connue, en utilisant la méthode d'approximation BV proposée.
In this thesis, our main objective is to develop efficient unsupervised approaches for large dimensional problems. To do this, we consider Bayesian approaches, which allow us to jointly estimate regularization parameters and the object of interest. In this context, the main difficulty is that the posterior distribution is generally complex. To tackle this problem, we consider variational Bayesian (VB) approximation, which provides a separable approximation of the posterior distribution. Nevertheless, classical VB methods suffer from slow convergence speed. The first contribution of this thesis is to transpose the subspace optimization methods to the functional space involved in VB framework,…
Advisors/Committee Members: Rodet, Thomas (thesis director), Fraysse, Aurélia (thesis director).
Subjects/Keywords: Approximation bayésienne variationnelle; Optimisation par sous-espace; Problème de grande dimension; Approche non-supervisée; Parcimonie; Régularité par morceau; Variation totale; GSM; Variational Bayesian approximation; Subspace optimization; Large dimensional problem; Unsupervised approach; Sparsity; Piecewise smooth; Total variation; GSM
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Zheng, Y. (2014). Algorithmes bayésiens variationnels accélérés et applications aux problèmes inverses de grande taille : Fast variational Bayesian algorithms and their application to large dimensional inverse problems. (Doctoral Dissertation). Université Paris-Sud – Paris XI. Retrieved from http://www.theses.fr/2014PA112354
Chicago Manual of Style (16th Edition):
Zheng, Yuling. “Algorithmes bayésiens variationnels accélérés et applications aux problèmes inverses de grande taille : Fast variational Bayesian algorithms and their application to large dimensional inverse problems.” 2014. Doctoral Dissertation, Université Paris-Sud – Paris XI. Accessed March 07, 2021.
http://www.theses.fr/2014PA112354.
MLA Handbook (7th Edition):
Zheng, Yuling. “Algorithmes bayésiens variationnels accélérés et applications aux problèmes inverses de grande taille : Fast variational Bayesian algorithms and their application to large dimensional inverse problems.” 2014. Web. 07 Mar 2021.
Vancouver:
Zheng Y. Algorithmes bayésiens variationnels accélérés et applications aux problèmes inverses de grande taille : Fast variational Bayesian algorithms and their application to large dimensional inverse problems. [Internet] [Doctoral dissertation]. Université Paris-Sud – Paris XI; 2014. [cited 2021 Mar 07].
Available from: http://www.theses.fr/2014PA112354.
Council of Science Editors:
Zheng Y. Algorithmes bayésiens variationnels accélérés et applications aux problèmes inverses de grande taille : Fast variational Bayesian algorithms and their application to large dimensional inverse problems. [Doctoral Dissertation]. Université Paris-Sud – Paris XI; 2014. Available from: http://www.theses.fr/2014PA112354

Penn State University
26.
Wang, Xiaoqiang.
PHASE FIELD MODELS AND SIMULATIONS OF VESICLE BIO-MEMBRANES.
Degree: 2008, Penn State University
URL: https://submit-etda.libraries.psu.edu/catalog/6698
► Recently, we begin to systematically study the shape deformation of vesicle membranes by numerical simulations, sometimes under external fluid fields, using a unified energetic variational…
(more)
▼ Recently, we begin to systematically study the shape deformation of vesicle membranes
by numerical simulations, sometimes under external fluid fields, using a unified
energetic
variational formulation with phase field methods based on the minimization of
elastic bending energy with volume and surface area constraints ([21, 19, 20, 22, 23, 24]).
Analysis and numerical methods in both static and dynamic are developed to solve the
phase field models.
Phase field
approach is a global method, allowing topological changes of the interface.
And complex interfaces may be described as a relatively simple phase function
within the phase field
approach. Compare to other numerical methods, phase field
method is more unified, global, and relatively easier for implementation.
First we build the phase field theory for finding the equilibrium vesicle shapes.
Theoretically, we build the phase field model for the biological elastic bending energy
model. And the consistency of our phase field model with the general sharp interface
model is verified. Further, we develop a serial methods including the Euler-Lagrange
and penalty constraints methods to solving the phase field model. In guiding the numerical
simulations, we prove the convergence of our numerical simulation results to the
analytical phase field energy minimizers.
Many simulations are carried out to find the equilibrium shapes of vesicle membranes
in the axial symmetrical and the truly 3D cases. Different energetic bifurcation
phenomena are discussed. We also plot a relatively complete energy diagram. The effect
of the spontaneous curvature is also discussed for both constant and variable cases. In
the 3D non-symmetrical case, some non-symmetrical examples are found and compared
with biological experiments.
The study of the vesicle transformations within fluid fields is another important
contribution of this work. We successfully couple the phase field transformation with the
fluid dynamics. Theoretically analysis of the extra stress term caused by the membrane
to the fluids is carried out and further compared with the Euler-Lagrangian equation of
Willmore¡¯s problem. Energy laws within the coupled systems ensure the similar asymptotic
limit of the phase field formulation to the equilibrium system. Extensive three
dimensional numerical simulations are carried out guiding by a set of numerical schemes
for both the phase field transformation and fluid dynamics.
The last contribution of this work is that a series of new formulae is used in
detecting the topological changes in vesicle membrane transformations. More important,
some of the formulae are developed in a very general frame work and can be applied
to other problems and potentially can be used in controlling the structure of vesicle
membranes. Numerical simulations are carried out to check those formulae in all kinds
of cases involving the topological events.
For biology, this work gives the mathematical simulation to study the physics of
vesicle membranes. For mathematics, this work verifies the power of phase field…
Advisors/Committee Members: Qiang Du, Committee Chair/Co-Chair, Chun Liu, Committee Member, Ludmil Tomov Zikatanov, Committee Member, Hongyuan Zha, Committee Member.
Subjects/Keywords: Vesicle membrane; elastic bending energy; energetic variational approach; diffusive interface approximation; phase field model; numerical methods; three dimensional simulation; Navier-Stokes equation
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Wang, X. (2008). PHASE FIELD MODELS AND SIMULATIONS OF VESICLE BIO-MEMBRANES. (Thesis). Penn State University. Retrieved from https://submit-etda.libraries.psu.edu/catalog/6698
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Wang, Xiaoqiang. “PHASE FIELD MODELS AND SIMULATIONS OF VESICLE BIO-MEMBRANES.” 2008. Thesis, Penn State University. Accessed March 07, 2021.
https://submit-etda.libraries.psu.edu/catalog/6698.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Wang, Xiaoqiang. “PHASE FIELD MODELS AND SIMULATIONS OF VESICLE BIO-MEMBRANES.” 2008. Web. 07 Mar 2021.
Vancouver:
Wang X. PHASE FIELD MODELS AND SIMULATIONS OF VESICLE BIO-MEMBRANES. [Internet] [Thesis]. Penn State University; 2008. [cited 2021 Mar 07].
Available from: https://submit-etda.libraries.psu.edu/catalog/6698.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Wang X. PHASE FIELD MODELS AND SIMULATIONS OF VESICLE BIO-MEMBRANES. [Thesis]. Penn State University; 2008. Available from: https://submit-etda.libraries.psu.edu/catalog/6698
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
27.
Oubanas, Hind.
Variational assimilation of satellite data into a full Saint-Venant based hydraulic model in the context of ungauged basins : Assimilation variationnelle de données satellitaires dans un modèle hydraulique Saint-Venant complet dans le contexte de bassins non instrumentés.
Degree: Docteur es, Surfaces et interfaces continentales, Hydrologie, 2018, Université Toulouse III – Paul Sabatier
URL: http://www.theses.fr/2018TOU30102
► Ce sujet de thèse s'inscrit dans le cadre général de la mission satellitaire Surface Water and Ocean Topography (SWOT) et a pour objectif d'évaluer l'apport…
(more)
▼ Ce sujet de thèse s'inscrit dans le cadre général de la mission satellitaire Surface Water and Ocean Topography (SWOT) et a pour objectif d'évaluer l'apport de l'assimilation de données (AD) variationnelle en utilisant un modèle hydraulique 1.5D basé sur le système d'équations Saint-Venant complet. De plus, la méthode proposée est conçue pour une application dans le contexte général de bassins non instrumentés. Une première analyse de sensibilité avec la méthode de l'adjoint a été effectuée pour évaluer l'influence locale des variables et paramètres d'entrée du modèle sur ses sorties. La réponse du modèle est définie à partir d'une fonction objective des variables d'état. Celle-ci s'avère significativement sensible à la condition limite en débit amont, ainsi qu'aux variables de géomorphologie fluviale; le niveau du lit du fleuve et ses coefficients de frottements. Les sensibilités calculées renseignent sur les sections de contrôle qui ont une influence majeure sur l'hydraulique du fleuve et qui requièrent des relevés ou un calage plus précis. L'estimation du débit des fleuves à partir de données SWOT, a été ensuite étudiée, en utilisant une variante de la méthode conventionnelle '4D-Var'. Celle-ci permet d'estimer simultanément le débit, ainsi que la bathymétrie et les frottements dans le contexte de bassins non instrumentés, observés uniquement depuis l'espace. Deux configurations ont été analysées: (i) les expériences jumelles dans le cadre du fleuve Garonne, puis un cadre plus représentatif des données SWOT, en utilisant (ii) le simulateur SWOT d'hydrologie, sur les fleuves Po et Sacramento. En assimilant des données de hauteur d'eau, la bathymétrie et les frottements sont corrigés localement, permettant une meilleure estimation du débit. Toutefois, les variables estimées (bathymétrie et frottements) sont sujettes au problème d'équifinalité, et ne peuvent être exploitées pour des applications ultérieures. De plus, les résultats obtenus renseignent sur la fréquence temporelle des observations permettant une bonne estimation du débit et qui se doit d'être au moins équivalente au temps caractéristique du fleuve étudié. Pour finir, une nouvelle approche pour le traitement de l'erreur modèle en utilisant l'AD variationnelle a été proposée. Elle implique un traitement implicite basé sur une matrice de covariance des erreurs d'observations modifiée. Le théorème proposé est démontré et illustré par une application à l'équation 1D de Burger généralisée, ainsi qu'au cadre hydraulique en utilisant le modèle 1.5D saint-Venant complet.
The present thesis investigates the potential of variational data assimilation (DA) in discharge estimation from the future Surface Water and Ocean Topography (SWOT) satellite mission, using a 1.5D full Saint-Venant hydraulic model in the context of fully ungauged basins. Two distinct approaches for treating the model error are being investigated; the extended control vector approach, and a novel approach based on a modified covariance matrix. Adjoint sensitivity analysis was first performed…
Advisors/Committee Members: Malaterre, Pierre-Olivier (thesis director), Gejadze, Igor (thesis director), Mercier, Franck (thesis director).
Subjects/Keywords: Assimilation de données; Approche variationnelle; Incertitude; Analyse de sensibilité; Erreur modèle; Hydraulique fluviale; Équations Saint-Venant; Équation de Burger; Modélisation; Télédétection spatiale; Données satellitaires; Basins non instrumentés; SWOT; Data assimilation; Variational approach; Uncertainty; Sensitivity; Model error; River hydraulics; Saint-Venant equations; Burger’s equation; Modeling; Remote sensing; Satellite data; Ungauged basins; SWOT
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APA (6th Edition):
Oubanas, H. (2018). Variational assimilation of satellite data into a full Saint-Venant based hydraulic model in the context of ungauged basins : Assimilation variationnelle de données satellitaires dans un modèle hydraulique Saint-Venant complet dans le contexte de bassins non instrumentés. (Doctoral Dissertation). Université Toulouse III – Paul Sabatier. Retrieved from http://www.theses.fr/2018TOU30102
Chicago Manual of Style (16th Edition):
Oubanas, Hind. “Variational assimilation of satellite data into a full Saint-Venant based hydraulic model in the context of ungauged basins : Assimilation variationnelle de données satellitaires dans un modèle hydraulique Saint-Venant complet dans le contexte de bassins non instrumentés.” 2018. Doctoral Dissertation, Université Toulouse III – Paul Sabatier. Accessed March 07, 2021.
http://www.theses.fr/2018TOU30102.
MLA Handbook (7th Edition):
Oubanas, Hind. “Variational assimilation of satellite data into a full Saint-Venant based hydraulic model in the context of ungauged basins : Assimilation variationnelle de données satellitaires dans un modèle hydraulique Saint-Venant complet dans le contexte de bassins non instrumentés.” 2018. Web. 07 Mar 2021.
Vancouver:
Oubanas H. Variational assimilation of satellite data into a full Saint-Venant based hydraulic model in the context of ungauged basins : Assimilation variationnelle de données satellitaires dans un modèle hydraulique Saint-Venant complet dans le contexte de bassins non instrumentés. [Internet] [Doctoral dissertation]. Université Toulouse III – Paul Sabatier; 2018. [cited 2021 Mar 07].
Available from: http://www.theses.fr/2018TOU30102.
Council of Science Editors:
Oubanas H. Variational assimilation of satellite data into a full Saint-Venant based hydraulic model in the context of ungauged basins : Assimilation variationnelle de données satellitaires dans un modèle hydraulique Saint-Venant complet dans le contexte de bassins non instrumentés. [Doctoral Dissertation]. Université Toulouse III – Paul Sabatier; 2018. Available from: http://www.theses.fr/2018TOU30102
28.
Tanne, Erwan.
Variational phase-field models from brittle to ductile fracture : nucleation and propagation : Modèles variationnels à champ de phase pour la rupture de type fragile et ductile : nucléation et propagation.
Degree: Docteur es, Mécanique des matériaux, 2017, Université Paris-Saclay (ComUE)
URL: http://www.theses.fr/2017SACLX088
► Les simulations numériques des fissures fragiles par les modèles d’endommagement à gradient deviennent main- tenant très répandues. Les résultats théoriques et numériques montrent que dans…
(more)
▼ Les simulations numériques des fissures fragiles par les modèles d’endommagement à gradient deviennent main- tenant très répandues. Les résultats théoriques et numériques montrent que dans le cadre de l’existence d’une pre-fissure la propagation suit le critère de Griffith. Alors que pour le problème à une dimension la nucléation de la fissure se fait à la contrainte critique, cette dernière propriété dimensionne le paramètre de longueur interne.Dans ce travail, on s’attarde sur le phénomène de nucléation de fissures pour les géométries communément rencontrées et qui ne présentent pas de solutions analytiques. On montre que pour une entaille en U- et V- l’initiation de la fissure varie continument entre la solution prédite par la contrainte critique et celle par la ténacité du matériau. Une série de vérifications et de validations sur diffèrent matériaux est réalisée pour les deux géométries considérées. On s’intéresse ensuite à un défaut elliptique dans un domaine infini ou très élancé pour illustrer la capacité du modèle à prendre en compte les effets d’échelles des matériaux et des structures.Dans un deuxième temps, ce modèle est étendu à la fracturation hydraulique. Une première phase de vérification du modèle est effectuée en stimulant une pré-fissure seule par l’injection d’une quantité donnée de fluide. Ensuite on étudie la simulation d’un réseau parallèle de fissures. Les résultats obtenus montrent qu’il a qu’une seule fissure qui se propage et que ce type de configuration minimise mieux l’énergie la propagation d’un réseau de fractures. Le dernier exemple se concentre sur la stabilité des fissures dans le cadre d’une expérience d’éclatement à pression imposée pour l’industrie pétrolière. Cette expérience d’éclatement de la roche est réalisée en laboratoire afin de simuler les conditions de confinement retrouvées lors des forages.La dernière partie de ce travail se concentre sur la rupture ductile en couplant le modèle à champ de phase avec les modèles de plasticité parfaite. Grâce à l’approche variationnelle du problème on décrit l’implantation numérique retenue pour le calcul parallèle. Les simulations réalisées montrent que pour une géométrie légèrement entaillée la phénoménologie des fissures ductiles comme par exemple la nucléation et la propagation sont en concordances avec ceux reportées dans la littérature.
Phase-field models, sometimes referred to as gradient damage, are widely used methods for the numerical simulation of crack propagation in brittle materials. Theoretical results and numerical evidences show that they can predict the propagation of a pre-existing crack according to Griffith’s criterion. For a one- dimensional problem, it has been shown that they can predict nucleation upon a critical stress, provided that the regularization parameter is identified with the material’s internal characteristic length.In this work, we draw on numerical simulations to study crack nucleation in commonly encountered geometries for which closed-form solutions are not available. We use U- and V-notches to…
Advisors/Committee Members: Marigo, Jean-Jacques (thesis director), Bourdin, Blaise (thesis director).
Subjects/Keywords: Modèles à champ de phase pour la rupture; Nucléation de fissure; Effet d’échelle dans les matériaux fragiles; Modèles d’endommagement à gradient; Fracturation hydraulique; Stabilité des fissures; Modèles de plasticités; Approche variationnelle; Rupture ductile; Phase-field models of fracture; Crack nucleation; Size effects in brittle materials; Gradient damage models; Hydraulic fracturing; Crack stability; Plasticity model; Variational approach; Ductile fracture; 620.112 6
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Tanne, E. (2017). Variational phase-field models from brittle to ductile fracture : nucleation and propagation : Modèles variationnels à champ de phase pour la rupture de type fragile et ductile : nucléation et propagation. (Doctoral Dissertation). Université Paris-Saclay (ComUE). Retrieved from http://www.theses.fr/2017SACLX088
Chicago Manual of Style (16th Edition):
Tanne, Erwan. “Variational phase-field models from brittle to ductile fracture : nucleation and propagation : Modèles variationnels à champ de phase pour la rupture de type fragile et ductile : nucléation et propagation.” 2017. Doctoral Dissertation, Université Paris-Saclay (ComUE). Accessed March 07, 2021.
http://www.theses.fr/2017SACLX088.
MLA Handbook (7th Edition):
Tanne, Erwan. “Variational phase-field models from brittle to ductile fracture : nucleation and propagation : Modèles variationnels à champ de phase pour la rupture de type fragile et ductile : nucléation et propagation.” 2017. Web. 07 Mar 2021.
Vancouver:
Tanne E. Variational phase-field models from brittle to ductile fracture : nucleation and propagation : Modèles variationnels à champ de phase pour la rupture de type fragile et ductile : nucléation et propagation. [Internet] [Doctoral dissertation]. Université Paris-Saclay (ComUE); 2017. [cited 2021 Mar 07].
Available from: http://www.theses.fr/2017SACLX088.
Council of Science Editors:
Tanne E. Variational phase-field models from brittle to ductile fracture : nucleation and propagation : Modèles variationnels à champ de phase pour la rupture de type fragile et ductile : nucléation et propagation. [Doctoral Dissertation]. Université Paris-Saclay (ComUE); 2017. Available from: http://www.theses.fr/2017SACLX088
29.
Bashtova, Kateryna.
Modélisation et identification de paramètres pour les empreintes des faisceaux de haute énergie. : Modelling and parameter identification for energy beam footprints.
Degree: Docteur es, Mathématiques, 2016, Université Côte d'Azur (ComUE)
URL: http://www.theses.fr/2016AZUR4112
► Le progrès technologique nécessite des techniques de plus en plus sophistiquées et précises de traitement de matériaux. Nous étudions le traitement de matériaux par faisceaux…
(more)
▼ Le progrès technologique nécessite des techniques de plus en plus sophistiquées et précises de traitement de matériaux. Nous étudions le traitement de matériaux par faisceaux de haute énergie : un jet d’eau abrasif, une sonde ionique focalisée, un laser. L’évolution de la surface du matériau sous l’action du faisceau de haute énergie est modélisée par une EDP. Cette équation contient l’ensemble des coefficients inconnus - les paramètres de calibration de mo- dèle. Les paramètres inconnus peuvent être calibrés par minimisation de la fonction coût, c’est-à-dire, la fonction qui décrit la différence entre le résultat de la modélisation et les données expérimentales. Comme la surface modélisée est une solution du problème d’EDP, cela rentre dans le cadre de l’optimisation sous contrainte d’EDP. L’identification a été rendue bien posée par la régularisation du type Tikhonov. Le gradient de la fonction coût a été obtenu en utilisant les deux méthodes : l’approche adjointe et la différen- ciation automatique. Une fois la fonction coût et son gradient obtenus, nous avons utilisé un minimiseur L-BFGS pour réaliser la minimisation.Le problème de la non-unicité de la solution a été résolu pour le problème de traitement par le jet d’eau abrasif. Des effets secondaires ne sont pas inclus dans le modèle. Leur impact sur le procédé de calibration a été évité. Ensuite, le procédé de calibration a été validé pour les données synthétiques et expérimentales. Enfin, nous avons proposé un critère pour distinguer facilement entre le régime thermique et non- thermique d’ablation par laser.
The technological progress demands more and more sophisticated and precise techniques of the treatment of materials. We study the machining of the material with the high energy beams: the abrasive waterjet, the focused ion beam and the laser. Although the physics governing the energy beam interaction with material is very different for different application, we can use the same approach to the mathematical modeling of these processes.The evolution of the material surface under the energy beam impact is modeled by PDE equation. This equation contains a set of unknown parameters - the calibration parameters of the model. The unknown parameters can be identified by minimization of the cost function, i.e., function that describes the differ- ence between the result of modeling and the corresponding experimental data. As the modeled surface is a solution of the PDE problem, this minimization is an example of PDE-constrained optimization problem. The identification problem was regularized using Tikhonov regularization. The gradient of the cost function was obtained both by using the variational approach and by means of the automatic differentiation. Once the cost function and its gradient calculated, the minimization was performed using L-BFGS minimizer.For the abrasive waterjet application the problem of non-uniqueness of numerical solution is solved. The impact of the secondary effects non included into the model is avoided as well. The calibration…
Advisors/Committee Members: Auroux, Didier (thesis director).
Subjects/Keywords: Optimisation sous contrainte d'EDP; Paramètres de calibration; Approche variationnelle; Problème adjoint; Différenciation automatique; TAPENADE; Régularisation du type Tikhonov; Courbe L; Jet d'eau abrasif; Sonde ionique focalisée; Laser; PDE constrained optimization; Parameters calibration; Variational approach; Continuous adjoint problem; Discrete adjoint problem; Automatic differentiation; TAPENADE A.D. engine; Tikhonov regularization; L-curve; Abrasive waterjet; Focused ion beam; Laser ablation
Record Details
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Record Details
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Bashtova, K. (2016). Modélisation et identification de paramètres pour les empreintes des faisceaux de haute énergie. : Modelling and parameter identification for energy beam footprints. (Doctoral Dissertation). Université Côte d'Azur (ComUE). Retrieved from http://www.theses.fr/2016AZUR4112
Chicago Manual of Style (16th Edition):
Bashtova, Kateryna. “Modélisation et identification de paramètres pour les empreintes des faisceaux de haute énergie. : Modelling and parameter identification for energy beam footprints.” 2016. Doctoral Dissertation, Université Côte d'Azur (ComUE). Accessed March 07, 2021.
http://www.theses.fr/2016AZUR4112.
MLA Handbook (7th Edition):
Bashtova, Kateryna. “Modélisation et identification de paramètres pour les empreintes des faisceaux de haute énergie. : Modelling and parameter identification for energy beam footprints.” 2016. Web. 07 Mar 2021.
Vancouver:
Bashtova K. Modélisation et identification de paramètres pour les empreintes des faisceaux de haute énergie. : Modelling and parameter identification for energy beam footprints. [Internet] [Doctoral dissertation]. Université Côte d'Azur (ComUE); 2016. [cited 2021 Mar 07].
Available from: http://www.theses.fr/2016AZUR4112.
Council of Science Editors:
Bashtova K. Modélisation et identification de paramètres pour les empreintes des faisceaux de haute énergie. : Modelling and parameter identification for energy beam footprints. [Doctoral Dissertation]. Université Côte d'Azur (ComUE); 2016. Available from: http://www.theses.fr/2016AZUR4112
30.
Nüske, Feliks.
Der Variationsansatz für Konformationsdynamik.
Degree: 2017, Freie Universität Berlin
URL: http://dx.doi.org/10.17169/refubium-11386
► Die vorliegende Arbeit beschreibt eine Methode, genannt variational approach to conformational dynamics (VAC), zur Analyse von Simulationsdaten von hochdimensionalen stochastischen Prozessen. Dabei liegt der Fokus…
(more)
▼ Die vorliegende Arbeit beschreibt eine Methode, genannt
variational approach
to conformational dynamics (VAC), zur Analyse von Simulationsdaten von
hochdimensionalen stochastischen Prozessen. Dabei liegt der Fokus auf
reversiblen Markov-Prozessen und auf der Anwendung im Bereich von
Molekulardynamik Simulationen. Die grundlegende Idee ist es, die führenden
Eigenfunktionen des mit dem Markov-Prozess assoziierten Transferoperators aus
einer vorab gewählten Menge von Basisfunktionen zu approximieren. Die auf
diese Art approximierten Eigenfunktionen können zur niedrig-dimensionalen
Darstellung des Prozesses verwendet werden. Zur Bestimmung der Approximation
muss ein generalisiertes Eigenwertproblem gelöst werden, wobei die dafür
benötigten Matrizen aus langen Simulationen berechnet werden können. In der
Arbeit wurde die Verwendung von Tensorprodukt Darstellungen diskutiert, damit
die Methode mit einer möglichst großen und dennoch interpretierbaren Basis
verwendet werden kann. Um den dabei auftretenden “Fluch der Dimension” zu
vermeiden, wurde ein Niedrigrang-Format, das tensor-train-format, verwendet.
Die zugehörigen Algorithmen wurden an die Problemstellung angepasst und
erfolgreich auf Beispielsysteme angewandt. Im letzten Teil der Arbeit wurde
untersucht, wie die Methode auch mit Hilfe von vielen Kurzzeit-Simulationen
verwendet werden kann. Diese Frage wurde zunächst für Markov state models
(MSM) untersucht, die einen Spezialfall des VAC darstellen. Wir haben einen
Ausdruck für den Fehler bei der MSM Schätzung aus zu kurzen Simulationen
hergeleitet. Anschließend wurde erklärt, wie sich der Fehler mit Hilfe von
observable operator models (OOM) korrigieren lässt. Die Diskussion
algorithmischer Details und die Anwendung auf Beispielsysteme bilden den
Abschluss der Arbeit.
Advisors/Committee Members: m (gender), Prof. Dr. Frank Noé (firstReferee), Prof. Dr. Reinhold Schneider (furtherReferee).
Subjects/Keywords: Molecular Dynamics; Transfer Operator; Conformation Dynamics; Markov State Models; Variational Approach; Tensor Products; 500 Naturwissenschaften und Mathematik; 500 Naturwissenschaften und Mathematik::510 Mathematik; 500 Naturwissenschaften und Mathematik::510 Mathematik::519 Wahrscheinlichkeiten, angewandte Mathematik
…sets
Sm , see again Refs. [6, 8].
11
Chapter 3
The Variational Formulation
We… …chapter, we introduce a variational
formulation for the leading eigenvalues of the transfer… …3.1 The Variational Theorem
In order to approximate the dominant eigenfunctions ψm and… …standard Rayleigh principle for selfadjoint operators [48]
12
3.1. THE VARIATIONAL… …h f i , f j iµ .
(3.1.9)
13
3.1. THE VARIATIONAL THEOREM
Proof. First, note…
Record Details
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Record Details
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Nüske, F. (2017). Der Variationsansatz für Konformationsdynamik. (Thesis). Freie Universität Berlin. Retrieved from http://dx.doi.org/10.17169/refubium-11386
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Nüske, Feliks. “Der Variationsansatz für Konformationsdynamik.” 2017. Thesis, Freie Universität Berlin. Accessed March 07, 2021.
http://dx.doi.org/10.17169/refubium-11386.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Nüske, Feliks. “Der Variationsansatz für Konformationsdynamik.” 2017. Web. 07 Mar 2021.
Vancouver:
Nüske F. Der Variationsansatz für Konformationsdynamik. [Internet] [Thesis]. Freie Universität Berlin; 2017. [cited 2021 Mar 07].
Available from: http://dx.doi.org/10.17169/refubium-11386.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Nüske F. Der Variationsansatz für Konformationsdynamik. [Thesis]. Freie Universität Berlin; 2017. Available from: http://dx.doi.org/10.17169/refubium-11386
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
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