Teses / dissertações sobre o tema "Continuous or discrete homogenization"
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Rizzi, Gianluca. "Strain-gradient effects in the discrete/continuum transition via homogenization". Doctoral thesis, Università degli studi di Trento, 2019. https://hdl.handle.net/11572/369095.
Texto completo da fonteRizzi, Gianluca. "Strain-gradient effects in the discrete/continuum transition via homogenization". Doctoral thesis, University of Trento, 2019. http://eprints-phd.biblio.unitn.it/3552/1/Rizzi_Gianluca_PhD_thesis.pdf.
Texto completo da fonteLauerbach, Laura [Verfasser], Anja [Gutachter] Schlömerkemper e Martin [Gutachter] Kruzik. "Stochastic Homogenization in the Passage from Discrete to Continuous Systems - Fracture in Composite Materials / Laura Lauerbach ; Gutachter: Anja Schlömerkemper, Martin Kruzik". Würzburg : Universität Würzburg, 2020. http://d-nb.info/1220634239/34.
Texto completo da fonteRuf, Matthias [Verfasser], Marco [Akademischer Betreuer] [Gutachter] Cicalese, Antoine [Gutachter] Gloria e Andrea [Gutachter] Braides. "Discrete-to-continuum limits and stochastic homogenization of ferromagnetic surface energies / Matthias Ruf ; Gutachter: Antoine Gloria, Marco Cicalese, Andrea Braides ; Betreuer: Marco Cicalese". München : Universitätsbibliothek der TU München, 2017. http://d-nb.info/1137323493/34.
Texto completo da fonteAlavi, Seyed Ehsan. "Homogénéisation de milieux architecturés périodiques et quasi-périodiques vers des milieux continus généralisés". Electronic Thesis or Diss., Université de Lorraine, 2021. http://www.theses.fr/2021LORR0305.
Texto completo da fonteThis thesis aims to revisit higher-order homogenization schemes towards higher-order or higher gradient continua, successively for periodic and quasi-periodic architected materials and composites, based on variational principles and an extension of Hill macrohomogeneity condition. Continuous homogenization methods are exposed in Part I for micropolar and micromorphic media, followed by an exposition of the alternative discrete homogenization method.We have extended these theoretical developments to the situation of quasi-periodic materials, which still have a regular microstructure. The common idea to the proposed periodic homogenization methods of continuous or discrete nature is to split the microscopic displacement into a homogeneous part representative of the kinematics of the adopted effective continuum and a fluctuation evaluated from a variational principle. In substance, the theoretical developments allow the elaboration of enriched continua (generalized continua) of micromorphic type and all sub continua obtained using suitable degeneration conditions. Numerical applications have been made for architected materials and inclusion-based composites prone to higher-order effects due to their inner architecture. On the theoretical framework, the performed developments remedy many existing limitations of existing higher-order homogenization schemes.In Part II, repetitive lattice materials' effective classical and higher-order mechanical properties have been evaluated based on discrete homogenization schemes. Following the idea of a phenomenological approach, consistent couple stress models of repetitive beam lattices have been elaborated. Enriched Cosserat media have been derived in the spirit of micromechanics, adopting Timoshenko beam models at a microlevel, and applying a continualization method towards a Cosserat effective substitution medium. The proposed continualization method proves to be accurate and computationally efficient compared to continuous homogenization schemes and fully resolved finite element simulations. One key outcome of the performed analyses is the quantification of edge effects in the response of lattice structures, relying on the surface formulation of the extended Hill macrohomogeneity condition.The theoretical background underlying quasi-periodic asymptotic homogenization in the framework of linearized anisotropic elasticity deserves the development of Part III. Different methodologies for evaluating the effective quasi-periodic properties have been elaborated, leading to the emergence of strain gradient effective media. Conformal transformations define a specific class of geometrical mappings, allowing for designing compatible architected materials with inner porosity gradient, making them suitable bone biomechanics candidates
Baird, Graham. "Mixed discrete-continuous fragmentation equations". Thesis, University of Oxford, 2017. https://ora.ox.ac.uk/objects/uuid:311da0da-6801-4120-9129-d95786a153b6.
Texto completo da fonteSilva, Pedro André Arroyo. "Modelo matemático com parâmetros que dependem da discretização: aplicação ao estudo de fenômenos de propagação discreta em meios excitáveis". Universidade Federal de Juiz de Fora (UFJF), 2018. https://repositorio.ufjf.br/jspui/handle/ufjf/7194.
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A formação de padrões espaço-temporais são observados em processos químicos e bio-lógicos. Apesar dos sistemas bioquímicos serem altamente heterogêneos, aproximações homogenizadas contínuas formadas por equações diferenciais parciais são utilizadas fre-quentemente. Estas aproximações são usualmente justificadas pela diferença de escalas entre as heterogeneidades e o tamanho da característica espacial dos padrões. Em certas condições do meio, por exemplo, quando há um acoplamento fraco entre as células car-díacas, os modelos homogenizados discretos são mais adequados. Entretanto, os modelos discretos são menos manejáveis, por exemplo, na geração de malha para 2D e 3D, se comparado com os modelos contínuos. Aqui estudamos um modelo matemático homoge-nizado contínuo que se aproxima do modelo homogenizado. Este modelo é dado a partir de equações diferencias parciais com um parâmetro que depende da discretização da ma-lha. Dessa maneira nos referimos a este por um modelo matemático com parâmetros que dependem da discretização. Validamos nossa aproximação em um meio excitável genérico que simula três fenômenos em 1D: a propagação do potencial de ação transmembrânico no tecido cardíaco, a propagação do potencial de ação em filamentos de axônios cobertos por bainhas de mielina e a propagação do ativador e inibidor em microemulsões químicas. Para o caso 2D desenvolvemos uma versão da nossa aproximação que reproduz ondas espirais em um meio com acoplamento fraco.
The spatio-temporal patterns formations are observed in chemical and biological pro-cesses. Although biochemical systems are highly heterogeneous, homogenized continuum approaches formed by partial differential equations have been employed frequently. These approaches are usually justified by the difference scales between the characteristic spatial size of the patterns. Under some conditions of the medium, for instance, under weak coupling between cardiac cells, discrete models are more adequate. On the other hand discrete models may be less manageable, for instance, in terms of mesh generation, com-pared to the continuum models. Here we study a mathematical model to approach the discreteness which permits the computer implementation on non-uniform meshes. The model is cast as a partial differential equation but with a parameter that depends on the discretization mesh. Therefore we refer to it as a mathematical model with parameters dependent of discretization. We validate the approach in a generic excitable media that simulates three different phenomena in 1D: the propagation of action potential in car-diac tissue, the propation of the action potentialin filaments of axons wrapped by myelin sheaths, and the propagation of the activator/inhibitor in chemical microemulsions. For the 2D case we develop a version to this approach in microemulsions where it was possible to reproduce spiral waves with weak coupling of the medium.
ElNady, Khaled. "Modèles de comportement non linéaire des matériaux architecturés par des méthodes d'homogénéisation discrètes en grandes déformations. Application à des biomembranes et des textiles". Thesis, Université de Lorraine, 2015. http://www.theses.fr/2015LORR0032/document.
Texto completo da fonteThe present thesis deals with the development of micromechanical schemes for the computation of the homogenized response of architectured materials, focusing on periodical lattice materials. Architectured and micro-architectured materials cover a wide range of mechanical properties according to the nodal connectivity, geometrical arrangement of the structural elements, their moduli, and a possible structural hierarchy. The principal objective of the thesis is the consideration of geometrical nonlinearities accounting for the large changes of the initial lattice geometry, due to the small bending stiffness of the structural elements, in comparison to their tensile rigidity. The so-called discrete homogenization method is extended to the geometrically nonlinear setting for periodical lattices; incremental schemes are constructed based on a staggered localization-homogenization computation of the lattice response over a repetitive unit cell submitted to a controlled deformation loading. The obtained effective medium is a micropolar anisotropic continuum, the effective properties of which accounting for the geometrical arrangement of the structural elements within the lattice and their mechanical properties. The non affine response of the lattice leads to possible size effects which can be captured by an enrichment of the classical Cauchy continuum either by adding rotational degrees of freedom as for the micropolar effective continuum, or by considering second order gradients of the displacement field. Both strategies are followed in this work, the construction of second order grade continua by discrete homogenization being done in a small perturbations framework. We show that both strategies for the enrichment of the effective continuum are complementary due to the existing analogy in the construction of the micropolar and second order grade continua by homogenization. The combination of both schemes further delivers tension, bending and torsion internal lengths, which reflect the lattice topology and the mechanical properties of its structural elements. Applications to textiles and biological membranes described as quasi periodical networks of filaments are considered. The computed effective response is validated by comparison with FE simulations performed over a representative unit cell of the lattice. The homogenization schemes have been implemented in a dedicated code written in combined symbolic and numerical language, and using as an input the lattice geometry and microstructural mechanical properties. The developed predictive micromechanical schemes offer a design tool to conceive new architectured materials to expand the boundaries of the 'material-property' space
Schlömerkemper, Anja. "Magnetic forces in discrete and continuous systems". Doctoral thesis, Universitätsbibliothek Leipzig, 2004. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-37349.
Texto completo da fonteDas Thema dieser Arbeit ist eine mathematisch strenge Herleitung von Formeln für die magnetische Kraft, die auf einen Teil eines beschränkten, magnetischen Körpers durch seine Umgebung ausgeübt wird. Zunächst wird die magnetische Kraft in einem kontinuierlichen System auf Grundlage der makroskopischen Magnetostatik betrachtet. Mit Bezug auf W. F. Brown, der eine vor allem physikalisch motivierte Herleitung der Kraftformel gegeben hat, wird diese auch Brownsche Kraftformel genannt. Das Oberflächenintegral in dieser Formel zeigt eine nichtlineare Abhängigkeit von der Normalen. Um Cauchys Theorem aus der Kontinuumsmechanik in einem magnetoelastischen Material anwenden zu können, nimmt Brown an, dass die Oberflächenkraft einen zusäatzlichen Term enthält, der den nichtlinearen Ausdruck aufhebt. Der Beweis der Brownschen Kraftformel in dieser Arbeit beruht auf einer geeigneten Regularisierung eines hypersingulären Kerns und benutzt Methoden für singuläre Integrale. Danach gehen wir von einem diskreten, periodischen System von magnetischen Dipolen aus und betrachten die Kraft zwischen einem Teil einer beschränkten Menge und der Umgebung. Um zum Kontinuumslimes überzugehen, starten wir von der üblichen Kraftformel für wechselwirkende magnetische Dipole. Es zeigt sich, dass sich der Limes der diskreten Kraft von der Brownschen Kraftformel unterscheidet. Man erhält einen zusätzlichen nichtlinearen Oberflächenterm, der es ermöglicht, Browns Annahme als Konsequenz des atomistischen Zugangs zu sehen. Kurzreichweitige Effekte führen zudem zu einem linearen Oberflächenterm im Kontinuumlimes der diskreten Kraft. Dieser Zusatzterm enthält eine gewisse Gittersumme, die von einem hypersingulären Kern und der Struktur des zugrundeliegenden Gitters abhängt
Kimia, Behjoo. "Deblurring Gaussian blur : continuous and discrete approaches". Thesis, McGill University, 1986. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=65339.
Texto completo da fonteLee, Wai Ha. "Continuous and discrete properties of stochastic processes". Thesis, University of Nottingham, 2010. http://eprints.nottingham.ac.uk/11194/.
Texto completo da fonteSherman, Benjamin (Benjamin Marc). "Making discrete decisions based on continuous values". Thesis, Massachusetts Institute of Technology, 2017. http://hdl.handle.net/1721.1/112004.
Texto completo da fonteThis electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references (pages 99-102).
Many safety-critical software systems are cyber-physical systems that compute with continuous values; confirming their safety requires guaranteeing the accuracy of their computations. It is impossible for these systems to compute (total and deterministic) discrete computations (e.g., decisions) based on connected input spaces such as R. We propose a programming language based on constructive topology, whose types are spaces and programs are executable continuous maps, that facilitates making formal guarantees of accuracy of computed results. We demonstrate that discrete decisions can be made based on continuous values by permitting nondeterminism. This thesis describes variants of the programming language allowing nondeterminism and/or partiality, and introduces two tools for creating nondeterministic programs on spaces. Overlapping pattern matching is a generalization of pattern matching in functional programming, where patterns need not represent decidable predicates and also may overlap, allowing potentially nondeterministic behavior in overlapping regions. Binary covers, which are pairs of predicates such that at least one of them holds, yield a formal logic for constructing approximate decision procedures.
by Benjamin Sherman.
S.M.
Janiszewski, Szymon Pawel. "Optimization problems in discrete and continuous time". Thesis, University of Hull, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.396087.
Texto completo da fonteZhu, Qingxin Carleton University Dissertation Computer Science. "Optimal search in discrete and continuous spaces". Ottawa, 1996.
Encontre o texto completo da fonteHouben, Dirk. "Return Smoothing in Discrete and Continuous Time". Thesis, The University of Sydney, 2020. https://hdl.handle.net/2123/24564.
Texto completo da fonteWesthead, Martin D. "Continuous automata : bridging the gap between discrete and continuous time system models". Thesis, University of Edinburgh, 1998. http://hdl.handle.net/1842/27642.
Texto completo da fonteLiao, Tianjun. "Population-based heuristic algorithms for continuous and mixed discrete-continuous optimization problems". Doctoral thesis, Universite Libre de Bruxelles, 2013. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/209439.
Texto completo da fontehave a domain that typically is a subset of the real numbers; mixed discrete-continuous
optimization problems have additionally other types of variables, so
that some variables are continuous and others are on an ordinal or categorical
scale. Continuous and mixed discrete-continuous problems have a wide range
of applications in disciplines such as computer science, mechanical or electrical
engineering, economics and bioinformatics. These problems are also often hard to
solve due to their inherent difficulties such as a large number of variables, many
local optima or other factors making problems hard. Therefore, in this thesis our
focus is on the design, engineering and configuration of high-performing heuristic
optimization algorithms.
We tackle continuous and mixed discrete-continuous optimization problems
with two classes of population-based heuristic algorithms, ant colony optimization
(ACO) algorithms and evolution strategies. In a nutshell, the main contributions
of this thesis are that (i) we advance the design and engineering of ACO algorithms to algorithms that are competitive or superior to recent state-of-the-art
algorithms for continuous and mixed discrete-continuous optimization problems,
(ii) we improve upon a specific state-of-the-art evolution strategy, the covariance
matrix adaptation evolution strategy (CMA-ES), and (iii) we extend CMA-ES to
tackle mixed discrete-continuous optimization problems.
More in detail, we propose a unified ant colony optimization (ACO) framework
for continuous optimization (UACOR). This framework synthesizes algorithmic
components of two ACO algorithms that have been proposed in the literature
and an incremental ACO algorithm with local search for continuous optimization,
which we have proposed during my doctoral research. The design of UACOR
allows the usage of automatic algorithm configuration techniques to automatically
derive new, high-performing ACO algorithms for continuous optimization. We also
propose iCMAES-ILS, a hybrid algorithm that loosely couples IPOP-CMA-ES, a
CMA-ES variant that uses a restart schema coupled with an increasing population
size, and a new iterated local search (ILS) algorithm for continuous optimization.
The hybrid algorithm consists of an initial competition phase, in which IPOP-CMA-ES and the ILS algorithm compete for further deployment during a second
phase. A cooperative aspect of the hybrid algorithm is implemented in the form
of some limited information exchange from IPOP-CMA-ES to the ILS algorithm
during the initial phase. Experimental studies on recent benchmark functions
suites show that UACOR and iCMAES-ILS are competitive or superior to other
state-of-the-art algorithms.
To tackle mixed discrete-continuous optimization problems, we extend ACOMV
and propose CESMV, an ant colony optimization algorithm and a covariance matrix adaptation evolution strategy, respectively. In ACOMV and CESMV ,the decision variables of an optimization problem can be declared as continuous, ordinal, or categorical, which allows the algorithm to treat them adequately. ACOMV and
CESMV include three solution generation mechanisms: a continuous optimization
mechanism, a continuous relaxation mechanism for ordinal variables, and a categorical optimization mechanism for categorical variables. Together, these mechanisms allow ACOMV and CESMV to tackle mixed variable optimization problems.
We also propose a set of artificial, mixed-variable benchmark functions, which can
simulate discrete variables as ordered or categorical. We use them to automatically tune ACOMV and CESMV's parameters and benchmark their performance.
Finally we test ACOMV and CESMV on various real-world continuous and mixed-variable engineering optimization problems. Comparisons with results from the
literature demonstrate the effectiveness and robustness of ACOMV and CESMV
on mixed-variable optimization problems.
Apart from these main contributions, during my doctoral research I have accomplished a number of additional contributions, which concern (i) a note on the
bound constraints handling for the CEC'05 benchmark set, (ii) computational results for an automatically tuned IPOP-CMA-ES on the CEC'05 benchmark set and
(iii) a study of artificial bee colonies for continuous optimization. These additional
contributions are to be found in the appendix to this thesis.
Doctorat en Sciences de l'ingénieur
info:eu-repo/semantics/nonPublished
Maza, Sabido Susanna. "Discrete and continuous symetries in planar vector fields". Doctoral thesis, Universitat de Lleida, 2008. http://hdl.handle.net/10803/81314.
Texto completo da fonteMaza, Sabido Susana. "Discrete and continuous symetries in planar vector fields". Doctoral thesis, Universitat de Lleida, 2008. http://hdl.handle.net/10803/81314.
Texto completo da fonteDasci, Abdullah. "Discrete and continuous models for production-distribution systems". Thesis, McGill University, 2001. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=37625.
Texto completo da fonteThe models proposed in this thesis are based on two fundamentally different but equally central approaches. The first approach builds on traditionally popular integer programming formulation in facility location theory, in which two such models presented in this thesis. The first one assumes that there are a number of dedicated production technologies for each product whereas, the second one assumes that a set of flexible technologies is also present. Analytical properties of the models are described, which lead to the development of exact and heuristic solution procedures. Results of several sets of computational experiments are also reported. The second approach is based on continuous approximation (also known as continuum mechanics), which has not been used to its potential in the literature. The third model in this thesis is proposed for a system with single product. It is based on the use of continuous functions in representing spatial distribution of cost parameters and decision variables. In this model, the focus is to compute the service regions leaving the precise plant locations to a subsequent analysis. This model lends itself to closed form solutions and allows derivation of a number of insights on the impact of several cost factors on facility design decisions. Then, it is utilized in an analytical framework to analyze several plant focus decisions of firms in a multi-product environment. The closed form solution is used to analyze several product and market focus strategies, which have provided several insights into more sophisticated plant focus decisions and into the impact of different production technologies on these decisions.
Smith, Jason Marko. "Discrete properties of continuous, non-Gaussian random processes". Thesis, University of Nottingham, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.438330.
Texto completo da fonteWebster, Helen Nicola. "On the continuous and discrete third Painleve equations". Thesis, University of Kent, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.267390.
Texto completo da fonteParra, Rojas César. "Intrinsic fluctuations in discrete and continuous time models". Thesis, University of Manchester, 2017. https://www.research.manchester.ac.uk/portal/en/theses/intrinsic-fluctuations-in-discrete-and-continuous-time-models(d7006a2b-1496-44f2-8423-1f2fa72be1a5).html.
Texto completo da fonteVanel, Alice. "Asymptotic analysis of discrete and continuous periodic media". Thesis, Imperial College London, 2018. http://hdl.handle.net/10044/1/64911.
Texto completo da fonteSchimmer, Lukas Wolfgang. "Spectral inequalities for discrete and continuous differential operators". Thesis, Imperial College London, 2014. http://hdl.handle.net/10044/1/29337.
Texto completo da fonteKim, Sunha. "A Comparison of Discrete and Continuous Survival Analysis". Diss., Virginia Tech, 2014. http://hdl.handle.net/10919/47933.
Texto completo da fontePh. D.
Kilian, Stephanie L. "Coordination of Continuous and Discrete Components of Action". Cleveland State University / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=csu1403047071.
Texto completo da fonteDesmarais, Bruce A. Carsey Thomas M. "Discrete measurement, continuous time and event history modeling". Chapel Hill, N.C. : University of North Carolina at Chapel Hill, 2008. http://dc.lib.unc.edu/u?/etd,1900.
Texto completo da fonteTitle from electronic title page (viewed Dec. 11, 2008). "... in partial fulfillment of the requirements for the degree of Master of Political Science in the Department of Political Science." Discipline: Political Science; Department/School: Political Science.
Mayeli, Azita. "Discrete and continuous wavelet transformations on the Heisenberg group". [S.l.] : [s.n.], 2006. http://mediatum2.ub.tum.de/doc/602044/document.pdf.
Texto completo da fonteBarton, Paul Inigo. "The modelling and simulation of combined discrete/continuous processes". Thesis, Imperial College London, 1992. http://hdl.handle.net/10044/1/8478.
Texto completo da fontePerrin, Nicolas. "Footstep planning for humanoid robots: discrete and continuous approaches". Phd thesis, Institut National Polytechnique de Toulouse - INPT, 2011. http://tel.archives-ouvertes.fr/tel-00647469.
Texto completo da fonteKoshkouei, Ali Jafari. "Continuous and discrete-time sliding mode control design techniques". Thesis, University of Sheffield, 1997. http://etheses.whiterose.ac.uk/15037/.
Texto completo da fontePoufinas, Thomas. "Discrete-Time and Continuous-Time Option Pricing with Fees /". The Ohio State University, 1996. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487934589977028.
Texto completo da fonteRasolonjanahary, Manan'Iarivo. "Scaling of morphogenetic patterns in continuous and discrete models". Thesis, University of Liverpool, 2013. http://livrepository.liverpool.ac.uk/17293/.
Texto completo da fonteIngerman, David V. "Discrete and continuous inverse boundary problems on a disc /". Thesis, Connect to this title online; UW restricted, 1997. http://hdl.handle.net/1773/5756.
Texto completo da fonteRivera, G. Angel J. "Reasoning about co-evolving discrete, continuous and hybrid states". Related electronic resource: Current Research at SU : database of SU dissertations, recent titles available full text, 2008. http://wwwlib.umi.com/cr/syr/main.
Texto completo da fonteSivaramakrishnan, Kamakshi. "Universal schemes for denoising discrete-time continuous-amplitude signals /". May be available electronically:, 2008. http://proquest.umi.com/login?COPT=REJTPTU1MTUmSU5UPTAmVkVSPTI=&clientId=12498.
Texto completo da fonteLiu, Qing. "Elliptic Asymptotic Behaviours of Continuous and Discrete Painlevé Equations". Thesis, The University of Sydney, 2018. http://hdl.handle.net/2123/18883.
Texto completo da fonteNutaro, James Joseph. "Parallel discrete event simulation with application to continuous systems". Diss., The University of Arizona, 2003. http://hdl.handle.net/10150/280490.
Texto completo da fonteHu, Siyi S. M. Massachusetts Institute of Technology. "Discrete-continuous optimization for robot perception via semidefinite relaxation". Thesis, Massachusetts Institute of Technology, 2019. https://hdl.handle.net/1721.1/122515.
Texto completo da fonteCataloged from PDF version of thesis.
Includes bibliographical references (pages 85-90).
In this thesis, we propose polynomial-time algorithms based on semidefinite programming (SDP) relaxation to find approximate solutions to nonconvex problems arising in two fields of robot perception, semantic segmentation and robust pose graph optimization. Compared with other inference techniques, SDP relaxation have shown to provide accurate estimate with provable sub-optimality guarantees without relying on an initial guess for optimization. On the downside, general SDP solvers scale poorly in terms of time and memory with the problem size. However, for problems admitting low-rank solutions, low-rank solvers and smooth Riemannian optimization can speed up computation significantly. Along this direction, the first contribution is two fast and scalable techniques for inference in Markov Random Fields (MRFs). MRFs are a popular model for several pattern recognition and reconstruction problems in robotics and computer vision, but are intractable to solve in general. The first technique, named Dual Ascent Riemannian Staircase (DARS), is able to solve large problem instances in seconds. The second technique, named Fast Unconstrained SEmidefinite Solver (FUSES), utilizes a novel SDP relaxation and is able to solve similar problems in milliseconds. We benchmark both techniques in multi-class image segmentation problems against state-of-the-art MRF solvers and show that both techniques achieves comparable accuracy with the best existing solver while FUSES is much faster. Building on top of MRF models, our second contribution is a Discrete-Continuous Graphical Model (DC-GM) that combines discrete binary labeling with standard least-square pose graph optimization to identify and reject spurious measurements for Simultaneous Localization and Mapping (SLAM). We then perform inference in the DC-GM via semidefinite relaxation. Experiment results on synthetic and real benchmarking datasets show that the proposed approach compares favorably with state-of-the-art methods.
by Siyi Hu.
S.M.
S.M. Massachusetts Institute of Technology, Department of Aeronautics and Astronautics
Goda, Ibrahim. "Micromechanical models of network materials presenting internal length scales : applications to trabecular bone under stable and evolutive conditions". Thesis, Université de Lorraine, 2015. http://www.theses.fr/2015LORR0055/document.
Texto completo da fonteA methodology based on micromechanics has been developed to determine the effective behavior of network materials endowed with a discrete architecture at the microscopic level. It relies on the discrete homogenization method, which has been applied to textile monolayers and trabecular bones. The initially discrete topology of the considered network materials results after homogenization at the mesoscopic level in anisotropic micropolar effective continuum, which proves able to capture the observed internal scale effects. Such micromechanical methods are useful to remedy the difficulty to measure the effective mechanical properties at the intermediate mesoscopic level scale. The bending and torsion responses of vertebral trabecular bone beam specimens are formulated in both static and dynamic situations, based on the Cosserat theory. 3D models have been developed for describing the multiaxial yield and brittle fracture behavior of trabecular bone, including the analysis of size-dependent non-classical plastic yield. We have constructed by FE analyses a homogeneous, orthotropic couple-stress continuum model as a substitute of the 3D periodic heterogeneous cellular solid model of vertebral trabecular bone, based on the equivalent strain energy approach. Bone tissues are able to adapt their local density and load bearing capacities as well as their size and shape to mechanical stimuli. We have developed models for combined internal and external bone remodeling in the framework of the thermodynamics of irreversible processes, at both the cellular and macroscopic levels. We lastly combined anisotropic internal remodeling with fatigue continuum damage
Xu, Kun. "Static hedging of barrier options in discrete and continuous time". Thesis, Uppsala University, Department of Mathematics, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-120232.
Texto completo da fonteDimtriadish, Veniamin. "Modelling, safety verification and design of discrete/continuous processing systems". Thesis, Imperial College London, 1997. http://hdl.handle.net/10044/1/7263.
Texto completo da fonteKristensson, Per Ola. "Discrete and Continuous Shape Writing for Text Entry and Control". Doctoral thesis, Linköping : Department of Computer and Information Science, Linköping University, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-8877.
Texto completo da fonteChaves, Madalena. "Predictive analysis of dynamical systems: combining discrete and continuous formalisms". Habilitation à diriger des recherches, Université Nice Sophia Antipolis, 2013. http://tel.archives-ouvertes.fr/tel-00908927.
Texto completo da fonteOuaknine, Joel. "Discrete analysis of continuous behaviour in real-time concurrent systems". Thesis, University of Oxford, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.365293.
Texto completo da fontePerreira, Das Chagas Thiago. "Stabilization of periodic orbits in discrete and continuous-time systems". Phd thesis, Université Paris Sud - Paris XI, 2013. http://tel.archives-ouvertes.fr/tel-00852424.
Texto completo da fonteYpma, J. Y. "Dynamic models of continuous and discrete outcomes : methods and applications". Thesis, University College London (University of London), 2013. http://discovery.ucl.ac.uk/1386923/.
Texto completo da fonteRao, V. A. P. "Markov chain Monte Carlo for continuous-time discrete-state systems". Thesis, University College London (University of London), 2012. http://discovery.ucl.ac.uk/1349490/.
Texto completo da fonteChagas, Thiago Pereira das. "Stabilization of periodic orbits in discrete and continuous-time systems". Instituto Tecnológico de Aeronáutica, 2013. http://www.bd.bibl.ita.br/tde_busca/arquivo.php?codArquivo=2770.
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