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Dave, Jagrut Durdant. "Parallel Discrete Event Simulation Techniques for Scientific Simulations". Thesis, Georgia Institute of Technology, 2005. http://hdl.handle.net/1853/6942.
Pełny tekst źródłaSvensson, Henrik. "Simulations". Doctoral thesis, Linköpings universitet, Institutionen för datavetenskap, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-98050.
Pełny tekst źródłaPawlik, Amadeusz, i Henry Andersson. "Visualising Interval-Based Simulations". Thesis, Högskolan i Halmstad, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-28592.
Pełny tekst źródłaHuang, Ya-Lin. "Ad hoc distributed simulation: a method for embedded online simulations". Diss., Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/49060.
Pełny tekst źródłaAndersson, Håkan. "Parallel Simulation : Parallel computing for high performance LTE radio network simulations". Thesis, Mittuniversitetet, Institutionen för informationsteknologi och medier, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:miun:diva-12390.
Pełny tekst źródłaSingh, Harpreet. "Computer simulations of realistic microstructures implications for simulation-based materials design/". Diss., Atlanta, Ga. : Georgia Institute of Technology, 2007. http://hdl.handle.net/1853/22564.
Pełny tekst źródłaCommittee Chair: Dr. Arun Gokhale; Committee Member: Dr. Hamid Garmestani; Committee Member: Dr. Karl Jacob; Committee Member: Dr. Meilin Liu; Committee Member: Dr. Steve Johnson.
Strauss, Martin. "Dynamic market simulations". Zürich : ETH, Eidgenössische Technische Hochschule Zürich, Dept. für Informatik, 2001. http://e-collection.ethbib.ethz.ch/show?type=dipl&nr=45.
Pełny tekst źródłaMartin, Bruno. "Simulations d'automates cellulaires". Habilitation à diriger des recherches, Université de Nice Sophia-Antipolis, 2005. http://tel.archives-ouvertes.fr/tel-00212057.
Pełny tekst źródłaRautio, R. P. (Riku-Petteri). "Cosmological Zoom simulations". Bachelor's thesis, University of Oulu, 2016. http://urn.fi/URN:NBN:fi:oulu-201610272951.
Pełny tekst źródłaYaiche, Francis. "Les simulations globales". Paris 3, 1993. http://www.theses.fr/1994PA030012.
Pełny tekst źródłaToday people talk a lot about global simulations in the area of language teaching. This thesis introduces six "general" canvases and four used in teaching the language to specific group (developed at belc since 1973). A global simulation is a type of educational game which consists of launching a group of pupils in to an imaginary identity and also in to a plays which is a theme (such as an island, a block of flats, a village, a circus, a hotel, etc. ) where the teacher uses oral and written exercises. This way of allowing the real world to came into the classroom is also a way of allowing the pupils to talk about life, love and death, and to remove blockages and inhitions which hinder the learning process. Indeed global simulations force people to reconsider certain aspects about the teacherlearner-learning relationship and to think about questions which wer raised by the new educational gift : how could they save the class from boredom ? could pupils play and learn at the same time ? what roles does the teacher play? and the pupil? how can a teacher correct and assess the result of a game? a global simulation is therefore a place where the learning of a language and a culture, the knowledge of oneself and of others can be built on
Gutiérrez, Daniel. "Green Fuel Simulations". Thesis, Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-79244.
Pełny tekst źródłaTarmyshov, Konstantin B. "Molecular dynamics simulations". Phd thesis, [S.l.] : [s.n.], 2007. https://tuprints.ulb.tu-darmstadt.de/787/1/000_pdfsam_PhD_thesis_-_All_-_LinuxPS2PDF.ps.pdf.
Pełny tekst źródłaFong, Heung Wah. "Editing explosion simulations /". View abstract or full-text, 2004. http://library.ust.hk/cgi/db/thesis.pl?COMP%202004%20FONG.
Pełny tekst źródłaIncludes bibliographical references (leaves 69-71). Also available in electronic version. Access restricted to campus users.
Jain, Sunny. "Hypersonic nonequilibrium flow simulations over a blunt body using bgk simulations". [College Station, Tex. : Texas A&M University, 2007. http://hdl.handle.net/1969.1/ETD-TAMU-2406.
Pełny tekst źródłaLyu, Yeonhwan. "Simulations and Second / Foreign Language Learning: Improving communication skills through simulations". See Full Text at OhioLINK ETD Center (Requires Adobe Acrobat Reader for viewing), 2006. http://www.ohiolink.edu/etd/view.cgi?toledo1147363791.
Pełny tekst źródłaBuchta, Christian, i Sara Dolnicar. "Learning by simulation. Computer simulations for strategic marketing decision support in tourism". SFB Adaptive Information Systems and Modelling in Economics and Management Science, WU Vienna University of Economics and Business, 2003. http://epub.wu.ac.at/1718/1/document.pdf.
Pełny tekst źródłaSeries: Report Series SFB "Adaptive Information Systems and Modelling in Economics and Management Science"
Leveugle, Benoît. "Simulation DNS de l’interaction flamme-paroi dans les moteurs à allumage commandé". Thesis, Rouen, INSA, 2012. http://www.theses.fr/2012ISAM0021/document.
Pełny tekst źródłaUnder the INTERMARC project (Flame wall interaction in spark ignition engines), CORIA's job was to produce a database to RANS scale (from DNS data) to test, validate and modify the interaction model developed by IFPEN. This model aims the addition of the interaction phenomena, non-captured by the current wall laws. This project is based on the strong interaction between the different actors. The CORIA and the CETHIL have worked together in the creation of the database, where the experimental data were also used to validate the resuslts of the DNS code.CORIA then used this database to test the original model proposed by IFPPEN, then according to the results obtained, CORIA iterated with IFPEN to modify and improve the models. These tests included laminar 2D simulations, 2D turbulent and 3D turbulent simulations
Celik, Nurcin. "INTEGRATED DECISION MAKING FOR PLANNING AND CONTROL OF DISTRIBUTED MANUFACTURING ENTERPRISES USING DYNAMIC-DATA-DRIVEN ADAPTIVE MULTI-SCALE SIMULATIONS (DDDAMS)". Diss., The University of Arizona, 2010. http://hdl.handle.net/10150/195427.
Pełny tekst źródłaStucki, Pascal. "Obstacles in pedestrian simulations". Zürich : ETH, Eidgenössische Technische Hochschule Zürich, Department of Computer Science, 2003. http://e-collection.ethbib.ethz.ch/show?type=dipl&nr=129.
Pełny tekst źródłaBarakat, Firas Risnes. "Simulations of imitative learning". Thesis, Norwegian University of Science and Technology, Department of Computer and Information Science, 2006. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-10108.
Pełny tekst źródłaThis Master thesis presents simulations within the field of imitative learning. The thesis starts with a review of the work done in my depth study, looking at imitative learning in general. Further, forward and inverse models are studied, and a case study of a Wolpert et al article is done. An architecture using the recurrent neural network with parametric bias (RNNPB) and a PID-controller by Tani et al is presented, and later simulated using MATLAB and the breve simulation environment. It is tested if the RNNPB is suitable for imitative learning. The first experiment was quite successful, and interesting results were discovered. The second experiment was less successful. Generally, it was confirmed that RNNPB is able to reproduce actions, interact with the environment, and indicate situations using the parametric bias (PB). It was also observed that the PB values tend to reflect common characteristics in similar training patterns. A comparison between the forward and inverse model and the RNNPB model was done. The former appears to be more modular and a predictor of consequence of actions, while the latter predicts sequences and is able to represent the situation it is in. The work done to connect MATLAB and breve is also presented.
Feldmeier, Achim, Wolf-Rainer Hamann, D. Rätzel i Lidia M. Oskinova. "Hydrodynamic simulations of clumps". Universität Potsdam, 2007. http://opus.kobv.de/ubp/volltexte/2008/1797/.
Pełny tekst źródłaSigurjonsson, Kjartan Örn. "Dual gradient drilling simulations". Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for petroleumsteknologi og anvendt geofysikk, 2012. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-18362.
Pełny tekst źródłaBanon, Navarro Alejandro. "Gyrokinetic large Eddy simulations". Doctoral thesis, Universite Libre de Bruxelles, 2012. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/209592.
Pełny tekst źródłaDu point de vue théorique, la turbulence plasma est décrite par les équations gyrocinétiques, un ensemble d équations aux dérivées partielles non linéaires couplées. Par suite des très différentes échelles spatiales mises en jeu dans des conditions expérimentales réelles, une simulation numérique directe et complète (DNS) de la turbulence gyrocinétique est totalement hors de portée des plus puissants calculateurs actuels, de sorte que démontrer la faisabilité d’une alternative permettant de réduire l’effort numérique est primordiale. En particulier, les simulations de grandes échelles (”Large-Eddy Simulations” - LES) constituent un candidat pertinent pour permettre une telle r éduction. Les techniques LES ont initialement été développées pour les simulations de fluides turbulents à haut nombre de Reynolds. Dans ces simulations, les plus grandes échelles sont explicitement simulées numériquement, alors que l’influence des plus petites est prise en compte via un modèle implémenté dans le code.
Cette thèse présente les premiers développements de techniques LES dans le cadre des équations gyrocinétiques (GyroLES). La modélisation des plus petites échelles est basée sur des bilans d’énergie libre. En effet, l’energie libre joue un rôle important dans la théorie gyrocinétique car elle en est un invariant non lin éaire bien connu. Il est démontré que sa dynamique partage de nombreuses propriétés avec le transfert d’energie dans la turbulence fluide. En particulier, il est montré l’existence d’une cascade d énergie libre, fortement locale et dirigée des grandes échelles vers les petites, dans le plan perpendiculaire â celui du champ magnétique ambiant.
La technique GyroLES est aujourd’hui implantée dans le code GENE et a été testée avec succès pour les instabilités de gradient de température ionique (ITG), connues pour jouer un rôle crucial dans la micro-turbulence gyrocinétique. A l’aide des GyroLES, le spectre du flux de chaleur obtenu dans des simulations à très hautes résolutions est correctement reproduit, et ce avec un gain d’un facteur 20 en termes de coût numérique. Pour ces raisons, les simulations gyrocinétiques GyroLES sont potentiellement un excellent candidat pour réduire l’effort numérique des codes gyrocinétiques actuels.
/ Anomalous transport due to plasma micro-turbulence is known to play an important role in confinement properties of magnetically confined fusion plasma devices such as ITER. Indeed, plasma turbulence is strongly connected to the energy confinement time, a key issue in thermonuclear fusion research. Plasma turbulence is described by the gyrokinetic equations, a set of nonlinear partial differential equations. Due to the various scales characterizing the turbulent fluctuations in realistic experimental conditions, Direct Numerical Simulations (DNS) of gyrokinetic turbulence remain close to the computational limit of current supercomputers, so that any alternative is welcome to decrease the numerical effort. In particular, Large-Eddy Simulations (LES) are a good candidate for such a decrease. LES techniques have been devised for simulating turbulent fluids at high Reynolds number. In these simulations, the large scales are computed explicitly while the influence of the smallest scales is modeled.
In this thesis, we present for the first time the development of the LES for gyrokinetics (GyroLES). The modeling of the smallest scales is based on free energy diagnostics. Indeed, free energy plays an important role in gyrokinetic theory, since it is known to be a nonlinear invariant. It is shown that its dynamics share many properties with the energy transfer in fluid turbulence. In particular, one finds a (strongly) local, forward (from large to small scales) cascade of free energy in the plane perpendicular to the background magnetic field.
The GyroLES technique is implemented in the gyrokinetic code Gene and successfully tested for the ion temperature gradient instability (ITG), since ITG is suspected to play a crucial role in gyrokinetic micro-turbulence. Employing GyroLES, the heat flux spectra obtained from highly resolved direct numerical simulations are recovered. It is shown that the gain of GyroLES runs is 20 in terms of computational time. For this reason, Gyrokinetic Large Eddy Simulations can be considered a serious candidate to reduce the numerical cost of gyrokinetic simulations.
Doctorat en Sciences
info:eu-repo/semantics/nonPublished
Sliozberg, Yelena R. Abrams Cameron F. "Molecular simulations of chaperonins /". Philadelphia, Pa. : Drexel University, 2007. http://hdl.handle.net/1860/1871.
Pełny tekst źródłaBanfield, Robert E. "Learning on complex simulations". [Tampa, Fla.] : University of South Florida, 2007. http://purl.fcla.edu/usf/dc/et/SFE0002112.
Pełny tekst źródłaWong, Jeffrey. "Simulations of Surfactant Spreading". Scholarship @ Claremont, 2011. http://scholarship.claremont.edu/hmc_theses/1.
Pełny tekst źródłaErikson, Lars. "Automatic Well Control Simulations". Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for petroleumsteknologi og anvendt geofysikk, 2012. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-18381.
Pełny tekst źródłaRaicevic, Milan. "Simulations of cosmic reionization". Thesis, Durham University, 2010. http://etheses.dur.ac.uk/323/.
Pełny tekst źródłaArcher, T. D. "Computer simulations of calcite". Thesis, University of Cambridge, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.596141.
Pełny tekst źródłaSak, Halis. "Efficient Simulations in Finance". Department of Statistics and Mathematics, WU Vienna University of Economics and Business, 2008. http://epub.wu.ac.at/1068/1/document.pdf.
Pełny tekst źródłaSeries: Research Report Series / Department of Statistics and Mathematics
Smith, Gregory K. "Simulations of chemical catalysis". Thesis, The University of New Mexico, 2014. http://pqdtopen.proquest.com/#viewpdf?dispub=3612623.
Pełny tekst źródłaThis dissertation contains simulations of chemical catalysis in both biological and heterogeneous contexts. A mixture of classical, quantum, and hybrid techniques are applied to explore the energy profiles and compare possible chemical mechanisms both within the context of human and bacterial enzymes, as well as exploring surface reactions on a metal catalyst. A brief summary of each project follows.
Project 1 - Bacterial Enzyme SpvC
The newly discovered SpvC effector protein from Salmonella typhimurium interferes with the host immune response by dephosphorylating mitogen-activated protein kinases (MAPKs) with a β-elimination mechanism. The dynamics of the enzyme substrate complex of the SpvC effector is investigated with a 3.2 ns molecular dynamics simulation, which reveals that the phosphorylated peptide substrate is tightly held in the active site by a hydrogen bond network and the lysine general base is positioned for the abstraction of the alpha hydrogen. The catalysis is further modeled with density functional theory (DFT) in a truncated active-site model at the B3LYP/6-31 G(d,p) level of theory. The truncated model suggested the reaction proceeds via a single transition state. After including the enzyme environment in ab initio QM/MM studies, it was found to proceed via an E1cB-like pathway, in which the carbanion intermediate is stabilized by an enzyme oxyanion hole provided by Lys104 and Tyr158 of SpvC.
Project 2 - Human Enzyme CDK2
Phosphorylation reactions catalyzed by kinases and phosphatases play an indispensable role in cellular signaling, and their malfunctioning is implicated in many diseases. Ab initio quantum mechanical/molecular mechanical studies are reported for the phosphoryl transfer reaction catalyzed by a cyclin-dependent kinase, CDK2. Our results suggest that an active-site Asp residue, rather than ATP as previously proposed, serves as the general base to activate the Ser nucleophile. The corresponding transition state features a dissociative, metaphosphate-like structure, stabilized by the Mg(II) ion and several hydrogen bonds. The calculated free-energy barrier is consistent with experimental values.
Project 3 - Bacterial Enzyme Anthrax Lethal Factor
In this dissertation, we report a hybrid quantum mechanical and molecular mechanical study of the catalysis of anthrax lethal factor, an important first step in designing inhibitors to help treat this powerful bacterial toxin. The calculations suggest that the zinc peptidase uses the same general base-general acid mechanism as in thermolysin and carboxypeptidase A, in which a zinc-bound water is activated by Glu687 to nucleophilically attack the scissile carbonyl carbon in the substrate. The catalysis is aided by an oxyanion hole formed by the zinc ion and the side chain of Tyr728, which provide stabilization for the fractionally charged carbonyl oxygen.
Project 4 - Methanol Steam Reforming on PdZn alloy
Recent experiments suggested that PdZn alloy on ZnO support is a very active and selective catalyst for methanol steam reforming (MSR). Plane-wave density functional theory calculations were carried out on the initial steps of MSR on both PdZn and ZnO surfaces. Our calculations indicate that the dissociation of both methanol and water is highly activated on flat surfaces of PdZn such as (111) and (100), while the dissociation barriers can be lowered significantly by surface defects, represented here by the (221), (110), and (321) faces of PdZn. The corresponding processes on the polar Zn-terminated ZnO(0001) surfaces are found to have low or null barriers. Implications of these results for both MSR and low temperature mechanisms are discussed.
Hamilton, Angela. "Simulations for Financial Literacy". Master's thesis, University of Central Florida, 2012. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/5235.
Pełny tekst źródłaID: 031001493; System requirements: World Wide Web browser and PDF reader.; Mode of access: World Wide Web.; Adviser: Dan Jones.; Title from PDF title page (viewed July 25, 2013).; Thesis (M.A.)--University of Central Florida, 2012.; Includes bibliographical references (p. 76-80).
M.A.
Masters
English
Arts and Humanities
English; Technical Communications
Raveendran, Karthik. "Control of liquid simulations". Diss., Georgia Institute of Technology, 2014. http://hdl.handle.net/1853/53011.
Pełny tekst źródłaJennings, Vincent Louis. "Computational simulations of titanates". Thesis, University of Warwick, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.398737.
Pełny tekst źródłaChappell, Helen Fiona. "Atomistic simulations of hydroxyapatite". Thesis, University of Cambridge, 2007. https://www.repository.cam.ac.uk/handle/1810/290022.
Pełny tekst źródłaNagy, Lesleis. "Parallelisation of micromagnetic simulations". Thesis, University of Edinburgh, 2016. http://hdl.handle.net/1842/20433.
Pełny tekst źródłaÖqvist, Mona. "Numerical simulations of wear". Licentiate thesis, Luleå tekniska universitet, 2000. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-26185.
Pełny tekst źródłaGodkänd; 2000; 20070317 (ysko)
Penny, Matthew Thomas. "Simulations of gravitational microlensing". Thesis, University of Manchester, 2011. https://www.research.manchester.ac.uk/portal/en/theses/simulations-of-gravitational-microlensing(ddc24ee8-c2a6-432a-a168-7d56662a9247).html.
Pełny tekst źródłaTara, Sylvia. "Computer simulations of acetylcholinesterase /". Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 1998. http://wwwlib.umi.com/cr/ucsd/fullcit?p9908501.
Pełny tekst źródłaChen, Chi-Shao. "Equatorial entrainment zone simulations". Thesis, Monterey, California : Naval Postgraduate School, 1990. http://handle.dtic.mil/100.2/ADA237234.
Pełny tekst źródłaThesis Advisor(s): Garwood, Roland W. Second Reader: Chu, Pecheng. "June 1990." Description based on signature page as viewed on October 19, 2009. DTIC Identifier(s): Air water interactions, ocean models, ocean currents, entrainment, ocean circulation, heat flux, wind velocity, mathematical prediction, equatorial regions, theses. Author(s) subject terms: Air-sea interaction, equatorial circulation. Includes bibliographical references (p. 73-75). Also available in print.
Prière, Céline Poinsot Thierry. "Simulations aux grandes échelles". Toulouse : INP Toulouse, 2005. http://ethesis.inp-toulouse.fr/archive/00000098.
Pełny tekst źródłaRamakrishnan, Siddharth. "Proving Ground Durability Simulations". Thesis, KTH, Maskinkonstruktion (Avd.), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-259664.
Pełny tekst źródłaVirtuell hållfasthetsprovning utnyttjats inom fordonsindustrin för att komplettera fysisk provning med avseende att konstruera hållfasta fordon. Simuleringar är användbara för att kontrollera designen innan första prototypen har byggts men även för att kontrollera hur hållfastheten påverkas av olika fordonskoncept. Bussar utvecklas och provas så att de ska klara målen för hållfasthet innan de säljs. Busstillverkarna använder speciella provbanor bestående av olika hinder och manövrar för att testa hållfastheten. Tillsammans med speciella provningsprogram som specificerar vilka provbanehinder och manövrar som bussen ska provas enligt kan hållfastheten säkerställas. Dessa provprogram är framtagna för att den accelererade utmattningen på provbanan ska matcha den utmattning bussen utsätt för hos kund. Denna avhandling undersöker huruvida provprogram kan utvecklas digitalt via simuleringar. Multidynamiska modeller av bussens delsystem modelleras i programvaran MSC ADAMS. Delsystem som buss chassi ram och axlar modelleras som flexibla då deras dynamik egenskaper anses påverka simuleringsresultaten. Den virtuella bussen provas på en digital provbanan. Krafterna i reaktionsstag, kränghämmare, axlar och förskjutningen i stötdämpare beräknas. Dessa kraft- och förskjutningssignalser används senare för att beräkna utmattning. Simulerade resultat av ett hinder jämförs med resultat från fysisk provning för att därefter justera vissa parametrar för att virtuella resultat ska matcha fysiska. Efter att modellen är optimerad kan slutligen delskadan för ett helt provprogram simuleras. Resultat visar på att en väll optimerad simuleringsmodell är nödvändig för att simulera fram provprogram med bra noggrannhet. Att jämföra simulerade resultat med fysiska ska göras med viss aktsamhet då den fysiska bussen bör vara identisk med den virtuella; vilket är mycket svårt att uppnå. Framtida arbete inom ämnet bör innefatta förbättringar av simuleringsnoggrannheten och använda simulering för framtagandet av nya hinder/manövrar för att förbättra befintliga provprogram.
Beersing-Vasquez, Kiran. "Suturing in Surgical Simulations". Thesis, KTH, Numerisk analys, NA, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-260254.
Pełny tekst źródłaDet här projektet syftar till att utveckla mjukvara för virtuell simulering av kirurgi som involverar knytande av suturtråd. Lagranges ekvationer används för att härleda energibevarande tillståndsekvationer. Lösningsmetoderna grundar sig i teori från området Differential-Algebraiska Ekvationer (DAEer), som avser att kontrollera Ordinära Differentialekvationer (ODEer) med algebraiska bivillkor. Ett implicit integrationsschema och Newtons metod används för att lösa systemet i varje steg. Utöver det så implementeras en kollisionsrespons-process baserad på det linjära komplementaritetsproblemet (LCP) för att hantera kollisioner och mäta deras krafter. Modeller har utvecklats för att representera olika typer av objekt. En spline-modell används för att representera suturtråden och ett mass-fjäder system för vävnaden. Valet baserades på deras höga prestanda samt starka anknytning till objektens fysiska egenskaper. Spline-modellen valdes också då dess kontinuitet innebär att den går att evaluera för en godtycklig punkt inom dess domän. Andra objekt, såsom stela kroppar, finns också definierade. Lagrangemultiplikator används för att definiera bivillkor i modellen. Detta tillåter konstruktionen av komplexa modeller. Ett viktigt bivillkor är sutur-bivillkoret som uppstår när tillräcklig kraft från spetsen på den kirurgiska nålen appliceras på vävnaden. Detta bivillkor tillåter att endast en glidande punkt längsmed suturen passerar genom en specifik punkt på vävnaden. Detta resulterar i en virtuell modell för stygn som kan byggas vidare på för användning i kirurgiska simulationer. Det vore intressant med ytterligare undersökningar för att förbättra prestandan, precisionen och simulatorns omfattning.
Predari, Maria. "Load balancing for parallel coupled simulations". Thesis, Bordeaux, 2016. http://www.theses.fr/2016BORD0369/document.
Pełny tekst źródłaLoad balancing is an important step conditioning the performance of parallel applications. The goal is to distribute roughly equal amounts of computational load across a number of processors, while minimising interprocessor communication. A common approach to model the problem is based on graph structures and graph partitioning algorithms. Moreover, new challenges involve the simulation of more complex physical phenomena, where different parts of the computational domain exhibit different physical behavior. Such simulations follow the paradigm of multi-physics or multi-scale modeling approaches. Combining such different models in massively parallel computations is still a challenge to reach high performance. Additionally, traditional load balancing algorithms are often inadequate, and more sophisticated solutions should be explored. In this thesis, we propose new graph partitioning algorithms that balance the load of such simulations, refered to as co-partitioning. We formulate this problem with the use of graph partitioning with initially fixed vertices which we believe represents efficiently the additional constraints of coupled simulations. We have therefore developed a direct algorithm for graph partitioning that manages successfully problems with fixed vertices. The algorithm is implemented inside Scotch partitioner and a series of experiments were carried out on the DIMACS graph collection. Moreover we proposed three copartitioning algorithms that respect the constraints of the respective coupled codes. We finally validated our algorithms by an experimental study comparing our methods with current strategies on artificial cases and on real-life coupled simulations
Falcigno, Steven V. "The Simulation Engine, a platform for developing industrial process knowledge-based discrete event simulations". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape16/PQDD_0009/MQ33370.pdf.
Pełny tekst źródłaBalasubramanian, Sivaramakrishnan. "A Novel Approach for the Direct Simulation of Subgrid-Scale Physics in Fire Simulations". NCSU, 2010. http://www.lib.ncsu.edu/theses/available/etd-12212009-122246/.
Pełny tekst źródłaGuesnet, Étienne. "Modélisation du comportement mécanique et thermique des silices nano-architecturées". Thesis, Université Grenoble Alpes (ComUE), 2018. http://www.theses.fr/2018GREAI075/document.
Pełny tekst źródłaNanostructured silicas are ultra-porous materials (more than 80 % porosity) used to make Vacuum Insulation Panels (VIP).They have exceptional thermal properties, but poor mechanical properties. The goal of this thesis is to study these materials at the scale of the particle (a few nm), the aggregate of particles (a few tens of nm) and the agglomerate of aggregates (a few hundred nm), in order to better understand mechanical and thermal behaviour using simulations, and to propose ways to improve the thermal / mechanical compromise. The particulate nature of the material and its multi-scale naturejustify the use of Discrete Element Methods (DEM). An original model allowing to generate aggregates with controlledmorphology (fractal dimension, radius of gyration, porosity) is proposed. The compaction behaviour of the aggregates is then studied by DEM. A low-density cycling approach has been developed to obtain realistic initial aggregate arrangements.The preponderance of adhesive phenomena in the system makes it very sensitive to the initial arrangement. The tensile response of structures generated by compaction is also evaluated. The influence of aggregate morphology, adhesion and friction were studied. Emphasis is placed on the comparison of two types of silica (pyrogenic and precipitated) with different morphologies and for which experimental data allow a comparison with simulations. The simulations presented allow us to provide answers on the origin of the differences in mechanical behaviour observed experimentally for these two types of silica.A modeling of the thermal conductivity of the material, with a focus on solid conductivity, is also proposed
ABDEL-MOMEN, SHERIF SAMIR. "DYNAMIC RESOURCE BALANCING BETWEEN TWO COUPLED SIMULATIONS". University of Cincinnati / OhioLINK, 2003. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1060893659.
Pełny tekst źródłaLinke, Gunnar Torsten. "Eigenschaften fluider Vesikeln bei endlichen Temperaturen". Phd thesis, Universität Potsdam, 2005. http://opus.kobv.de/ubp/volltexte/2005/583/.
Pełny tekst źródłaDie Form für eine freie fluide Vesikel mit frei veränderlichem Volumen, die das Konfigurationsenergie-Funktional minimiert, ist im Falle verschwindender Temperatur eine Kugel. Mit Hilfe von Monte-Carlo-Simulationen sowie einem analytisch behandelbaren Modellsystem konnte gezeigt werden, daß sich dieses Ergebnis nicht auf endliche Temperaturen verallgemeinern lässt und statt dessen leicht prolate und oblate Vesikelformen gegenüber der Kugelgestalt überwiegen. Dabei ist die Wahrscheinlichkeit für eine prolate Form ein wenig gröoßer als für eine oblate. Diese spontane Asphärizität ist entropischen Ursprungs und tritt nicht bei zweidimensionalen Vesikeln auf. Durch osmotische Drücke in der Vesikel, die größer sind als in der umgebenden Flüssigkeit, lässt sich die Asphärizität reduzieren oder sogar kompensieren. Die Übergänge zwischen den beobachteten prolaten und oblaten Formen erfolgen im Bereich von Millisekunden in Abwesenheit osmotisch aktiver Partikel. Bei Vorhandensein derartiger Partikel ergeben sich Übergangszeiten im Bereich von Sekunden.
Im Rahmen der Untersuchung des Adhäsionsverhaltens fluider Vesikeln an planaren, homogenen Substraten konnte mit Hilfe von Monte-Carlo-Simulationen festgestellt werden, dass die Eigenschaften der Kontaktfläche der Vesikeln stark davon abhängen, welche Kräfte den Kontakt bewirken. Für eine dominierende attraktive Wechselwirkung zwischen Substrat und Vesikelmembran sowie im Falle eines Massendichteunterschieds der Flüssigkeiten innerhalb und außerhalb der Vesikel, der die Vesikel auf das Substrat sinken lässt, ndet man innerhalb der Kontakt ache eine ortsunabhangige Verteilung des Abstands zwischen Vesikelmembran und Substrat. Drückt die Vesikel ohne Berücksichtigung osmotischer Effekte auf Grund einer Differenz der Massendichten der Membran und der umgebenden Flüssigkeit gegen das Substrat, so erhält man eine Abstandsverteilung zwischen Vesikelmembran und Substrat, die mit dem Abstand vom Rand der Kontaktfläche variiert. Dieser Effekt ist zudem temperaturabhängig.
Ferner wurde die Adhäsion fluider Vesikeln an chemisch strukturierten planaren Substraten untersucht. Durch das Wechselspiel von entropischen Eekten und Konfigurationsenergien entsteht eine komplexe Abhängigkeit der Vesikelform von Biegesteifigkeit, osmotischen Bedingungen und der Geometrie der attraktiven Domänen.
Für die Bestimmung der Biegesteifigkeit der Vesikelmembranen liefern die existierenden Verfahren stark voneinander abweichende Ergebnisse. In der vorliegenden Arbeit konnte mittels Monte-Carlo-Simulationen zur Bestimmung der Biegesteifigkeit anhand des Mikropipettenverfahrens von Evans gezeigt werden, dass dieses Verfahren die a priori für die Simulation vorgegebene Biegesteifigkeit im wesentlichen reproduzieren kann.
Im Hinblick auf medizinisch-pharmazeutische Anwendungen ist der Durchgang fluider Vesikeln durch enge Poren relevant. In Monte-Carlo-Simulationen konnte gezeigt werden, dass ein spontaner Transport der Vesikel durch ein Konzentrationsgefälle osmotisch aktiver Substanzen, das den physiologischen Bedingungen entspricht, induziert werden kann. Es konnten die hierfür notwendigen osmotischen Bedingungen sowie die charakteristischen Zeitskalen abgeschätzt werden. Im realen Experiment sind Eindringzeiten in eine enge Pore im Bereich weniger Minuten zu erwarten. Ferner konnte beobachtet werden, dass bei Vesikeln mit einer homogenen, positiven spontanen Krümmung Deformationen hin zu prolaten Formen leichter erfolgen als bei Vesikeln ohne spontane Krümmung. Mit diesem Effekt ist eine Verringerung der Energiebarriere für das Eindringen in eine Pore verbunden, deren Radius nur wenig kleiner als der Vesikelradius ist.
In this thesis, the properties of closed fluid membranes or vesicles are studied at finite temperatures. The work contains investigations of the shape of free vesicles, studies of the adhesion behavior of vesicles to planar substrates, and investigations of the properties of fluid vesicles in confined geometries. The investigations have been performed with Monte Carlo simulations of triangulated vesicles. The statistical properties of fluctuating vesicles have been analyzed in detail by means of free energy profiles. In this context, a new histogram method was developed.
The shape of minimum configurational energy for a free vesicle without volume constraint at zero temperature is a sphere. It is shown by means of Monte Carlo simulations and a model which can be analyzed analytically, that this result does not apply to finite temperatures. Instead, prolate and oblate shapes prevail and the probability for a prolate shape is slightly larger than that for an oblate shape. This spontaneous asphericity is of entropic origin and cannot be observed in two dimensions. Osmotic pressures inside the vesicle that are larger than in the surrounding liquid may reduce or even compensate the asphericity. The transitions between the observed prolate and oblate states occur on the time scale of milliseconds in the absence of osmotically active particles and on the time scale of seconds in the presence of osmotically active particles.
As far as the adhesion behavior of fluid vesicles to planar homogeneous substrates is concerned, Monte Carlo simulations reveal a strong dependence of the properties of the contact area on its driving force. In the case of a dominating attractive interaction between vesicle membran and substrate as well as for a mass density difference of the liquids inside and outside the vesicle, which push the vesicle against the substrate, the distribution of the distance between the vesicle membrane and the substrate is homogenous. If the vesicle is pushed against the substrate by a difference of the mass densities of the membrane and the surrounding liquid, neglecting all osmotic effects, one gets a distance distribution between the vesicle membrane and the substrate which varies with the distance from the rim of the contact area. Moreover, this effect is temperature-dependent.
Furthermore, the adhesion of fluid vesicles to chemically structured planar substrates has been studied. The interplay between entropic effects and configurational energies causes a complex dependence of the vesicle shape on the bending rigidity, osmotic conditions, and the geometry of the attractive domains.
There are several experimental methods for measuring the bending rigidity of vesicle membranes which lead to rather different results for the numerical value. Monte Carlo simulations of Evans' micropipette method show that the difference between the measured bending rigidity and the a priori chosen bending rigidity is small.
The passage of fluid vesicles through narrow pores has some relevance to medical/pharmaceutical applications. In Monte Carlo simulations it is shown that a spontaneous transport of vesicles can be induced by a concentration gradient of osmotically active particles which corresponds to the physiological conditions. The necessary osmotic conditions and the charateristic time scales are calculated. For real experiments, penetration into the pore should occur within a few minutes. Moreover, it was observed that vesicles with a homogeneous positive spontaneous curvature can be deformed more easily into prolate shapes than vesicles with zero spontaneous curvature. This effect leads to a decrease of the energy barrier for the penetration into a wide pore, which has a radius slightly smaller than that of the vesicle.
Jelinek, Bohumir. "Molecular dynamics simulations of metals". Diss., Mississippi State : Mississippi State University, 2008. http://library.msstate.edu/etd/show.asp?etd=etd-11072008-130216.
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