Dissertations / Theses: 'Nonlinear analysis'

1

Gao, Pei. "Nonlinear independent component analysis." Thesis, University of Newcastle Upon Tyne, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.437979.

Full text

APA, Harvard, Vancouver, ISO, and other styles

2

Der, Ralf, Ulrich Steinmetz, Gerd Balzuweit, and Gerrit Schüürmann. "Nonlinear principal component analysis." Universität Leipzig, 1998. https://ul.qucosa.de/id/qucosa%3A34520.

Full text

Abstract:

We study the extraction of nonlinear data models in high-dimensional spaces with modified self-organizing maps. We present a general algorithm which maps low-dimensional lattices into high-dimensional data manifolds without violation of topology. The approach is based on a new principle exploiting the specific dynamical properties of the first order phase transition induced by the noise of the data. Moreover we present a second algorithm for the extraction of generalized principal curves comprising disconnected and branching manifolds. The performance of the algorithm is demonstrated for both one- and two-dimensional principal manifolds and also for the case of sparse data sets. As an application we reveal cluster structures in a set of real world data from the domain of ecotoxicology.

APA, Harvard, Vancouver, ISO, and other styles

3

Li, Ruo-Ding. "Model analysis in nonlinear optics." Doctoral thesis, Universite Libre de Bruxelles, 1991. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/213005.

Full text

APA, Harvard, Vancouver, ISO, and other styles

4

Racicot, Daniel M. "Nonlinear analysis of interspike intervals." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp05/mq20944.pdf.

Full text

APA, Harvard, Vancouver, ISO, and other styles

5

Shin, Haksik. "Nonlinear analysis of axisymmetric shells." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape4/PQDD_0017/MQ58505.pdf.

Full text

APA, Harvard, Vancouver, ISO, and other styles

6

Schaedlich, Mirko. "Nonlinear transient structural response analysis." Thesis, University of Southampton, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.438667.

Full text

APA, Harvard, Vancouver, ISO, and other styles

7

Lohmiller, Winfried Stefan 1971. "Contraction analysis of nonlinear systems." Thesis, Massachusetts Institute of Technology, 1999. http://hdl.handle.net/1721.1/9793.

Full text

Abstract:

Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1999.
Includes bibliographical references (leaves 87-90).
This thesis derives new results in nonlinear system analysis using methods inspired from fluid mechanics and differential geometry. Based on a differential analysis of convergence, these results may be viewed as generalizing the classical Krasovskii theorem, as well as linear eigenvalue analysis. A central feature is that convergence and limit behavior are in a sense treated separately, leading to significant conceptual simplifications. We establish new combination properties of nonlinear dynamic systems and use them to derive simple controller and observer designs for mechanical systems such as aircraft, underwater vehicles, and robots. The method is also applied to chemical chain reactions and mixture processes. The relative simplicity of these designs stems from their effective exploitation of the systems' structural specificities. Next, we analyze and quantify the global stability properties of physical partial differential equations such as the heat equation, or the Schroedinger equation. Lyapunov exponents are not coordinate-invariant, and thus their exact physical meaning is somewhat questionable. As an alternative, we suggest an extension of linear eigenvalue analysis to nonlinear dynamic systems. Finally, the thesis derives new controller and observer designs for general nonlinear dynamic systems. In particular, an extension of feedback linearization is proposed when the corresponding integrability conditions are violated.
by Winfried Stefan Lohmiller.
Ph.D.

APA, Harvard, Vancouver, ISO, and other styles

8

Cates, Andrew Thomas. "Nonlinear diffractive acoustics." Thesis, University of Cambridge, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.315809.

Full text

APA, Harvard, Vancouver, ISO, and other styles

9

Ziegler, Edward H. "Nonlinear system identification /." Online version of thesis, 1994. http://hdl.handle.net/1850/11583.

Full text

APA, Harvard, Vancouver, ISO, and other styles

10

Li, Jay-Shake. "Nonlinear dynamical analysis of operant behavior." [S.l. : s.n.], 2003. http://deposit.ddb.de/cgi-bin/dokserv?idn=96853032X.

Full text

APA, Harvard, Vancouver, ISO, and other styles

11

Izzuddin, Bassam Afif. "Nonlinear dynamic analysis of framed structures." Thesis, Imperial College London, 1990. http://hdl.handle.net/10044/1/8080.

Full text

APA, Harvard, Vancouver, ISO, and other styles

12

Sulieman, Hana. "Parametric sensitivity analysis in nonlinear regression." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape15/PQDD_0004/NQ27858.pdf.

Full text

APA, Harvard, Vancouver, ISO, and other styles

13

Ghadimi, R. "Nonlinear dynamic analysis of offshore structures." Thesis, Cranfield University, 1986. http://hdl.handle.net/1826/3581.

Full text

Abstract:

In this thesis consideration is given to a selection of nonlinear dynamic problems in the field of offshore engineering. Hydrodynamic loading on fixed horizontal and vertical tubular members and the dynamic response of articulated towers together with the distribution of shear force and bending moment along the tower are investigated using various wave theories. Effects of nonlinear convective acceleration terms in the calculation of fluid inertia forces and moments are examined and attention is given to integration of wave forces up to the free surface for vertical members. Calculation of fluid loading at the displaced position of the articulated tower and any Mathieu type instabilities that may occur have been considered. The dynamic analysis of a damaged Single Anchor Leg Storage (SALS) system subject to loss of buoyancy in the yoke chamber is studied. The equations of motion of the yoke/riser system are derived assuming large displacements and solved in the time domain. Time histories of the response, variations of the riser tension, velocities of riser top end and the time histories of pivot reactions are given. Natural periods and mode shapes for small displacements of the system are calculated. Two methods of simulating random seas, both represented by a sum of harmonic wave components, are used to simulate second order low frequency (slow drift) force on a tanker in head seas by Pinkster's time domain method. In one method the wave amplitudes are generated randomly from a Rayleigh distribution and in the other they are obtained deterministically via the wave spectrum. Time histories of slow drift force and response together with simulation results with various duration lengths are presented and compared. Estimates of the extreme vessel response and its relation to rms value are compared with the result of a commonly used method of determining peak/rms ratios. The results of these investigations highlight the importance of accurately simulating nonlinear effects in both fixed, floating and compliant offshore structures from the point of view of safe design and operation of such- systems.

APA, Harvard, Vancouver, ISO, and other styles

14

黃玉平 and Yuping Huang. "Nonlinear analysis of reinforced concrete structures." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1993. http://hub.hku.hk/bib/B31233090.

Full text

APA, Harvard, Vancouver, ISO, and other styles

15

Manktelow, Kevin Lee. "Dispersion analysis of nonlinear periodic structures." Diss., Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/51936.

Full text

Abstract:

The present research is concerned with developing analysis methods for analyzing and exploring finite-amplitude elastic wave propagation through periodic media. Periodic arrangements of materials with high acoustic impedance contrasts can be employed to control wave propagation. These systems are often termed phononic crystals or metamaterials, depending on the specific design and purpose. Design of these systems usually relies on computation and analysis of dispersion band structures which contain information about wave propagation speed and direction. The location and influence of complete (and partial) band gaps is a particularly interesting characteristic. Wave propagation is prohibited for frequencies that correspond to band gaps; thus, periodic systems behave as filters, wave guides, and lenses at certain frequencies. Controlling these behaviors has typically been limited to the manufacturing stage or the application of external stimuli to distort material configurations. The inclusion of nonlinear elements in periodic unit cells offers an option for passive tuning of the dispersion band structure through amplitude-dependence. Hence, dispersion analysis methods which may be utilized in the design of nonlinear phononic crystals and metamaterials are required. The approach taken herein utilizes Bloch wave-based perturbation analysis methods for obtaining closed-form expressions for dispersion amplitude-dependence. The influence of material and geometric nonlinearities on the dispersion relationship is investigated. It is shown that dispersion shifts result from both self-action (monochromatic excitation) and wave-interaction (multi-frequency excitation), the latter enabling dynamic anisotropy in periodic media. A particularly novel aspect of this work is the ease with which band structures of discretized systems may be analyzed. This connection enables topology optimization of unit cells with nonlinear elements. Several important periodic systems are considered including monoatomic lattices, multilayer materials, and plane stress matrix-inclusion configurations. The analysis methods are further developed into a procedure which can be implemented numerically with existing finite-element analysis software for analyzing geometrically-complex materials.

APA, Harvard, Vancouver, ISO, and other styles

16

Gifford, Stephen John. "Volterra series analysis of nonlinear structures." Thesis, Heriot-Watt University, 1989. http://hdl.handle.net/10399/939.

Full text

APA, Harvard, Vancouver, ISO, and other styles

17

Johnson, Sam. "Analysis of nonlinear dynamic physiological systems." Thesis, University of Newcastle Upon Tyne, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.433132.

Full text

APA, Harvard, Vancouver, ISO, and other styles

18

Karbassi, A. A. "Nonlinear response analysis of guyed masts." Thesis, University of Westminster, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.376451.

Full text

APA, Harvard, Vancouver, ISO, and other styles

19

Slawik, Alexander John. "Nonlinear Analysis of Silicon Microdisk Resonators." Thesis, Northwestern University, 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=3741327.

Full text

Abstract:

This dissertation addresses the character, control, and application of self-sustained oscillations in two-photon absorption dominated optical cavities. The complex interactions of photons, electrons, and thermal effects are understood to drive these emergent oscillations, with the dynamics captured by a system of ordinary differential equations. First, I explore the dynamics of the model and characterize the emergent optical oscillations as relaxation oscillations of a fast-slow system under certain conditions. Within this framework, I establish the entrainment of the oscillations to periodic forcing, providing an easy mechanism for control. The model is further extended to an opto-mechanical system which can be used as a sensor for atomic force microscopy. Analysis of the system predicts that two-photon absorption based effects can excite the mechanical modes of the sensor and increase the signal to noise ratio of the optical readout.

APA, Harvard, Vancouver, ISO, and other styles

20

Leeuwrik, Maarten James. "Nonlinear vibration analysis of inflatable dams." Thesis, Virginia Tech, 1987. http://hdl.handle.net/10919/45786.

Full text

Abstract:

In recent years the use of inflatable dams has become more widespread throughout the world. Various people have done studies on the shape and membrane tension of these structures; however, only a few authors have considered dynamic behavior. Due to the nature of the applications and the material composition of these structures, a study considering the dynamic response of an inflatable dam is warranted.

In this study, the equation of motion for an air-inflated dam is derived, then solved using the Galerkin approximation method. The solution is performed for a one-term approximation and a two-term approximation, where both solutions use a sine function to approximate the deflected shape of the dam. Frequencies and amplitudes are calculated and presented in tables and plots for the first four modes, and three different values of the central angle of the dam. Comparisons to the results of other studies are presented at the conclusion of this study.
Master of Science

APA, Harvard, Vancouver, ISO, and other styles

21

Battista, Antonio. "An analysis of nonlinear thin structures." Thesis, La Rochelle, 2019. http://www.theses.fr/2019LAROS017.

Full text

Abstract:

Le thème principal de cette thèse est l'étude du comportement mécanique de structures minces élancées dans le domaine non-linéaire. Ce travail de thèse est présenté sous la forme d’une collection d’articles publiés au cours du doctorat et est divisé en deux parties. La première partie concerne l’analyse de modèles non-linéaires de poutres inextensibles et extensibles, généralisant sur différents aspects les modèles de poutres d’Euler et de Timoshenko. Une étude théorique de l’existence et de l’unicité de solutions est complétée de simulations numériques mettant en évidence l’existence de solutions multiples avec l’augmentation de la force appliquée. Une étude numérique de la multiplicité de solutions d’un modèle de poutre extensible en grands déplacements est également effectuée. La deuxième partie concerne la justification formelle par méthodes asymptotiques d’un modèle de membrane original présentant une multiplicité de solutions pour des chargements particuliers, pouvant modéliser les plissements de certaines structures très minces sollicitées en cisaillement
The main theme of this thesis is the study of the mechanical behavior of thin slender structures in the nonlinear domain. This thesis work is presented in the form of a collection of articles published during the Ph.D. and is divided into two parts. The first part deals with the analysis of nonlinear models of inextensible and extensible beams, generalizing on different aspects the beam models of Euler and Timoshenko. A theoretical study of the existence and uniqueness of solutions is completed by numerical simulations highlighting the existence of multiple solutions with the increase of the applied force. A numerical study of the multiplicity of solutions of an extensible beam model in large displacements is also carried out. The second part concerns the formal justification by asymptotic methods of an original membrane model presenting a multiplicity of solutions for particular loads, able to model the wrinkling of some very thin structures with a shear stress applied

APA, Harvard, Vancouver, ISO, and other styles

22

Michel, Jonathan R. "Essays in Nonlinear Time Series Analysis." The Ohio State University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu1555001297904158.

Full text

APA, Harvard, Vancouver, ISO, and other styles

23

Huang, Yuping. "Nonlinear analysis of reinforced concrete structures /." [Hong Kong] : University of Hong Kong, 1993. http://sunzi.lib.hku.hk/hkuto/record.jsp?B13458917.

Full text

APA, Harvard, Vancouver, ISO, and other styles

24

Douglas, Robert. "Rearrangements and nonlinear analysis of vortices." Thesis, University of Bath, 1992. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.317338.

Full text

APA, Harvard, Vancouver, ISO, and other styles

25

Peske, Wendy Ann. "A topological approach to nonlinear analysis." CSUSB ScholarWorks, 2005. https://scholarworks.lib.csusb.edu/etd-project/2779.

Full text

Abstract:

A topological approach to nonlinear analysis allows for strikingly beautiful proofs and simplified calculations. This topological approach employs many of the ideas of continuous topology, including convergence, compactness, metrization, complete metric spaces, uniform spaces and function spaces. This thesis illustrates using the topological approach in proving the Cauchy-Peano Existence theorem. The topological proof utilizes the ideas of complete metric spaces, Ascoli-Arzela theorem, topological properties in Euclidean n-space and normed linear spaces, and the extension of Brouwer's fixed point theorem to Schauder's fixed point theorem, and Picard's theorem.

APA, Harvard, Vancouver, ISO, and other styles

26

ZANETTI, CHINI EMILIO. "Essays in nonlinear time series analysis." Doctoral thesis, Università degli Studi di Roma "Tor Vergata", 2013. http://hdl.handle.net/2108/203343.

Full text

Abstract:

This paper introduces a variant of the smooth transition autoregression (STAR).Theproposedmodelisabletoparametrizetheasymmetryinthetails of the transition equation by using a particular generalization of the logistic function. The null hypothesis of symmetric adjustment toward a new regime is tested by building two diﬀerent LM-type tests. The ﬁrst one maintains the original parametrization, while the second one is based on a third-order expanded auxiliary regression. Three diagnostic tests for no error autocorrelation, no additive asymmetry and parameter constancy are also discussed. The empirical size and power of the new symmetry as well as diagnostic tests are investigated by an extensive Monte Carlo experiment. An empirical application of the so generalized STAR (GSTAR) model to four economic time series reveals that the asymmetry in the transition between two regimes is a feature to be considered for economic analysi

APA, Harvard, Vancouver, ISO, and other styles

27

Teo, Sui-Guan. "Analysis of nonlinear sequences and streamciphers." Thesis, Queensland University of Technology, 2013. https://eprints.qut.edu.au/63358/1/Sui-Guan_Teo_Thesis.pdf.

Full text

Abstract:

Streamciphers are common cryptographic algorithms used to protect the confidentiality of frame-based communications like mobile phone conversations and Internet traffic. Streamciphers are ideal cryptographic algorithms to encrypt these types of traffic as they have the potential to encrypt them quickly and securely, and have low error propagation. The main objective of this thesis is to determine whether structural features of keystream generators affect the security provided by stream ciphers.These structural features pertain to the state-update and output functions used in keystream generators. Using linear sequences as keystream to encrypt messages is known to be insecure. Modern keystream generators use nonlinear sequences as keystream.The nonlinearity can be introduced through a keystream generator's state-update function, output function, or both. The first contribution of this thesis relates to nonlinear sequences produced by the well-known Trivium stream cipher. Trivium is one of the stream ciphers selected in a final portfolio resulting from a multi-year project in Europe called the ecrypt project. Trivium's structural simplicity makes it a popular cipher to cryptanalyse, but to date, there are no attacks in the public literature which are faster than exhaustive keysearch. Algebraic analyses are performed on the Trivium stream cipher, which uses a nonlinear state-update and linear output function to produce keystream. Two algebraic investigations are performed: an examination of the sliding property in the initialisation process and algebraic analyses of Trivium-like streamciphers using a combination of the algebraic techniques previously applied separately by Berbain et al. and Raddum. For certain iterations of Trivium's state-update function, we examine the sets of slid pairs, looking particularly to form chains of slid pairs. No chains exist for a small number of iterations.This has implications for the period of keystreams produced by Trivium. Secondly, using our combination of the methods of Berbain et al. and Raddum, we analysed Trivium-like ciphers and improved on previous on previous analysis with regards to forming systems of equations on these ciphers. Using these new systems of equations, we were able to successfully recover the initial state of Bivium-A.The attack complexity for Bivium-B and Trivium were, however, worse than exhaustive keysearch. We also show that the selection of stages which are used as input to the output function and the size of registers which are used in the construction of the system of equations affect the success of the attack. The second contribution of this thesis is the examination of state convergence. State convergence is an undesirable characteristic in keystream generators for stream ciphers, as it implies that the effective session key size of the stream cipher is smaller than the designers intended. We identify methods which can be used to detect state convergence. As a case study, theMixer streamcipher, which uses nonlinear state-update and output functions to produce keystream, is analysed. Mixer is found to suffer from state convergence as the state-update function used in its initialisation process is not one-to-one. A discussion of several other streamciphers which are known to suffer from state convergence is given. From our analysis of these stream ciphers, three mechanisms which can cause state convergence are identified.The effect state convergence can have on stream cipher cryptanalysis is examined. We show that state convergence can have a positive effect if the goal of the attacker is to recover the initial state of the keystream generator. The third contribution of this thesis is the examination of the distributions of bit patterns in the sequences produced by nonlinear filter generators (NLFGs) and linearly filtered nonlinear feedback shift registers. We show that the selection of stages used as input to a keystream generator's output function can affect the distribution of bit patterns in sequences produced by these keystreamgenerators, and that the effect differs for nonlinear filter generators and linearly filtered nonlinear feedback shift registers. In the case of NLFGs, the keystream sequences produced when the output functions take inputs from consecutive register stages are less uniform than sequences produced by NLFGs whose output functions take inputs from unevenly spaced register stages. The opposite is true for keystream sequences produced by linearly filtered nonlinear feedback shift registers.

APA, Harvard, Vancouver, ISO, and other styles

28

Chan, Gordon. "Nonlinear Analysis of Multistory Structures Using "NONLIN"." Thesis, Virginia Tech, 2005. http://hdl.handle.net/10919/31430.

Full text

Abstract:

During the months I have been at Virginia Tech, I have experienced the most exciting time of my life. There are many persons who helped me to pursue my Masterâ s degree. I would like to take this opportunity to express my appreciations to them. I would like to thank my advisor and committee chairman, Dr Finley A. Charney. He has supported me for the entire duration of this project with all of his efforts. Without his assistance, it would have been very difficult for me to learn so many concepts in the field of nonlinear dynamic analysis and practical earthquake engineering. I would also like to acknowledge my other committee members, Dr. Raymond Plaut and Dr. W. Samuel Easterling, for taking the time to review the thesis and providing valuable insights and feedback on this thesis. I would like to thank my father, Chan Kwok Fung, who encouraged me to pursue my Master Degree, and my mother, Yu Yuk Ping, who brought me to life. I would like to thank my sister, Doris Chan, and my girlfriend, Ka Man Chan, for supporting and encouraging me during the past two years at Virginia Tech. Finally, I would like to give thanks to the rest of my family, friends, professors, and fellow graduate students for their help and encouragement during my stay at Virginia Tech.
Master of Science

APA, Harvard, Vancouver, ISO, and other styles

29

Kabir, Ahsanul. "Nonlinear analysis of reinforced concrete structural slabs." Thesis, University of Strathclyde, 1986. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=21467.

Full text

Abstract:

Nonlinear response of a structure to progressive loading may originate from two different sources viz, geometric nonlinearity and material nonlinear behaviour. For a rationally proportioned concrete structure, the material nonlinear responses are believed to contribute the major part of its total nonlinear behaviour. Geometric nonlinearities, become significant only when the structure is relatively slender. It is the material nonlinearities of reinforced concrete structures that are of interest in this investigation. Two plate bending finite elements have been generalised to include coupling of inplane actions with the bending effects. This was achieved through layering concept. One of these elements had been employed by some previous researchers. But the present formulation is different from theirs in that a numerical integration scheme is introduced to evaluate the stiffnesses and internal equivalent forces. A number of schemes for solving the nonlinear equations have been included in the present formulation. Suitability and effectiveness of these schemes in tracing the material nonlinear responses of concrete slabs have been examined. The numerical material model behaviour is based on the experimental observation reported by various authors. Readily available material characteristic properties are used in the description of the model. The overall response of reinforced concrete slabs is found to be significantly influenced by the cracking and post cracking treatment of concrete. Some form of tension stiffening scheme seems necessary to represent the structural response realistically. A number of conventional tension stiffening schemes have been incorporated, including a simple alternative formulation. The effect of different tension stiffening schemes and some other numerical parameters on the numerical solution of concrete structures have been investigated. Laboratory tests were carried out on a number of square and rectangular model slabs. The supporting arrangement and the applied loading systems were the main variables. These experimental records were later compared with the numerical predictions. Some other test results from literature have been included also.

APA, Harvard, Vancouver, ISO, and other styles

30

Lans, Ivo A. van der. "Nonlinear multivariate analysis for multiattribute preference data." [Leiden] : DSWO Press, Leiden University, 1992. http://catalog.hathitrust.org/api/volumes/oclc/28733326.html.

Full text

APA, Harvard, Vancouver, ISO, and other styles

31

Prabhakaran, Usha. "Nonlinear analysis of scaffolds with semirigid connections." Thesis, Oxford Brookes University, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.515216.

Full text

APA, Harvard, Vancouver, ISO, and other styles

32

Janzen, Walter F. "Cable stayed bridges : nonlinear elastic dimensional analysis." Thesis, University of British Columbia, 1988. http://hdl.handle.net/2429/28388.

Full text

Abstract:

Cable stayed bridges are the state of the art in long span bridges. Developments in cable response analysis and computer hardware and software have allowed engineers to design and build many cable stayed bridges. Bridges of many different configurations with longer and longer spans are being built. With the long spans and high axial loads in the deck, the stability of cable stayed bridges becomes a growing concern. Current analysis procedures use a parabolic approximation to the true catenary response of cables, which is quite accurate for tight cables; however, for near instability conditions with the accompanying large deflections and consequently loose cables, a catenary model is called for. Herein, a study is conducted on the elastic stability of cable stayed bridges utilizing a true catenary model of cable response. A dimensional analysis of cable stayed bridge stability is undertaken as well as deck maximum deflection and moment under service load conditions. A computer program written by this author is the analysis tool used in this work. The program is given the acronym ULA which stands for Ultimate Load Analysis. ULA is a nonlinear plane frame program with catenary cable elements and an interactive graphics interface. The dimensional analysis is carried out by comparing the computer model of a cable stayed bridge to the theoretical model of a beam on an elastic foundation. Two preliminary simplified cable stayed bridge backspan models are studied first in order to develop the dimensionless ratios that are applicable to the bridge response and to gain an insight into the cable stayed bridge behaviour. The final model is that of an entire cable stayed bridge. Because of the multitude of parameters governing cable stayed bridge behaviour it is not possible to describe all cable stayed bridges. Instead, the dimensionless behaviour of a standard model is examined and the sensitivity of this standard to various parameter variations is given in the form of dimensionless charts. Finally, a preliminary design and analysis aid is developed from the dimensionless charts and is then applied to two existing bridge designs.
Applied Science, Faculty of
Civil Engineering, Department of
Graduate

APA, Harvard, Vancouver, ISO, and other styles

33

Monahan, Adam Hugh. "Nonlinear principal component analysis of climate data." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp02/NQ48678.pdf.

Full text

APA, Harvard, Vancouver, ISO, and other styles

34

Barrowman, Nicholas J. "Nonlinear mixed effects models for meta-analysis." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp02/NQ57342.pdf.

Full text

APA, Harvard, Vancouver, ISO, and other styles

35

Iyoho, Anthony E. "Modeling and analysis of nonlinear biological systems." Diss., Columbia, Mo. : University of Missouri-Columbia, 2007. http://hdl.handle.net/10355/6012.

Full text

Abstract:

Thesis (Ph. D.)--University of Missouri-Columbia, 2007.
The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on December 28, 2007) Includes bibliographical references.

APA, Harvard, Vancouver, ISO, and other styles

36

El-Adas, Kadmous Moufid. "Linear and nonlinear buckling analysis via ABAQUS." Master's thesis, This resource online, 1990. http://scholar.lib.vt.edu/theses/available/etd-01262010-020017/.

Full text

APA, Harvard, Vancouver, ISO, and other styles

37

Carvalho, Renato de Souza. "Nonlinear regression application to well test analysis /." Access abstract and link to full text, 1993. http://0-wwwlib.umi.com.library.utulsa.edu/dissertations/fullcit/9416602.

Full text

APA, Harvard, Vancouver, ISO, and other styles

38

Ciftci, Guclu Koray. "Nonlinear Analysis Of Reinforced Concrete Frame Structures." Master's thesis, METU, 2013. http://etd.lib.metu.edu.tr/upload/12615549/index.pdf.

Full text

Abstract:

Reinforced concrete frames display nonlinear behavior both due to its composite nature and the material properties of concrete itself. The yielding of the reinforcement, the non-uniform distribution of aggregates and the development of cracks under loading are the main reasons of nonlinearity. The stiffness of a frame element depends on the combination of the modulus of elasticity and the geometric properties of its section - area and the moment of inertia. In practice, the elastic modulus is assumed to be constant throughout the element and the sectional properties are assumed to remain constant under loading. In this study, it is assumed that the material elasticity depends on the reinforcement ratio and its distribution over the section. Also, the cracks developing in the frame element reduces the sectional properties. In case of linear analysis, the material and sectional parameters are assumed to be constant. In practice, the modulus of elasticity E is a predefined value based on previous experiments and the moment of inertia I is assumed to be constant throughout the analysis. However, in this study, E and I are assumed to be combined. In other words, they cannot be separated from each other throughout the analysis. These two parameters are handled as a single parameter as EI . This parameter is controlled by the reinforcement ratio and its configuration, sectional properties and deformation of the member. Two types of analysis, namely a sectional and a finite element analyses, are used in this study. From the sectional analysis, the parameter EI is calculated based on the sectional geometry, material properties and the axial load applied on the section. The parameter EI is then used in the finite element analysis to calculate the sectional forces and the nodal displacements. For the nonlinear analysis, the Newton-Raphson iterative approach is followed until convergence is obtained.

APA, Harvard, Vancouver, ISO, and other styles

39

Park, Joonam. "A visualization system for nonlinear frame analysis." Thesis, Georgia Institute of Technology, 1999. http://hdl.handle.net/1853/19172.

Full text

APA, Harvard, Vancouver, ISO, and other styles

40

Tannir, Dani A. "Efficient nonlinear distortion analysis of RF circuits." Thesis, McGill University, 2006. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=99541.

Full text

Abstract:

The third order intercept point (IP3) is an important figure of merit which gives a measure of the linearity of communication circuits. There are two classes of methods for calculating the IP3 of a circuit. The first is analytical and is usually based on Volterra series. This approach is cumbersome and is difficult to apply to arbitrary circuits with arbitrary non-linearities. The second class of methods is based on multi-tone simulations and is general and flexible but requires significant CPU cost. In this thesis a new method based on the computation of the circuit moments is proposed. The new approach uses the circuit moments in order to numerically compute the Volterra kernels. This automates the process of numerically obtaining such kernels for any circuit and results in an efficient approach for the computation of IP3 for arbitrary circuits. The proposed approach is simple to apply and presents a significant improvement in CPU cost over existing methods.

APA, Harvard, Vancouver, ISO, and other styles

41

Dussault, Serge. "Nonlinear seismic analysis using vector superposition methods." Thesis, McGill University, 1991. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=60575.

Full text

Abstract:

This thesis presents two algorithms to solve nonlinear seismic problems in generalized coordinates, one that uses a set of vectors computed from initial properties, the Pseudo-Force Method (PFM), and another that continuously updates the vector basis to represent the nonlinear behaviour, the Tangent Spectrum Method (TSM). Both methods can use either exact eigenvectors or load dependent vectors as vector basis. Parametric analyses are carried out on a series of multistory buildings idealized as shear beam structures with bilinear hysteretic behaviour. The effects of the truncation of the vector basis on the stability and the quality of the nonlinear solutions are investigated using nonlinear response parameters such as ductility, energy balance, and dissipation. The algorithms are then used to make a comparative study on the effects of different mathematical representations of viscous damping based either on initial elastic, or tangent modal, properties of MDOF structures.
For a flexible 25-story structure, the solution is much more sensitive to the truncation of the vector basis when the PFM is used instead of the TSM.

APA, Harvard, Vancouver, ISO, and other styles

42

Clarke, Liam. "Nonlinear time series analysis of data streams." Thesis, University of Oxford, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.401147.

Full text

APA, Harvard, Vancouver, ISO, and other styles

43

Zolghadr, Zadeh Jahromi Hamid. "Partitioned analysis of nonlinear soil-structure interaction." Thesis, Imperial College London, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.512070.

Full text

APA, Harvard, Vancouver, ISO, and other styles

44

Jiang, Jian. "Nonlinear thermomechanical analysis of structures using OpenSees." Thesis, University of Edinburgh, 2013. http://hdl.handle.net/1842/7749.

Full text

Abstract:

The behaviour of heated structures is strongly governed by thermal induced deformation and degradation of material properties. This thesis presents an augmentation of the software framework OpenSees to enable thermomechanical analysis of structures. The developments contributed to OpenSees are tested by series of benchmark cases and experimental results. OpenSees is an object-oriented, open source software framework developed at UC Berekeley for providing an advanced computational tool to simulate non-linear response of structural frames to earthquakes. OpenSees was chosen to be extended to enable the modelling of structures in fire. The development of this capability involved creating new thermal load classes to define the temperature distribution in structural members and modifying existing material classes to include temperature dependent properties according to Eurocodes. New functions were also added into the existing corotational beam/column element (2D and 3D) to apply temperature related loads. A new geometrically nonlinear shell element was created (based on the existing linear MITC4 shell element in OpenSees) using total Lagrangian formulation. Appropriate thermal load, material and section classes were also developed for enabling thermomechanical analysis using the nonlinear shell element. A number of benchmark tests were carried out to verify the performance of the new developments implemented in OpenSees. The benchmark tests involved subjecting beams and plates to a range of through depth temperature gradients with OpenSees results compared against closed form solutions. Further verification was also carried out by comparing OpenSees results with ABAQUS results. The extended OpenSees framework was also used to model experiments such as two plane steel frames at elevated temperatures, the Cardington Restrained Beam Test and the Cardington Corner Test and an earthquake damaged reinforced concrete (RC) frame subjected to a subsequent fire. The existing DruckerPrager material class in OpenSees was used to the model concrete in the composite floor in the Cardington tests and in the RC frame. The pinching material available in OpenSees was used to model the beams and columns in the RC frame to consider the cyclic degradation of strength and stiffness during the increasing cyclic displacements imposed on the RC frame before the fire. In all cases the results from OpenSees show good agreement with test data.

APA, Harvard, Vancouver, ISO, and other styles

45

Veltz, Romain, and Romain Veltz. "Nonlinear analysis methods in neural field models." Phd thesis, Université Paris-Est, 2011. http://tel.archives-ouvertes.fr/tel-00686695.

Full text

Abstract:

This thesis deals with mesoscopic models of cortex called neural fields. The neural field equations describe the activity of neuronal populations, with common anatomical / functional properties. They were introduced in the 1950s and are called the equations of Wilson and Cowan. Mathematically, they consist of integro-differential equations with delays, the delays modeling the signal propagation and the passage of signals across synapses and the dendritic tree. In the first part, we recall the biology necessary to understand this thesis and derive the main equations. Then, we study these equations with the theory of dynamical systems by characterizing their equilibrium points and dynamics in the second part. In the third part, we study these delayed equations in general by giving formulas for the bifurcation diagrams, by proving a center manifold theorem, and by calculating the principal normal forms. We apply these results to one-dimensional neural fields which allows a detailed study of the dynamics. Finally, in the last part, we study three models of visual cortex. The first two models are from the literature and describe respectively a hypercolumn, i.e. the basic element of the first visual area (V1) and a network of such hypercolumns. The latest model is a new model of V1 which generalizes the two previous models while allowing a detailed study of specific effects of delays

APA, Harvard, Vancouver, ISO, and other styles

46

Cox, Wilfred. "Nonlinear analysis of reinforced concrete portal frames." Thesis, University of East London, 2001. http://roar.uel.ac.uk/1303/.

Full text

Abstract:

There are considerable difficulties in describing the properties of reinforced concrete materials and their interaction. It is therefore necessary to calibrate the mathematical model by accurate testing of laboratory specimens. It can be shown that momentcurvature relationship varies along the length of a member and at beam-column joints. This behaviour depends critically on the geometry of the joint, reinforcement details and the stress-strain characteristics of concrete and steel. Tests have been carried out on model reinforced concrete portal frames and independent specimens making up the frame to predict their non-linear behaviour. The stiffness of the joint plays an important role in the response of the complete frame structure. The behaviour of the corner joints is of particular interest because both the strength and ductility differs for opening and closing joints. The loss of stiffness at joints has a significant effect on the inelastic deformations. The non-linear finite element (FE) program developed takes into account the loss of stiffness at joints and the falling branch behaviour of the material stress-strain relationships. Constant, linear, and parabolic variation in flexural rigidity (EI) and axial rigidity (EA) are taken into consideration along the element length. The combined effect of material and geometric non-linearity is considered. The FE program may use either calculated momentcurvature relationship of different elements or the experimental data obtained from tests. The results show good agreement between the theoretical and experimental beam moment-curvature relationships. Horizontally loaded frame analysis, which involves opening and closing joints, shows that ignoring the joint effect over-estimates the strength. In the case of vertically loaded frames, which involves two closing joints, ignoring the joint effects had little or no influence. The results show good agreement between the theoretical and experimental frame force-displacement relationships throughout the loading range providing the change of stiffness at joints is taken into account for horizontally loaded frames.

APA, Harvard, Vancouver, ISO, and other styles

47

Shen, Che-Chou, and 沈哲州. "ultrsonic nonlinear imaging analysis." Thesis, 2000. http://ndltd.ncl.edu.tw/handle/24394853479497817563.

Full text

Abstract:

碩士
國立臺灣大學
電機工程學研究所
88
Performance issues related to tissue harmonic imaging are discussed in this thesis. Tissue harmonic signal is generated due to finite amplitude distortion as sound waves propagate through the body. The intensity of harmonic is low in the near field, thus limiting sensitivity and penetration of tissue harmonic imaging. A multiple transmit focusing approach has been proposed to overcome the problem. In addition to the primary focus, a secondary focus is added to increase harmonic generation. Using both simulations and experiments, it is shown that the near-field harmonic intensity increases by the addition of the secondary focus. However, adding a secondary focus also results in elevated sidelobes. This degrades contrast resolution in the harmonic image. Nevertheless, contrast resolution is still improved over conventional fundamental imaging. Effects of harmonic leakage on image quality were also addressed. Harmonic leakage is often present since the transmitted signal may contain harmonics induced by the imaging system. The leaked harmonic signal has different beam-forming characteristics from those of tissue harmonics. It is shown that harmonic leakage degrades contrast resolution of tissue harmonic imaging. We compared effects of various transmit signals for their leakage using both simulations and experiments. Impact of system nonlinearity was also studied using hydrophone beam pattern measurements.

APA, Harvard, Vancouver, ISO, and other styles

48

Lin, Yen-Cherng, and 林炎成. "Topics in Nonlinear Analysis." Thesis, 2000. http://ndltd.ncl.edu.tw/handle/87673884325880049413.

Full text

Abstract:

博士
國立中山大學
應用數學系
88
Some new coincidence theorems on more abstract nonlinear paces, the G-convex space, are introduced. These new formulations enlarge the class of the problems that have been discussed in the literature. We give some applications of these new coincidence theorems to the related topics, such as the general KKM theorems, the abstract variational inequalities, the matching theorem, the generalized implicit vector variational problems,the fixed point theorems, etc. A new class of G-maps is introduced. We employ these new results to construct more generalized coincidence theorems and the related problems. We also consider some new S-KKM and intersection theorems.

APA, Harvard, Vancouver, ISO, and other styles

49

Yu, Wei. "Variance Analysis for Nonlinear Systems." 2007. http://hdl.handle.net/1974/878.

Full text

Abstract:

In the past decades there has been onsiderable commercial and academic interest in methods for monitoring control system performance for linear systems. Far less has been written on control system performance for nonlinear dynamic / stochastic systems. This thesis presents research results on three control performance monitoring topics for the nonlinear systems: i) Controller assessment of a class of nonlinear systems: The use of autoregressive moving average (ARMA) models to assess the control loop performance for linear systems is well known. Classes of nonlinear dynamic / stochastic systems for which a similar result can be obtained are established for SISO discrete systems. For these systems, the performance lower bounds can be estimated from closed-loop routine operating data using nonlinear autoregressive moving average with exogenous inputs (NARMAX) models. ii) Variance decomposition of nonlinear systems / time series: We develop a variance decomposition approach to quantify the effects of different sources of disturbances on the nonlinear dynamic / stochastic systems. A method, called ANOVA-like decomposition, is employed to achieve this variance decomposition. Modifications of ANOVA-like decomposition are proposed so that the NOVA-like decomposition can be used to deal with the time dependency and the initial condition. iii) Parameter uncertainty effects on the variance decomposition: For the variance decomposition in the second part, the model parameters are assumed to be exactly known. However, parameters of empirical or mechanistic models are uncertain. The uncertainties associated with parameters should be included when the model is used for variance analysis. General solutions of the parameter uncertainty effects on the variance decomposition for the general nonlinear systems are proposed. Analytical solutions of the parameter uncertainty effects on the variance decomposition are provided for models with linear parameters.
Thesis (Ph.D, Chemical Engineering) -- Queen's University, 2007-10-17 16:02:26.376
This work was sponsored by NSERC Discovery, NSERC Equipment, Shell Global Solutions, OGSST and QGA

APA, Harvard, Vancouver, ISO, and other styles

50

鄭煜群. "Analysis on Mechanical Nonlinear System." Thesis, 1997. http://ndltd.ncl.edu.tw/handle/21072619335496133589.

Full text

Abstract:

碩士
中原大學
機械工程學系
85
This study investigates the dynamics of a single degree of freedom (SDOF) wire in a winding machine. This system has piecewise-linear stiffness and is subjected to a forcing excitation due to imbalance and a parametric excitation due to tension. The frequencies of both parametric and foreing excitations are not equal or do not have a ratio of two simple integers. Using the fourth-order Runge-Kutta method and introducing a J integral, this strongly nonlinear system can be estimated for various parameters. Then, the mode-locking motions, main resonant intervals, and subharmonic modes can be found. Also, all possible combined subharmonic and superharmonic motions and routes to chaos are observed by J-bifurcation illustrations with the assistance of Poincare maps, phase portraits, response waveforms, frequency spectra, and Lyapunov exponents. Thus, the physical illustrations of such a system can provide stabilization by appropriate design parameters.

APA, Harvard, Vancouver, ISO, and other styles

Dissertations / Theses on the topic 'Nonlinear analysis'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles