Dissertations / Theses: 'Mathematical analysis'

1

Karlström, Viktor. "Mathematical analysis of options." Thesis, KTH, Farkost och flyg, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-43834.

Full text

APA, Harvard, Vancouver, ISO, and other styles

2

Khalo, Xolani. "Analysis of grade 10 mathematical literacy students’ errors in financial mathematics." Thesis, University of Fort Hare, 2014. http://hdl.handle.net/10353/1369.

Full text

Abstract:

The main aim of the study was (1) to identify errors committed by learners in financial mathematics and (2) to understand why learners continue to make such errors so that mechanisms to avoid such errors could be devised. The following has been hypothesised; (1) errors committed by learners are not impact upon by language difficulties, (2) errors committed by learners in financial mathematics are not due to prerequisite skills, facts and concepts, (3) errors committed by learners in financial mathematics are not due to the application of irrelevant rules and strategies. Having used Polya’s problem-solving techniques, Threshold Concept and Newman’s Error Analysis as the theoretical frameworks for the study, a four-point Likert scale and three content-based structured-interview questionnaires were developed to address the research questions. The study was conducted by means of a case study guided by the positivists’ paradigm where the research sample comprised of 105 Grade-10 Mathematics Literacy learners as respondents. Four sets of structured-interview questionnaires were used for collecting data, aimed at addressing the main objective of the study. In order to test the reliability and consistency of the questionnaires for this study, Cronbach’s Alpha was calculated for standardised items (α = 0.705). Content analysis and correlation analysis were employed to analyse the data. The three hypotheses of this study were tested using the ANOVA test and hence revealed that, (1) errors committed by learners in financial mathematics are not due to language difficulties, as all the variables illustrated a statistical non-significance (2) errors committed by learners in financial mathematics are not due to prerequisite skills, facts and concepts, as the majority of the variables showed non-significance and (3) errors committed by learners in financial mathematics were due to the application of irrelevant rules and strategies, as 66.7% of the variables illustrated a statistical significance to the related research question.

APA, Harvard, Vancouver, ISO, and other styles

3

Wilmer, Archie. "Javelin analysis using mathematical modeling." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1994. http://handle.dtic.mil/100.2/ADA283466.

Full text

Abstract:

Thesis (M.S. in Applied Mathematics) Naval Postgraduate School, June 1994.
Thesis advisor(s): Bard K. Mansager, Maurice D. Weir. "June 1994." Includes bibliographical references. Also available online.

APA, Harvard, Vancouver, ISO, and other styles

4

Bennett, James Cameron, and james bennett@student rmit edu au. "Mathematical Analysis of Film Blowing." RMIT University. Mathematical and Geospatial Sciences, 2008. http://adt.lib.rmit.edu.au/adt/public/adt-VIT20081128.115021.

Full text

Abstract:

Film blowing is a highly complex industrial process used to manufacture thin plastic films for uses in a wide range of applications; for example, plastic bags. The mathematical modelling of this process involves the analysis of highly nonlinear differential equations describing the complex phenomena arising in the film blowing process, and requires a sophisticated mathematical approach. This dissertation applies an innovative combination of tools, namely analytic, numerical and heuristic mathematical techniques to the analysis of the film blowing process. The research undertaken examines, in particular, a two-point boundary value problem arising from the modelling of the radial profile of the polymer film. For even the simplest modelling of this process, namely the isothermal Newtonian model, the resulting differential equation is a highly nonlinear, second order one, with an extra degree of difficulty due to the presence of a small parameter multiplying the highest derivative. Thus, the problem falls into the category of a nonlinear singular perturbation problem. Analytic techniques are applied to the isothermal Newtonian blown film model to obtain a closed form explicit approximation to the film bubble radius. This is then used as a base approximation for an iterative numerical scheme to obtain an improved numerical solution of the problem. The process is extended to include temperature variations, varying viscosity (Power law model) and viscoelastic effects (Maxwell model). As before, closed form approximations are constructed for these models which are used to launch numerical schemes, whose solutions display good accuracy. The results compare well with results obtained by purely numerical solutions in the literature.

APA, Harvard, Vancouver, ISO, and other styles

5

Ainslie-Malik, Gregory R. "Mathematical analysis of PWM processes." Thesis, University of Nottingham, 2013. http://eprints.nottingham.ac.uk/13021/.

Full text

Abstract:

Pulse width modulation (PWM) inverters convert a direct current (DC) power supply to an alternating current (AC) supply by means of high frequency switching between two DC sources. Undesirable high-frequency components are generated in the frequency spectra of the voltages and currents of PWM inverters. The high-frequency components are ultimately removed from the input and output waveforms by filters. PWM inverters are used in a wide variety of electrical devices, ranging from microwave ovens to the electrical parts of aircraft. In many of these devices, minimising the size and weight of the electrical parts is important, and, consequently, it is desirable to design efficient filters for PWM inverters. Identification of the unwanted high-frequency components allows for optimal filter design. In this thesis we use alternative methods to calculate the voltages and currents of PWM inverters. Mathematical models are developed for several PWM inverter designs, and Fourier analysis of the mathematical expressions for the currents and voltages allow us to determine frequency spectra. The methods used in this thesis are shown to be more suitable to the calculation of spectra for complex inverter designs, compared to conventional techniques. In particular, input current spectra are calculated for PWM inverters that incorporate dead time and space vector modulation (SVM) inverters for the first time here.

APA, Harvard, Vancouver, ISO, and other styles

6

Yoo, Kyung Hyun. "Image analysis using mathematical morphology." Thesis, Kansas State University, 1989. http://hdl.handle.net/2097/15232.

Full text

APA, Harvard, Vancouver, ISO, and other styles

7

Memon, Sohail Ahmed. "Mathematical modelling of complex dynamics." Thesis, University of Central Lancashire, 2017. http://clok.uclan.ac.uk/20497/.

Full text

Abstract:

Soft materials have a wide range of applications, which include the production of masks for nano–lithography, the separation of membranes with nano–pores, and the preparation of nano–size structures for electronic devices. Self–organization in soft matter is a primary mechanism for the formation of structure. Block copolymers are long chain molecules composed of several different polymer blocks covalently bonded into a single macromolecule, which belong to an important class of soft materials which can self–assemble into different nano–structures due to their natural ability to microphase separate. Experimental and theoretical studies of block copolymers are quite challenging and, without computer simulations, it is difficult and problematic to analyse modern experiments. The Cell Dynamics Simulation (CDS) technique is a fast and accurate computational technique, which has been used to investigate block copolymers. The stability has been analysed by making use of different discrete Laplacian operators using well–chosen time steps in CDS. This analysis offers stability conditions for phase–field, based on the Cahn–Hilliard Cook (CHC) equations of which CDS is the finite difference approximation. To overcome grid related artefacts (discretization errors) in the computational grid, the study has been done for employing an isotropic Laplacian operator in the CDS framework. Several 2D and 3D discrete Laplacians have been quantitatively compared for their isotropy. The novel 2D 9–point BV(D2Q9) isotropic stencil operators have been derived from the B.A.C. van Vlimmeren method and their isotropy measure has been determined optimally better than other exiting 2D 9–point discrete Laplacian operators. Overall, the stencils in 9–point family Laplacians in 2D and the 19–point stencil operators in 3D have been found to be optimal in terms of isotropy and time step stability. Considerable implementation of Laplacians with good isotropy has played an important role in achieving a proper structure factor in modelling methods of block copolymers. The novel models have been developed by implementing CDS via more stable implicit methods, including backward Euler, Crank–Nicolson (CN) and Alternating Direction Implicit (ADI) methods. The CN scheme were implemented for both one order and two order parameter systems in CDS and successful results were obtained compared to forward Euler method. Due to the implementation of implicit methods, the CDS has achieved second–order accuracy both in time and space and it has become stronger, robust and more stable technique for simulation of the phase–separation phenomena in soft materials.

APA, Harvard, Vancouver, ISO, and other styles

8

Hamburg, Maryanna P. "Financial Mathematical Tasks in a Middle School Mathematics Textbook Series: A Content Analysis." University of Akron / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=akron1258164585.

Full text

APA, Harvard, Vancouver, ISO, and other styles

9

Schick, Christian. "A mathematical analysis of foam films." [S.l. : s.n.], 2004. http://deposit.ddb.de/cgi-bin/dokserv?idn=972684247.

Full text

APA, Harvard, Vancouver, ISO, and other styles

10

Aydin, Ozlem. "Mathematical Analysis Of Peeling Of Carrots." Master's thesis, METU, 2005. http://etd.lib.metu.edu.tr/upload/12606514/index.pdf.

Full text

Abstract:

In this study, carrots of Beypazari variety, cultivated during 2004 season were chemically and steam peeled. Effects of temperature, concentration of NaOH solutions and immersion time on lye peeling of carrots were studied
optimum time-temperature-concentration relations were analyzed mathematically. Then suitable combinations of concentration, temperature and time were determined just by considering degree of peeling. Increases in both temperature and concentration of lye solution led to a decrease in peeling time. However it was observed that the temperature of the lye solution was the main effect on the quality of carrots. Treatment with 0.75 % NaOH at 77°
C for 10.5 minutes was found to be optimum to peel the carrots, mathematically. In steam peeling, the peeled surface area-time relations were analyzed mathematically. Complete peeling was achieved at 8.5 minutes. Under complete peeling conditions, the effect of chemical and steam peeling on quality of carrots were determined. Then the mathematical optimum value for chemical peeling was evaluated for quality parameters. The optimum chemical peeling value was fitted to the peeling yield-pectin relations. The peeling yield of steam peeled carrot was higher than the chemically peeled carrot. The color of the chemically peeled carrot had the highest consumer acceptance compared to conventional peeling. Finally, the two conditions were suitable for considering the need of the plant design.

APA, Harvard, Vancouver, ISO, and other styles

11

Kat, Bora. "Mathematical Modeling For Energy Policy Analysis." Phd thesis, METU, 2011. http://etd.lib.metu.edu.tr/upload/12613762/index.pdf.

Full text

Abstract:

As is now generally accepted, climate change and environmental degradation has largely been triggered by carbon emissions and energy modeling for policy analysis has therefore attained renewed urgency. It is important for governments to satisfy emission targets and timetables set down by international agreements without disregarding macroeconomic concerns and restrictions. In this study, we present a large-scale nonlinear optimization model that allows the analysis of macroeconomic and multi-sectoral energy policies in respect of technological and environmental options and scenarios. The model consists of a detailed representation of energy activities and disaggregates the rest of the economy into five main sectors. Economy-wide solutions are obtained by computing a utility maximizing aggregate consumption bundle on the part of a representative household. Intersectoral and foreign transaction balances are maintained using a modified accounting matrix. The model also computes the impact on macroeconomic variables of greenhouse gas (GHG) emission strategies and abatement schemes. As such the model is capable of producing solutions that can be used to benchmark regulatory instruments and policies. Several scenarios are presented for the case of Turkey in which the impact of a nuclear power programme and power generation coupled with carbon-capture-and-storage schemes are investigated as well as setting quotas on total and sectoral GHG emissions.

APA, Harvard, Vancouver, ISO, and other styles

12

Rezaei, Sadegh. "The mathematical analysis of crossover designs." Title page, contents and summary only, 1997. http://web4.library.adelaide.edu.au/theses/09PH/09phr4668.pdf.

Full text

APA, Harvard, Vancouver, ISO, and other styles

13

Williams, James R. "Mathematical analysis of algorithms within MANA." Thesis, Monterey, California: Naval Postgraduate School, 2014. http://hdl.handle.net/10945/42754.

Full text

Abstract:

Approved for public release; distribution is unlimited
MANA (Map Aware, Non-uniform, Automata) is an agent-based, time-stepped, stochastic mission-level modeling environment developed by the New Zealand Defense Technology Agency (DTA). While the MANA user manual goes into detail about setting up a scenario and navigating the user interface, it does not discuss some of the underlying mathematical procedures and algorithms resulting in many individuals utilizing MANA to analyze military operations without necessarily understanding how the results are achieved. The purpose of this thesis is to explore the mathematical formulas that MANA utilizes in an effort to aid in creating a more informed understanding of results reached by MANA. This work is intended as a supplement to the current MANA user manual. We will investigate how manipulating the parameters of the squads’ influence behavior on the battlefield. The format will follow a militarily oriented thought process of shoot, move and communicate, investigating mathematically how results are reached within the model. At the conclusion, there will be recommendations as to follow-up work.

APA, Harvard, Vancouver, ISO, and other styles

14

Leach, John Andrew. "Mathematical analysis of coupled chemical oscillators." Thesis, University of Leeds, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.305421.

Full text

APA, Harvard, Vancouver, ISO, and other styles

15

Hariki, Seiji. "Analysis of mathematical discourse : multiple perspectives." Thesis, University of Southampton, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.315400.

Full text

APA, Harvard, Vancouver, ISO, and other styles

16

Bura, Cotiso Andrei. "Mathematical frameworks for quantitative network analysis." Diss., Virginia Tech, 2019. http://hdl.handle.net/10919/95034.

Full text

Abstract:

This thesis is comprised of three parts. The first part describes a novel framework for computing importance measures on graph vertices. The concept of a D-spectrum is introduced, based on vertex ranks within certain chains of nested sub-graphs. We show that the D- spectrum integrates the degree distribution and coreness information of the graph as two particular such chains. We prove that these spectra are realized as fixed points of certain monotone and contractive SDSs we call t-systems. Finally, we give a vertex deletion algorithm that efficiently computes D-spectra, and we illustrate their correlation with stochastic SIR-processes on real world networks. The second part deals with the topology of the intersection nerve for a bi-secondary structure, and its singular homology. A bi-secondary structure R, is a combinatorial object that can be viewed as a collection of cycles (loops) of certain at most tetravalent planar graphs. Bi-secondary structures arise naturally in the study of RNA riboswitches - molecules that have an MFE binary structural degeneracy. We prove that this loop nerve complex has a euclidean 3-space embedding characterized solely by H2(R), its second homology group. We show that this group is the only non-trivial one in the sequence and furthermore it is free abelian. The third part further describes the features of the loop nerve. We identify certain disjoint objects in the structure of R which we call crossing components (CC). These are non-trivial connected components of a graph that captures a particular non-planar embedding of R. We show that each CC contributes a unique generator to H2(R) and thus the total number of these crossing components in fact equals the rank of the second homology group.
Doctor of Philosophy
This Thesis is divided into three parts. The first part describes a novel mathematical framework for decomposing a real world network into layers. A network is comprised of interconnected nodes and can model anything from transportation of goods to the way the internet is organized. Two key numbers describe the local and global features of a network: the number of neighbors, and the number of neighbors in a certain layer, a node has. Our work shows that there are other numbers in-between the two, that better characterize a node. We also give explicit means of computing them. Finally, we show that these numbers are connected to the way information spreads on the network, uncovering a relation between the network’s structure and dynamics on said network. The last two parts of the thesis have a common theme and study the same mathematical object. In the first part of the two, we provide a new model for the way riboswtiches organize themselves. Riboswitches, are RNA molecules within a cell, that can take two mutually opposite conformations, depending on what function they need to perform within said cell. They are important from an evolutionary standpoint and are actively studied within that context, usually being modeled as networks. Our model captures the shapes of the two possible conformations, and encodes it within a mathematical object called a topological space. Once this is done, we prove that certain numbers that are attached to all topological spaces carry specific values for riboswitches. Namely, we show that the shapes of the two possible conformations for a riboswich are always characterized by a single integer. In the last part of the Thesis we identify what exactly in the structure of riboswitches contributes to this number being large or small. We prove that the more tangled the two conformations are, the larger the number. We can thus conclude that this number is directly proportional to how complex the riboswitch is.

APA, Harvard, Vancouver, ISO, and other styles

17

Erceg, Ivan P. "Mathematical Analysis of a Geothermal System." Cleveland State University / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=csu1225138202.

Full text

APA, Harvard, Vancouver, ISO, and other styles

18

Sun, Liang. "Mathematical analysis of multicapillary supply region." Diss., Connect to online resource - MSU authorized users, 2008.

Find full text

APA, Harvard, Vancouver, ISO, and other styles

19

Wilkerson, Dorian. ""Mathermatical Analysis of a Truly Nonlinear Oscillator Differential Equation"." DigitalCommons@Robert W. Woodruff Library, Atlanta University Center, 2009. http://digitalcommons.auctr.edu/dissertations/101.

Full text

APA, Harvard, Vancouver, ISO, and other styles

20

Du, Toit Jacques Pierre. "The discrete pulse transform and applications." Thesis, Link to the online version, 2007. http://hdl.handle.net/10019/1052.

Full text

APA, Harvard, Vancouver, ISO, and other styles

21

Macdougall, Lindsey C. "Mathematical modelling of retinal metabolism." Thesis, University of Nottingham, 2015. http://eprints.nottingham.ac.uk/30615/.

Full text

Abstract:

Age-related macular degeneration and diabetic retinopathy, in which the cells at the back of the eye degrade due to age and diabetes respectively, are prevalent causes of vision loss in adults. We formulate mathematical models of retinal metabolic regulation to investigate defects that may be responsible for pathology. Continuum PDE models are developed to test whether rod photoreceptors, light detecting cells in the eye, may regulate their energy demand by adapting their length under light and dark conditions. These models assume photoreceptor length depends on the availability of nutrients, such as oxygen, which diffuse and are consumed within the photoreceptor. Our results suggest that the length is limited by oxygen and phosphocreatine shuttle-derived ATP under dark and light conditions respectively. Parameter sensitivity analysis indicates that lowered mitochondrial efficiency due to ageing may be responsible for the damage to and death of photoreceptors that are characteristic of age-related macular degeneration. In the latter part of this thesis we shift our focus to the inner retina and examine how metabolite levels in the tissue surrounding the neurons (highly sensitive, excitable cells that transmit electrical signals) are regulated by glial cells. For instance, stimulated neurons activate their neighbours via the release of the neurotransmitter glutamate, while glial cells regulate neuronal activity via glutamate uptake. Diabetes produces large fluctuations in blood glucose levels, and eventually results in neuronal cell death, causing vision loss. We generate an ODE model for the exchange of key metabolites between neurons and surrounding cells. Using numerical and analytical techniques, we use the model to show that the fluctuations in blood glucose and metabolic changes associated with diabetes may result in abnormally high glutamate levels in the inner retina, which could lead to neuronal damage via excitotoxicity (unregulated neuronal stimulation).

APA, Harvard, Vancouver, ISO, and other styles

22

Kheyfets, Boris Leonid. "Some stochastic properties of random classical and Carlitz compositions /." Philadelphia, Pa. : Drexel University, 2004. http://dspace.library.drexel.edu/handle/1860/309.

Full text

APA, Harvard, Vancouver, ISO, and other styles

23

Ohlsson, Henrik. "Mathematical Analysis of a Biological Clock Model." Thesis, Linköping University, Department of Electrical Engineering, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-6750.

Full text

Abstract:

Have you thought of why you get tired or why you get hungry? Something in your body keeps track of time. It is almost like you have a clock that tells you all those things.

And indeed, in the suparachiasmatic region of our hypothalamus reside cells which each act like an oscillator, and together form a coherent circadian rhythm to help our body keep track of time. In fact, such circadian clocks are not limited to mammals but can be found in many organisms including single-cell, reptiles and birds. The study of such rhythms constitutes a field of biology, chronobiology, and forms the background for my research and this thesis.

Pioneers of chronobiology, Pittendrigh and Aschoff, studied biological clocks from an input-output view, across a range of organisms by observing and analyzing their overt activity in response to stimulus such as light. Their study was made without recourse to knowledge of the biological underpinnings of the circadian pacemaker. The advent of the new biology has now made it possible to "break open the box" and identify biological feedback systems comprised of gene transcription and protein translation as the core mechanism of a biological clock.

My research has focused on a simple transcription-translation clock model which nevertheless possesses many of the features of a circadian pacemaker including its entrainability by light. This model consists of two nonlinear coupled and delayed differential equations. Light pulses can reset the phase of this clock, whereas constant light of different intensity can speed it up or slow it down. This latter property is a signature property of circadian clocks and is referred to in chronobiology as "Aschoff's rule". The discussion in this thesis focus on develop a connection and also a understanding of how constant light effect this clock model.

APA, Harvard, Vancouver, ISO, and other styles

24

Nahum, Carole. "Second order sensitivity analysis in mathematical programming." Thesis, McGill University, 1989. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=74349.

Full text

Abstract:

We consider a nonlinear mathematical program, with twice continuously differentiable functions.
If a point x$ sb0$ does not satisfy a certain Second Order Sufficient Condition (SOS) for optimality (that does not require any constraint qualification, see, e.g., BEN-ISRAEL, BEN-TAL and ZLOBEC (81)), then we prove that the knowledge of the second order properties (derivative, Hessian) of the functions is not enough to conclude that the point is optimal.
When the functions are continuously perturbed, what is the local behavior of an optimal solution x$ sb0$ and of the associate optimal value? The stability and sensitivity of the mathematical model are addressed. We present a new method for solving this problem. Our approach does not rely on the classical Lagrangian coefficients (which cannot be always defined) but rather on power series expansions because we use the primal formulations of optimality.
In the regular case, when Strict complementarity slackness holds, we recover Fiacco's results (FIACCO (83)). On the other hand, when Strict complementarity slackness does not hold, we extensively generalize Shapiro's Theorems (SHAPIRO (85)) since we do not assume Robinson's second order condition (ROBINSON (80)) but the SOS condition.
In the non-regular case, no general algorithm for computing the derivative of the optimizing point with respect to the parameters had been presented up to now.
The approach is extended to analyze the evolution of the set of Pareto minima of a multiobjective nonlinear program. In particular, we define the derivative of a point-to-set map. Our notion seems more adequate than the contingent derivative (AUBIN (81)), though the latter can easily be deduced from the former. This allows to get information about the sensitivity of the set of Pareto minima. A real-life example shows the usefulness and the simplicity of our results. Also, an application of our method to industry planning (within a general framework of Input Optimization) is made in the ideal case of a linear model.

APA, Harvard, Vancouver, ISO, and other styles

25

Smith, Ann Louise. "Mathematical analysis of discrete coagulation-fragmentation equations." Thesis, University of Strathclyde, 2011. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=15582.

Full text

APA, Harvard, Vancouver, ISO, and other styles

26

Shute, Hazel Anne. "Mathematical analysis of novel magnetic recording heads." Thesis, University of Plymouth, 1995. http://hdl.handle.net/10026.1/2392.

Full text

Abstract:

As a contribution to increasing the areal density of digital data stored on a magnetic recording medium, this thesis provides mathematical analyses of various magnetic recording heads. Each of the heads considered here is for use in a perpendicular recording system, writing to or reading from a multi-layer medium which includes a high magnetic permeability layer between the data storage layer and the substrate. The exact two-dimensional analysis is performed in each case by one of two methods: either Fourier analysis or conformal mapping. The types of heads analysed include conventional styles but particular emphasis is placed on the effects of the novel idea of potential grading across the pole pieces. Exact head fields are derived for thin film heads with both constant and linearly varying pole potentials, single pole heads with linearly and arbitrarily varying pole potentials and shielded magnetoresistive heads, all in the presence of a magnetic underlayer. These and other published solutions are used to derive output characteristics for perpendicular replay heads, which are compared with published theoretical and experimental results where possible. The Fourier solutions obtained are in the form of infinite series dependent on at least one set of coefficients which are determined by infinite systems of linear equations. Approximations to the potentials in the head face planes, independent of these coefficients, are derived from the exact Fourier solutions. The accuracy of these approximations is demonstrated when they are used to estimate the vertical field components and the spectral response functions. Heads with graded pole potentials are found to have more localised vertical field components than the corresponding constant potential heads. They are also better suited for use with thin media for 'in contact' recording.

APA, Harvard, Vancouver, ISO, and other styles

27

Pieterse, Cornelius Louwrens. "Mathematical and numerical analysis of electrospraying electrodynamics." Thesis, Stellenbosch : Stellenbosch University, 2014. http://hdl.handle.net/10019.1/95529.

Full text

Abstract:

Thesis (MEng) -- Stellenbosch University, 2014
ENGLISH ABSTRACT: The electrodynamics of arbitrary, point-to-plane electrospraying geometries, were investigated in this research both analytically and numerically. Electrospraying is the process during which particles of sizes in the nanometre range are simultaneously generated and charged by means of an applied electrostatic field. A high electrostatic potential is applied to a conductive capillary needle, which overcomes the force exerted by the liquid surface tension. One of the primary limitations of this process are corona discharges. The effect of corona discharges have not been studied quantitatively, even though it is frequently reported in the electrospraying literature. The main objective of this research was to understand the corona discharge thresholds associated with electrospraying. Previously, only one theoretical, and two empirical investigations studied this phenomenon, over a time period of approximately forty years. It was clear that by better understanding these thresholds, electrospraying could be applied much more effectively. A corona discharge threshold model is proposed, using either a numerical or analytical model for the calculation of polarization fields. When compared with the experimental results of other researchers, both these two models have average relative percentage errors of approximately 15%. These are the first models proposed in the literature for the calculation of electrospraying corona thresholds. A new method to determine surface tension using electrospraying is described theoretically. In addition to this method, the calculation of corona discharge thresholds have various applications. For example, the dynamics of electrostatic ion thrusters are much better described, powder production by means of electrospraying can be optimised, and pattern generation using pulsed electrospraying cone-jets can be optimised as well.
AFRIKAANSE OPSOMMING: Die elektrodinamika van arbitrêre, punt-tot-vlak elektrosproei geometrieë was beide analities en numeries ondersoek in hierdie tesis. Dit is die proses waartydens nanodeeltjies gelyktydig gegenereer en elektrostaties gelaai word. Deur 'n hoë elektriese potensiaal aan te lê tot 'n geleidende kapillêr, is dit moontlik om die krag van die oppervlakte spanning te oorkom. Een van die primêre beperkings van elektrosproei is corona ontladings. Die effek van corona ontladings was nog nie kwantitatief bestudeer nie, selfs al word dit dikwels rapporteer in die elektrosproei literatuur. Die primêre doel van hierdie navorsing was om die corona ontlading drempels te verstaan wat geassosieer word met elektrosproei. In die verlede was daar nog net een teoretiese, en twee empiriese ondersoeke gewees wat hierdie verskynsel bestuur het, oor 'n tydperk van ongeveer veertig jaar. Dit was duidelik dat deur 'n beter begrip te hê van hierdie elektrosproei drempels, kan hierdie proses baie meer doeltreffend toegepas word. In hierdie tesis word 'n corona ontlading drempel model voorgestel, wat gebruik maak van 'n analitiese of numeriese model om die polarisasie velde te bereken. Wanneer vergelyk met die resultate van ander navorsers, het beide die modelle 'n gemiddelde relatiewe persentasie fout van ongeveer 15%. Hierdie is die eerste modelle wat voorgestel word vir die berekening van corona ontlading drempels. Deur gebruik te maak van elektrosproei, word 'n nuwe metode ook voorgestel om die oppervlakte spanning te bereken. In byvoeging tot hierdie, het die berekening van corona ontlading drempels vele ander toepassings. As 'n voorbeeld, die dinamika van elektrostatiese ioon stuwers word beter beskryf, en poeier produksie deur middel van elektrosproei kan optimeer word.

APA, Harvard, Vancouver, ISO, and other styles

28

Datta, Samik. "A mathematical analysis of marine size spectra." Thesis, University of York, 2011. http://etheses.whiterose.ac.uk/1627/.

Full text

Abstract:

Aquatic ecosystems are observed to follow regular patterns in abundance. The frequency distribution of all individuals across the spectrum of body mass, irrespective of their taxonomic identity (known as a ’size spectrum’), follows a power law and this has mathematically been explained by the processes of growth and mortality primarily driven by predation. In this theory of the size spectrum, predation is driven by body size: as organisms grow bigger the size of their prey also increases. This process is thought to be particularly important for marine organisms such as fish, where individual body size is an important determinant for what they eat because they are mostly limited by the size of their mouths. Models need to capture the behaviour of real systems if reliable predictions are to emerge from them. Here, new equations for size-based predation are derived from a stochastic process, allowing variability in organism growth. The new equations are postulated to capture real feeding behaviour better than classical models often used to simulate size spectra. Marine systems are often perturbed by seasonal processes, environmental factors and exploitation. I show how models with diffusive growth stabilise the observed power-law steady state in marine systems, and stability is explicitly linked to parameters involved in feeding. Seasonal plankton blooms are introduced into the model, along with time-dependent reproduction, both of which are widely observed in aquatic systems. The population dynamics, along with growth and survival rates during blooms are investigated, and preliminary results are reflected in empirical data. The match/mismatch hypothesis is tested, with theoretical findings in agreement with observed seasonal trends. Adding factors such as these will make the behaviour of size-based models more indicative of real ecosystems, and thus well-informed management decisions about exploitation can be made.

APA, Harvard, Vancouver, ISO, and other styles

29

Sun, Qian. "Mathematical analysis of microflows under electroosmotic forces." Thesis, Curtin University, 2013. http://hdl.handle.net/20.500.11937/2613.

Full text

Abstract:

This thesis is concerned with the transient flows of Newtonian fluids in micro-channels. Different flow-driving mechanisms and micro-slip on boundary are taken into account. By using the complex variable method combined with the Fourier series expansion in time and Bessel functions in space, the underlying boundary value problems are solved and a subsequent investigation is carried out to study the flow dynamics and the control of flow pattern and behaviour.

APA, Harvard, Vancouver, ISO, and other styles

30

Nikishkov, Yuri G. "Computational stability analysis of dynamical systems." Diss., Georgia Institute of Technology, 2000. http://hdl.handle.net/1853/12149.

Full text

APA, Harvard, Vancouver, ISO, and other styles

31

Satyal, Neeraj Raj. "An Analysis of Fifth-Grade Teachers’ Mathematical Inputs on Eighth-Grade Students’ Mathematical Outputs." Digital Commons at Loyola Marymount University and Loyola Law School, 2015. https://digitalcommons.lmu.edu/etd/183.

Full text

Abstract:

The purpose of this study was to explore and analyze which fifth-grade teacher inputs were the most important predictors of future outcomes of eighth-grade math students. This quantitative study looked at mathematical achievement through the lens of an education production function. The three inputs that were analyzed were fifth-grade teachers’ background; perception of professional development; and instructional practices and the relationship of those practices to achievement in eighth-grade math. In order to find the relationship between the above variables and student achievement, descriptive statistics, multiple correlations, and multi-variable regression analysis were conducted to examine which predictors had a stronger relationship between eighth-grade math outcomes than others. Taken as a whole, fifth-grade teacher math inputs in this study seemed to explain a small part of the variance regarding eighth-grade math achievement. As a whole, the more frequently students wrote and spoke about math in fifth grade as well as used math tools effectively, the better the outcome in eighth grade.

APA, Harvard, Vancouver, ISO, and other styles

32

Satyal, Neeraj. "An analysis of fifth-grade teachers' mathematical inputs on eighth-grade students' mathematical outputs." Thesis, Loyola Marymount University, 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=3723016.

Full text

Abstract:

The purpose of this study was to explore and analyze which fifth-grade teacher inputs were the most important predictors of future outcomes of eighth-grade math students. This quantitative study looked at mathematical achievement through the lens of an education production function. The three inputs that were analyzed were fifth-grade teachers’ background; perception of professional development; and instructional practices and the relationship of those practices to achievement in eighth-grade math. In order to find the relationship between the above variables and student achievement, descriptive statistics, multiple correlations, and multi-variable regression analysis were conducted to examine which predictors had a stronger relationship between eighth-grade math outcomes than others. Taken as a whole, fifth-grade teacher math inputs in this study seemed to explain a small part of the variance regarding eighth-grade math achievement. As a whole, the more frequently students wrote and spoke about math in fifth grade as well as used math tools effectively, the better the outcome in eighth grade.

APA, Harvard, Vancouver, ISO, and other styles

33

Majin, Wodu. "Mathematical modelling of GPCR-mediated calcium signalling." Thesis, University of Nottingham, 2012. http://eprints.nottingham.ac.uk/12451/.

Full text

Abstract:

Ca2+ is an important messenger which mediates several physiological functions, including muscle contraction, fertilisation, heart regulation and gene transcription. One major way its cytosolic level is raised is via a G-protein coupled receptor (GPCR)- mediated release from intracellular stores. GPCR’s are the target of approximately 50% of all drugs in clinical use. Hence, understanding the underlying mechanisms of signalling in this pathway could lead to improved therapy in disease conditions associated with abnornmal Ca2+ signalling, and to the identification of new drug targets. To gain such insight, this thesis builds and analyses a detailed mathematical model of key processes leading to Ca2+ mobilisation. Ca2+ signalling is considered in the particular context of the M3 muscarinic receptor system. Guided by available data, the Ca2+ mobilisation model is assembled, first by analysing a base G-protein activation model, and subsequently extending it with downstream details. Computationally efficient designs of a global parameter sensitivity analysis method are used to identify the key controlling parameters with respect to the main features of the Ca2+ data. The underlying mechanism behind the experimentally observed, rapid, amplified Ca2+ response is shown to be a rapid rate of inositol trisphosphate (IP3) formation from Phosphatidylinositol 4,5-bisphosphate (PIP2) hydrolysis. Using the same results, potential drug targets (apart fromthe GPCR) are identified, including the sarco/endoplasmic reticulum Ca2+-ATPase (SERCA) and PIP2. Moreover, possible explanations for therapeutic failures were found when some parameters exerted a biphasic effect on the relative Ca2+ increase. The sensitivity analysis results are used to simplify the process of parameter estimation by a significant reduction of the parameter space of interest. An evolutionary algorithm is used to successfully fit the model to a significant portion of the Ca2+ data. Subsequent sensitivity analyses of the best-fitting parameter sets suggest that mechanistic modelling of kinase-mediated GPCR desensitisation, and SERCA dynamics may be required for a comprehensive representation of the data.

APA, Harvard, Vancouver, ISO, and other styles

34

Hiorns, Jonathan E. "Mathematical modelling and imaging of asthmatic airways." Thesis, University of Nottingham, 2014. http://eprints.nottingham.ac.uk/14440/.

Full text

Abstract:

The hyper-responsiveness of airway smooth muscle to certain external stimuli, and the associated remodelling of the airway wall, is central to the development of asthma, making it of widespread clinical significance. In this thesis, mathematical models for the asthmatic airway embedded in parenchymal tissue are presented. The stiffening due to recruitment of collagen fibres and force generation by smooth muscle is taken into account, to develop a nonlinear elastic model for the airway wall. The contractile force of the muscle is governed by the dynamically changing subcellular crossbridge populations. A nonlinear elastic and, to take into account the viscoelasticity of the lung, a linear viscoelastic model for the parenchyma are developed. Consistent with experimental findings, deforming the airway passively, the model predicts strain-stiffening on inflation and deflation. The displacements predicted within the parenchyma are much smaller when the airway is inflated internally than externally, due to the airway wall shielding the parenchyma. Stress heterogeneities are predicted within the thickened airway wall when active contractile forcing is applied, which may contribute to further remodelling of the wall. If tidal stretching is applied to a contracted airway, the model predicts that the contractile force reduces, resulting in a reversal of bronchoconstriction. This is more exaggerated when the parenchyma is viscoelastic. Image analysis techniques are also developed to investigate data from lung-slice experiments, whereby pharmacological stimuli can be added to segments of lung tissue to stimulate smooth muscle contraction. By tracking the lumen area and fitting to exponential functions, two timescales of contraction are found to exist, consistent with the mathematical model predictions, and that the ratio of the timescales is robust. Methods are also developed and tested to find the displacement field of the tissue surrounding the airway lumen and it is shown that there are important heterogeneities within the tissue.

APA, Harvard, Vancouver, ISO, and other styles

35

Collazo, Antonio. "The Mathematical Landscape." Scholarship @ Claremont, 2011. http://scholarship.claremont.edu/cmc_theses/116.

Full text

Abstract:

The intent of this paper is to present the reader will enough information to spark a curiosity in to the subject. By no means is the following a complete formulation of any of the topics covered. I want to give the reader a tour of the mathematical landscape. There are plenty of further details to explore in each section, I have just touched the tip the iceberg. The work is basically in four sections: Numbers, Geometry, Functions, Sets and Logic, which are the basic building blocks of Math. The first sections are a exposition into the mathematical objects and their algebras. The last section dives into the foundation of math, sets and logic, and develops the ``language'' of Math. My hope is that after this, the reader will have the necessary (maybe not sufficient) information needed to talk the language of Math.

APA, Harvard, Vancouver, ISO, and other styles

36

Stroinska, Maria Magdalena. "Indirect reference in German mathematical discourse." Thesis, University of Edinburgh, 1987. http://hdl.handle.net/1842/24351.

Full text

APA, Harvard, Vancouver, ISO, and other styles

37

Ward, John P. "Mathematical modelling of avascular tumour growth." Thesis, University of Nottingham, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.339566.

Full text

APA, Harvard, Vancouver, ISO, and other styles

38

Jakobsson-Åhl, Teresia. "Encouraging Participation in Mathematical Practices : Messages in the Boost for Mathematics." Thesis, Luleå tekniska universitet, Institutionen för konst, kommunikation och lärande, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-67660.

Full text

Abstract:

In this thesis, focused attention is given to the idea of task solvers as active participants in mathematical practices. The theoretical assumptions of the study, reported in this thesis, are inspired by socio-political concerns. The aim of the study is to investigate the underlying view of participation in mathematical practices, as understood in a nationwide teacher professional development programme, the Boost for Mathematics, in Sweden. To be more precise, the study is arranged to problematise ways of encouraging students as active participants. This aim is approached by means of the following research questions: (1) What messages do mathematical tasks in the Boost for Mathematics send about people as participants in mathematical practices? and (2) What is the role of multiple representations in these messages? An empirical study is reported. The data of the study, i.e., three collections of problems, are drawn from the Boost for Mathematics. Data processing is conducted by using a modified version of a pre-existing data processing framework, focusing on mathematical practices as socio-political practices. The empirical study uncovers an implicit view of task solvers in mathematical practices and especially a detachment between students, as potential task solvers, and the social contexts where mathematical ideas and concepts are embedded. This implicit view is challenged from the assumption that it is motivating for a student to conceive him/herself as someone who is ‘qualified’ to take part in mathematical practices.

APA, Harvard, Vancouver, ISO, and other styles

39

Bråting, Kajsa. "Studies in the Conceptual Development of Mathematical Analysis." Doctoral thesis, Uppsala universitet, Matematiska institutionen, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-101349.

Full text

Abstract:

This dissertation deals with the development of mathematical concepts from a historical and didactical perspective. In particular, the development of concepts in mathematical analysis during the 19th century is considered. The thesis consists of a summary and three papers. In the first paper we investigate the Swedish mathematician E.G. Björling's contribution to uniform convergence in connection with Cauchy's sum theorem from 1821. In connection to Björling's convergence theory we discuss some modern interpretations of Cauchy's expression x=1/n. We also consider Björling's convergence conditions in view of Grattan-Guinness distinction between history and heritage. In the second paper we study visualizations in mathematics from historical and didactical perspectives. We consider some historical debates regarding the role of intuition and visual thinking in mathematics. We also consider the problem of what a visualization in mathematics can achieve in learning situations. In an empirical study we investigate what mathematical conclusions university students made on the basis of a visualization. In the third paper we consider Cauchy's theorem on power series expansions of complex valued functions on the basis of a paper written by E.G. Björling in 1852. We discuss Björling's, Lamarle's and Cauchy's different conditions for expanding a complex valued function in a power seris. In the third paper we also discuss the problem of the ambiguites of fundamental concpets that existed during the mid-19th century. We argue that Cauchy's and Lamarle's proofs of Cauchy's theorem on power series expansions of complex valued functions are correct on the basis of their own definitions of the fundamental concepts involved.

APA, Harvard, Vancouver, ISO, and other styles

40

Ugon, Julien. "Application of nonsmooth optimisation to data analysis." Thesis, University of Ballarat, 2005. http://researchonline.federation.edu.au/vital/access/HandleResolver/1959.17/41666.

Full text

Abstract:

The research presented in this thesis is two-fold: on the one hand, major data mining problems are reformulated as mathematical programming problems. These problems should be carefully designed, since from their formulation depends the efficiency, perhaps the existence, of the solvers. On the other hand, optimisation methods are adapted to solve these problems, most of which are nonsmooth and nonconvex. This part is delicate, as the solution is often required to be good and obtained fast. Numerical experiments on real-world datasets are presented and analysed.
Doctor of Philosophy

APA, Harvard, Vancouver, ISO, and other styles

41

Lindgren, Erik. "Regularity properties of two-phase free boundary problems." Doctoral thesis, KTH, Matematik (Inst.), 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-10336.

Full text

Abstract:

This thesis consists of four papers which are all related to the regularity properties of free boundary problems. The problems considered have in common that they have some sort of two-phase behaviour.In papers I-III we study the interior regularity of different two-phase free boundary problems. Paper I is mainly concerned with the regularity properties of the free boundary, while in papers II and III we devote our study to the regularity of the function, but as a by-product we obtain some partial regularity of the free boundary.The problem considered in paper IV has a somewhat different nature. Here we are interested in certain approximations of the obstacle problem. Two major differences are that we study regularity properties close to the fixed boundary and that the problem converges to a one-phase free boundary problem.
QC 20100728

APA, Harvard, Vancouver, ISO, and other styles

42

Teuscher, Dawn. "Two paths to advanced placement calculus an examination of secondary students' mathematical understanding emerging from integrated and single-subject curricula /." Diss., Columbia, Mo. : University of Missouri-Columbia, 2008. http://hdl.handle.net/10355/5530.

Full text

Abstract:

Thesis (Ph. D.)--University of Missouri-Columbia, 2008.
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 June 17, 2009) Vita. Includes bibliographical references.

APA, Harvard, Vancouver, ISO, and other styles

43

Vorwerk, Michael Conrad. "A mathematical study of mimicry and opportunism." Thesis, Georgia Institute of Technology, 1989. http://hdl.handle.net/1853/28944.

Full text

APA, Harvard, Vancouver, ISO, and other styles

44

Blum, Peter. "On some mathematical aspects of dynamic financial analysis /." Zürich, 2005. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=15907.

Full text

APA, Harvard, Vancouver, ISO, and other styles

45

Dahl, Lars Oswald. "Numerical analysis and stochastic modeling in mathematical finance." Doctoral thesis, Norwegian University of Science and Technology, Department of Mathematical Sciences, 2002. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-1678.

Full text

Abstract:

The main goal of this thesis has been to study and develop faster and more accurate methods for pricing and hedging exotic options. This has involved work on models describing prices and hedges as well as the stochastics driving them. We have also put effort into algorithmic interpretation and implementation of the models to enable efficiency measurement with regards to computing time. In some of the articles we have aspired to find criteria to decide whether the pricing methods we have developed can be expected to perform well, enabling practicians to find a good numerical method for their given pricing/hedging problem easier. However, the most optimistic reader must be warned: We have not found one single method that works best for all types of option pricing problems, and we do not think that sucj a method exists. Pricing and hedging of exotic options involve thorough knowledge of the problem at hand, and the mastering of a tool box of numerical methods from which a suitible one can be picket. We beleive, however, that the thesis contributes som to the enlargement of the tool box.

APA, Harvard, Vancouver, ISO, and other styles

46

Nordle, Bjorn, and Marcus Johansson. "Analysis and mathematical modelling of industrial truck silencers." Thesis, Växjö University, School of Mathematics and Systems Engineering, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:vxu:diva-1808.

Full text

Abstract:

The currently low requirements on sound emissions for industrial trucks are expected to be raised in the near future. The company Kalmar Industries AB, which develop, produce and market industrial trucks, want to improve their truck silencers as a precaution to the future harder restrictions and also to improve their competitiveness. The sound emission produced by a vehicle depends on type and range of application it is designed for but the dominant part of the sound is usually produced by the engine and silencer.

A new measuring method is developed for studying sound emanating through the silencer system. The analysis of the measurement data establishes that the silencers are not working well. The simulations made with SIDLAB, which is a computer programme for calculating the propagation of sound in ducts, confirms that the silencers are inefficient and that they are simply too small.

A simulation which implements a parallel resonator in the main silencer shows that it is possible to make great improvements in reducing the noise from the truck as well as meeting requirements on space.

Mathematical modelling based on linearity and one-dimensional interaction between the silencer elementsis advantageous and gives very good results when understanding, analysing and simulating the silencer. The simulation tool SIDLAB works well and saves a lot of time by its fast modelling and easy interface.

APA, Harvard, Vancouver, ISO, and other styles

47

Pramuanjaroenkij, Anchasa. "Mathematical Analysis of Planar Solid Oxide Fuel Cells." Scholarly Repository, 2009. http://scholarlyrepository.miami.edu/oa_dissertations/234.

Full text

Abstract:

The mathematical analysis has been developed by using finite volume method, experimental data from literatures, and solving numerically to predict solid oxide fuel cell performances with different operating conditions and different material properties. The in-house program presents flow fields, temperature distributions, and performance predictions of typical solid oxide fuel cells operating at different temperatures, 1000 C, 800 C, 600 C, and 500 C, and different electrolyte materials, Yttria-Stabilized zirconia (YSZ) and Gadolinia-doped ceria (CGO). From performance predictions show that the performance of an anode-supported planar SOFC is better than that of an electrolyte-supported planar SOFC for the same material used, same electrode electrochemical considerations, and same operating conditions. The anode-supported solid oxide fuel cells can be used to give the high power density in the higher current density range than the electrolyte-supported solid oxide fuel cells. Even though the electrolyte-supported solid oxide fuel cells give the lower power density and can operate in the lower current density range but they can be used as a small power generator which is portable and provide low power. Furthermore, it is shown that the effect of the electrolyte materials plays important roles to the performance predictions. This should be noted that performance comparisons are obtained by using the same electrode materials. The YSZ-electrolyte solid oxide fuel cells in this work show higher performance than the CGO-electrolyte solid oxide fuel cells when SOFCs operate above 756 C. On the other hand, when CGO based SOFCs operate under 756 C, they shows higher performance than YSZ based SOFCs because the conductivity values of CGO are higher than that of YSZ temperatures lower than 756 C. Since the CGO conductivity in this work is high and the effects of different electrode materials, they can be implied that conductivity values of electrolyte and electrode materials have to be improved.

APA, Harvard, Vancouver, ISO, and other styles

48

Lam, Hoi Ieng Helen. "Mathematical tools for ventricular analysis using cardiac MRI." Thesis, University of Auckland, 2012. http://hdl.handle.net/2292/12974.

Full text

Abstract:

Non-invasive imaging techniques are now being used routinely for the analysis of cardiac function. The objective of this thesis was to develop mathematical modelling tools for the semi-automatic quantification of cardiac structure and function from magnetic resonance imaging (MRI). Two main problem areas were considered. Firstly, tools were developed to investigate the changes in cardiac function and myofibre structure during the progression of myocardial infarction, and the effect of using angiotensin-converting enzyme inhibitor (ACEI) as a treatment of myocardial infarction. Ex vivo diffusion tensor MRI (DTMRI) could then be compared with in vivo myocardial strain from MRI tissue tagging. These tools were applied to data from four healthy male Sprague Dawley rats, and eight with myocardial infarction induced by ligating the left anterior descending artery. Half of the infarcted rats were treated by ACEI. The results showed that myocyte structure as well as function were altered in myocardial infarction, altering the correlations between structure and function. A positive correlation between strain and fractional isotropy in the control group became negative in the infarct group and did not change with ACEI. Strain was positively correlated with the proportion of left-handed myofibres in the control group. This relationship was not significant in the infarct group but returned in the ACEI group. The results from these preliminary studies indicate that treatment with ACEI helps to restore normal myocardial structure-function relationships. Secondly, a modelling tool was developed for the efficient evaluation of right and left ventricular function in standard cine MRI imaging examinations. The biventricular modelling tool used a human biventricular deformable model, which was developed based on a porcine model, for customisation to cardiac MRI data. The customisation used an interactive guide point modelling technique which was modified to include a `predictor' step using a host mesh fitting algorithm, thereby obtaining a significant decrease in solution time. The tool was applied to cine MRI data of seventeen patients with various types of congenital heart disease. The results were compared against with those obtained from a current gold standard technique. The comparison showed generally good agreement between the two methods, in terms of both the reproducibility of global cardiac function measurements and the reproducibility between analysts. In conclusion, the tools developed in this thesis enabled novel examinations of cardiac structure and function in animal models and humans with cardiac disease.
Whole document restricted until Mar. 2014, but available by request, use the feedback form to request access.

APA, Harvard, Vancouver, ISO, and other styles

49

Coskun, Arslan Hakan. "Stochastic Characterization And Mathematical Analysis Of Feedforward Linearizers." Phd thesis, METU, 2003. http://etd.lib.metu.edu.tr/upload/626721/index.pdf.

Full text

Abstract:

Feedforward is known to be one of the best methods for power amplifier linearization due to its superior linearization performance and broadband stable operation. However feedforward systems have relatively poor power efficiency and are complicated due to the presence of two nonlinear amplifiers and the requirements of amplitude, phase and delay matching within two different loops. In this thesis stochastic characterization of a simple feedforward system with autocorrelation analysis has been presented for Code Division Multiple Access (CDMA) applications taking the amplitude and delay mismatches into consideration. It has been assumed that, the input signal can be represented as Gaussian noise, main and error amplifiers can be modeled with third order AM/AM nonlinearities and there exists no phase mismatch within the loops. Hence closed form expressions, which relate the main channel and distorted adjacent channel power at any point in the feedforward circuitry to the system parameters, have been obtained. Consequently, a mathematical handy tool is achieved towards specifying the circuit parameters rapidly for optimum linearity performance and efficiency. The developed analytical model has been verified by Radio Frequency (RF) and system simulations. An alternative approach towards modeling feedforward systems for arbitrary signals has also been brought into consideration and has been verified with system simulations.

APA, Harvard, Vancouver, ISO, and other styles

50

Roschat, Christina [Verfasser]. "Mathematical Analysis of Marine Ecosystem Models / Christina Roschat." Kiel : Universitätsbibliothek Kiel, 2016. http://d-nb.info/1111558604/34.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Dissertations / Theses on the topic 'Mathematical analysis'

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