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Ordinary Differential Equations and Applied Dynamics

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Articles 361 - 390 of 848

Full-Text Articles in Applied Mathematics

Undetermined Coefficients: A Fully Generalized Approach, Taylor Powell Mar 2021

Undetermined Coefficients: A Fully Generalized Approach, Taylor Powell

Undergraduate Research Symposium

In this presentation, I outline the development of a fully-generalized solution of linear, non-homogeneous differential equations with constant coefficients and whose non-homogeneous function is any product of sinusoidal, exponential, and polynomial functions. This particular method does not require the reader to work with annihilator operators or additional related ODEs, and only requires an understanding of summation notation, matrix multiplication, and calculus. Additionally, this method provides a straightforward way to develop a program to implement the technique, and potentially reduces the time-complexity for solutions with comparisons to other methods.


Long-Term Dynamics Of The Kidney Disease Epidemic Among Hiv-Infected Individuals, Heather Gudaz, Henry A. Ogu, Elissa J. Schwartz Feb 2021

Long-Term Dynamics Of The Kidney Disease Epidemic Among Hiv-Infected Individuals, Heather Gudaz, Henry A. Ogu, Elissa J. Schwartz

Spora: A Journal of Biomathematics

One of many risks facing HIV+ individuals is the development of kidney dysfunction and end stage kidney disease (ESKD). A differential equation-based mathematical model was developed to assess the impact of antiretroviral therapy on the progression to kidney disease and on reducing mortality due to kidney failure. Analytical and numerical predictions of long-term HIV+ ESKD prevalence show that therapy can lead to either extremely low levels of disease prevalence or increased prevalence, depending on drug efficacy levels and mechanisms of action. Maintenance of HIV+ ESKD prevalence below one individual is possible with sufficient efficacy (e.g., 99%) against the progression from …


Green's Function For The Schrodinger Equation With A Generalized Point Interaction And Stability Of Superoscillations, Yakir Aharonov, Jussi Behrndt, Fabrizio Colombo, Peter Schlosser Jan 2021

Green's Function For The Schrodinger Equation With A Generalized Point Interaction And Stability Of Superoscillations, Yakir Aharonov, Jussi Behrndt, Fabrizio Colombo, Peter Schlosser

Mathematics, Physics, and Computer Science Faculty Articles and Research

In this paper we study the time dependent Schrödinger equation with all possible self-adjoint singular interactions located at the origin, which include the δ and δ'-potentials as well as boundary conditions of Dirichlet, Neumann, and Robin type as particular cases. We derive an explicit representation of the time dependent Green's function and give a mathematical rigorous meaning to the corresponding integral for holomorphic initial conditions, using Fresnel integrals. Superoscillatory functions appear in the context of weak measurements in quantum mechanics and are naturally treated as holomorphic entire functions. As an application of the Green's function we study the stability …


Modelling The Transition From Homogeneous To Columnar States In Locust Hopper Bands, Miguel Velez Jan 2021

Modelling The Transition From Homogeneous To Columnar States In Locust Hopper Bands, Miguel Velez

HMC Senior Theses

Many biological systems form structured swarms, for instance in locusts, whose swarms are known as hopper bands. There is growing interest in applying mathematical models to understand the emergence and dynamics of these biological and social systems. We model the locusts of a hopper band as point particles interacting through repulsive and attractive social "forces" on a one dimensional periodic domain. The primary goal of this work is to modify this well studied modelling framework to be more biological by restricting repulsion to act locally between near neighbors, while attraction acts globally between all individuals. This is a biologically motivated …


A Generalized Polar-Coordinate Integration Formula, Oscillatory Integral Techniques, And Applications To Convolution Powers Of Complex-Valued Functions On $\Mathbb{Z}^D$, Huan Q. Bui Jan 2021

A Generalized Polar-Coordinate Integration Formula, Oscillatory Integral Techniques, And Applications To Convolution Powers Of Complex-Valued Functions On $\Mathbb{Z}^D$, Huan Q. Bui

Honors Theses

In this thesis, we consider a class of function on $\mathbb{R}^d$, called positive homogeneous functions, which interact well with certain continuous one-parameter groups of (generally anisotropic) dilations. Generalizing the Euclidean norm, positive homogeneous functions appear naturally in the study of convolution powers of complex-valued functions on $\mathbb{Z}^d$. As the spherical measure is a Radon measure on the unit sphere which is invariant under the symmetry group of the Euclidean norm, to each positive homogeneous function $P$, we construct a Radon measure $\sigma_P$ on $S=\{\eta \in \mathbb{R}^d:P(\eta)=1\}$ which is invariant under the symmetry group of $P$. With this measure, we prove …


Cross-Model Parameter Estimation In Epidemiology, Julia R. Fitzgibbons Jan 2021

Cross-Model Parameter Estimation In Epidemiology, Julia R. Fitzgibbons

Honors Theses and Capstones

No abstract provided.


Buckling Loads Of A Graphene Layer Interacting With Rigid Substrates, Bradley Beckwith Jan 2021

Buckling Loads Of A Graphene Layer Interacting With Rigid Substrates, Bradley Beckwith

Williams Honors College, Honors Research Projects

The goal of this project is to formulate a model that can predict the buckling of a graphene layer between two rigid substrates. The model will predict the buckling of the graphene layer when it is parallel to the substrates and an edge load is applied to the ends of the layer. Our main focus is to use the model to predict buckling loads given different assumptions for interaction forces between the graphene layer and the substrates. For this project continuum modeling will be used to create a model for the graphene buckling problem. This modeling leads to a total …


Supercritical And Subcritical Pitchfork Bifurcations In A Buckling Problem For A Graphene Sheet Between Two Rigid Substrates, Jake Grdadolnik Jan 2021

Supercritical And Subcritical Pitchfork Bifurcations In A Buckling Problem For A Graphene Sheet Between Two Rigid Substrates, Jake Grdadolnik

Williams Honors College, Honors Research Projects

In this paper we study a model of the buckling of a sheet of graphene between two rigid substrates. We seek to understand the buckling of the sheet as the substrate separation is varied with a fixed load on each end of the sheet. We write down the expression for total energy of the system and from it derive a 2-point nonlinear boundary-value problem whose solutions are equilibrium configurations of the sheet. We cannot get an explicit solution. Instead, we perform a bifurcation analysis by using asymptotics to approximate solutions on the bifurcating branches near the bifurcation points. The bifurcating …


Stability Theory Of Nonlinear Differential Equations, Jiaxiao Wei Jan 2021

Stability Theory Of Nonlinear Differential Equations, Jiaxiao Wei

Graduate Theses/Dissertations

Nonlinear differential equations are often effective tools in modeling some important phenomena in nature. However, most of the nonlinear ordinary differential equation cannot be solved by analytical methods. A more effective way is to explore the prop- erties of critical point and the trajectory around it. In this study, I will focus on sys- tems of autonomous differential equations, linear as well as nonlinear. I will not only focus on the stability of equilibria but also the orbital stability of nonlinear differential equations. I will introduce various approaches to the study of equilibrium points of the system in terms of …


Analytic Solutions For Diffusion On Path Graphs And Its Application To The Modeling Of The Evolution Of Electrically Indiscernible Conformational States Of Lysenin, K. Summer Ware Dec 2020

Analytic Solutions For Diffusion On Path Graphs And Its Application To The Modeling Of The Evolution Of Electrically Indiscernible Conformational States Of Lysenin, K. Summer Ware

Boise State University Theses and Dissertations

Memory is traditionally thought of as a biological function of the brain. In recent years, however, researchers have found that some stimuli-responsive molecules exhibit memory-like behavior manifested as history-dependent hysteresis in response to external excitations. One example is lysenin, a pore-forming toxin found naturally in the coelomic fluid of the common earthworm Eisenia fetida. When reconstituted into a bilayer lipid membrane, this unassuming toxin undergoes conformational changes in response to applied voltages. However, lysenin is able to "remember" past history by adjusting its conformational state based not only on the amplitude of the stimulus but also on its previous …


Estimation Of Transmission Dynamics Of Covid-19 In India: The Influential Saturated Incidence Rate, - Tanvi, Rajiv Aggarwal, Ashutosh Rajput Dec 2020

Estimation Of Transmission Dynamics Of Covid-19 In India: The Influential Saturated Incidence Rate, - Tanvi, Rajiv Aggarwal, Ashutosh Rajput

Applications and Applied Mathematics: An International Journal (AAM)

A non-linear SEIR mathematical model for coronavirus disease in India has been proposed, by incorporating the saturated incidence rate on the occurrence of new infections. In the model, the threshold quantity known as the reproduction number is evaluated which determines the stability of disease-free equilibrium and the endemic equilibrium points. The disease-free equilibrium point becomes globally asymptotically stable when the corresponding reproduction number is less than unity, whereas, if it is greater than unity then the endemic equilibrium point comes into existence, which is locally asymptotically stable under certain restrictions on the parameters value in the model. The impact of …


Impulse Effect On The Food-Limited Population Model With Piecewise Constant Argument, Fatma Karakoç Dec 2020

Impulse Effect On The Food-Limited Population Model With Piecewise Constant Argument, Fatma Karakoç

Applications and Applied Mathematics: An International Journal (AAM)

The qualitative study of mathematical models is an important area in applied mathematics. In this paper, a version of the food-limited population model with piecewise constant argument under impulse effect is investigated. Differential equations with piecewise constant arguments are related to difference equations. First, a representation for the solutions of the food-limited population model is stated in terms of the solutions of corresponding difference equation. Then using linearized oscillation theory for difference equations, a sufficient condition for the oscillation of the solutions about positive equilibrium point is obtained. Moreover, asymptotic behavior of the non-oscillatory solutions are investigated. Later, applying the …


Exact Solutions Of Two Nonlinear Space-Time Fractional Differential Equations By Application Of Exp-Function Method, Elahe M. Eskandari, Nasir Taghizadeh Dec 2020

Exact Solutions Of Two Nonlinear Space-Time Fractional Differential Equations By Application Of Exp-Function Method, Elahe M. Eskandari, Nasir Taghizadeh

Applications and Applied Mathematics: An International Journal (AAM)

In this paper, we discuss on the exact solutions of the nonlinear space-time fractional Burgerlike equation and also the nonlinear fractional fifth-order Sawada-Kotera equation with the expfunction method.We use the functional derivatives in the sense of Riemann-Jumarie derivative and fractional convenient variable transformation in this study. Further, we obtain some exact analytical solutions including hyperbolic function.


Classification Of Some First Order Functional Differential Equations With Constant Coefficients To Solvable Lie Algebras, J. Z. Lobo, Y. S. Valaulikar Dec 2020

Classification Of Some First Order Functional Differential Equations With Constant Coefficients To Solvable Lie Algebras, J. Z. Lobo, Y. S. Valaulikar

Applications and Applied Mathematics: An International Journal (AAM)

In this paper, we shall apply symmetry analysis to some first order functional differential equations with constant coefficients. The approach used in this paper accounts for obtaining the inverse of the classification. We define the standard Lie bracket and make a complete classification of some first order linear functional differential equations with constant coefficients to solvable Lie algebras.We also classify some nonlinear functional differential equations with constant coefficients to solvable Lie algebras.


Dynamical Behavior Of An Eco-Epidemiological Model Incorporating Prey Refuge And Prey Harvesting, Dawit Melese, Ousman Muhye, Subrata K. Sahu Dec 2020

Dynamical Behavior Of An Eco-Epidemiological Model Incorporating Prey Refuge And Prey Harvesting, Dawit Melese, Ousman Muhye, Subrata K. Sahu

Applications and Applied Mathematics: An International Journal (AAM)

In this paper an eco-epidemiological model incorporating a prey refuge and prey harvesting with disease in the prey-population is considered. Predators are assumed to consume both the susceptible and infected prey at different rates. The positivity and boundedness of the solution of the system are discussed. The existence and stability of the biologically feasible equilibrium points are investigated. Numerical simulations are performed to support our analytical findings.


Controlling And Synchronizing Combined Effect Of Chaos Generated In Generalized Lotka-Volterra Three Species Biological Model Using Active Control Design, Taqseer Khan, Harindri Chaudhary Dec 2020

Controlling And Synchronizing Combined Effect Of Chaos Generated In Generalized Lotka-Volterra Three Species Biological Model Using Active Control Design, Taqseer Khan, Harindri Chaudhary

Applications and Applied Mathematics: An International Journal (AAM)

In this work, we study hybrid projective combination synchronization scheme among identical chaotic generalized Lotka-Volterra three species biological systems using active control design. We consider here generalized Lotka-Volterra system containing two predators and one prey population existing in nature. An active control design is investigated which is essentially based on Lyapunov stability theory. The considered technique derives the global asymptotic stability using hybrid projective combination synchronization technique. In addition, the presented simulation outcomes and graphical results illustrate the validation of our proposed scheme. Prominently, both the analytical and computational results agree excellently. Comparisons versus others strategies exhibiting our proposed technique …


Fuzzy Solutions To Second Order Three Point Boundary Value Problem, Dimplekumar N. Chalishajar, R. Ramesh Dec 2020

Fuzzy Solutions To Second Order Three Point Boundary Value Problem, Dimplekumar N. Chalishajar, R. Ramesh

Applications and Applied Mathematics: An International Journal (AAM)

In this manuscript, the proposed work is to study the existence of second-order differential equations with three point boundary conditions. Existence is proved using fuzzy set valued mappings of a real variable whose values are normal, convex, upper semi continuous and compactly supported fuzzy sets. The sufficient conditions are also provided to establish the existence results of fuzzy solutions of second order differential equations for three point boundary value problem. By using Banach fixed point principle, a new existence theorem of solutions for these equations in the metric space of normal fuzzy convex sets with distance given by the maximum …


Sum Of Cubes Of The First N Integers, Obiamaka L. Agu Dec 2020

Sum Of Cubes Of The First N Integers, Obiamaka L. Agu

Electronic Theses, Projects, and Dissertations

In Calculus we learned that 􏰅Sum^{n}_{k=1} k = [n(n+1)]/2 , that Sum^{􏰅n}_{k=1} k^2 = [n(n+1)(2n+1)]/6 , and that Sum^{n}_{k=1} k^{3} = (n(n+1)/2)^{2}. These formulas are useful when solving for the area below quadratic or cubic function over an interval [a, b]. This tedious process, solving for areas under a quadratic or a cubic, served as motivation for the introduction of Riemman integrals. For the overzealous math student, these steps were replaced by a simpler method of evaluating antiderivatives at the endpoints a and b. From my recollection, a former instructor informed us to do the value of memorizing these formulas. …


Asymptotic Analysis Of Radial Point Rupture Solutions For Elliptic Equations, Attou Miloua Nov 2020

Asymptotic Analysis Of Radial Point Rupture Solutions For Elliptic Equations, Attou Miloua

Annual Symposium on Biomathematics and Ecology Education and Research

No abstract provided.


Personalized Immunotherapy Treatment Strategies For A System Of Chronic Myelogenous Leukemia, Paul Valle Nov 2020

Personalized Immunotherapy Treatment Strategies For A System Of Chronic Myelogenous Leukemia, Paul Valle

Annual Symposium on Biomathematics and Ecology Education and Research

No abstract provided.


Viewing Ode Models Through A New Lens: The Generalized Linear Chain Trick, Paul Hurtado, Cameron Richards Nov 2020

Viewing Ode Models Through A New Lens: The Generalized Linear Chain Trick, Paul Hurtado, Cameron Richards

Annual Symposium on Biomathematics and Ecology Education and Research

No abstract provided.


Applying Immuno-Epidemiology Principles To Violence, Anna H. Sisk, Nina H. Fefferman, Judy Day, Patricia Bamwine Nov 2020

Applying Immuno-Epidemiology Principles To Violence, Anna H. Sisk, Nina H. Fefferman, Judy Day, Patricia Bamwine

Annual Symposium on Biomathematics and Ecology Education and Research

No abstract provided.


Various Mathematical Models To Study Covid-19 Pandemic Dynamics With Quarantine, Hospitalized And Non-Pharmaceutical Interventions As Control Strategies, Amit Sharma, Bhanu Gupta Nov 2020

Various Mathematical Models To Study Covid-19 Pandemic Dynamics With Quarantine, Hospitalized And Non-Pharmaceutical Interventions As Control Strategies, Amit Sharma, Bhanu Gupta

Annual Symposium on Biomathematics and Ecology Education and Research

No abstract provided.


A Mathematical Model Illustrating Atherosclerotic Plaque Formation, Debasmita Mukherjee Nov 2020

A Mathematical Model Illustrating Atherosclerotic Plaque Formation, Debasmita Mukherjee

Annual Symposium on Biomathematics and Ecology Education and Research

No abstract provided.


Analyzing The Control Measures For The Homeless Population And Quantifying Their Impact On The Covid-19 Epidemic In New York City, Steven Manns Nov 2020

Analyzing The Control Measures For The Homeless Population And Quantifying Their Impact On The Covid-19 Epidemic In New York City, Steven Manns

Annual Symposium on Biomathematics and Ecology Education and Research

No abstract provided.


The Effect Of Fcgammariia Polymorphisms On Dengue Outbreak Severity, Leah Darwin, Richard V. Clarke Nov 2020

The Effect Of Fcgammariia Polymorphisms On Dengue Outbreak Severity, Leah Darwin, Richard V. Clarke

Annual Symposium on Biomathematics and Ecology Education and Research

No abstract provided.


Mathematical Modeling And Analysis Of The Zika Virus Epidemic With Human Mobility And Parameter Estimation For Localities In Puerto Rico, Carmen Caiseda Nov 2020

Mathematical Modeling And Analysis Of The Zika Virus Epidemic With Human Mobility And Parameter Estimation For Localities In Puerto Rico, Carmen Caiseda

Annual Symposium on Biomathematics and Ecology Education and Research

No abstract provided.


Modeling And Preparedness: The Transmission Dynamics Of Covid-19 Outbreak In Provinces Of Ecuador, Carlos E. Bustamante Orellana, Jordy Cevallos-Chavez, Cesar Montalvo, Jeff Sulliavan, Edwin Michael, Anuj Mubayi Nov 2020

Modeling And Preparedness: The Transmission Dynamics Of Covid-19 Outbreak In Provinces Of Ecuador, Carlos E. Bustamante Orellana, Jordy Cevallos-Chavez, Cesar Montalvo, Jeff Sulliavan, Edwin Michael, Anuj Mubayi

Annual Symposium on Biomathematics and Ecology Education and Research

No abstract provided.


A Regional Model For Projecting Covid-19 In Northern Mindanao, Philippines, Jayrold P. Arcede Nov 2020

A Regional Model For Projecting Covid-19 In Northern Mindanao, Philippines, Jayrold P. Arcede

Annual Symposium on Biomathematics and Ecology Education and Research

No abstract provided.


Mathematical Modeling Of Pancreatic Cancer With Clinical Data, Tuğba Akman Yıldız, Emek Köse, Samantha L. Elliott Nov 2020

Mathematical Modeling Of Pancreatic Cancer With Clinical Data, Tuğba Akman Yıldız, Emek Köse, Samantha L. Elliott

Annual Symposium on Biomathematics and Ecology Education and Research

No abstract provided.