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Full-Text Articles in Applied Mathematics

Finding Positive Solutions Of Boundary Value Dynamic Equations On Time Scale, Olusegun Michael Otunuga Feb 2019

Finding Positive Solutions Of Boundary Value Dynamic Equations On Time Scale, Olusegun Michael Otunuga

Olusegun Michael Otunuga

This thesis is on the study of dynamic equations on time scale. Most often, the derivatives and anti-derivatives of functions are taken on the domain of real numbers, which cannot be used to solve some models like insect populations that are continuous while in season and then follow a difference scheme with variable step-size. They die out in winter, while the eggs are incubating or dormant; and then they hatch in a new season, giving rise to a non overlapping population. The general idea of my thesis is to find the conditions for having a positive solution of any boundary …


Call For Abstracts - Resrb 2019, July 8-9, Wrocław, Poland, Wojciech M. Budzianowski Dec 2018

Call For Abstracts - Resrb 2019, July 8-9, Wrocław, Poland, Wojciech M. Budzianowski

Wojciech Budzianowski

No abstract provided.


Homogenization In Perforated Domains And With Soft Inclusions, Brandon C. Russell Apr 2018

Homogenization In Perforated Domains And With Soft Inclusions, Brandon C. Russell

Brandon Russell

In this dissertation, we first provide a short introduction to qualitative homogenization of elliptic equations and systems. We collect relevant and known results regarding elliptic equations and systems with rapidly oscillating, periodic coefficients, which is the classical setting in homogenization of elliptic equations and systems. We extend several classical results to the so-called case of perforated domains and consider materials reinforced with soft inclusions. We establish quantitative H^1-convergence rates in both settings, and as a result deduce large-scale Lipschitz estimates and Liouville-type estimates for solutions to elliptic systems with rapidly oscillating, periodic, bounded, and measurable coefficients. Finally, we connect these …


A Discontinuous Galerkin Method For Unsteady Two-Dimensional Convective Flows, Andreas C. Aristotelous, N. C. Papanicolaou Feb 2017

A Discontinuous Galerkin Method For Unsteady Two-Dimensional Convective Flows, Andreas C. Aristotelous, N. C. Papanicolaou

Andreas Aristotelous

We develop a High-Order Symmetric Interior Penalty (SIP) Discontinuous Galerkin (DG) Finite Element Method (FEM) to investigate two-dimensional in space natural convective flows in a vertical cavity. The physical problem is modeled by a coupled nonlinear system of partial differential equations and admits various solutions including stable and unstable modes in the form of traveling and/or standing waves, depending on the governing parameters. These flows are characterized by steep boundary and internal layers which evolve with time and can be well-resolved by high-order methods that also are adept to adaptive meshing. The standard no-slip boundary conditions which apply on the …


Zespół Energii Odnawialnej I Zrównoważonego Rozwoju (Eozr), Wojciech M. Budzianowski Dec 2014

Zespół Energii Odnawialnej I Zrównoważonego Rozwoju (Eozr), Wojciech M. Budzianowski

Wojciech Budzianowski

No abstract provided.


Maxwell’S Equations On Cantor Sets: A Local Fractional Approach, Yang Xiaojun Nov 2013

Maxwell’S Equations On Cantor Sets: A Local Fractional Approach, Yang Xiaojun

Xiao-Jun Yang

Maxwell’s equations on Cantor sets are derived from the local fractional vector calculus. It is shown that Maxwell’s equations on Cantor sets in a fractal bounded domain give efficiency and accuracy for describing the fractal electric and magnetic fields. Local fractional differential forms of Maxwell’s equations on Cantor sets in the Cantorian and Cantor-type cylindrical coordinates are obtained. Maxwell’s equations on Cantor set with local fractional operators are the first step towards a unified theory of Maxwell’s equations for the dynamics of cold dark matter.


Weierstrass Traveling Wave Solutions For Dissipative Benjamin, Bona, And Mahony (Bbm) Equation, Stefan C. Mancas, Greg Spradlin, Harihar Khanal Jul 2013

Weierstrass Traveling Wave Solutions For Dissipative Benjamin, Bona, And Mahony (Bbm) Equation, Stefan C. Mancas, Greg Spradlin, Harihar Khanal

Gregory S. Spradlin

In this paper the effect of a small dissipation on waves is included to find exact solutions to the modified Benjamin, Bona, and Mahony (BBM) equation by viscosity. Using Lyapunov functions and dynamical systems theory, we prove that when viscosity is added to the BBM equation, in certain regions there still exist bounded traveling wave solutions in the form of solitary waves, periodic, and elliptic functions. By using the canonical form of Abel equation, the polynomial Appell invariant makes the equation integrable in terms of Weierstrass ℘ functions. We will use a general formalism based on Ince's transformation to write …


Helmholtz And Diffusion Equations Associated With Local Fractional Derivative Operators Involving The Cantorian And Cantor-Type Cylindrical Coordinates, Yang Xiaojun Jul 2013

Helmholtz And Diffusion Equations Associated With Local Fractional Derivative Operators Involving The Cantorian And Cantor-Type Cylindrical Coordinates, Yang Xiaojun

Xiao-Jun Yang

The main object of this paper is to investigate the Helmholtz and diffusion equations on the Cantor sets involving local fractional derivative operators. The Cantor-type cylindrical-coordinate method is applied to handle the corresponding local fractional differential equations. Two illustrative examples for the Helmholtz and diffusion equations on the Cantor sets are shown by making use of the Cantorian and Cantor-type cylindrical coordinates.


Fractal Heat Conduction Problem Solved By Local Fractional Variation Iteration Method, Yang Xiaojun Mar 2013

Fractal Heat Conduction Problem Solved By Local Fractional Variation Iteration Method, Yang Xiaojun

Xiao-Jun Yang

This paper points out a novel local fractional variational iteration method for processing the local fractional heat conduction equation arising in fractal heat transfer.


A Local Fractional Variational Iteration Method For Laplace Equation Within Local Fractional Operators, Xiao-Jun Yang Feb 2013

A Local Fractional Variational Iteration Method For Laplace Equation Within Local Fractional Operators, Xiao-Jun Yang

Xiao-Jun Yang

The local fractional variational iteration method for local fractional Laplace equation is investigated in this paper. The operators are described in the sense of local fractional operators.The obtained results reveal that the method is very effective.


Determination Of Kinetic Parameters From The Thermogravimetric Data Set Of Biomass Samples, Karol Postawa, Wojciech M. Budzianowski Dec 2012

Determination Of Kinetic Parameters From The Thermogravimetric Data Set Of Biomass Samples, Karol Postawa, Wojciech M. Budzianowski

Wojciech Budzianowski

This article describes methods of the determination of kinetic parameters from the thermogravimetric data set of biomass samples. It presents the methodology of the research, description of the needed equipment, and the method of analysis of thermogravimetric data. It describes both methodology of obtaining quantitative data such as kinetic parameters as well as of obtaining qualitative data like the composition of biomass. The study is focused mainly on plant biomass because it is easy in harvesting and preparation. Methodology is shown on the sample containing corn stover which is subsequently pyrolysed. The investigated sample show the kinetic of first order …


Multiple Periodic Solutions For A Nonlinear Suspension Bridge Equation, Lisa Humphreys, P. Mckenna Apr 2012

Multiple Periodic Solutions For A Nonlinear Suspension Bridge Equation, Lisa Humphreys, P. Mckenna

Lisa D Humphreys

We investigate nonlinear oscillations in a fourth-order partial differential equation which models a suspension bridge. Previous work establishes multiple periodic solutions when a parameter exceeds a certain eigenvalue. In this paper, we use Leray Schauder degree theory to prove that if the parameter is increased further, beyond a second eigenvalue, then additional solutions are created.


On The Influence Of Damping In Hyperbolic Equations With Parabolic Degeneracy, Ralph Saxton, Katarzyna Saxton Dec 2011

On The Influence Of Damping In Hyperbolic Equations With Parabolic Degeneracy, Ralph Saxton, Katarzyna Saxton

Ralph Saxton

This paper examines the effect of damping on a nonstrictly hyperbolic 2x2 system. It is shown that the growth of singularities is not restricted as in the strictly hyperbolic case where dissipation can be strong enough to preserve the smoothness of solutions globally in time. Here, irrespective of the stabilizing properties of damping, solutions are found to break down in finite time on a line where two eigenvalues coincide in state space.


Nonlinear Waves And Solitons On Contours And Closed Surfaces, Andrei Ludu Dec 2011

Nonlinear Waves And Solitons On Contours And Closed Surfaces, Andrei Ludu

Andrei Ludu

No abstract provided.


Hydrogen Production From Biogas By Oxy-Reforming: Reaction System Analysis, Aleksandra Terlecka, Wojciech M. Budzianowski Dec 2011

Hydrogen Production From Biogas By Oxy-Reforming: Reaction System Analysis, Aleksandra Terlecka, Wojciech M. Budzianowski

Wojciech Budzianowski

Oxy-reforming is emerging as an interesting alternative to conventional methods of hydrogen generation. The current article characterises this process through analysis of individual reactions: SMR (steam methane reforming), WGS (water gas shift) and CPO (catalytic partial oxidation). Analyses relate to optimisation of thermal conditions thus enabling cost-effectivenes of the process.


Multiple Soliton Solutions Of (2+1)-Dimensional Potential Kadomtsev-Petviashvili Equation, Mohammad Najafi M.Najafi, Ali Jamshidi Dec 2011

Multiple Soliton Solutions Of (2+1)-Dimensional Potential Kadomtsev-Petviashvili Equation, Mohammad Najafi M.Najafi, Ali Jamshidi

mohammad najafi

We employ the idea of Hirota’s bilinear method, to obtain some new exact soliton solutions for high nonlinear form of (2+1)-dimensional potential Kadomtsev-Petviashvili equation. Multiple singular soliton solutions were obtained by this method. Moreover, multiple singular soliton solutions were also derived.


Fractional Trigonometric Functions In Complex-Valued Space: Applications Of Complex Number To Local Fractional Calculus Of Complex Function, Yang Xiao-Jun Jun 2011

Fractional Trigonometric Functions In Complex-Valued Space: Applications Of Complex Number To Local Fractional Calculus Of Complex Function, Yang Xiao-Jun

Xiao-Jun Yang

This paper presents the fractional trigonometric functions in complex-valued space and proposes a short outline of local fractional calculus of complex function in fractal spaces.


The 1905 Einstein Equation In A General Mathematical Analysis Model Of Quasars, Byron E. Bell May 2010

The 1905 Einstein Equation In A General Mathematical Analysis Model Of Quasars, Byron E. Bell

Byron E. Bell

The 1905 wave equation of Albert Einstein is a model that can be used in many areas, such as physics, applied mathematics, statistics, quantum chaos and financial mathematics, etc. I will give a proof from the equation of A. Einstein’s paper “Zur Elektrodynamik bewegter Körper” it will be done by removing the variable time (t) and the constant (c) the speed of light from the above equation and look at the factors that affect the model in a real analysis framework. Testing the model with SDSS-DR5 Quasar Catalog (Schneider +, 2007). Keywords: direction cosine, apparent magnitudes of optical light; ultraviolet …


The 1905 Einstein Equation In A General Mathematical Analysis Model Of Quasars, Byron E. Bell Dec 2009

The 1905 Einstein Equation In A General Mathematical Analysis Model Of Quasars, Byron E. Bell

Byron E. Bell

No abstract provided.


Design And Cfd Analysis Of Mass Transfer And Shear Stresses Distributions In Airlift Reactor, Rachid Bannari, Brahim Selma, Abdelfettah Bannari, Pierre Proulx Jun 2009

Design And Cfd Analysis Of Mass Transfer And Shear Stresses Distributions In Airlift Reactor, Rachid Bannari, Brahim Selma, Abdelfettah Bannari, Pierre Proulx

Rachid BANNARI

The design, scale-up and performance evaluation of biological reactors require accurate information about the gas-liquid flow dynamics. In this study, we use CFD techniques to investigate important parameters of the multiphase flow dynamics on an initial airlift bioreactor in order to improve its design. Such parameters are distributions of shear stresses and mass transfer. Our initial proposed design of the airlift bioreactor was used for biomass growing. Specifically to produce cellulase enzyme using the fungus Trichoderma Reesei. However, the morphology of the microorganism obtained in this bioreactor was not appropriated to produce cellulase. Since the microorganism morphology presented a small …


Problems Of Local Fractional Definite Integral Of The One-Variable Non-Differentiable Function, Yang Xiao-Jun Dec 2008

Problems Of Local Fractional Definite Integral Of The One-Variable Non-Differentiable Function, Yang Xiao-Jun

Xiao-Jun Yang

It is proposed that local fractional calculas introduced by Kolwankar and Gangal is extended by the concept of Jumarie’s fractional calculus and local fractional definite integral is redefined. The properties and the theorems of local fractional calculus are discussed in this paper.


Lanchester's Equations In Three Dimensions, Christina Spradlin, Greg Spradlin Mar 2007

Lanchester's Equations In Three Dimensions, Christina Spradlin, Greg Spradlin

Gregory S. Spradlin

This paper generalizes Lanchester's equations of warfare to partial differential equations involving time and two spatial variables. Unlike in Lanchester's original ordinary differential equations, the distribution of armies over the battlefield must be considered. Four different modes of attack are introduced, generalizing Lanchester's equations for area fire and for direct fire. The effect of the distribution of forces and their movement on the outcome is considered, and numerical simulations given.


A Mathematical Regression Of The U.S. Gross Private Domestic Investment 1959-2001, Byron E. Bell Sep 2006

A Mathematical Regression Of The U.S. Gross Private Domestic Investment 1959-2001, Byron E. Bell

Byron E. Bell

SUMMARY OF PROJECT What did I do? A study of the role the U.S. stock markets and money markets have possibly played in the Gross Private Domestic Investment (GPDI) of the United States from the year 1959 to the year 2001 and I created a Multiple Linear Regression Model (MLRM).


Crisp Solution Of A General Fuzzy Linear System, S. Abbasbandy, R. Ezzati Dec 2005

Crisp Solution Of A General Fuzzy Linear System, S. Abbasbandy, R. Ezzati

Saeid Abbasbandy

In this paper a method for solving a general fuzzy linear system with crisp solution is considered. We consider the method in special case when the elements of the coefficient matrix and the right hand side are trapezoidal fuzzy numbers. The method in detail is discussed and followed by theorem and illustrated by solving some examples.


Analysis And Classification Of Nonlinear Dispersive Evolution Equations In The Potential Representation, Andrei Ludu Dec 2001

Analysis And Classification Of Nonlinear Dispersive Evolution Equations In The Potential Representation, Andrei Ludu

Andrei Ludu

No abstract provided.


An Elliptic Equation With Spike Solutions Concentrating At Local Minima Of The Laplacian Of The Potential, Gregory S. Spradlin Dec 1999

An Elliptic Equation With Spike Solutions Concentrating At Local Minima Of The Laplacian Of The Potential, Gregory S. Spradlin

Gregory S. Spradlin

We consider a singularly perturbed elliptic PDE that arises in the study of nonlinear Schrodinger equations. We seek solutions that are positive on the entirety of Euclidean space and that vanish at infinity. Under the assumption that the nonlinear term of the PDE satisfies super-linear and sub-critical growth conditions, we show that for small values of the epsilon parameter in the PDE, there solutions that concentrate near local minima of V (a coefficient function in the PDE) . The local minima may occur in unbounded components, as long as the Laplacian of V achieves a strict local minimum along such …


Generalization Kdv Equation For Fluid Dynamics And Quantum Algebras, Andrei Ludu Dec 1995

Generalization Kdv Equation For Fluid Dynamics And Quantum Algebras, Andrei Ludu

Andrei Ludu

No abstract provided.


An Augmented Galerkin Algorithms For First Kind Integral Equations Of Hammerstein Type, S. Abbasbandy, E. Babolian Dec 1995

An Augmented Galerkin Algorithms For First Kind Integral Equations Of Hammerstein Type, S. Abbasbandy, E. Babolian

Saeid Abbasbandy

Recent papers, [1],[2] & [3], describe some algorithms for linear first kind integral equations. These algorithms are based on augmented Galerkin method and Cross-validation scheme [5]. The results show that, these algorithms work well for linear equations. In this paper we apply algorithms of [1] & [2] on non-linear first kind integral equations of Hammerstein type with bounded solution. In order to obtain a posteriori error estimate, we apply fifteen-point Gauss-Kronrod quadrature rule [4]. Finally, we give a number of numerical examples showing that the algorithms work well in practice.


Sliding Mode Control Of The Systems With Uncertain Direction Of Control Vector, Sergey V. Drakunov Dec 1992

Sliding Mode Control Of The Systems With Uncertain Direction Of Control Vector, Sergey V. Drakunov

Sergey V. Drakunov

No abstract provided.


Sliding-Mode Observers Based On Equivalent Control Method, Sergey V. Drakunov Dec 1991

Sliding-Mode Observers Based On Equivalent Control Method, Sergey V. Drakunov

Sergey V. Drakunov

No abstract provided.