Physical Sciences and Mathematics Commons^™

Determining Drug Dosage Using Calculus, Rajendra Dahal, Keith Bullard

Journal of the South Carolina Academy of Science

For most drugs, there is a concentration below for which the drug is ineffective and a concentration above for which the drug is dangerous. In this paper, we will study how the dosage and dosing intervals can be modified to ensure a safe, yet efficient level of the drug in the bloodstream using calculus. In particular, we will study the concentration of a drug over time and its dosing schedule.

New Oscillation Criteria For First-Order Differential Equations With General Delay Argument, Emad R. Attia, Irena Jadlovska

Turkish Journal of Mathematics

This paper is concerned with the oscillation of solutions to a class of first-order differential equations withvariable coefficients and a general delay argument. New oscillation criteria are established, which improve and extendmany known results reported in the literature. A couple of illustrative examples are given to show the efficiency of thenewly obtained results. In particular, it is shown that our criteria partially fulfill a remaining gap in a recent sharp resultby Pituk et al. [31].

Laguerre Type Twice-Iterated Appell Polynomials, Nesli̇han Bi̇ri̇ci̇k, Mehmet Ali̇ Özarslan, Bayram Çeki̇m

Turkish Journal of Mathematics

In this study, we use discrete Appell convolution to define the sequence of Laguerre type twice-iterated Appell polynomials. We obtain explicit representation, recurrence relation, determinantal representation, lowering operator, integro-partial raising operator and integro-partial differential equation. In addition, the special cases of this new family are investigated using Euler and Bernoulli numbers. We also state their corresponding characteristic properties.

New Effective Transformational Computational Methods, Jun Zhang, Ruzong Fan, Fangyang Shen, Junyi Tu

Publications and Research

Mathematics serves as a fundamental intelligent theoretic basis for computation, and mathematical analysis is very useful to develop computational methods to solve various problems in science and engineering. Integral transforms such as Laplace Transform have been playing an important role in computational methods. In this paper, we will introduce Sumudu Transform in a new computational approach, in which effective computational methods will be developed and implemented. Such computational methods are straightforward to understand, but powerful to incorporate into computational science to solve different problems automatically. We will provide computational analysis and essentiality by surveying and summarizing some related recent works, …

Raising Student Awareness Of Environmental Issues Via Writing Assignments With Differential Equations, Michelle L. Ghrist

CODEE Journal

In this paper, I discuss two environmentally-focused writing assignments that I developed and implemented in recent integral calculus and differential equations courses. These models of carbon storage and PCB’s in a river provide interesting applications of one-compartment mixing problems. The assignments were intended to focus student attention on sustainability concerns while also developing other essential skills. I discuss these assignments and their effect on my students’ technical writing and environmental awareness. Detailed introductory instructions and mostly complete solutions to these assignments appear in the appendices, to include sample student work.

From Big Farm To Big Pharma: A Differential Equations Model Of Antibiotic-Resistant Salmonella In Industrial Poultry Populations, Rilyn Mckallip

Honors Theses

Antibiotics are used in poultry production as prophylaxis, curative treatment, and growth promotion. The first use is as prophylaxis, or prevention of common bacterial diseases. The crowded conditions in concentrated animal feeding operations necessitate management of infectious disease to ensure overall animal health and the profitability of such operations. In these farms, between 20,000 and 125,000 birds are raised in shed-like enclosures [3], with an average of less than one square foot of space per chicken [34]. Antibiotics are currently used in chicken farms to manage and prevent common bacterial diseases such as respiratory and digestive tract infections, as well …

Lecture Note On Delay Differential Equation, Wenfeng Liu

Undergraduate Student Research Internships Conference

Delay differential equation is an important field in applied mathematics since it concerns more situations than the ordinary differential equation. Moreover, it makes the equations more applicable to the object's movement in real life.

My project is the lecture note on the delay differential equation provides a basic introduction to the delay differential equation, its application in real life, improving the ordinary differential equation, the primary method and definition for solving the delay differential equation and the use of the way in the ordinary differential equation to estimate the periodic solution to the delay differential equation.

Scattering Theory Of The Quadratic Eigenparameter Depending Impulsive Sturm-Liouville Equations, Güler Başak Öznur, Elgi̇z Bairamov

Turkish Journal of Mathematics

We handle an impulsive Sturm-Liouville boundary value problem. We find the Jost solution, Jost function, and scattering function of this problem and examine the properties of scattering function. We also study eigenvalues and resolvent operator of this problem. Finally, we exemplify our work by taking a different problem.

Numerical Study Of The Process Of Unsteady Filtration Of A Fluid In Interacting Porous Pressure Layers, Normakhmad Ravshanov, Elmira Nazirova, Sabur Aminov

Bulletin of TUIT: Management and Communication Technologies

A review of the fundamental studies conducted in 2010 - 2020 is given in the article to develop a mathematical model related to the fluid and gas filtration processes in porous media. To conduct a comprehensive study of the process of unsteady filtration of fluid in multi-layer porous pressure media and to make a management decision, a mathematical model described by a system of partial differential equations with corresponding initial and boundary conditions and a conservative numerical algorithm were developed. On the basis of the developed software of the problem posed, computational experiments were conducted on a computer; the calculation …

Modeling And Analysis Of Nonstationary Gas Filtration Under Gas Dynamic Parameters Variation, N Ravshanov, Elmira Nazirova

Bulletin of TUIT: Management and Communication Technologies

A mathematical model that describes a partial differential equation with boundary, internal and initial conditions was developed in the article, to study the gas-dynamic parameters of the gas filtration process in a porous medium under isothermal conditions. The study was performed based on the reviews of research works related to mathematical modeling in recent years. Computational experiments (CE) were conducted on a computer to determine the response of the main parameters on the process of gas filtration in a porous medium on the basis of the developed mathematical tool (model, numerical algorithm, and software). The results of numerical calculations were …

Cartan’S Approach To Second Order Ordinary Differential Equations, Paul Bracken

School of Mathematical and Statistical Sciences Faculty Publications and Presentations

In his work on projective connections, Cartan discusses his theory of second order differential equations. It is the aim here to look at how a normal projective connection can be constructed and how it relates to the geometry of a single second order differential equation. The calculations are presented in some detail in order to highlight the use of gauge conditions

Classifying Flow-Kick Equilibria: Reactivity And Transient Behavior In The Variational Equation, Alanna Haslam

Honors Projects

In light of concerns about climate change, there is interest in how sustainable management can maintain the resilience of ecosystems. We use flow-kick dynamical systems to model ecosystems subject to a constant kick occurring every τ time units. We classify the stability of flow-kick equilibria to determine which management strategies result in desirable long-term characteristics. To classify the stability of a flow-kick equilibrium, we classify the linearization of the time-τ map given by the time-τ map of the variational equation about the equilibrium trajectory. Since the variational equation is a non-autonomous linear differential equation, we conjecture that the asymptotic stability …

The Relation Between The Existence Of Bounded Global Solutions Of The Differential Equations And Equations On Time Scales, Olha Karpenko, Oleksandr Stanzhytskyi, Tetiana Dobrodzii

Turkish Journal of Mathematics

This work is devoted to the study of existence of a bounded solution of the differential equation, defined on a family of time scales $\mathbb{T}_\lambda$, provided the graininess function $\mu_\lambda$ converges to zero as $\lambda\to 0$. We obtained the conditions, under which the existence of a bounded solution of differential equation implies the existence of a bounded solution of the corresponding equation, defined on time scales, and vice versa.

Closed-Form Probability Distribution Of Number Of Infections At A Given Time In A Stochastic Sis Epidemic Model, Olusegun M. Otunuga

Olusegun Michael Otunuga

We study the effects of external fluctuations in the transmission rate of certain diseases and how these affect the distribution of the number of infected individuals over time. To do this, we introduce random noise in the transmission rate in a deterministic SIS model and study how the number of infections changes over time. The objective of this work is to derive and analyze the closed form probability distribution of the number of infections at a given time in the resulting stochastic SIS epidemic model. Using the Fokker-Planck equation, we reduce the differential equation governing the number of infections to …

Closed-Form Probability Distribution Of Number Of Infections At A Given Time In A Stochastic Sis Epidemic Model, Olusegun M. Otunuga

Mathematics Faculty Research

We study the effects of external fluctuations in the transmission rate of certain diseases and how these affect the distribution of the number of infected individuals over time. To do this, we introduce random noise in the transmission rate in a deterministic SIS model and study how the number of infections changes over time. The objective of this work is to derive and analyze the closed form probability distribution of the number of infections at a given time in the resulting stochastic SIS epidemic model. Using the Fokker-Planck equation, we reduce the differential equation governing the number of infections to …

Problem With Bitsadze-Samarski And Integral Conditions For An Ordinary Differential Equation, M. Abdumannopov

Scientific journal of the Fergana State University

In the paper, a problem with Bitsadze-Samarski condition and first-type integral condition for the second order ordinary differential equation is studied.

Problem With Bitsadze-Samarski And Integral Conditions For An Ordinary Differential Equation, M. Abdumannopov

Scientific journal of the Fergana State University

In the paper, a problem with Bitsadze-Samarski condition and first-type integral condition for the second order ordinary differential equation is studied.

Batik Dying Simulation Based On Diffusion, Yangtao Yu, Zhenlu Yu, Wenhua Qian, Keshi Zhang, Xu Dan

Journal of System Simulation

Abstract: This paper presents a three-layer model which is composed of wax layer, warp layer and weft layer. The wax layer wraps warp and weft layer which overlap together. According to Fick's second law and considering dye's diffusion, absorption and supply, a differential equation is built to describe diffusion process and this equation is discretized. Porosity, tortuosity and neighboring coefficient are used in the equation. Rectangular weave is simulated by using ellipse-distance model and blurred in HSV color space. Simulation shows that the satisfactory visual effect which closes to real batik cloth is acquired by the method and the algorithm …

An Intrinsic Characterization Of Bonnet Surfaces Based On A Closed Differential Ideal, Paul Bracken

School of Mathematical and Statistical Sciences Faculty Publications and Presentations

The structure equations for a two-dimensional manifold are introduced and two results based on the Codazzi equations pertinent to the study of isometric surfaces are obtained from them. Important theorems pertaining to isometric surfaces are stated and a theorem due to Bonnet is obtained. A transformation for the connection forms is developed. It is proved that the angle of deformation must be harmonic, and that the differentials of many of the important variables generate a closed differential ideal. This implies that a coordinate system exists in which many of the variables satisfy particular ordinary differential equations, and these results can …

A Two Host Species Stage-Structured Model Of West Nile Virus Transmission, Taylor A. Beebe

Theses and Dissertations

We develop and evaluate a novel host-vector model of West Nile virus (WNV) transmission that incorporates multiple avian host species and host stage-structure (juvenile and adult stages), with both species-specific and stage-specific biting rates of vectors on hosts. We use this model to explore WNV transmission dynamics that occur between vectors and multiple structured host populations as a result of heterogeneous biting rates. Our analysis shows that increased exposure of juvenile hosts results in earlier, more intense WNV transmission when compared to the effects of differential host species exposure, regardless of other parameter values. We also find that, in addition …

Solving The Differential Equation For The Probit Function Using A Variant Of The Carleman Embedding Technique., Kelechukwu Iroajanma Alu

Electronic Theses and Dissertations

The probit function is the inverse of the cumulative distribution function associated with the standard normal distribution. It is of great utility in statistical modelling. The Carleman embedding technique has been shown to be effective in solving first order and, less efficiently, second order nonlinear differential equations. In this thesis, we show that solutions to the second order nonlinear differential equation for the probit function can be approximated efficiently using a variant of the Carleman embedding technique.

Statistical Models For Environmental And Health Sciences, Yong Xu

USF Tampa Graduate Theses and Dissertations

Statistical analysis and modeling are useful for understanding the behavior of different phenomena. In this study we will focus on two areas of applications: Global warming and cancer research. Global Warming is one of the major environmental challenge people face nowadays and cancer is one of the major health problem that people need to solve.

For Global Warming, we are interest to do research on two major contributable variables: Carbon dioxide (CO2) and atmosphere temperature. We will model carbon dioxide in the atmosphere data with a system of differential equations. We will develop a differential equation for each of six …

Establishment Of A Chebyshev-Dependent Inhomogeneous Second Order Differential Equation For The Applied Physics-Related Boubaker-Turki Polynomials, Micahel Dada, O. Bamidele Awojoyogbe, Maximilian Hasler, Karem B. Ben Mahmoud, Amine Bannour

Applications and Applied Mathematics: An International Journal (AAM)

This paper proposes Chebyshev-dependent inhomogeneous second order differential equation for the m-Boubaker polynomials (or Boubaker-Turki polynomials). This differential equation is also presented as a guide to applied physics studies. A concrete example is given through an attempt to solve the Bloch NMR flow equation inside blood vessels.

Stability Analysis Of Systems Of Difference Equations, Richard A. Clinger

Theses and Dissertations

Difference equations are the discrete analogs to differential equations. While the independent variable of differential equations normally is a continuous time variable, t, that of a difference equation is a discrete time variable, n, which measures time in intervals. A feature of difference equations not shared by differential equations is that they can be characterized as recursive functions. Examples of their use include modeling population changes from one season to another, modeling the spread of disease, modeling various business phenomena, discrete simulations applications, or giving rise to the phenomena chaos. The key is that they are discrete, recursive relations. Systems …

Asymptotic Integration Of A Perturbed Constant Coefficient Differential Equation Under Mild Integral Smallness Conditions, William F. Trench

William F. Trench

No abstract provided.

Existence Of Global Solutions With Prescribed Asymptotic Behavior For Nonlinear Differential Equations, William F. Trench

William F. Trench

No abstract provided.

Sobolev Type Differential Equations, M. E. Lord, V. Lakshmikantham

Mathematics Technical Papers

An imbedding method for solving linear Fredholm integral equations was introduced by Sobolev [3] which involves the solution of the following differential equation with initial value for the resolvent kernel [see pdf for notation]. The differential equation in (1.1) is unusual in that the solution K(t,y,x) is evaluated at different combinations of the independent variables (t,y,x) . We will refer to any differential equation with this property as a Sobolev type differential equation. We introduce a Sobolev type differential equation which generalizes (1.1) and consider conditions for existence and uniqueness. A Picard type theorem is obtained, which by way of …

On The Existence Of Solutions Of Differential Equations In A Banach Space, Jerome Eisenfeld, V. Lakshmikantham

Mathematics Technical Papers

The study of Cauchy problem for differential equations in a Banach space has taken two different directions. One approach is to find compactness type conditions [1,2,4,9,14] to guarantee existence of solutions only and the corresponding results are extensions of the classical Peano's Theorem. The other approach is to employ accretive type conditions [9,10,11,12,15] which assure existence as well as uniqueness of solutions. In fact, this latter technic shows that uniqueness conditions imply existence of solutions [16]. In this paper we follow the first direction. Employing Lyapunov-like functions and the notion of the measure of noncompactness, we prove a local existence …

On A Boundary Value Problem For A Class Of Differential Equations With A Deviating Argument, V. Lakshmikantham, Jerome Eisenfeld

Mathematics Technical Papers

Recently, J. Chandra [1] obtained comparison estimates for differential equations with deviating argument (1) [see pdf for notation] on the interval I: to [see pdf for notation] , where [see pdf for notation] is a given continuous function defined on a suitable interval (containing I ), together with the boundary conditions (2) [see pdf for notation] for [see pdf for notation] The class of BVP (1) - (2) is incorporated in a larger class discussed in [3]. The introduction in [1] of a maximal solution has furnished comparison results and an iterative procedure for obtaining solutions. The use of the …