Sökning: "nonlinear ordinary differential equations"
Visar resultat 1 - 5 av 6 uppsatser innehållade orden nonlinear ordinary differential equations.
1. An introduction to some ordinary differential equations governing stellar structures
Kandidat-uppsats, Lunds universitet/Matematik (naturvetenskapliga fakulteten)Sammanfattning : The Lane-Emden equation is a non-linear differential equation governing the equilibrium of polytropic stationary self-gravitating, spherically symmetric star models; $${\frac {1}{\xi ^{2}}}{\frac {d}{d\xi }}\left({\xi ^{2}{\frac {d\theta }{d\xi }}}\right)+\theta ^{n}=0.$$ In the isothermal cases we have the Chandrasekhar equation: $${\frac {1}{\xi ^{2}}}{\frac {d}{d\xi }}\left({\xi ^{2}{\frac {d\psi}{d\xi }}}\right)-e^{-\psi}=0$$ After having derived these models, we will go through all cases for which analytic solutions are achievable. LÄS MER
2. Symmetry methods and some nonlinear differential equations : Background and illustrative examples
Kandidat-uppsats, Karlstads universitet/Institutionen för matematik och datavetenskap (from 2013)Sammanfattning : Differential equations, in particular the nonlinear ones, are commonly used in formulating most of the fundamental laws of nature as well as many technological problems, among others. This makes the need for methods in finding closed form solutions to such equations all-important. LÄS MER
3. Simulation of Wastewater Treatment Plants Modeled by a System of Nonlinear Ordinary and Partial Differential Equations
Master-uppsats, Lunds universitet/Matematik LTHSammanfattning : Wastewater treatment consists of mechanical, chemical and biological purification. This master thesis concerns the biological part of the wastewater treatment called the activated sludge process (ASP). Two different mathematical models, one simplified and one complete, of the ASP are investigated. LÄS MER
4. Equivalence Group of Lie's Second-Order Equation of Type III
Master-uppsats, Blekinge Tekniska Högskola/Sektionen för ingenjörsvetenskapSammanfattning : Based on symmetry and invariance principles, Lie group analysis is the only systematic method for solving nonlinear differential equations analytically. Nonlinear second-order ordinary differential equations admitting two-dimensional Lie algebras can be transformed into one of the four types of canonical forms via Lie's integration method. LÄS MER
5. Study of the group properties of the Sircar-Papanicolaou model in case of a nonlinear utility function
Magister-uppsats, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE)Sammanfattning : In this paper it is considered the Sircar-Papanicolaou model wich takesinto account a feedback effect of dynamic hedging strategies of pro-gramme traders. Using the Lie group analysis we describe the symmetrygroup of the main equation of the concerned model. LÄS MER