|
|
Mathematical modeling of population problems in biology
Čampulová, Martina ; Opluštil, Zdeněk (referee) ; Čermák, Jan (advisor)
This bachelor´s thesis deals with the modeling of population problems in biology. The aim of this thesis is to mention some basic models describing dynamics of the evolution of one or two populations. Models mentioned in this thesis are described by first-order ordinary differential equations. Exploring the evolution of the population brings the main question - searching for singular points (and verifying their stability) of differential equations describing the evolution of the population. Therefore the thesis also deals with these problems.
|
|
|
Duffing equation in mathematical modelling of non-linear oscillators
Vozárová, Juliana ; Štoudková Růžičková, Viera (referee) ; Šremr, Jiří (advisor)
The thesis deals with the behaviour of non-linear oscilators. Within their models there often appears the Duffing equation. The aims of this investigation include fundamentals of the theory of differential equations, interpretation of the Duffing equation and its analysis. To fulfill these aims, this investigation utilizes qualitative theory of the differential equations. It means that closed form solutions to the equations are not looked for but qualitative behaviour and properties of the solutions are studied. Some of the properties of solutions can be obtained from phase portraits.
|
|
|
Duffing equation in mathematical modelling of non-linear oscillators
Vozárová, Juliana ; Štoudková Růžičková, Viera (referee) ; Šremr, Jiří (advisor)
The thesis deals with the behaviour of non-linear oscilators. Within their models there often appears the Duffing equation. The aims of this investigation include fundamentals of the theory of differential equations, interpretation of the Duffing equation and its analysis. To fulfill these aims, this investigation utilizes qualitative theory of the differential equations. It means that closed form solutions to the equations are not looked for but qualitative behaviour and properties of the solutions are studied. Some of the properties of solutions can be obtained from phase portraits.
|
|
|
Singular Behavior of the Hartree-Fock Equations
Uhlířová, Tereza ; Zamastil, Jaroslav (advisor) ; Čížek, Martin (referee)
The non-linear Hartree-Fock (HF) equations are usually solved via the iterative self-consistent field method. However, there is no a priori guarantee of convergence, especially in systems with strong electron correlation where symmetry breaking occurs. This work focuses on closed- shell systems in the HF approximation and the (in)stability of the found solutions, and proposes new deterministic methods for the localization of both symmetry-adapted and broken symmetry solutions. We employ a perturbative method and show how one can always obtain a symmetry-adapted solution of the HF equations. We also determine the radius of convergence, related to the existence of at least one bound state, of the perturbative series. Next, we rederive the matrix of stability and adapt it to spin and orbital symmetry. Calculation of higher energy variations follows, first in terms of spin-orbitals and then orbitals. Motivated by the investigation of the structure of a broken-symmetry solution, we propose a new deterministic method for the localization of a broken-symmetry solution. The general expressions are verified by reformulating the stability conditions for simple cases. The proposed methods are successfully applied to helium-, beryllium- and neon-like systems.
|
|
|
Mathematical modeling of population problems in biology
Čampulová, Martina ; Opluštil, Zdeněk (referee) ; Čermák, Jan (advisor)
This bachelor´s thesis deals with the modeling of population problems in biology. The aim of this thesis is to mention some basic models describing dynamics of the evolution of one or two populations. Models mentioned in this thesis are described by first-order ordinary differential equations. Exploring the evolution of the population brings the main question - searching for singular points (and verifying their stability) of differential equations describing the evolution of the population. Therefore the thesis also deals with these problems.
|
guest ::
