Zobrazeno 1 - 10
of 122
pro vyhledávání: '"Nikolay K. Vitanov"'
Publikováno v:
Mathematics, Vol 12, Iss 13, p 1984 (2024)
We discuss a mathematical model of motion of substance in a node of a network which has a structure consisting of a chain of cells. An exact solution for the model equations is obtained in the case when the structure of the node is a chain of two cel
Externí odkaz:
https://doaj.org/article/98de03d41f064f0e9706081601e5b05d
Autor:
Nikolay K. Vitanov
Publikováno v:
Axioms, Vol 12, Iss 12, p 1106 (2023)
Transformations are much used to connect complicated nonlinear differential equations to simple equations with known exact solutions. Two examples of this are the Hopf–Cole transformation and the simple equations method. In this article, we follow
Externí odkaz:
https://doaj.org/article/4717128047454bfeaf0b9778eba6782a
Publikováno v:
Entropy, Vol 26, Iss 1, p 5 (2023)
We discuss the spread of a piece of news in a population. This is modeled by SIR model of epidemic spread. The model can be reduced to a nonlinear differential equation for the number of people affected by the news of interest. The differential equat
Externí odkaz:
https://doaj.org/article/d6a30737315f4ed897ef2abd29e196f6
Publikováno v:
Computation, Vol 11, Iss 7, p 129 (2023)
We studied obtaining exact solutions to a set of equations related to the SEIR (Susceptible-Exposed-Infectious-Recovered) model of epidemic spread. These solutions may be used to model epidemic waves. We transformed the SEIR model into a differential
Externí odkaz:
https://doaj.org/article/fb87823e00d04690b8d8eebe0e2d507c
Autor:
Nikolay K. Vitanov, Kaloyan N. Vitanov
Publikováno v:
Entropy, Vol 25, Iss 3, p 438 (2023)
The SIR model of epidemic spreading can be reduced to a nonlinear differential equation with an exponential nonlinearity. This differential equation can be approximated by a sequence of nonlinear differential equations with polynomial nonlinearities.
Externí odkaz:
https://doaj.org/article/1b2cfbd114e748d8a657a9f135fd0ca5
Autor:
Nikolay K. Vitanov
Publikováno v:
Entropy, Vol 24, Iss 11, p 1653 (2022)
Exact solutions of nonlinear differential equations are of great importance to the theory and practice of complex systems. The main point of this review article is to discuss a specific methodology for obtaining such exact solutions. The methodology
Externí odkaz:
https://doaj.org/article/37f1150bcadf4cb58743d8d1ff39c7ec
Publikováno v:
Entropy, Vol 23, Iss 12, p 1624 (2021)
We discuss the application of the Simple Equations Method (SEsM) for obtaining exact solutions of non-linear differential equations to several cases of equations containing non-polynomial non-linearity. The main idea of the study is to use an appropr
Externí odkaz:
https://doaj.org/article/ee4615c67ecb4d5db051fa815eb886af
Publikováno v:
Computation, Vol 9, Iss 10, p 104 (2021)
We discuss the Simple Equations Method (SEsM) for obtaining exact solutions of a class of nonlinear differential equations containing polynomial nonlinearities. We present an amended version of the methodology, which is based on the use of composite
Externí odkaz:
https://doaj.org/article/8aa7f3c7e07345bda6db2a2f1fdd2b40
Publikováno v:
Entropy, Vol 23, Iss 1, p 10 (2020)
The goal of this article is to discuss the Simple Equations Method (SEsM) for obtaining exact solutions of nonlinear partial differential equations and to show that several well-known methods for obtaining exact solutions of such equations are connec
Externí odkaz:
https://doaj.org/article/2fba7f2acfe847a6a5e5f364a80cd2ce
Autor:
Elena V. Nikolova, Nikolay K. Vitanov
Publikováno v:
Entropy, Vol 22, Iss 12, p 1388 (2020)
In this study we extend a model, proposed by Dendrinos, which describes dynamics of change of influence in a social system containing a public sector and a private sector. The novelty is that we reconfigure the system and consider a system consisting
Externí odkaz:
https://doaj.org/article/cbb923ce64a1414fb32a35cc49f808d5