Zobrazeno 1 - 10
of 180
pro vyhledávání: '"Radu Precup"'
Autor:
Alexandru Hofman, Radu Precup
Publikováno v:
Mathematical Modelling and Control, Vol 2, Iss 3, Pp 90-99 (2022)
The paper deals with some control problems related to the Kolmogorov system for two interacting populations. For the first problem, the control acts in time over the per capita growth rates of the two populations in order for the ratio between their
Externí odkaz:
https://doaj.org/article/7f8b24f81cfc46e8a03784dbeba36f69
Publikováno v:
Electronic Journal of Qualitative Theory of Differential Equations, Vol 2022, Iss 47, Pp 1-22 (2022)
The paper deals with the existence and localization of positive radial solutions for stationary partial differential equations involving a general $\phi $-Laplace operator in the annulus. Three sets of boundary conditions are considered: Dirichlet–
Externí odkaz:
https://doaj.org/article/bd6c1acf59ea4c38b2fb7aaedb2b4ab8
Autor:
Radu Precup, Andrei Stan
Publikováno v:
AIMS Mathematics, Vol 7, Iss 8, Pp 15258-15281 (2022)
In this paper, the operator approach based on the fixed point principles of Banach and Schaefer is used to establish the existence of solutions to stationary Kirchhoff equations with reaction terms. Next, for a coupled system of Kirchhoff equations,
Externí odkaz:
https://doaj.org/article/e787cda1e8ef45738af5e7acee072603
Publikováno v:
Mathematical Biosciences and Engineering, Vol 18, Iss 2, Pp 1845-1863 (2021)
A complete stability analysis of the equilibrium solutions of a system modeling tumor chemotherapy is performed in two cases of administration of the treatment, by continuous infusion and by periodic infusion. Several numerical simulations illustrate
Externí odkaz:
https://doaj.org/article/66f3503f9c86410f98de93f2b21943c7
Autor:
Radu Precup
Publikováno v:
Electronic Journal of Qualitative Theory of Differential Equations, Vol 2020, Iss 87, Pp 1-9 (2020)
Existence of solutions to the Dirichlet problem for implicit elliptic equations is established by using Krasnoselskii–Schaefer type theorems owed to Burton–Kirk and Gao–Li–Zhang. The nonlinearity of the equations splits into two terms: one te
Externí odkaz:
https://doaj.org/article/f0f1d4855baf4bad81e7c80362bcd4ec
Autor:
Radu Precup
Publikováno v:
Results in Applied Mathematics, Vol 13, Iss , Pp 100236- (2022)
The aim of this paper is to draw attention to a general principle for solving control problems for operator equations with the help of fixed point techniques. Three distinct applications are presented: a control problem related to the Lotka–Volterr
Externí odkaz:
https://doaj.org/article/24587caa95ec4f5f96439126fcb27405
Publikováno v:
Symmetry, Vol 13, Iss 10, p 1867 (2021)
In this paper, two control problems for a symmetric model of cell dynamics related to leukemia are considered. The first one, in connection with classical chemotherapy, is that the evolution of the disease under treatment should follow a prescribed t
Externí odkaz:
https://doaj.org/article/9e2357aa931e45b981cd6335fdf2181d
Autor:
Vlad Moisoiu, Patric Teodorescu, Lorand Parajdi, Sergiu Pasca, Mihnea Zdrenghea, Delia Dima, Radu Precup, Ciprian Tomuleasa, Simona Soverini
Publikováno v:
Frontiers in Oncology, Vol 9 (2019)
Chronic myelogenous leukemia (CML) is a malignancy of the myeloid cell lineage characterized by a recurrent chromosomal abnormality: the Philadelphia chromosome, which results from the reciprocal translocation of the chromosomes 9 and 22. The Philade
Externí odkaz:
https://doaj.org/article/c0af551b5ce447108a0c86d7ff1bf65e
Autor:
Radu Precup, Jorge Rodríguez-López
Publikováno v:
Nonlinear Analysis, Vol 24, Iss 3 (2019)
This paper concerns the existence, localization and multiplicity of positive solutions for a φ-Laplacian problem with a perturbed term that may have discontinuities in the state variable. First, the initial discontinuous differential equation is rep
Externí odkaz:
https://doaj.org/article/8f7283d6d58247a9b6a8787808d4f0c8
Publikováno v:
Electronic Journal of Differential Equations, Vol 2016, Iss 254,, Pp 1-18 (2016)
We study the existence, localization and multiplicity of positive solutions for a nonlinear fourth-order two-point boundary value problem. The approach is based on critical point theorems in conical shells, Krasnoselskii's compression-expansion th
Externí odkaz:
https://doaj.org/article/5c0c727e638e48f6a2079c7d91f15bbf