Перегляд за темою "Математика"

Результати 21-40 з 718

H-розв’язнiсть задачi оптимального керування для виродженої елiптичної варiацiйної нерiвностi

Задоянчук, Н.В. (Доповіді НАН України, 2015)

Розглянуто задачу оптимального керування для виродженої елiптичної варiацiйної нерiвностi з ваговою функцiєю потенцiального типу, що входить до диференцiального оператора. Доведено розв’язнiсть задачi оптимального керування ...
Invariant solutions of a system of Euler equations that satisfy the Rankine—Hugoniot conditions

Yuryk, I.I. (Доповіді НАН України, 2018)

We consider equations of hydrodynamics with certain additional constraints. Group-theoretical methods are applied to find invariant solutions of a system of Euler equations that satisfy the Rankine–Hugoniot conditions.
Investigations of the properties of solutions of impulsive differential systems in the linear approximation

Mitropolsky, Yu.A.; Borysenko, S.D.; Toscano, S. (2008)

Проведено якiсний аналiз властивостей розв’язкiв нелiнiйних iмпульсних систем диференцiальних рiвнянь iз збуреннями на деяких гiперповерхнях {ti(x)}. Отримано новi умови обмеженостi, практичної стiйкостi за Четаєвим ...
Iснування глобальних атракторiв для iмпульсних динамiчних систем

Капустян, О.В.; Перестюк, М.О. (Доповіді НАН України, 2015)

Дослiджується iснування глобальних атракторiв для iмпульсних динамiчних систем, що мають траєкторiї з нескiнченною кiлькiстю iмпульсних збурень. Для параболiчного нелiнiйно збуреного рiвняння з iмпульсним впливом доведено ...
Leibniz algebras of dimension 3 over finite fields

Yashchuk, V.S. (Доповіді НАН України, 2018)

The first thing in the study of all types of algebras is the description of algebras having small dimensions. Unlike the simpler cases of 1- and 2-dimensional Leibniz algebras, the structure of 3-dimensional Leibniz ...
Linear groups saturated by subgroups of finite central dimension

Semko, N.N.; Skaskiv, L.V.; Yarovaya, O.A. (Доповіді НАН України, 2019)

Let F be a field, A be a vector space over F, and G be a subgroup of GL(F, A). We say that G has a dense family of subgroups having finite central dimension, if, for every pair of subgroups H, K of G such that H ≤ K and ...
Liouville comparison principle for solutions to semilinear parabolic second-order partial differential inequalities in the whole space

Kurta, V.V. (Доповіді НАН України, 2014)
Logarithmic capacity and Riemann and Hilbert problems for generalized analytic functions

Gutlyanskiĭ, V.Ya.; Nesmelova, O.V.; Ryazanov, V.I. (Доповіді НАН України, 2020)

The study of the Dirichlet problem with arbitrary measurable boundary data for harmonic functions in the unit disk is due to the famous Luzin dissertation. Later on, the known monograph of Vekua was devoted to ...
Mappings with finite length distortion and Riemann surfaces

Ryazanov, V.I.; Volkov, S.V. (Доповіді НАН України, 2020)

We prove a series of criteria in terms of dilatations for the continuous and homeomorphic extension of the map pings with finite length distortion between domains on Riemann surfaces to the boundary. The criterion for the ...
Multi-interval dissipative Sturm—Liouville boundary-value problems with distributional coefficients

Goriunov, A.S. (Доповіді НАН України, 2020)

The paper investigates spectral properties of multi-interval Sturm–Liouville operators with distributional coefficients. Constructive descriptions of all self-adjoint and maximal dissipative/accumulative extensions in ...
Multiinterval Sturm–Liouville boundary-value problems with distributional potentials

Goriunov, A.S. (Доповіді НАН України, 2014)

We study the multi-interval boundary-value Sturm–Liouville problems with distributional potentials. For the corresponding symmetric operators boundary triplets are found and the constructive descriptions of all self-adjoint, ...
Necessary condition for the existence of a simple closed geodesic on a regular tetrahedron in the spherical space

Sukhorebska, D.D. (Доповіді НАН України, 2020)

In the spherical space the curvature of the tetrahedron’s faces equals 1, and the curvature of the whole tetrahedron is concentrated into its vertices and faces. The intrinsic geometry of this tetrahedron depends on the ...
On analogs of some classical group theoretical results in Poisson algebras

Kurdachenko, L.A.; Pypka, A.A.; Subbotin, I.Ya. (Доповіді НАН України, 2021)

We investigate the Poisson algebras, in which the n-th hypercenter (center) has a finite codimension. It was established that, in this case, the Poisson algebra P includes a finite-dimensional ideal K such that P/K is ...
On analogs of some group-theoretic concepts and results for Leibniz algebras

Kurdachenko, L.A.; Subbotin, I.Ya.; Semko, N.N. (Доповіді НАН України, 2018)

An algebra L over a field F is said to be a Leibniz algebra (more precisely a left Leibniz algebra) if it satisfies the Leibniz identity: [[a, b], c] = [a, [b, c]] – [b, [a, c]] for all a, b, c ∈ L. Leibniz algebras are ...
On a new approach to the study of plane boundary-value problems

Gutlyanskiĭ, V.Ya.; Ryazanov, V.I.; Yefimushkin, A.S. (Доповіді НАН України, 2017)

We give a short description of our recent results obtained by a new approach to the boundary-value problems, such as the Dirichlet, Hilbert, Neumann, Poincaré and Riemann problems, for the Beltrami equations and for ...
On blow-up solutions and dead zones in semilinear equations

Gutlyanskii, V.Ya.; Nesmelova, O.V.; Ryazanov, V.I. (Доповіді НАН України, 2018)

We study semilinear elliptic equations of the form div(A(z)∇u) = f(u) in Ω⊂ C, where A(z) stands for a symmetric 2×2 matrix function with measurable entries, det A =1, and such that 1/ K |ξ|² ≤ 〈A(z)ξ,ξ〉 ≤ K |ξ|², ξ ∈ R², ...
On boundary-value problems for generalized analytic and harmonic functions

Gutlyanskiĭ, V.Ya.; Nesmelova, O.V.; Ryazanov, V.I.; Yefimushkin, A.S. (Доповіді НАН України, 2020)

The present paper is a natural continuation of our last articles on the Riemann, Hilbert, Dirichlet, Poincaré, and, in particular, Neumann boundary-value problems for quasiconformal, analytic, harmonic functions and the ...
On boundary value problems in domains without (A)-condition

Gutlyanskii, V.Ya.; Ryazanov, V.I.; Yakubov, E.; Yefimushkin, A.S. (Доповіді НАН України, 2019)

We study the Hilbert boundaryvalue problem for the Beltrami equations in the Jordan domains satisfying the quasihyperbolic boundary condition by Gehring—Martio, generally speaking, without the standard (A)condition by ...
On exact solutions of the nonlinear heat equation

Barannyk, A.F.; Barannyk, T.A.; Yuryk, I.I. (Доповіді НАН України, 2019)

A method for construction of exact solutions to the nonlinear heat equation ut = (F (u)ux)x + G (u)ux + H (u), which is based on the ansatz p(x) = ω₁(t) φ(u) + ω₂(t), is proposed. The function p(x) is a solution of the ...
On Fredholm parameter-dependent boundary-value problem in Sobolev spaces

Atlasiuk, O.M.; Mikhailets, V.A. (Доповіді НАН України, 2020)

We consider the most general class of linear inhomogeneous boundary-value problems for systems of r-th order ordinary differential equations whose solutions and right-hand sides belong to appropriate Sobolev spaces. ...

Результати 21-40 з 718

Пошук

Розширений пошук

Перегляд

Вся бібліотека

Перегляд за темою "Математика"

Репозиторій DSpace/Manakin

Перегляд за темою "Математика"

Пошук

Перегляд

Вся бібліотека

Мій обліковий запис