Математика список научных статей
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LATTICE UNIVERSALITY OF LOCALLY FINITE p -GROUPS
For an arbitrary prime p , we prove that every algebraic lattice is isomorphic to a complete sublattice in the subgroup lattice of a suitable locally finite p -group. In particular, every lattice is embeddable in the subgroup lattice of a locally finite p -group.
2023 / Vladimir B. RepnitskiǐScopusВАК
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FIXED RATIO POLYNOMIAL TIME APPROXIMATION ALGORITHM FOR THE PRIZE-COLLECTING ASYMMETRIC TRAVELING SALESMAN PROBLEM
We develop the first fixed-ratio approximation algorithm for the well-known Prize-Collecting Asymmetric Traveling Salesman Problem, which has numerous valuable applications in operations research. An instance of this problem is given by a complete nodeand edge-weighted digraph G . Each node of the...
2023 / Ksenia Rizhenko, Katherine Neznakhina, Michael KhachayScopusВАК -
HYERS–ULAM–RASSIAS STABILITY OF NONLINEAR DIFFERENTIAL EQUATIONS WITH A GENERALIZED ACTIONS ON THE RIGHT-HAND SIDE
The paper considers the Hyers–Ulam–Rassias stability for systems of nonlinear differential equations with a generalized action on the right-hand side, for example, containing impulses — delta functions. The fact that the derivatives in the equation are considered distributions required a correction ...
2023 / Alexander N. Sesekin, Anna D. KandrinaScopusВАК -
THE MINIMAL DOMINATING SETS IN A DIRECTED GRAPH AND THE KEY INDICATORS SET OF SOCIO–ECONOMIC SYSTEM
The paper deals with a digraph with non-negative vertex weights. A subset W of the set of vertices is called dominating if any vertex that not belongs to it is reachable from the set W within precisely one step. A dominating set is called minimal if it ceases to be dominating when removing any...
2023 / Ruslan Yu. Simanchev, Inna V. Urazova, Vladimir V. VoroshilovScopusВАК -
ON ONE ZALCMAN PROBLEM FOR THE MEAN VALUE OPERATOR
Let D′(Rn) and E′(Rn) be the spaces of distributions and compactly supported distributions on Rn , n≥2 respectively, let E′♮(Rn) be the space of all radial (invariant under rotations of the space mathbbRn ) distributions in E′(Rn) , let T˜ be the spherical transform (Fourier–Bessel transform) of a...
2023 / Natalia P. Volchkova, Vitaliy V. VolchkovScopusВАК -
APPROXIMATION OF DIFFERENTIATION OPERATORS BY BOUNDED LINEAR OPERATORS IN LEBESGUE SPACES ON THE AXIS AND RELATED PROBLEMS IN THE SPACES OF (p, q)-MULTIPLIERS AND THEIR PREDUAL SPACES
We consider a variant En,k(N ; r, r; p, p) of the four-parameter Stechkin problem En,k(N ; r, s; p, q) on the best approximation of differentiation operators of order k on the class of n times differentiable functions (0 < k < n) in Lebesgue spaces on the real axis. We discuss the state of research ...
2023 / Vitalii V. ArestovScopusВАК -
COUNTABLE COMPACTNESS MODULO AN IDEAL OF NATURAL NUMBERS
In this article, we introduce the idea of I-compactness as a covering property through ideals of N and regardless of the I-convergent sequences of points. The frameworks of s-compactness, compactness and sequential compactness are compared to the structure of I-compact space. We began our research...
2023 / Prasenjit Bal, Debjani Rakshit, Susmita SarkarScopusВАК -
ON SEQUENCES OF ELEMENTARY TRANSFORMATIONS IN THE INTEGER PARTITIONS LATTICE
An integer partition, or simply, a partition is a nonincreasing sequence λ = (λ1, λ2, . . . ) of nonnegative integers that contains only a finite number of nonzero components. The length ℓ(λ) of a partition λ is the number of its nonzero components. For convenience, a partition λ will often be...
2023 / Vitaly A. Baransky, Tatiana A. SenchonokScopusВАК -
IK -SEQUENTIAL TOPOLOGY
In the literature, I-convergence (or convergence in I) was first introduced in [11]. Later related notions of I-sequential topological space and I∗-sequential topological space were introduced and studied. From the definitions it is clear that I∗-sequential topological space is larger(finer) than...
2023 / H. S. Behmanush, M KüçükaslanScopusВАК -
CANONICAL APPROXIMATIONS IN IMPULSE STABILIZATION FOR A SYSTEM WITH AFTEREFFECT
For optimal stabilization of an autonomous linear system of differential equations with aftereffect and impulse controls, the formulation of the problem in the functional state space is used. For a system with aftereffect, approximating systems of ordinary differential equations proposed by S.N....
2023 / Yuri F. DolgiiScopusВАК -
KERNEL DETERMINATION PROBLEM FOR ONE PARABOLIC EQUATION WITH MEMORY
This paper studies the inverse problem of determining a multidimensional kernel function of an integral term which depends on the time variable t and (n−1) -dimensional space variable x′=(x1,…,xn−1) in the n -dimensional diffusion equation with a time-variable coefficient at the Laplacian of a...
2023 / Durdimurod K. Durdiev, Javlon Z. NuriddinovScopusВАК -
COMPUTING THE REACHABLE SET BOUNDARY FOR AN ABSTRACT CONTROL SYSTEM: REVISITED
A control system can be treated as a mapping that maps a control to a trajectory (output) of the system. From this point of view, the reachable set, which consists of the ends of all trajectories at a given time, can be considered an image of the set of admissible controls into the state space...
2023 / Mikhail I. GusevScopusВАК -
A NEW CHARACTERIZATION OF SYMMETRIC DUNKL AND q -DUNKL-CLASSICAL ORTHOGONAL POLYNOMIALS
In this paper, we consider the following L -difference equation Φ(x)LPn+1(x)=(ξnx+ϑn)Pn+1(x)+λnPn(x),n≥0, where Φ is a monic polynomial (even), degΦ≤2 , ξn,ϑn,λn,n≥0 , are complex numbers and L is either the Dunkl operator Tμ or the the q -Dunkl operator T(θ,q) . We show that if L=Tμ , then the...
2023 / Yahia HabbachiScopusВАК -
CONTROL PROBLEM FOR A PARABOLIC SYSTEM WITH UNCERTAINTIES AND A NON-CONVEX GOAL
We consider the control problem for a parabolic system that describes the heating of a given number of rods. Control is carried out through heat sources that are located at the ends of the rods (only at one end or at both). The density functions of the internal heat sources and exact values of the...
2023 / Igor’ V. Izmest’ev, Viktor I. UkhobotovScopusВАК -
ON TWO-SIDED UNIDIRECTIONAL MEAN VALUE INEQUALITY IN A FRÉCHET SMOOTH SPACE
The paper is devoted to a new unidirectional mean value inequality for the Fréchet subdifferential of a continuous function. This mean value inequality finds an intermediate point and localizes its value both from above and from below; for this reason, the inequality is called two-sided. The...
2023 / Dmitry V. KhlopinScopusВАК -
CONVEXITY OF REACHABLE SETS OF QUASILINEAR SYSTEMS
This paper investigates convexity of reachable sets for quasilinear systems under integral quadratic constraints. Drawing inspiration from B.T. Polyak's work on small Hilbert ball image under nonlinear mappings, the study extends the analysis to scenarios where a small nonlinearity exists on the...
2023 / Ivan OsipovScopusВАК -
POLYNOMIALS LEAST DEVIATING FROM ZERO IN Lp(−1;1) , 0≤p≤∞ , WITH A CONSTRAINT ON THE LOCATION OF THEIR ROOTS
We study Chebyshev's problem on polynomials that deviate least from zero with respect to Lp -means on the interval [−1;1] with a constraint on the location of roots of polynomials. More precisely, we consider the problem on the set Pn(DR) of polynomials of degree n that have unit leading...
2023 / Alena E. RokinaScopusВАК -
SOME INEQUALITIES BETWEEN THE BEST SIMULTANEOUS APPROXIMATION AND MODULUS OF CONTINUITY IN THE WEIGHTED BERGMAN SPACE
Some inequalities between the best simultaneous approximation of functions and their intermediate derivatives, and the modulus of continuity in a weighted Bergman space are obtained. When the weight function is γ(ρ)=ρα, α>0 , some sharp inequalities between the best simultaneous approximation and...
2023 / Muqim S. SaidusainovScopusВАК -
A PRESENTATION FOR A SUBMONOID OF THE SYMMETRIC INVERSE MONOID
In the present paper, we study a submonoid of the symmetric inverse semigroup In . Specifically, we consider the monoid of all order-, fence-, and parity-preserving transformations of In . While the rank and a set of generators of minimal size for this monoid are already known, we will provide a...
2023 / Apatsara Sareeto, Jörg KoppitzScopusВАК -
GRACEFUL CHROMATIC NUMBER OF SOME CARTESIAN PRODUCT GRAPHS
A graph G(V,E) is a system consisting of a finite non empty set of vertices V(G) and a set of edges E(G) . A (proper) vertex colouring of G is a function f:V(G)→{1,2,…,k}, for some positive integer k such that f(u)≠f(v) for every edge uv∈E(G) . Moreover, if |f(u)−f(v)|≠|f(v)−f(w)| for every...
2023 / I Nengah Suparta, Mathiyazhagan Venkatachalam, I Gede Aris Gunadi, Putu Andi Cipta PratamaScopusВАК
