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Full-Text Articles in Physical Sciences and Mathematics

A Problem Of Solute Transport In A Cylindrical Porous Media With A Fractal Structure Taking Into Account Adsorption Phenomena, B. X. Xujayorov, J. M. Maxmudov, A. I. Usmanov, B. O. Saidov Jan 2020

A Problem Of Solute Transport In A Cylindrical Porous Media With A Fractal Structure Taking Into Account Adsorption Phenomena, B. X. Xujayorov, J. M. Maxmudov, A. I. Usmanov, B. O. Saidov

Scientific Journal of Samarkand University

The process of anomalous solute transport in a coaxial cylindrical porous media is modelled by differential equations with a fractional derivative. The problem of solute transport in a two-zone cylindrical media consisting of macro- and micropores taking into account adsorption effectshas been numericallyposed and solved. The concentration profiles of suspended particles and the adsorbed solute in the macropore and micropore, the surface of the local concentration in the micropore are determined. The influence of adsorption phenomena and the order of the derivative with respect to the coordinate, i.e. fractal dimension of the media, on the characteristics of the solute transport …


On A Two-Speed Mathematical Model Of Two-Fluid Medium With One Pressure, X. X. Imomnazarov, S. B. Kuyliyev Jan 2020

On A Two-Speed Mathematical Model Of Two-Fluid Medium With One Pressure, X. X. Imomnazarov, S. B. Kuyliyev

Scientific Journal of Samarkand University

An overdetermined stationary system of second-order differential equations is obtained. For the two-dimensional system, a variational statement of the problem is established. It is shown that the variational problem for the system of equations of two-speed hydrodynamics is well-posed in the corresponding Sobolev space


The Cauchy Problem For The System Of The Elasticity, I. E. Niyozov, O. Karshiboyev Jan 2020

The Cauchy Problem For The System Of The Elasticity, I. E. Niyozov, O. Karshiboyev

Scientific Journal of Samarkand University

In this paper we consider the problem of analytical continuation of solutions to the system of the elasticity in a bounded domain from their values and values of their strains on a part of the boundary of this domain, i.e., we study the Cauchy problem


On Estimates For The Damped Oscillatory Integrals, I. A. Ikromov, Sh. A. Muranov Jan 2020

On Estimates For The Damped Oscillatory Integrals, I. A. Ikromov, Sh. A. Muranov

Scientific Journal of Samarkand University

In this paper we consider estimates of the Fourier transform measures, concentrated on analytic hypersurfaces containing the of damping factor. The paper presents the solution of the problem S.D.Soggi and I.M. Stein about the optimal decay of the transformation Fourier measures with a damping factor for any analytic surfaces in three-dimensional Euclidean space.


Of The Cauchy Problem For Thelaplace Equations On A Plane, D. S. Shodiyev Jan 2020

Of The Cauchy Problem For Thelaplace Equations On A Plane, D. S. Shodiyev

Scientific Journal of Samarkand University

In this paper, a uniqueness theorem is proved, and an estimate of conditional stability is obtained, and an approximate solution is constructed by the method of quasi-derivation and Tikhonov regularization.


The Problem Of Integral Geometry In A Strip With Weight Function, A. X. Begmatov, A. S. Ismoilov Jan 2020

The Problem Of Integral Geometry In A Strip With Weight Function, A. X. Begmatov, A. S. Ismoilov

Scientific Journal of Samarkand University

In this work we consider the problem of reconstructing a function from a family of parabolas in the upper half-plane with a weight function having a singularity. The uniqueness of theorem for the solution of equation is proved and the inversion formula is derived. It is shown that the solution of the problem posed is weakly ill-posed, that is, stability estimates are obtained in spaces of finite smoothness.


Uniqueness And Stability Problem Of Integral Geometry With Indignation, Akram Begmatov, Zarifjon Ochilov, Abduroziq Xusanov Jan 2020

Uniqueness And Stability Problem Of Integral Geometry With Indignation, Akram Begmatov, Zarifjon Ochilov, Abduroziq Xusanov

Scientific Journal of Samarkand University

Рассматривается новый класс задач интегральной геометрии типа Вольтерра с функцией специального веса. Доказаны теоремы единственности и существования решения, получены оценки устойчивости и формула обращения в пространствах Соболева, что свидетельствует о слабой некорректности решения задачи интегральной геометрии. Постановка задачи интегральной геометрии с возмущением на семейство парабол в полосе считается. Теорема единственности ее решения доказана в классе дважды непрерывно дифференцируемых функций с компактным носителем, а оценки устойчивости получены в пространствах конечной гладкости.


Effectiveness Analysis Of Generalization Of Algorithms For Increasing Information Reliability Based On Usage Of Information Redundancy Of Electronic Documents, I.I. Jumanov, Kh.B. Karshiyev Jun 2019

Effectiveness Analysis Of Generalization Of Algorithms For Increasing Information Reliability Based On Usage Of Information Redundancy Of Electronic Documents, I.I. Jumanov, Kh.B. Karshiyev

Scientific Journal of Samarkand University

Approaches are proposed to use natural redundancy to increase the reliability of information in the form of logical, semantic, technological, statistical relationships, properties and relations of elements and key concepts of the document. The developed methods and algorithms are based on the mechanisms of refinement, adjustment and control of the values of elements, features, attributes, concepts of the document. Implemented a modified associative semantic network of image search - a document by segmentation in the form of its fragments and components.


Continuation Of Polyanalytic Functions, T. Ishankulov, G. Norqulova Jun 2019

Continuation Of Polyanalytic Functions, T. Ishankulov, G. Norqulova

Scientific Journal of Samarkand University

We consider the problem of continuation the � − analytic function in to a domain by values of its sequential derivatives up to the (� − 1) -th order on a part of the boundary. The problem of inversion of a Cauchy type integral to a Cauchy integral for such functions is also considered.


The Problem Of Integral Geometry For A Family Curves With Specials, A.Kh. Begmatov, Z.X. Ochilov, A.Z. Khusanov Feb 2019

The Problem Of Integral Geometry For A Family Curves With Specials, A.Kh. Begmatov, Z.X. Ochilov, A.Z. Khusanov

Scientific Journal of Samarkand University

We study new problem of reconstruction of a function in a strip from their given integrals with known weight function along polygonal lines. We obtained two simply inversion formulas for the solution to the problem. We prove uniqueness theorems for solutions and obtain stability estimates of a solution to the problem in Sobolev’s spaces and thus show their weak illposedness.


Estimation Of Oscillatory Integrals With Special Phase, G.A. Khasanov Feb 2019

Estimation Of Oscillatory Integrals With Special Phase, G.A. Khasanov

Scientific Journal of Samarkand University

In this paper, we consider uniform estimates for oscillatory integrals with some phase functions depending on small parameters.


On The Cauchy Problem For The Laplace Equation, A.B. Khasanov, Z. Malikov, F.R. Tursunov Feb 2019

On The Cauchy Problem For The Laplace Equation, A.B. Khasanov, Z. Malikov, F.R. Tursunov

Scientific Journal of Samarkand University

The article studies the problem of continuation of the solution and the stability estimate of the Cauchy problem for the Laplace equation in a domain G by its known values on the smooth part S of the boundary G  . The considered problem belongs to the problems of mathematical physics, in which there is no continuous dependence of solutions on the initial data. It is assumed that the solution to the problem exists and is continuously differentiable in a closed domain with exac tly given Cauchy data. For this case, an explicit formula for the continuation of the solution …


On Negative Eigenvalues Of The Discrete Schrödinger Operator With Non-Local Potential, Sh.S. Lakaev, Z.E. Muminov Oct 2018

On Negative Eigenvalues Of The Discrete Schrödinger Operator With Non-Local Potential, Sh.S. Lakaev, Z.E. Muminov

Scientific Journal of Samarkand University

On the d- dimensional lattice 2 , 1 ,  d d Z the discrete Schrödinger operator  H with non- local potential constructed via the Dirac delta function and shift operator is considered. The existence of negative eigenvalues on the parameters of the operator is explicity derived.


The Problem Of Restoring A Function In A Strip Along Curves With Singularities, А.Kh. Begmatov, A.S. Ismoilov Oct 2018

The Problem Of Restoring A Function In A Strip Along Curves With Singularities, А.Kh. Begmatov, A.S. Ismoilov

Scientific Journal of Samarkand University

In this work we consider the problem of re constructing a function from a family of parabolas in the upper half-plane with a weight function having a singularity. The uniqueness of theorem for the solution of equation is proved and the inversion formula is derived. It is shown that the solution of the problem posed is weakly ill -posed, that is, stability estimates are obtained in spaces of finite smoothness.


The Cauchy Problem For The System Of The Moment Elasticity, I.E. Niyozov, Т. Begmatov Oct 2018

The Cauchy Problem For The System Of The Moment Elasticity, I.E. Niyozov, Т. Begmatov

Scientific Journal of Samarkand University

In this paper we consider the problem of analytical continuation of solutions to the system of the moment elasticity in a bounded domain from their values and values of their strains on a part of the boundary of this domain, i.e., we study the Cauchy proble m.


The Extension Of The Generalized Analytic Functions, Т. Ishonqulov, D. Fozilov Jun 2018

The Extension Of The Generalized Analytic Functions, Т. Ishonqulov, D. Fozilov

Scientific Journal of Samarkand University

In this paper we consider the problem of extending a generalized analytic function to a unit disk from its known values on the arc of the boundary circle. A criterion for the solvability of this problem is established.


The Integral Formula For First-Order Elliptic Systems With Constant Coefficients In An Unbounded Domain, F.R. Tursunov Feb 2018

The Integral Formula For First-Order Elliptic Systems With Constant Coefficients In An Unbounded Domain, F.R. Tursunov

Scientific Journal of Samarkand University

In this note we present a formula for the solutions of systems of first -order differential equations of elliptic type of a special class in an unbounded domain.


On The Some Generalizations And Improvements Of The Best Polynomial Approximations Of Functions Of Many Real Variables, A. Khatamov Feb 2018

On The Some Generalizations And Improvements Of The Best Polynomial Approximations Of Functions Of Many Real Variables, A. Khatamov

Scientific Journal of Samarkand University

The paper is devoted to some generalizations and improvements of results obtained in the paper [1] of the best joint polynomial approximations in uniform and integral metrics on a given bounded closed convex domain of the functions of many real variables (FMRV) from the seminormalized Sobolev space with last derivative of integrable on nonempty intersections of each straight line with this domain.