## Seminars

** The weekly scientific seminar devoted to the modern problems of applied mathematics is held. on Tuesday, at 10 ^{00} o'clock. **

** Interested persons can take part.**

**20.04.2021 the Institute will hold a webinar via video conference.**

**Lector: professor **** Arazov Hasanbay**

**Theme: **Time in mathematical simulations of the theory of population of observed families of small bodies in non-linear dynamic systems

**Abstract: **Time continuously controls the variability of the observed natural resources; time teaches by numerous observable examples; time controls the movements of numerous objects at different speeds. Time discards unnecessary stresses in families of small bodies in dynamic systems. It plays the role of a cleaner from excess energies in nature. It leaves only really necessary tensions. Time always starts on time and stops in time. The beginning of time coincides with the beginning of the birth of the Universe. The end of time coincides with the end of the Universe's lifetime. The observed centuries-old systems of birth and evolution of compounds of elements of both living and non-living forms of matter over a millennium, in the dynamic systems of the family of populations of small bodies are indicated as example

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**13.04.2021 the Institute will hold a webinar via video conference.**

**Lector: professor ****Gamzaev Kh.M.**

**Theme: Turbulent flow of fluid in the pipeline numerical modeling method**

**Abstract: In the report, the issues of numerical investigation of turbulent flow of bircins fluid in pipelines are considered. Using the theory of semi-empirical turbulence of prandatlin, a mathematical model of the flow is proposed, on the basis of which the question of determining the hydraulic characteristics of the pipeline is put. The numerical solution of this problem, which belongs to the class of inverse problems, is proposed. The report interprets the results of the computational experiment conducted on the model issue.**

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**06.04.2021 the Institute will hold a webinar via video conference.**

**Lector: professor Mahammad Camalbayov**

**Theme: NEW CONCEPT FOR IMITATION MODELING OF THE DYNAMIC SYSTEMS: Theory and Application**

**Abstract: ***A new simulation concept of dynamic systems is being developed. The main idea, terms of the concept and principles of creating a model of a complex physical process are presented, which imply the division of the process under consideration into separate objects connected with each other by a cause-and-effect relationship. The proposed concept is applied to modeling the process of developing a volatile oil reservoir operated by a well equipped with a submersible sucker rod pump in a pump-well-reservoir system. Algorithms have been developed to predict the main indicators of the process, taking into account the PVT properties of fluids and phase transformations of the hydrocarbon system during filtration in the reservoir. The presence of the annular space in the well and the crossflow between the annular space and the lift pipe are taken into account. A number of computer studies were carried out on the basis of the developed model.*

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**16.03.2021 the Institute will hold a webinar via video conference.**

**Lector: Dr. Maryam Molayi**

**Theme: **The new class of multistep multiderivative hybrid methods for the numerical solution of chemical stiff systems of first order IVPs.

**Abstract:*** **In this paper, we present a general form of Nth derivative multistep methods. In these hybrid multistep multiderivative methods, additional stage points (or off-step points) have been used in the first derivative of the solution to improve the absolute stability regions. The accuracy and stability properties of these methods are investigated. We apply the new methods for the numerical integration of some famous stiff chemical problems such as Belousov–Zhabotinskii reaction, the Chapman atmosphere, chemical Akzo-Nobel problem, ROBER problem (suggested by Robertson) and some others which are widely used in numerical studies.** *

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**02.03.2021 the Institute will hold a webinar via video conference.**

**Lector:*** Dr. Reza Şokri *

**Theme: *** Efficient explicit nonstandard finite difference scheme with positivity-preserving propert.*

**Abstract:*** Solving problems in various fields of science and engineering, such as physical and biological systems, leads to solving parabolic equations of the advectiondiffusion reaction (ADR) type. In these problems, usually the concentration of chemical compounds or the size of the population are our unknowns, which are positive in nature. In general, the use of common methods, such as the classical finite difference method, may produce numerical drawbacks such as spurious oscillations and negative values in the solutions due to truncation errors. By using the nonstandard finite difference (NSFD) method, a better finite difference model is constructed. The proposed NSFD scheme ensures that the solutions are positive and there are no spurious oscillations in the solutions.*

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**23.02.2021 the Institute will hold a webinar via video conference.**

**Lector:*** professoe Yagub Sharifov*

**Theme: ****Existence and uniqueness of the solution of nonlinear impulsive differential equations of the first order of multipoint boundary conditional**

**Abstract: ***The existence and uniqueness of the solution of the first-order solution of nonlinear impulsive differential equations with multiple point boundary conditions is investigated. The given initial boundary value problem is reduced to an integral equation equivalent to it. The existence and uniqueness of the solution is based on Banach's principle of compressed reflection. The existence of the solution is based on Krasnoselsky's and Schaufer's theorems on fixed points.*

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**16.02.2021 the Institute will hold a webinar via video conference.**

**Lector:**** ****Ahmet Ocak Akdemir, Professor of Mathematics, Ataturk University, will deliver a speech entitled "New integral inequalities for Atangana-Baleanu fractional integral operators".**

** Theme: **NEW INTEGRAL INEQUALITIES FOR ATANGANA-BALEANU FRACTIONAL INTEGRAL OPERATORS

**Abstract. **Integral identities created in inequality theory studies help to prove many inequalities. Recently, different fractional integral and derivative operators have been used to achieve these identities. In this article, with the help of Atangana-Baleanu integral operators, an integral identity was first obtained and various integral inequalities for convex functions have been proved using this identity.

*NEW INTEGRAL INEQUALITIES FOR ATANGANA-BALEANU FRACTIONAL INTEGRAL OPERATORS *

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**08.05.2018**

**Theme: ****An approach to numerical solution to inverse-coefficient problems for a parabolic equation**

**Lector: ****Leading scientist of The Institute of Control Systems of ANAS, Anar Rahimov**

The inverse problems are considered for a parabolic equation with an unknown source (space or time dependent) on the right-hand side. In particular, these classes of problems arise in the study of boundary value problems with nonlocal (integral) conditions. A numerical method is proposed to solve the problems, which is based on the use of the method of lines. The initial problems are reduced to a system of ordinary differential equations with unknown parameters. To determine unknown parameters non-iterative method is proposed. We present the results of numerical experiments on test problems.

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**24.04.2018**

**Theme: Applying the theory of fuzzy time series in forecasting of the rate of USD / AZN**

**Lector: Shikhlinskaya R.Y.**

*In the presented article, forecasting of the currency quotation USD / AZN is considered using fuzzy time series (FTS). It provides a step by step description of the technique, which represents the construction of fuzzy term sets for the linguistic variable "exchange rate”, using input data as numerical values and calculating relationship to predict future states. In particular, the fact that Azerbaijani manat is a commodity currency is taken into account and the dollar exchange rate for manat depends on the cost of oil and is regulated by the state. Forecasting FTS is carried out in the direction of the application of new methods, called Times-Series Data Mining.*

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**06.02.2018**

**Theme: Analytical construction of regulators for systems with fractional derivatives**

**Lector: Fikret Aliev**

*The problem of analytic construction of regulators (AKP) is considered when the motion of an object is described by a system of linear differential equations of fractional derivatives with constant coefficients. Expressions are given for an analogous (ordinary derivative) Euler-Lagrange equation, where the fundamental matrix-solution is constructed using the Mittag-Leffler function. The above scheme is such that the order of the derivative. An example illustrating the proposed method is given.*

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**13.02.2018**

**Theme: Identification problem for defining the coefficient of hydraulic resistance on different areas of pump-compressor pipes in gaslift process **

**Lector: I. Maharramov**

In the work the coefficient of hydraulic resistance on different areas of pumpcompressor pipes in the oil production in gas lift wells is considered. By means of the least-squares method, the coefficient of hydraulic resistance is obtained using statistical data. An example is given that shows the adequacy of the mathematical model.