Eurasian Journal of Mathematical and Computer Applications

For the wave equation with inhomogeneity σ(x)um t + q(x)up a forward and an one-dimensional inverse problems are studied. Here m &gt; 1 and p &gt; 1 are real numbers. The forward problem is considered in the domain x &gt; 0,t &gt; 0 with zero initial data and Dirichlet boundary condition at x = 0. An unique solvability theorem of this problem is proved. The inverse problem is devoted to determining the coefficients σ(x) and q(x). As an additional information for recovering this coefficients, two forward problems with different Dirichlet data are considered and traces of the derivative of their solutions with respect to x are given at x =0 on a finite interval. For the inverse problem a local existence and uniqueness theorem is established.

V Romanov

T Bugueva

An one-dimensional inverse problem for the wave equation

一维波动方程的逆问题

Consider a model of information propagation through a network based on time- dependent directed graphs. Let us consider a pulse that starts at any node and an index—a real function acting on the nodes of the network—that represents the state of a node with respect to the transit of this signal. We present a flow-type equation to be satisfied by these indices, which allows us to unify the method for writing the mathematical formulas describing their evolution, and also to define new indices for global evaluation of the information circulation process. We focus our attention on the dissemination of information through Twitter, showing that PageRank is a basic example of index satisfying the flow equation, and also that we can use the flow equation to generate new meaningful indices in a constructive way.

None Falciani

None S ́anchez P ́erez

A FLOW EQUATION FOR DYNAMIC GRAPH CONTROL: APPLICATIONS TO SOCIAL NETWORK ANALYSIS

动态图控制流方程：应用于社交网络分析

The article describes an algorithm for constructing unstructured triangulation mesh using the advanced front method. The method of correcting errors of intersection of edges, which usually occurs while constructing triangular mesh, is presented. The errors and their correction are demonstrated in the form of diagrams. Also, in order to compare the parameters at certain nodes before and after changing the boundary of the elastic domain, the article considers the possibility of constructing an additional mesh when a certain part of the boundary of the domain changes in the direction of increase, while the original mesh in the remaining parts of the domain is not changed. The article contains the results of triangulation of certain examples in the form of diagrams. Taking into account that the triangulation code by the method of advanced front was not found in the open access, the approximate code of triangulation including the above methods was written in the Python programming language and posted on the Internet (the link is provided). The article includes a general description of the code. The matplotlib package was used to visualize the results.

None Temirbekov

None Kanagatov

None Tamabay

TRIANGULATION BY THE ADVANCED FRONT METHOD WITH SOME ADDITIONS

高级前方法与一些补充的三角剖分

In this article we consider a mathematical model of interpretation of a geoelectric section based on georadar data. One of the reasons preventing the spread of GPR technologies is the complexity of data interpretation, which requires the involvement of highly qualified specialists. In this regard, the study of the mathematical model and comparison with real georadar data expands the possibilities of interpretation of the georadar. To test the algorithm for solving the inverse problem of determining the electrical conductivity of layered media, data from exploration wells of the Karaganda coal basin field were used. We assume that the medium is horizontally layered and the electromagnetic pa- rameters of the medium depend only the depth. The problem of determining the conductivity is reduced to the problem of minimizing the cost functional by the gra- dient method. The gradient of the functional is calculated through the solution of the adjoint problem, the results of numerical calculations are given.

Maxim Shishlenin

Aliya Shakhatova

Tolkyn Mirgalikyzy

RECOVERING OF THE RESERVOIR CONDUCTIVITY BY MEASUREMENTS ON THE SURFACE USING GPR DATA

利用GPR数据通过地表测量恢复储层导水率

The aim of this work is to develop a new Reservoir People (RP) transmission mathematical model, to simulate the potential transmission of COVID-19 virus and Delta variant in the Moroccan population during the vaccination period. The originality of this work resides in the fact that the different parameters that appear in the model problem, depend on the period of vaccination. The existence and uniqueness of non-negative normalized solutions are proved. A cost function to minimize with respect to the parameters is defined. To this aim, a novel hybrid algorithm, called Neural Network with Sine-Cosine algorithm (NNSCA) is proposed. The obtained numerical simulation confirms that our model is robust and can efficiently predict the evolution of the virus in Morocco during the vaccination period.

Fatima Aqel

Alaa Hamza

Alaa Nour Eddine

MATHEMATICAL MODEL OF COVID-19 TRANSMISSIBILITY DURING THE VACCINATION PERIOD

COVID-19疫苗接种期间传播性的数学模型

Banana Bunch Top Disease (BBTD) is a severe viral infection that poses a significant threat to banana production in tropical regions. Caused by the Banana Bunchy Top Virus (BBTV) and transmitted primarily by the banana aphid (Pentalonia nigronervosa), BBTD results in stunted growth and poor fruit production, leading to substantial economic losses. This paper presents a mathematical model to analyze the transmission dynamics of BBTD in banana plants and evaluate various control strategies using the Next Generation Matrix approach to compute the basic reproduction number R0. The study reveals that effective control of aphid populations, timely removal of infected plants, and the use of virus-free planting material significantly reduce the spread of BBTV and improve plant health. Increasing the removal rate γ and managing the transmission rate β are crucial strategies for controlling the disease, while elevated aphid infection rates λ and progression rates σ exacerbate its spread. Numerical simulations highlight the effectiveness of targeted interventions, including the application of pesticides and the introduction of resistant banana varieties. The study recommends that, in addition to current control measures, more focus should be placed on comprehensive monitoring programs, early detection of symptoms, and community education on BBTD management strategies. Enhanced efforts in these areas are crucial to reducing the incidence of BBTD and improving the resilience of banana crops.

F Mrope

N Jeeva

Modeling the transmission dynamics of banana bunch top disease in banana plants

香蕉束顶病在香蕉植株中传播动力学的建模

Image denoising presents a significant challenge in computer vision, aiming to eliminate unwanted noise from images and restore their original quality. Cauchy noise, characterized by its heavy-tailed distribution, poses a unique hurdle among various types of noise. While several denoising models have been proposed, Total Variation (TV)-based methods, such as the Remove Cauchy Noise model, are widely used for their effectiveness. However, these approaches often suffer from issues such as oversmoothing, staircase artifacts, and the introduction of false details. To address these limitations, recent research has explored the combination of high-order TV with Overlapping Group Sparsity (OGS), showing promising results in noise removal. Inspired by this, our article introduces a novel Cauchy denoising model. Our approach leverages OGS and directional higher-order TV to effectively remove Cauchy noise while preserving image details and minimizing aliasing and smoothing artifacts. The Chambolle-Pock algorithm efficiently solves the underlying optimization problem. Through qualitative and quantitative evaluations, including visualization and parameter measurements, we demonstrate the competitiveness of our model compared to existing methods.

C Pham

T Tran

T Truong

N Nguyen

T Pham

Cauchy noise removal using high-order total variation and overlapping group sparsity

利用高阶全变差和重叠组稀疏性去除柯西噪声

The present work deals with the experimental and numerical study of steadystate conjugate heat transfer during impingement of turbulent air jet over a heated stainless steel. The plate is heated using copper heater located at the middle. The temperature field is measured using an infrared camera and compared with the numerical simulations. Numerical simulations are performed using three-dimensional finite volume based formulation. The turbulence shear-stress transport (SST) is modeled using k−ω model based on the Reynolds averaged Navier Stokes (RANS) equations. The numerical simulations are in good agreement with the experimental data with marginal discrepancy in the steel plate region due to the contact thermal resistance between steel and copper. It is observed that the local Nusselt number increased in the stagnation region with increasing velocity of the impinging turbulent flow and practically unaltered in the region of the steel plate.

A Mungalov

N Sibiryakov

D Kochkin

V Cheverda

P Somwanshi

O Kabov

Turbulent impinging air jet for cooling the heated surface

加热表面冷却的湍流冲击气流射流

A numerical study of the processes of heat and mass transfer in the furnace of a thermogravimetric analyzer was carried out, aimed at improving the accuracy of determining the kinetic characteristics of samples during their thermal transformations in different media. Validation of the model and prognostic estimates were carried out in relation to specially conducted thermogravimetric studies of the conversion of fossil and renewable carbon-containing raw materials in successive processes of decarbonization (combustion) and carbonation (mineralization of ash residue). The application of the study results allows to calculate the actual concentrations of the reagent over the sample uncontrolled by the device during pulsed switching of media and the actual temperatures of the sample during its thermochemical transformations.

G Maslennikov

G Nikitina

A Nikitin

P Osipov

A Ryzhkov

Physical and numerical simulation of heat and mass transfer in the furnace of a thermogravimetric analyzer

热重分析仪炉内传热传质过程的物理与数值模拟

短名
Journal Impact	0.43
国际分区	MATHEMATICS, INTERDISCIPLINARY APPLICATIONS(Q4)

ISSN	2306-6172, 2308-9822
h-index	12

涉及主题	计算机科学数学物理量子力学数学分析工程类哲学语言学几何学生物人工智能应用数学地质学材料科学
出版信息	出版商: L.N. Gumilyov Eurasian National University，出版周期: ，期刊类型: journal，开源期刊: 否
基本数据	创刊年份: 2013，原创研究文献占比: 100.00%，自引率:16.70%， Gold OA占比: 0.00%

Eurasian Journal of Mathematical and Computer Applications

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An one-dimensional inverse problem for the wave equation

A FLOW EQUATION FOR DYNAMIC GRAPH CONTROL: APPLICATIONS TO SOCIAL NETWORK ANALYSIS

TRIANGULATION BY THE ADVANCED FRONT METHOD WITH SOME ADDITIONS

RECOVERING OF THE RESERVOIR CONDUCTIVITY BY MEASUREMENTS ON THE SURFACE USING GPR DATA

MATHEMATICAL MODEL OF COVID-19 TRANSMISSIBILITY DURING THE VACCINATION PERIOD

An one-dimensional inverse problem for the wave equation

Modeling the transmission dynamics of banana bunch top disease in banana plants

Cauchy noise removal using high-order total variation and overlapping group sparsity

Turbulent impinging air jet for cooling the heated surface

Physical and numerical simulation of heat and mass transfer in the furnace of a thermogravimetric analyzer