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2. Tensor Product Technique and Atomic Solution of Fractional Partial Differential Equations.
- Author
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Hammad, Ma'mon Abu, Alshanti, Waseem Ghazi, Alshanty, Ahmad, and Khalil, Roshdi
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TENSOR products , *BANACH spaces - Abstract
In this paper, we investigate the atomic solution of a special type of fractional partial differential equations. Tensor product in Banach spaces, some properties of atom operators, and some properties of conformable fractional derivatives are utilized in such process. JEL Classification: 34G10, 34A55 [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
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3. Symmetric Encryption Algorithms in a Polynomial Residue Number System.
- Author
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Yakymenko, I., Karpinski, M., Shevchuk, R., and Kasianchuk, M.
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NUMBER systems , *CRYPTOGRAPHY , *POLYNOMIALS , *NP-complete problems , *ALGORITHMS , *MULTIPLICATION - Abstract
In this paper, we develop the theoretical provisions of symmetric cryptographic algorithms based on the polynomial residue number system for the first time. The main feature of the proposed approach is that when reconstructing the polynomial based on the method of undetermined coefficients, multiplication is performed not on the found base numbers but on arbitrarily selected polynomials. The latter, together with pairwise coprime residues of the residue class system, serve as the keys of the cryptographic algorithm. Schemes and examples of the implementation of the developed polynomial symmetric encryption algorithm are presented. The analytical expressions of the cryptographic strength estimation are constructed, and their graphical dependence on the number of modules and polynomial powers is presented. Our studies show that the cryptanalysis of the proposed algorithm requires combinatorial complexity, which leads to an NP-complete problem. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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4. Mathematical Modeling of the Transmission Dynamics of Gumboro Disease.
- Author
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Musaili, J. S., Chepkwony, I., and Mutuku, W. N.
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INFECTIOUS disease transmission , *BASIC reproduction number , *MATHEMATICAL models , *ORDINARY differential equations , *POULTRY diseases , *POULTRY breeding - Abstract
Gumboro disease is a viral poultry disease that causes immune suppression on the infected birds leading to poor production, mortality, and exposure to secondary infections, hence a major threat in the poultry industry worldwide. A mathematical model of the transmission dynamics of Gumboro disease is developed in this paper having four compartments of chicken population and one compartment of Gumboro pathogen population. The basic reproduction number R og is derived, and the dynamical behaviors of both the disease-free equilibrium (DFE) and endemic equilibrium are analyzed using the ordinary differential equation theory. From the analysis, we found that the system exhibits an asymptotic stable DFE whenever R og < 1 and an asymptotic stable EE whenever R og > 1. The numerical simulation to verify the theoretical results was carried out using MATLAB ode45 solver, and the results were found to be consistent with the theoretical findings. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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5. Simultaneous Model Change Detection in Multivariate Linear Regression With Application to Indonesian Economic Growth Data.
- Author
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Somayasa, Wayan, Djafar, Muhammad Kabil, Muhtar, Norma, and Sutiari, Desak Ketut
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ECONOMIC statistics , *ECONOMIC expansion , *CENTRAL limit theorem , *MONTE Carlo method , *BROWNIAN motion - Abstract
In this paper, we study asymptotic model change detection in multivariate linear regression by using the Kolmogorov–Smirnov function of the partial sum process of recursive residuals. We approximate the rejection region and also the power function of the test by establishing a functional central limit theorem for the sequence of the partial sum processes of the recursive residuals of the observations. When the assumed model is true, the limit process is given by the standard multivariate Brownian motion which does not depend on the regression functions. However, when the assumed model is not true (some models change), the limit process is represented by a vector of deterministic trend plus the standard multivariate Brownian motion. The finite sample size rejection region and the power of the test are investigated by means of Monte Carlo simulation. The simulation study shows evidence that the proposed test is consistent in the sense that it attains the power larger than the size of the test when the hypothesis is not true. We also demonstrate the application of the proposed test method to Indonesian economic growth data in which we test the adequacy of three-variate low-order polynomial model. The test result shows that the growth of the Indonesian economy is neither simultaneously constant nor linear. The test has successfully detect the appearance of a change in the model which is mainly caused by the COVID-19 pandemic in 2020. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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6. The Significance of Stochastic CTMC Over Deterministic Model in Understanding the Dynamics of Lymphatic Filariasis With Asymptomatic Carriers.
- Author
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Stephano, Mussa A., Irunde, Jacob I., Mayengo, Maranya M., and Kuznetsov, Dmitry
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STOCHASTIC models , *MARKOV processes , *BRANCHING processes , *FILARIASIS - Abstract
Lymphatic filariasis is a leading cause of chronic and irreversible damage to human immunity. This paper presents deterministic and continuous-time Markov chain (CTMC) stochastic models regarding lymphatic filariasis dynamics. To account for randomness and uncertainties in dynamics, the CTMC model was formulated based on deterministic model possible events. A deterministic model's outputs suggest that disease extinction is feasible when the secondary threshold infection number is below one, while persistence becomes likely when the opposite holds true. Furthermore, the significant contribution of asymptomatic carriers was identified. Results indicate that persistence is more likely to occur when the infection results from asymptomatic, acutely infected, or infectious mosquitoes. Consequently, the CTMC stochastic model is essential in capturing variabilities, randomness, associated probabilities, and validity across different scales, whereas oversimplification and unpredictability of inherent may not be featured in a deterministic model. [ABSTRACT FROM AUTHOR]
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- 2024
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7. One-Step Family of Three Optimized Second-Derivative Hybrid Block Methods for Solving First-Order Stiff Problems.
- Author
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Yakubu, Saidu Daudu and Sibanda, Precious
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INITIAL value problems , *RELAXATION techniques - Abstract
This paper introduces a novel approach for solving first-order stiff initial value problems through the development of a one-step family of three optimized second-derivative hybrid block methods. The optimization process was integrated into the derivation of the methods to achieve maximal accuracy. Through a rigorous analysis, it was determined that the methods exhibit properties of consistency, zero-stability, convergence, and A-stability. The proposed methods were implemented using the waveform relaxation technique, and the computed results demonstrated the superiority of these schemes over certain existing methods investigated in the study. [ABSTRACT FROM AUTHOR]
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- 2024
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8. A New Efficient Hybrid Method Based on FEM and FDM for Solving Burgers' Equation with Forcing Term.
- Author
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Cakay, Aysenur Busra and Selim, Selmahan
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HAMBURGERS , *BURGERS' equation , *FINITE differences , *NONLINEAR differential equations , *ORDINARY differential equations , *PARABOLIC differential equations , *FINITE element method - Abstract
This paper presents a study on the numerical solutions of the Burgers' equation with forcing effects. The article proposes three hybrid methods that combine two-point, three-point, and four-point discretization in time with the Galerkin finite element method in space (TDFEM2, TDFEM3, and TDFEM4). These methods use backward finite difference in time and the finite element method in space to solve the Burgers' equation. The resulting system of the nonlinear ordinary differential equations is then solved using MATLAB computer codes at each time step. To check the efficiency and accuracy, a comparison between the three methods is carried out by considering the three Burgers' problems. The accuracy of the methods is expressed in terms of the error norms. The combined methods are advantageous for small viscosity and can produce highly accurate solutions in a shorter time compared to existing numerical schemes in the literature. In contrast to many existing numerical schemes in the literature developed to solve Burgers' equation, the methods can exhibit the correct physical behavior for very small values of viscosity. It has been demonstrated that the TDFEM2, TDFEM3, and TDFEM4 can be competitive numerical methods for addressing Burgers-type parabolic partial differential equations arising in various fields of science and engineering. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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9. Enhancing Malaria Control Strategy: Optimal Control and Cost-Effectiveness Analysis on the Impact of Vector Bias on the Efficacy of Mosquito Repellent and Hospitalization.
- Author
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Febiriana, Iffatricia Haura, Hassan, Abdullah Hasan, and Aldila, Dipo
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MALARIA , *BASIC reproduction number , *MALARIA prevention , *MOSQUITOES , *VECTOR analysis , *REPELLENTS , *HOSPITAL care - Abstract
This paper focuses on the impact of mosquito biting bias on the success of malaria intervention strategies. The initial model is developed considering the existence of symptomatic and asymptomatic humans, as well as vector bias. The model is then analyzed to demonstrate how the malaria-endemic equilibrium always exists and is globally asymptotically stable if the basic reproduction number is larger than one. On the other hand, malaria will always go extinct in the population if the basic reproduction number is less than one. For intervention analysis, the model is extended by considering mosquito repellent and hospitalization as control strategies. The control reproduction number is shown analytically. Using the Pontryagin maximum principle, we characterize our optimal control problem. Several scenarios are conducted to observe the dynamics of control variables under different circumstances. We found that the intervention of mosquito repellent and hospitalization together is the most cost-effective strategy to reduce the spread of malaria. Furthermore, we have shown that the more biased the vector attracted to infected individuals, the higher the cost needed to implement the control strategy. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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10. Analytical Approximate Solutions of Caputo Fractional KdV-Burgers Equations Using Laplace Residual Power Series Technique.
- Author
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Burqan, Aliaa, Khandaqji, Mona, Al-Zhour, Zeyad, El-Ajou, Ahmad, and Alrahamneh, Tasneem
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ANALYTICAL solutions , *CAPUTO fractional derivatives , *LAURENT series , *POWER series , *PARTIAL differential equations , *EQUATIONS , *NONLINEAR waves - Abstract
The KdV-Burgers equation is one of the most important partial differential equations, established by Korteweg and de Vries to describe the behavior of nonlinear waves and many physical phenomena. In this paper, we reformulate this problem in the sense of Caputo fractional derivative, whose physical meanings, in this case, are very evident by describing the whole time domain of physical processing. The main aim of this work is to present the analytical approximate series for the nonlinear Caputo fractional KdV-Burgers equation by applying the Laplace residual power series method. The main tools of this method are the Laplace transform, Laurent series, and residual function. Moreover, four attractive and satisfying applications are given and solved to elucidate the mechanism of our proposed method. The analytical approximate series solution via this sweet technique shows excellent agreement with the solution obtained from other methods in simple and understandable steps. Finally, graphical and numerical comparison results at different values of α are provided with residual and relative errors to illustrate the behaviors of the approximate results and the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
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11. Graph Crypto-Stego System for Securing Graph Data Using Association Schemes.
- Author
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Sabharwal, Anuradha, Yadav, Pooja, and Kumar, Kamal
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CRYPTOGRAPHY , *ABELIAN groups , *TELECOMMUNICATION , *CLOUD storage , *FINITE groups , *STATISTICS , *IMAGE encryption , *CLOUD computing - Abstract
Cryptography has recently become a critical area to research and advance in order to transmit information safely and securely among various entities, especially when the transmitted data is classified as crucial or important. This is due to the increase in the use of the Internet and other novel communication technology. Many businesses now outsource sensitive data to a third party because of the rise of cloud computing and storage. Currently, the key problem is to encrypt the data such that it may be stored on an unreliable server without sacrificing the ability to use it effectively. In this paper, we propose a graph encryption scheme by using cryptography and steganography. Data is encrypted using association schemes over finite abelian groups and then hiding the encrypted data behind randomly chosen cover image. We implemented and evaluated the efficiency of our constructions experimentally. We provide experimental results, statistical analysis, error analysis, and key analysis that demonstrates the appropriateness and efficiency of the proposed technique. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
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12. An Efficient New Technique for Solving Nonlinear Problems Involving the Conformable Fractional Derivatives.
- Author
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Ahmed, Shams A.
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PROBLEM solving , *DECOMPOSITION method , *NONLINEAR equations , *FRACTIONAL differential equations - Abstract
In this paper, an efficient new technique is used for solving nonlinear fractional problems that satisfy specific criteria. This technique is referred to as the double conformable fractional Laplace-Elzaki decomposition method (DCFLEDM). This approach combines the double Laplace-Elzaki transform method with the Adomian decomposition method. The fundamental concepts and findings of the recently suggested transformation are presented. For the purpose of assessing the accuracy of our approach, we provide three examples and introduce the series solutions of these equations using DCLEDM. The results show that the proposed strategy is a very effective, reliable, and efficient approach for addressing nonlinear fractional problems using the conformable derivative. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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13. Dynamics Analysis of a Delayed Crimean-Congo Hemorrhagic Fever Virus Model in Humans.
- Author
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Al-Jubouri, Karrar Qahtan and Naji, Raid Kamel
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HEMORRHAGIC fever , *BASIC reproduction number , *HOPF bifurcations , *INFECTIOUS disease transmission , *DISEASE vectors , *VIRUS diseases - Abstract
Given that the Crimean and Congo hemorrhagic fever is one of the deadly viral diseases that occur seasonally due to the activity of the carrier "tick," studying and developing a mathematical model simulating this illness are crucial. Due to the delay in the disease's incubation time in the sick individual, the paper involved the development of a mathematical model modeling the transmission of the disease from the carrier to humans and its spread among them. The major objective is to comprehend the dynamics of illness transmission so that it may be controlled, as well as how time delay affects this. The discussion of every one of the solution's qualitative attributes is included. According to the established basic reproduction number, the stability analysis of the endemic equilibrium point and the disease-free equilibrium point is examined for the presence or absence of delay. Hopf bifurcation's triggering circumstance is identified. Using the center manifold theorem and the normal form, the direction and stability of the bifurcating Hopf bifurcation are explored. The next step is sensitivity analysis, which explains the set of control settings that have an impact on how the system behaves. Finally, to further comprehend the model's dynamical behavior and validate the discovered analytical conclusions, numerical simulation has been used. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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14. Inexact Exponential Penalty Function with the Augmented Lagrangian for Multiobjective Optimization Algorithms.
- Author
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Tougma, Appolinaire and Some, Kounhinir
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OPTIMIZATION algorithms , *LAGRANGIAN functions , *EXPONENTIAL functions , *NUMERICAL solutions to differential equations , *PARETO optimum , *CONSTRAINED optimization - Abstract
This paper uses an augmented Lagrangian method based on an inexact exponential penalty function to solve constrained multiobjective optimization problems. Two algorithms have been proposed in this study. The first algorithm uses a projected gradient, while the second uses the steepest descent method. By these algorithms, we have been able to generate a set of nondominated points that approximate the Pareto optimal solutions of the initial problem. Some proofs of theoretical convergence are also proposed for two different criteria for the set of generated stationary Pareto points. In addition, we compared our method with the NSGA-II and augmented the Lagrangian cone method on some test problems from the literature. A numerical analysis of the obtained solutions indicates that our method is competitive with regard to the test problems used for the comparison. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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15. A Knee Point-Driven Many-Objective Evolutionary Algorithm with Adaptive Switching Mechanism.
- Author
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He, Maowei, Wang, Xu, Chen, Hanning, and Li, Xuguang
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ANGLES , *KNEE , *EVOLUTIONARY algorithms , *BENCHMARK problems (Computer science) , *MATE selection , *ALGORITHMS - Abstract
The Pareto dominance-based evolutionary algorithms can effectively address multiobjective optimization problems (MOPs). However, when dealing with many-objective optimization problems with more than three objectives (MaOPs), the Pareto dominance relationships cannot effectively distinguish the nondominated solutions in high-dimensional spaces. With the increase of the number of objectives, the proportion of dominance-resistant solutions (DRSs) in the population rapidly increases, which leads to insufficient selection pressure. In this paper, to address the challenges on MaOPs, a knee point-driven many-objective evolutionary algorithm with adaptive switching mechanism (KPEA) is proposed. In KPEA, the knee points determined by an adaptive strategy are introduced for not only mating selection but also environmental selection, which increases the probability of generating excellent offspring. In addition, to remove dominance-resistant solutions (DRSs) in the population, an interquartile range method is adopted, which enhances the selection pressure. Moreover, a novel adaptive switching mechanism between angle-based selection and penalty for selecting solutions is proposed, which is aimed at achieving a balance between convergence and diversity. To validate the performance of KPEA, it is compared with five state-of-the-art many-objective evolutionary algorithms. All algorithms are evaluated on 20 benchmark problems, i.e., WFG1-9, MaF1, and MaF4-13 with 3, 5, 8, and 10 objectives. The experimental results demonstrate that KPEA outperforms the compared algorithms in terms of HV and IGD in most of the test instances. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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16. Mathematical Modeling of Giardiasis Transmission Dynamics with Control Strategies in the Presence of Carriers.
- Author
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Liana, Yustina A. and Chuma, Furaha Michael
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INFECTIOUS disease transmission , *GIARDIASIS , *BASIC reproduction number , *MATHEMATICAL models , *RECREATIONAL mathematics - Abstract
Giardiasis is among the ignored zoonotic illnesses accorded by the World Health Organization that is caused by Giardia duodenalis. The disease is ignored regardless of the harm it causes to people and other creatures. In this paper, a mathematical model for giardiasis illness transmission is formed, which considers sickness carriers and control measures such as screening, treatment, and sanitation of the environment around people. In the assessment, the basic reproduction number, R 0 , which is used for analyzing the local stability of the equilibria is determined using the state-of-the-art next-generation matrix, while the Metzler constancy speculation is used to show the overall adequacy of the global stability of the equilibrium point free from the disease. In addition, a Lyapunov function has been used to study the stability of the endemic equilibrium point. The assessment of parameters is performed to explore the limits that significantly influence the transmission components of the disease disorders using the normalizing sensitivity index method. The result revealed that the recruitment rate is the most sensitive limit to the reproduction number. The environment-human interaction parameter is the second influential factor in the transmission of giardiasis in the community. In the same manner, the outcomes recommend that carriers assume an expected part in the rate of giardiasis subsequently; disregarding them could risk endeavors to control the pestilence. Besides, the mathematical recreation of the model shows that a mix of each of the three interventions fundamentally affects the control of giardiasis. In this way, we advise implementing the strategies simultaneously in endemic areas to effectively stop the spread of the giardiasis disease in humans. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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17. Mathematical Modeling and Stability Analysis of Systemic Risk in the Banking Ecosystem.
- Author
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Irakoze, Irène, Nahayo, Fulgence, Ikpe, Dennis, Gyamerah, Samuel Asante, and Viens, Frederi
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SYSTEMIC risk (Finance) , *RISK assessment , *BANKING industry , *MATHEMATICAL models , *FINANCIAL risk , *ECOSYSTEMS - Abstract
This paper investigates the dynamics of systemic risk in banking networks by analyzing equilibrium points and stability conditions. The focus is on a model that incorporates interactions among distressed and undistressed banks. The equilibrium points are determined by solving a reduced system of equations, considering both homogeneous and heterogeneous scenarios. Local and global stability analyses reveal conditions under which equilibrium points are stable or unstable. Numerical simulations further illustrate the dynamics of systemic risk, while the theoretical findings offer insights into the behavior of distressed banks under varying conditions. Overall, the model enhances our understanding of systemic financial risk and offers valuable insights for risk management and policymaking in the banking sector. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
18. Mapping Connectivity Patterns: Degree-Based Topological Indices of Corona Product Graphs.
- Author
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Ali, Nasir, Kousar, Zaeema, Safdar, Maimoona, Tolasa, Fikadu Tesgara, and Suleiman, Enoch
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MOLECULAR connectivity index , *TEXTURE mapping , *MOLECULAR structure , *MOLECULAR graphs , *GRAPH theory , *COMPLETE graphs , *RAMSEY numbers - Abstract
Graph theory (GT) is a mathematical field that involves the study of graphs or diagrams that contain points and lines to represent the representation of mathematical truth in a diagrammatic format. From simple graphs, complex network architectures can be built using graph operations. Topological indices (TI) are graph invariants that correlate the physicochemical and interesting properties of different graphs. TI deal with many properties of molecular structure as well. It is important to compute the TI of complex structures. The corona product (CP) of two graphs G and H gives us a new graph obtained by taking one copy of G and V G copies of H and joining the i th vertex of G to every vertex in the i th copy of H. In this paper, based on various CP graphs composed of paths, cycles, and complete graphs, the geometric index (GA) and atom bond connectivity (ABC) index are investigated. Particularly, we discussed the corona products P s ⨀ P t , C t ⨀ C s , K t ⊙ K s , K t ⊙ P s , and P s ⊙ K t and GA and ABC index. Moreover, a few molecular graphs and physicochemical features may be predicted by considering relevant mathematical findings supported by proofs. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
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19. INEH-VNS Algorithm Solved Automatic Production System Scheduling Problem under Just-in-Time Environment.
- Author
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Qingxiang, Li, Xiaofei, Zhao, Yude, He, and Shaojun, Yin
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AUTOMATION , *PRODUCTION scheduling , *ALGORITHMS , *TARDINESS - Abstract
Automatic production system scheduling problem under a just-in-time environment is researched in this paper. The automatic production system is composed of many tanks and one robotic, the tank of the researched problem is responsible for processing the job, and the robotic moves the job from one tank to the other tank. The difference between the researched problem and the classic shop scheduling problem is that the former must consider job scheduling and the robotic move sequence, but the latter considers only job scheduling. For optimizing simultaneously job scheduling and robotic move sequence in the proposed problem and minimizing total earliness/tardiness, an improved NEH (Nawaz-Enscore-Ham) and variable search (INEH-VNS) algorithm are developed. In the proposed method, firstly, to obtain initial solution, an improved NEH is shown. Secondly, for computing value of the objective function, the double procedure method is constructed. Thirdly, according to the properties of the proposed problem, three neighborhood structures, adjacent exchange, random insertion, and job exchange, are investigated. To test the performance of the INEH-VNS, 100 instances are randomly generated. When the run time is the same, compared with CPLEX 12.5, the INEH-VNS algorithm can find high-quality approximate optimal solution, a special big scale. Compared with the G-VNS algorithm, the average improvement rate of the approximate optimal solution is 45.9%, and the average stability rate of the INEH-VNS algorithm enhances 75.04%. That is to say, the INEH-VNS algorithm is outstanding and more effective. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
20. On the Global Asymptotic Stability and 4-Period Oscillation of the Third-Order Difference Equation.
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Erdogan, M. E.
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GLOBAL asymptotic stability , *DIFFERENCE equations , *OSCILLATIONS , *REAL numbers - Abstract
The main objective of this paper is to study the global behavior and oscillation of the following third-order rational difference equation x n + 1 = α x n x n − 1 x n − 2 / β x n − 1 2 + γ x n − 2 2 , where the initial conditions x − 2 , x − 1 , x 0 are nonzero real numbers and α , β , γ are positive constants such that α ≤ β + γ. Visual examples supporting solutions are given at the end of the study. The figures are found with the help of MATLAB. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
21. Theoretical Error Analysis of Hybrid Finite Difference–Asymptotic Interpolation Method for Non-Newtonian Fluid Flow.
- Author
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Mahadi, Shafaruniza, Yeak, Su Hoe, Arbin, Norazam, and Salah, Faisal
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FLUID flow , *NON-Newtonian fluids , *FINITE difference method , *UNSTEADY flow , *INTERPOLATION , *NON-Newtonian flow (Fluid dynamics) , *ERROR analysis in mathematics - Abstract
In this paper, we utilized a hybrid method for the unsteady flow of the non-Newtonian third-grade fluid that combines the finite difference with the asymptotic interpolation method. This hybrid method is used to satisfy the semiunbound domain condition of the fluid flow's length approaching infinity. The primary issue with this research is how much of the hybrid approach's error may be accepted to guarantee that the method is significant. This paper discussed theoretical error analysis for numerical solutions, including the range and norm of error. The perturbation method's concept is used to assess the hybrid method's error. It is discovered that the hybrid approach's relative error norm is lower than that of the finite difference method. In terms of the error standard, the hybrid approach is more consistent. Error analysis is performed to check for the accuracy as well as the platform for variable mesh size finite difference method in the future research. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
22. Comparative Analysis of the Prox Penalty and Bregman Algorithms for Image Denoising.
- Author
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Bougueroua, Soulef and Daili, Nourreddine
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IMAGE reconstruction , *IMAGE processing , *RANDOM noise theory , *COMPARATIVE studies , *ALGORITHMS , *IMAGE denoising - Abstract
Image restoration is an interesting ill-posed problem. It plays a critical role in the concept of image processing. We are looking for an image that is as near to the original as possible among images that have been skewed by Gaussian and additive noise. Image deconstruction is a technique for restoring a noisy image after it has been captured. The numerical results achieved by the prox-penalty method and the split Bregman algorithm for anisotropic and isotropic TV denoising problems in terms of image quality, convergence, and signal noise rate (SNR) are compared in this paper. It should be mentioned that isotropic TV denoising is faster than anisotropic. Experimental results indicate that the prox algorithm produces the best high-quality output (clean, not smooth, and textures are preserved). In particular, we obtained (21.4, 21) the SNR of the denoising image by the prox for sigma 0.08 and 0.501, such as we obtained (10.0884, 10.1155) the SNR of the denoising image by the anisotropic TV and the isotropic TV for sigma 0.08 and (-1.4635, -1.4733) for sigma 0.501. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
23. A Mathematical Model of the Dynamics of Coffee Berry Disease.
- Author
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Nyaberi, H. O., Mutuku, W. N., Malonza, D. M., and Gachigua, G. W.
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CONTINUOUS time models , *MATHEMATICAL models , *COFFEE plantations , *BASIC reproduction number , *ORDINARY differential equations , *COFFEE - Abstract
Coffee berry disease (CBD) is a fungal disease caused by Colletotrichum kahawae. CBD is a major constraint to coffee production to Kenya and Africa at large. In this research paper, we formulate a mathematical model of the dynamics of the coffee berry disease. The model consists of coffee plant population in a plantation and Colletotrichum kahawae pathogen population. We derived the basic reproduction number R k 0 , and analyzed the dynamical behaviors of both disease-free equilibrium and endemic equilibrium by the theory of ordinary differential equations. Using the MATLAB ode45 solver, we carried out numerical simulation, and the findings are consistent with the theoretical results. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
24. The Picture on the Presentation of Direct Product Group of Two Cyclic Groups.
- Author
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Yanita, Yanita and Rudianto, Budi
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COMMUTATORS (Operator theory) , *PICTURES , *COMMUTATION (Electricity) - Abstract
A picture in a group presentation is a geometric configuration with an arrangement of discs and arcs within a boundary disc. The drawing of this picture does not have to follow a particular rule, only using the generator as discs and the relation as arcs. It will form a picture label pattern if drawn with a particular rule. This paper discusses the label pattern of a picture in the presentation of direct product groups. Direct product presentation is used with two cyclic groups, ℤ p and ℤ q where p , q ∈ ℤ + and p , q ≥ 2. The method for forming a picture label pattern is to arrange the first generator in the initial arrangement, compile a second generator, and add a number of commutators. Furthermore, the pattern is used to calculate the length of the label on the picture. It is obtained that the picture's label is a q − 1 b n a b q − n and the length of the label is p + 2 n − q , where n is the number of commutator discs. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
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25. Valuing Equity-Linked Death Benefits on Multiple Life with Time until Death following a Kn Distribution.
- Author
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Adékambi, Franck and Konzou, Essomanda
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SURVIVORS' benefits , *MARGINAL distributions , *WIENER processes , *LIFE insurance - Abstract
The purpose of this paper is to investigate the valuation of equity-linked death benefit contracts and the multiple life insurance on two heads based on a joint survival model. Using the exponential Wiener process assumption for the stock price process and a K n distribution for the time until death, we provide explicit formulas for the expectation of the discounted payment of the guaranteed minimum death benefit products, and we derive closed expressions for some options and numerical illustrations. We investigate multiple life insurance based on a joint survival using the bivariate Sarmanov distribution with K n (i.e., the Laplace transform of their density function is a ratio of two polynomials of degree at most) marginal distributions. We present analytical results of the joint-life status. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
26. Exact Controllability for a Class of Fractional Semilinear System of Order 1<q<2 with Instantaneous and Noninstantaneous Impulses.
- Author
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Chu, Yunhao and Liu, Yansheng
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CONTROLLABILITY in systems engineering , *CARLEMAN theorem , *SEMILINEAR elliptic equations , *MEASUREMENT - Abstract
This paper is mainly concerned with the existence of mild solutions and exact controllability for a class of fractional semilinear system of order q ∈ 1 , 2 with instantaneous and noninstantaneous impulses. First, combining the Kuratowski measure of noncompactness and the Mönch fixed point theorem, we investigated the existence result for the considered system. It is remarkable that our assumptions for impulses and the nonlinear term are weaker than the Lipschitz conditions. Next, on this basis, the exact controllability for the considered system is determined. In the end, an example is provided to support the main findings. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
27. Estimation of Spatially Varying Parameters with Application to Hyperbolic SPDES.
- Author
-
Angwenyi, David
- Subjects
- *
MONTE Carlo method , *COST functions , *MAXIMUM likelihood statistics , *WAVE equation , *MARKOV chain Monte Carlo , *SIGNAL processing , *PARAMETER estimation - Abstract
Parameter estimation is a growing area of interest in statistical signal processing. Some parameters in real-life applications vary in space as opposed to those that are static. Most common methods in estimating parameters involve solving an optimization problem where the cost function is assembled variously, for example, maximum likelihood and maximum a posteriori methods. However, these methods do not have exact solutions to most real-life problems. It is for this reason that Monte Carlo methods are preferred. In this paper, we treat the estimation of parameters which vary with space. We use the Metropolis-Hastings algorithm as a selection criterion for the maximum filter likelihood. Comparisons are made with the use of joint estimation of both the spatially varying parameters and the state. We illustrate the procedures employed in this paper by means of two hyperbolic SPDEs: the advection and the wave equation. The Metropolis-Hastings procedure registers better estimates. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
28. Computing some Laplacian Coefficients of Forests.
- Author
-
Ghalavand, Ali and Ashrafi, Ali Reza
- Subjects
- *
POLYNOMIALS , *FINITE, The , *RANDOM forest algorithms , *LAPLACIAN matrices - Abstract
Let G be a finite simple graph with Laplacian polynomial ψ G , λ = ∑ k = 0 n − 1 n − k c k λ k . In an earlier paper, the coefficients c n − 4 and c n − 5 for forests with respect to some degree-based graph invariants were computed. The aim of this paper is to continue this work by giving an exact formula for the coefficient c n − 6 . [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
29. Effect of Vaccination and Culling on the Dynamics of Rabies Transmission from Stray Dogs to Domestic Dogs.
- Author
-
Hailemichael, Demsis Dejene, Edessa, Geremew Kenassa, and Koya, Purnachandra Rao
- Subjects
- *
DOGS , *RABIES , *FERAL dogs , *INFECTIOUS disease transmission , *VACCINATION , *RABIES virus , *BIRTH rate - Abstract
In this paper, the population dynamics of rabies-infected dogs are studied. The mathematical model is constructed by dividing the dog population into two categories: stray dogs and domestic dogs. On the other hand, the rabies virus is likely to spread in both populations. In the current model, disease-controlling strategies such as vaccination and culling are applied, and their impact is studied. Both subpopulations of susceptible individuals are vaccinated to control disease spread. The current study assumes that stray dogs can transmit rabies to domestic dogs but not the other way around. Because domestic dogs are under the control of their owners, they are well vaccinated. The model is medically and analytically correct because the findings are idealistic and limited. The next-generation matrix technique is used to compute the effective reproductive amount, and also, each parameter is subjected to sensitivity analysis. The equilibrium point free from disease is discovered, demonstrating that it was asymptotically steady locally and globally. A conditionally global asymptotically stable point of endemic equilibrium is also discovered using the Lyapunov function method. The numerical simulation, which makes use of approximations for parameter values, shows that the most efficient method for avoiding rabies transmission is a combination of vaccination and the culling of infected stray dogs. Using MATLAB's ode45, this numerical simulation investigation was carried out. Our early findings indicated that the annual dog birth rate is a critical factor in influencing the occurrence of rabies. In the body of the paper, the findings and discussion are organized logically. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
30. 2D Sin-Cos-Henon Map for Color Image Encryption with High Security.
- Author
-
Cheng, Zhiqiang, Wang, Wencheng, Dai, Yuezhang, and Li, Lun
- Subjects
- *
IMAGE encryption , *COLOR , *SECURITY management - Abstract
In this paper, a high security color image encryption algorithm is proposed by 2D Sin-Cos-Hénon (2D-SCH) system. A new two-dimensional chaotic system which is 2D-SCH. This system is hyperchaotic. The use of the 2D-SCH, a color image encryption algorithm based on random scrambling and localization diffusion, is proposed. First, the secret key is generated by SHA512 through plaintext. As the initial value of the 2D-SCH system, the secret key is used to generate chaotic sequences. Then, the random scrambling is designed based on chaotic sequences. Finally, a pair of initial points is generated by the secret key; the image diffuses around this point. The ciphertext is obtained by a double encryption. Different from the traditional encryption algorithm, this paper encrypts three channels of color image simultaneously, which greatly improves the security of the algorithm. Simulation results show that the algorithm can resist various attacks. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
31. Modeling and Optimal Control Analysis Applied to Real Cases of COVID-19 Pandemic with Double Dose Vaccination in Ethiopia.
- Author
-
Legesse, Fekadu Mosisa, Rao, Koya Purnachandra, and Keno, Temesgen Duressa
- Subjects
- *
COVID-19 pandemic , *INFECTIOUS disease transmission , *SARS-CoV-2 , *VACCINATION , *LYAPUNOV functions - Abstract
The novel coronavirus is a recently discovered member of one of the largest families of viruses with symptoms ranging from a simple cold to excruciating respiratory agony. In the present paper, a deterministic mathematical model is formulated to estimate the transmission dynamics of COVID-19 with the inclusion of control strategies like (i) double-dose vaccination, (ii) prevention, and (iii) treatment. In addition, instead of considering all infectious humans as one unit, we separate them into symptomatic and asymptomatic groups, and the impact is analyzed. This separation is meaningful because various reports indicate that the asymptomatic cases will spread the disease more than the symptomatic cases. The model is proved to be mathematically well-posed and biologically meaningful by showing positivity and boundedness of the solution using the appropriate initial conditions. For the reproduction number, a parametric formula is constructed, and also the associated numerical value is calculated from the reported real data in Ethiopia. Moreover, disease-free and endemic equilibria are determined, and their local and global stabilities are discussed using the Lyapunov function technique. These equilibria are found to be locally asymptotically stable if R 0 < 1 and R 0 > 1 , respectively. Following the model fitting and estimation of the parameter values, sensitivity analysis was performed in order to analyze the impact of each parameter on transmission dynamics. In other words, this study can be used to evaluate how major model parameters affect transmission dynamics and control. Utilizing Pontryagin's maximal principle, the best control measures are implemented with the aim of lowering the burdens associated with infection, prevention, and treatment. To comprehend and visualize the impact of control techniques on the development of the disease and to illustrate the analytical findings generated in this study, numerical simulation studies are conducted. Finally, the output of the study illustrates that adhering to all the control strategies has a big impact on minimizing the transmission of the disease in society. Which means that if the control strategies are well managed by the concerned body, then the burden of the disease is reduced quickly in the Ethiopian population. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
32. Asymptotic Expansions for Large Degree Tangent and Apostol-Tangent Polynomials of Complex Order.
- Author
-
Corcino, Cristina B., Corcino, Roberto B., and Casquejo, Jeremar
- Subjects
- *
POLYNOMIALS , *ASYMPTOTIC expansions - Abstract
This paper provides asymptotic expansions for large values of n of tangent T n μ z and Apostol-tangent T n μ z ; λ polynomials of complex order. The derivation is done using contour integration with the contour avoiding branch cuts. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
33. Mathematical Modeling and Analysis on the Effects of Surgery and Chemotherapy on Lung Cancer.
- Author
-
Ullah, Md. Ahsan and Mallick, Uzzwal Kumar
- Subjects
- *
CANCER chemotherapy , *MATHEMATICAL analysis , *LUNG cancer , *LUNG surgery , *MATHEMATICAL models - Abstract
Lung cancer is the biggest cause of cancer mortality worldwide and a major impediment to extending life expectancy. In comparison to other cancers, it has a relatively poor survival rate. In this paper, we have developed a mathematical model for lung cancer based on biological phenomena using nonlinear ordinary differential equations and analyzed it both analytically and numerically. According to the findings, CD8+ T cells and dendritic cells have a role in tumor cell variety. Surgery and chemotherapy have been used as treatment options, and we have observed that three doses of chemotherapy after surgery had the greatest results after examining several treatment options. During the treatment period, the cycle of each chemotherapy has been taken every 4 weeks, and the first dose has been taken after 28 days of surgery. Finally, we have evaluated the various starting dates for the best treatment choice and discovered that the patient who begins treatment sooner has a better probability of surviving. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
34. Error Bounds for Approximations Using Multichannel Deep Convolutional Neural Networks with Downsampling.
- Author
-
Liu, Xinling and Hou, Jingyao
- Subjects
- *
CONVOLUTIONAL neural networks , *APPROXIMATION error , *DEEP learning , *SOBOLEV spaces , *MATHEMATICAL convolutions - Abstract
Deep learning with specific network topologies has been successfully applied in many fields. However, what is primarily called into question by people is its lack of theoretical foundation investigations, especially for structured neural networks. This paper theoretically studies the multichannel deep convolutional neural networks equipped with the downsampling operator, which is frequently used in applications. The results show that the proposed networks have outstanding approximation and generalization ability of functions from ridge class and Sobolev space. Not only does it answer an open and crucial question of why multichannel deep convolutional neural networks are universal in learning theory, but it also reveals the convergence rates. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
35. Hydromagnetic Flow of Two Immiscible Couple Stress Fluids through Porous Medium in a Cylindrical Pipe with Slip Effect.
- Author
-
Bitla, Punnamchandar and Kore, Yitagesu Daba
- Subjects
- *
POROUS materials , *LIQUID-liquid interfaces , *FLUIDS , *POISEUILLE flow , *FLOW velocity , *REYNOLDS number , *SLIP flows (Physics) - Abstract
In this study, the steady hydromagnetic flow of two immiscible couple stress fluids through a uniform porous medium in a cylindrical pipe with slip effect is investigated analytically. Essentially, the flow system is divided into two regions, region I and region II, which occupy the core and periphery of the system, respectively. The flow is driven by a constant pressure gradient applied in a direction parallel to the cylinder's axis, and an external uniform magnetic field is applied in the direction perpendicular to the direction of fluid motion. Instead of the classical no-slip condition, the slip velocity along with vanishing couple stress boundary conditions is taken on the surface of the rigid cylinder, and continuity conditions of velocity, vorticity, shear stress, and couple stress are imposed at the fluid-fluid interface. The governing equations are modeled using the fully developed flow conditions. The resulting differential equations governing the flow in the two regions are converted to nondimensional forms using appropriate dimensionless variables. The nondimensional equations are solved analytically, and closed-form expressions for the flow velocity, flow rate, and stresses are derived in terms of the Bessel functions. The impacts of several parameters pertaining to the flow such as the magnetic number, couple stress parameters, Darcy number, viscosity ratio, Reynolds number, and slip parameter on the velocities in respective regions are examined and illustrated through graphs. The flow rate's numerical values are also calculated for different fluid parameters and displayed in tabular form. It is found that increasing the magnetic number, viscosity ratio, Reynolds number, and slip parameters decreases the velocities of the fluids whereas increasing the couple stress parameter, Darcy number, and pressure gradient increases fluid velocities. The results obtained in this paper show an excellent agreement with the already existing results in the literature as limiting cases. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
36. Positive Solutions for Third-Order Boundary Value Problems with the Integral Boundary Conditions and Dependence on the First-Order Derivatives.
- Author
-
Yang, Fei, Lin, Yuanjian, Zhang, Juan, and Lou, Quanfu
- Subjects
- *
BOUNDARY value problems , *CONTINUOUS functions - Abstract
In this paper, by the use of a new fixed point theorem and the Green function of BVPs, the existence of at least one positive solution for the third-order boundary value problem with the integral boundary conditions is considered,where there is a nonnegative continuous function. Finally, an example which to illustrate the main conclusions of this paper is given. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
37. A Fast and Efficient Estimation of the Parameters of a Model of Accident Frequencies via an MM Algorithm.
- Author
-
Geraldo, Issa Cherif, Katchekpele, Edoh, and Kpanzou, Tchilabalo Abozou
- Subjects
- *
PARAMETER estimation , *ALGORITHMS , *STATISTICAL models - Abstract
In this paper, we consider a multivariate statistical model of accident frequencies having a variable number of parameters and whose parameters are dependent and subject to box constraints and linear equality constraints. We design a minorization-maximization (MM) algorithm and an accelerated MM algorithm to compute the maximum likelihood estimates of the parameters. We illustrate, through simulations, the performance of our proposed MM algorithm and its accelerated version by comparing them to Newton-Raphson (NR) and quasi-Newton algorithms. The results suggest that the MM algorithm and its accelerated version are better in terms of convergence proportion and, as the number of parameters increases, they are also better in terms of computation time. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
38. Characterizations of the Generalized MPCEP Inverse of Rectangular Matrices.
- Author
-
Yao, Jiaxuan, Liu, Xiaoji, and Jin, Hongwei
- Subjects
- *
COMPLEX matrices , *LINEAR systems , *MATRIX inversion , *EQUATIONS - Abstract
In this paper, we introduce a new generalized inverse, called the G-MPCEP inverse of a complex matrix. We investigate some characterizations, representations, and properties of this new inverse. Cramer's rule for the solution of a singular equation A x = B is also presented. Moreover, the determinantal representations for the G-MPCEP inverse are studied. Finally, the G-MPCEP inverse being used in solving appropriate systems of linear equations is established. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
39. 3D Modeling of Mine Protection Complex Steel Structure Based on BIM Technology.
- Author
-
Li, Fenhong, Wang, Zaisheng, Pang, Chongan, and Yang, Haiping
- Subjects
- *
STEEL , *ULTIMATE strength , *COLUMNS , *THREE-dimensional modeling , *DESIGN protection - Abstract
The objective of this paper is to study the antidamage ability of beam column joints in complex steel structures under external forces and to improve the safety of such structures. In this study, a three-dimensional model of complex steel structure based on BIM technology is proposed by analyzing and calculating the ultimate strength of complex steel structure for mine protection. The vibration control algorithm of complex steel structure for mine protection is designed, and the boundary elastic constraint conditions are determined. According to the constraint conditions, the vibration characteristics of complex steel structures for mining are analyzed. The experimental results show that the maximum displacement of the design model is reduced by half compared with that before optimization, which can meet the design requirements. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
40. The Dynamics of a Delayed Ecoepidemiological Model with Nonlinear Incidence Rate.
- Author
-
Hussien, Reem Mudar and Naji, Raid Kamel
- Subjects
- *
HOPF bifurcations , *INFECTIOUS disease transmission , *COMPUTER simulation - Abstract
In this paper, the general framework for calculating the stability of equilibria, Hopf bifurcation of a delayed prey-predator system with an SI type of disease in the prey population, is investigated. The impact of the incubation period delay on disease transmission utilizing a nonlinear incidence rate was taken into account. For the purpose of explaining the predation process, a modified Holling type II functional response was used. First, the existence, uniform boundedness, and positivity of the solutions of the considered model system, along with the behavior of equilibria and the existence of Hopf bifurcation, are studied. The critical values of the delay parameter for which stability switches and the nature of the Hopf bifurcation by using normal form theory and center manifold theorem are identified. Additionally, using numerical simulations and a hypothetical dataset, various dynamic characteristics are discovered, including stability switches, chaos, and Hopf bifurcation scenarios. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
41. Mathematical Model for Crimes in Developing Countries with Some Control Strategies.
- Author
-
Mataru, Bilali, Abonyo, Okelo Jeconiah, and Malonza, David
- Subjects
- *
MATHEMATICAL models , *CRIME , *EPIDEMIOLOGICAL models , *UNEMPLOYMENT ,DEVELOPING countries - Abstract
Crime is one among the most challenging problems in most developing countries in which unemployment is among the causes. Not all kind of crimes can be eradicated indeed; this paper is intended to contribute on eradication of unemployment-related crimes in the developing countries by proposing a deterministic mathematical model of unemployment-crime dynamics including vocational training and employment as control measures for crime. The study adopts the epidemiological model concepts on model formulation and model analysis while considering unemployment as main driver of crime. The basic properties of the model are analyzed, and well-posed of the model is established by using the Lipschitz condition. The next-generation matrix is used to obtain the criminal reproduction number which help to derive the conditions for local and global stability of the model. Moreover, the existence of backward and forward bifurcation when the crime reproduction number is equal to one was analyzed by center manifold theory. Simulations of the model are carried out to validate the theoretical part of the model and demonstrate vocational training, and employment strategies are more effective in combating crime when applied simultaneously. The findings suggest that unemployment problem should be addressed in order to reduce the number of unemployed individuals in joining the criminal activities. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
42. Asumu Fractional Derivative Applied to Edge Detection on SARS-COV2 Images.
- Author
-
Nchama, Gustavo Asumu Mboro, Alfonso, Leandro Daniel Lau, Morales, Roberto Rodríguez, and Aneke, Ezekiel Nnamere
- Subjects
- *
SARS-CoV-2 , *CLASSIFICATION algorithms , *SET theory , *EDGES (Geometry) , *ARTIFICIAL intelligence , *DIGITAL images - Abstract
Edge detection consists of a set of mathematical methods which identifies the points in a digital image where image brightness changes sharply. In the traditional edge detection methods such as the first-order derivative filters, it is easy to lose image information details and the second-order derivative filters are more sensitive to noise. To overcome these problems, the methods based on the fractional differential-order filters have been proposed in the literature. This paper presents the construction and implementation of the Prewitt fractional differential filter in the Asumu definition sense for SARS-COV2 image edge detection. The experiments show that these filters can avoid noise and detect rich edge details. The experimental comparison show that the proposed method outperforms some edge detection methods. In the next paper, we are planning to improve and combine the proposed filters with artificial intelligence algorithm in order to program a training system for SARS-COV2 image classification with the aim of having a supplemental medical diagnostic. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
43. The Eigenspace Spectral Regularization Method for Solving Discrete Ill-Posed Systems.
- Author
-
Wireko, Fredrick Asenso, Barnes, Benedict, Sebil, Charles, and Ackora-Prah, Joseph
- Subjects
- *
SINGULAR value decomposition , *DISCRETE systems , *CIRCULANT matrices , *SPARSE matrices , *LEAST squares - Abstract
This paper shows that discrete linear equations with Hilbert matrix operator, circulant matrix operator, conference matrix operator, banded matrix operator, TST matrix operator, and sparse matrix operator are ill-posed in the sense of Hadamard. Gauss least square method (GLSM), QR factorization method (QRFM), Cholesky decomposition method (CDM), and singular value decomposition (SVDM) failed to regularize these ill-posed problems. This paper introduces the eigenspace spectral regularization method (ESRM), which solves ill-posed discrete equations with Hilbert matrix operator, circulant matrix operator, conference matrix operator, and banded and sparse matrix operator. Unlike GLSM, QRFM, CDM, and SVDM, the ESRM regularizes such a system. In addition, the ESRM has a unique property, the norm of the eigenspace spectral matrix operator κ K = K − 1 K = 1. Thus, the condition number of ESRM is bounded by unity, unlike the other regularization methods such as SVDM, GLSM, CDM, and QRFM. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
44. On a Solution of a Third Kind Mixed Integro-Differential Equation with Singular Kernel Using Orthogonal Polynomial Method.
- Author
-
Alalyani, Ahmad, Abdou, M. A., and Basseem, M.
- Subjects
- *
ALGEBRAIC equations , *FREDHOLM equations , *INTEGRAL equations , *ORTHOGONAL polynomials , *SEPARATION of variables , *INTEGRAL operators , *INTEGRO-differential equations - Abstract
This paper deals with the solution of a third kind mixed integro-differential equation (MIDE) in displacement type in space L 2 − 1 , 1 × C 0 , T , T < 1. The singular kernel is modified to take a logarithmic form, while the kernels of time are continuous and positive functions. Using the separation of variables technique, we have a system of Fredholm integral equations (FIEs) that can be transformed into an algebraic system after using orthogonal polynomials. In all the previous researchers' works, the time periods were divided, and the mixed equation transformed into an algebraic system of FIEs. While when using the separation method, we are able to obtain FIE with time coefficients, and these functions are described as an integral operator in time. Thus, we can study the behavior of the solution with the time dimension in a broader and deeper than the previous one. Some examples are given and discussed to show the performance and efficiency of the proposed methods. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
45. Modelling the Impact of Human Population and Its Associated Pressure on Forest Biomass and Forest-Dependent Wildlife Population.
- Author
-
Fanuel, Ibrahim M., Kajunguri, Damian, and Moyo, Francis
- Subjects
- *
FOREST biomass , *ANIMAL populations , *SOCIOECONOMIC factors , *ECONOMIC status , *MATHEMATICAL models , *CONSUMPTION (Economics) - Abstract
Mathematical models have been widely used to explain the system originating from human-nature interaction, investigate the impacts of various components, and forecast system behaviour. This paper provides a profound reference to the current state of the art regarding the application of mathematical models to study the impact of human population and population pressure on forest biomass and forest-dependent wildlife. The review focused on two aspects, namely, model formulation and model analysis. In model formulation, the review revealed that socioeconomic status influences forest resource consumption patterns, thus, stratification of the human population based on economic status is a critical phenomenon in modelling human-nature interactions; however, this component has not been featured in the reviewed models. Regarding model analysis, in most of the reviewed work, single parameter approach was utilized to perform uncertainty quantification of the model parameter; this approach has been proven to be inadequate in measuring the uncertainty and sensitivity of the parameter. Thus, the use of correlation or variance based methods, which are multidimensional parameter space methods are of significant importance. Generally, despite the limitations of many assumptions in mathematical modelling, it is revealed that mathematical models demonstrate the ability to handle complex systems originating from interactions between humans and nature. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
46. Chromatic Schultz and Gutman Polynomials of Jahangir Graphs J2,m and J3,m.
- Author
-
Shaheen, Ramy, Mahfud, Suhail, and Alhawat, Qays
- Subjects
- *
MOLECULAR connectivity index , *GRAPH connectivity , *POLYNOMIALS - Abstract
Topological polynomial and indices based on the distance between the vertices of a connected graph are widely used in the chemistry to establish relation between the structure and the properties of molecules. In a similar way, chromatic versions of certain topological indices and the related polynomial have also been discussed in the recent literature. In this paper, we present the chromatic Schultz and Gutman polynomials and the expanded form of the Hosoya polynomial and chromatic Schultz and Gutman polynomials, and then we derive these polynomials for special cases of Jahangir graphs. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
47. Research on a New Control System Based on L1 Adaptive Control Scheme for the Voice Coil Motor.
- Author
-
Jing, Huaiguo, Li, Ying, Li, Bo, Huang, Shuo, Zhan, RuiDian, Li, Hao, and Zhang, Xuexi
- Subjects
- *
SERVOMECHANISMS , *TENNIS tournaments , *SPORTS competitions , *ADAPTIVE control systems , *TENNIS balls , *CLOSED loop systems - Abstract
With the continuous development of voice coil motors, it has also been widely used in today's sports competitions. For example, the Hawk-Eye system in tennis matches uses voice coil motors to focus on the camera to capture the trajectory of the tennis ball. Therefore, in order to better solve the problem of dynamic parameter uncertainty, external load disturbance, and tracking control of the voice coil motor servo system in motion, this paper proposes for the first time the strategy of using L1 adaptive control algorithm to control the voice coil motor servo system. First, it briefly analyzes the working principle and control method of the voice coil motor, and then constructs the uncertain parameter model according to the mathematical model of the voice coil motor. The closed-loop system of voice coil motor is simulated and analyzed by L1 adaptive controller. The results show that the L1 adaptive control method effectively suppresses the high-frequency interference caused by the voice coil motor in operation, can control the tracking error to gradually converge and so the tracking effect is better, and has strong robustness to the perturbation of system parameters. It can be applied to voice coil motor servo control. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
48. Mathematical Modeling of Wax Deposition in Field-Scale Crude Oil Pipeline Systems.
- Author
-
Ochieng, Francis Oketch, Kinyanjui, Mathew Ngugi, Abonyo, Jeconia Okelo, and Kiogora, Phineas Roy
- Subjects
- *
PETROLEUM pipelines , *PETROLEUM , *PIPELINE transportation , *PRECIPITATION (Chemistry) kinetics , *MATHEMATICAL models , *WAXES , *THERMAL insulation - Abstract
The formation of solid wax crystals, which interlock and form a gel-like layer on the inner wall of the crude oil pipeline, influences the transportation of waxy crude oil. The deposited layer grows continuously and hardens during the oil transportation, reducing the effective inside diameter of the crude oil pipeline and the flow rate. In extreme cases, the deposited layer may block the crude oil pipeline leading to a loss of production and capital investment. In this paper, wax deposition from multiphase flow in field-scale oil pipeline transport systems has been studied. The novelty of this work is to develop a mathematical model that incorporates water-in-oil emulsions, wax precipitation kinetics, molecular diffusion, and shear dispersion to enable accurate predictions of both the wax deposit growth rate and aging of the deposit. The coupled nonlinear partial differential equations governing the flow are discretized in time by a second-order semi-implicit time discretization scheme based on the Adams-Bashforth and Crank-Nicolson methods, which completely decouples the computation of the governing equations. The resulting temporal schemes are discretized in space by the bivariate spectral collocation method based on Chebyshev-Gauss-Lobatto grid points and simulated in MATLAB software to obtain the profiles of the flow variables. The simulation results are presented in graphical and in tabular forms and discussed. This study found that the deposit thickness is directly proportional to the Reynolds number and inversely proportional to the mass Grashof number, Schmidt number, and Weber number. Deposit aging is rampant during the early stages of wax deposition, after which it stabilizes at a specific value as time elapses. A deposition model to predict the wax deposit thickness and aging is proposed in this study. The findings of this study will help in making informed decisions on the planning of pigging operations, thermal insulation, and other remediation techniques to be applied in controlling wax deposition in field-scale crude oil pipeline systems. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
49. A New Credit and Loan Lending Strategy and Credit in Banking Systems: An Evolutionary Game Theory Approach.
- Author
-
Lashgari, Zohreh, Bahiraie, Alireza, and Eshaghi Gordji, Madjid
- Subjects
- *
LOANS , *BANK loans , *GAME theory , *BANK customers , *CORPORATE banking - Abstract
In this paper, authors offer one novel mathematical model of credit lending to customers based on evolutionary game theory, and the model presents an efficient and realistic approach. The purpose of the article is to examine the evolutionary game between banks and customers for granting facilities and credit. Authors assumed that customers are divided into two types. The first type of customers includes individuals or small and medium enterprises (SME), applying for microloans from the bank. The second type of customers includes corporate banking or large enterprises, applying for large loans from the bank. The relationship between the bank and the customers is a double-sided problem. Banks and customers may trust each other or want to behave opportunistically. The results show that the game has two equilibriums, and the optimal equilibrium, which is the best-case scenario, occurs when customers and bank players tending to keep "honest" and to "credit," respectively. Authors used the evolutionary stable strategy to express the parameters that affect these interactions, and by adjusting some of these parameters, authors move the equilibrium towards the optimal solution of the game. Also, by adjusting these parameters, banks can gain more profitability. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
50. Mathematical Analysis of the Transmission Dynamics of Skin Cancer Caused by UV Radiation.
- Author
-
Parvin, Tahera, Biswas, Md. Haider Ali, and Datta, Bimal Kumar
- Subjects
- *
SKIN cancer , *INFECTIOUS disease transmission , *EFFECT of radiation on skin , *MATHEMATICAL analysis , *ETIOLOGY of cancer - Abstract
Nowadays, skin cancer is a worldwide panic. It is related to ultraviolet radiation. In this paper, we have formulated a SIRS type mathematical model to show the effects of ultraviolet radiation on skin cancer. At first, we have showed the boundedness and positivity of the model solutions to verify the model's existence and uniqueness. The boundedness and positivity gave the solutions of our model bounded and positive, which was very important for real-world situation because in real world, population cannot be negative. Then, we have popped out all the equilibrium points of our model and verified the stability of the equilibrium points. This stability test expressed some physical situation of our model. The disease-free equilibrium point is locally asymptotically stable if R 0 < 1 and if R 0 > 1 , then it is unstable. Again, the endemic equilibrium point is stable, if R 0 > 1 and unstable if R 0 < 1. In order to understand the dynamical behavior of the model's equilibrium points, we examined the phase portrait. We also have observed the sensitivity of the model parameters. After this, we have investigated the different scenarios of bifurcations of the model's parameters. At the set of Hopf bifurcation parameters when infection rate due to UV rays is less than α 1 = 0.01 , proper control may eradicate the existence of disease. From transcritical bifurcation, we can say when recovery rate greater than 1.9, then the disease of skin cancer can be eliminated and when recovery rate less than 1.9 then the disease of skin cancer cannot be eradicated. Finally, numerical analysis is done to justify our analytical findings. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
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