Research Article
Stability of Quadratic Mappings in 2-Banach Spaces and Related Topics
Fadi S. Abu Zenada*
,
Eltayeb A. Abed Elmaged
Issue:
Volume 12, Issue 6, December 2024
Pages:
200-213
Received:
22 August 2024
Accepted:
18 September 2024
Published:
11 November 2024
DOI:
10.11648/j.ajam.20241206.11
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Abstract: Functional analysis is an important branch of mathematics widely used to study the stability of different functional equations. This includes the stability of various quadratic functional equations, which typically involve a specific number of variables to reach results more easily in this field. One of the methods used to study the stability of functional equations is the direct method, which is known for its simplicity in proving the stability of this type of functional equation. In this research paper, we have successfully proven the Hyers-Ulam-Rassias stability of the quadratic functional equation in 2-Banach spaces. Specifically, we have shown that the equation: f(x+y+z)+f(x)+f(y)+f(z)=f(x+y)+f(y+z)+f(x+z) holds true within this context. Our approach involved using either the usual or the direct method to establish this stability. Furthermore, we have also demonstrated the generalized Hyers-Ulam stability of the quadratic functional equation in 2-Banach spaces using the usual process by considering various conditions. This has led to many exciting results and revealed many related applications.
Abstract: Functional analysis is an important branch of mathematics widely used to study the stability of different functional equations. This includes the stability of various quadratic functional equations, which typically involve a specific number of variables to reach results more easily in this field. One of the methods used to study the stability of fu...
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Research Article
Exploring Solvents and Sensitivity of Systems of Linear Equations Arising from Real World Phenomena Via Optimal Successive Over-relaxation Method
Issue:
Volume 12, Issue 6, December 2024
Pages:
214-235
Received:
6 September 2024
Accepted:
4 October 2024
Published:
18 November 2024
Abstract: This study places a significant emphasis on assessing the efficiency of numerical methods, specifically in the context of solving linear equations of the form Ax = b, where A is a square matrix, x is a solvent vector, and b is a column vector representing real-world phenomena. The investigation compares the effectiveness of the Refined Successive Over Relaxation (RSOR) method to the standard Successive Over-relaxation (SOR) method. The core evaluation criteria encompass computational time (in seconds), convergence behavior, and the number of iterations necessary to approximate the solvents of five distinct real-world phenomena: Model Problem 1 (MP1) involving an Electrical Circuit, Model Problem 2 (MP2) focusing on Beam Deflection, Model Problem 3 (MP3) addressing Damped Vibrations of a Stretching Spring, Model Problem 4 (MP4) dealing with Linear Springs and Masses, and Model Problem 5 (MP5) focusing on Temperature Distribution on Heated Plate. The RSOR method generally outperforms the SOR method, particularly with a constant relaxation parameter (ω) in the range 1.0 < ω < 1.2. The RSOR method is favored for its robustness and efficiency with less need for fine-tuning ω, whereas the SOR method can achieve superior performance if the optimal ω is found, although this often requires time-consuming trial and error. Despite the potential for better performance with an optimal ω, the RSOR method’s consistent results make it the more practical choice in many cases. The study also explores the stability of the systems of linear equations arising from these phenomena by calculating their condition numbers (K(A)). More interestingly, the results reveal that all systems MP1 to MP4 exhibit instability when subjected to even modest perturbations, shedding light on potential challenges in their solvents. This research not only underscores the advantages of the RSOR method but also emphasizes the importance of understanding the stability of numerical solvents in the context of real-world problems. Additionally, the results for MP5 demonstrates that tiny changes to the original matrix’s coefficients have no effect on the desired solvent because the perturbed matrix’s condition number is the same as the original matrix’s, making the problem well-structured. The problem becomes ill-conditioned if there is an increase or decrement to the matrix’s coefficients that is bigger than 10−5. In summary, Sparse systems are sensitive to perturbations, resulting in instability. If the tolerance |k(A0i) − k(Ai)| > 10−5 for all positive integers i, then the problem becomes poorly structured.
Abstract: This study places a significant emphasis on assessing the efficiency of numerical methods, specifically in the context of solving linear equations of the form Ax = b, where A is a square matrix, x is a solvent vector, and b is a column vector representing real-world phenomena. The investigation compares the effectiveness of the Refined Successive O...
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Research Article
Modeling the Effects of Social Factors on Population Dynamics Using Age-Structured System
Issue:
Volume 12, Issue 6, December 2024
Pages:
236-245
Received:
23 October 2024
Accepted:
7 November 2024
Published:
28 November 2024
Abstract: The study of demographics is important not only for policy formulation but also for better understanding of human socio-economic characteristics, and assessment of effects of human activities on environmental impact. It is interesting to note that apart from the common population control strategies, industrialization, economic development and improvement of living standards affects population growth parameters. In this paper, an age-structured model was formulated to model population dynamics, and make predictions through simulation using 2019 Kenya population data. The age-structured mathematical model was developed, using partial differential equations on population densities as functions of age and time. The population was structured into 20 clusters each of 5 year interval, and assigned different birth, death rate and transition parameters. Crank-Nicolson numerical scheme was used to simulate the model using the 2019 parameters and population as initial conditions. It was found that; provision of social factors to an efficacy level of δ≥0.75 to a minimum of 70% population leads to a decrease of mortality rate form μold=0.0313 to μnew=0.00184 and an increase in birth rate from βold=0.02639 to βnew=0.05104. This collectively leads to an increase in population by 50% from 38,589,011 to 57,956,100 after 35 years. The initial economic dependency ratio of 1:2, was also improved due to changes in technology and improvement of living standards, to a new ratio of 1:1.14. The graphical presentation in form of a pyramid showed a trend of transition from expansive to constrictive population pyramid. This population structure is stable and remains relatively constant as long as the social factors are maintained.
Abstract: The study of demographics is important not only for policy formulation but also for better understanding of human socio-economic characteristics, and assessment of effects of human activities on environmental impact. It is interesting to note that apart from the common population control strategies, industrialization, economic development and impro...
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