Documents published in Scipedia

• Effects of Fan Installation on Ventilation in Indoor Sports Halls: A Numerical Simulation Study

  Y. Xiao, X. Wu

  Rev. int. métodos numér. cálc. diseño ing. (2025). Vol. 41, (1), 9

  
  

  Abstract

  In this study, numerical simulations were conducted to investigate the changes in air circulation after the installation of fans in a large indoor sports hall. It was found that optimizing the arrangement of fans and the settings for doors and windows can significantly enhance air convection, improve the distribution of airflow, and increase the thermal comfort of athletes. The combination of natural ventilation systems with mechanical fans can further improve air quality and energy efficiency. These findings can provide practical recommendations for the design of sports halls, which are crucial for improving athletes’ performance and comfort, as well as enhancing the experience of spectators and other users. The analysis results indicate that in Model 2, the average wind speed of Scheme 7 is 1.6% higher than that of Scheme 5, 11.5% higher than that of Scheme 6, and 34.3% higher than that of Scheme 8. Therefore, Schemes 7 and 5 are identified as the optimal solutions for Model 2. When comparing the optimal solutions of both models, it was found that the average wind speed of Scheme 7 is 1.6% higher than that of Scheme 5, and 12% higher than that of Scheme 1, making Scheme 7 the overall optimal solution.OPEN ACCESS Received: 17/07/2024 Accepted: 31/10/2024 Published: 07/04/2025

  Abstract
  In this study, numerical simulations were conducted to investigate the changes in air circulation after the installation of fans in a large indoor sports hall. It was found [...]

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• An Application for Pair Sum Modulo Labeling in Cryptography

  P. Amudha, J. Jayapriya

  Rev. int. métodos numér. cálc. diseño ing. (2025). Vol. 41, (1), 8

  
  

  Abstract

   In the dynamic realmof cybersecurity, it is important to create a strong cryptographic technique to protect sensitive data against advanced threats. This paper introduces an innovative encryption and decryp tion technique leveraging graph theory and matrix algebra, especially through the use of pair sum modulo (PSM) labeling of graphs, adjacency matrices, and self-invertible matrices. The PSM labeling for a simple undirected graph G(VG, EG)with |VG| = p and |EG| = q, is an 1-1 map FG:VG → {±1,±2,...,±p}, and there is an induced edge labeling bijective function gG:EG → {0,1,2,...,(q − 1)} such that gG (uv) = [FG(u)+FG(v)](mod q) is distinct for each edge uv. A graph that satisfies PSM labeling is known as a PSM graph. Building on recent developments in graph labeling and matrix applications in cryp tography, our method enhances security. It improves resistance to brute force attacks by utilizing a large key space. Additionally, it leverages the complexity of matrix inversion to make cryptanalysis more difficult. The amalgamation of these mathematical groundworks reinforces the entropy and resistance to bit-flipping, thereby stimulating the ciphertext against statistical and cryptanalytic threats. We utilize the core principles of PSM labeling andalgorithmicencryptionmethods,asdefinedinpriorresearch, to develop an innovative cryptographic algorithm. The sustainability of the proposed method is verified through a thorough evaluation of its encryption efficacy, computational complexity, and a comparative study with existing cryptographic techniques. This work not only contributes to a new approach to the cryptographic domain but also opens avenues for further research into the integration of advanced mathematical structures in encryption algorithms.

  Abstract
   In the dynamic realmof cybersecurity, it is important to create a strong cryptographic technique to protect sensitive data against advanced threats. This paper introduces [...]

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• Research on Master Production Schedule Optimization of Fast-Moving Consumer Goods Companies Based on the APO-NSAGA Algorithm

  F. Ning, Y. Jin, P. Zhang, X. Yang

  Rev. int. métodos numér. cálc. diseño ing. (2025). Vol. 41, (1), 7

  
  

  Abstract

  This study addresses several issues related to the Master Production Schedule (MPS) in companies, such as over-reliance on manual scheduling by planners, failure to consider the overall perspective of the company, lack of consideration for the impact of seasonal demand fluctuations on the MPS, overlooking potential losses due to stockouts and the resulting loss of market share, inability to adjust the MPS in a timely manner to respond to complex and rapidly changing market demands, and the suboptimal outcomes of the manually compiled production plans. To address these problems, an MPS model is established with the goals of optimizing equipment utilization balance, production costs, inventory costs, and delay costs while comprehensively considering the annual product demand. Subsequently, the artificial protozoan optimization nondominated sorting adaptive genetic algorithm (APO-NSAGA) is developed based on the artificial protozoan optimization (APO) and the non-dominated sorting genetic algorithm (NSGA-II). In this algorithm, autotrophic, heterotrophic, and dormancy behaviors are used to enhance the local search capability and guide the algorithm’s evolutionary process. A self-adaptive crossover and mutation operator, which adjusts according to the number of iterations, is designed to allow the algorithm to converge faster in the early stages of operation and better preserve population diversity and high-fitness individuals in the later stages, thus improving algorithm performance. Finally, through simulation examples, an analysis is conducted on the monthly production volume of the company’s three major product categories, as well as the monthly production, available sales, and demand quantities, end-of-month inventory, stock-to-sales ratio, and inventory turnover rate of five typical products. The results demonstrate that the MPS obtained using the proposed model and algorithm achieves comprehensive optimization.OPEN ACCESS Received: 22/07/2024 Accepted: 01/11/2024 Published: 07/04/2025

  Abstract
  This study addresses several issues related to the Master Production Schedule (MPS) in companies, such as over-reliance on manual scheduling by planners, failure to consider [...]

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• Matrix Algorithms Based on Jacobi and Romanovski-Jacobi Polynomials for Solving the FitzHugh-Nagumo Nonlinear Equation

  R. Hafez, S. Boulaaras, H. Khalifa

  Rev. int. métodos numér. cálc. diseño ing. (2025). Vol. 41, (1), 6

  
  

  Abstract

  The present paper develops and makes efficient, a new, state-of-theart numerical technique for solving the FitzHugh-Nagumo Nonlinear Equation (FH-NNE) with initial and boundary conditions, which represents perhaps the simplest mathematical model for discussing biological systems, including nerve signals and cardiac behavior. Which consists of operational matrices and spectral techniques based on Jacobi and Romanovski-Jacobi polynomials. It is ensured that the nonlinear system is modeled so accurately that it can be effectively solved to ensure the best accuracy combined with computational economy. Comparing the results with the respective numerical results, it is seen that the proposed techniques outdo the standard ones as respects accuracy and efficiency of computation.OPEN ACCESS Received: 11/01/2025 Accepted: 25/02/2025 Published: 07/04/2025

  Abstract
  The present paper develops and makes efficient, a new, state-of-theart numerical technique for solving the FitzHugh-Nagumo Nonlinear Equation (FH-NNE) with initial and boundary [...]

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• Boundary Element Analysis of a Semi-Infinite Anisotropic Plane Containing Inclusions/Holes

  Y. Shiah, C. Ko

  Rev. int. métodos numér. cálc. diseño ing. (2025). Vol. 41, (1), 5

  
  

  Abstract

  In this article, the fundamental solutions with Lekhnitskii-like formulations are implemented in the boundary element method (BEM) to calculate the Two-dimensional elastostatic field in a semi-infinite anisotropic plane containing inclusions/holes. In addition to the source point in the semi-infinite plane, four pseudo-sources are superposed to provide traction-free conditions on the plane surface. To avoid mesh modeling at infinity, the fundamental solutions are modified so that the displacements/stresses at the far field automatically vanish. For modeling problems in civil engineering, loading on the plane surface can be specified as part of the boundary condition. When embedded holes are present in the halfplane, loading on the holes can also be applied. Using the sub-region technique, the elastic field in the half-plane containing inclusions can also be investigated. Studies of a few examples indicate that the proposed BEM is a very efficient and versatile methodology to investigate many practical problems, especially in civil engineering.OPEN ACCESS Received: 11/10/2024 Accepted: 10/01/2025 Published: 07/04/2025

  Abstract
  In this article, the fundamental solutions with Lekhnitskii-like formulations are implemented in the boundary element method (BEM) to calculate the Two-dimensional elastostatic [...]

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• HDAug: Optimizing Medical Image Segmentation through Hyperparameter-Driven Brightness and Contrast Augmentation for Deep Learning Models

  Y. Yang, H. Shao, X. Deng, Y. Jiang

  Rev. int. métodos numér. cálc. diseño ing. (2025). Vol. 41, (1), 4

  
  

  Abstract

  Traditional data augmentation methods, which employ static hyperparameters, often lead to model overfitting. To address this limitation, a novel hyperparameter-driven data augmentation approach (HDAug) is introduced in this study. Training images that simulate a plethora of lighting and exposure conditions are synthesized by HDAug through the stochastic sampling of augmentation hyperparameters, within predefined ranges. Additionally, HDAug does not rely on prior knowledge of specific datasets, endowing it with superior generalization capabilities. The Dice coefficient was utilized as the primary evaluation metric. Experimental results demonstrate that HDAug achieves significant performance improvements in two challenging cross-modality medical image segmentation datasets, with average Dice coefficients of 86.77%, 88.08%, and 84.11%, respectively. The superiority of HDAug lies in its ability to substantially enhance model robustness across diverse imaging conditions while circumventing the overfitting issues inherent in conventional methods. Furthermore, HDAug is computationally efficient and is integrated into existing medical image segmentation workflows.OPEN ACCESS Received: 30/08/2024 Accepted: 22/10/2024 Published: 07/04/2025

  Abstract
  Traditional data augmentation methods, which employ static hyperparameters, often lead to model overfitting. To address this limitation, a novel hyperparameter-driven data [...]

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• Approximate Solutions for Fractional Gas Dynamics and Convection-Diffusion Equations via the Temimi-Ansari Method

  A. Almuneef, A. Hagag

  Rev. int. métodos numér. cálc. diseño ing. (2025). Vol. 41, (1), 3

  
  

  Abstract

  In this paper, a new analytical iterative method is used to obtain the fractional analytical solutions of the nonlinear gas dynamics and convectiondiffusion equations. The paper’s novelty appears in its specific application of the Caputo fractional operator to conventional equations while achieving highly accurate solutions. Numerical outcomes for various cases of the equations are represented via tables and graphs. The convergence analysis for the present approach was completed. The methodology is very capable of reducing the size of the analytical steps and is convenient and efficient for solving nonlinear fractional equations. The Temimi-Ansari method’s applicability across different types of fractional differential equations indicates its potential as a powerful tool in solving nonlinear fractional models in diverse scientific and technical fields.OPEN ACCESS Received: 19/07/2024 Accepted: 11/11/2024 Published: 07/04/2025

  Abstract
  In this paper, a new analytical iterative method is used to obtain the fractional analytical solutions of the nonlinear gas dynamics and convectiondiffusion equations. The [...]

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• Improved Modal Parameter Identification of Spillway Radial Gate under Discharge Excitation based on COV-SSI

  Y. Lu, Y. Liu*, Z. Cao, D. Zhang, C. Neng

  Rev. int. métodos numér. cálc. diseño ing. (2025). Vol. 41, (1), 2

  
  

  Abstract

  This paper aims to improve the accuracy of modal parameter identification for Spillway Radial Gate (SRG) under discharge excitation. An Improved Covariance-driven Stochastic Subspace Identification (COVISSI) method, enhanced by Singular Entropy Increment (SEI) and Potential-based Hierarchical Agglomerative (PHA) clustering, is proposed. This method is designed to effectively eliminate false poles in the identification process. The performance of COV-ISSI is compared against the original stochastic subspace identification method, demonstrating its superior capability in accurately identifying modal parameters. Additionally, both the Additional Mass Method (AMM) and Direct Coupling Method (DCM) are employed to model the fluid-structure interaction system of the SRG. The derived vibration frequencies are compared with those obtained from COV-ISSI and an improved peak-picking method. Results show that the DCM closely aligns with COV-ISSI, with a relative error within 3%, while AMM results show significant deviation from the DCM. The proposed COV-ISSI method provides a reliable and automatic approach for identifying the operating frequencies of SRG structures, offering significant improvements over traditional methods.OPEN ACCESS Received: 24/07/2024 Accepted: 27/09/2024 Published: 07/04/2025

  Abstract
  This paper aims to improve the accuracy of modal parameter identification for Spillway Radial Gate (SRG) under discharge excitation. An Improved Covariance-driven Stochastic [...]

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• Study on the Deformation Law of Foundation Pit with Shared Ground Connecting Walls

  Z. XU, X. Shao, J. He, Y. Chen, L. Wang

  Rev. int. métodos numér. cálc. diseño ing. (2025). Vol. 41, (1), 1

  
  

  Abstract

  This study comprehensively investigates the mechanical behavior and deformation patterns of adjacent foundation pits sharing a common ground connecting wall. Utilizing a combination of detailed field measurements and finite element modeling, the study simulates the excavation process to analyze the mutual interactions between two adjacent pits of equal depth. Results indicate that the excavation of a subsequent pit influences both surface settlement and the horizontal displacement of the retaining structure of the first-excavated pit. Specifically, the surface settlement outside the first-excavated pit increased by 0.08% H

  Abstract
  This study comprehensively investigates the mechanical behavior and deformation patterns of adjacent foundation pits sharing a common ground connecting wall. Utilizing a combination [...]

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• A Fractional Semi-Analytical Iterative Method for the Approximate Treatment of Fisher’s Equations_prueba_latex

  J. Sánchez Pinedo, A. Almuneef

  (Select a year).

  
  

  Abstract

  This study presents a novel fractional semi-analytical iterative approach for solving nonlinear fractional Fisher’s equations using the Caputo fractional operator. The primary objective is to provide a method that yields exact solutions to nonlinear fractional equations without requiring assumptions about nonlinear terms. By applying the Temimi-Ansari Method (TAM) with fractional calculus, this approach offers a robust solution to the time-fractional nonlinear Fisher’s equation, a model relevant in fields such as population dynamics, tumor growth, and gene propagation. In this work, tables and graphical illustrations show that the proposed method minimizes computational complexity and delivers significant accuracy across multiple cases of Fisher’s equations. The findings indicate that TAM with fractional order derivatives provides accurate, efficient approximations with reduced computational workload, showcasing the technique’s potential for addressing a wide range of nonlinear fractional differential equations.OPEN ACCESS Received: 19/07/2024 Accepted: 01/11/2024

  Abstract
  This study presents a novel fractional semi-analytical iterative approach for solving nonlinear fractional Fisher’s equations using the Caputo fractional operator. The [...]

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