Mathematical and Computational Applications最新文献_第6页

Bayes Inference of Structural Safety under Extreme Wind Loads Based upon a Peak-Over-Threshold Process of Exceedances 基于峰值-阈值超限过程的极端风荷载下的结构安全贝叶斯推论

Mathematical and Computational Applications Pub Date : 2023-11-30 DOI: 10.3390/mca28060111

E. Chiodo, Fabio De De Angelis, B. Diban, Giovanni Mazzanti

{"title":"Bayes Inference of Structural Safety under Extreme Wind Loads Based upon a Peak-Over-Threshold Process of Exceedances","authors":"E. Chiodo, Fabio De De Angelis, B. Diban, Giovanni Mazzanti","doi":"10.3390/mca28060111","DOIUrl":"https://doi.org/10.3390/mca28060111","url":null,"abstract":"In the present paper, the process of estimating the important statistical properties of extreme wind loads on structures is investigated by considering the effect of large variability. In fact, for the safety design and operating conditions of structures such as the ones characterizing tall buildings, wind towers, and offshore structures, it is of interest to obtain the best possible estimates of extreme wind loads on structures, the recurrence frequency, the return periods, and other stochastic properties, given the available statistical data. In this paper, a Bayes estimation of extreme load values is investigated in the framework of structural safety analysis. The evaluation of extreme values of the wind loads on the structures is performed via a combined employment of a Poisson process model for the peak-over-threshold characterization and an adequate characterization of the parent distribution which generates the base wind load values. In particular, the present investigation is based upon a key parameter for assessing the safety of structures, i.e., a proper safety index referred to a given extreme value of wind speed. The attention is focused upon the estimation process, for which the presented procedure proposes an adequate Bayesian approach based upon prior assumptions regarding (1) the Weibull probability that wind speed is higher than a prefixed threshold value, and (2) the frequency of the Poisson process of gusts. In the last part of the investigation, a large set of numerical simulations is analyzed to evaluate the feasibility and efficiency of the above estimation method and with the objective to analyze and compare the presented approach with the classical Maximum Likelihood method. Moreover, the robustness of the proposed Bayes estimation is also investigated with successful results, both with respect to the assumed parameter prior distributions and with respect to the Weibull distribution of the wind speed values.","PeriodicalId":352525,"journal":{"name":"Mathematical and Computational Applications","volume":"312 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139204195","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Explicit Integrating Factor Runge–Kutta Method for the Extended Fisher–Kolmogorov Equation 扩展费希尔-科尔莫戈罗夫方程的显式积分因子 Runge-Kutta 方法

Mathematical and Computational Applications Pub Date : 2023-11-22 DOI: 10.3390/mca28060110

Yanan Wang, Shuying Zhai

引用次数: 0

Asymptotic Consideration of Rayleigh Waves on a Coated Orthorhombic Elastic Half-Space Reinforced Using an Elastic Winkler Foundation 使用弹性温克勒地基加固的涂覆正交弹性半空间上的瑞利波渐近考量

Mathematical and Computational Applications Pub Date : 2023-11-15 DOI: 10.3390/mca28060109

Ali M. Mubaraki

引用次数: 0

Fractional Hermite–Hadamard-Type Inequalities for Differentiable Preinvex Mappings and Applications to Modified Bessel and q-Digamma Functions 可微前凸映射的分数阶hermite - hadamard型不等式及其在修正Bessel和q-Digamma函数中的应用

Mathematical and Computational Applications Pub Date : 2023-11-09 DOI: 10.3390/mca28060108

Muhammad Tariq, Hijaz Ahmad, Asif Ali Shaikh, Sotiris K. Ntouyas, Evren Hınçal, Sania Qureshi

引用次数: 0

Model-Based Assessment of Elastic Material Parameters in Rheumatic Heart Disease Patients and Healthy Subjects 基于模型的风湿性心脏病患者和健康人弹性材料参数评估

Mathematical and Computational Applications Pub Date : 2023-11-01 DOI: 10.3390/mca28060106

Mary A. Familusi, Sebastian Skatulla, Jagir R. Hussan, Olukayode O. Aremu, Daniel Mutithu, Evelyn N. Lumngwena, Freedom N. Gumedze, Ntobeko A. B. Ntusi

{"title":"Model-Based Assessment of Elastic Material Parameters in Rheumatic Heart Disease Patients and Healthy Subjects","authors":"Mary A. Familusi, Sebastian Skatulla, Jagir R. Hussan, Olukayode O. Aremu, Daniel Mutithu, Evelyn N. Lumngwena, Freedom N. Gumedze, Ntobeko A. B. Ntusi","doi":"10.3390/mca28060106","DOIUrl":"https://doi.org/10.3390/mca28060106","url":null,"abstract":"Non-invasive measurements are important for the development of new treatments for heart failure, which is one of the leading causes of death worldwide. This study aimed to develop realistic subject-specific computational models of human biventricles using clinical data. Three-dimensional finite element models of the human ventricles were created using cardiovascular magnetic resonance images of rheumatic heart disease (RHD) patients and healthy subjects. The material parameter optimization uses inverse modeling based on the finite element method combined with the Levenberg–Marquardt method (LVM) by targeting subject-specific hemodynamics. The study of elastic myocardial parameters between healthy subjects and RHD patients showed an elevated stiffness in diseased hearts. In particular, the anisotropic material behavior of the healthy and diseased cardiac tissue significantly differed from one another. Furthermore, as the LVEF decreased, the stiffness and its orientation-dependent parameters increased. The simulation-derived LV myocardial circumferential and longitudinal stresses were negatively associated with the LVEF. The sensitivity analysis result demonstrated that the observed significant difference between the elastic material parameters of diseased and healthy myocardium was not exclusively attributable to an increased LVEDP in the diseased heart. These results could be applied to future computational studies for developing heart failure treatment.","PeriodicalId":352525,"journal":{"name":"Mathematical and Computational Applications","volume":"49 5","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135221372","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Comparative Study of Metaheuristic Optimization of Convolutional Neural Networks Applied to Face Mask Classification 卷积神经网络元启发式优化在面罩分类中的比较研究

Mathematical and Computational Applications Pub Date : 2023-11-01 DOI: 10.3390/mca28060107

Patricia Melin, Daniela Sánchez, Martha Pulido, Oscar Castillo

{"title":"Comparative Study of Metaheuristic Optimization of Convolutional Neural Networks Applied to Face Mask Classification","authors":"Patricia Melin, Daniela Sánchez, Martha Pulido, Oscar Castillo","doi":"10.3390/mca28060107","DOIUrl":"https://doi.org/10.3390/mca28060107","url":null,"abstract":"The preventive measures taken to curb the spread of COVID-19 have emphasized the importance of wearing face masks to prevent potential infection with serious diseases during daily activities or for medical professionals working in hospitals. Due to the mandatory use of face masks, various methods employing artificial intelligence and deep learning have emerged to detect whether individuals are wearing masks. In this paper, we utilized convolutional neural networks (CNNs) to classify the use of face masks into three categories: no mask, incorrect mask, and proper mask. Establishing the appropriate CNN architecture can be a demanding task. This study compares four swarm intelligent metaheuristics: particle swarm optimization (PSO), grey wolf optimizer (GWO), bat algorithm (BA), and whale optimization algorithm (WOA). The CNN architecture design involves determining the essential hyperparameters of the CNNs. The results indicate the effectiveness of the PSO and BA in achieving an accuracy of 100% when using 10% of the images for testing. Meanwhile, when 90% of the images were used for testing, the results were as follows: PSO 97.15%, WOA 97.14%, BA 97.23%, and GWO 97.18%. These statistically significant differences demonstrate that the BA allows better results than the other metaheuristics analyzed in this study.","PeriodicalId":352525,"journal":{"name":"Mathematical and Computational Applications","volume":"24 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135325415","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Modelization of Low-Cost Maneuvers for an Areostationary Preliminary Mission Design 非静止初始任务设计的低成本机动建模

Mathematical and Computational Applications Pub Date : 2023-10-27 DOI: 10.3390/mca28060105

Marta M. Sánchez-García, Gonzalo Barderas, Pilar Romero

{"title":"Modelization of Low-Cost Maneuvers for an Areostationary Preliminary Mission Design","authors":"Marta M. Sánchez-García, Gonzalo Barderas, Pilar Romero","doi":"10.3390/mca28060105","DOIUrl":"https://doi.org/10.3390/mca28060105","url":null,"abstract":"The aim of this paper is to analyze the determination of interplanetary trajectories from Earth to Mars to evaluate the cost of the required impulse magnitudes for an areostationary orbiter mission design. Such analysis is first conducted by solving the Lambert orbital boundary value problem and studying the launch and arrival conditions for various date combinations. Then, genetic algorithms are applied to investigate the minimum-energy transfer orbit. Afterwards, an iterative procedure is used to determine the heliocentric elliptic transfer orbit that matches at the entry point of Mars’s sphere of influence with an areocentric hyperbolic orbit imposing specific conditions on inclination and periapsis radius. Finally, the maneuvers needed to obtain an areostationary orbit are numerically computed for different objective condition values at the Mars entry point to evaluate an areostationary preliminary mission cost for further study and characterization. Results show that, for the dates of the minimum-energy Earth–Mars transfer trajectory, a low value for the maneuvers to achieve an areostationary orbit is obtained for an arrival hyperbola with the minimum possible inclination and a capture into an elliptical trajectory with a low periapsis radius and an apoapsis at the stationary orbit. For a 2026 mission with a TOF of 304 for the minimum-energy Earth–Mars transfer trajectory, for a capture with a periapsis of 300 km above the Mars surface the value achieved will be 2.083 km/s.","PeriodicalId":352525,"journal":{"name":"Mathematical and Computational Applications","volume":"8 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136318123","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Observer-Based State Estimation for Recurrent Neural Networks: An Output-Predicting and LPV-Based Approach 基于观测器的递归神经网络状态估计:一种基于输出预测和lpv的方法

Mathematical and Computational Applications Pub Date : 2023-10-25 DOI: 10.3390/mca28060104

Wanlin Wang, Jinxiong Chen, Zhenkun Huang

引用次数: 0

Data-Driven Framework for Uncovering Hidden Control Strategies in Evolutionary Analysis 揭示进化分析中隐藏控制策略的数据驱动框架

Mathematical and Computational Applications Pub Date : 2023-10-20 DOI: 10.3390/mca28050103

Nourddine Azzaoui, Tomoko Matsui, Daisuke Murakami

{"title":"Data-Driven Framework for Uncovering Hidden Control Strategies in Evolutionary Analysis","authors":"Nourddine Azzaoui, Tomoko Matsui, Daisuke Murakami","doi":"10.3390/mca28050103","DOIUrl":"https://doi.org/10.3390/mca28050103","url":null,"abstract":"We devised a data-driven framework for uncovering hidden control strategies used by an evolutionary system described by an evolutionary probability distribution. This innovative framework enables deciphering of the concealed mechanisms that contribute to the progression or mitigation of such situations as the spread of COVID-19. Novel algorithms are used to estimate the optimal control in tandem with the parameters for evolution in general dynamical systems, thereby extending the concept of model predictive control. This marks a significant departure from conventional control methods, which require knowledge of the system to manipulate its evolution and of the controller’s strategy or parameters. We use a generalized additive model, supplemented by extensive statistical testing, to identify a set of predictor covariates closely linked to the control. Using real-world COVID-19 data, we delineate the descriptive behaviors of the COVID-19 epidemics in five prefectures in Japan and nine countries. We compare these nine countries and group them on the basis of shared profiles, providing valuable insights into their pandemic responses. Our findings underscore the potential of our framework as a powerful tool for understanding and managing complex evolutionary processes.","PeriodicalId":352525,"journal":{"name":"Mathematical and Computational Applications","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135569356","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Applying Physics-Informed Neural Networks to Solve Navier–Stokes Equations for Laminar Flow around a Particle 应用物理信息神经网络求解粒子周围层流的Navier-Stokes方程

Mathematical and Computational Applications Pub Date : 2023-10-13 DOI: 10.3390/mca28050102

Beichao Hu, Dwayne McDaniel

{"title":"Applying Physics-Informed Neural Networks to Solve Navier–Stokes Equations for Laminar Flow around a Particle","authors":"Beichao Hu, Dwayne McDaniel","doi":"10.3390/mca28050102","DOIUrl":"https://doi.org/10.3390/mca28050102","url":null,"abstract":"In recent years, Physics-Informed Neural Networks (PINNs) have drawn great interest among researchers as a tool to solve computational physics problems. Unlike conventional neural networks, which are black-box models that “blindly” establish a correlation between input and output variables using a large quantity of labeled data, PINNs directly embed physical laws (primarily partial differential equations) within the loss function of neural networks. By minimizing the loss function, this approach allows the output variables to automatically satisfy physical equations without the need for labeled data. The Navier–Stokes equation is one of the most classic governing equations in thermal fluid engineering. This study constructs a PINN to solve the Navier–Stokes equations for a 2D incompressible laminar flow problem. Flows passing around a 2D circular particle are chosen as the benchmark case, and an elliptical particle is also examined to enrich the research. The velocity and pressure fields are predicted by the PINNs, and the results are compared with those derived from Computational Fluid Dynamics (CFD). Additionally, the particle drag force coefficient is calculated to quantify the discrepancy in the results of the PINNs as compared to CFD outcomes. The drag coefficient maintained an error within 10% across all test scenarios.","PeriodicalId":352525,"journal":{"name":"Mathematical and Computational Applications","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135855296","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0