Computational and Mathematical Methods最新文献_第4页

On the Use of Commercial Finite Element Packages for a Dimensionless Solution to a Class of Problems 一类问题的无量纲解的商用有限元包的应用

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Computational and Mathematical Methods Pub Date : 2023-05-12 DOI: 10.1155/2023/4839057

S. Pashah

{"title":"On the Use of Commercial Finite Element Packages for a Dimensionless Solution to a Class of Problems","authors":"S. Pashah","doi":"10.1155/2023/4839057","DOIUrl":"10.1155/2023/4839057","url":null,"abstract":"<div>\u0000 Physical laws provide a mathematical description of a physical phenomenon. The mathematical description is generally in the form of differential equations with appropriate initial and boundary conditions, called initial boundary value problems. The dimensionless form of an initial boundary value problem is the first step for the solution to a class of problems. The approach is generally applied for closed-form (or analytical) solutions, whereas practical engineering problems can only be solved numerically. Commercial finite element packages are commonly used for the numerical solution of engineering problems with complexities caused by geometry, loading, and material properties. A numerical solution does not produce a formula; therefore, a completely new solution must be obtained even for minor changes in the data set. A single-dimensionless finite element analysis would solve a class of problems. Literature shows that user-developed finite element codes, not accessible for general use, are generally used for dimensionless finite element solutions. The availability of dimensionless analysis in a commercial finite element package would be very convenient. Commercial packages do not have built-in dimensionless formulations. However, all mainstream packages allow user-implemented formulation through different coding requirements. At least one researcher has used a commercial package for dimensionless analyses without coding. The work presents a guide on alternate implementation methods of dimensionless formulations in commercial packages. A sample case demonstrates the stepwise implementation of a dimensionless formulation without writing a customized finite element code.\u0000 </div>","PeriodicalId":100308,"journal":{"name":"Computational and Mathematical Methods","volume":"2023 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1155/2023/4839057","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72507517","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Hamiltonicity in Directed Toeplitz Graphs with s1 = 1 and s3 = 4 s1 = 1和s3 = 4的有向Toeplitz图的哈密性

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Computational and Mathematical Methods Pub Date : 2023-04-17 DOI: 10.1155/2023/3676487

Shabnam Malik

引用次数: 0

Mathematical Modeling of COVID-19 with Periodic Transmission: The Case of South Africa 周期性传播COVID-19的数学模型：以南非为例

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Computational and Mathematical Methods Pub Date : 2023-02-15 DOI: 10.1155/2023/9326843

Belthasara Assan, Farai Nyabadza

{"title":"Mathematical Modeling of COVID-19 with Periodic Transmission: The Case of South Africa","authors":"Belthasara Assan, Farai Nyabadza","doi":"10.1155/2023/9326843","DOIUrl":"10.1155/2023/9326843","url":null,"abstract":"<div>\u0000 The data on SARS-CoV-2 (COVID-19) in South Africa show seasonal transmission patterns to date, with the peaks having occurred in winter and summer since the outbreaks began. The transmission dynamics have mainly been driven by variations in environmental factors and virus evolution, and the two are at the center of driving the different waves of the disease. It is thus important to understand the role of seasonality in the transmission dynamics of COVID-19. In this paper, a compartmental model with a time-dependent transmission rate is formulated and the stabilities of the steady states analyzed. We note that if R0 < 1, the disease-free equilibrium is globally asymptotically stable, and the disease completely dies out; and when R0 > 1, the system admits a positive periodic solution, and the disease is uniformly or periodically persistent. The model is fitted to data on new cases in South Africa for the first four waves. The model results indicate the need to consider seasonality in the transmission dynamics of COVID-19 and its importance in modeling fluctuations in the data for new cases. The potential impact of seasonality in the transmission patterns of COVID-19 and the public health implications is discussed.\u0000 </div>","PeriodicalId":100308,"journal":{"name":"Computational and Mathematical Methods","volume":"2023 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1155/2023/9326843","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74227046","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Modeling and Optimal Control Analysis for Malaria Transmission with Role of Climate Variability 考虑气候变率的疟疾传播建模与最优控制分析

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Computational and Mathematical Methods Pub Date : 2022-12-02 DOI: 10.1155/2022/9667396

Temesgen Duressa Keno, Lemessa Bedjisa Dano, Oluwole Daniel Makinde

{"title":"Modeling and Optimal Control Analysis for Malaria Transmission with Role of Climate Variability","authors":"Temesgen Duressa Keno, Lemessa Bedjisa Dano, Oluwole Daniel Makinde","doi":"10.1155/2022/9667396","DOIUrl":"10.1155/2022/9667396","url":null,"abstract":"<div>\u0000 In this paper, we present a nonlinear deterministic mathematical model for malaria transmission dynamics incorporating climatic variability as a factor. First, we showed the limited region and nonnegativity of the solution, which demonstrate that the model is biologically relevant and mathematically well-posed. Furthermore, the fundamental reproduction number was determined using the next-generation matrix approach, and the sensitivity of model parameters was investigated to determine the most affecting parameter. The Jacobian matrix and the Lyapunov function are used to illustrate the local and global stability of the equilibrium locations. If the fundamental reproduction number is smaller than one, a disease-free equilibrium point is both locally and globally asymptotically stable, but endemic equilibrium occurs otherwise. The model exhibits forward and backward bifurcation. Moreover, we applied the optimal control theory to describe the optimal control model that incorporates three controls, namely, using treated bed net, treatment of infected with antimalaria drugs, and indoor residual spraying strategy. The Pontryagin’s maximum principle is introduced to obtain the necessary condition for the optimal control problem. Finally, the numerical simulation of optimality system and cost-effectiveness analysis reveals that the combination of treated bed net and treatment is the most optimal and least-cost strategy to minimize the malaria.\u0000 </div>","PeriodicalId":100308,"journal":{"name":"Computational and Mathematical Methods","volume":"2022 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2022-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1155/2022/9667396","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82514313","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Harmonic Mixture Weibull-G Family of Distributions: Properties, Regression and Applications to Medical Data 调和混合Weibull-G族分布：性质、回归及其在医疗数据中的应用

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Computational and Mathematical Methods Pub Date : 2022-11-28 DOI: 10.1155/2022/2836545

Ernest Zamanah, Suleman Nasiru, Albert Luguterah

引用次数: 0

Convergence Analysis of a Modified Forward-Backward Splitting Algorithm for Minimization and Application to Image Recovery 一种改进的前向后分割算法的收敛性分析及其在图像恢复中的应用

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Computational and Mathematical Methods Pub Date : 2022-10-06 DOI: 10.1155/2022/3455998

Kunrada Kankam, Watcharaporn Cholamjiak, Prasit Cholamjiak

引用次数: 0

An LSTM-Autoencoder Architecture for Anomaly Detection Applied on Compressors Audio Data lstm自编码器结构在压缩音频数据异常检测中的应用

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Computational and Mathematical Methods Pub Date : 2022-09-29 DOI: 10.1155/2022/3622426

Pooyan Mobtahej, Xulong Zhang, Maryam Hamidi, Jing Zhang

{"title":"An LSTM-Autoencoder Architecture for Anomaly Detection Applied on Compressors Audio Data","authors":"Pooyan Mobtahej, Xulong Zhang, Maryam Hamidi, Jing Zhang","doi":"10.1155/2022/3622426","DOIUrl":"10.1155/2022/3622426","url":null,"abstract":"<div>\u0000 The compressors used in today’s natural gas production industry have an essential role in maintaining the production line operational. Each of the compressors’ components has routine maintenance tasks to avoid sudden failures. Hence, the significant advantages and benefits of performing preventative maintenance tasks in time are decreasing equipment downtime, saving additional costs, and improving the safety and reliability of the whole system. In this paper, anomaly classification and detection methods based on a neural network hybrid model named Long Short-Term Memory (LSTM)-Autoencoder (AE) is proposed to detect anomalies in sequence pattern of audio data, collected by multiple sound sensors deployed at different components of each compressor system for predictive maintenance. In research methodology, this paper has conducted experiments that employed different RNN architectures such as GRU, LSTM, Stacked LSTM, and Stacked GRU with various functions to create a baseline for model evaluation. Each architecture used audio signals dataset received from the compressor system for experiments to consider each neural network model’s performance. According to performance results, an optimal model for anomaly detection with the best performance scores has been proposed in this research. Experiments combined one-dimensional raw audio signal features using SC and Mel spectrogram features were fed to deep learning models to evaluate performance. Hence, such hybrid methods can effectively detect normal and anomaly audio signals collected from a compressor system, increasing the compressor system’s reliability and the sustainability of the gas production line. The combination of multiple-resource features in the proposed hybrid model showed a 100% score in all four-evaluation metrics such as accuracy, precision, recall, and F1 in LSTM-based autoencoder in both test and train results.\u0000 </div>","PeriodicalId":100308,"journal":{"name":"Computational and Mathematical Methods","volume":"2022 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2022-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1155/2022/3622426","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72472834","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Mathematical Model Formulation and Analysis for COVID-19 Transmission with Virus Transfer Media and Quarantine on Arrival 新型冠状病毒传播媒介与入境检疫的数学模型建立与分析

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Computational and Mathematical Methods Pub Date : 2022-09-26 DOI: 10.1155/2022/2955885

Tesfaye Tadesse Ega, Rigobert Charles Ngeleja

{"title":"Mathematical Model Formulation and Analysis for COVID-19 Transmission with Virus Transfer Media and Quarantine on Arrival","authors":"Tesfaye Tadesse Ega, Rigobert Charles Ngeleja","doi":"10.1155/2022/2955885","DOIUrl":"10.1155/2022/2955885","url":null,"abstract":"<div>\u0000 An outbreak of severe acute respiratory syndrome (COVID-19) killed 287,355 with 4, 257,578 cases worldwide as of May 12, 2020. In this paper, we propose an SEQIsIaRM deterministic mathematical model which contains compartments for both human-to-human transmission and transmission through contaminated surfaces. Without intervention, the role of symptomatic and asymptomatic cases in humans is found to be very high in the transmission of the virus. Sensitive parameters which are associated with increased transmission of the COVID-19 virus were identified. According to the sensitivity results, the most sensitive parameters were disease-induced death rates of symptomatic and asymptomatic infectious people (σ), the rate of removal of virus from surfaces and environment (ν), and the rate of infection by asymptomatic infectious people (λ2) and symptomatic infectious people (λ1). The numerical results of our model confirm the sensitivity results that there are more new incidences of asymptomatic cases than symptomatic cases, which escalates the transmission of the virus in the community. Combined interventions like increasing both the rate of removal of viruses from surfaces and environment and decreasing the rate of infection in asymptomatic cases can play a significant role in reducing the average number of secondary infection (R0) to less than unity, causing COVID-19 to die out.\u0000 </div>","PeriodicalId":100308,"journal":{"name":"Computational and Mathematical Methods","volume":"2022 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2022-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1155/2022/2955885","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79660179","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A Multidimensional Game Theory–Based Group Decision Model for Predictive Analytics 基于多维博弈论的预测分析群体决策模型

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Computational and Mathematical Methods Pub Date : 2022-09-16 DOI: 10.1155/2022/5089021

Mirhossein Mousavi Karimi, Shahram Rahimi, Mohammad Nagahisarchoghaei, Chaomin Luo

引用次数: 0

Approximate Hermite Interpolations for Compactly Supported Linear Canonical Transforms 紧支持线性正则变换的近似Hermite插值

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Computational and Mathematical Methods Pub Date : 2022-09-09 DOI: 10.1155/2022/5243466

I. A. Al-Abdi

引用次数: 0