Mathematical Models and Computer Simulations最新文献

{"title":"Phenomenological Models of Three Scenarios of Local SARS-COV-2 Coronavirus Epidemics in New York, Brazil, and Japan","authors":"A. Yu. Perevaryukha","doi":"10.1134/s2070048224700078","DOIUrl":"https://doi.org/10.1134/s2070048224700078","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The COVID-19 pandemic did not end in the summer of 2023 but moved into the stage of a dynamic confrontation between a mutating pathogen and herd immunity (natural and vaccine). Pandemic influenza strains were guaranteed to die out after three waves. SARS-COV-2 is able to maintain variability in its E and S proteins. The diversity of SARS-COV-2 strains increases in bursts (XBB.x in India, XBC in the Philippines). Most strains drop out of distribution, but the remaining ones give rise to new branches such as BA.2.86 Pirola and its descendants of the JN.x series, active in the winter wave of 2024. The evolution is reflected by the pulsation in the number of recorded infections, but the frequency and amplitude of the peaks differ in regions. Regional epidemic scenarios are emerging, and some of them are unusual. It is not only the property of the variability of the antigens of the virus that leads to new repeated outbreaks after the attenuation of the oscillations in the number of infections. Regional epidemic scenarios are being formed, some of them are unusual and interesting for modeling. For a phenomenological model description of scenarios for the emergence of new waves, we propose equations with a delay as a flexible tool for analyzing complex forms of oscillatory dynamics. The equations are supplemented with special threshold damping functions. In the models, it is possible to obtain scenarios of both collapsing and damping oscillations with the possibility of a new outbreak, which describes the effect of a single extreme wave after an increase in the length of active infection chains in New York with a sharp J-shaped peak with oscillatory attenuation that stands out sharply among the morbidity oscillations. The wave scenario in Brazil differs significantly from both the primary outbreak in 2020 and the specific epidemic scenario in Japan in 2022–2023 in the form of a series of eight consecutive short peaks with increasing wave amplitude. Since the coronavirus successfully counteracts the immune system, there is an increase in severe cases of reinfection with COVID-19 in a group that is particularly susceptible. An important factor for slowing down the evolution of the virus is heterogeneity of the population immunity, when activated T-lymphocytes and antibodies produced in the population are able to respond to a wide range of epitopes from different conservative regions of proteins. In the spring of 2024 a new strain JN with significantly reduced affinity for the cell receptor spreads.</p>","PeriodicalId":38050,"journal":{"name":"Mathematical Models and Computer Simulations","volume":"351 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141513502","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}

{"title":"On the Influence of a Dynamic Diffusion Coefficient with the Feibelman Parameter on the Quantum Nonlocal Effect of Hybrid Plasmon Nanoparticles","authors":"Yu. A. Eremin, V. V. Lopushenko","doi":"10.1134/s2070048224700017","DOIUrl":"https://doi.org/10.1134/s2070048224700017","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>In this paper, we consider the problem of polarized light scattering by a hybrid nanoparticle consisting of a dielectric core and plasmonic gold shell. A quantum effect of nonlocality arises in the shell, which is considered in the framework of the semiclassical generalized nonlocal optical response (GNOR) theory. Based on the discrete source method (DSM), a mathematical model of the GNOR theory with a dynamic diffusion coefficient is formulated and implemented. The dynamic diffusion coefficient is determined using the Feibelman quantum surface parameter. In the calculations, the values of the Feibelman parameter are taken from the experimental data available. A comparative analysis of the results of the GNOR theory with constant and dynamic diffusion coefficients is performed. It is established that the results obtained for the dynamic diffusion coefficient and for the traditional semiclassical model with a constant coefficient can differ significantly, especially when studying the behavior of fields near the surface of a hybrid particle in the frequency domain.</p>","PeriodicalId":38050,"journal":{"name":"Mathematical Models and Computer Simulations","volume":"33 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141501619","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}

{"title":"Analysis of a Novel Conformable Fractional Order ASIR Dengue Transmission Model in the Perspective of Bangladesh","authors":"Md. Asaduzzaman, Adem Kilicman, Abdulla -Al-Mamun, Md. Delowar Hossain","doi":"10.1134/s2070048224700157","DOIUrl":"https://doi.org/10.1134/s2070048224700157","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>Dengue fever is an intense feverish virus related disease dispatched with the nibble of <i>Aedes</i> mosquitoes carrying one of the four serotypes, which are symbolized as DEN-1, DEN-2, DEN-3, DEN-4. Almost fifty two percent people of our planet is at risk due to the dengue fever. Particularly, people of the tropical and subtropical countries as like Bangladesh, India, Pakistan, Nepal, Bhutan, Malaysia, etc. are in very risky position due to this fever. In Bangladesh, dengue fever happens nationally and has been endemic for more than two decades. Therefore, for realizing the dynamical conduct of this fever a perfect scientific model of disease transmission plays a noteworthy role and help us to prevent this disease effectively. From this context, in this article a novel six compartmental ASIR dengue transmission model have been established by using conformable fractional order derivatives. In the proposed model, the dynamics of human and mosquito populations have been constructed with six compartments. Here, the analytical stability of equilibria has been shown by disease free and endemic equilibrium points. Furthermore, a sensitivity analysis of the proposed model has been executed to evaluate the comparative rank of the model parameters for dengue transmission. The data of infected human population has been accumulated from different health institutions of Bangladesh which have been used to compute the infection rate of dengue cases in Bangladesh. Finally, a numerical simulation has been constructed for studying the dynamical behavior of dengue transmission with the help of Conformable fractional differential transformation technique.</p>","PeriodicalId":38050,"journal":{"name":"Mathematical Models and Computer Simulations","volume":"185 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141513506","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}

{"title":"Assessment of University Parking Management System: A Simulation-Based Study","authors":"Shahriar Tanvir Alam, Abu Saleh Md. Nakib Uddin, Fahima Akter Azrin","doi":"10.1134/s2070048224700170","DOIUrl":"https://doi.org/10.1134/s2070048224700170","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The university is having difficulty meeting the demand for parking lots to meet the requirements of students. According to data, the number of registered cars at a specific university has been variable over the last 4 years and is mostly growing, whereas the number of parking lots at the university parking area has been stable over these 04 years. Queueing theory has grown in prominence as it provides the numerical foundation for decision-making assessment. Queueing models with multiple servers provide extensive decision-making data, which is critical for evaluating a server’s performance. The purpose of this study is to assess the current situation of a university parking management system by simulating the university parking area in ARENA simulation software. For reducing traffic congestion and confirming the maximum utilization of the university parking lot, this paper formulates multiple server queueing models and assesses their performance. The “Multiple Server Finite Queue Length Infinite Queue Population Model” is most desirable where cars have to wait for less time in the queue (approximately 43.14%) and reduces the queue length by approximately 64.76% in the university parking area. Based on the findings of the queue performance, an ARENA-based simulation has been illustrated to visualize the improved condition of the university parking management system. When the findings from the performance evaluation of the queue model are applied, the simulation results show that the parking area’s capacity is more utilized (from 58.16 to 97.18%) compared to the current situation.</p>","PeriodicalId":38050,"journal":{"name":"Mathematical Models and Computer Simulations","volume":"41 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141513517","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}

{"title":"Fast Algorithm for Solving Some Three-Dimensional Inverse Problems of Magnetometry","authors":"A. S. Leonov, D. V. Lukyanenko, A. G. Yagola","doi":"10.1134/s2070048224700030","DOIUrl":"https://doi.org/10.1134/s2070048224700030","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>Typical three-dimensional inverse problems of magnetic prospecting are considered: determination of the vector density of magnetic dipoles in the studied area of the Earth’s crust from the components of the vector (and/or gradient tensor) of magnetic induction measured on the surface. These problems, being, as a rule, ill-posed, can be solved by standard regularization methods. However, for such a solution on sufficiently detailed grids, significant computing resources (computing clusters, supercomputers, etc.) are required to solve the problem in minutes. The article proposes a new, fast regularizing algorithm for solving such three-dimensional problems, which makes it possible to obtain an approximate solution on a personal computer of average performance in tens of seconds or in a few minutes. In addition, the approach used allows us to calculate an a posteriori error estimate of the found solution in a comparable time, and this makes it possible to evaluate the quality of the solution when interpreting the results. Algorithms for solving the inverse problem and a posteriori error estimation for the solutions found are tested in solving model inverse problems and used in the processing of experimental data.</p>","PeriodicalId":38050,"journal":{"name":"Mathematical Models and Computer Simulations","volume":"97 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141501621","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}

{"title":"Estimation of Parameters in a Traffic Flow Model","authors":"M. A. Pogrebnyak","doi":"10.1134/s207004822470008x","DOIUrl":"https://doi.org/10.1134/s207004822470008x","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>This paper studies the estimation of parameters estimation in a traffic flow model. The model is represented by a system of differential equations with a time delay. The main result of this paper is the calculation of the range of values for the parameters describing the intensity of acceleration and braking, as well as a coefficient that describes how smoothly the pursuing vehicle adjusts its speed to the one in front. The parameters of the model are estimated with analytical calculations and numerical experiments. A special computer program is developed for the numerical experiment.</p>","PeriodicalId":38050,"journal":{"name":"Mathematical Models and Computer Simulations","volume":"30 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141513503","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}

{"title":"Churn Prediction Using Mathematical Programming via a Linear Classification Algorithm","authors":"Mohamed Barhdadi, Badreddine Benyacoub, Mohamed Ouzineb","doi":"10.1134/s2070048224700182","DOIUrl":"https://doi.org/10.1134/s2070048224700182","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The initial idea in developing customer churn prediction was to use statistical analysis of a sample of previous customers to help operators predict which existing customers were likely migrate to other operators. In this paper, a nonstatistical approach to this problem can also be envisaged by formulating the problem as a linear program. The main concept of our proposed algorithm is to hybridize the Jackknife resampling technique with an efficient heuristic based on a variable neighborhood search algorithm to construct a new approach that can present an alternative to black-box machine learning methods. The goal is to find possible solutions (or weights) to minimize error distances and the number of misclassified points. We tested the suggested algorithm with an imbalanced instance and the comparisons show that the proposed model outperforms the most existing machine learning classifiers, both in terms of the solution quality and the execution time. The numerical results indicate that the best solution is achieved in 85% over G-mean of all instances tested. The average gap between our solution and the best solution is still quite small (1.15%).</p>","PeriodicalId":38050,"journal":{"name":"Mathematical Models and Computer Simulations","volume":"7 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141530435","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}

{"title":"Modelling Typhoid Fever Transmission with Treatment Relapse Response: Optimal Control and Cost-Effectiveness Analysis","authors":"Kazeem A. Tijani, Chinwendu E. Madubueze, Reuben I. Gweryina","doi":"10.1134/s2070048224700169","DOIUrl":"https://doi.org/10.1134/s2070048224700169","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>Typhoid fever has become a public health concern, especially in developing countries where sanitation and personal hygiene are not taken seriously, coupled with the non-availability of safe drinking water. Despite the antibiotic treatment, about 2–5% of recovered humans still harbour the typhoid bacteria in their bodies and shed it via their faeces in the population, making it difficult to eradicate the disease. Thus, the effect of limited clinical efficacy of the antibiotics with corresponding relapse response to treatment on infected humans is examined in this paper by formulating a deterministic mathematical model for direct and indirect transmission mode of Typhoid infection. The basic reproduction number is analytically derived and used to implement the global sensitivity analysis of the model’s parameters that employed Latin hypercube Sampling (LHS) with Partial Rank Correlation Coefficient (PRCC). Regarding the sensitivity analysis result, the optimal control and cost-effectiveness analysis are analysed and simulated numerically with four controls, the water, sanitation and hygiene (WASH) practice and awareness campaign control, the sterilisation and disinfection control, the potency of antibiotics control and the screening control. The optimal control analysis applied Pontrygin’s maximum principle to the optimal control problem. The limited efficacy of antibiotics with corresponding relapse response to treatment is shown to influence the spread of typhoid infection in the population. Furthermore, the cost-effectiveness analysis employed Infected Averted Ratio (IAR), Average Cost-effectiveness Ratio (ACER) and Increment Cost-effectiveness Ratio (ICER) techniques to four cases (I–IV) that compared fifteen strategies. The results indicate that the WASH practice and awareness campaign (Strategy 1) is good to implement for single control implementation, while for double control implementation, the WASH practice and awareness campaign and the potency of antibiotics administered to typhoid patients (Strategy 6) is the best to consider. Combining Strategy 6 and screening control is the most cost-effective for triple controls. Furthermore, the overall computation of cost-effectiveness among all the most cost-effective with all the controls combined suggests that Strategy 1 is the most cost-effective strategy to implement for eradicating typhoid infection in the population.</p>","PeriodicalId":38050,"journal":{"name":"Mathematical Models and Computer Simulations","volume":"15 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141513507","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}

{"title":"Modification of a Cross Type Scheme to Eliminate a “Chessboard” Error","authors":"Yu. V. Yanilkin, O. O. Toporova, A. M. Erofeev","doi":"10.1134/s2070048224700042","DOIUrl":"https://doi.org/10.1134/s2070048224700042","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>This paper shows that the cross-type difference schemes used to approximate gas dynamic equations have an error caused by the “chessboard” distribution of thermodynamic quantities. A modification of the two-dimensional (2D) scheme is proposed to eliminate this error. The results of test computations demonstrating the advantages of the new scheme are presented.</p>","PeriodicalId":38050,"journal":{"name":"Mathematical Models and Computer Simulations","volume":"63 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141513500","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}

{"title":"Comparative Analysis of Algebraic Models of Laminar-Turbulent Transition","authors":"A. S. Stabnikov, A. V. Garbaruk, A. A. Matyushenko","doi":"10.1134/s2070048224700091","DOIUrl":"https://doi.org/10.1134/s2070048224700091","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>This paper presents the results of extensive testing of four recently proposed algebraic laminar-turbulent transition (LTT) models, which are significantly more computationally effective than differential models, while being potentially equally accurate. The models chosen for evaluation, namely, SST KD, SST kγ, SST alg-γ, and SA BCM, are implemented in the in-house code NTS and verified by comparing the obtained results with those published by the models’ authors. The experimental database used for the evaluation of the models includes transitional boundary layers at different free-flow turbulence intensities with and without the pressure gradient, four airfoil flows with different LTT scenarios, and a tandem of two airfoils. It is found that at low levels of turbulence, the results of the SA BCM and SST kγ models may depend on the initial approximation, which does not allow them to be recommended for engineering applications. The best results, comparable in accuracy to those of differential models, are obtained using the SST alg-γ model.</p>","PeriodicalId":38050,"journal":{"name":"Mathematical Models and Computer Simulations","volume":"11 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141513505","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}