Avaneesh Singh^*, Manish Kumar Bajpai

CMES-Computer Modeling in Engineering & Sciences, Vol.125, No.3, pp. 991-1031, 2020, DOI:10.32604/cmes.2020.012503

Abstract We have proposed a new mathematical method, the SEIHCRD model, which has an excellent potential to predict the incidence of COVID-19 diseases. Our proposed SEIHCRD model is an extension of the SEIR model. Three-compartments have added death, hospitalized, and critical, which improves the basic understanding of disease spread and results. We have studied COVID-19 cases of six countries, where the impact of this disease in the highest are Brazil, India, Italy, Spain, the United Kingdom, and the United States. After estimating model parameters based on available clinical data, the model will propagate and forecast dynamic evolution. The model calculates the… More >

Avaneesh Singh^*, Saroj Kumar Chandra, Manish Kumar Bajpai

CMES-Computer Modeling in Engineering & Sciences, Vol.125, No.3, pp. 967-990, 2020, DOI:10.32604/cmes.2020.011601

Abstract COVID-19 disease has emerged as one of the life threatening threat to the society. A novel beta coronavirus causes it. It began as unidentified pneumonia of unknown etiology in Wuhan City, Hubei province in China emerged in December 2019. No vaccine has been produced till now. Mathematical models are used to study the impact of different measures used to decrease pandemic. Mathematical models have been designed to estimate the numbers of spreaders in different scenarios in the present manuscript. In the present manuscript, three different mathematical models have been proposed with different scenarios, such as screening, quarantine, and NPIs, to… More >

Olumuyiwa J. Peter¹, Amjad S. Shaikh^2,*, Mohammed O. Ibrahim¹, Kottakkaran Sooppy Nisar³, Dumitru Baleanu^4,5,6, Ilyas Khan⁷, Adesoye I. Abioye¹

CMC-Computers, Materials & Continua, Vol.66, No.2, pp. 1823-1848, 2021, DOI:10.32604/cmc.2020.012314

Abstract We propose a mathematical model of the coronavirus disease 2019 (COVID-19) to investigate the transmission and control mechanism of the disease in the community of Nigeria. Using stability theory of differential equations, the qualitative behavior of model is studied. The pandemic indicator represented by basic reproductive number R₀ is obtained from the largest eigenvalue of the next-generation matrix. Local as well as global asymptotic stability conditions for the disease-free and pandemic equilibrium are obtained which determines the conditions to stabilize the exponential spread of the disease. Further, we examined this model by using Atangana–Baleanu fractional derivative operator and existence criteria… More >

Nawaf N. Hamadneh¹, Waqar A. Khan², Ilyas Khan^{3, *}

CMC-Computers, Materials & Continua, Vol.65, No.2, pp. 1015-1032, 2020, DOI:10.32604/cmc.2020.011476

Abstract One of the most significant considerations in the design of a heat sink is thermal management due to increasing thermal flux and miniature in size. These heat sinks utilize plate or pin fins depending upon the required heat dissipation rate. They are designed to optimize overall performance. Elliptical pin fin heat sinks enhance heat transfer rates and reduce the pumping power. In this study, the Firefly Algorithm is implemented to optimize heat sinks with elliptical pin-fins. The pin-fins are arranged in an inline fashion. The natureinspired metaheuristic algorithm performs powerfully and efficiently in solving numerical global optimization problems. Based on… More >

Liu Yangpeng¹, Ding Jianjun¹, Cao Jingshu², Wang Zhen¹, Jiang Zhuangde¹

Intelligent Automation & Soft Computing, Vol.25, No.4, pp. 767-774, 2019, DOI:10.31209/2019.100000080

Abstract In the conventional measure process of crankshaft, the width of Abbe probe is designed as more than double the eccentricity volume of crank. This even causes the decline of test accuracy due to the probe distortion. This paper proposes a type of servo control mode for measuring crankshaft based on the four-axis motion system. Abbe probe is integrated with Axis motion system. It feeds in a servo way. A mathematical model is developed to ensure the stable contact between probe and workpiece during moving. The results show that, the narrowed Abbe probe will move according to the journal position, thus… More >

Lanting Zhang, Laifu Guo, Qiang Rong^*

Energy Engineering, Vol.117, No.4, pp. 195-207, 2020, DOI:10.32604/EE.2020.010617

Abstract The various ply parameters of composite wind turbine blade have crucial influence, of respectively varying degree, on the static strength and stiffness of the blade, elements closely related to its performance. In this article, the method of the single-parameter sensitivity analysis is presented. A 1.5 MW wind turbine blade is considered as the study object, where the load of the blade is calculated and the respective finite element model is established. According to engineering practice, the investigation range of ply parameters is determined, and the test design scheme of ply parameter for the blade is constructed. The Tsai-Wu failure factor… More >

Muhammad Naveed^{1, *}, Dumitru Baleanu^{2, 3, 4}, Muhammad Rafiq⁵, Ali Raza⁶, Atif Hassan Soori¹, Nauman Ahmed⁷

CMC-Computers, Materials & Continua, Vol.65, No.1, pp. 225-241, 2020, DOI:10.32604/cmc.2020.011534

Abstract Mathematical delay modelling has a significant role in the different disciplines such as behavioural, social, physical, biological engineering, and bio-mathematical sciences. The present work describes mathematical formulation for the transmission mechanism of a novel coronavirus (COVID-19). Due to the unavailability of vaccines for the coronavirus worldwide, delay factors such as social distance, quarantine, travel restrictions, extended holidays, hospitalization, and isolation have contributed to controlling the coronavirus epidemic. We have analysed the reproduction number and its sensitivity to parameters. If, More >

Shihao Fan, Mingliang Chang^*, Shouxi Wang, Qing Quan, Yong Wang, Dan Li

CMES-Computer Modeling in Engineering & Sciences, Vol.124, No.1, pp. 45-59, 2020, DOI:10.32604/cmes.2020.08973

Abstract It is important to determine the insulation thickness in the design of the buried hot oil pipelines. The economic thickness of the insulation layer not only meets the needs of the project but also maximizes the investment and environmental benefits. However, as a significant evaluation, the environmental factors haven’t been considered in the previous study. Considering this factor, the mathematical model of economic insulation thickness of the buried hot oil pipelines is built in this paper, which is solved by the golden section method while considering the costs of investment, operation, environment, the time value of money. The environmental cost… More >

Tongjing Liu^{1, 2, *}, Weixia Liu³, Pengxiang Diwu⁴, Gaixing Hu^{5, 6}, Ting Xu^{1, 7}, Yuqi Li², Zhenjiang You⁸, Runwei Qiao², Jia Wang²

CMES-Computer Modeling in Engineering & Sciences, Vol.123, No.3, pp. 1205-1222, 2020, DOI:10.32604/cmes.2020.08961

Abstract Structure of porous media and fluid distribution in rocks can significantly affect the transport characteristics during the process of microscale tracer flow. To clarify the effect of micro heterogeneity on aqueous tracer transport, this paper demonstrates microscopic experiments at pore level and proposes an improved mathematical model for tracer transport. The visualization results show a faster tracer movement into movable water than it into bound water, and quicker occupancy in flowing pores than in storage pores caused by the difference of tracer velocity. Moreover, the proposed mathematical model includes the effects of bound water and flowing porosity by applying interstitial… More >

Amado Alvarez^1,2, Enrique Rubiños Panta¹, Francisco Gavi Reyes¹, Juan José Alarcón Cabañero², Elizabeth Hernández Acosta³, Carlos Ramírez Ayala¹, Enrique Mejía Saenz¹, Francisco Pedrero Salcedo², Emilio Nicolas Nicolas², Enrique Salazar Sosa⁴

Phyton-International Journal of Experimental Botany, Vol.75, pp. 71-83, 2006, DOI:10.32604/phyton.2006.75.071

Abstract A water quality index as a standardized method to compare the category in an integral way, between locations and through time, of the different water, river and stream storages of the Amajac river basin was developed. In addition, it is possible to predict the degree of contamination and establish planning strategies in the management of the water resources for the river basin in issue. The used methodology was based in the quantitative expression of water quality. Three samplings were made (2005-2006) and Dissolved Oxygen, Coliform in feaces, pH, Oxygen Biochemical Demand, Nitrates, Total Phosphorus, Turbidity and Dissolved Total Solids were… More >