Nauman Ahmed^1,2, Umbreen Fatima¹, Shahzaib Iqbal¹, Ali Raza³, Muhammad Rafiq^4,*, Muhammad Aziz-ur-Rehman², Shehla Saeed¹, Ilyas Khan⁵, Kottakkaran Sooppy Nisar⁶

CMC-Computers, Materials & Continua, Vol.68, No.1, pp. 201-212, 2021, DOI:10.32604/cmc.2021.014171

Abstract The present work is related to the numerical investigation of the spatio-temporal susceptible-latent-breaking out-recovered (SLBR) epidemic model. It describes the computer virus dynamics with vertical transmission via the internet. In these types of dynamics models, the absolute values of the state variables are the fundamental requirement that must be fulfilled by the numerical design. By taking into account this key property, the positivity preserving algorithm is designed to solve the underlying SLBR system. Since, the state variables associated with the phenomenon, represent the computer nodes, so they must take in absolute. Moreover, the continuous system (SLBR) acquires two steady states… More >

Amal S. Hassan¹, Ehab M. Almetwally^2,*, Gamal M. Ibrahim³

CMC-Computers, Materials & Continua, Vol.68, No.1, pp. 337-358, 2021, DOI:10.32604/cmc.2021.013971

Abstract In this paper, an attempt is made to discover the distribution of COVID-19 spread in different countries such as; Saudi Arabia, Italy, Argentina and Angola by specifying an optimal statistical distribution for analyzing the mortality rate of COVID-19. A new generalization of the recently inverted Topp Leone distribution, called Kumaraswamy inverted Topp–Leone distribution, is proposed by combining the Kumaraswamy-G family and the inverted Topp–Leone distribution. We initially provide a linear representation of its density function. We give some of its structure properties, such as quantile function, median, moments, incomplete moments, Lorenz and Bonferroni curves, entropies measures and stress-strength reliability. Then,… More >

Belal Al-Khateeb^1,*, Kawther Ahmed², Maha Mahmood¹, Dac-Nhuong Le^3,4

CMC-Computers, Materials & Continua, Vol.68, No.1, pp. 643-654, 2021, DOI:10.32604/cmc.2021.013648

Abstract This paper presents a novel metaheuristic algorithm called Rock Hyraxes Swarm Optimization (RHSO) inspired by the behavior of rock hyraxes swarms in nature. The RHSO algorithm mimics the collective behavior of Rock Hyraxes to find their eating and their special way of looking at this food. Rock hyraxes live in colonies or groups where a dominant male watch over the colony carefully to ensure their safety leads the group. Forty-eight (22 unimodal and 26 multimodal) test functions commonly used in the optimization area are used as a testing benchmark for the RHSO algorithm. A comparative efficiency analysis also checks RHSO… More >

Xiaoli Qiang¹, Muhammad Aamir^2,*, Muhammad Naeem², Shaukat Ali³, Adnan Aslam⁴, Zehui Shao¹

CMC-Computers, Materials & Continua, Vol.68, No.1, pp. 841-856, 2021, DOI:10.32604/cmc.2021.012540

Abstract COVID-19 has caused severe health complications and produced a substantial adverse economic impact around the world. Forecasting the trend of COVID-19 infections could help in executing policies to effectively reduce the number of new cases. In this study, we apply the decomposition and ensemble model to forecast COVID-19 confirmed cases, deaths, and recoveries in Pakistan for the upcoming month until the end of July. For the decomposition of data, the Ensemble Empirical Mode Decomposition (EEMD) technique is applied. EEMD decomposes the data into small components, called Intrinsic Mode Functions (IMFs). For individual IMFs modelling, we use the Autoregressive Integrated Moving… More >

Shankarnarayanan Nalini^1,*, Nagappan Krishnaraj², Thangaiyan Jayasankar³, Kalimuthu Vinothkumar⁴, Antony Sagai Francis Britto⁵, Kamalraj Subramaniam⁶, Chokkalingam Bharatiraja⁷

CMC-Computers, Materials & Continua, Vol.68, No.1, pp. 1117-1128, 2021, DOI:10.32604/cmc.2021.012431

Abstract Precision Agriculture is a concept of farm management which makes use of IoT and networking concepts to improve the crop. Plant diseases are one of the underlying causes in the decrease in the number of quantity and quality of the farming crops. Recognition of diseases from the plant images is an active research topic which makes use of machine learning (ML) approaches. A novel deep neural network (DNN) classification model is proposed for the identification of paddy leaf disease using plant image data. Classification errors were minimized by optimizing weights and biases in the DNN model using a crow search… More >

Yottha Srithep^1,*, Onpreeya Veang-in¹, Dutchanee Pholharn², Lih-Sheng Turng³, John Morris⁴

Journal of Renewable Materials, Vol.9, No.7, pp. 1267-1281, 2021, DOI:10.32604/jrm.2021.015604

Abstract A low-molecular-weight polylactide-poly(butylene succinate) (PLA-PBS) copolymer was synthesized and incorporated into polylactide (PLA) as a novel toughening agent by solvent casting. The copolymer had the same chemical structure and function as PLA and it was used as a plasticizer to PLA. The copolymer was blended with PLA at a weight ratio from 2 to 10 wt%. Phase separation between PLA and PLA-PBS was not observed from their scanning electron microscopy (SEM) images and the crystal structure of PLA almost remained unchanged based on the X-ray diffraction (XRD) measurement. The melt flow index (MFI) of the blends was higher as the… More >

Jiekun Zhu, Hongtao Kao^*

Journal of Renewable Materials, Vol.9, No.7, pp. 1329-1343, 2021, DOI:10.32604/jrm.2021.015079

Abstract Based on the theory of computational fluid dynamics (CFD), pulverized coal combustion alone, and the co-combustion of pulverized coal and refuse-derived fuel (RDF) in a Trinal-sprayed calciner (TTF) precalciner were simulated. The results revealed that when coal was used as a single fuel, the velocity field in the precalciner had good symmetry, and formed three spray effects and multiple recirculation zones. The main combustion zone was distributed in the lower tertiary air and pulverized coal area, and the highest temperature reached up to 1,500 K. According to the simulation results, the predicted decomposing rate of raw meal was 90.12%, which… More >

Syed Waheedullah Ghori^1,*, G. Srinivasa Rao²

Journal of Renewable Materials, Vol.9, No.7, pp. 1283-1292, 2021, DOI:10.32604/jrm.2021.014987

Abstract Date palm fiber (DPF) and kenaf fiber were reinforced in epoxy having various fiber loading 40%, 50%, and 60% by weight. These hybrid samples were manufactured by hot press technique and then characterized for tensile, impact, and morphological behavior to evaluate the ratio of fibers in the hybrid composites; the addition of kenaf improved the tensile properties, Scanning Electron Microscopy (SEM) revealed the interfacial bonding of fiber/matrix, and dispersion and void content in composites. Impact test studies reflected the effect of natural fiber with epoxy, level of stress transfer from matrix to reinforced material, and reinforced material’s role in absorbing… More > Graphic Abstract

Xiaohua Gu, Hongxiang Luo^*, Shiwei Lv, Peng Chen

Journal of Renewable Materials, Vol.9, No.7, pp. 1253-1266, 2021, DOI:10.32604/jrm.2021.014876

Abstract Dramatically increasing waste polyurethane rigid foam (WPRF) draws the attention of the world. A mixture of ethylene glycol (EG) and diethylene glycol (DEG) is used as glycolysis agents. WPRF was subjected to alcoholysis using different catalysts which are titanium ethylene glycol and potassium hydroxide to obtain recycled polyol, respectively. The effect of a different catalyst on the viscosity and hydroxyl value of recycled polyol is discussed. The regenerated polyurethane (RPU) is performed using the recycled polyol. Infrared spectrum, compressive strength, apparent density, water absorption, scanning electron microscope, and thermogravimetric analysis are carried out to investigate the effect of WPRF degradation… More >

Chakib Mokhtari¹, Fouad Malek¹, Sami Halila², Mohamed Naceur Belgacem^3,*, Ramzi Khiari^3,4,5,*

Journal of Renewable Materials, Vol.9, No.7, pp. 1213-1223, 2021, DOI:10.32604/jrm.2021.015475

Abstract Bio-based polyurethanes (PUs) have been occurred a large attention nowadays. It was found to be an alternative to the petrochemical based materials to the fact of their weak environmental influence, availability, good price and biodegradability. In addition, the nature shows several bio-derived compounds as raw materials for the synthesis of polyols, including the vegetable oils, polyphenol, terpene, and other bio-renewable sources. With the aim to develop a new family of biobased polyurethanes (PUs) via vegetable oils, the elaboration of new Jojoba-based PUs was performed by catalyst-free polycondensation reaction of a synthesized Jojoba diol with various diisocyanates such us toluene diisocyanate… More > Graphic Abstract