M. Sridevi¹, B. Shankar Goud², Ali Hassan^3,4,*, D. Mahendar⁵

Frontiers in Heat and Mass Transfer, Vol.22, No.3, pp. 939-953, 2024, DOI:10.32604/fhmt.2024.050929 - 11 July 2024

Abstract This study intends to evaluate the influence of temperature stratification on an unsteady fluid flow past an accelerated vertical plate in the existence of viscous dissipation. It is assumed that the medium under study is a grey, non-scattered fluid that both fascinates and transmits radiation. The leading equations are discretized using the finite difference method (FDM). Using MATLAB software, the impacts of flow factors on flow fields are revealed with particular examples in graphs and a table. In this regard, FDM results show that the velocity and temperature gradients increase with an increase of Eckert More >

Hailing Yang¹, Suoping Li^1,2,*, Duo Peng²

CMC-Computers, Materials & Continua, Vol.79, No.3, pp. 5273-5294, 2024, DOI:10.32604/cmc.2024.050869 - 20 June 2024

Abstract To address the problems of network congestion and spectrum resources shortage in multi-user large-scale scenarios, this paper proposes a twice random access OFDMA-NOMA-RA protocol combining the advantages of orthogonal frequency division multiple access (OFDMA) and non-orthogonal multiple access (NOMA). The idea of this protocol is that OFMDA is used to divide the entire frequency field into multiple orthogonal resource units (RUs), and NOMA is used on each RU to enable more users to access the channel and improve spectrum efficiency. Based on the protocol designed in this paper, in the case of imperfect successive interference… More >

Aida Haryati Jamadi¹, Nadlene Razali^1,3,*, Sivakumar Dhar Malingam^1,3, Mastura Mohammad Taha^2,3

Journal of Renewable Materials, Vol.11, No.8, pp. 3261-3276, 2023, DOI:10.32604/jrm.2023.028280 - 26 June 2023

Abstract Natural fibre as a reinforcing agent has been widely used in many industrial applications. Nevertheless, several factors need to be considered, such as the size and weight percentage of the fibre used in binding. Using fused deposition modelling (FDM), this factor was investigated by varying the size of natural fibre as the responding variable with a fixed weight percentage of kenaf fibre. The process of modifying the natural fibre in terms of size might increase the dispersion of kenaf fibre in the polymer matrix and increase the adhesion bonding between the fibre and matrix of… More >

Hong Zhu¹, Lisha Gao¹, Lei Wei¹, Guangchang Yang^2,*, Sujie Shao²

CMC-Computers, Materials & Continua, Vol.75, No.3, pp. 5501-5519, 2023, DOI:10.32604/cmc.2023.035759 - 29 April 2023

Abstract As the scale of power networks has expanded, the demand for multi-service transmission has gradually increased. The emergence of WiFi6 has improved the transmission efficiency and resource utilization of wireless networks. However, it still cannot cope with situations such as wireless access point (AP) failure. To solve this problem, this paper combines orthogonal frequency division multiple access (OFDMA) technology and dynamic channel optimization technology to design a fault-tolerant WiFi6 dynamic resource optimization method for achieving high quality wireless services in a wirelessly covered network even when an AP fails. First, under the premise of AP… More >

Omar Abdulghafoor¹, Musbah Shaat², Ibraheem Shayea³, Ahmad Hamood¹, Abdelzahir Abdelmaboud⁴, Ashraf Osman Ibrahim⁵, Fadhil Mukhlif^6,*, Herish Badal¹, Norafida Ithnin⁶, Ali Khadim Lwas⁷

CMC-Computers, Materials & Continua, Vol.75, No.2, pp. 3045-3064, 2023, DOI:10.32604/cmc.2023.033888 - 31 March 2023

Abstract The computational complexity of resource allocation processes, in cognitive radio networks (CRNs), is a major issue to be managed. Furthermore, the complicated solution of the optimal algorithm for handling resource allocation in CRNs makes it unsuitable to adopt in real-world applications where both cognitive users, CRs, and primary users, PUs, exist in the identical geographical area. Hence, this work offers a primarily price-based power algorithm to reduce computational complexity in uplink scenarios while limiting interference to PUs to allowable threshold. Hence, this paper, compared to other frameworks proposed in the literature, proposes a two-step approach… More >

C. Thiruvengadam^1,*, M. Palanivelan²

Intelligent Automation & Soft Computing, Vol.36, No.3, pp. 2803-2818, 2023, DOI:10.32604/iasc.2023.030493 - 15 March 2023

Abstract There are numerous goals in next-generation cellular networks (5G), which is expected to be available soon. They want to increase data rates, reduce end-to-end latencies, and improve end-user service quality. Modern networks need to change because there has been a significant rise in the number of base stations required to meet these needs and put the operators’ low-cost constraints to the test. Because it can withstand interference from other wireless networks, and Adaptive Complex Multicarrier Modulation (ACMM) system is being looked at as a possible choice for the 5th Generation (5G) of wireless networks. Many… More >

Attia Irum¹, Abdul Muiz Fayyaz¹, Sara Ayub², Mudassar Raza³, Majed Alhaisoni⁴, Muhammad Attique Khan⁵, Abdullah Alqahtani⁶, Heebum Kim⁷, Byeong-Gwon Kang^7,*

Computer Systems Science and Engineering, Vol.46, No.1, pp. 1265-1276, 2023, DOI:10.32604/csse.2023.032861 - 20 January 2023

Abstract An effective communication application necessitates the cancellation of Impulsive Noise (IN) from Orthogonal Frequency Division Multiplexing (OFDM), which is widely used for wireless applications due to its higher data rate and greater spectral efficiency. The OFDM system is typically corrupted by Impulsive Noise, which is an unwanted short-duration pulse with random amplitude and duration. Impulsive noise is created by humans and has non-Gaussian characteristics, causing problems in communication systems such as high capacity loss and poor error rate performance. Several techniques have been introduced in the literature to solve this type of problem, but they… More >

Suma Sekhar^1,*, Sakuntala S. Pillai², S. Santhosh Kumar³

Intelligent Automation & Soft Computing, Vol.35, No.3, pp. 3187-3197, 2023, DOI:10.32604/iasc.2023.028702 - 17 August 2022

Abstract Worldwide Interoperability for Microwave Access (WiMAX) trusts Multiple Input Multiple Output-Orthogonal Frequency Division Multiplexing (MIMO-OFDM) combination for the deployment of physical layer functions and for connecting the medium access control to the wireless media. Even though Orthogonal Frequency Division Multiplexing (OFDM) facilitates reliable digital broadband transmission in the fading wireless channels, the presence of synchronization errors in the form of Carrier Frequency Offset (CFO) and Time Offset (TO) adversely affect the performance of OFDM based physical layers. The objective of this work is to improve the accuracy of the frequency and the time offset estimation More >

Heping Hou¹, Yang Yue^1,*, Jian Liu¹, Darun Xi², Shanhui Liu¹

Journal of Renewable Materials, Vol.11, No.1, pp. 273-289, 2023, DOI:10.32604/jrm.2023.021167 - 10 August 2022

Abstract Environmental contamination has been caused by petroleum-based polymeric materials in the melt deposition process. Nowadays biodegradable materials have been widely used in the fused deposition modeling (FDM) industry, such as polylactic acid (PLA). However, internal complex thermal stress and deformations in part caused by an uneven distribution of PLA filament deposition temperatures during FDM, which will seriously affect the geometric accuracy of the printed part. In order to reduce material waste and environmental pollution during the printing process, the accuracy of PLA part can be improved. Herein, numerical simulation was carried out to investigate the… More >

M. Prabhu^1,*, B. Muthu Kumar²

Intelligent Automation & Soft Computing, Vol.35, No.2, pp. 2513-2525, 2023, DOI:10.32604/iasc.2023.027823 - 19 July 2022

Abstract Orthogonal Frequency-Division Multiplexing (OFDM) is the form of a digital system and a way of encoding digital data across multiple frequency components that are used in telecommunication services. Carrier Frequency Offset (CFO) inaccuracy is a major disadvantage of OFDM. This paper proposed a feasible and elegant fuzzy-based resource allocation technique, that overcomes the constraints of the CFO. The suggested Fuzzy linear CFO estimation (FL-CFO) not only estimates the CFO with increased precision but also allocates resources effectively, and achieves maximum utilization of dynamic resources. The suggested FL-CFO error estimation algorithm in OFDM systems employing 1-bit… More >