Wejdan Wasel Aljaghthami^*, Mohammad Haseeb Zafar, Afraa Zuhair Attiah

CMC-Computers, Materials & Continua, Vol.70, No.1, pp. 1111-1126, 2022, DOI:10.32604/cmc.2022.019912

Abstract The accelerated development of wireless network technology has resulted in the emergence of Wireless Body Area Network (WBAN), which is a technology commonly used in the medical field. WBAN consists of tiny sensor nodes that interconnect with each other and set in the human body to collect and transmit the patient data to the physician, to monitor the patients remotely. These nodes typically have limited battery energy that led to a shortage of network lifetime. Therefore, energy efficiency is considered one of the most demanding challenges in routing design for WBAN. Many proposed routing mechanisms in WBAN did not cover… More >

Nidal M. Turab¹, Hamza Abu Owida², Jamal I. Al-Nabulsi^2,*, Mwaffaq Abu-Alhaija¹

Computer Systems Science and Engineering, Vol.40, No.1, pp. 167-177, 2022, DOI:10.32604/csse.2022.017973

Abstract The human body contains a near-infinite supply of energy in chemical, thermal, and mechanical forms. However, the majority of implantable and wearable devices are still operated by batteries, whose insufficient capacity and large size limit their lifespan and increase the risk of hazardous material leakage. Such energy can be used to exceed the battery power limits of implantable and wearable devices. Moreover, novel materials and fabrication methods can be used to create various medical therapies and life-enhancing technologies. This review paper focuses on energy-harvesting technologies used in medical and health applications, primarily power collectors from the human body. Current approaches… More >

Sawroop Kaur¹, Aman Singh^1,*, G. Geetha², Mehedi Masud³, Mohammed A. Alzain⁴

CMC-Computers, Materials & Continua, Vol.69, No.3, pp. 2933-2948, 2021, DOI:10.32604/cmc.2021.019030

Abstract Web crawlers have evolved from performing a meagre task of collecting statistics, security testing, web indexing and numerous other examples. The size and dynamism of the web are making crawling an interesting and challenging task. Researchers have tackled various issues and challenges related to web crawling. One such issue is efficiently discovering hidden web data. Web crawler’s inability to work with form-based data, lack of benchmarks and standards for both performance measures and datasets for evaluation of the web crawlers make it still an immature research domain. The applications like vertical portals and data integration require hidden web crawling. Most… More >

Junxiang Jiang^1,2, Shaogang Liu^1,*, Lifeng Feng³

Energy Engineering, Vol.118, No.5, pp. 1287-1303, 2021, DOI:10.32604/EE.2021.015354

Abstract This paper presents a 2DOF nonlinear piezoelectric energy harvester for improving the efficiency of energy harvesting in low frequency range. The device consisted of an L-shaped piezoelectric cantilever with a magnet at the tip of the first beam and two external magnets on the pedestal. The distance between the magnets which generated nonlinear magnetic attraction was adjusted such that the system can exhibit monostable or bistable characteristics. First, the model of this piezoelectric energy harvester was established and the dynamic equation was derived based on the magnetic attractive force. Then, the nonlinear dynamic responses of the system subject to harmonic… More >

Surajo Muhammad^1,*, Jun Jiat Tiang¹, Sew Kin Wong¹, Jamel Nebhen², Amjad Iqbal¹

CMC-Computers, Materials & Continua, Vol.69, No.1, pp. 487-501, 2021, DOI:10.32604/cmc.2021.018292

Abstract This paper proposed the design of a dual-port rectifier with multi-frequency operations. The RF rectifier is achieved using a combination of L-section inductive impedance matching network (IMN) at Port-1 with a multiple stubs impedance transformer at Port-2. The fabricated prototype can harvest RF signal from GSM/900, GSM/1800, UMTS/2100, Wi-Fi/2.45 and LTE/2600 frequency bands at (0.94, 1.80, 2.10, 2.46, and 2.63 GHz), respectively. The rectifier occupies a small portion of a PCB board at 0.20 λg × 0.15 λg. The proposed circuit realized a measured peak RF-to-dc (radio frequency direct current) power conversion efficiency (PCE) of (21%, 22.76%, 25.33%, 21.57%, and… More >

Mohammed Baljon, Shailendra Mishra^*

CMC-Computers, Materials & Continua, Vol.69, No.1, pp. 129-144, 2021, DOI:10.32604/cmc.2021.017509

Abstract Energy harvesting (EH) technology in wireless communication is a promising approach to extend the lifetime of future wireless networks. A cross-layer optimal adaptation policy for a point-to-point energy harvesting (EH) wireless communication system with finite buffer constraints over a Rayleigh fading channel based on a Semi-Markov Decision Process (SMDP) is investigated. Most adaptation strategies in the literature are based on channel-dependent adaptation. However, besides considering the channel, the state of the energy capacitor and the data buffer are also involved when proposing a dynamic modulation policy for EH wireless networks. Unlike the channel-dependent policy, which is a physical layer-based optimization,… More >

Sakorn Inthachai¹, Supasit Paengson², Jindaporn Jamradloedluk^1,*, Tosawat Seetawan^2,*

Journal of Renewable Materials, Vol.9, No.10, pp. 1685-1697, 2021, DOI:10.32604/jrm.2021.015553

Abstract A novel roof tile thermoelectric generator (RT-TEG) was used to harvest electrical energy from a solar heat source. The RT-TEG was fabricated and simulated by flat and curved thermoelectric modules consisting of p-n junctions of p-Sb₂Te₃ and n-Bi₂Te₃, with an Al₂O₃ substrate at the top and bottom for heat absorption and heat rejection. The RT-TEG was installed in a roof tile to act as a generator. The electrical voltage and power values of the curved thermoelectric modules were higher than those of the flat thermoelectric module by 0.44 V and 80 mW, at a temperature difference (ΔT) of 100 K.… More > Graphic Abstract

Watcharaphon Naktong¹, Amnoiy Ruengwaree^1,*, Nuchanart Fhafhiem², Piyaporn Krachodnok³

CMC-Computers, Materials & Continua, Vol.68, No.2, pp. 1731-1750, 2021, DOI:10.32604/cmc.2021.015843

Abstract In this paper, the design of a resonator rectenna, based on metamaterials and capable of harvesting radio-frequency energy at 2.45 GHz to power any low-power devices, is presented. The proposed design uses a simple and inexpensive circuit consisting of a microstrip patch antenna with a mushroom-like electromagnetic band gap (EBG), partially reflective surface (PRS) structure, rectifier circuit, voltage multiplier circuit, and 2.45 GHz Wi-Fi module. The mushroom-like EBG sheet was fabricated on an FR4 substrate surrounding the conventional patch antenna to suppress surface waves so as to enhance the antenna performance. Furthermore, the antenna performance was improved more by utilizing… More >

Surajo Muhammad^1,*, Jun Jiat Tiang¹, Sew Kin Wong¹, Amjad Iqbal¹, Amor Smida², Mohamed Karim Azizi³

CMC-Computers, Materials & Continua, Vol.68, No.1, pp. 167-184, 2021, DOI:10.32604/cmc.2021.016133

Abstract This paper presents a compact multi-band rectifier with an improved impedance matching bandwidth. It uses a combination of п–matching network (MN) at Port-1, with a parallel connection of three cell branch MN at Port-2. The proposed impedance matching network (IMN) is adopted to reduce circuit complexity, to improve circuit performance, and power conversion efficiency (PCE) of the rectifier at low input power. The fabricated rectifier prototype operates at 0.92, 1.82, 2.1, 2.46 and 2.65 GHz covering GSM/900, GSM/1800, UMTS2100, and Wi-Fi/2.45–LTE2600. The size of the compact rectifier on the PCB board is 0.13λ_g × 0.1λ_g. The fabricated rectifier achieved an… More >

Wael Alosaimi^1,*, Hashem Alyami², M. Irfan Uddin³

CMC-Computers, Materials & Continua, Vol.67, No.2, pp. 1665-1677, 2021, DOI:10.32604/cmc.2021.014950

Abstract To meet the food requirements of the seven billion people on Earth, multiple advancements in agriculture and industry have been made. The main threat to food items is from diseases and pests which affect the quality and quantity of food. Different scientific mechanisms have been developed to protect plants and fruits from pests and diseases and to increase the quantity and quality of food. Still these mechanisms require manual efforts and human expertise to diagnose diseases. In the current decade Artificial Intelligence is used to automate different processes, including agricultural processes, such as automatic harvesting. Machine Learning techniques are becoming… More >