Said Ali Hassan¹, Khalid Alnowibet², Miral H. Khodeir¹, Prachi Agrawal³, Adel F. Alrasheedi², Ali Wagdy Mohamed^4,5,*

CMC-Computers, Materials & Continua, Vol.69, No.1, pp. 849-871, 2021, DOI:10.32604/cmc.2021.018389

Abstract Commercial airline companies are continuously seeking to implement strategies for minimizing costs of fuel for their flight routes as acquiring jet fuel represents a significant part of operating and managing expenses for airline activities. A nonlinear mixed binary mathematical programming model for the airline fuel task is presented to minimize the total cost of refueling in an entire flight route problem. The model is enhanced to include possible discounts in fuel prices, which are performed by adding dummy variables and some restrictive constraints, or by fitting a suitable distribution function that relates prices to purchased quantities. The obtained fuel plan… More >

Fahad Ahmed Al-Zahrani¹, Imran Khan², Mahdi Zareei^3,*, Asim Zeb⁴, Abdul Waheed^5,6

CMC-Computers, Materials & Continua, Vol.69, No.1, pp. 1201-1214, 2021, DOI:10.32604/cmc.2021.018386

Abstract The next-generation wireless networks are expected to provide higher capacity, system throughput with improved energy efficiency. One of the key technologies, to meet the demand for high-rate transmission, is device-to-device (D2D) communication which allows users who are close to communicating directly instead of transiting through base stations, and D2D communication users to share the cellular user chain under the control of the cellular network. As a new generation of cellular network technology, D2D communication technology has the advantages of improving spectrum resource utilization and improving system throughput and has become one of the key technologies that have been widely concerned… More >

Mohammed Abd-Elnaby^*

CMC-Computers, Materials & Continua, Vol.69, No.1, pp. 521-537, 2021, DOI:10.32604/cmc.2021.018351

Abstract Non-orthogonal multiple access (NOMA) is one of the leading technologies for 5G communication. User pairing (UP) and power allocation (PA) are the key controlling mechanisms for the optimization of the performance of NOMA systems. This paper presents a novel UP and PA (UPPA) technique for capacity and fairness maximization in NOMA called (CFM-UPPA). The impact of the power allocation coefficient and the ratio between the channel gains of the paired users on the sum-rate capacity and the fairness in NOMA is firstly investigated. Then, based on this investigation, the PA and UP algorithms of the CFM-UPPA technique are proposed. The… More >

Dah-Jing Jwo^*, Jia-Chyi Wu, Kuan-Lin Ho

CMC-Computers, Materials & Continua, Vol.69, No.1, pp. 555-574, 2021, DOI:10.32604/cmc.2021.018320

Abstract This paper investigates performance improvement via the incorporation of the support vector machine (SVM) into the vector tracking loop (VTL) for the Global Positioning System (GPS) in limited satellite visibility. Unlike the traditional scalar tracking loop (STL), the tracking and navigation modules in the VTL are not independent anymore since the user’s position can be determined by using the information from other satellites and can be predicted on the basis of the states of the user. The method proposed in this paper makes use of the SVM to bridge the GPS signal and prevent the error growth due to signal… 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 >

Masoud Muhammed Hassan¹, Adel Sabry Eesa^1,*, Ahmed Jameel Mohammed², Wahab Kh. Arabo¹

CMC-Computers, Materials & Continua, Vol.69, No.1, pp. 451-469, 2021, DOI:10.32604/cmc.2021.018280

Abstract Learning from imbalanced data is one of the greatest challenging problems in binary classification, and this problem has gained more importance in recent years. When the class distribution is imbalanced, classical machine learning algorithms tend to move strongly towards the majority class and disregard the minority. Therefore, the accuracy may be high, but the model cannot recognize data instances in the minority class to classify them, leading to many misclassifications. Different methods have been proposed in the literature to handle the imbalance problem, but most are complicated and tend to simulate unnecessary noise. In this paper, we propose a simple… More >

Mahmood ul Hassan^1,*, Shahzad Ali², Khalid Mahmood³, Muhammad Kashif Saeed⁴, Amin Al-Awady¹, Kamran Javed⁵, Ansar Munir Shah⁶

CMC-Computers, Materials & Continua, Vol.69, No.1, pp. 1003-1019, 2021, DOI:10.32604/cmc.2021.018264

Abstract Node failure in Wireless Sensor Networks (WSNs) is a fundamental problem because WSNs operate in hostile environments. The failure of nodes leads to network partitioning that may compromise the basic operation of the sensor network. To deal with such situations, a rapid recovery mechanism is required for restoring inter-node connectivity. Due to the immense importance and need for a recovery mechanism, several different approaches are proposed in the literature. However, the proposed approaches have shortcomings because they do not focus on energy-efficient operation and coverage-aware mechanisms while performing connectivity restoration. Moreover, most of these approaches rely on the excessive mobility… More >

Shahzaib Anwar¹, Sardar Muhammad Gulfam^1,*, Bilal Muhammad², Syed Junaid Nawaz¹, Khursheed Aurangzeb³, Mohammad Kaleem¹

CMC-Computers, Materials & Continua, Vol.69, No.1, pp. 1021-1037, 2021, DOI:10.32604/cmc.2021.018248

Abstract High electron mobility transistor (HEMT) based on gallium nitride (GaN) is one of the most promising candidates for the future generation of high frequencies and high-power electronic applications. This research work aims at designing and characterization of enhancement-mode or normally-off GaN HEMT. The impact of variations in gate length, mole concentration, barrier variations and other important design parameters on the performance of normally-off GaN HEMT is thoroughly investigated. An increase in the gate length causes a decrease in the drain current and transconductance, while an increase in drain current and transconductance can be achieved by increasing the concentration of aluminium… More >

Samer Alabed¹, Ibrahim Mahariq^1,*, Mohammad Salman¹, Mustafa Kuzuoglu²

CMC-Computers, Materials & Continua, Vol.69, No.1, pp. 575-588, 2021, DOI:10.32604/cmc.2021.018245

Abstract In this article, a low-cost electromagnetic structure emulating photonic nanojets is utilized to improve the efficiency of wireless relay networks. The spectral element method, due to its high accuracy, is used to verify the efficiency of the proposed structure by solving the associate field distribution. The application of optimal single-relay selection method shows that full diversity gain with low complexity can be achieved. In this paper, the proposed technique using smart relays combines the aforementioned two methods to attain the benefits of both methods by achieving the highest coding and diversity gain and enhances the overall network performance in terms… More >

Sidra Naseem¹, Kashif Javed¹, Muhammad Jawad Khan¹, Saddaf Rubab², Muhammad Attique Khan³, Yunyoung Nam^4,*

CMC-Computers, Materials & Continua, Vol.69, No.1, pp. 471-486, 2021, DOI:10.32604/cmc.2021.018239

Abstract Electroencephalography is a common clinical procedure to record brain signals generated by human activity. EEGs are useful in Brain controlled interfaces and other intelligent Neuroscience applications, but manual analysis of these brainwaves is complicated and time-consuming even for the experts of neuroscience. Various EEG analysis and classification techniques have been proposed to address this problem however, the conventional classification methods require identification and learning of specific EEG characteristics beforehand. Deep learning models can learn features from data without having in depth knowledge of data and prior feature identification. One of the great implementations of deep learning is Convolutional Neural Network… More >