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Electronics
Volume 10
Issue 12
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Electronics, Volume 10, Issue 12 (June-2 2021) – 137 articles

Cover Story (view full-size image): The miniaturized high-gain antenna is required in portable, ultra-wideband radar systems. However, the miniaturization, ultra-wideband and high gain often restrict each other in the antenna design. In this paper, a dual-polarized, double-slot, antipodal tapered slot antenna with a double-layer, dual-loop structure and novel slot edges is presented. The proposed magnetic dual-loop structure has the capacity to reduce the low cut-off frequency of the double-slot tapered slot antenna by weakening the resonance and coupling. The dual-polarized antenna combines two orthogonal elements in a cross configuration without galvanic contact or influence on performance. The results show that the impedance bandwidth of the proposed antenna is 0.6~4 GHz, and the maximum gain is 11 dBi. The isolation between the two antenna ports is better than 32 dB. View this paper
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19 pages, 996 KiB  
Article
Algorithms for Finding Vulnerabilities and Deploying Additional Sensors in a Region with Obstacles
by Kibeom Kim and Sunggu Lee
Electronics 2021, 10(12), 1504; https://doi.org/10.3390/electronics10121504 - 21 Jun 2021
Cited by 4 | Viewed by 1922
Abstract
Consider a two-dimensional rectangular region guarded by a set of sensors, which may be smart networked surveillance cameras or simpler sensor devices. In order to evaluate the level of security provided by these sensors, it is useful to find and evaluate the path [...] Read more.
Consider a two-dimensional rectangular region guarded by a set of sensors, which may be smart networked surveillance cameras or simpler sensor devices. In order to evaluate the level of security provided by these sensors, it is useful to find and evaluate the path with the lowest level of exposure to the sensors. Then, if desired, additional sensors can be placed at strategic locations to increase the level of security provided. General forms of these two problems are presented in this paper. Next, the minimum exposure path is found by first using the sensing limits of the sensors to compute an approximate “feasible area” of interest, and then using a grid within this feasible area to search for the minimum exposure path in a systematic manner. Two algorithms are presented for the minimum exposure path problem, and an additional subsequently executed algorithm is proposed for sensor deployment. The proposed algorithms are shown to require significantly lower computational complexity than previous methods, with the fastest proposed algorithm requiring O(n2.5) time, as compared to O(mn3) for a traditional grid-based search method, where n is the number of sensors, m is the number of obstacles, and certain assumptions are made on the parameter values. Full article
(This article belongs to the Special Issue 10th Anniversary of Electronics: Recent Advances in Computer Science & Engineering)
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11 pages, 5113 KiB  
Article
Numerical Analysis of the High Pressure MOVPE Upside-Down Reactor for GaN Growth
by Przemyslaw Niedzielski, Ewa Raj, Zbigniew Lisik, Jerzy Plesiewicz, Ewa Grzanka, Robert Czernecki and Mike Leszczynski
Electronics 2021, 10(12), 1503; https://doi.org/10.3390/electronics10121503 - 21 Jun 2021
Cited by 4 | Viewed by 1869
Abstract
The present paper focuses on the high-pressure metal-organic vapor phase epitaxy (MOVPE) upside-down vertical reactor (where the inlet of cold gases is below a hot susceptor). This study aims to investigate thermo-kinetic phenomena taking place during the GaN (gallium nitride) growth process using [...] Read more.
The present paper focuses on the high-pressure metal-organic vapor phase epitaxy (MOVPE) upside-down vertical reactor (where the inlet of cold gases is below a hot susceptor). This study aims to investigate thermo-kinetic phenomena taking place during the GaN (gallium nitride) growth process using trimethylgallium and ammonia at a pressure of above 2 bar. High pressure accelerates the growth process, but it results in poor thickness and quality in the obtained layers; hence, understanding the factors influencing non-uniformity is crucial. The present investigations have been conducted with the aid of ANSYS Fluent finite volume method commercial software. The obtained results confirm the possibility of increasing the growth rate by more than six times through increasing the pressure from 0.5 bar to 2.5 bar. The analysis shows which zones vortexes form in. Special attention should be paid to the transitional flow within the growth zone as well as the viewport. Furthermore, the normal reactor design cannot be used under the considered conditions, even for the lower pressure value of 0.5 bar, due to high turbulences. Full article
(This article belongs to the Special Issue Nitride Semiconductors Revolution: Material, Devices and Applications)
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20 pages, 616 KiB  
Article
Fragmentation-Aware Traffic Grooming with Lane Changes in Spectrally–Spatially Flexible Optical Networks
by Piotr Lechowicz, Aleksandra Knapińska and Róża Goścień
Electronics 2021, 10(12), 1502; https://doi.org/10.3390/electronics10121502 - 21 Jun 2021
Cited by 4 | Viewed by 1740
Abstract
Traffic in current networks is constantly increasing due to the growing popularity of various network services. The currently deployed backbone optical networks apply wavelength division multiplexing (WDM) techniques in single-core single-mode fibers (SMFs) to transmit the light. However, the capacity of SMFs is [...] Read more.
Traffic in current networks is constantly increasing due to the growing popularity of various network services. The currently deployed backbone optical networks apply wavelength division multiplexing (WDM) techniques in single-core single-mode fibers (SMFs) to transmit the light. However, the capacity of SMFs is limited due to physical constraints, and new technologies are required in the near future. Spectrally–spatially-flexible optical networks (SS-FONs) are proposed to provide a substantial capacity increase by exploring the spatial dimension. However, before this technology will reach maturity, various aspects need to be addressed. In particular, during traffic grooming, multiple small requests are aggregated into large-capacity optical corridors in an optical layer to increase the spectral efficiency. As the summary traffic volume is dynamically changing, it may be required to set up and tear down optical channels, which results in network fragmentation. As a consequence, in a congested network, part of the requests can be blocked due to the lack of spectrum resources. Thus, the grooming of traffic and the creation of lightpaths should be carefully designed to minimize network fragmentation. In this study, we present several fragmentation metrics and develop a fragmentation-aware traffic grooming algorithm that reduces the bandwidth blocking probability. Full article
(This article belongs to the Special Issue Telecommunication Networks)
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17 pages, 8457 KiB  
Article
A New RBF Neural Network-Based Fault-Tolerant Active Control for Fractional Time-Delayed Systems
by Bo Wang, Hadi Jahanshahi, Christos Volos, Stelios Bekiros, Muhammad Altaf Khan, Praveen Agarwal and Ayman A. Aly
Electronics 2021, 10(12), 1501; https://doi.org/10.3390/electronics10121501 - 21 Jun 2021
Cited by 51 | Viewed by 2733
Abstract
Recently, intelligent control techniques have received considerable attention. In most studies, the systems’ model is assumed to be without any delay, and the effects of faults and failure in actuators are ignored. However, in real practice, sensor malfunctioning, mounting limitation, and defects in [...] Read more.
Recently, intelligent control techniques have received considerable attention. In most studies, the systems’ model is assumed to be without any delay, and the effects of faults and failure in actuators are ignored. However, in real practice, sensor malfunctioning, mounting limitation, and defects in actuators bring about faults, failure, delay, and disturbances. Consequently, applying controllers that do not consider these problems could significantly deteriorate controllers’ performance. In order to address this issue, in the current paper, we propose a new neural network-based fault-tolerant active control for fractional time-delayed systems. The neural network estimator is integrated with active control to compensate for all uncertainties and disturbances. The suggested method’s stability is achieved based on the concept of active control and the Lyapunov stability theorem. Then, a fractional-order memristor system is investigated, and some characteristics of this chaotic system are studied. Lastly, by applying the proposed control scheme, synchronization results of the fractional time-delayed memristor system in the presence of faults and uncertainties are studied. The simulation results suggest the effectiveness of the proposed control technique for uncertain time-delayed nonlinear systems. Full article
(This article belongs to the Special Issue Recent Advances in Chaotic Systems and Their Security Applications)
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39 pages, 3681 KiB  
Article
RYEL: An Experimental Study in the Behavioral Response of Judges Using a Novel Technique for Acquiring Higher-Order Thinking Based on Explainable Artificial Intelligence and Case-Based Reasoning
by Luis Raúl Rodríguez Oconitrillo, Juan José Vargas, Arturo Camacho, Álvaro Burgos and Juan Manuel Corchado
Electronics 2021, 10(12), 1500; https://doi.org/10.3390/electronics10121500 - 21 Jun 2021
Cited by 5 | Viewed by 2766
Abstract
The need for studies connecting machine explainability with human behavior is essential, especially for a detailed understanding of a human’s perspective, thoughts, and sensations according to a context. A novel system called RYEL was developed based on Subject-Matter Experts (SME) to investigate new [...] Read more.
The need for studies connecting machine explainability with human behavior is essential, especially for a detailed understanding of a human’s perspective, thoughts, and sensations according to a context. A novel system called RYEL was developed based on Subject-Matter Experts (SME) to investigate new techniques for acquiring higher-order thinking, the perception, the use of new computational explanatory techniques, support decision-making, and the judge’s cognition and behavior. Thus, a new spectrum is covered and promises to be a new area of study called Interpretation-Assessment/Assessment-Interpretation (IA-AI), consisting of explaining machine inferences and the interpretation and assessment from a human. It allows expressing a semantic, ontological, and hermeneutical meaning related to the psyche of a human (judge). The system has an interpretative and explanatory nature, and in the future, could be used in other domains of discourse. More than 33 experts in Law and Artificial Intelligence validated the functional design. More than 26 judges, most of them specializing in psychology and criminology from Colombia, Ecuador, Panama, Spain, Argentina, and Costa Rica, participated in the experiments. The results of the experimentation have been very positive. As a challenge, this research represents a paradigm shift in legal data processing. Full article
(This article belongs to the Special Issue 10th Anniversary of Electronics: Recent Advances in Computer Science & Engineering)
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20 pages, 3454 KiB  
Article
Intelligent Multi-Robot System for Collaborative Object Transportation Tasks in Rough Terrains
by Daegyun Choi and Donghoon Kim
Electronics 2021, 10(12), 1499; https://doi.org/10.3390/electronics10121499 - 21 Jun 2021
Cited by 7 | Viewed by 2561
Abstract
Human missions on other planets require constructing outposts and infrastructures, and one may need to consider relocating such large objects according to changes in mission spots. A multi-robot system would be a good option for such a transportation task because it can carry [...] Read more.
Human missions on other planets require constructing outposts and infrastructures, and one may need to consider relocating such large objects according to changes in mission spots. A multi-robot system would be a good option for such a transportation task because it can carry massive objects and provide better system reliability and redundancy when compared to a single robot system. This paper proposes an intelligent and decentralized approach for the multi-robot system using a genetic fuzzy system to perform an object transportation mission that not only minimizes the total travel distance of the multi-robot system but also guarantees the stability of the whole system in a rough terrain environment. The proposed fuzzy inference system determines the multi-robot system’s input for transporting an object to a target position and is tuned in the training process by a genetic algorithm with an artificially generated structured environment employing multiple scenarios. It validates the optimality of the proposed approach by comparing the training results with the results obtained by solving the formulated optimal control problem subject to path inequality constraints. It highlights the performance of the proposed approach by applying the trained fuzzy inference systems to operate the multi-robot system in unstructured environments. Full article
(This article belongs to the Special Issue Guidance, Navigation, and Fault-Tolerant Control of Autonomous Systems)
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20 pages, 2415 KiB  
Article
Vulnerability Analysis to Maximize the Resilience of Power Systems Considering Demand Response and Distributed Generation
by Darin Jairo Mosquera Palacios, Edwin Rivas Trujillo and Jesús María López-Lezama
Electronics 2021, 10(12), 1498; https://doi.org/10.3390/electronics10121498 - 21 Jun 2021
Cited by 7 | Viewed by 1819
Abstract
Electric power systems are subject to failures, due to both deliberate and fortuitous events. This paper addresses the first case in which a disruptive agent aims at maximizing the damage to the network (expressed through the total cost of operation), while the system [...] Read more.
Electric power systems are subject to failures, due to both deliberate and fortuitous events. This paper addresses the first case in which a disruptive agent aims at maximizing the damage to the network (expressed through the total cost of operation), while the system operator takes the necessary measures to mitigate the effects of this attack. The interaction between these two agents is modeled by means of a bi-level optimization problem. On one hand, the disruptive agent is positioned in the upper-level optimization problem and must decide which elements to render out of service (lines and generators), given a limited destructive budget. On the other hand, the system operator, located in a lower-level optimization problem, reacts to the attack by deploying mitigation measures in order to minimize cost overruns in system operation. Based on the aforementioned dynamic, this paper proposes a novel approach to maximize the resiliency of the power system under intentional attacks through the implementation of distributed energy resources (DERs), namely, distributed generation (DG) and demand response (DR). Three metrics are proposed to assess resilience by assigning DERs in islands generated by the destruction of lines and generators. The results obtained in a didactic 5-bus test system and the IEEE RTS-24 bus test system demonstrate the applicability and effectiveness of the proposed methodology. Full article
(This article belongs to the Special Issue Power System Simulation with Renewable Power: Protection, Optimization and Control)
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18 pages, 2219 KiB  
Article
State of Health Prediction of Lithium-Ion Batteries Based on the Discharge Voltage and Temperature
by Yanru Yang, Jie Wen, Yuanhao Shi and Jianchao Zeng
Electronics 2021, 10(12), 1497; https://doi.org/10.3390/electronics10121497 - 21 Jun 2021
Cited by 19 | Viewed by 2651
Abstract
Accurate state of health (SOH) prediction of lithium-ion batteries is essential for battery health management. In this paper, a novel method of predicting the SOH of lithium-ion batteries based on the voltage and temperature in the discharging process is proposed to achieve the [...] Read more.
Accurate state of health (SOH) prediction of lithium-ion batteries is essential for battery health management. In this paper, a novel method of predicting the SOH of lithium-ion batteries based on the voltage and temperature in the discharging process is proposed to achieve the accurate prediction. Both the equal voltage discharge time and the temperature change during the discharge process are regarded as health indicators (HIs), and then, the Pearson and Spearman relational analysis methods are applied to evaluate the relevance between HIs and SOH. On this basis, we modify the relevance vector machine (RVM) to a multiple kernel relevance vector machine (MKRVM) by combining Gaussian with sigmoid function to improve the accuracy of SOH prediction. The particle swarm optimization (PSO) is used to find the optimal weight and kernel function parameters of MKRVM. The aging data from NASA Ames Prognostics Center of Excellence are used to verify the effectiveness and accuracy of the proposed method in numerical simulations, whose results show that the MKRVM method has higher SOH prediction accuracy of lithium-ion batteries than the relevant methods. Full article
(This article belongs to the Section Power Electronics)
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20 pages, 2686 KiB  
Article
Analog Circuit Fault Diagnosis Based on Support Vector Machine Classifier and Fuzzy Feature Selection
by Hao Liang, Yiman Zhu, Dongyang Zhang, Le Chang, Yuming Lu, Xingfa Zhao and Yu Guo
Electronics 2021, 10(12), 1496; https://doi.org/10.3390/electronics10121496 - 21 Jun 2021
Cited by 7 | Viewed by 1946
Abstract
In analog circuit, the component parameters have tolerances and the fault component parameters present a wide distribution, which brings obstacle to classification diagnosis. To tackle this problem, this article proposes a soft fault diagnosis method combining the improved barnacles mating optimizer(BMO) algorithm with [...] Read more.
In analog circuit, the component parameters have tolerances and the fault component parameters present a wide distribution, which brings obstacle to classification diagnosis. To tackle this problem, this article proposes a soft fault diagnosis method combining the improved barnacles mating optimizer(BMO) algorithm with the support vector machine (SVM) classifier, which can achieve the minimum redundancy and maximum relevance for feature dimension reduction with fuzzy mutual information. To be concrete, first, the improved barnacles mating optimizer algorithm is used to optimize the parameters for learning and classification. We adopt six test functions that are on three data sets from the University of California, Irvine (UCI) machine learning repository to test the performance of SVM classifier with five different optimization algorithms. The results show that the SVM classifier combined with the improved barnacles mating optimizer algorithm is characterized with high accuracy in classification. Second, fuzzy mutual information, enhanced minimum redundancy, and maximum relevance principle are applied to reduce the dimension of the feature vector. Finally, a circuit experiment is carried out to verify that the proposed method can achieve fault classification effectively when the fault parameters are both fixed and distributed. The accuracy of the proposed fault diagnosis method is 92.9% when the fault parameters are distributed, which is 1.8% higher than other classifiers on average. When the fault parameters are fixed, the accuracy rate is 99.07%, which is 0.7% higher than other classifiers on average. Full article
(This article belongs to the Section Circuit and Signal Processing)
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13 pages, 5765 KiB  
Article
Sensorial Multifunctional Panels for Smart Factory Applications
by Leonardo Pantoli, Tullio Gabriele, Fabrizio Fiore Donati, Luciano Mastrodicasa, Pierluigi De Berardinis, Marianna Rotilio, Federica Cucchiella, Alfiero Leoni and Vincenzo Stornelli
Electronics 2021, 10(12), 1495; https://doi.org/10.3390/electronics10121495 - 21 Jun 2021
Cited by 4 | Viewed by 1771
Abstract
The use of Key Enabling Technologies (KET), in the definition of innovative systems, is a crucial point for smart industries and sustainability. The proposed work combines innovations from different fields, including industrial sustainability on the one hand, and smart electronics on the other. [...] Read more.
The use of Key Enabling Technologies (KET), in the definition of innovative systems, is a crucial point for smart industries and sustainability. The proposed work combines innovations from different fields, including industrial sustainability on the one hand, and smart electronics on the other. An innovative multifunctional panel is presented, produced with waste resulting from the industrial processing of paper and cardboard; the panel can be used for the control of safety in processing factories and for the monitoring of environmental conditions in the area, as well as the energy improvement of the building envelope. Several sensors are embedded in the panel for monitoring temperature, moisture, and localization by means of an RFID tag. In addition, the panel is battery–free, thus enhancing the installation and realization of the system. The power supply is provided by the tag reader as irradiated power, thus realizing a very low power application. Panels have been already realized and experimental tests have been performed in the laboratory. Full article
(This article belongs to the Special Issue Application of Wireless Sensor Networks in Accredited Monitoring)
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12 pages, 2695 KiB  
Article
Temperature Dependent Analytical Model for the Threshold Voltage of the SiC VJFET with a Lateral Asymmetric Channel
by Sami Ghedira, Abdelaali Fargi and Kamel Besbes
Electronics 2021, 10(12), 1494; https://doi.org/10.3390/electronics10121494 - 21 Jun 2021
Cited by 1 | Viewed by 1833
Abstract
The wide-bandgap (WBG) semiconductor devices for modern power electronics require intensive efforts for the analysis of the critical aspects of their operation. In recent years, silicon carbide (SiC) based field effect transistor have been extensively investigated. Motivated by the significant employment of the [...] Read more.
The wide-bandgap (WBG) semiconductor devices for modern power electronics require intensive efforts for the analysis of the critical aspects of their operation. In recent years, silicon carbide (SiC) based field effect transistor have been extensively investigated. Motivated by the significant employment of the SiC Vertical Junction Field Effect transistors with lateral channel (LC-VJFET) in the development of high-voltage and high temperature applications, the properties of the LC-VJFET device are investigated in this work. The most important normally-ON LC-VJFET parameter is their threshold voltage (VTh), which is defined as the gate-to-source voltage necessary to block the device. The higher complexity of the blocking operation of the normally-ON device makes the accurate knowledge of the VTh as a fundamental issue. In this paper, a temperature dependent analytical model for the threshold voltage of the normally-ON LC-VJFET is developed. This analytical model is derived based on a numerical analysis of the electrical potential distribution along the asymmetrical lateral channel in the blocking operation. To validate our model, the analytical results are compared to 2D numerical simulations and experimental results for a wide temperature range. Full article
(This article belongs to the Special Issue Electrical Characterization of Wide Bandgap Devices for Modern Power Electronics)
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21 pages, 596 KiB  
Article
A Comparative Analysis of Wi-Fi Offloading and Cooperation in Small-Cell Network
by Ayesha Ayub, Sobia Jangsher, M. Majid Butt, Abdur Rahman Maud and Farrukh A. Bhatti
Electronics 2021, 10(12), 1493; https://doi.org/10.3390/electronics10121493 - 21 Jun 2021
Cited by 3 | Viewed by 1873
Abstract
Small cells deliver cost-effective capacity and coverage enhancement in a cellular network. In this work, we present the interplay of two technologies, namely Wi-Fi offloading and small-cell cooperation that help in achieving this goal. Both these technologies are also being considered for 5G [...] Read more.
Small cells deliver cost-effective capacity and coverage enhancement in a cellular network. In this work, we present the interplay of two technologies, namely Wi-Fi offloading and small-cell cooperation that help in achieving this goal. Both these technologies are also being considered for 5G and B5G (Beyond 5G). We simultaneously consider Wi-Fi offloading and small-cell cooperation to maximize average user throughput in the small-cell network. We propose two heuristic methods, namely Sequential Cooperative Rate Enhancement (SCRE) and Sequential Offloading Rate Enhancement (SORE) to demonstrate cooperation and Wi-Fi offloading, respectively. SCRE is based on cooperative communication in which a user data rate requirement is satisfied through association with multiple small-cell base stations (SBSs). However, SORE is based on Wi-Fi offloading, in which users are offloaded to the nearest Wi-Fi Access Point and use its leftover capacity when they are unable to satisfy their rate constraint from a single SBS. Moreover, we propose an algorithm to switch between the two schemes (cooperation and Wi-Fi offloading) to ensure maximum average user throughput in the network. This is called the Switching between Cooperation and Offloading (SCO) algorithm and it switches depending upon the network conditions. We analyze these algorithms under varying requirements of rate threshold, number of resource blocks and user density in the network. The results indicate that SCRE is more beneficial for a sparse network where it also delivers relatively higher average data rates to cell-edge users. On the other hand, SORE is more advantageous in a dense network provided sufficient leftover Wi-Fi capacity is available and more users are present in the Wi-Fi coverage area. Full article
(This article belongs to the Special Issue Enabling Technologies for Internet of Things)
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16 pages, 5080 KiB  
Article
Deep Character-Level Anomaly Detection Based on a Convolutional Autoencoder for Zero-Day Phishing URL Detection
by Seok-Jun Bu and Sung-Bae Cho
Electronics 2021, 10(12), 1492; https://doi.org/10.3390/electronics10121492 - 21 Jun 2021
Cited by 25 | Viewed by 3650
Abstract
Considering the fatality of phishing attacks, the data-driven approach using massive URL observations has been verified, especially in the field of cyber security. On the other hand, the supervised learning approach relying on known attacks has limitations in terms of robustness against zero-day [...] Read more.
Considering the fatality of phishing attacks, the data-driven approach using massive URL observations has been verified, especially in the field of cyber security. On the other hand, the supervised learning approach relying on known attacks has limitations in terms of robustness against zero-day phishing attacks. Moreover, it is known that it is critical for the phishing detection task to fully exploit the sequential features from the URL characters. Taken together, to ensure both sustainability and intelligibility, we propose the combination of a convolution operation to model the character-level URL features and a deep convolutional autoencoder (CAE) to consider the nature of zero-day attacks. Extensive experiments on three real-world datasets consisting of 222,541 URLs showed the highest performance among the latest deep-learning methods. We demonstrated the superiority of the proposed method by receiver-operating characteristic (ROC) curve analysis in addition to 10-fold cross-validation and confirmed that the sensitivity improved by 3.98% compared to the latest deep model. Full article
(This article belongs to the Special Issue Data Security)
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18 pages, 2285 KiB  
Review
Virtual to Real-World Transfer Learning: A Systematic Review
by Mahesh Ranaweera and Qusay H. Mahmoud
Electronics 2021, 10(12), 1491; https://doi.org/10.3390/electronics10121491 - 21 Jun 2021
Cited by 22 | Viewed by 3849
Abstract
Machine learning has become an important research area in many domains and real-world applications. The prevailing assumption in traditional machine learning techniques, that training and testing data should be of the same domain, is a challenge. In the real world, gathering enough training [...] Read more.
Machine learning has become an important research area in many domains and real-world applications. The prevailing assumption in traditional machine learning techniques, that training and testing data should be of the same domain, is a challenge. In the real world, gathering enough training data to create high-performance learning models is not easy. Sometimes data are not available, very expensive, or dangerous to collect. In this scenario, the concept of machine learning does not hold up to its potential. Transfer learning has recently gained much acclaim in the field of research as it has the capability to create high performance learners through virtual environments or by using data gathered from other domains. This systematic review defines (a) transfer learning; (b) discusses the recent research conducted; (c) the current status of transfer learning and finally, (d) discusses how transfer learning can bridge the gap between the virtual and real-world. Full article
(This article belongs to the Section Artificial Intelligence)
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14 pages, 905 KiB  
Article
AREEBA: An Area Efficient Binary Huff-Curve Architecture
by Asher Sajid, Muhammad Rashid, Sajjad Shaukat Jamal, Malik Imran, Saud S. Alotaibi and Mohammed H. Sinky
Electronics 2021, 10(12), 1490; https://doi.org/10.3390/electronics10121490 - 20 Jun 2021
Cited by 4 | Viewed by 1759
Abstract
Elliptic curve cryptography is the most widely employed class of asymmetric cryptography algorithm. However, it is exposed to simple power analysis attacks due to the lack of unifiedness over point doubling and addition operations. The unified crypto systems such as Binary Edward, Hessian [...] Read more.
Elliptic curve cryptography is the most widely employed class of asymmetric cryptography algorithm. However, it is exposed to simple power analysis attacks due to the lack of unifiedness over point doubling and addition operations. The unified crypto systems such as Binary Edward, Hessian and Huff curves provide resistance against power analysis attacks. Furthermore, Huff curves are more secure than Edward and Hessian curves but require more computational resources. Therefore, this article has provided a low area hardware architecture for point multiplication computation of Binary Huff curves over GF(2163) and GF(2233). To achieve this, a segmented least significant digit multiplier for polynomial multiplications is proposed. In order to provide a realistic and reasonable comparison with state of the art solutions, the proposed architecture is modeled in Verilog and synthesized for different field programmable gate arrays. For Virtex-4, Virtex-5, Virtex-6, and Virtex-7 devices, the utilized hardware resources in terms of hardware slices over GF(2163) are 5302, 2412, 2982 and 3508, respectively. The corresponding achieved values over GF(2233) are 11,557, 10,065, 4370 and 4261, respectively. The reported low area values provide the acceptability of this work in area-constrained applications. Full article
(This article belongs to the Section Computer Science & Engineering)
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15 pages, 4345 KiB  
Review
A Comparison Review on Transmission Mode for Onshore Integration of Offshore Wind Farms: HVDC or HVAC
by Syed Rahman, Irfan Khan, Hend I. Alkhammash and Muhammad Faisal Nadeem
Electronics 2021, 10(12), 1489; https://doi.org/10.3390/electronics10121489 - 20 Jun 2021
Cited by 24 | Viewed by 4415
Abstract
The development of offshore wind farms (WF) is inevitable as they have exceptional resistance against climate change and produce clean energy without hazardous wastes. The offshore WF usually has a bigger generation capacity with less environmental impacts, and it is more reliable too [...] Read more.
The development of offshore wind farms (WF) is inevitable as they have exceptional resistance against climate change and produce clean energy without hazardous wastes. The offshore WF usually has a bigger generation capacity with less environmental impacts, and it is more reliable too due to stronger and consistent sea winds. The early offshore WF installations are located near the shore, whereas most modern installations are located far away from shore, generating higher power. This paradigm shift has forced the researchers and industry personnel to look deeper into transmission options, namely, high voltage AC transmission (HVAC) and high voltage DC transmission (HVDC). This evaluation can be both in terms of power carrying capability as well as cost comparisons. Additionally, different performance requirements such as power rating, onshore grid requirements, reactive power compensation, etc., must be considered for evaluation. This paper elaborately reviews and explains the offshore wind farm structure and performance requirements for bulk offshore power transfer. Based on the structure and performance requirements, both HVDC and HVAC transmission modes are compared and analyzed critically. Finally, a criterion for selection and increasing popularity of HVDC transmission is established. Full article
(This article belongs to the Special Issue Modeling, Control, and Optimization of Power Electronics)
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6 pages, 2203 KiB  
Article
Triple-Band Uniform Circular Array Antenna for a Multi-Functional Radar System
by Ilkyu Kim, Sun-Gyu Lee and Jeong-Hae Lee
Electronics 2021, 10(12), 1488; https://doi.org/10.3390/electronics10121488 - 20 Jun 2021
Cited by 4 | Viewed by 2402
Abstract
A phased array radar has been developed toward an effective means for integrating multiple functionalities into one radar platform. The radar system necessitates the ability to operate at multiple frequencies simultaneously. In this paper, a triple-band uniform radial sub-array using a shared aperture [...] Read more.
A phased array radar has been developed toward an effective means for integrating multiple functionalities into one radar platform. The radar system necessitates the ability to operate at multiple frequencies simultaneously. In this paper, a triple-band uniform radial sub-array using a shared aperture antenna is proposed for a multi-functional radar system. An efficient placement of different radiating elements is realized based on the radial displacement of the circular array. In addition, multi-layer feed networks are used to reduce the intricacy of integrating several feed networks into one antenna. The reasonable matching characteristics and far-field gain are acquired at the S-band, C-band, and X-band. The measured results of the prototype are presented, and the results are compared to the simulation, which showed a good agreement. Full article
(This article belongs to the Special Issue Design and Theoretical Study of New Antennas)
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16 pages, 446 KiB  
Article
Anti-Disturbance Fault-Tolerant Sliding Mode Control for Systems with Unknown Faults and Disturbances
by Xiaoli Zhang, Zhengyu Zhu and Yang Yi
Electronics 2021, 10(12), 1487; https://doi.org/10.3390/electronics10121487 - 20 Jun 2021
Cited by 2 | Viewed by 1758
Abstract
In this paper, a novel control algorithm with the capacity of fault tolerance and anti-disturbance is discussed for the systems subjected to actuator faults and mismatched disturbances. The fault diagnosis observer (FDO) and the disturbance observer (DO) are successively designed to estimate the [...] Read more.
In this paper, a novel control algorithm with the capacity of fault tolerance and anti-disturbance is discussed for the systems subjected to actuator faults and mismatched disturbances. The fault diagnosis observer (FDO) and the disturbance observer (DO) are successively designed to estimate the dynamics of unknown faults and disturbances. Furthermore, with the help of the observed information, a sliding surface and the corresponding sliding mode controller are proposed to compensate the actuator faults and eliminate the impact of mismatched disturbances simultaneously. Meanwhile, the convex optimization algorithm is discussed to guarantee the stability of the controlled system. The favorable anti-disturbance and fault-tolerant results can also be proved. Finally, the validity of the algorithm is certified by the simulation results for typical unmanned aerial vehicles (UAV) systems. Full article
(This article belongs to the Special Issue Advancement of Fault Detection/Diagnosis and Fault-Tolerant Control with Applications)
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22 pages, 21204 KiB  
Article
Gradual Wear Diagnosis of Outer-Race Rolling Bearing Faults through Artificial Intelligence Methods and Stray Flux Signals
by Israel Zamudio-Ramirez, Roque A. Osornio-Rios, Jose A. Antonino-Daviu, Jonathan Cureño-Osornio and Juan-Jose Saucedo-Dorantes
Electronics 2021, 10(12), 1486; https://doi.org/10.3390/electronics10121486 - 20 Jun 2021
Cited by 11 | Viewed by 2200
Abstract
Electric motors have been widely used as fundamental elements for driving kinematic chains on mechatronic systems, which are very important components for the proper operation of several industrial applications. Although electric motors are very robust and efficient machines, they are prone to suffer [...] Read more.
Electric motors have been widely used as fundamental elements for driving kinematic chains on mechatronic systems, which are very important components for the proper operation of several industrial applications. Although electric motors are very robust and efficient machines, they are prone to suffer from different faults. One of the most frequent causes of failure is due to a degradation on the bearings. This fault has commonly been diagnosed at advanced stages by means of vibration and current signals. Since low-amplitude fault-related signals are typically obtained, the diagnosis of faults at incipient stages turns out to be a challenging task. In this context, it is desired to develop non-invasive techniques able to diagnose bearing faults at early stages, enabling to achieve adequate maintenance actions. This paper presents a non-invasive gradual wear diagnosis method for bearing outer-race faults. The proposal relies on the application of a linear discriminant analysis (LDA) to statistical and Katz’s fractal dimension features obtained from stray flux signals, and then an automatic classification is performed by means of a feed-forward neural network (FFNN). The results obtained demonstrates the effectiveness of the proposed method, which is validated on a kinematic chain (composed by a 0.746 KW induction motor, a belt and pulleys transmission system and an alternator as a load) under several operation conditions: healthy condition, 1 mm, 2 mm, 3 mm, 4 mm, and 5 mm hole diameter on the bearing outer race, and 60 Hz, 50 Hz, 15 Hz and 5 Hz power supply frequencies Full article
(This article belongs to the Special Issue Fault Diagnosis and Prognosis of Mechatronic Systems Using Artificial Intelligence and Estimation Theory)
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29 pages, 5514 KiB  
Review
Topological Review of Quasi-Switched Boost Inverters
by JG Nataraj Barath, Ayyasamy Soundarrajan, Serhii Stepenko, Oleksandr Husev, Dmitri Vinnikov and Minh-Khai Nguyen
Electronics 2021, 10(12), 1485; https://doi.org/10.3390/electronics10121485 - 20 Jun 2021
Cited by 11 | Viewed by 3054
Abstract
This paper presents a comprehensive review based on the features and drawbacks of the quasi-switched boost inverter (qSBI) topologies. The qSBI derived configurations are well suitable for low power applications due to their reduced number of components. This work focuses on the topological [...] Read more.
This paper presents a comprehensive review based on the features and drawbacks of the quasi-switched boost inverter (qSBI) topologies. The qSBI derived configurations are well suitable for low power applications due to their reduced number of components. This work focuses on the topological review of qSBI derived topologies and serves as a reference for further derivation and research on the selection of suitable topology for the specific renewable energy applications, particularly based on the photovoltaic (PV) converters. Full article
(This article belongs to the Special Issue Industrial Applications of Power Electronics II)
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23 pages, 1056 KiB  
Article
Collision Avoidance Geographic P2P-RPL in Multi-Hop Indoor Wireless Networks
by Yunyoung Choi, Jaehyung Park, Jiwon Jung and Younggoo Kwon
Electronics 2021, 10(12), 1484; https://doi.org/10.3390/electronics10121484 - 20 Jun 2021
Cited by 2 | Viewed by 1500
Abstract
In home and building automation applications, wireless sensor devices need to be connected via unreliable wireless links within a few hundred milliseconds. Routing protocols in Low-power and Lossy Networks (LLNs) need to support reliable data transmission with an energy-efficient manner and short routing [...] Read more.
In home and building automation applications, wireless sensor devices need to be connected via unreliable wireless links within a few hundred milliseconds. Routing protocols in Low-power and Lossy Networks (LLNs) need to support reliable data transmission with an energy-efficient manner and short routing convergence time. IETF standardized the Point-to-Point RPL (P2P-RPL) routing protocol, in which P2P-RPL propagates the route discovery messages over the whole network. This leads to significant routing control packet overhead and a large amount of energy consumption. P2P-RPL uses the trickle algorithm to control the transmission rate of routing control packets. The non-deterministic message suppression nature of the trickle algorithm may generate a sub-optimal routing path. The listen-only period of the trickle algorithm may lead to a long network convergence time. In this paper, we propose Collision Avoidance Geographic P2P-RPL, which achieves energy-efficient P2P data delivery with a fast routing request procedure. The proposed algorithm uses the location information to limit the network search space for the desired route discovery to a smaller location-constrained forwarding zone. The Collision Avoidance Geographic P2P-RPL also dynamically selects the listen-only period of the trickle timer algorithm based on the transmission priority related to geographic position information. The location information of each node is obtained from the Impulse-Response Ultra-WideBand (IR-UWB)-based cooperative multi-hop self localization algorithm. We implement Collision Avoidance Geographic P2P-RPL on Contiki OS, an open-source operating system for LLNs and the Internet of Things. The performance results show that the Collision Avoidance Geographic P2P-RPL reduced the routing control packet overheads, energy consumption, and network convergence time significantly. The cooperative multi-hop self localization algorithm improved the practical implementation characteristics of the P2P-RPL protocol in real world environments. The collision avoidance algorithm using the dynamic trickle timer increased the operation efficiency of the P2P-RPL under various wireless channel conditions with a location-constrained routing space. Full article
(This article belongs to the Special Issue IoT Sensor Network Application)
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19 pages, 4735 KiB  
Article
Hybrid Multicarrier Random Space Vector PWM for the Mitigation of Acoustic Noise
by P. Madasamy, Rajesh Verma, C. Bharatiraja, Barnabas Paul Glady J., T. Srihari, Josiah Lange Munda and Lucian Mihet-Popa
Electronics 2021, 10(12), 1483; https://doi.org/10.3390/electronics10121483 - 19 Jun 2021
Cited by 4 | Viewed by 3114
Abstract
The pulse width modulation (PWM) inverter is an obvious choice for any industrial and power sector application. Particularly, industrial drives benefit from the higher DC-link utilization, acoustic noise, and vibration industrial standards. Many PWM techniques have been proposed to meet the drives’ demand [...] Read more.
The pulse width modulation (PWM) inverter is an obvious choice for any industrial and power sector application. Particularly, industrial drives benefit from the higher DC-link utilization, acoustic noise, and vibration industrial standards. Many PWM techniques have been proposed to meet the drives’ demand for higher DC-link utilization and lower harmonics suppression and noise reductions. Still, random PWM (RPWM) is the best candidate for reducing the acoustic noises. Few RPWM (RPWM) methods have been developed and investigated for the AC drive’s PWM inverter. However, due to the lower randomness of the multiple frequency harmonics spectrum, reducing the drive noise is still challenging. These PWMs dealt with the spreading harmonics, thereby decreasing the harmonic effects on the system. However, these techniques are unsuccessful at maintaining the higher DC-link utilizations. Existing RPWM methods have less randomness and need complex digital circuitry. Therefore, this paper mainly deals with a combined RPWM principle in space vector PWM (SVPWM) to generate random PWM generation using an asymmetric frequency multicarrier called multicarrier random space vector PWM (MCRSVPWM). he SVPWM switching vectors with different frequency carrier are chosen with the aid of a random bi-nary bit generator. The proposed MCRSVPWM generates the pulses with a randomized triangular carrier (1 to 4 kHz), while the conventional RPWM method contains a random pulse position with a fixed frequency triangular carrier. The proposed PWM is capable of eradicating the high-frequency unpleasant acoustic noise more effectually than conventional RPWM with a shorter random frequency range. The simulation study is performed through MATLAB/Simulink for a 2 kW asynchronous induction motor drive. Experimental validation of the proposed MCRSVPWM is tested with a 2 kW six-switch (Power MOSFET–SCH2080KE) inverter power module-fed induction motor drive. Full article
(This article belongs to the Section Power Electronics)
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16 pages, 9144 KiB  
Article
A Sub-6G SP32T Single-Chip Switch with Nanosecond Switching Speed for 5G Applications in 0.25 μm GaAs Technology
by Tianxiang Wu, Jipeng Wei, Hongquan Liu, Shunli Ma, Yong Chen and Junyan Ren
Electronics 2021, 10(12), 1482; https://doi.org/10.3390/electronics10121482 - 19 Jun 2021
Cited by 9 | Viewed by 3372
Abstract
This paper presents a single-pole 32-throw (SP32T) switch with an operating frequency of up to 6 GHz for 5G communication applications. Compared to the traditional SP32T module implemented by the waveguide package with large volume and power, the proposed switch can significantly simplify [...] Read more.
This paper presents a single-pole 32-throw (SP32T) switch with an operating frequency of up to 6 GHz for 5G communication applications. Compared to the traditional SP32T module implemented by the waveguide package with large volume and power, the proposed switch can significantly simplify the system with a smaller size and light weight. The proposed SP32T scheme utilizing tree structure can dramatically reduce the dc power and enhance isolation between different output ports, which makes it suitable for low-power 5G communication. A design methodology of a novel transmission (ABCD) matrix is proposed to optimize the switch, which can achieve low insertion loss and high isolation simultaneously. The average insertion loss and the isolations are 1.5 and 35 dB at 6 GHz operating frequency, respectively. The switch exhibits the measured input return loss which is better than 10 dB at 6 GHz. The 1 dB input compression point of SP32T is 15 dBm. The prototype is designed in 5 V 0.25 μm GaAs technology and occupies a small area of 12 mm2. Full article
(This article belongs to the Section Circuit and Signal Processing)
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23 pages, 15901 KiB  
Article
Distance Protection for Coexistence of 5G Base Station and Satellite Earth Station
by Yiqiao Wei, Shuzhi Liu and Seung-Hoon Hwang
Electronics 2021, 10(12), 1481; https://doi.org/10.3390/electronics10121481 - 19 Jun 2021
Cited by 11 | Viewed by 2908
Abstract
In this paper, we investigate the coexistence of the 5G communication network with a fixed-satellite service (FSS) in the 3.5 GHz and 26 GHz frequency bands. We analyze a distance protection scheme for the FSS Earth station (ES) and 5G base stations (BS). [...] Read more.
In this paper, we investigate the coexistence of the 5G communication network with a fixed-satellite service (FSS) in the 3.5 GHz and 26 GHz frequency bands. We analyze a distance protection scheme for the FSS Earth station (ES) and 5G base stations (BS). Furthermore, we define the exclusion and restriction zones to develop a transmit power control scheme based on the Citizens Broadband Radio Service (CBRS). An interactive power control scheme is also devised for the restriction zone and extensively analyzed through simulations. The proposed scheme is examined for practical scenarios such as the rural macrocells (RMa), urban macrocells (UMa), and urban microcells (UMi) as defined by the 3GPP. The impact of the antenna type is also investigated, and BSs with omnidirectional, 4 × 4, 8 × 8, and 16 × 16 antenna arrays are examined, as defined by 3GPP, for the 5G networks. The results confirm that 5G systems can coexist with the FSS and provide quantitative insights into the selection of the system parameters, including interference margins, exclusion sizes, and reduction zones, for different scenarios and antenna types. Full article
(This article belongs to the Special Issue Innovative Technologies in Telecommunication)
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21 pages, 11829 KiB  
Article
Implementing a Gaze Tracking Algorithm for Improving Advanced Driver Assistance Systems
by Agapito Ledezma, Víctor Zamora, Óscar Sipele, M. Paz Sesmero and Araceli Sanchis
Electronics 2021, 10(12), 1480; https://doi.org/10.3390/electronics10121480 - 19 Jun 2021
Cited by 14 | Viewed by 3199
Abstract
Car accidents are one of the top ten causes of death and are produced mainly by driver distractions. ADAS (Advanced Driver Assistance Systems) can warn the driver of dangerous scenarios, improving road safety, and reducing the number of traffic accidents. However, having a [...] Read more.
Car accidents are one of the top ten causes of death and are produced mainly by driver distractions. ADAS (Advanced Driver Assistance Systems) can warn the driver of dangerous scenarios, improving road safety, and reducing the number of traffic accidents. However, having a system that is continuously sounding alarms can be overwhelming or confusing or both, and can be counterproductive. Using the driver’s attention to build an efficient ADAS is the main contribution of this work. To obtain this “attention value” the use of a Gaze tracking is proposed. Driver’s gaze direction is a crucial factor in understanding fatal distractions, as well as discerning when it is necessary to warn the driver about risks on the road. In this paper, a real-time gaze tracking system is proposed as part of the development of an ADAS that obtains and communicates the driver’s gaze information. The developed ADAS uses gaze information to determine if the drivers are looking to the road with their full attention. This work gives a step ahead in the ADAS based on the driver, building an ADAS that warns the driver only in case of distraction. The gaze tracking system was implemented as a model-based system using a Kinect v2.0 sensor and was adjusted on a set-up environment and tested on a suitable-features driving simulation environment. The average obtained results are promising, having hit ratios between 96.37% and 81.84%. Full article
(This article belongs to the Special Issue AI-Based Autonomous Driving System)
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15 pages, 2920 KiB  
Article
Estimation during Design Phases of Suitable SRAM Cells for PUF Applications Using Separatrix and Mismatch Metrics
by Abdel Alheyasat, Gabriel Torrens, Sebastià A. Bota and Bartomeu Alorda
Electronics 2021, 10(12), 1479; https://doi.org/10.3390/electronics10121479 - 19 Jun 2021
Cited by 3 | Viewed by 1750
Abstract
Physically unclonable functions (PUFs) are used as low-cost cryptographic primitives in device authentication and secret key creation. SRAM-PUFs are well-known as entropy sources; nevertheless, due of non-deterministic noise environment during the power-up process, they are subject to low challenge-response repeatability. The dependability of [...] Read more.
Physically unclonable functions (PUFs) are used as low-cost cryptographic primitives in device authentication and secret key creation. SRAM-PUFs are well-known as entropy sources; nevertheless, due of non-deterministic noise environment during the power-up process, they are subject to low challenge-response repeatability. The dependability of SRAM-PUFs is usually accomplished by combining complex error correcting codes (ECCs) with fuzzy extractor structures resulting in an increase in power consumption, area, cost, and design complexity. In this study, we established effective metrics on the basis of the separatrix concept and cell mismatch to estimate the percentage of cells that, due to the effect of variability, will tend to the same initial state during power-up. The effects of noise and temperature in cell start-up processes were used to validate the proposed metrics. The presented metrics may be applied at the SRAM-PUF design phases to investigate the impact of different design parameters on the percentage of reliable cells for PUF applications. Full article
(This article belongs to the Section Microelectronics)
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20 pages, 2117 KiB  
Article
Efficient Discovery of Periodic-Frequent Patterns in Columnar Temporal Databases
by Penugonda Ravikumar, Palla Likhitha, Bathala Venus Vikranth Raj, Rage Uday Kiran, Yutaka Watanobe and Koji Zettsu
Electronics 2021, 10(12), 1478; https://doi.org/10.3390/electronics10121478 - 19 Jun 2021
Cited by 14 | Viewed by 1975
Abstract
Discovering periodic-frequent patterns in temporal databases is a challenging problem of great importance in many real-world applications. Though several algorithms were described in the literature to tackle the problem of periodic-frequent pattern mining, most of these algorithms use the traditional horizontal (or row) [...] Read more.
Discovering periodic-frequent patterns in temporal databases is a challenging problem of great importance in many real-world applications. Though several algorithms were described in the literature to tackle the problem of periodic-frequent pattern mining, most of these algorithms use the traditional horizontal (or row) database layout, that is, either they need to scan the database several times or do not allow asynchronous computation of periodic-frequent patterns. As a result, this kind of database layout makes the algorithms for discovering periodic-frequent patterns both time and memory inefficient. One cannot ignore the importance of mining the data stored in a vertical (or columnar) database layout. It is because real-world big data is widely stored in columnar database layout. With this motivation, this paper proposes an efficient algorithm, Periodic Frequent-Equivalence CLass Transformation (PF-ECLAT), to find periodic-frequent patterns in a columnar temporal database. Experimental results on sparse and dense real-world and synthetic databases demonstrate that PF-ECLAT is memory and runtime efficient and highly scalable. Finally, we demonstrate the usefulness of PF-ECLAT with two case studies. In the first case study, we have employed our algorithm to identify the geographical areas in which people were periodically exposed to harmful levels of air pollution in Japan. In the second case study, we have utilized our algorithm to discover the set of road segments in which congestion was regularly observed in a transportation network. Full article
(This article belongs to the Special Issue Spatiotemporal Big Data Analytics)
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23 pages, 2198 KiB  
Article
autoCoin: Secure Content Sharing Based on Blockchain for Vehicular Cloud
by Wooseong Kim and Kyungho Ryu
Electronics 2021, 10(12), 1477; https://doi.org/10.3390/electronics10121477 - 19 Jun 2021
Cited by 5 | Viewed by 2128
Abstract
A future smart car will be more than a means of transportation, as it will not only move people to a destination without requiring them to drive but will enable people to work or enjoy a trip with entertainment. For this, smart vehicles [...] Read more.
A future smart car will be more than a means of transportation, as it will not only move people to a destination without requiring them to drive but will enable people to work or enjoy a trip with entertainment. For this, smart vehicles need to deal with various types of data for safety and infotainment, such as real-time traffic, multi-media contents, documents and weather information. Recently, a fleet of vehicles connected to other vehicles and infrastructure (i.e., road side units) using a legacy or 5G mmWave spectrum has been considered as a platform to cooperate for those new tasks, known as the vehicular cloud or fog. Within the vehicular cloud, data management should consider security, high availability and interoperability between vehicles. However, these are not easily achievable without a centralized service provider; it is difficult for an autonomous P2P system to guarantee data integrity, and it cannot compensate drivers that actively participate in the vehicular cloud. Fortunately, the many successes achieved in the field of crypto-currency raise the possibility of defining incentives that are necessary for a sustainable digital economy. In this paper, we propose autoCoin—an approach that aims to encourage smart vehicles to cooperate to create and exchange infotainment data securely under the assumption of rationality. We introduce a scalable blockchain architecture for autoCoin and a smart contract to exchange contents without third-parties using an off-chain technique. Full article
(This article belongs to the Special Issue Access Technology in 5G and Mobile Communication Networks)
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19 pages, 9721 KiB  
Article
8-Port Semi-Circular Arc MIMO Antenna with an Inverted L-Strip Loaded Connected Ground for UWB Applications
by Tathababu Addepalli, Arpan Desai, Issa Elfergani, N. Anveshkumar, Jayshri Kulkarni, Chemseddine Zebiri, Jonathan Rodriguez and Raed Abd-Alhameed
Electronics 2021, 10(12), 1476; https://doi.org/10.3390/electronics10121476 - 19 Jun 2021
Cited by 42 | Viewed by 3119
Abstract
Multiple-input multiple-output (MIMO) antennas with four and eight elements having connected grounds are designed for ultra-wideband applications. Careful optimization of the lines connecting the grounds leads to reduced mutual coupling amongst the radiating patches. The proposed antenna has a modified substrate geometry and [...] Read more.
Multiple-input multiple-output (MIMO) antennas with four and eight elements having connected grounds are designed for ultra-wideband applications. Careful optimization of the lines connecting the grounds leads to reduced mutual coupling amongst the radiating patches. The proposed antenna has a modified substrate geometry and comprises a circular arc-shaped conductive element on the top with the modified ground plane geometry. Polarization diversity and isolation are achieved by replicating the elements orthogonally forming a plus shape antenna structure. The modified ground plane consists of an inverted L strip and semi ellipse slot over the partial ground that helps the antenna in achieving effective wide bandwidth spanning from (117.91%) 2.84–11 GHz. Both 4/8-port antenna achieves a size of 0.61 λ × 0.61 λ mm2 (lowest frequency) where 4-port antenna is printed on FR4 substrate. The 4-port UWB MIMO antenna attains wide impedance bandwidth, Omni-directional pattern, isolation >15 dB, ECC < 0.015, and average gain >4.5 dB making the MIMO antenna suitable for portable UWB applications. Four element antenna structure is further extended to 8-element configuration with the connected ground where the decent value of IBW, isolation, and ECC is achieved. Full article
(This article belongs to the Special Issue Recent Advances in Antenna Design for 5G Heterogeneous Networks)
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19 pages, 1911 KiB  
Article
Multi-Touch Interaction Generation Device by Spatiotemporally Switching Electrodes
by Masahiro Okamoto and Kazuya Murao
Electronics 2021, 10(12), 1475; https://doi.org/10.3390/electronics10121475 - 19 Jun 2021
Viewed by 2076
Abstract
With the spread of devices equipped with touch panels, such as smartphones, tablets, and laptops, the opportunity for users to perform touch interaction has increased. In this paper, we constructed a device that generates multi-touch interactions to realize high-speed, continuous, or hands-free touch [...] Read more.
With the spread of devices equipped with touch panels, such as smartphones, tablets, and laptops, the opportunity for users to perform touch interaction has increased. In this paper, we constructed a device that generates multi-touch interactions to realize high-speed, continuous, or hands-free touch input on a touch panel. The proposed device consists of an electrode sheet printed with multiple electrodes using conductive ink and a voltage control board, and generates eight multi-touch interactions: tap, double-tap, long-press, press-and-tap, swipe, pinch-in, pinch-out, and rotation, by changing the capacitance of the touch panel in time and space. In preliminary experiments, we investigated the appropriate electrode size and spacing for generating multi-touch interactions, and then implemented the device. From the evaluation experiments, it was confirmed that the proposed device can generate multi-touch interactions with high accuracy. As a result, tap, press-and-tap, swipe, pinch-in, pinch-out, and rotation can be generated with a success rate of 100%. It was confirmed that all the multi-touch interactions evaluated by the proposed device could be generated with high accuracy and acceptable speed. Full article
(This article belongs to the Special Issue Human–Computer Interaction: Information and Interaction Design)
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