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Electronics, Volume 9, Issue 6 (June 2020) – 177 articles

Cover Story (view full-size image): A novel prototype radio frequency (RF) switch denoted as a magnetostatic responsive structure (MRS) is presented. Notably, the MRS does not need any biasing circuitry for switching but only requires a small magnetic force to operate. Circuit models and simulations are comparable with measurements, successfully validating this new technology. The MRS switch has potential applications in advanced wireless services (AWS) and 4G/5G antenna systems. View this paper
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13 pages, 1430 KiB  
Article
Photostimulation of Extravasation of Beta-Amyloid through the Model of Blood-Brain Barrier
by Ekaterina Zinchenko, Maria Klimova, Aysel Mamedova, Ilana Agranovich, Inna Blokhina, Tatiana Antonova, Andrey Terskov, Alexander Shirokov, Nikita Navolokin, Andrey Morgun, Elena Osipova, Elizaveta Boytsova, Tingting Yu, Dan Zhu, Juergen Kurths and Oxana Semyachkina-Glushkovskaya
Electronics 2020, 9(6), 1056; https://doi.org/10.3390/electronics9061056 - 26 Jun 2020
Cited by 17 | Viewed by 3268
Abstract
Alzheimer’s disease (AD) is an incurable pathology associated with progressive decline in memory and cognition. Phototherapy might be a new promising and alternative strategy for the effective treatment of AD, and has been actively discussed over two decades. However, the mechanisms of therapeutic [...] Read more.
Alzheimer’s disease (AD) is an incurable pathology associated with progressive decline in memory and cognition. Phototherapy might be a new promising and alternative strategy for the effective treatment of AD, and has been actively discussed over two decades. However, the mechanisms of therapeutic photostimulation (PS) effects on subjects with AD remain poorly understood. The goal of this study was to determine the mechanisms of therapeutic PS effects in beta-amyloid (Aβ)-injected mice. The neurological severity score and the new object recognition tests demonstrate that PS 9 J/cm2 attenuates the memory and neurological deficit in mice with AD. The immunohistochemical assay revealed a decrease in the level of Aβ in the brain and an increase of Aβ in the deep cervical lymph nodes obtained from mice with AD after PS. Using the in vitro model of the blood-brain barrier (BBB), we show a PS-mediated decrease in transendothelial resistance and in the expression of tight junction proteins as well an increase in the BBB permeability to Aβ. These findings suggest that a PS-mediated BBB opening and the activation of the lymphatic clearance of Aβ from the brain might be a crucial mechanism underlying therapeutic effects of PS in mice with AD. These pioneering data open new strategies in the development of non-pharmacological methods for therapy of AD and contribute to a better understanding of the PS effects on the central nervous system. Full article
(This article belongs to the Special Issue Advanced Laser Technologies for Biophotonics)
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20 pages, 5451 KiB  
Article
Indoor Localization System Based on Bluetooth Low Energy for Museum Applications
by Romeo Giuliano, Gian Carlo Cardarilli, Carlo Cesarini, Luca Di Nunzio, Francesca Fallucchi, Rocco Fazzolari, Franco Mazzenga, Marco Re and Alessandro Vizzarri
Electronics 2020, 9(6), 1055; https://doi.org/10.3390/electronics9061055 - 26 Jun 2020
Cited by 57 | Viewed by 10422
Abstract
In the last few years, indoor localization has attracted researchers and commercial developers. Indeed, the availability of systems, techniques and algorithms for localization allows the improvement of existing communication applications and services by adding position information. Some examples can be found in the [...] Read more.
In the last few years, indoor localization has attracted researchers and commercial developers. Indeed, the availability of systems, techniques and algorithms for localization allows the improvement of existing communication applications and services by adding position information. Some examples can be found in the managing of people and/or robots for internal logistics in very large warehouses (e.g., Amazon warehouses, etc.). In this paper, we study and develop a system allowing the accurate indoor localization of people visiting a museum or any other cultural institution. We assume visitors are equipped with a Bluetooth Low Energy (BLE) device (commonly found in modern smartphones or in a small chipset), periodically transmitting packets, which are received by geolocalized BLE receivers inside the museum area. Collected packets are provided to the locator server to estimate the positions of the visitors inside the museum. The position estimation is based on a feed-forward neural network trained by a measurement campaign in the considered environment and on a non-linear least square algorithm. We also provide a strategy for deploying the BLE receivers in a given area. The performance results obtained from measurements show an achievable position estimate accuracy below 1 m. Full article
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19 pages, 970 KiB  
Article
Outage Performance of Power Beacon-Aided Multi-Hop Cooperative Cognitive Radio Protocol Under Constraint of Interference and Hardware Noises
by Pham Minh Nam, Tran Trung Duy, Phan Van Ca, Pham Ngoc Son and Ngo Hoang An
Electronics 2020, 9(6), 1054; https://doi.org/10.3390/electronics9061054 - 26 Jun 2020
Cited by 9 | Viewed by 3152
Abstract
In this paper, we evaluate end-to-end outage probability of a multi-hop decode-and-forward relaying protocol in underlay cognitive radio network. In the proposed protocol, named COOP, secondary nodes including source and relays have to harvest radio-frequency energy from multiple secondary power beacons, and adjust [...] Read more.
In this paper, we evaluate end-to-end outage probability of a multi-hop decode-and-forward relaying protocol in underlay cognitive radio network. In the proposed protocol, named COOP, secondary nodes including source and relays have to harvest radio-frequency energy from multiple secondary power beacons, and adjust their transmit power, follows a pre-determined interference threshold given by multiple primary users. To enhance the outage performance for the secondary network under an joint constraint of the interference threshold, Rayleigh fading channel and hardware noises caused by imperfect transceiver hardware, the secondary relays on the source-destination path cooperate to forward the source data to the destination. Particularly, they attempt to receive the source data from their previous nodes, and forward it to the secondary destination if requested. Moreover, whenever the destination cannot receive the source data successfully, a successful relay that has the shortest distance to the destination is selected for retransmission. Due to usage of the cooperative transmission, the proposed COOP protocol obtains better performance, as compared with the corresponding multi-hop relaying one (denoted DIRECT) which only uses direct transmission at each hop. We evaluate the outage performance of COOP and DIRECT via both simulation and theory. The obtained results present a significant performance enhancement, as comparing COOP with DIRECT. Full article
(This article belongs to the Special Issue RF Energy Harvesting and Wireless Power Transfer)
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11 pages, 4904 KiB  
Article
Design of a High Voltage Pulse Generator with Large Width Adjusting Range for Tumor Treatment
by Xin Rao, Xiaodong Chen, Jun Zhou, Bo Zhang and Yasir Alfadhl
Electronics 2020, 9(6), 1053; https://doi.org/10.3390/electronics9061053 - 26 Jun 2020
Cited by 5 | Viewed by 5450
Abstract
The unique biological effects stimulated by short pulsed electric field have many applications in tumor treatment, such as irreversible electroporation, electrochemotherapy, gene transfection and immune therapy. These biological effects require high voltage pulses with different pulse width in the range from nanoseconds to [...] Read more.
The unique biological effects stimulated by short pulsed electric field have many applications in tumor treatment, such as irreversible electroporation, electrochemotherapy, gene transfection and immune therapy. These biological effects require high voltage pulses with different pulse width in the range from nanoseconds to hundreds of microseconds. To fulfill this requirement, a compact high voltage pulse generator has been designed based on a switchable capacitor array and a SiC MOSFET switching array. The proposed pulse generator has one output channel with an adjustable pulse width from 100 ns to 100 µs, an amplitude range from 0 kV to 2 kV, a repetition rate less than 1.2 kHz and a voltage drop less than 5%. The mechanism of the stacked switches circuit was investigated, in connection with a switchable capacitor array. The introduction of a switchable capacitor array extends the pulse width from nanosecond scale and microsecond scale compared with other similar design methods. The pulse generator has been designed in simulation and implemented in experiment. The developed pulse generator provides a convenient and economical tool for the further studies of the unique biological effects stimulated by different pulsed electric fields for tumor treatment. Full article
(This article belongs to the Section Bioelectronics)
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25 pages, 5807 KiB  
Article
Verification Plan Using Neural Algorithm Blockchain Smart Contract for Secure P2P Real Estate Transactions
by Jun-Ho Huh and Seong-Kyu Kim
Electronics 2020, 9(6), 1052; https://doi.org/10.3390/electronics9061052 - 26 Jun 2020
Cited by 27 | Viewed by 6954
Abstract
Blockchain and artificial intelligence are the most important keywords in the Fourth Industrial Revolution. This study sought to apply these core technologies to future validated algorithms that make real estate transactions secure to come up with an encryption algorithm. In addition, the real [...] Read more.
Blockchain and artificial intelligence are the most important keywords in the Fourth Industrial Revolution. This study sought to apply these core technologies to future validated algorithms that make real estate transactions secure to come up with an encryption algorithm. In addition, the real estate transaction is being paid a large fee by the middlemen, the real estate agent. Furthermore and recently, P2P (peer-to-peer) real estate exchange is used a lot. However, these P2P real estate exchanges also have problems that have not been identified by each other between landlords and tenants. In particular, a research model was established to compare and verify the PBFT (practical Byzantine fault tolerance) algorithm of Hyperledger through the blockchain agreement process. Subsequently, a process for verifying the real estate contract was established. Through VM (virtual machine) research methodology for the verification of blockchain real estate contracts, ElGamal communication was provided to prove quantum cryptography. We also automated lightweight encryption test verification tools and blockchain smart contract VM (virtual machine) models using artificial intelligence. Verification was performed through a reservation server and a monitoring server using a test verification tool for network-based lightweight security IoT (Internet of things) GW (gateway). It presents important ECP (elastic curve program) and elastic curve Qu-Vanstone (ECQV) models among the main functions of the blockchain smart contract, and it is equipped with quantum-based encryption algorithm. In addition, the necessary UML (unified modeling language) source code and performance data were calculated according to the actual experimental environment, and the average value for blockchain for administrative or government authorized assets—4000 TPS (transaction per second) were tested. In the future, we want to use this technology for real estate transactions. Full article
(This article belongs to the Special Issue Blockchain Based Electronic Healthcare Solution and Security)
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11 pages, 3100 KiB  
Article
Optimization Considerations for Short Channel Poly-Si 1T-DRAM
by Songyi Yoo, Woo-Kyung Sun and Hyungsoon Shin
Electronics 2020, 9(6), 1051; https://doi.org/10.3390/electronics9061051 - 25 Jun 2020
Cited by 2 | Viewed by 4189
Abstract
Capacitorless one-transistor dynamic random-access memory cells that use a polysilicon body (poly-Si 1T-DRAM) have been studied to overcome the scaling issues of conventional one-transistor one-capacitor dynamic random-access memory (1T-1C DRAM). Generally, when the gate length of a silicon-on-insulator (SOI) structure metal-oxide-silicon field-effect transistor [...] Read more.
Capacitorless one-transistor dynamic random-access memory cells that use a polysilicon body (poly-Si 1T-DRAM) have been studied to overcome the scaling issues of conventional one-transistor one-capacitor dynamic random-access memory (1T-1C DRAM). Generally, when the gate length of a silicon-on-insulator (SOI) structure metal-oxide-silicon field-effect transistor (MOSFET) is reduced, its body thickness is reduced in order to suppress the short-channel effects (SCEs). TCAD device simulations were used to investigate the transient performance differences between thin and thick-body poly-Si DRAMs to determine whether reduced body thickness is also appropriate for those devices. Analysis of the simulation results revealed that operating bias conditions are as important as body thickness in 1T-DRAM operation. Since a thick-body device has more trapped hole charge in its grain boundary (GB) than a thin-body device in both the “0” and “1” states, the transient performance of a thick-body device is better than a thin-body device regardless of the Write”1” drain voltage. We also determined that the SCEs in the memory cells can be improved by lowering the Write”1” drain voltage. We conclude that an optimization method for the body thickness and voltage conditions that considers both the cell’s SCEs and its transient performance is necessary for its development and application. Full article
(This article belongs to the Special Issue New CMOS Devices and Their Applications)
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27 pages, 4907 KiB  
Article
Hierarchical Multi-Blockchain Architecture for Scalable Internet of Things Environment
by Yustus Eko Oktian, Sang-Gon Lee and Hoon Jae Lee
Electronics 2020, 9(6), 1050; https://doi.org/10.3390/electronics9061050 - 25 Jun 2020
Cited by 26 | Viewed by 4289
Abstract
Many researchers challenge the possibility of using blockchain and smart contracts to disrupt the Internet of Things (IoT) architecture because of their security and decentralization guarantees. However, the state-of-the-art blockchain architecture is not scalable enough to satisfy the requirements of massive data traffics [...] Read more.
Many researchers challenge the possibility of using blockchain and smart contracts to disrupt the Internet of Things (IoT) architecture because of their security and decentralization guarantees. However, the state-of-the-art blockchain architecture is not scalable enough to satisfy the requirements of massive data traffics in the IoT environment. The main reason for this issue is one needs to choose the consensus trade-off between either coping with a high throughput or a high number of nodes. Consequently, this issue prevents the applicability of blockchain for IoT use cases. In this paper, we propose a scalable two-tiered hierarchical blockchain architecture for IoT. The first tier is a Core Engine, which is based on a Practical Byzantine Fault Tolerance (PBFT) consensus to cope with a high throughput, that supervises the underlying subordinate engines (sub-engines) as its second tier. This second tier comprises of the Payment, Compute, and Storage Engine, respectively. We can deploy multiple instances of these sub-engines as many as we need and as local as possible near to the IoT domains, where IoT devices reside, to cope with a high number of nodes. Furthermore, to further extend the scalability of the proposed architecture, we also provide additional scalability features on the Core Engine such as request aggregation, request prioritization, as well as sub-engine parallelism. We implement all of our engines and expose them to IoT applications through the Engine APIs. With these APIs, developers can build and run IoT applications in our architecture. Our evaluation results show that our proposed features on the Core Engine can indeed enhance the overall performance of our architecture. Moreover, based on our proof-of-concept IoT car rental application, we also show that the interoperability between sub-engines through the Core Engine is possible, even when the particular sub-engine is under sub-engine parallelism. Full article
(This article belongs to the Section Computer Science & Engineering)
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13 pages, 4737 KiB  
Article
On-Chip Terahertz Detector Designed with Inset-Feed Rectangular Patch Antenna and Catadioptric Lens
by Fan Zhao, Luhong Mao, Weilian Guo, Sheng Xie and Clarence Augustine T. H. Tee
Electronics 2020, 9(6), 1049; https://doi.org/10.3390/electronics9061049 - 24 Jun 2020
Cited by 7 | Viewed by 3550
Abstract
This study proposes an on-chip terahertz (THz) detector designed with on-chip inset-feed rectangular patch antenna and catadioptric lens. The detector incorporates a dual antenna and dual NMOSFET structure. Radiation efficiency of the antenna reached 89.4% with 6.89 dB gain by optimizing the antenna [...] Read more.
This study proposes an on-chip terahertz (THz) detector designed with on-chip inset-feed rectangular patch antenna and catadioptric lens. The detector incorporates a dual antenna and dual NMOSFET structure. Radiation efficiency of the antenna reached 89.4% with 6.89 dB gain by optimizing the antenna inset-feed and micro-strip line sizes. Simulated impedance was 85.55 − j19.81 Ω, and the impedance of the antenna with the ZEONEX horn-like catadioptric lens was 117.03 − j20.28 Ω. Maximum analyzed gain of two on-chip antennas with catadioptric lens was 17.14 dB resonating at 267 GHz. Maximum experimental gain of two on-chip patch antennas was 4.5 dB at 260 GHz, increasing to 10.67 dB at 250 GHz with the catadioptric lens. The proposed on-chip rectangular inset-feed patch antenna has a simple structure, compatible with CMOS processing and easily implemented. The horn-like catadioptric lens was integrated into the front end of the detector chip and hence is easily molded and manufactured, and it effectively reduced terahertz power absorption by the chip substrate. This greatly improved the detector responsivity and provided very high gain. Corresponding detector voltage responsivity with and without the lens was 95.67 kV/W with NEP = 12.8 pW/Hz0.5 at 250 GHz, and 19.2 kV/W with NEP = 67.2 pW/Hz0.5 at 260 GHz, respectively. Full article
(This article belongs to the Special Issue Terahertz Technology and Its Applications)
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12 pages, 2579 KiB  
Article
Woven Fabric Pattern Recognition and Classification Based on Deep Convolutional Neural Networks
by Muhammad Ather Iqbal Hussain, Babar Khan, Zhijie Wang and Shenyi Ding
Electronics 2020, 9(6), 1048; https://doi.org/10.3390/electronics9061048 - 24 Jun 2020
Cited by 57 | Viewed by 10737
Abstract
The weave pattern (texture) of woven fabric is considered to be an important factor of the design and production of high-quality fabric. Traditionally, the recognition of woven fabric has a lot of challenges due to its manual visual inspection. Moreover, the approaches based [...] Read more.
The weave pattern (texture) of woven fabric is considered to be an important factor of the design and production of high-quality fabric. Traditionally, the recognition of woven fabric has a lot of challenges due to its manual visual inspection. Moreover, the approaches based on early machine learning algorithms directly depend on handcrafted features, which are time-consuming and error-prone processes. Hence, an automated system is needed for classification of woven fabric to improve productivity. In this paper, we propose a deep learning model based on data augmentation and transfer learning approach for the classification and recognition of woven fabrics. The model uses the residual network (ResNet), where the fabric texture features are extracted and classified automatically in an end-to-end fashion. We evaluated the results of our model using evaluation metrics such as accuracy, balanced accuracy, and F1-score. The experimental results show that the proposed model is robust and achieves state-of-the-art accuracy even when the physical properties of the fabric are changed. We compared our results with other baseline approaches and a pretrained VGGNet deep learning model which showed that the proposed method achieved higher accuracy when rotational orientations in fabric and proper lighting effects were considered. Full article
(This article belongs to the Special Issue Computer Vision and Machine Learning in Human-Computer Interaction)
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20 pages, 2743 KiB  
Article
Near-Field Warping Sampling Scheme for Broad-Side Antenna Characterization
by Maria Antonia Maisto, Rocco Pierri and Raffaele Solimene
Electronics 2020, 9(6), 1047; https://doi.org/10.3390/electronics9061047 - 24 Jun 2020
Cited by 20 | Viewed by 3579
Abstract
In this paper the problem of sampling the field radiated by a planar source observed over a finite planar aperture located in the near-field is addressed. The problem is cast as the determination of the spatial measurement positions which allow us to discretize [...] Read more.
In this paper the problem of sampling the field radiated by a planar source observed over a finite planar aperture located in the near-field is addressed. The problem is cast as the determination of the spatial measurement positions which allow us to discretize the radiation problem so that the singular values of the radiation operator are well-approximated. More in detail, thanks to a suitably warping transformation of the observation variables, the kernel function of the relevant operator is approximated by a band-limited function and hence the sampling theorem applied to achieved discretization. It results in the sampling points having to be non-linearity arranged across the measurement aperture and their number can be considerably lowered as compared to more standard sampling approach. It is shown that the proposed sampling scheme works well for measurement apertures that are not too large as compared to the source’s size. As a consequence, the method appears better suited for broad-side large antenna whose radiated field is mainly concentrated in front of the antenna. A numerical analysis is included to check the theoretical findings and to study the trade-off between the field accuracy representation (over the measurement aperture) and the truncation error in the estimated far-field radiation pattern. Full article
(This article belongs to the Special Issue Photonic and Microwave Sensing Developments and Applications)
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23 pages, 8488 KiB  
Article
Efficient Implementation of Homomorphic and Fuzzy Transforms in Random-Projection Encryption Frameworks for Cancellable Face Recognition
by Abeer D. Algarni, Ghada M. El Banby, Naglaa F. Soliman, Fathi E. Abd El-Samie and Abdullah M. Iliyasu
Electronics 2020, 9(6), 1046; https://doi.org/10.3390/electronics9061046 - 24 Jun 2020
Cited by 23 | Viewed by 3321
Abstract
To circumvent problems associated with dependence on traditional security systems on passwords, Personal Identification Numbers (PINs) and tokens, modern security systems adopt biometric traits that are inimitable to each individual for identification and verification. This study presents two different frameworks for secure person [...] Read more.
To circumvent problems associated with dependence on traditional security systems on passwords, Personal Identification Numbers (PINs) and tokens, modern security systems adopt biometric traits that are inimitable to each individual for identification and verification. This study presents two different frameworks for secure person identification using cancellable face recognition (CFR) schemes. Exploiting its ability to guarantee irrevocability and rich diversity, both frameworks utilise Random Projection (RP) to encrypt the biometric traits. In the first framework, a hybrid structure combining Intuitionistic Fuzzy Logic (IFL) with RP is used to accomplish full distortion and encryption of the original biometric traits to be saved in the database, which helps to prevent unauthorised access of the biometric data. The framework involves transformation of spatial-domain greyscale pixel information to a fuzzy domain where the original biometric images are disfigured and further distorted via random projections that generate the final cancellable traits. In the second framework, cancellable biometric traits are similarly generated via homomorphic transforms that use random projections to encrypt the reflectance components of the biometric traits. Here, the use of reflectance properties is motivated by its ability to retain most image details, while the guarantee of the non-invertibility of the cancellable biometric traits supports the rationale behind our utilisation of another RP stage in both frameworks, since independent outcomes of both the IFL stage and the reflectance component of the homomorphic transform are not enough to recover the original biometric trait. Our CFR schemes are validated on different datasets that exhibit properties expected in actual application settings such as varying backgrounds, lightings, and motion. Outcomes in terms standard metrics, including structural similarity index metric (SSIM) and area under the receiver operating characteristic curve (AROC), suggest the efficacy of our proposed schemes across many applications that require person identification and verification. Full article
(This article belongs to the Special Issue Data Security)
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20 pages, 7833 KiB  
Article
Comprehensive Development of Dynamic Wireless Power Transfer System for Electric Vehicle
by Manuele Bertoluzzo, Mauro Di Monaco, Giuseppe Buja, Giuseppe Tomasso and Antonino Genovese
Electronics 2020, 9(6), 1045; https://doi.org/10.3390/electronics9061045 - 24 Jun 2020
Cited by 8 | Viewed by 3960
Abstract
This paper presents a comprehensive development of a dynamic wireless power transfer (WPT) system for the charge of the battery onboard an electric vehicle (EV). The development starts from the assessment of the electrical specifications of the dynamic WPT system, goes through the [...] Read more.
This paper presents a comprehensive development of a dynamic wireless power transfer (WPT) system for the charge of the battery onboard an electric vehicle (EV). The development starts from the assessment of the electrical specifications of the dynamic WPT system, goes through the design of its power stages, and concludes with its validation. In the design step, the structure of the coupling set, layout of the coils, configuration of the conversion stages and topology of the compensation networks are illustrated, as well as electrical sizing of the power stage components. In the validation step, the setup of a dynamic WPT system is described, and the results of experimental tests carried out with the pickup moving along the track are given. Full article
(This article belongs to the Special Issue Emerging Technologies for Wireless Power Transfer in Transportation)
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21 pages, 1642 KiB  
Article
A Wireless Body Sensor Network for Clinical Assessment of the Flexion-Relaxation Phenomenon
by Michele Paoletti, Alberto Belli, Lorenzo Palma, Massimo Vallasciani and Paola Pierleoni
Electronics 2020, 9(6), 1044; https://doi.org/10.3390/electronics9061044 - 24 Jun 2020
Cited by 5 | Viewed by 5457
Abstract
An accurate clinical assessment of the flexion-relaxation phenomenon on back muscles requires objective tools for the analysis of surface electromyography signals correlated with the real movement performed by the subject during the flexion-relaxation test. This paper deepens the evaluation of the flexion-relaxation phenomenon [...] Read more.
An accurate clinical assessment of the flexion-relaxation phenomenon on back muscles requires objective tools for the analysis of surface electromyography signals correlated with the real movement performed by the subject during the flexion-relaxation test. This paper deepens the evaluation of the flexion-relaxation phenomenon using a wireless body sensor network consisting of sEMG sensors in association with a wearable device that integrates accelerometer, gyroscope, and magnetometer. The raw data collected from the sensors during the flexion relaxation test are processed by an algorithm able to identify the phases of which the test is composed, provide an evaluation of the myoelectric activity and automatically detect the phenomenon presence/absence. The developed algorithm was used to process the data collected in an acquisition campaign conducted to evaluate the flexion-relaxation phenomenon on back muscles of subjects with and without Low Back Pain. The results have shown that the proposed method is significant for myoelectric silence detection and for clinical assessment of electromyography activity patterns. Full article
(This article belongs to the Special Issue Recent Advances in Motion Analysis)
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18 pages, 6868 KiB  
Article
Optimal Power Flow Incorporating FACTS Devices and Stochastic Wind Power Generation Using Krill Herd Algorithm
by Arsalan Abdollahi, Ali Asghar Ghadimi, Mohammad Reza Miveh, Fazel Mohammadi and Francisco Jurado
Electronics 2020, 9(6), 1043; https://doi.org/10.3390/electronics9061043 - 24 Jun 2020
Cited by 36 | Viewed by 3338
Abstract
This paper deals with investigating the Optimal Power Flow (OPF) solution of power systems considering Flexible AC Transmission Systems (FACTS) devices and wind power generation under uncertainty. The Krill Herd Algorithm (KHA), as a new meta-heuristic approach, is employed to cope with the [...] Read more.
This paper deals with investigating the Optimal Power Flow (OPF) solution of power systems considering Flexible AC Transmission Systems (FACTS) devices and wind power generation under uncertainty. The Krill Herd Algorithm (KHA), as a new meta-heuristic approach, is employed to cope with the OPF problem of power systems, incorporating FACTS devices and stochastic wind power generation. The wind power uncertainty is included in the optimization problem using Weibull probability density function modeling to determine the optimal values of decision variables. Various objective functions, including minimization of fuel cost, active power losses across transmission lines, emission, and Combined Economic and Environmental Costs (CEEC), are separately formulated to solve the OPF considering FACTS devices and stochastic wind power generation. The effectiveness of the KHA approach is investigated on modified IEEE-30 bus and IEEE-57 bus test systems and compared with other conventional methods available in the literature. Full article
(This article belongs to the Special Issue Emerging Technologies in Power Systems)
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14 pages, 9663 KiB  
Article
A 920-MHz Dual-Mode Receiver with Energy Harvesting for UHF RFID Tag and IoT
by Peiqing Han, Zhaofeng Zhang, Yajun Xia and Niansong Mei
Electronics 2020, 9(6), 1042; https://doi.org/10.3390/electronics9061042 - 24 Jun 2020
Cited by 9 | Viewed by 5054
Abstract
A low-power dual-mode receiver is presented for ultra-high-frequency (UHF) radio frequency identification (RFID) systems. The reconfigurable architecture of the tag is proposed to be compatible with low-power and high-sensitivity operating modes. The read range of RFID system and the lifetime of the tag [...] Read more.
A low-power dual-mode receiver is presented for ultra-high-frequency (UHF) radio frequency identification (RFID) systems. The reconfigurable architecture of the tag is proposed to be compatible with low-power and high-sensitivity operating modes. The read range of RFID system and the lifetime of the tag are increased by photovoltaic, thermoelectric and RF energy-harvesting topology. The receiver is implemented in a 0.18-μm standard CMOS process and occupies an active area of 0.65 mm × 0.7 mm. For low-power mode, the tag is powered by the rectifier and the sensitivity is −18 dBm. For high-sensitivity mode, the maximum PCE of the fully on-chip energy harvester is 46.5% with over 1-μW output power and the sensitivity is −40 dBm with 880 nW power consumption under the supply voltage of 0.8 V. Full article
(This article belongs to the Special Issue Ultra-Low Power Circuits Design)
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20 pages, 1431 KiB  
Article
Nested High Order Sliding Mode Controller with Back-EMF Sliding Mode Observer for a Brushless Direct Current Motor
by Alma Y. Alanis, Gustavo Munoz-Gomez and Jorge Rivera
Electronics 2020, 9(6), 1041; https://doi.org/10.3390/electronics9061041 - 24 Jun 2020
Cited by 8 | Viewed by 3709
Abstract
This work presents a nested super-twisting second-order sliding mode speed controller for a brushless direct current motor with a high order sliding mode observer used for back electromotive force (back-EMF) estimation. Due to the trapezoidal nature of the back-EMF, a modified Park transformation [...] Read more.
This work presents a nested super-twisting second-order sliding mode speed controller for a brushless direct current motor with a high order sliding mode observer used for back electromotive force (back-EMF) estimation. Due to the trapezoidal nature of the back-EMF, a modified Park transformation is used in order to achieve proper field orientation. Such transformation requires information from the back-EMF that is not accessible. A second-order sliding mode observer is used to estimate the back electromotive forces needed in the modified transformation. Sliding mode control is known to be robust to matched uncertain disturbances and parametric variations but it is prone to unmatched perturbations that affect the performance of the system. A nested scheme is used to improve the response of the controller in presence of unmatched disturbances. Simulations performed under similar conditions to real-time experimentation show a good regulation of the rotor speed in terms of transient and steady-state responses along with a reduced torque ripple. Full article
(This article belongs to the Special Issue Recent Issues on Motors and Motor Drives)
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25 pages, 33441 KiB  
Article
FlexAlign: An Accurate and Fast Algorithm for Movie Alignment in Cryo-Electron Microscopy
by David Střelák, Jiří Filipovič, Amaya Jiménez-Moreno, Jose María Carazo and Carlos Óscar Sánchez Sorzano
Electronics 2020, 9(6), 1040; https://doi.org/10.3390/electronics9061040 - 23 Jun 2020
Cited by 5 | Viewed by 5096
Abstract
Cryogenic Electron Microscopy (Cryo-EM) has been established as one of the key players in Structural Biology. It can reconstruct a 3D model of the sample at the near-atomic resolution, which led to a Method of the year award by Nature, and the Nobel [...] Read more.
Cryogenic Electron Microscopy (Cryo-EM) has been established as one of the key players in Structural Biology. It can reconstruct a 3D model of the sample at the near-atomic resolution, which led to a Method of the year award by Nature, and the Nobel Prize in 2017. With the growing number of facilities, faster microscopes, and new imaging techniques, new algorithms are needed to process the so-called movies data produced by the microscopes in real-time, while preserving a high resolution and maximum of additional information. In this article, we present a new algorithm used for movie alignment, called FlexAlign. FlexAlign is able to correctly compensate for the shift produced during the movie acquisition on-the-fly, using the current generation of hardware. The algorithm performs a global and elastic local registration of the movie frames using Cross-Correlation and B-spline interpolation for high precision. We show that our execution time is compatible with real-time correction and that we preserve the high-resolution information up to high frequency. Full article
(This article belongs to the Special Issue FPGA/GPU Acceleration of Biomedical Engineering Applications)
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12 pages, 3304 KiB  
Article
A Context-Aware IoT and Deep-Learning-Based Smart Classroom for Controlling Demand and Supply of Power Load
by Prabesh Paudel, Sangkyoon Kim, Soonyoung Park and Kyoung-Ho Choi
Electronics 2020, 9(6), 1039; https://doi.org/10.3390/electronics9061039 - 23 Jun 2020
Cited by 13 | Viewed by 4676
Abstract
With the demand for clean energy increasing, novel research is presented in this paper on providing sustainable, clean energy for a university campus. The Internet of Things (IoT) is now a leading factor in saving energy. With added deep learning for action recognition, [...] Read more.
With the demand for clean energy increasing, novel research is presented in this paper on providing sustainable, clean energy for a university campus. The Internet of Things (IoT) is now a leading factor in saving energy. With added deep learning for action recognition, IoT sensors implemented in real-time appliances monitor and control the extra usage of energy in buildings. This gives an extra edge on digitizing energy usage and, ultimately, reducing the power load in the electric grid. Here, we present a novel proposal through context-aware architecture for energy saving in classrooms, combining Internet of Things (IoT) sensors and video action recognition. Using this method, we can save a significant amount of energy usage in buildings. Full article
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23 pages, 2965 KiB  
Article
Boosted Trees Algorithm as Reliable Spectrum Sensing Scheme in the Presence of Malicious Users
by Noor Gul, Muhammad Sajjad Khan, Su Min Kim, Junsu Kim, Atif Elahi and Zafar Khalil
Electronics 2020, 9(6), 1038; https://doi.org/10.3390/electronics9061038 - 23 Jun 2020
Cited by 12 | Viewed by 2928
Abstract
Cooperative spectrum sensing (CSS) has the ability to accurately identify the activities of the primary users (PUs). As the secondary users’ (SUs) sensing performance is disturbed in the fading and shadowing environment, therefore the CSS is a suitable choice to achieve better sensing [...] Read more.
Cooperative spectrum sensing (CSS) has the ability to accurately identify the activities of the primary users (PUs). As the secondary users’ (SUs) sensing performance is disturbed in the fading and shadowing environment, therefore the CSS is a suitable choice to achieve better sensing results compared to individual sensing. One of the problems in the CSS occurs due to the participation of malicious users (MUs) that report false sensing data to the fusion center (FC) to misguide the FC’s decision about the PUs’ activity. Out of the different categories of MUs, Always Yes (AY), Always No (AN), Always Opposite (AO) and Random Opposite (RO) are of high interest these days in the literature. Recently, high sensing performance for the CSS can be achieved using machine learning techniques. In this paper, boosted trees algorithm (BTA) has been proposed for obtaining reliable identification of the PU channel, where the SUs can access the PU channel opportunistically with minimum disturbances to the licensee. The proposed BTA mitigates the spectrum sensing data falsification (SSDF) effects of the AY, AN, AO and RO categories of the MUs. BTA is an ensemble method for solving spectrum sensing problems using different classifiers. It boosts the performance of some weak classifiers in the combination by giving higher weights to the weak classifiers’ sensing decisions. Simulation results verify the performance improvement by the proposed algorithm compared to the existing techniques such as genetic algorithm soft decision fusion (GASDF), particle swarm optimization soft decision fusion (PSOSDF), maximum gain combination soft decision fusion (MGCSDF) and count hard decision fusion (CHDF). The experimental setup is conducted at different levels of the signal-to-noise ratios (SNRs), total number of cooperative users and sensing samples that show minimum error probability results for the proposed scheme. Full article
(This article belongs to the Special Issue Cyber Security for Internet of Things)
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21 pages, 7472 KiB  
Article
Study of NVIS Channel for USN Protocol Definition in Antarctica
by Josep M. Maso, Joaquim Porte, Joan L. Pijoan and David Badia
Electronics 2020, 9(6), 1037; https://doi.org/10.3390/electronics9061037 - 23 Jun 2020
Cited by 3 | Viewed by 3303
Abstract
Every year, the number of ubiquitous sensor networks (USN) is increasing and the need for remote USN communications is emerging in some scenarios. As an alternative to satellite communications, more interests are focused on high frequencies (HF) communications as a low-cost option to [...] Read more.
Every year, the number of ubiquitous sensor networks (USN) is increasing and the need for remote USN communications is emerging in some scenarios. As an alternative to satellite communications, more interests are focused on high frequencies (HF) communications as a low-cost option to reach links of more than 250 km without a line of sight. The HF standards are designed for generic communication channels being not robust for near vertical incidence skywave (NVIS) USN. In this article, we propose a new protocol for USN in remote places based on NVIS communications. For that purpose, we study the main characteristics of the NVIS channel with the presence of groundwaves, particularly in Antarctica. We analyze the availability of the channel, the height of the layers, the delay spread, and the Doppler spread. On the basis of the results obtained, we propose two protocols based on an OFDM (orthogonal frequency division multiplexing) modulation depending on the presence of the groundwave at the receiver. Finally, we make a simulation of the two OFDM configurations and we compare it with real tested standard modulations. The results show a better performance of the new protocol compared to the current HF standards. Full article
(This article belongs to the Special Issue Ubiquitous Sensor Networks)
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15 pages, 2590 KiB  
Article
Design and Evaluation of Cell Interaction Based Vedic Multiplier Using Quantum-Dot Cellular Automata
by Nuriddin Safoev and Jun-Cheol Jeon
Electronics 2020, 9(6), 1036; https://doi.org/10.3390/electronics9061036 - 23 Jun 2020
Cited by 36 | Viewed by 5130
Abstract
A multiplier is one of the main units for digital signal processing and communication systems. In this paper, a high speed and low complexity multiplier is designed on the basis of quantum-dot cellular automata (QCA), which is considered promising nanotechnology. We focus on [...] Read more.
A multiplier is one of the main units for digital signal processing and communication systems. In this paper, a high speed and low complexity multiplier is designed on the basis of quantum-dot cellular automata (QCA), which is considered promising nanotechnology. We focus on Vedic multiplier architectures according to Vedic mathematics from ancient Indian sculptures. In fact, an adder is an important block in the design of almost all types of multipliers and a ripple carry adder is used to design simple multiplier implementations. However, a high-speed multi-bit multiplier requires high-speed adder owing to carry propagation. Cell-interaction-based QCA adders have better improvements over conventional majority-gate-based adders. Therefore, a two-bit Vedic multiplier is proposed in QCA and it is used to implement a four-bit form of the multiplier. The proposed architecture has a lower cell count and area compared to other existing structures. Moreover, simulation results demonstrate that the proposed design is sustainable and can be used to realize complex circuit designs for QCA communication networks. Full article
(This article belongs to the Section Computer Science & Engineering)
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13 pages, 7882 KiB  
Article
Comparative Performance Evaluation of Modern Heterogeneous High-Performance Computing Systems CPUs
by Aleksei Sorokin, Sergey Malkovsky, Georgiy Tsoy, Alexander Zatsarinnyy and Konstantin Volovich
Electronics 2020, 9(6), 1035; https://doi.org/10.3390/electronics9061035 - 23 Jun 2020
Cited by 4 | Viewed by 3841
Abstract
The study presents a comparison of computing systems based on IBM POWER8, IBM POWER9, and Intel Xeon Platinum 8160 processors running parallel applications. Memory subsystem bandwidth was studied, parallel programming technologies were compared, and the operating modes and capabilities of simultaneous multithreading technology [...] Read more.
The study presents a comparison of computing systems based on IBM POWER8, IBM POWER9, and Intel Xeon Platinum 8160 processors running parallel applications. Memory subsystem bandwidth was studied, parallel programming technologies were compared, and the operating modes and capabilities of simultaneous multithreading technology were analyzed. Performance analysis for the studied computing systems running parallel applications based on the OpenMP and MPI technologies was carried out by using the NAS Parallel Benchmarks. An assessment of the results obtained during experimental calculations led to the conclusion that IBM POWER8 and Intel Xeon Platinum 8160 systems have almost the same maximum memory bandwidth, but require a different number of threads for efficient utilization. The IBM POWER9 system has the highest maximum bandwidth, which can be attributed to the large number of memory channels per socket. Based on the results of numerical experiments, recommendations are given on how the hardware of a similar grade can be utilized to solve various scientific problems, including recommendations on optimal processor architecture choice for leveraging the operation of high-performance hybrid computing platforms. Full article
(This article belongs to the Special Issue High-Performance Computer Architectures and Applications)
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13 pages, 1309 KiB  
Article
Distance Special Education Delivery by Social Robots
by Chris Lytridis, Christos Bazinas, George Sidiropoulos, George A. Papakostas, Vassilis G. Kaburlasos, Vasiliki-Aliki Nikopoulou, Vasiliki Holeva and Athanasios Evangeliou
Electronics 2020, 9(6), 1034; https://doi.org/10.3390/electronics9061034 - 23 Jun 2020
Cited by 20 | Viewed by 4250
Abstract
The outbreak of the Severe Acute Respiratory Syndrome coronavirus (SARS-CoV2) has resulted in a significant disruption of almost all aspects of everyday life. Several governments around the world have adopted emergency actions to reduce spreading of the virus, which included suspension of non-essential [...] Read more.
The outbreak of the Severe Acute Respiratory Syndrome coronavirus (SARS-CoV2) has resulted in a significant disruption of almost all aspects of everyday life. Several governments around the world have adopted emergency actions to reduce spreading of the virus, which included suspension of non-essential activities and the implementation of social distancing practices. In our case, governmental measures have resulted in the suspension of our experimental protocol for testing the effectiveness of robot-based treatment of children diagnosed with Autism Spectrum Disorder (ASD) compared to conventional human (therapist)-based treatment. These circumstances led to an investigation of the potential of tele-consulting. This paper describes alternatives to implement synchronous and asynchronous therapeutic sessions for children already participating in the protocol, in order to reduce the negative effects of the strict cessation of the in-person sessions. The usefulness of our approach was assessed by recording the children’s and the parent’s satisfaction via questionnaires. In addition, we compare satisfaction between the synchronous and asynchronous sessions. The results show that the approach has been very satisfactory and useful for both children and parents, and that this was especially the case for the robot-based material. Full article
(This article belongs to the Special Issue Applications and Trends in Social Robotics)
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20 pages, 2233 KiB  
Article
Exploring Malware Behavior of Webpages Using Machine Learning Technique: An Empirical Study
by Alhanoof Faiz Alwaghid and Nurul I. Sarkar
Electronics 2020, 9(6), 1033; https://doi.org/10.3390/electronics9061033 - 23 Jun 2020
Cited by 4 | Viewed by 3474
Abstract
Malware is one of the most common security threats experienced by a user when browsing webpages. A good understanding of the features of webpages (e.g., internet protocol, port, URL, Google index, and page rank) is required to analyze and mitigate the behavior of [...] Read more.
Malware is one of the most common security threats experienced by a user when browsing webpages. A good understanding of the features of webpages (e.g., internet protocol, port, URL, Google index, and page rank) is required to analyze and mitigate the behavior of malware in webpages. This main objective of this paper is to analyze the key features of webpages and to mitigate the behavior of malware in webpages. To this end, we conducted an empirical study to identify the features that are most vulnerable to malware attacks and its results are reported. To improve the feature selection accuracy, a machine learning technique called bagging is employed using the Weka program. To analyze these behaviors, phishing and botnet data were obtained from the University of California Irvine machine learning repository. We validate our research findings by applying honeypot infrastructure using the Modern Honeypot Network (MHN) setup in a Linode Server. As the data suffer from high variance in terms of the type of data in each row, bagging is chosen because it can classify binary classes, date classes, missing values, nominal classes, numeric classes, unary classes and empty classes. As a base classifier of bagging, random tree was applied because it can handle similar types of data such as bagging, but better than other classifiers because it is faster and more accurate. Random tree had 88.22% test accuracy with the lowest run time (0.2 sec) and a receiver operating characteristic curve of 0.946. Results show that all features in the botnet dataset are equally important to identify the malicious behavior, as all scored more than 97%, with the exception of TCP and UDP. The accuracy of phishing and botnet datasets is more than 89% on average in both cross validation and test analysis. Recommendations are made for the best practice that can assist in future malware identification. Full article
(This article belongs to the Section Computer Science & Engineering)
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15 pages, 8055 KiB  
Article
An Area-Efficient and Programmable 4 × 25-to-28.9 Gb/s Optical Receiver with DCOC in 0.13 µm SiGe BiCMOS
by Haojie Xu, Jiarui Liu, Zhiyu Wang, Min Zhou, Jiongjiong Mo and Faxin Yu
Electronics 2020, 9(6), 1032; https://doi.org/10.3390/electronics9061032 - 22 Jun 2020
Viewed by 3091
Abstract
In this paper, we present an area-efficient noise-optimized programmable 4 × 25-to-28.9 Gb/s optical receiver. Both high- and low-power modes are available for the receiver to meet different requirements. Emitter degeneration provides the input transimpedance amplifier (TIA) stage with improved stability. The noise [...] Read more.
In this paper, we present an area-efficient noise-optimized programmable 4 × 25-to-28.9 Gb/s optical receiver. Both high- and low-power modes are available for the receiver to meet different requirements. Emitter degeneration provides the input transimpedance amplifier (TIA) stage with improved stability. The noise of the TIA with emitter degeneration is analyzed, and an improved noise optimization method for the TIA is proposed. A sink current source with emitter degeneration in a DC offset cancellation (DCOC) loop reduces the noise introduced by the DCOC circuit. Moreover, with parasitic capacitor utilization in the DCOC loop and capacitive emitter degeneration in the variable-gain amplifier (VGA) stage, the chip area is minimized. Fabricated in a 0.13 µm SiGe BiCMOS technology, the receiver achieved a small area of 0.54 mm2 per lane. The measured bit error rate (BER) is 10−12 with input signal varying from 110 μApp to 1150 μApp. The one-lane power dissipation values in the low-power and high-power modes are 84.97 mW and 123.75 mW, respectively. Full article
(This article belongs to the Special Issue Advanced Integrated Circuits Technology)
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13 pages, 1507 KiB  
Article
A Novel High Gain Wideband MIMO Antenna for 5G Millimeter Wave Applications
by Daniyal Ali Sehrai, Mujeeb Abdullah, Ahsan Altaf, Saad Hassan Kiani, Fazal Muhammad, Muhammad Tufail, Muhammad Irfan, Adam Glowacz and Saifur Rahman
Electronics 2020, 9(6), 1031; https://doi.org/10.3390/electronics9061031 - 22 Jun 2020
Cited by 134 | Viewed by 7538
Abstract
A compact tree shape planar quad element Multiple Input Multiple Output (MIMO) antenna bearing a wide bandwidth for 5G communication operating in the millimeter-wave spectrum is proposed. The radiating element of the proposed design contains four different arcs to achieve the wide bandwidth [...] Read more.
A compact tree shape planar quad element Multiple Input Multiple Output (MIMO) antenna bearing a wide bandwidth for 5G communication operating in the millimeter-wave spectrum is proposed. The radiating element of the proposed design contains four different arcs to achieve the wide bandwidth response. Each radiating element is backed by a 1.57 mm thicker Rogers-5880 substrate material, having a loss tangent and relative dielectric constant of 0.0009 and 2.2, respectively. The measured impedance bandwidth of the proposed quad element MIMO antenna system based on 10 dB criterion is from 23 GHz to 40 GHz with a port isolation of greater than 20 dB. The measured radiation patterns are presented at 28 GHz, 33 GHz and 38 GHz with a maximum total gain of 10.58, 8.87 and 11.45 dB, respectively. The high gain of the proposed antenna further helps to overcome the atmospheric attenuations faced by the higher frequencies. In addition, the measured total efficiency of the proposed MIMO antenna is observed above 70% for the millimeter wave frequencies. Furthermore, the MIMO key performance metrics such as Mean Effective Gain (MEG) and Envelope Correlation Coefficient (ECC) are analyzed and found to conform to the required standard of MEG < 3 dB and ECC < 0.5. A prototype of the proposed quad element MIMO antenna system is fabricated and measured. The experimental results validate the simulation design process conducted with Computer Simulation Technology (CST) software. Full article
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25 pages, 723 KiB  
Review
State-of-the-Art Artificial Intelligence Techniques for Distributed Smart Grids: A Review
by Syed Saqib Ali and Bong Jun Choi
Electronics 2020, 9(6), 1030; https://doi.org/10.3390/electronics9061030 - 22 Jun 2020
Cited by 178 | Viewed by 16295
Abstract
The power system worldwide is going through a revolutionary transformation due to the integration with various distributed components, including advanced metering infrastructure, communication infrastructure, distributed energy resources, and electric vehicles, to improve the reliability, energy efficiency, management, and security of the future power [...] Read more.
The power system worldwide is going through a revolutionary transformation due to the integration with various distributed components, including advanced metering infrastructure, communication infrastructure, distributed energy resources, and electric vehicles, to improve the reliability, energy efficiency, management, and security of the future power system. These components are becoming more tightly integrated with IoT. They are expected to generate a vast amount of data to support various applications in the smart grid, such as distributed energy management, generation forecasting, grid health monitoring, fault detection, home energy management, etc. With these new components and information, artificial intelligence techniques can be applied to automate and further improve the performance of the smart grid. In this paper, we provide a comprehensive review of the state-of-the-art artificial intelligence techniques to support various applications in a distributed smart grid. In particular, we discuss how artificial techniques are applied to support the integration of renewable energy resources, the integration of energy storage systems, demand response, management of the grid and home energy, and security. As the smart grid involves various actors, such as energy produces, markets, and consumers, we also discuss how artificial intelligence and market liberalization can potentially help to increase the overall social welfare of the grid. Finally, we provide further research challenges for large-scale integration and orchestration of automated distributed devices to realize a truly smart grid. Full article
(This article belongs to the Special Issue Integration of Distributed Intelligent Energy Grid)
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24 pages, 5982 KiB  
Review
Challenges and Applications of Emerging Nonvolatile Memory Devices
by Writam Banerjee
Electronics 2020, 9(6), 1029; https://doi.org/10.3390/electronics9061029 - 22 Jun 2020
Cited by 189 | Viewed by 16882
Abstract
Emerging nonvolatile memory (eNVM) devices are pushing the limits of emerging applications beyond the scope of silicon-based complementary metal oxide semiconductors (CMOS). Among several alternatives, phase change memory, spin-transfer torque random access memory, and resistive random-access memory (RRAM) are major emerging technologies. This [...] Read more.
Emerging nonvolatile memory (eNVM) devices are pushing the limits of emerging applications beyond the scope of silicon-based complementary metal oxide semiconductors (CMOS). Among several alternatives, phase change memory, spin-transfer torque random access memory, and resistive random-access memory (RRAM) are major emerging technologies. This review explains all varieties of prototype and eNVM devices, their challenges, and their applications. A performance comparison shows that it is difficult to achieve a “universal memory” which can fulfill all requirements. Compared to other emerging alternative devices, RRAM technology is showing promise with its highly scalable, cost-effective, simple two-terminal structure, low-voltage and ultra-low-power operation capabilities, high-speed switching with high-endurance, long retention, and the possibility of three-dimensional integration for high-density applications. More precisely, this review explains the journey and device engineering of RRAM with various architectures. The challenges in different prototype and eNVM devices is disused with the conventional and novel application areas. Compare to other technologies, RRAM is the most promising approach which can be applicable as high-density memory, storage class memory, neuromorphic computing, and also in hardware security. In the post-CMOS era, a more efficient, intelligent, and secure computing system is possible to design with the help of eNVM devices. Full article
(This article belongs to the Special Issue Challenges and Applications of Non-volatile Memory)
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21 pages, 9751 KiB  
Article
Categorization of Green Spaces for a Sustainable Environment and Smart City Architecture by Utilizing Big Data
by Qi Liu, Hidayat Ullah, Wanggen Wan, Zhangyou Peng, Li Hou, Sanam Shahla Rizvi, Saqib Ali Haidery, Tong Qu and A. A. M. Muzahid
Electronics 2020, 9(6), 1028; https://doi.org/10.3390/electronics9061028 - 22 Jun 2020
Cited by 18 | Viewed by 4666
Abstract
Urban green spaces promote outdoor activities and social interaction, which make a significant contribution to the health and well-being of residents. This study presents an approach that focuses on the real spatial and temporal behavior of park visitors in different categories of green [...] Read more.
Urban green spaces promote outdoor activities and social interaction, which make a significant contribution to the health and well-being of residents. This study presents an approach that focuses on the real spatial and temporal behavior of park visitors in different categories of green parks. We used the large dataset available from the Chinese micro-blog Sina Weibo (often simply referred to as “Weibo”) to analyze data samples, in order to describe the behavioral patterns of millions of people with access to green spaces. We select Shanghai as a case study because urban residential segregation has already taken place, which was expected to be followed by concerns of environmental sustainability. In this research, we utilized social media check-in data to measure and compare the number of visitations to different kinds of green parks. Furthermore, we divided the green spaces into different categories according to their characteristics, and our main findings were: (1) the most popular category based upon the check-in data; (2) changes in the number of visitors according to the time of day; (3) seasonal impacts on behavior in public in relation to the different categories of parks; and (4) gender-based differences. To the best of our knowledge, this is the first study carried out in Shanghai utilizing Weibo data to focus upon the categorization of green space. It is also the first to offer recommendations for planners regarding the type of facilities they should provide to residents in green spaces, and regarding the sustainability of urban environments and smart city architecture. Full article
(This article belongs to the Special Issue Transforming Future Cities: Smart City)
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19 pages, 1603 KiB  
Article
Sizing CMOS Amplifiers by PSO and MOL to Improve DC Operating Point Conditions
by Esteban Tlelo-Cuautle, Martín Alejandro Valencia-Ponce and Luis Gerardo de la Fraga
Electronics 2020, 9(6), 1027; https://doi.org/10.3390/electronics9061027 - 22 Jun 2020
Cited by 23 | Viewed by 3823
Abstract
The sizes of the metal-oxide-semiconductor (MOS) transistors in an operational amplifier must guarantee strong direct current operating point (DCOP) conditions. This paper shows the usefulness of two population-based optimization algorithms to size transistors, namely—particle swarm optimization (PSO) and many optimizing liaisons (MOL). Both [...] Read more.
The sizes of the metal-oxide-semiconductor (MOS) transistors in an operational amplifier must guarantee strong direct current operating point (DCOP) conditions. This paper shows the usefulness of two population-based optimization algorithms to size transistors, namely—particle swarm optimization (PSO) and many optimizing liaisons (MOL). Both optimization algorithms link the circuit simulator SPICE to measure electrical characteristics. However, SPICE provides an output-file indicating that a transistor is in strong inversion but the DCOP can be in the limit, and it can switch to a different condition. In this manner, we highlight the application of PSO and MOL to size operational transconductance amplifiers (OTAs), which DCOP conditions are improved by the introduction of a procedure that handles constraints to ensure that the transistors are in the appropriate DCOP. The Miller and RFC-OTA are the cases of study, and their sizing is performed using UMC 180 nm CMOS technology. In both OTAs, the objective function is the maximization of the gain-bandwidth product under the main constraint of guaranteeing DCOPs to improve two figures of merit and to provide robustness to Monte Carlo simulations and PVT variations. Full article
(This article belongs to the Section Circuit and Signal Processing)
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