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  Subjects -> ELECTRONICS (Total: 188 journals)
Showing 1 - 200 of 277 Journals sorted alphabetically
Acta Electronica Malaysia     Open Access  
Advances in Electrical and Electronic Engineering     Open Access   (Followers: 7)
Advances in Electronics     Open Access   (Followers: 94)
Advances in Magnetic and Optical Resonance     Full-text available via subscription   (Followers: 8)
Advances in Power Electronics     Open Access   (Followers: 39)
Advancing Microelectronics     Hybrid Journal  
Aerospace and Electronic Systems, IEEE Transactions on     Hybrid Journal   (Followers: 344)
American Journal of Electrical and Electronic Engineering     Open Access   (Followers: 26)
Annals of Telecommunications     Hybrid Journal   (Followers: 9)
APSIPA Transactions on Signal and Information Processing     Open Access   (Followers: 9)
Archives of Electrical Engineering     Open Access   (Followers: 14)
Autonomous Mental Development, IEEE Transactions on     Hybrid Journal   (Followers: 8)
Bell Labs Technical Journal     Hybrid Journal   (Followers: 30)
Bioelectronics in Medicine     Hybrid Journal  
Biomedical Engineering, IEEE Reviews in     Full-text available via subscription   (Followers: 21)
Biomedical Engineering, IEEE Transactions on     Hybrid Journal   (Followers: 38)
Biomedical Instrumentation & Technology     Hybrid Journal   (Followers: 6)
Broadcasting, IEEE Transactions on     Hybrid Journal   (Followers: 13)
BULLETIN of National Technical University of Ukraine. Series RADIOTECHNIQUE. RADIOAPPARATUS BUILDING     Open Access   (Followers: 1)
Bulletin of the Polish Academy of Sciences : Technical Sciences     Open Access   (Followers: 1)
Canadian Journal of Remote Sensing     Full-text available via subscription   (Followers: 47)
China Communications     Full-text available via subscription   (Followers: 9)
Chinese Journal of Electronics     Hybrid Journal  
Circuits and Systems     Open Access   (Followers: 15)
Consumer Electronics Times     Open Access   (Followers: 5)
Control Systems     Hybrid Journal   (Followers: 304)
ECTI Transactions on Computer and Information Technology (ECTI-CIT)     Open Access  
ECTI Transactions on Electrical Engineering, Electronics, and Communications     Open Access   (Followers: 1)
Edu Elektrika Journal     Open Access   (Followers: 1)
Electrica     Open Access  
Electronic Design     Partially Free   (Followers: 123)
Electronic Markets     Hybrid Journal   (Followers: 7)
Electronic Materials Letters     Hybrid Journal   (Followers: 4)
Electronics     Open Access   (Followers: 103)
Electronics and Communications in Japan     Hybrid Journal   (Followers: 10)
Electronics For You     Partially Free   (Followers: 102)
Electronics Letters     Hybrid Journal   (Followers: 26)
Elkha : Jurnal Teknik Elektro     Open Access  
Embedded Systems Letters, IEEE     Hybrid Journal   (Followers: 55)
Energy Harvesting and Systems     Hybrid Journal   (Followers: 4)
Energy Storage Materials     Full-text available via subscription   (Followers: 3)
EPJ Quantum Technology     Open Access   (Followers: 1)
EURASIP Journal on Embedded Systems     Open Access   (Followers: 11)
Facta Universitatis, Series : Electronics and Energetics     Open Access  
Foundations and Trends® in Communications and Information Theory     Full-text available via subscription   (Followers: 6)
Foundations and Trends® in Signal Processing     Full-text available via subscription   (Followers: 10)
Frequenz     Hybrid Journal   (Followers: 1)
Frontiers of Optoelectronics     Hybrid Journal   (Followers: 1)
Geoscience and Remote Sensing, IEEE Transactions on     Hybrid Journal   (Followers: 207)
Haptics, IEEE Transactions on     Hybrid Journal   (Followers: 4)
IACR Transactions on Symmetric Cryptology     Open Access  
IEEE Antennas and Propagation Magazine     Hybrid Journal   (Followers: 100)
IEEE Antennas and Wireless Propagation Letters     Hybrid Journal   (Followers: 81)
IEEE Journal of Emerging and Selected Topics in Power Electronics     Hybrid Journal   (Followers: 51)
IEEE Journal of the Electron Devices Society     Open Access   (Followers: 9)
IEEE Journal on Exploratory Solid-State Computational Devices and Circuits     Hybrid Journal   (Followers: 1)
IEEE Power Electronics Magazine     Full-text available via subscription   (Followers: 75)
IEEE Transactions on Antennas and Propagation     Full-text available via subscription   (Followers: 73)
IEEE Transactions on Automatic Control     Hybrid Journal   (Followers: 58)
IEEE Transactions on Circuits and Systems for Video Technology     Hybrid Journal   (Followers: 26)
IEEE Transactions on Consumer Electronics     Hybrid Journal   (Followers: 44)
IEEE Transactions on Electron Devices     Hybrid Journal   (Followers: 19)
IEEE Transactions on Information Theory     Hybrid Journal   (Followers: 26)
IEEE Transactions on Power Electronics     Hybrid Journal   (Followers: 78)
IEEE Transactions on Signal and Information Processing over Networks     Full-text available via subscription   (Followers: 12)
IEICE - Transactions on Electronics     Full-text available via subscription   (Followers: 12)
IEICE - Transactions on Information and Systems     Full-text available via subscription   (Followers: 5)
IET Cyber-Physical Systems : Theory & Applications     Open Access   (Followers: 1)
IET Energy Systems Integration     Open Access  
IET Microwaves, Antennas & Propagation     Hybrid Journal   (Followers: 35)
IET Nanodielectrics     Open Access  
IET Power Electronics     Hybrid Journal   (Followers: 57)
IET Smart Grid     Open Access  
IET Wireless Sensor Systems     Hybrid Journal   (Followers: 18)
IETE Journal of Education     Open Access   (Followers: 4)
IETE Journal of Research     Open Access   (Followers: 11)
IETE Technical Review     Open Access   (Followers: 13)
IJEIS (Indonesian Journal of Electronics and Instrumentation Systems)     Open Access   (Followers: 3)
Industrial Electronics, IEEE Transactions on     Hybrid Journal   (Followers: 74)
Industrial Technology Research Journal Phranakhon Rajabhat University     Open Access  
Industry Applications, IEEE Transactions on     Hybrid Journal   (Followers: 38)
Informatik-Spektrum     Hybrid Journal   (Followers: 2)
Instabilities in Silicon Devices     Full-text available via subscription   (Followers: 1)
Intelligent Transportation Systems Magazine, IEEE     Full-text available via subscription   (Followers: 13)
International Journal of Advanced Research in Computer Science and Electronics Engineering     Open Access   (Followers: 18)
International Journal of Advances in Telecommunications, Electrotechnics, Signals and Systems     Open Access   (Followers: 11)
International Journal of Antennas and Propagation     Open Access   (Followers: 11)
International Journal of Applied Electronics in Physics & Robotics     Open Access   (Followers: 4)
International Journal of Computational Vision and Robotics     Hybrid Journal   (Followers: 5)
International Journal of Control     Hybrid Journal   (Followers: 11)
International Journal of Electronics     Hybrid Journal   (Followers: 7)
International Journal of Electronics and Telecommunications     Open Access   (Followers: 13)
International Journal of Granular Computing, Rough Sets and Intelligent Systems     Hybrid Journal   (Followers: 3)
International Journal of High Speed Electronics and Systems     Hybrid Journal  
International Journal of Hybrid Intelligence     Hybrid Journal  
International Journal of Image, Graphics and Signal Processing     Open Access   (Followers: 16)
International Journal of Microwave and Wireless Technologies     Hybrid Journal   (Followers: 10)
International Journal of Nanoscience     Hybrid Journal   (Followers: 1)
International Journal of Numerical Modelling: Electronic Networks, Devices and Fields     Hybrid Journal   (Followers: 4)
International Journal of Power Electronics     Hybrid Journal   (Followers: 25)
International Journal of Review in Electronics & Communication Engineering     Open Access   (Followers: 4)
International Journal of Sensors, Wireless Communications and Control     Hybrid Journal   (Followers: 10)
International Journal of Systems, Control and Communications     Hybrid Journal   (Followers: 4)
International Journal of Wireless and Microwave Technologies     Open Access   (Followers: 6)
International Transaction of Electrical and Computer Engineers System     Open Access   (Followers: 2)
JAREE (Journal on Advanced Research in Electrical Engineering)     Open Access  
Journal of Biosensors & Bioelectronics     Open Access   (Followers: 4)
Journal of Advanced Dielectrics     Open Access   (Followers: 1)
Journal of Artificial Intelligence     Open Access   (Followers: 11)
Journal of Circuits, Systems, and Computers     Hybrid Journal   (Followers: 4)
Journal of Computational Intelligence and Electronic Systems     Full-text available via subscription   (Followers: 1)
Journal of Electrical and Electronics Engineering Research     Open Access   (Followers: 35)
Journal of Electrical Bioimpedance     Open Access  
Journal of Electrical Bioimpedance     Open Access   (Followers: 2)
Journal of Electrical Engineering & Electronic Technology     Hybrid Journal   (Followers: 7)
Journal of Electrical, Electronics and Informatics     Open Access  
Journal of Electromagnetic Analysis and Applications     Open Access   (Followers: 8)
Journal of Electromagnetic Waves and Applications     Hybrid Journal   (Followers: 9)
Journal of Electronic Design Technology     Full-text available via subscription   (Followers: 6)
Journal of Electronics (China)     Hybrid Journal   (Followers: 5)
Journal of Energy Storage     Full-text available via subscription   (Followers: 4)
Journal of Engineered Fibers and Fabrics     Open Access   (Followers: 2)
Journal of Field Robotics     Hybrid Journal   (Followers: 3)
Journal of Guidance, Control, and Dynamics     Hybrid Journal   (Followers: 176)
Journal of Information and Telecommunication     Open Access   (Followers: 1)
Journal of Intelligent Procedures in Electrical Technology     Open Access   (Followers: 3)
Journal of Low Power Electronics     Full-text available via subscription   (Followers: 10)
Journal of Low Power Electronics and Applications     Open Access   (Followers: 10)
Journal of Microelectronics and Electronic Packaging     Hybrid Journal  
Journal of Microwave Power and Electromagnetic Energy     Hybrid Journal   (Followers: 3)
Journal of Microwaves, Optoelectronics and Electromagnetic Applications     Open Access   (Followers: 11)
Journal of Nuclear Cardiology     Hybrid Journal  
Journal of Optoelectronics Engineering     Open Access   (Followers: 4)
Journal of Physics B: Atomic, Molecular and Optical Physics     Hybrid Journal   (Followers: 29)
Journal of Power Electronics & Power Systems     Full-text available via subscription   (Followers: 11)
Journal of Semiconductors     Full-text available via subscription   (Followers: 5)
Journal of Sensors     Open Access   (Followers: 26)
Journal of Signal and Information Processing     Open Access   (Followers: 9)
Jurnal ELTIKOM : Jurnal Teknik Elektro, Teknologi Informasi dan Komputer     Open Access  
Jurnal Rekayasa Elektrika     Open Access  
Jurnal Teknik Elektro     Open Access  
Jurnal Teknologi Elektro     Open Access  
Kinetik : Game Technology, Information System, Computer Network, Computing, Electronics, and Control     Open Access  
Learning Technologies, IEEE Transactions on     Hybrid Journal   (Followers: 12)
Magnetics Letters, IEEE     Hybrid Journal   (Followers: 7)
Majalah Ilmiah Teknologi Elektro : Journal of Electrical Technology     Open Access   (Followers: 2)
Metrology and Measurement Systems     Open Access   (Followers: 6)
Microelectronics and Solid State Electronics     Open Access   (Followers: 28)
Nanotechnology Magazine, IEEE     Full-text available via subscription   (Followers: 42)
Nanotechnology, Science and Applications     Open Access   (Followers: 6)
Nature Electronics     Hybrid Journal   (Followers: 1)
Networks: an International Journal     Hybrid Journal   (Followers: 5)
Open Electrical & Electronic Engineering Journal     Open Access  
Open Journal of Antennas and Propagation     Open Access   (Followers: 9)
Optical Communications and Networking, IEEE/OSA Journal of     Full-text available via subscription   (Followers: 15)
Paladyn. Journal of Behavioral Robotics     Open Access   (Followers: 1)
Power Electronics and Drives     Open Access   (Followers: 2)
Problemy Peredachi Informatsii     Full-text available via subscription  
Progress in Quantum Electronics     Full-text available via subscription   (Followers: 7)
Pulse     Full-text available via subscription   (Followers: 5)
Radiophysics and Quantum Electronics     Hybrid Journal   (Followers: 2)
Recent Advances in Communications and Networking Technology     Hybrid Journal   (Followers: 3)
Recent Advances in Electrical & Electronic Engineering     Hybrid Journal   (Followers: 9)
Research & Reviews : Journal of Embedded System & Applications     Full-text available via subscription   (Followers: 5)
Revue Méditerranéenne des Télécommunications     Open Access  
Security and Communication Networks     Hybrid Journal   (Followers: 2)
Selected Topics in Applied Earth Observations and Remote Sensing, IEEE Journal of     Hybrid Journal   (Followers: 56)
Semiconductors and Semimetals     Full-text available via subscription   (Followers: 1)
Sensing and Imaging : An International Journal     Hybrid Journal   (Followers: 2)
Services Computing, IEEE Transactions on     Hybrid Journal   (Followers: 4)
Software Engineering, IEEE Transactions on     Hybrid Journal   (Followers: 78)
Solid State Electronics Letters     Open Access  
Solid-State Circuits Magazine, IEEE     Hybrid Journal   (Followers: 13)
Solid-State Electronics     Hybrid Journal   (Followers: 9)
Superconductor Science and Technology     Hybrid Journal   (Followers: 3)
Synthesis Lectures on Power Electronics     Full-text available via subscription   (Followers: 3)
Technical Report Electronics and Computer Engineering     Open Access  
TELE     Open Access  
Telematique     Open Access  
TELKOMNIKA (Telecommunication, Computing, Electronics and Control)     Open Access   (Followers: 9)
Transactions on Electrical and Electronic Materials     Hybrid Journal  
Universal Journal of Electrical and Electronic Engineering     Open Access   (Followers: 6)
Ural Radio Engineering Journal     Open Access  
Visión Electrónica : algo más que un estado sólido     Open Access   (Followers: 1)
Wireless and Mobile Technologies     Open Access   (Followers: 6)
Wireless Power Transfer     Full-text available via subscription   (Followers: 4)
Women in Engineering Magazine, IEEE     Full-text available via subscription   (Followers: 11)
Електротехніка і Електромеханіка     Open Access  

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Journal Cover
Electronics
Journal Prestige (SJR): 0.548
Citation Impact (citeScore): 3
Number of Followers: 103  

  This is an Open Access Journal Open Access journal
ISSN (Print) 2079-9292
Published by MDPI Homepage  [222 journals]
  • Electronics, Vol. 8, Pages 1226: Software-Based Adaptive Protection
           Control Against Load Mismatch for a Mobile Power Amplifier Module

    • Authors: Jeon, Jung, Kang
      First page: 1226
      Abstract: A closed-loop protection method for a radio frequency (RF) power amplifier (PA) module applicable to mobile handsets has been introduced. The load impedance of the PA was adaptively sensed by an embedded impedance detector which was digitally controlled and the system adjusted PA power using a feedback circuit to keep the PA safe based on a load mismatch detection. For verification, a two-stage hetero junction bipolar transistor (HBT) PA module for handsets was fabricated and tested against load mismatch. Measurement results showed that the technique could help PA survive at a 0.5V larger collector bias voltage condition than when the technique was not applied for the same mismatch condition with an acceptable RF performance degradation at nominal condition.
      Citation: Electronics
      PubDate: 2019-10-27
      DOI: 10.3390/electronics8111226
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1227: Brush-Holder Integrated Load Sensor
           Prototype for SAG Grinding Mill Motor

    • Authors: Carrasco, Álvarez, Velázquez, Concha, Pérez-Cotapos
      First page: 1227
      Abstract: One of the most widely used electro-mechanical systems in large-scale mining is the electric motor. This device is employed in practically every phase of production. For this reason, it needs to be inspected regularly to maintain maximum operability, thus avoiding unplanned stoppages. In order to identify potential faults, regular check-ups are performed to measure the internal parameters of the components, especially the brushes and brush-holders. Both components must be properly aligned and calibrated to avoid electric arcs to the internal insulation of the motor. Although there is an increasing effort to improve inspection tasks, most inspection procedures are manual, leading to unnecessary costs in inspection time, errors in data entry, and, in extreme cases, measurement errors. This research presents the design, development, and assessment of an integrated measurement prototype for measuring spring tension and other key parameters in brush-holders used in electric motors. It aims to provide the mining industry with a new, fully automatic inspection system that will facilitate maintenance and checking. Our development research was carried out specifically on the brush system of a SAG grinding mill motor. These machines commonly use SIEMENS motors; however, the instrument can be easily adapted to any motor by simply changing the physical dimensions of the prototype.
      Citation: Electronics
      PubDate: 2019-10-27
      DOI: 10.3390/electronics8111227
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1228: A Millimeter-Wave Fundamental Frequency
           CMOS-Based Oscillator with High Output Power

    • Authors: Nguyen, Park, Hong
      First page: 1228
      Abstract: The millimeter-wave imaging approach is a promising candidate to satisfy the unmet needs of real-time biomedical imaging, such as resolution, focal area, and cost. As a part of the endeavor to make millimeter-wave imaging more feasible, this paper presents a CMOS oscillator generating a high output power at the millimeter-wave frequency range, with a high fundamental oscillation frequency. The proposed oscillator adopts a frequency-selective negative resistance topology to improve the negative transconductance and to increase the fundamental frequency of oscillation. The proposed oscillator was implemented in a 65 nm bulk CMOS process. The measured highest output power is –2.2 dBm at 190 GHz while dissipating 100 mW from a 2.8 V supply voltage.
      Citation: Electronics
      PubDate: 2019-10-27
      DOI: 10.3390/electronics8111228
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1229: Measurement of the PMSM Shaft Position
           with An Absolute Encoder

    • Authors: Tomasz Rudnicki
      First page: 1229
      Abstract: The most critical aspect of assessing a permanent magnet synchronous motor is the problem of correctly measuring the position of the synchronous motor shaft. The purpose of this article was to show the effects of employing an absolute encoder to control a synchronous motor with permanent magnets while encountering disturbances. This problem is often overlooked, but it appears from time to time. The correct measurement of the shaft position eliminates improper motor operation characterized by jerking. The article showed that despite momentary erroneous readings of the shaft’s position, it was still possible to control the permanent magnet synchronous motor (PMSM). This also allows for correct measurement of the motor speed. This paper originally proposed an adaptive correction method for a rotary encoder.
      Citation: Electronics
      PubDate: 2019-10-27
      DOI: 10.3390/electronics8111229
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1230: Performance Analysis of a Reduced
           Form-Factor High Accuracy Three-Axis Teslameter

    • Authors: Johann Cassar, Andrew Sammut, Nicholas Sammut, Marco Calvi, Sasa Spasic, Dragana Popovic Renella
      First page: 1230
      Abstract: In the framework of the SwissFEL project at the Paul Scherrer Institute (PSI), a Hall probe bench is being developed for the high-precision magnetic characterization of the insertion devices for the ATHOS soft X-ray beamline. For this purpose, a novel three-axis teslameter has been developed, which will be placed between the undulator and its outer shell in a very limited volumetric space of 150 × 50 × 45 mm. Together with a SENIS® 3-axis Hall probe at the center of the cross sectional area of the undulator, the setup will traverse along the undulator length on a specifically designed rig with minimal vibrations. This teslameter has all the analog signal conditioning circuitry for the Hall probe and also has on board 24-bit digitization. The instrument also handles an interface to a linear absolute encoder. The old instrumentation used only had analog signal conditioning circuitry whilst digitization was done off board. The new instrument also provides a very accurate magnetic field map in the µT range with simultaneous readings from the position encoder at an accuracy of ±3 µm. In this paper, a series of tests are described, which were performed at PSI in order to establish the measuring precision and repeatability of the instrument.
      Citation: Electronics
      PubDate: 2019-10-28
      DOI: 10.3390/electronics8111230
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1231: A High-Precision Gated Integrator for
           Repetitive Pulsed Signals Acquisition

    • Authors: Sara Pettinato, Andrea Orsini, Marco Girolami, Daniele Maria Trucchi, Maria Cristina Rossi, Stefano Salvatori
      First page: 1231
      Abstract: Gated integrating measurement method represents a widely used approach when fast, repetitive analogue signals are concerned. In this work a compact synchronized gated-integrator prototype has been realized and preliminary characterized. Front-end electronics is based on the mature high-precision switched-integrator transimpedance-amplifier IVC102 whose output is connected to a precision LT1911 inverting amplifier, whereas analogue-to-digital conversion, as well as timing control circuitry, are performed by a high-efficiency LPC845 microcontroller. Synchronizing signal detection with the external trigger generated in coincidence with a source, the proposed circuitry amplifies and integrates the signal only when the pulse is generated, displaying excellent performances in terms of linearity, sensitivity and signal-to-noise ratio. Hence, the proposed solution represents an affordable alternative to continuous-time regime measurement-techniques, usually adopted in radiation dosimetry where accuracy and sensitivity are strict requirements for treatment quality assurance.
      Citation: Electronics
      PubDate: 2019-10-28
      DOI: 10.3390/electronics8111231
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1232: A Miniaturized Butler Matrix Based
           Switched Beamforming Antenna System in a Two-Layer Hybrid Stackup
           Substrate for 5G Applications

    • Authors: Soyeon Kim, Seongjo Yoon, Yongho Lee, Hyunchol Shin
      First page: 1232
      Abstract: This work presents a Butler matrix based four-directional switched beamforming antenna system realized in a two-layer hybrid stackup substrate for 28-GHz mm-Wave 5G wireless applications. The hybrid stackup substrate is composed of two layers with different electrical and thermal properties. It is formed by attaching two layers by using prepreg, in which the circuit components are placed in both outer planes and the ground layers are placed in the middle. The upper layer that is used as antenna substrate has εr = 2.17, tanδ = 0.0009 and h = 0.254 mm. The lower layer that is used as a Butler matrix substrate has εr = 6.15, tanδ = 0.0028 and h = 0.254 mm. By realizing the antenna array on the lower-εr layer while the Butler matrix on the higher-εr layer, the Butler matrix dimension is significantly reduced without sacrificing the array antenna performance, leading to significant overall antenna system size reduction. The two-layer substrate approach also significantly suppresses parasitic radiation leaking from the Butler matrix toward the antenna side, allowing overall radiation pattern improvement. The fabricated beamforming antenna is composed of 1 × 4 patch antenna array and a 4 × 4 Butler matrix. The measured return loss is lower than −8 dB at all ports in 28-GHz. It demonstrates the switched beam steering toward four distinct angles of—16°, +36°, −39°, and +7°, with the sidelobe levels of −12, −11.7, −6, and −13.8 dB, respectively. Antenna gain is found to be about 10 dBi. Due to the two-layer hybrid stackup substrate, the total antenna system is realized only in 1.7λ × 2.1λ, which shows the smallest form factor compared to similar other works.
      Citation: Electronics
      PubDate: 2019-10-28
      DOI: 10.3390/electronics8111232
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1233: System Level Optimization for High-Speed
           SerDes: Background and the Road Towards Machine Learning Assisted Design
           Frameworks

    • Authors: Shiming Song, Yu Sui
      First page: 1233
      Abstract: This decade has witnessed wide use of data-driven systems, from multimedia to scientific computing, and in each case quality data movement infrastructure is required, many with SerDes as a cornerstone. On the one hand, HPC and machine learning cloud infrastructure carry exabytes of data in a year through the backplanes of data centers. On the other hand, the growing need for edge computing in the IoT places a tight envelope on the energy per bits. In this survey, we give a system level overview of the common design challenges in implementing SerDes solutions under different scenarios and propose simulation methods benefiting from advanced machine learning techniques. Preliminary results with the proposed simulation platform are demonstrated and analyzed through machine learning based design methodologies.
      Citation: Electronics
      PubDate: 2019-10-28
      DOI: 10.3390/electronics8111233
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1234: Wideband Performance Comparison between
           the 40 GHz and 60 GHz Frequency Bands for Indoor Radio Channels

    • Authors: Miguel Riobó, Rob Hofman, Iñigo Cuiñas, Manuel García Sánchez, Jo Verhaevert
      First page: 1234
      Abstract: When 5G networks are to be deployed, the usability of millimeter-wave frequency allocations seems to be left out of the debate. However, there is an open question regarding the advantages and disadvantages of the main candidates for this allocation: The use of the licensed spectrum near 40 GHz or the unlicensed band at 60 GHz. Both bands may be adequate for high performance radio communication systems, and this paper provides insight into such alternatives. A large measurement campaign supplied enough data to analyze and to evaluate the network performance for both frequency bands in different types of indoor environments: Both large rooms and narrow corridors, and both line of sight and obstructed line of sight conditions. As a result of such a campaign and after a deep analysis in terms of wideband parameters, the radio channel usability is analyzed with numerical data regarding its performance.
      Citation: Electronics
      PubDate: 2019-10-29
      DOI: 10.3390/electronics8111234
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1235: A Review of Automatic Phenotyping
           Approaches using Electronic Health Records

    • Authors: Hadeel Alzoubi, Raid Alzubi, Naeem Ramzan, Daune West, Tawfik Al-Hadhrami, Mamoun Alazab
      First page: 1235
      Abstract: Electronic Health Records (EHR) are a rich repository of valuable clinical information that exist in primary and secondary care databases. In order to utilize EHRs for medical observational research a range of algorithms for automatically identifying individuals with a specific phenotype have been developed. This review summarizes and offers a critical evaluation of the literature relating to studies conducted into the development of EHR phenotyping systems. This review describes phenotyping systems and techniques based on structured and unstructured EHR data. Articles published on PubMed and Google scholar between 2013 and 2017 have been reviewed, using search terms derived from Medical Subject Headings (MeSH). The popularity of using Natural Language Processing (NLP) techniques in extracting features from narrative text has increased. This increased attention is due to the availability of open source NLP algorithms, combined with accuracy improvement. In this review, Concept extraction is the most popular NLP technique since it has been used by more than 50% of the reviewed papers to extract features from EHR. High-throughput phenotyping systems using unsupervised machine learning techniques have gained more popularity due to their ability to efficiently and automatically extract a phenotype with minimal human effort.
      Citation: Electronics
      PubDate: 2019-10-29
      DOI: 10.3390/electronics8111235
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1236: A Life Prediction Model of Flywheel
           Systems Using Stochastic Hybrid Automaton

    • Authors: Cheng, Jiang, Han, Wang
      First page: 1236
      Abstract: This paper proposes a practical life prediction model for Flywheel Systems (FSs) using the Stochastic Hybrid Automaton (SHA) method. The reliability of motors and the performance degradation of bearings are considered key causes of the failure of FSs. The unit flywheel SHA model is established for the failure mechanism, considering burst failure of motors and the accumulated performance degradation of bearings. This prediction model also describes the dynamic relation of lifetime with the configurations of FSs, work modes, and running environments. Monte Carlo simulation results demonstrate that the life distributions of FSs are quite different if the spacecrafts run in various orbits or with different configurations, or under changed work modes. The proposed method provides an engineering reference and guidance for the scheme design and in-orbit mission planning of FSs.
      Citation: Electronics
      PubDate: 2019-10-29
      DOI: 10.3390/electronics8111236
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1237: Implementation of SOH Estimator in
           Automotive BMSs Using Recursive Least-Squares

    • Authors: Sung, Lee
      First page: 1237
      Abstract: This paper presents a computationally efficient state-of-health (SOH) estimator that is readily applicable to automotive battery management systems (BMSs). The proposed scheme uses a recursive estimator to improve the original scheme based on a batch estimator. In the batch process, state estimation requires significantly longer CPU time than data measurement, and the original scheme may fail to satisfy real-time guarantees. To prevent this problem, we apply recursive least-squares. By replacing the batch process to solve the normal equation with a recursive update, the proposed scheme can spread CPU utilization and reduce memory footprint. The benefits of the recursive estimator are quantitatively validated by comparing its CPU time and memory footprint with those of the batch estimator. A similar level of SOH estimation accuracy is achievable with over 60% less memory usage, and the CPU time stabilizes around 5 ms. This enables implementation of the proposed scheme in automotive BMSs.
      Citation: Electronics
      PubDate: 2019-10-29
      DOI: 10.3390/electronics8111237
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1238: Efficient Implementation on Low-Cost
           SoC-FPGAs of TLSv1.2 Protocol with ECC_AES Support for Secure IoT
           Coordinators

    • Authors: Ahmed Mohamed Bellemou, Antonio García, Encarnación Castillo, Nadjia Benblidia, Mohamed Anane, José Antonio Álvarez-Bermejo, Luis Parrilla
      First page: 1238
      Abstract: Security management for IoT applications is a critical research field, especially when taking into account the performance variation over the very different IoT devices. In this paper, we present high-performance client/server coordinators on low-cost SoC-FPGA devices for secure IoT data collection. Security is ensured by using the Transport Layer Security (TLS) protocol based on the TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256 cipher suite. The hardware architecture of the proposed coordinators is based on SW/HW co-design, implementing within the hardware accelerator core Elliptic Curve Scalar Multiplication (ECSM), which is the core operation of Elliptic Curve Cryptosystems (ECC). Meanwhile, the control of the overall TLS scheme is performed in software by an ARM Cortex-A9 microprocessor. In fact, the implementation of the ECC accelerator core around an ARM microprocessor allows not only the improvement of ECSM execution but also the performance enhancement of the overall cryptosystem. The integration of the ARM processor enables to exploit the possibility of embedded Linux features for high system flexibility. As a result, the proposed ECC accelerator requires limited area, with only 3395 LUTs on the Zynq device used to perform high-speed, 233-bit ECSMs in 413 µs, with a 50 MHz clock. Moreover, the generation of a 384-bit TLS handshake secret key between client and server coordinators requires 67.5 ms on a low cost Zynq 7Z007S device.
      Citation: Electronics
      PubDate: 2019-10-30
      DOI: 10.3390/electronics8111238
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1239: Video Streaming in Urban Vehicular
           Environments: Junction-Aware Multipath Approach

    • Authors: Ahmed Aliyu, Hesham El-Sayed, Abdul Hanan Abdullah, Intyaz Alam, Jun Li, Mukesh Prasad
      First page: 1239
      Abstract: In multipath video streaming transmission, the selection of the best vehicle for video packet forwarding considering the junction area is a challenging task due to the several diversions in the junction area. The vehicles in the junction area change direction based on the different diversions, which lead to video packet drop. In the existing works, the explicit consideration of different positions in the junction areas has not been considered for forwarding vehicle selection. To address the aforementioned challenges, a Junction-Aware vehicle selection for Multipath Video Streaming (JA-MVS) scheme has been proposed. The JA-MVS scheme considers three different cases in the junction area including the vehicle after the junction, before the junction and inside the junction area, with an evaluation of the vehicle signal strength based on the signal to interference plus noise ratio (SINR), which is based on the multipath data forwarding concept using greedy-based geographic routing. The performance of the proposed scheme is evaluated based on the Packet Loss Ratio (PLR), Structural Similarity Index (SSIM) and End-to-End Delay (E2ED) metrics. The JA-MVS is compared against two baseline schemes, Junction-Based Multipath Source Routing (JMSR) and the Adaptive Multipath geographic routing for Video Transmission (AMVT), in urban Vehicular Ad-Hoc Networks (VANETs).
      Citation: Electronics
      PubDate: 2019-10-30
      DOI: 10.3390/electronics8111239
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1240: Tilted-Beam Switched Array Antenna for
           UAV Mounted Radar Applications with 360° Coverage

    • Authors: Cheol Ung Lee, Gunhark Noh, ByungKuon Ahn, Jong-Won Yu, Han Lim Lee
      First page: 1240
      Abstract: A highly efficient antenna array for unmanned aerial vehicle (UAV) mounted radar applications with a tilted-beam characteristic and a 360° beam coverage is proposed in this paper. The proposed array antenna is configured by four planar super J-pole antennas with 2-dimensional ground reflectors. Each super J-pole antenna element provides a high directivity where the peak gain is tilted about 45° facing toward the ground from the bottom of a UAV body. Thus, the air-to-ground communication difficulty due to the altitude difference between the UAV and ground targets can be effectively solved. Further, the four super J-pole elements with a switched operation can cover the whole 360° areas around the UAV while high antenna gain is maintained. To verify the performance, the proposed structure was implemented at 5.9 GHz with an overall volume of 0.88 × 0.88 × 0.83 λo3. The measured 10-dB impedance bandwidths for all four antenna elements were better than 27.2% and the isolation among the four antenna ports was also always better than 13 dB. The measured peak gain was better than 7.4 dBi and tilted at 45° in the elevation angle. Lastly, the measured half power beam widths in elevation and azimuth planes were more than 60° and 87°, respectively.
      Citation: Electronics
      PubDate: 2019-10-30
      DOI: 10.3390/electronics8111240
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1241: Compact Differential-Fed Planar Filtering
           Antennas

    • Authors: Emadeldeen Hassan, Denys Martynenko, Eddie Wadbro, Gunter Fischer, Martin Berggren
      First page: 1241
      Abstract: This paper proposes novel low-profile differential-fed planar antennas with embedded sharp frequency selectively. The antennas are compact and easy to integrate with differential devices without matching baluns. The antenna design is formulated as a topology optimization problem, where requirements on impedance bandwidth, directivity, and filtering are used as the design objectives. The optimized antennas operate over the frequency band 6.0–8.5 GHz. The antennas have reflection coefficients below −15 dB, cross-polarization levels below −42 dB, a maximum gain of 6.0 ± 0.5 dB, and a uniform directivity over more than 130° beamwidth angle in the frequency band of interest. In addition, the antennas exhibit sharp roll-off between the operational band and frequencies around the 5.8 GHz WiFi band and the 10 GHz X-band. One antenna has been fabricated with a good match between simulation and measurement results.
      Citation: Electronics
      PubDate: 2019-10-30
      DOI: 10.3390/electronics8111241
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1242: SmartX Box: Virtualized Hyper-Converged
           Resources for Building an Affordable Playground

    • Authors: Aris Cahyadi Risdianto, Muhammad Usman, JongWon Kim
      First page: 1242
      Abstract: In this paper, we present our proposals and efforts for building an affordable playground (i.e., miniaturized testbed) for Software-Defined Networking (SDN)-Cloud experiments by using hyper-converged SmartX Boxes that are distributed across multiple sites. Each SmartX Box consists of several virtualized functions that are categorized into SDN and cloud functions. Multiple SmartX Boxes are deployed and inter-connected through SDN to build multi-site distributed cloud playground resources. The resulting deployment integrates both cloud multi-tenancy and SDN-based slicing, which allow developers to run experiments and operators to monitor resources in a distributed SDN-cloud playground. It also describes how the hyper-converged SmartX Box can increase the affordability of the playground deployment. Thus, the analysis result shows the efficiency of SmartX Box for building a distributed playground by providing semi-automated DevOps-style resource provisioning.
      Citation: Electronics
      PubDate: 2019-10-30
      DOI: 10.3390/electronics8111242
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1243: Design Methodology for the Implementation
           of Fuzzy Inference Systems Based on Boolean Relations

    • Authors: Helbert Espitia, José Soriano, Iván Machón, Hilario López
      First page: 1243
      Abstract: This paper proposes a methodology for the design of fuzzy inference systems based on Boolean relations. The approach using Boolean sets presents limited performance due to the abrupt transitions that occur during its functioning, therefore, fuzzy sets can be used aiming the improvement of the performance. In this approach, firstly, the design of a Boolean controller is performed, which is later extended into fuzzy under design guidelines proposed in this paper. The methodology uses Kleene algebra via truth tables for the fuzzy system design, allowing the simplification of the equations that implement the fuzzy system.
      Citation: Electronics
      PubDate: 2019-10-30
      DOI: 10.3390/electronics8111243
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1244: Myoelectric Control for Upper Limb
           Prostheses

    • Authors: Carles Igual, Luis A. Pardo, Jr. Hahne, Janne M. Igual
      First page: 1244
      Abstract: State-of-the-art high-end prostheses are electro-mechanically able to provide a great variety of movements. Nevertheless, in order to functionally replace a human limb, it is essential that each movement is properly controlled. This is the goal of prosthesis control, which has become a growing research field in the last decades, with the ultimate goal of reproducing biological limb control. Therefore, exploration and development of prosthesis control are crucial to improve many aspects of an amputee’s life. Nowadays, a large divergence between academia and industry has become evident in commercial systems. Although several studies propose more natural control systems with promising results, basic one degree of freedom (DoF), a control switching system is the most widely used option in industry because of simplicity, robustness and inertia. A few classification controlled prostheses have emerged in the last years but they are still a low percentage of the used ones. One of the factors that generate this situation is the lack of robustness of more advanced control algorithms in daily life activities outside of laboratory conditions. Because of this, research has shifted towards more functional prosthesis control. This work reviews the most recent literature in upper limb prosthetic control. It covers commonly used variants of possible biological inputs, its processing and translation to actual control, mostly focusing on electromyograms as well as the problems it will have to overcome in near future.
      Citation: Electronics
      PubDate: 2019-10-30
      DOI: 10.3390/electronics8111244
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1245: Performance Evaluation of Group Sparse
           Reconstruction and Total Variation Minimization for Target Imaging in
           Stratified Subsurface Media

    • Authors: Fauzia Ahmad, Ahmad Hoorfar, Wenji Zhang
      First page: 1245
      Abstract: Sparse reconstruction methods have been successfully applied for efficient radar imaging of targets embedded in stratified dielectric subsurface media. Recently, a total variation minimization (TVM) based approach was shown to provide superior image reconstruction performance over standard L1-norm minimization-based method, especially in case of non-point-like targets. Alternatively, group sparse reconstruction (GSR) schemes can also be employed to account for embedded target extent. In this paper, we provide qualitative and quantitative performance evaluations of TVM and GSR schemes for efficient and reliable target imaging in stratified subsurface media. Using numerical electromagnetic data of targets buried in the ground, we demonstrate that GSR and TVM provide comparable reconstruction performance qualitatively, with GSR exhibiting a slight superiority over TVM quantitatively, albeit at the expense of less flexibility in regularization parameters.
      Citation: Electronics
      PubDate: 2019-10-30
      DOI: 10.3390/electronics8111245
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1246: Broadband High-Gain Antenna for
           Millimetre-Wave 60-GHz Band

    • Authors: Khaled Issa, Habib Fathallah, Muhammad A. Ashraf, Hamsakutty Vettikalladi, Saleh Alshebeili
      First page: 1246
      Abstract: This paper focuses on the 60 GHz band, which is known to be very attractive for enabling next-generation abundant multi-Gbps wireless connectivity in 5G communication. We propose a novel concept of a double-layer antenna, loosely inspired from standard log-periodic schemes but with an aperiodic geometry, reduced size, and a limited number of elements while achieving excellent performance over the entire 60 GHz band. To maximize the antenna’s efficiency, we have developed a design that differs from those traditionally used for millimeter-wave communication applications. We aim to simultaneously maximize the gain, efficiency, and bandwidth. The reflection coefficient of the proposed design achieves a bandwidth of 20.66% from 53.9 GHz up to 66.3 GHz, covering the entire frequency band of interest. In addition, this proposed structure achieves a maximum realized gain of 11.8 dBi with an estimated radiation efficiency of 91.2%. The proposed antenna is simulated, fabricated, and tested in an anechoic chamber environment. The measurement data show a reasonable agreement with the simulation results, with respect to the bandwidth, gain, and side-lobe level over the operational spectrum.
      Citation: Electronics
      PubDate: 2019-10-31
      DOI: 10.3390/electronics8111246
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1247: Satellite IoT Edge Intelligent Computing:
           A Research on Architecture

    • Authors: Junyong Wei, Jiarong Han, Suzhi Cao
      First page: 1247
      Abstract: As the number of satellites continues to increase, satellites become an important part of the IoT and 5G/6G communications. How to deal with the data of the satellite Internet of Things is a problem worth considering and paying attention to. Due to the current on-board processing capability and the limitation of the inter-satellite communication rate, the data acquisition from the satellite has a higher delay and the data utilization rate is lower. In order to use the data generated by the satellite IoT more effectively, we propose a satellite IoT edge intelligent computing architecture. In the article, we analyze the current methods of satellite data processing, combined with the development trend of future satellites, and use the characteristics of edge computing and machine learning to describe the satellite IoT edge intelligent computing architecture. Finally, we verify that the architecture can speed up the processing of satellite data. By demonstrating the performance of different neural network models in the satellite edge intelligent computing architecture, we can find that the lightweight of neural networks can promote the development of satellite IoT edge intelligent computing architecture.
      Citation: Electronics
      PubDate: 2019-10-31
      DOI: 10.3390/electronics8111247
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1248: Post Text Processing of Chinese Speech
           Recognition Based on Bidirectional LSTM Networks and CRF

    • Authors: Li Yang, Ying Li, Jin Wang, Zhuo Tang
      First page: 1248
      Abstract: With the rapid development of Internet of Things Technology, speech recognition has been applied more and more widely. Chinese Speech Recognition is a complex process. In the process of speech-to-text conversion, due to the influence of dialect, environmental noise, and context, the accuracy of speech-to-text in multi-round dialogues and specific contexts is still not high. After the general speech recognition technology, the text after speech recognition can be detected and corrected in the specific context, which is helpful to improve the robustness of text comprehension and is a beneficial supplement to the speech recognition technology. In this paper, a text processing model after Chinese Speech Recognition is proposed, which combines a bidirectional long short-term memory (LSTM) network with a conditional random field (CRF) model. The task is divided into two stages: text error detection and text error correction. In this paper, a bidirectional long short-term memory (Bi-LSTM) network and conditional random field are used in two stages of text error detection and text error correction respectively. Through verification and system test on the SIGHAN 2013 Chinese Spelling Check (CSC) dataset, the experimental results show that the model can effectively improve the accuracy of text after speech recognition.
      Citation: Electronics
      PubDate: 2019-10-31
      DOI: 10.3390/electronics8111248
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1249: Research on Linear Active Disturbance
           Rejection Control in DC/DC Boost Converter

    • Authors: Hui Li, Xinxiu Liu, Junwei Lu
      First page: 1249
      Abstract: This paper proposes a cascade control strategy based on linear active disturbance rejection control (LADRC) for a boost DC/DC converter. It solves the problem that the output voltage of boost converter is unstable due to non-minimum phase characteristics, input voltage and load variation. Firstly, the average state space model of boost converter is established. Secondly, a new output variable is selected, and a cascade control is adopted to solve the problems of narrow bandwidth and poor dynamic performance caused by non-minimum phase. LADRC is used to estimate and compensate the fluctuations of input voltage and loads in time. Linear state error feedback (LSEF) is used to achieve smaller errors than traditional control method, which ensures the stability and robustness of the system under internal uncertainty and external disturbance. Subsequently, the stability of the system is determined by frequency domain analysis. Finally, the feasibility and superiority of the proposed strategy is verified by simulation and hardware experiment.
      Citation: Electronics
      PubDate: 2019-10-31
      DOI: 10.3390/electronics8111249
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1250: Melody Extraction and Encoding Method for
           Generating Healthcare Music Automatically

    • Authors: Shuyu Li, Sejun Jang, Yunsick Sung
      First page: 1250
      Abstract: The strong relationship between music and health has helped prove that soft and peaceful classical music can significantly reduce people’s stress; however, it is difficult to identify and collect examples of such music to build a library. Therefore, a system is required that can automatically generate similar classical music selections from a small amount of input music. Melody is the main element that reflects the rhythms and emotions of musical works; therefore, most automatic music generation research is based on melody. Given that melody varies frequently within musical bars, the latter are used as the basic units of composition. As such, there is a requirement for melody extraction techniques and bar-based encoding methods for automatic generation of bar-based music using melodies. This paper proposes a method that handles melody track extraction and bar encoding. First, the melody track is extracted using a pitch-based term frequency–inverse document frequency (TFIDF) algorithm and a feature-based filter. Subsequently, four specific features of the notes within a bar are encoded into a fixed-size matrix during bar encoding. We conduct experiments to determine the accuracy of track extraction based on verification data obtained with the TFIDF algorithm and the filter; an accuracy of 94.7% was calculated based on whether the extracted track was a melody track. The estimated value demonstrates that the proposed method can accurately extract melody tracks. This paper discusses methods for automatically extracting melody tracks from MIDI files and encoding based on bars. The possibility of generating music through deep learning neural networks is facilitated by the methods we examine within this work. To help the neural networks generate higher quality music, which is good for human health, the data preprocessing methods contained herein should be improved in future works.
      Citation: Electronics
      PubDate: 2019-10-31
      DOI: 10.3390/electronics8111250
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1251: Application of Histogram-Based Outlier
           Scores to Detect Computer Network Anomalies

    • Authors: Nerijus Paulauskas, Algirdas Baskys
      First page: 1251
      Abstract: Misuse activity in computer networks constantly creates new challenges and difficulties to ensure data confidentiality, integrity, and availability. The capability to identify and quickly stop the attacks is essential, as the undetected and successful attack may cause losses of critical resources. The anomaly-based intrusion detection system (IDS) is a valuable security tool that is capable of detecting new, previously unseen attacks. Anomaly-based IDS sends an alarm when it detects an event that deviates from the behavior characterized as normal. This paper analyses the use of the histogram-based outlier score (HBOS) to detect anomalies in the computer network. Experimental results of different histogram creation methods and the influence of the number of bins on the performance of anomaly detection are presented. Experiments were conducted using an NSL-KDD dataset.
      Citation: Electronics
      PubDate: 2019-11-01
      DOI: 10.3390/electronics8111251
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1252: A Vehicle Target Recognition Algorithm
           for Wide-Angle SAR Based on Joint Feature Set Matching

    • Authors: Rongchun Hu, Zhenming Peng, Juan Ma
      First page: 1252
      Abstract: Target recognition is an important area in Synthetic Aperture Radar (SAR) research. Wide-angle Synthetic Aperture Radar (WSAR) has obvious advantages in target imaging resolution. This paper presents a vehicle target recognition algorithm for wide-angle SAR, which is based on joint feature set matching (JFSM). In this algorithm, firstly, the modulus stretch step is added in the imaging process of wide-angle SAR to obtain the thinned image of vehicle contour. Secondly, the gravitational-based speckle reduction algorithm is used to obtain a clearer contour image. Thirdly, the image is rotated to obtain a standard orientation image. Subsequently, the image and projection feature sets are extracted. Finally, the JFSM algorithm, which combines the image and projection sets, is used to identify the vehicle model. Experiments show that the recognition accuracy of the proposed algorithm is up to 85%. The proposed algorithm is demonstrated on the Gotcha WSAR dataset.
      Citation: Electronics
      PubDate: 2019-11-01
      DOI: 10.3390/electronics8111252
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1253: Novel Wood Resistance Measurement Method
           Reducing the Initial Transient Instabilities Arising in DC Methods Due to
           Polarization Effects

    • Authors: Silvia Casans Berga, Rafael Garcia-Gil, A. Edith Navarro Anton, Alfredo Rosado-Muñoz
      First page: 1253
      Abstract: A novel method for measuring the electrical resistance in wood is presented. It is based on applying an Alternating Current (AC) to two electrodes rammed into the wood. The method reduces the transient time for value stabilization. In case of Direct Current (DC) resistance measurement methods, typically used in wood measurement, an initial transient exists, invalidating the measured value during an initial transient period. This measurement method uses an electronic circuit based on a relaxation oscillator where the wood automatically sets the oscillation frequency depending on its electrical resistance. Compared to other AC methods, this circuit greatly simplifies the measurement process, not requiring any previous analysis for wood AC frequency estimation. Experimental results for four different wood species showed that, in all cases, the transient response of the measured wood resistance is improved when compared to the DC resistance method, reducing the stabilization time from 10–12 min in DC measurements to almost zero for the novel measurement method. The deviation between the initial wood resistance measurement and the stable value resulted in a range between 0.2% and 5% with the proposed method, while a range between 6% and 10% was obtained when using the DC method. Moreover, the proposed circuit is able to detect changes in wood resistance produced by small variations in temperature and environmental relative humidity during continuous long term measurements. For repeatability analysis, it was verified that similar ambient conditions of temperature and relative humidity (variations lower than 1 °C and 1%, respectively) in different moments provided variations lower than 1.5%. The method can also be applied to other fiber materials affectd by polarization effects when an electrical current is applied into them.
      Citation: Electronics
      PubDate: 2019-11-01
      DOI: 10.3390/electronics8111253
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1254: Cooperative Non-Orthogonal Multiple
           Access over Log-Normal Power Line Communication Channels

    • Authors: Roger Kwao Ahiadormey, Prince Anokye, Kyoung-Jae Lee
      First page: 1254
      Abstract: In this paper, we analyze the performance of cooperative power domain non-orthogonal multiple access (NOMA) in power line communication (PLC) networks. Due to the high signal attenuation of the source to user links, a relay aids communication from the source to two users. With half-duplex transmission, the source transmits a superimposed symbol in the first phase. The relay utilizes amplify-and-forward (AF) and decode-and-forward (DF) protocol on the received superimposed signal and forwards it to the users in the second phase. We derive analytic expressions for the outage probability and the system throughput of the proposed system under a PLC log-normal channel with impulsive noise. Based on the results for AF NOMA relaying case, we analyze the system performance at high signal-to-noise ratio (SNR) and derive closed-form lower and upper bounds for the outage probability. Simulation results show an improvement in the outage probability and the system throughput performance of the AF and DF NOMA schemes compared to the NOMA without relaying transmission and conventional orthogonal multiple access scheme. Furthermore, the impact of the channel variance is highlighted in the results. It is shown that the DF NOMA has a better outage probability than the AF NOMA scheme for low channel variance scenarios (i.e., less branches and connected loads in the PLC network). However, as the channel variance increases, AF NOMA scheme has similar outage probability performance as the DF NOMA scheme. In addition, it is shown that the system throughput is enhanced when the relay employs DF relaying compared to AF relaying.
      Citation: Electronics
      PubDate: 2019-11-01
      DOI: 10.3390/electronics8111254
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1255: Comparison of Power Converter Models with
           Losses for Hardware-in-the-Loop Using Different Numerical Formats

    • Authors: Elyas Zamiri, Alberto Sanchez, Angel de Castro, Maria Sofia Martínez-García
      First page: 1255
      Abstract: Nowadays, the Hardware-In-the-Loop (HIL) technique is widely used to test different power electronic converters. These real-time simulations require processing large data at high speed, which makes this application very suitable for FPGAs (Field Programmable Gate Array) as they are capable of parallel processing. This paper provides an analytical discussion on three HIL models for a full-bridge converter. The three models use different possible numerical formats, namely float and fixed-point, the latter with and without optimizing the width of signals to the embedded DSP (Digital Signal Processors) blocks of the FPGA. The optimized fixed-point model (OFPM) uses three and two times fewer DSP blocks or LUTs (Look Up Tables), and the maximum achievable clock frequency is also up to 35 % and 25 % higher than the float model and non-optimized fixed-point model (nOFPM), respectively. Furthermore, the models’ accuracy is proportional to the clock frequency, thus the OFPM is also the most accurate model. Finally, the paper shows the differences in the simulation when the models include or not losses, proving that not including losses leads to high errors, especially during transients.
      Citation: Electronics
      PubDate: 2019-11-01
      DOI: 10.3390/electronics8111255
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1256: Open Electronics for Medical Devices:
           State-of-Art and Unique Advantages

    • Authors: Pandey, Vora
      First page: 1256
      Abstract: A wide range of medical devices have significant electronic components. Compared to open-source medical software, open (and open-source) electronic hardware has been less published in peer-reviewed literature. In this review, we explore the developments, significance, and advantages of using open platform electronic hardware for medical devices. Open hardware electronics platforms offer not just shorter development times, reduced costs, and customization; they also offer a key potential advantage which current commercial medical devices lack—seamless data sharing for machine learning and artificial intelligence. We explore how various electronic platforms such as microcontrollers, single board computers, field programmable gate arrays, development boards, and integrated circuits have been used by researchers to design medical devices. Researchers interested in designing low cost, customizable, and innovative medical devices can find references to various easily available electronic components as well as design methodologies to integrate those components for a successful design.
      Citation: Electronics
      PubDate: 2019-11-01
      DOI: 10.3390/electronics8111256
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1257: Innovative Use of Wrist-Worn Wearable
           Devices in the Sports Domain: A Systematic Review

    • Authors: Juan M. Santos-Gago, Mateo Ramos-Merino, Sonia Vallarades-Rodriguez, Luis M. Álvarez-Sabucedo, Manuel J. Fernández-Iglesias, Jose L. García-Soidán
      First page: 1257
      Abstract: Wrist wearables are becoming more and more popular, and its use is widespread in sports, both professional and amateur. However, at present, they do not seem to exploit all their potential. The objective of this study is to explore innovative proposals for the use of wearable wrist technology in the field of sports, to understand its potential and identify new challenges and lines of future research related to this technology. A systematic review of the scientific literature, collected in 4 major repositories, was carried out to locate research initiatives where wrist wearables were introduced to address some sports-related challenges. Those works that were limited to evaluating sensor performance in sports activities and those in which wrist wearable devices did not play a significant role were excluded. 26 articles were eventually selected for full-text analysis that discuss the introduction of wrist-worn wearables to address some innovative use in the sports field. This study showcases relevant proposals in 10 different sports. The research initiatives identified are oriented to the use of wearable wrist technology (i) for the comprehensive monitoring of sportspeople’s behavior in activities not supported by the vendors, (ii) to identify specific types of movements or actions in specific sports, and (iii) to prevent injuries. There are, however, open issues that should be tackled in the future, such as the incorporation of these devices in sports activities not currently addressed, or the provision of specific recommendation services for sport practitioners.
      Citation: Electronics
      PubDate: 2019-11-01
      DOI: 10.3390/electronics8111257
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1258: Utilizing a Building Information
           Modelling Environment to Communicate the Legal Ownership of Internet of
           Things-Generated Data in Multi-Owned Buildings

    • Authors: Behnam Atazadeh, Hamed Olfat, Behzad Rismanchi, Davood Shojaei, Abbas Rajabifard
      First page: 1258
      Abstract: In multi-owned buildings, a community of residents live in their private properties while they use and share communal spaces and facilities. Proper management of multi-owned buildings is underpinned by rules related to health, safety, and security of the residents and visitors. Utilizing Internet of Things (IoT) devices to collect information about the livable space has become a significant trend since the introduction of first smart home appliances back in 2000. The question about who owns the IoT generated data and under what terms it can be shared with others is still unclear. IoT devices, such as security camera and occupancy sensors, can provide safety for their owners, while these devices may capture private data from the neighborhood. In fact, the residents are sometimes not aware of regulations that can prevent them from installing and collecting data from shared spaces that could breach other individuals’ privacy. On the other hand, Building Information Modelling (BIM) provides a rich 3D digital data environment to manage the physical, functional, and ownership aspects of buildings over their entire lifecycle. This study aims to propose a methodology to utilize BIM for defining the legal ownership of the IoT generated data. A case study has been used to discuss key challenges related to the ownership of IoT data in a multi-owned building. This study confirmed that BIM environment can facilitate the understanding of legal ownership of IoT datasets and supports the interpretation of who has the entitlement to use the IoT datasets in multi-owned buildings.
      Citation: Electronics
      PubDate: 2019-11-01
      DOI: 10.3390/electronics8111258
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1259: High Accuracy Power Quality Evaluation
           under a Colored Noisy Condition by Filter Bank ESPRIT

    • Authors: Elaine Santos, Mahdi Khosravy, Marcelo A. A. Lima, Augusto S. Cerqueira, Carlos A. Duque, Atsushi Yona
      First page: 1259
      Abstract: Due to the highly increasing integration of renewable energy sources with the power grid and their fluctuations, besides the recent growth of new power electronics equipment, the noise in power systems has become colored. The colored noise affects the methodologies for power quality parameters’ estimation, such as harmonic and interharmonic components. Estimation of signal parameters via rotational invariance techniques (ESPRIT) as a parametric technique with high resolution has proven its efficiency in the estimation of power signal components’ frequencies, amplitudes, and phases for quality analysis, under the assumption of white Gaussian noise. Since ESPRIT suffers from high computational effort, filter bank ESPRIT (FB-ESPRIT) was suggested for mitigation of the complexity. This manuscript suggests FB-ESPRIT as well for accurate and robust estimation of power signal components’ parameters in the presence of the colored noise. Even though the parametric techniques depend on the Gaussianity of contaminating noise to perform properly, FB-ESPRIT performs well in colored noise. The FB-ESPRIT superiority compared with the conventional ESPRIT and MUSIC techniques was demonstrated through many simulations runs on synthetic power signals with multiple harmonics, interharmonics, and subharmonic components in the presence of noises of different colors and different SNR levels. FB-ESPRIT had a significant efficiency superiority in power quality analysis with a wide gap distance from the other estimators, especially under the high level of colored noise.
      Citation: Electronics
      PubDate: 2019-11-01
      DOI: 10.3390/electronics8111259
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1260: LDMOS versus GaN RF Power Amplifier
           Comparison Based on the Computing Complexity Needed to Linearize the
           Output

    • Authors: Raúl Gracia Sáez, Nicolás Medrano Marqués
      First page: 1260
      Abstract: In order to maximize the efficiency of telecommunications equipment, it is necessary that the radio frequency (RF) power amplifier is situated as closely as possible to its compression point. This makes its response nonlinear, and therefore it is necessary to linearize it, in order to minimize the interference that nonlinearities cause outside the useful band (adjacent channel). The system used for this linearization occupies a high percentage of the hardware and software resources of the telecommunication equipment, so it is interesting to minimize its complexity in order to make it as simple as possible. This paper analyzes the differences between the laterally diffused MOSFET (LDMOS) and gallium nitride (GaN) power amplifiers, in terms of their nonlinearity graphs, and in terms of the greater or lesser difficulty of linearization. A correct choice of power amplifier will allow for minimization of the linearization system, greatly simplifying the complexity of the final design.
      Citation: Electronics
      PubDate: 2019-11-01
      DOI: 10.3390/electronics8111260
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1261: Contribution to the Channel Path Loss and
           Time-Dispersion Characterization in an Office Environment at 26 GHz

    • Authors: Lorenzo Rubio, Rafael P. Torres, Vicent M. Rodrigo Peñarrocha, Jesús R. Pérez, Herman Fernández, Jose-Maria Molina-Garcia-Pardo, Juan Reig
      First page: 1261
      Abstract: In this paper, path loss and time-dispersion results of the propagation channel in a typical office environment are reported. The results were derived from a channel measurement campaign carried out at 26 GHz in line-of-sight (LOS) and obstructed-LOS (OLOS) conditions. The parameters of both the floating-intercept (FI) and close-in (CI) free space reference distance path loss models were derived using the minimum-mean-squared-error (MMSE). The time-dispersion characteristics of the propagation channel were analyzed through the root-mean-squared (rms) delay-spread and the coherence bandwidth. The results reported here provide better knowledge of the propagation channel features and can be also used to design and evaluate the performance of the next fifth-generation (5G) networks in indoor office environments at the potential 26 GHz frequency band.
      Citation: Electronics
      PubDate: 2019-11-01
      DOI: 10.3390/electronics8111261
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1262: The Cylindrical Wave Approach for the
           Electromagnetic Scattering by Targets behind a Wall

    • Authors: Cristina Ponti, Giuseppe Schettini
      First page: 1262
      Abstract: An overview of the cylindrical wave approach in the modeling of through-wall radar problems with targets hidden behind a dielectric wall is reported. The cylindrical wave approach is a technique for the solution of the two-dimensional scattering by buried circular cross-section cylinders in a semi-analytical way, through expansion of the scattered fields into cylindrical waves. In a through-wall radar application, the scattering environment is made by a dielectric layer between two semi-infinite half-spaces filled by air. For this layout, two possible implementations of the cylindrical wave approach have been developed in the case of plane-wave excitation. The first was an iterative scheme with multiple-reflection scattered fields, and the second was a fast and non-iterative solution, through suitable basis functions (i.e., reflected and transmitted cylindrical waves). Such waves take into account all the interactions of the source field with the interfaces bounding the dielectric layers and the targets. The non-iterative approach was also extended for excitation from the radiated field by a line source. A final system was derived for the computation of the scattered field by PEC or dielectric targets. Numerical results show the potentialities of the cylindrical wave approach in the modeling of through-wall radar, in particular in the evaluation of the scattered fields by human targets in a building’s interior, modeled with a two-dimensional approach.
      Citation: Electronics
      PubDate: 2019-11-01
      DOI: 10.3390/electronics8111262
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1263: Semi-Supervised Deep Time-Delay Embedded
           Clustering for Stress Speech Analysis

    • Authors: Barlian Henryranu Prasetio, Hiroki Tamura, Koichi Tanno
      First page: 1263
      Abstract: Real stressed speech is affected by various aspects (individual characteristics and environment) so that the stress patterns are diverse and different on each individual. To this end, in our previous work, we performed an unsupervised clustering method that able to self-learning manner by mapping the feature representations of the stress speech and clustering tasks simultaneously, called deep time-delay embedded clustering (DTEC). However, DTEC has not confirmed yet the compatibility between the output class and informational classes. Therefore, we proposed semi-supervised time-delay embedded clustering (SDTEC) as a new framework of semi-supervised in DTEC. SDTEC incorporates the prior information of pairwise constraints in the embedding layer and simultaneously learns the feature representation and the clustering assignments. The prior information was used to guide the clustering procedure so that the points that belong to the incorrect cluster can be corrected. The effectiveness of the proposed SDTEC was evaluated by comparing it with some baseline methods in terms of the clustering error rate (CER). Moreover, to demonstrate SDTEC’s capabilities, we conducted a comprehensive ablation study. Based on experiment results, SDTEC outperformed the baseline methods and achieves state-of-the-art results in semi-supervised clustering.
      Citation: Electronics
      PubDate: 2019-11-01
      DOI: 10.3390/electronics8111263
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1264: Control of MMC-Based STATCOM as an
           Effective Interface between Energy Sources and the Power Grid

    • Authors: Fatemeh Shahnazian, Ebrahim Adabi, Jafar Adabi, Edris Pouresmaeil, Kumars Rouzbehi, Eduardo M. G. Rodrigues, João P. S. Catalão
      First page: 1264
      Abstract: This paper presents a dynamic model of modular multilevel converters (MMCs), which are considered as an effective interface between energy sources and the power grid. By improving the converter performance, appropriate reactive power compensation is guaranteed. Modulation indices are calculated based on detailed harmonic evaluations of both dynamic and steady-state operation modes, which is considered as the main contribution of this paper in comparison with other methods. As another novelty of this paper, circulating current control is accomplished by embedding an additional second harmonic component in the modulation process. The proposed control method leads to an effective reduction in capacitor voltage fluctuation and losses. Finally, converter’s maximum stable operation range is modified, which provides efficiency enhancements and also stability assurance. The proficiency and functionality of the proposed controller are demonstrated through detailed theoretical analysis and simulations with MATLAB/Simulink.
      Citation: Electronics
      PubDate: 2019-11-01
      DOI: 10.3390/electronics8111264
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1265: Distributed Control Methods and Impact of
           Communication Failure in AC Microgrids: A Comparative Review

    • Authors: Aghaee, Mahdian Dehkordi, Bayati, Hajizadeh
      First page: 1265
      Abstract: The objectives of this paper are to review and compare the distributed control methods in AC microgrids and also to identify the impact of communication failure on this type of the controller. The current AC microgrids are distinguished from the traditional power system topologies because of the high penetration of advanced control methods, measurements, sensors, power electronic devices, and communication links. Also, because of the increasing integration of renewable energy sources, control strategy for congestion management, frequency control, and optimal dispatch of microgrids has become more complicated. This paper explains the characteristics and features of distributed control systems and discusses the challenges of these approaches. In addition, a comprehensive review of the advantages and disadvantages of these techniques are explained in detail. On the other hand, the possible challenges, related to communication failure, noise, delay, and packet dropout on the operation of the distributed controller are presented, and several techniques, which reduce the impact of communication failure of the distributed controller, are compared. This comprehensive study on distributed control systems reveals the challenges in and future possible studies on this issue.
      Citation: Electronics
      PubDate: 2019-11-01
      DOI: 10.3390/electronics8111265
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1266: Adaptive-Hybrid Redundancy with Error
           Injection

    • Authors: Nicolas Hamilton, Scott Graham, Timothy Carbino, James Petrosky, Addison Betances
      First page: 1266
      Abstract: Adaptive-Hybrid Redundancy (AHR) shows promise as a method to allow flexibility when selecting between processing speed and energy efficiency while maintaining a level of error mitigation in space radiation environments. Whereas previous work demonstrated AHR’s feasibility in an error free environment, this work analyzes AHR performance in the presence of errors. Errors are deliberately injected into AHR at specific times in the processing chain to demonstrate best and worst case performance impacts. This analysis demonstrates that AHR provides flexibility in processing speed and energy efficiency in the presence of errors.
      Citation: Electronics
      PubDate: 2019-11-01
      DOI: 10.3390/electronics8111266
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1267: An Approach to Hyperparameter
           Optimization for the Objective Function in Machine Learning

    • Authors: Yonghoon Kim, and Mokdong Chung
      First page: 1267
      Abstract: In machine learning, performance is of great value. However, each learning process requires much time and effort in setting each parameter. The critical problem in machine learning is determining the hyperparameters, such as the learning rate, mini-batch size, and regularization coefficient. In particular, we focus on the learning rate, which is directly related to learning efficiency and performance. Bayesian optimization using a Gaussian Process is common for this purpose. In this paper, based on Bayesian optimization, we attempt to optimize the hyperparameters automatically by utilizing a Gamma distribution, instead of a Gaussian distribution, to improve the training performance of predicting image discrimination. As a result, our proposed method proves to be more reasonable and efficient in the estimation of learning rate when training the data, and can be useful in machine learning.
      Citation: Electronics
      PubDate: 2019-11-01
      DOI: 10.3390/electronics8111267
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1268: Classification and Design Space
           Exploration of Low-Power Three-Stage Operational Transconductance
           Amplifier Architectures for Wide Load Ranges

    • Authors: Joseph Riad, Johan J. Estrada-López, Edgar Sánchez-Sinencio
      First page: 1268
      Abstract: Since operational transconductance amplifiers (OTAs) form the basic building blocks of many analog systems, the compensation of three-stage OTAs has attracted a lot of attention in the literature. Many different solutions to the stability problem of such OTAs have been proposed over the past 20 years, with each solution exhibiting different properties or targeting a different application. This work surveys a broad selection of previously reported architectures and proposes a novel classification scheme that exposes features common to seemingly different compensation architectures and serves as a guideline for which type of OTA is suitable for a given application. In addition, a novel figure of merit (FoM) is proposed to guide the designer in deciding which OTA architecture suits the tradeoffs specific to the application at hand. Theoretical discussions are further reinforced by transistor-level simulation results.
      Citation: Electronics
      PubDate: 2019-11-01
      DOI: 10.3390/electronics8111268
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1269: Comparing the Effectiveness of Scratch
           and App Inventor with Regard to Learning Computational Thinking Concepts

    • Authors: Youngki Park, Youhyun Shin
      First page: 1269
      Abstract: Scratch and App Inventor are two of the most widely used block-based programming languages for young students. These are educational languages which allow students to program easily by dragging and dropping their code blocks. One question that arises in relation to these educational languages is which of them would be more helpful in fostering computational thinking. It is difficult to answer this question because each language has its own advantages. In this paper, we propose a novel rubric based on Dr. Scratch for assessing both Scratch and App Inventor projects in terms of computational thinking concept learning. We crawled teachers’ and students’ open and popular projects and automatically calculated their effectiveness scores with regard to learning computational thinking concepts based on our rubric. The experimental results show that (1) Scratch projects scored higher on average in Parallelism, Synchronization and Flow Control, while App Inventor projects scored higher on average in User Interactivity and Data Representation. The results also show that (2) in many cases, large programs with numerous lines of code scored high in all areas of computational thinking concepts.
      Citation: Electronics
      PubDate: 2019-11-01
      DOI: 10.3390/electronics8111269
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1270: OTL-Classifier: Towards Imaging
           Processing for Future Unmanned Overhead Transmission Line Maintenance

    • Authors: Fan Zhang, Yalei Fan, Tao Cai, Wenda Liu, Zhongqiu Hu, Nengqing Wang, Minghu Wu
      First page: 1270
      Abstract: The global demand for electric power has been greatly increasing because of industrial development and the change in people’s daily life. A lot of overhead transmission lines have been installed to provide reliable power across long distancess. Therefore, research on overhead transmission lines inspection is very important for preventing sudden wide-area outages. In this paper, we propose an Overhead Transmission Line Classifier (OTL-Classifier) based on deep learning techniques to classify images returned by future unmanned maintenance drones or robots. In the proposed model, a binary classifier based on Inception architecture is incorporated with an auxiliary marker algorithm based on ResNet and Faster-RCNN(Faster Regions with Convolutional Neural Networks features). The binary classifier defines images with foreign objects such as balloons and kites as abnormal class, regardless the type, size, and number of the foreign objects in a single image. The auxiliary marker algorithm marks foreign objects in abnormal images, in order to provide additional help for quick location of hidden foreign objects. Our OTL-Classifier model achieves a recall rate of 95% and an error rate of 10.7% in the normal mode, and a recall rate of 100% and an error rate of 35.9% in the Warning–Review mode.
      Citation: Electronics
      PubDate: 2019-11-01
      DOI: 10.3390/electronics8111270
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1271: CMOS Voltage Reference using a
           Self-Cascode Composite Transistor and a Schottky Diode

    • Authors: Brito, Colombo, Moreno, El-Sankary
      First page: 1271
      Abstract: This work presents an investigation of the temperature behavior of self-cascode composite transistors (SCCTs). Results supported by silicon measurements show that SCCTs can be used to generate a proportional to absolute temperature voltage or even a temperature-compensated voltage. Based on the achieved results, a new circuit topology of a resistorless voltage reference circuit using a Schottky diode is also presented. The circuit was fabricated in a 130 nm BiCMOS process and occupied a silicon area of 67.98 µm × 161.7 µm. The averaged value of the output voltage is 720.4 mV, and its averaged line regulation performance is 2.3 mV/V, calculated through 26 characterized chip samples. The averaged temperature coefficient (TC) obtained through five chip samples is 56 ppm/°C in a temperature range from −40 to 85°C. A trimming circuit is also included in the circuit topology to mitigate the impact of the fabrication process effects on its TC. The circuit operates with a supply voltage range from 1.1 to 2.5 V.
      Citation: Electronics
      PubDate: 2019-11-01
      DOI: 10.3390/electronics8111271
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1272: An ANN-Based Temperature Controller for a
           Plastic Injection Moulding System

    • Authors: Khomenko, Veligorskyi, Chakirov, Vagapov
      First page: 1272
      Abstract: This paper proposes an approach to an ANN-based temperature controller design for a plastic injection moulding system. This design approach is applied to the development of a controller based on a combination of a classical ANN and integrator. The controller provides a fast temperature response and zero steady-state error for three typical heaters (bar, nozzle, and cartridge) for a plastic moulding system. The simulation results in Matlab Simulink software and in comparison to an industrial PID regulator have shown the advantages of the controller, such as significantly less overshoot and faster transient (compared to PID with autotuning) for all examined heaters. In order to verify the proposed approach, the designed ANN controller was implemented and tested using an experimental setup based on an STM32 board.
      Citation: Electronics
      PubDate: 2019-11-01
      DOI: 10.3390/electronics8111272
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1273: Decoding EEG in Motor Imagery Tasks with
           Graph Semi-Supervised Broad Learning

    • Authors: She, Zhou, Gan, Ma, Luo
      First page: 1273
      Abstract: In recent years, the accurate and real-time classification of electroencephalogram (EEG) signals has drawn increasing attention in the application of brain-computer interface technology (BCI). Supervised methods used to classify EEG signals have gotten satisfactory results. However, unlabeled samples are more frequent than labeled samples, so how to simultaneously utilize limited labeled samples and many unlabeled samples becomes a research hotspot. In this paper, we propose a new graph-based semi-supervised broad learning system (GSS-BLS), which combines the graph label propagation method to obtain pseudo-labels and then trains the GSS-BLS classifier together with other labeled samples. Three BCI competition datasets are used to assess the GSS-BLS approach and five comparison algorithms: BLS, ELM, HELM, LapSVM and SMIR. The experimental results show that GSS-BLS achieves satisfying Cohen’s kappa values in three datasets. GSS-BLS achieves the better results of each subject in the 2-class and 4-class datasets and has significant improvements compared with original BLS except subject C6. Therefore, the proposed GSS-BLS is an effective semi-supervised algorithm for classifying EEG signals.
      Citation: Electronics
      PubDate: 2019-11-01
      DOI: 10.3390/electronics8111273
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1274: Timing Criticality-Aware Design
           Optimization using BEOL Air Gap Technology on Consecutive Metal Layers

    • Authors: Ryu, Cho, Han
      First page: 1274
      Abstract: Air-gap (AG) technology on back-end-of-line (BEOL) provides a means to improve performance without area or power degradation. However, the “blind” use of AG based on traditional design methodologies does not provide sufficient performance gain. We developed an AG-aware design methodology to maximize performance gain with minimum cost. The experimental results of the proposed methodology, which was tested using a 10 nm Advanced RISC Machine (ARM) Cortex-A9 quad-core central processing unit (CPU), indicated a performance gain of 6.1–8.4% compared with traditional AG design. The performance gain achieved represents about half of the 10–15% performance improvement under the same power by a process node shrink. A Si process of consecutive double AG layers was developed by overcoming various process challenges, such as AG depth control, Cu/ultra-low-k damage, the hermetic AG liner, and step-height control above the AG. Furthermore, the capacitance was reduced by 17.0%, which satisfied the target goal in the simulation stage for the assumed structure. The optimized integration process was validated according to the function yield of the CPU, which was comparable to that of a non-AG process. The time-dependent dielectric breakdown and electromigration lifetime of the AG wire satisfied the 10-year criteria, and the assembly yield was verified.
      Citation: Electronics
      PubDate: 2019-11-01
      DOI: 10.3390/electronics8111274
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1275: A 40 nW CMOS-Based Temperature Sensor
           with Calibration Free Inaccuracy within ±0.6 ∘C

    • Authors: Shailesh Singh Chouhan, Kari Halonen
      First page: 1275
      Abstract: In this study, a temperature equivalent voltage signal was obtained by subtracting output voltages received from two individual temperature sensors. These sensors work in the subthreshold region and generate the output voltage signals that are proportional and complementary to the temperature. Over the temperature range of −40 ∘C to +85 ∘C without using any calibration method, absolute temperature inaccuracy less than ±0.6 ∘C was attained from the measurement of five prototypes of the proposed temperature sensor. The implementation was done in a standard 0.18 μ m CMOS technology with a total area of 0.0018 mm 2. The total power consumption is 40 nW for a supply voltage of 1.2 V measured at room temperature.
      Citation: Electronics
      PubDate: 2019-11-01
      DOI: 10.3390/electronics8111275
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1276: Mobile P2P-Based Skyline Query Processing
           over Delay-Tolerant Networks

    • Authors: Bok, Park, Lim, Yoo
      First page: 1276
      Abstract: Skyline query-processing techniques considering various properties in peer to peer (P2P)-based services have become a recent topic of research. In this paper, we propose a new skyline query-processing scheme to improve the query-processing performance and accuracy in a mobile P2P service over delay-tolerant networks. The proposed scheme collects data on the query object from neighboring nodes and establishes a local skyline through static properties to reduce query-processing costs. To improve the query accuracy in a non-uniform distribution environment, the query-dissemination range is expanded by enforcing a query-dissemination range expansion. The performance evaluation conducted to verify the superiority of the proposed scheme demonstrates that it has a better performance compared to the existing schemes.
      Citation: Electronics
      PubDate: 2019-11-02
      DOI: 10.3390/electronics8111276
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1277: A Multi-Column Deep Framework for
           Recognizing Artistic Media

    • Authors: Yang, Min
      First page: 1277
      Abstract: We present a multi-column structured framework for recognizing artistic media from artwork images. We design the column of our framework using a deep neural network. Our key idea is to recognize the distinctive stroke texture of an artistic medium, which plays a key role in distinguishing artistic media. Since stroke texture is in a local scale, the whole image is not proper for recognizing the texture. Therefore, we devise two ideas for our framework: Sampling patches from an input image and employing a Gram matrix to extract the texture. The patches sampled from an input artwork image are processed in the columns of our framework to make local decisions on the patch, and the local decisions from the patches are merged to make a final decision for the input artwork image. Furthermore, we employ a Gram matrix, which is known to effectively capture texture information, to improve the accuracy of recognition. Our framework is trained and tested using two real artwork image datasets: WikiSet of traditional artwork images and YMSet of contemporary artwork images. Finally, we build SynthSet, which is a collection of synthesized artwork images from many computer graphics literature, and propose a guideline for evaluating the synthesized artwork images.
      Citation: Electronics
      PubDate: 2019-11-02
      DOI: 10.3390/electronics8111277
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1278: Life Cycle Assessment of Lighting Systems
           and Light Loss Factor: A Case Study for Indoor Workplaces in France

    • Authors: Bertin, Canale, Ben Abdellah, Mequignon, Zissis
      First page: 1278
      Abstract: Life cycle assessment (LCA) methodology has been used to evaluate the performance of the following lighting systems: compact fluorescent lamps (CFL), light-emitting diode (LED) lamps, and fluorescent tubes (T5 type). This work covers the singularity of the French electricity mix for indoor workplaces lighting and describes the best strategy for lamp replacement. We have defined the light loss factor to integrate the following additional parameters: lumen depreciation, dirt accumulation, and risks of failure. Therefore, we propose a new definition of the functional unit (maintained megalumen hour), and we conduct this assessment to be compliant with the standards of lighting system equipment (NF EN 12464-1). Unlike previous studies, we observed that the manufacturing phase is the most impacting over the whole life cycle, thus making the extension of LED lamps’ lifetime a more effective strategy to reduce the potential environmental impacts than increasing their efficacy. This paper highlights how the light loss factor affects the LCA results and proves that it should be taken into account for subsequent assessments. Finally, this new approach includes the real usage of the lamps in the study and contributes to lay the foundation for life cycle sustainability assessment to also evaluate the economic, social, and human impacts of lighting.
      Citation: Electronics
      PubDate: 2019-11-02
      DOI: 10.3390/electronics8111278
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1279: Mesh-Grounded Monopolar Hexagonal
           Microstrip Antenna for Artillery-Launched Observation Round

    • Authors: Lee, Kim, Pyo
      First page: 1279
      Abstract: This paper presents a novel low-profile microstrip antenna with an omnidirectional radiation pattern for an artillery-launched observation round. The proposed antenna consists of one centered hexagonal patch for a feeding network and six periodic arrays of a trapezoid patch for a radiator. The trapezoid patch is equal to a half-sized hexagonal patch based on geometrical symmetry. A gap-coupled one-hexagonal patch and six trapezoid patches are supported on a nonfundamental TM02 mode for vertically polarized omnidirectional radiation patterns. In addition, a meshed ground structure for the proposed antenna is employed to improve the impedance bandwidth. The thin metal wires that are formed by the meshed ground structure yield six trapezoid slot arrays for the feeding network and three triangular slot arrays for the radiator on the ground plane. To verify the feasibility of the meshed ground structure, the mesh width, denoted by w, was investigated theoretically and optimized carefully to enlarge the impedance bandwidth of the proposed antenna. Finally, the proposed antenna, with a mesh width of 0.2 mm, successfully demonstrated excellent monopolar radiation at a resonant frequency of 5.84 GHz, a realized gain of 5.27 dBi, and an impedance bandwidth of 452 MHz from 5.583 GHz to 6.035 GHz with respect to 7.78% at a center frequency of 5.809 GHz.
      Citation: Electronics
      PubDate: 2019-11-03
      DOI: 10.3390/electronics8111279
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1280: Analysis of Propagation Characteristics
           along an Array of Silver Nanorods Using Dielectric Constants from
           Experimental Data and the Drude-Lorentz Model

    • Authors: Zong, Zhang
      First page: 1280
      Abstract: In this study, the Fourier series expansion method (FSEM) was employed to calculate the complex propagation constants of plasma structures consisting of infinitely long, silver nanorod arrays in the range of 180–1900 nm, and the characteristics of the complex propagation constant were analyzed in depth. According to the results of FSEM using dielectric constants from Johnson experimental data, a multi-mode frequency band appears in the propagation stage, which can be adopted to achieve a multi-mode communication, multi-mode transceiver, integrated filter with single multi-mode combination. In the meantime, the comparison between the three sets of results with only single mode transmission of the generalized multipole technique (GMT) using dielectric constants from Johnson experimental data, FSEM using dielectric constants from Palik experimental data, and FSEM using dielectric function from Drude–Lorentz model suggested that the results of the four sets of complex propagation constants were well consistent with each other. Furthermore, a finite array of only 40 silver nanorods was studied, and the ability of guided waves when a finite array is excited by a plane wave at a specific wavelength was explored. According to different guiding abilities—propagation, attenuation, and cut off, it can be applied to waveguides, sensor, filters, etc.
      Citation: Electronics
      PubDate: 2019-11-03
      DOI: 10.3390/electronics8111280
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1281: Insight on Electronic Travel Aids for
           Visually Impaired People: A Review on the Electromagnetic Technology

    • Authors: Emanuele Cardillo, Alina Caddemi
      First page: 1281
      Abstract: This review deals with a comprehensive description of the available electromagnetic travel aids for visually impaired and blind people. This challenging task is considered as an outstanding research area due to the rapid growth in the number of people with visual impairments. For decades, different technologies have been employed for solving the crucial challenge of improving the mobility of visually impaired people, but a suitable solution has not yet been developed. Focusing this contribution on the electromagnetic technology, the state-of-the-art of available solutions is demonstrated. Electronic travel aids based on electromagnetic technology have been identified as an emerging technology due to their high level of achievable performance in terms of accuracy, flexibility, lightness, and cost-effectiveness.
      Citation: Electronics
      PubDate: 2019-11-04
      DOI: 10.3390/electronics8111281
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1282: Evaluation of M-Payment Technology and
           Sectoral System Innovation—A Comparative Study of UK and Indian Models

    • Authors: Heather Webb, Shubo Liu, Min-Ren Yan
      First page: 1282
      Abstract: The paper constructs a sectoral system of innovation model specifically for the mobile payments (m-payments) sector. Both the UK and Indian sectoral system of innovation were studied in regards of the actors involved in providing the m-payment service with an emphasis on emergent business models. We integrated open innovation and Ogle’s ideas into our model and demonstrated the importance of active agency in shaping innovation systems, for example in leveraging existing social networks. The research draws upon original interviews with companies and regulators in both India and the UK. Our overall conclusion is that the m-payments sectoral system of innovation in India is more customer-oriented and far-reaching as compared to the practices in UK. It concludes that no matter the context, the importance of integrating firms’ activity into integrated service systems in demand-driven innovation is key for success.
      Citation: Electronics
      PubDate: 2019-11-04
      DOI: 10.3390/electronics8111282
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1283: Overview: Types of Lower Limb
           Exoskeletons

    • Authors: Daniel S Pamungkas, Wahyu Caesarendra, Hendawan Soebakti, Riska Analia, Susanto Susanto
      First page: 1283
      Abstract: Researchers have given attention to lower limb exoskeletons in recent years. Lower limb exoskeletons have been designed, prototype tested through experiments, and even produced. In general, lower limb exoskeletons have two different objectives: (1) rehabilitation and (2) assisting human work activities. Referring to these objectives, researchers have iteratively improved lower limb exoskeleton designs, especially in the location of actuators. Some of these devices use actuators, particularly on hips, ankles or knees of the users. Additionally, other devices employ a combination of actuators on multiple joints. In order to provide information about which actuator location is more suitable; a review study on the design of actuator locations is presented in this paper. The location of actuators is an important factor because it is related to the analysis of the design and the control system. This factor affects the entire lower limb exoskeleton’s performance and functionality. In addition, the disadvantages of several types of lower limb exoskeletons in terms of actuator locations and the challenges of the lower limb exoskeleton in the future are also presented in this paper.
      Citation: Electronics
      PubDate: 2019-11-04
      DOI: 10.3390/electronics8111283
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1284: Photographic Noise Performance Measures
           Based on RAW Files Analysis of Consumer Cameras

    • Authors: Jorge Igual
      First page: 1284
      Abstract: Photography is being benefited from the huge improvement in CMOS image sensors. New cameras extend the dynamic range allowing photographers to take photos with a higher quality than they could imagine one decade ago. However, the existence of different technologies make more complicated the photographic analysis of how to determine the optimal camera exposure settings. In this paper, we analyze how the different noise models are translated to different signal to noise S N R curve patterns and which factors are relevant. In particular, we discuss profoundly the relationships between exposure settings (shutter speed, aperture and ISO). Since a fair comparison between cameras can be tricky because of different pixel size, sensor format or ISO scale definition, we explain how the pixel analysis of a camera can be translated to a more helpful universal photographic noise measure based on human perception and common photography rules. We analyze the RAW files of different camera models and show how the noise performance analysis ( S N R and dynamic range) interact with photographer’s requirements.
      Citation: Electronics
      PubDate: 2019-11-04
      DOI: 10.3390/electronics8111284
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1285: An FPGA-Based 16-Bit Continuous-Time 1-1
           MASH ΔΣ TDC Employing Multirating Technique

    • Authors: Ahmad Mouri Zadeh Khaki, Ebrahim Farshidi, Sawal Hamid MD Ali, Masuri Othman
      First page: 1285
      Abstract: An all-digital voltage-controlled oscillator (VCO)-based second-order multi-stage noise-shaping (MASH) ΔΣ time-to-digital converter (TDC) is presented in this paper. The prototype of the proposed TDC was implemented on an Altera Stratix IV FPGA board. In order to improve the performance over conventional TDCs, a multirating technique is employed in this work in which higher sampling rate is used for higher stages. Experimental results show that the multirating technique had a significant influence on improving signal-to-noise ratio (SNR), from 43.09 dB without multirating to 61.02 dB with multirating technique (a gain of 17.93 dB) by quadrupling the sampling rate of the second stage. As the proposed design works in the time-domain and does not consist of any loop and calibration block, no time-to-voltage conversion is needed which results in low complexity and power consumption. A built-in oscillator and phase-locked loops (PLLs) of the FPGA board are utilized to generate sampling clocks at different frequencies. Therefore, no external clock needs to be applied to the proposed TDC. Two cases with different sampling rates were examined by the proposed design to demonstrate the capability of the technique. It can be implied that, by employing multirating technique and increasing sampling frequency, higher SNR can be achieved.
      Citation: Electronics
      PubDate: 2019-11-05
      DOI: 10.3390/electronics8111285
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1286: Online Slack-Stealing Scheduling with
           Modified laEDF in Real-Time Systems

    • Authors: Wonbo Jeon, Wonsop Kim, Heoncheol Lee, Cheol-Hoon Lee
      First page: 1286
      Abstract: In hard real-time task systems where periodic and aperiodic tasks coexist, the object of task scheduling is to reduce the response time of the aperiodic tasks while meeting the deadline of periodic tasks. Total bandwidth server (TBS) and advanced TBS (ATBS) are used in dynamic priority systems. However, these methods are not optimal solutions because they use the worst-case execution time (WCET) or the estimation value of the actual execution time of the aperiodic tasks. This paper presents an online slack-stealing algorithm called SSML that can make significant response time reducing by modification of look-ahead earliest deadline first (laEDF) algorithm as the slack computation method. While the conventional slack-stealing method has a disadvantage that the slack amount of each frame must be calculated in advance, SSML calculates the slack when aperiodic tasks arrive. Our simulation results show that SSML outperforms the existing TBS based algorithms when the periodic task utilization is higher than 60%. Compared to ATBS with virtual release advancing (VRA), the proposed algorithm can reduce the response time up to about 75%. The performance advantage becomes much larger as the utilization increases. Moreover, it shows a small performance variation of response time for various task environments.
      Citation: Electronics
      PubDate: 2019-11-05
      DOI: 10.3390/electronics8111286
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1287: Learning-Based Task Offloading for Marine
           Fog-Cloud Computing Networks of USV Cluster

    • Authors: Kuntao Cui, Bin Lin, Wenli Sun, Wenqiang Sun
      First page: 1287
      Abstract: In recent years, unmanned surface vehicles (USVs) have made important advances in civil, maritime, and military applications. With the continuous improvement of autonomy, the increasing complexity of tasks, and the emergence of various types of advanced sensors, higher requirements are imposed on the computing performance of USV clusters, especially for latency sensitive tasks. However, during the execution of marine operations, due to the relative movement of the USV cluster nodes and the network topology of the cluster, the wireless channel states are changing rapidly, and the computing resources of cluster nodes may be available or unavailable at any time. It is difficult to accurately predict in advance. Therefore, we propose an optimized offloading mechanism based on the classic multi-armed bandit (MAB) theory. This mechanism enables USV cluster nodes to dynamically make offloading decisions by learning the potential computing performance of their neighboring team nodes to minimize average computation task offloading delay. It is an optimized algorithm named Adaptive Upper Confidence Boundary (AUCB) algorithm, and corresponding simulations are designed to evaluate the performance. The algorithm enables the USV cluster to effectively adapt to the marine vehicular fog computing networks, balancing the trade-off between exploration and exploitation (EE). The simulation results show that the proposed algorithm can quickly converge to the optimal computation task offloading combination strategy under heavy and light input data loads.
      Citation: Electronics
      PubDate: 2019-11-05
      DOI: 10.3390/electronics8111287
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1288: A Prototype Photoplethysmography
           Electronic Device that Distinguishes Congestive Heart Failure from Healthy
           Individuals by Applying Natural Time Analysis

    • Authors: George Baldoumas, Dimitrios Peschos, Giorgos Tatsis, Spyridon K. Chronopoulos, Vasilis Christofilakis, Panos Kostarakis, Panayiotis Varotsos, Nicholas V. Sarlis, Efthimios S. Skordas, Aris Bechlioulis, Lampros K. Michalis, Katerina K. Naka
      First page: 1288
      Abstract: In this paper, a prototype photoplethysmography (PPG) electronic device is presented for the distinction of individuals with congestive heart failure (CHF) from the healthy (H) by applying the concept of Natural Time Analysis (NTA). Data were collected simultaneously with a conventional three-electrode electrocardiography (ECG) system and our prototype PPG electronic device from H and CHF volunteers at the 2nd Department of Cardiology, Medical School of Ioannina, Greece. Statistical analysis of the results show a clear separation of CHF from H subjects by means of NTA for both the conventional ECG system and our PPG prototype system, with a clearly better distinction for the second one which additionally inherits the advantages of a low-cost portable device.
      Citation: Electronics
      PubDate: 2019-11-05
      DOI: 10.3390/electronics8111288
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1289: Machine Learning in Resource-Scarce
           Embedded Systems, FPGAs, and End-Devices: A Survey

    • Authors: Sérgio Branco, André G. Ferreira, Jorge Cabral
      First page: 1289
      Abstract: The number of devices connected to the Internet is increasing, exchanging large amounts of data, and turning the Internet into the 21st-century silk road for data. This road has taken machine learning to new areas of applications. However, machine learning models are not yet seen as complex systems that must run in powerful computers (i.e., Cloud). As technology, techniques, and algorithms advance, these models are implemented into more computational constrained devices. The following paper presents a study about the optimizations, algorithms, and platforms used to implement such models into the network’s end, where highly resource-scarce microcontroller units (MCUs) are found. The paper aims to provide guidelines, taxonomies, concepts, and future directions to help decentralize the network’s intelligence.
      Citation: Electronics
      PubDate: 2019-11-05
      DOI: 10.3390/electronics8111289
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1290: A Novel Nonlinearity Correction Algorithm
           for FMCW Radar Systems for Optimal Range Accuracy and Improved Multitarget
           Detection Capability

    • Authors: Onur Toker, Marius Brinkmann
      First page: 1290
      Abstract: Frequency-modulated continuous wave (FMCW) radars are an important class of radar systems, and they are quite popular because of their simpler architecture and lower cost. A fundamental problem in FMCW radars is the nonlinearity of the voltage-controlled oscillator (VCO), which results in a range of measurement errors, problems in multitarget detection, and degradation in synthetic aperture radar (SAR) images. In this paper, we first introduce a novel upsampling theory, then propose new algorithms to improve range accuracy and multitarget detection capability. These improvements are demonstrated both by simulations and actual lab experiments on a 2.4 GHz radar system. There are several techniques reported in the literature for VCO nonlinearity correction, but what makes the proposed approach different is that we focus on real-time processing on low-cost hardware and optimize the design subject to this constraint. We first developed an optimal upsampling theory which is based on almost-causal finite impulse response (FIR) filters. Compared to the sinc-based noncausal interpolation-based upsamplers, the proposed approach is based on using interpolation filters with few number of coefficients. Furthermore, interpolators are trained for a specific class of signals rather than a highly general signal set. Therefore, the proposed approach can be implemented on lower-cost hardware and perform quite well compared to more expensive systems.
      Citation: Electronics
      PubDate: 2019-11-05
      DOI: 10.3390/electronics8111290
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1291: 3d Beam Reconfigurable THz Antenna with
           Graphene-Based High-Impedance Surface

    • Authors: Wang, Yao, Yu, Chen
      First page: 1291
      Abstract: : In this letter, a novel 3D multi-beam reconfigurable THz loop antenna capable of steering its main beam in the semi-sphere space (θ ϵ {0°, ±5°, ±10°}; φ ϵ {0°, 30°, 60°, 90°, 120°, 150°}) is presented. The antenna is based on a switchable circular high impedance surface (HIS) using the graphene–metal hybrid approach. The effect of gate voltage on the conductivity of graphene and the switchable reflection characteristic of the graphene-based HIS are combined in the design. Changing the chemical potential of different graphene-based HIS units can effectively adjust the beam direction. The performance of the antenna is analyzed through its reflection coefficients and gain radiation patterns, and simulated results show that the maximum gain can reach 3.23 dBi at 0.5 THz.
      Citation: Electronics
      PubDate: 2019-11-05
      DOI: 10.3390/electronics8111291
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1292: A New Rail-to-Rail Second Generation
           Voltage Conveyor

    • Authors: Barile, Stornelli, Ferri, Safari, D’Amico
      First page: 1292
      Abstract: In this paper, a novel low voltage low power CMOS second generation voltage conveyor (VCII) with an improved voltage range at both the X and Z terminals is presented. The proposed VCII is formed by a current buffer based on a class AB regulated common-gate stage and a modified rail-to-rail voltage buffer. Spice simulation results using LFoundry 0.15 μm low-Vth CMOS technology with a ±0.9 V supply voltage are provided to demonstrate the validity of the designed circuit. Thanks to the class AB behavior, from a bias current of 10 µA, the proposed VCII is capable of driving 0.5 mA on the X terminal, with a total power consumption of 120 µW. The allowed voltage swing on the Z terminal is at least equal to ±0.83 V, while on the X terminals it is ±0.72 V. Both DC and AC voltage and current gains are provided, and time domain simulations, where the voltage conveyor is used as a transimpedance amplifier (TIA), are also presented. A final table that summarizes the main features of the circuit, comparing them with the literature, is also given.
      Citation: Electronics
      PubDate: 2019-11-05
      DOI: 10.3390/electronics8111292
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1293: A Regulated Charge Pump with Extremely
           Low Output Ripple

    • Authors: Mir Mohammad Navidi, David W. Graham
      First page: 1293
      Abstract: In this paper, we present a regulated charge pump with extremely low output ripple (<1 mV) that can be used for accurate programming of nonvolatile memory. We present a technique to include a low-drop-out regulator inside the charge-pump regulation loop to reduce the ripple. This charge pump was fabricated in a 0.35 μ m standard CMOS process. The die area of this charge pump is 0.163 mm 2 . While operating from a 2.5 V supply, this charge pump generates regulated voltages up to 10 V.
      Citation: Electronics
      PubDate: 2019-11-06
      DOI: 10.3390/electronics8111293
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1294: Different Antenna Designs for Non-Contact
           Vital Signs Measurement: A Review

    • Authors: Carolina Gouveia, Caroline Loss, Pedro Pinho, José Vieira
      First page: 1294
      Abstract: Cardiopulmonary activity measured through contactless means is a hot topic within the research community. The Doppler radar is an approach often used to acquire vital signs in real time and to further estimate their rates, in a remote way and without requiring direct contact with subjects. Many solutions have been proposed in the literature, using different transceivers and operation modes. Nonetheless, all different strategies have a common goal: enhance the system efficiency, reduce the manufacturing cost, and minimize the overall size of the system. Antennas are a key component for these systems since they can influence the radar robustness directly. Therefore, antennas must be designed with care, facing several trade-offs to meet all the system requirements. In this sense, it is necessary to define the proper guidelines that need to be followed in the antenna design. In this manuscript, an extensive review on different antenna designs for non-contact vital signals measurements is presented. It is intended to point out and quantify which parameters are crucial for the optimal radar operation, for non-contact vital signs’ acquisition.
      Citation: Electronics
      PubDate: 2019-11-06
      DOI: 10.3390/electronics8111294
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1295: Open Vision System for Low-Cost Robotics
           Education

    • Authors: Julio Vega, José M. Cañas
      First page: 1295
      Abstract: Vision devices are currently one of the most widely used sensory elements in robots: commercial autonomous cars and vacuum cleaners, for example, have cameras. These vision devices can provide a great amount of information about robot surroundings. However, platforms for robotics education usually lack such devices, mainly because of the computing limitations of low cost processors. New educational platforms using Raspberry Pi are able to overcome this limitation while keeping costs low, but extracting information from the raw images is complex for children. This paper presents an open source vision system that simplifies the use of cameras in robotics education. It includes functions for the visual detection of complex objects and a visual memory that computes obstacle distances beyond the small field of view of regular cameras. The system was experimentally validated using the PiCam camera mounted on a pan unit on a Raspberry Pi-based robot. The performance and accuracy of the proposed vision system was studied and then used to solve two visual educational exercises: safe visual navigation with obstacle avoidance and person-following behavior.
      Citation: Electronics
      PubDate: 2019-11-06
      DOI: 10.3390/electronics8111295
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1296: Current Source AC-Side Clamped Inverter
           for Leakage Current Reduction in Grid-Connected PV System

    • Authors: Li, Wang, San, Guo
      First page: 1296
      Abstract: For the grid-connected photovoltaic inverters, the switching-frequency common-mode voltage brings the leakage current, which should be eliminated. So far, many kinds of single-phase inverters have been published for this purpose, but most of them are the conventional voltage-type ones, which have the disadvantages of poor reliability due to the DC-link electrolytic capacitor and the risk of short-through of the bridge switches. To solve this technical issue, a novel current source inverter with AC-side clamping is proposed to mitigate the switching-frequency common-mode voltage. Meanwhile, a novel modulation method is proposed for the new single-phase inverter to achieve low-frequency operation of the main switches, which reduces the switching losses. Finally, the proposed method is implemented on the TMS320F28335DSP + XC6SLX9FPGA digital hardware platform. Also, the performance comparisons are done with the traditional solution. The results prove the proposed solution.
      Citation: Electronics
      PubDate: 2019-11-06
      DOI: 10.3390/electronics8111296
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1297: Downlink Power Allocation Strategy for
           Next-Generation Underwater Acoustic Communications Networks

    • Authors: Ahmad, Chang
      First page: 1297
      Abstract: The increasing interest in next-generation underwater acoustic communications networks is due to vast investigation of oceans for oceanography, commercial operations in maritime areas, military surveillance, and more. A surface buoy or underwater base station controller (UBSC) communicates with either transceivers or underwater base stations (UBSs) via acoustic links. Transceivers further communicate with underwater sensor nodes using acoustic links. In this paper, we employ a downlink (DL) power allocation (PA) strategy using an orthogonal frequency-division multiple access (OFDMA) technique for underwater acoustic communications (UAC) networks. First, we present an approach to power offsets using three kinds of pilot spacing and apply the power boosting (PB) concept on orthogonal frequency-division multiplexing (OFDM) symbols for the UAC network. Secondly, we draw the block error rate (BLER) curves from link-level simulation (LLS) and analyze the signal-to-noise ratio (SNR) for both PA and non-PA strategies. Lastly, we adopt the best PB for system-level simulation (SLS) and compare the throughput and outage performance for PA and non-PA strategies. Hence, the simulation results confirm the effectiveness of the DL PA strategy for UAC networks.
      Citation: Electronics
      PubDate: 2019-11-06
      DOI: 10.3390/electronics8111297
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1298: Visual Servoing in Robotics

    • Authors: Pomares
      First page: 1298
      Abstract: Visual servoing is a well-known approach to guide robots using visual information[...]
      Citation: Electronics
      PubDate: 2019-11-06
      DOI: 10.3390/electronics8111298
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1299: A Trust Framework to Detect Malicious
           Nodes in Cognitive Radio Networks

    • Authors: Geetanjali Rathee, Farhan Ahmad, Chaker A. Kerrache, Muhammad Ajmal Azad
      First page: 1299
      Abstract: Cognitive radio is considered as a pioneering technique in the domain of wireless communication as it enables and permits the Cognitive Users (CU) to exploit the unused channels of the Primary Users (PU) for communication and networking. The CU nodes access the vacant bands/channels through the Cognitive Radio Network (CRN) cycle by executing its different phases, which are comprised of sensing, decision making, sharing (accessing) and hand-off (mobility). Among these phases, hand-off is the most critical phase as the CU needs to switch its current data transmissions to another available channel by recalling all the previous functions upon the emergence of a PU. Further, from the security perspective, a Malicious User (MU) may imitate the PU signal with the intention to never allow the CU to use its idle band, which ultimately degrades the overall network performance. Attacks such as the Cognitive User Emulation Attack (CUEA) and Primary User Emulation Attack (PUEA) may be encountered by the handoff procedure, which need to be resolved. To address this issue, a secure and trusted routing and handoff mechanism is proposed specifically for the CRN environment, where malicious devices are identified at the lower layers, thus prohibiting them from being part of the communication network. Further, at the network layer, users need to secure their data that are transmitted through various intermediate nodes. To ensure a secure handoff and routing mechanism, a Trust Analyser (TA) is introduced between the CU nodes and network layer. The TA maintains the record of all the communicating nodes at the network layer while also computing the rating and trust value of the Handoff Cognitive User (HCUs) using the Social Impact Theory Optimizer (SITO). The simulation results suggest that the proposed solution leads to 88% efficiency in terms of better throughput of CRN during data communication, the packet loss ratio, the packet delivery ratio and the maximum and average authentication delay and clearly outperforms the prevailing mechanisms in all the parameters.
      Citation: Electronics
      PubDate: 2019-11-07
      DOI: 10.3390/electronics8111299
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1300: Arm-ECG Wireless Sensor System for
           Wearable Long-Term Surveillance of Heart Arrhythmias

    • Authors: Angel Villegas, David McEneaney, Omar Escalona
      First page: 1300
      Abstract: This article presents the devising, development, prototyping and assessment of a wearable arm-ECG sensor system (WAMECG1) for long-term non-invasive heart rhythm monitoring, and functionalities for acquiring, storing, visualizing and transmitting high-quality far-field electrocardiographic signals. The system integrates the main building blocks present in a typical ECG monitoring device such as the skin surface electrodes, front-end amplifiers, analog and digital signal conditioning filters, flash memory and wireless communication capability. These are integrated into a comfortable, easy to wear, and ergonomically designed arm-band ECG sensor system which can acquire a bipolar ECG signal from the upper arm of the user over a period of 72 h. The small-amplitude bipolar arm-ECG signal is sensed by a reusable, long-lasting, Ag–AgCl based dry electrode pair, then digitized using a programmable sampling rate in the range of 125 to 500 Hz and transmitted via Wi-Fi. The prototype comparative performance assessment results showed a cross-correlation value of 99.7% and an error of less than 0.75% when compared to a reference high-resolution medical-grade ECG system. Also, the quality of the recorded far-field bipolar arm-ECG signal was validated in a pilot trial with volunteer subjects from within the research team, by wearing the prototype device while: (a) resting in a chair; and (b) doing minor physical activities. The R-peak detection average sensibilities were 99.66% and 94.64%, while the positive predictive values achieved 99.1% and 92.68%, respectively. Without using any additional algorithm for signal enhancement, the average signal-to-noise ratio (SNR) values were 21.71 and 18.25 for physical activity conditions (a) and (b) respectively. Therefore, the performance assessment results suggest that the wearable arm-band prototype device is a suitable, self-contained, unobtrusive platform for comfortable cardiac electrical activity and heart rhythm logging and monitoring.
      Citation: Electronics
      PubDate: 2019-11-07
      DOI: 10.3390/electronics8111300
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1301: Incremental Low Rank Noise Reduction for
           Robust Infrared Tracking of Body Temperature during Medical Imaging

    • Authors: Bardia Yousefi, Hossein Memarzadeh Sharifipour, Mana Eskandari, Clemente Ibarra-Castanedo, Denis Laurendeau, Raymond Watts, Matthieu Klein, Xavier P. V. Maldague
      First page: 1301
      Abstract: Thermal imagery for monitoring of body temperature provides a powerful tool to decrease health risks (e.g., burning) for patients during medical imaging (e.g., magnetic resonance imaging). The presented approach discusses an experiment to simulate radiology conditions with infrared imaging along with an automatic thermal monitoring/tracking system. The thermal tracking system uses an incremental low-rank noise reduction applying incremental singular value decomposition (SVD) and applies color based clustering for initialization of the region of interest (ROI) boundary. Then a particle filter tracks the ROI(s) from the entire thermal stream (video sequence). The thermal database contains 15 subjects in two positions (i.e., sitting, and lying) in front of thermal camera. This dataset is created to verify the robustness of our method with respect to motion-artifacts and in presence of additive noise (2–20%—salt and pepper noise). The proposed approach was tested for the infrared images in the dataset and was able to successfully measure and track the ROI continuously (100% detecting and tracking the temperature of participants), and provided considerable robustness against noise (unchanged accuracy even in 20% additive noise), which shows promising performance.
      Citation: Electronics
      PubDate: 2019-11-07
      DOI: 10.3390/electronics8111301
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1302: Unstable System Control Using an Improved
           Particle Swarm Optimization-Based Neural Network Controller

    • Authors: Cheng-Jian Lin, Xin-You Lin, Jyun-Yu Jhang
      First page: 1302
      Abstract: In this study, an improved particle swarm optimization (IPSO)-based neural network controller (NNC) is proposed for solving a real unstable control problem. The proposed IPSO automatically determines an NNC structure by a hierarchical approach and optimizes the parameters of the NNC by chaos particle swarm optimization. The proposed NNC based on an IPSO learning algorithm is used for controlling a practical planetary train-type inverted pendulum system. Experimental results show that the robustness and effectiveness of the proposed NNC based on IPSO are superior to those of other methods.
      Citation: Electronics
      PubDate: 2019-11-07
      DOI: 10.3390/electronics8111302
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1303: Cell Voltage Equalizer Using a Selective
           Voltage Multiplier with a Reduced Selection Switch Count for
           Series-Connected Energy Storage Cells

    • Authors: Masatoshi Uno, Teruhisa Ueno, Koji Yoshino
      First page: 1303
      Abstract: Cell voltage equalization is mandatory to eliminate voltage imbalance of series-connected energy storage cells, such as lithium-ion batteries (LIBs) and electric double-layer capacitors (EDLCs), to ensure years of safe operations. Although a variety of cell equalizers using selection switches have been proposed, conventional techniques require numerous switches in proportion to the cell count and are prone to complexity. This paper proposes a novel cell voltage equalizer using a selective voltage multiplier. By embedding selection switches into the voltage multiplier-based cell voltage equalizer, the number of selection switches can be reduced in comparison with that in conventional topologies, realizing the simplified circuit. A prototype for twelve cells was built, and an equalization test using LIBs was performed. The voltage imbalance decreased down to approximately 20 mV by the proposed equalizer, and the standard deviation of cell voltages at the end of the equalization test was as low as 10 mV, demonstrating its equalization performance.
      Citation: Electronics
      PubDate: 2019-11-07
      DOI: 10.3390/electronics8111303
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1304: A Systematic Review of Performance
           Analysis in Rowing Using Inertial Sensors

    • Authors: Worsey, Espinosa, Shepherd, Thiel
      First page: 1304
      Abstract: Sporting organizations such as professional clubs and national sport institutions are constantly seeking novel training methodologies in an attempt to give their athletes a cutting edge. The advent of microelectromechanical systems (MEMS) has facilitated the integration of small, unobtrusive wearable inertial sensors into many coaches’ training regimes. There is an emerging trend to use inertial sensors for performance monitoring in rowing; however, the use and selection of the sensor used has not been appropriately reviewed. Previous literature assessed the sampling frequency, position, and fixing of the sensor; however, properties such as the sensor operating ranges, data processing algorithms, and validation technology are left unevaluated. To address this gap, a systematic literature review on rowing performance monitoring using inertial-magnetic sensors was conducted. A total of 36 records were included for review, demonstrating that inertial measurements were predominantly used for measuring stroke quality and the sensors were used to instrument equipment rather than the athlete. The methodology for both selecting and implementing technology appeared ad hoc, with no guidelines for appropriate analysis of the results. This review summarizes a framework of best practice for selecting and implementing inertial sensor technology for monitoring rowing performance. It is envisaged that this review will act as a guide for future research into applying technology to rowing.
      Citation: Electronics
      PubDate: 2019-11-07
      DOI: 10.3390/electronics8111304
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1305: Technical and Economic Assessment of
           VSC-HVDC Transmission Model: A Case Study of South-Western Region in
           Pakistan

    • Authors: Mehr Gul, Nengling Tai, Wentao Huang, Muhammad Haroon Nadeem, Muhammad Ahmad, Moduo Yu
      First page: 1305
      Abstract: The southwestern part of Pakistan is still not connected to the national grid, despite its abundance in renewable energy resources. However, this area becomes more important for energy projects due to the development of the deep-sea Gwadar port and the China Pakistan Economic Corridor (CPEC). In this paper, a voltage source converter (VSC) based high voltage DC (HVDC) transmission model is proposed to link this area to the national gird. A two-terminal VSC-HVDC model is used as a case study, in which a two-level converter with standard double-loop control is employed. The proposed model has a capacity of transferring bulk power of 3500 MW at 350 kV from Gwadar to Matiari. Furthermore, the discounted cash flow analysis of VSC-HVDC against the HVAC system shows that the proposed system is economically sustainable. The outcomes of this study reveal that the implementation of this project can bring economic stability and energy security in the southwestern region.
      Citation: Electronics
      PubDate: 2019-11-07
      DOI: 10.3390/electronics8111305
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1306: On Inferring Intentions in Shared Tasks
           for Industrial Collaborative Robots

    • Authors: Alberto Olivares-Alarcos, Sergi Foix, Guillem Alenyà
      First page: 1306
      Abstract: Inferring human operators’ actions in shared collaborative tasks plays a crucial role in enhancing the cognitive capabilities of industrial robots. In all these incipient collaborative robotic applications, humans and robots not only should share space, but also forces and the execution of a task. In this article, we present a robotic system that is able to identify different human’s intentions and to adapt its behavior consequently, only employing force data. In order to accomplish this aim, three major contributions are presented: (a) a force based operator’s intention recognition system based on data from only two users; (b) a force based dataset of physical human–robot interaction; and (c) validation of the whole system with 15 people in a scenario inspired by a realistic industrial application. This work is an important step towards a more natural and user-friendly manner of physical human–robot interaction in scenarios where humans and robots collaborate in the accomplishment of a task.
      Citation: Electronics
      PubDate: 2019-11-07
      DOI: 10.3390/electronics8111306
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1307: Design and Emulation of All-Digital
           Phase-Locked Loop on FPGA

    • Authors: Saichandrateja Radhapuram, Takuya Yoshihara, Toshimasa Matsuoka
      First page: 1307
      Abstract: This paper demonstrates the design and implementation of an all-digital phase-lockedloop (ADPLL) on Field Programmable Gate Array (FPGA). It is useful as an emulation techniqueto show the feasibility and effectiveness of the ADPLL in the early design stage. A D-S modulator(DSM, Delta-Sigma Modulator)-based digitally controlled ring-oscillator (ring-DCO) design, whichis fully synthesizable in Verilog HDL, is presented. This ring-DCO has fully digital control andfractional tuning range using the DSM. The ring-DCO does not contain library-specific cells andcan be synthesized independently of the standard cell library, thus making the design portable andreducing the time required to fit for different semiconductor processes considerably. Implementedring-DCO has a wide tuning range and high-frequency resolution which meet the demands ofsystem-level integration. The ADPLL implemented in this work has the characteristics of designflexibility, a wide range of working frequency from 120 MHz to 300 MHz, and a fast responsefor achieving a locked state. The proposed ADPLL can be easily ported to different processes ina short time. The design adaptation cost is limited to adjustment of loop parameters in the code.Thus, it can reduce the design time and design complexity of the ADPLL, making it very suitable forSystem-on-Chip (SoC) applications.
      Citation: Electronics
      PubDate: 2019-11-07
      DOI: 10.3390/electronics8111307
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1308: Implementation of Grading Method for
           Gambier Leaves Based on Combination of Area, Perimeter, and Image
           Intensity Using Backpropagation Artificial Neural Network

    • Authors: Rusydi, Anandika, Rahmadya, Fahmy, Rusydi
      First page: 1308
      Abstract: Gambier leaves are widely used in cosmetics, beverages, and medicine. Tarantang village in West Sumatera, Indonesia, is famous for its gambier commodity. Farmers usually classify gambier leaves by area and color. They inherit this ability through generations. This research creates a tool to imitate the skill of the farmers to classify gambier leaves. The tool is a box covered from outside light. Two LEDs are attached inside the box to get maintain light intensity. A camera is used to capture the leaf image and a raspberry Pi processes the leaf features. A mini monitor is provided to operate the system. Six hundred and twenty-five gambier leaves were classified into five grades. Leaves categorized into grades 1, 2, and 3 are forbidden to be picked. Grade 4 leaves are allowed to be picked and those in grade 5 are the recommended ones for picking. Leaf features are area, perimeter, and intensity of leaf image. Three artificial neural networks are developed based on each feature. One thousand leaf images were used for training and 500 leaf images were used for testing. The accuracies of the features are about 93%, 96% and 97% for area, perimeter and intensity, respectively. A combination of rules are introduced into the system based on the feature accuracy. Those rules can give 100% accuracy compared to the farmer’s recommendation. A real time application to classify the leaves could provide classification with the same decision result as the classifying performed by the farmers.
      Citation: Electronics
      PubDate: 2019-11-07
      DOI: 10.3390/electronics8111308
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1309: Power Efficient Current Driver Based on
           Negative Boosting for High-Speed Lasers

    • Authors: Saad Arslan, Syed Asmat Ali Shah, HyungWon Kim
      First page: 1309
      Abstract: Vertical-cavity surface-emitting lasers (VCSELs) are commonly used in high-speed optical communication and 3D sensing applications. Both of these applications require high switching frequency and a short rise time of the VCSEL current. The parasitic inductance of the wire (connecting the driver with VCSEL) makes it challenging to achieve a short rise time, which often incur increased supply voltage and excessive power consumption. This paper utilizes a momentary boosting in supply voltage to overcome the parasitic inductance of the wire with minimal power overhead. The proposed technique uses a precalculated boosting capacitance to produce negative voltage for common-anode VCSELs. The boosting capacitance provides the required amount of charge during the rising transition and automatically disconnects itself in steady-state. Circuit simulations reveal up to three times shorter rise time at the negligible cost of less than 10% power overhead.
      Citation: Electronics
      PubDate: 2019-11-08
      DOI: 10.3390/electronics8111309
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1310: Hall-Effect Current Sensors
           Susceptibility to EMI: Experimental Study

    • Authors: Orazio Aiello
      First page: 1310
      Abstract: The paper deals with the susceptibility to Electromagnetic Interference (EMI) of Hall-effect current sensors. They are usually employed in power systems because of their galvanic isolation. The EMI robustness of such contactless device was compared with that of resistive current sensing (wired method). To this purpose, a printed circuit board (PCB) was fabricated. EMI tests methods such as Bulk Current Injection (BCI), Transverse-Electromagnetic (TEM) cell and Direct Power injection (DPI) were performed to evaluate the robustness of the Hall-Effect current sensor. EMI-induced failures are highlighted by comparing the different measurements tests and setups.
      Citation: Electronics
      PubDate: 2019-11-08
      DOI: 10.3390/electronics8111310
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1311: A Novel 3D Visible Light Positioning
           Method Using Received Signal Strength for Industrial Applications

    • Authors: Yousef Almadani, Muhammad Ijaz, Wout Joseph, Sander Bastiaens, Sujan Rajbhandari, Bamidele Adebisi, David Plets
      First page: 1311
      Abstract: In this paper, a novel three-dimensional (3D) indoor visible light positioning (VLP) algorithm using the Cayley–Menger determinant (CMD) with a cost function is proposed and experimentally tested to track a drone for industrial applications. The proposed algorithm uses optical received signal strength (RSS) for estimating the drone’s 3D position without prior knowledge of its height. This reduces the need for additional height sensors used in some 3D VLP systems. The performance of the proposed algorithm in terms of positioning error is also compared with a linear least squares (LLS) trilateration algorithm, with and without tilting of the receiver and with multipath reflections. The simulation results show that the proposed algorithm is more accurate and outperforms the LLS algorithm by a median improvement of 21% and is also more robust to the effect of tilting, as well as in the presence of multipath reflections. Furthermore, the proposed algorithm has been experimentally tested and compared with the LLS algorithm in a VLP test bed measuring 4 × 4 × 4.1 m 3 . The experimental results show that the median errors for LLS are 11.4 cm, while the median errors for CMD are 10.5 cm, which results in an error decrease of 8% when CMD with a cost function is used.
      Citation: Electronics
      PubDate: 2019-11-08
      DOI: 10.3390/electronics8111311
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1312: X-Band High-Efficiency Continuous Class B
           Power Amplifier GaN MMIC Assisted by Input Second-Harmonic Tuning

    • Authors: Chen Jin, Yuan Gao, Wei Chen, Jianhua Huang, Zhiyu Wang, Jiongjiong Mo, Faxin Yu
      First page: 1312
      Abstract: This paper presents a high-efficiency continuous class B power amplifier MMIC (Monolithic Microwave Integrated Circuit) from 8 GHz to 10.5 GHz, fabricated with 0.25 μm GaN-on-SiC technology. The Pedro load-line method was performed to calculate the optimum load of the GaN field-effect transistor (FET) for efficiency enhancement. Optimized by an output second-harmonic tuned network, fundamental to second-harmonic impedance, mapping was established point-to-point within a broad frequency band, which approached the classic continuous class B mode with an expanded high-efficiency bandwidth. Moreover, the contribution to the output capacitance of the FET was introduced into the output second-harmonic tuned network, which simplified the structure of the output matching network. Assisted by the second-harmonic source-pull technique, the input second-harmonic tuned network was optimized to improve the efficiency of the power amplifier over the operation band. The measurement results showed 51–59% PAE (Power Added Efficiency) and 19.8–21.2 dB power gain with a saturated power of 40.8–42.2 dBm from 8 GHz to 10.5 GHz. The size of the chip was 3.2 × 2.4 mm2.
      Citation: Electronics
      PubDate: 2019-11-08
      DOI: 10.3390/electronics8111312
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1313: Auditory Perception Based Anti-Spoofing
           System for Human Age Verification

    • Authors: Muhammad Ilyas, Alice Othmani, Régis Fournier, Amine Nait-ali
      First page: 1313
      Abstract: Biometric systems are considered an efficient component for identification in the developing modern technologies. The aim of biometric systems is to verify or determine the identity of a user through his/her biological and behavioral characteristics. The threat of spoof attacks is always an important issue in biometric verification and authentication, which requires an updated and stronger protection system. In this article, we propose an anti-spoofing system based on auditory perception responses. To the best of our knowledge, this is the first time that an auditory perception based anti-spoofing system has been presented for age verification. The proposed auditory perception based anti-spoofing system was evaluated with 770 trials conducted by many subjects of each gender and age range (12–65 years of age). The results achieved are encouraging, as the auditory perception based system showed the lowest Equal Error Rate (EER) value of 5.5%.
      Citation: Electronics
      PubDate: 2019-11-08
      DOI: 10.3390/electronics8111313
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1314: A Unified Multimode Control of a DC–DC
           Interlinking Converter Integrated into a Hybrid Microgrid

    • Authors: Oswaldo López-Santos, Yeison Alejandro Aldana-Rodríguez, Germain Garcia, Luis Martínez-Salamero
      First page: 1314
      Abstract: DC–DC interlinking converters (ILCs) allow bidirectional energy exchange between DC buses of different voltage levels in microgrids. This paper introduces a multimode control approach of a half-bridge DC–DC converter interlinking an extra-low-voltage DC (ELVDC) bus of 48 VDC and a low-voltage DC (LVDC) bus of 240 VDC within a hybrid microgrid. By using the proposed control, the converter can transfer power between the buses when the other converters regulate them, or it can ensure the voltage regulation of one of the buses, this originating from its three operation modes. The proposed control scheme is very simple and provides a uniform system response despite the dependence of the converter dynamic on the operating point and the selected mode. Simulation and experimental results validated the theoretical development and demonstrated the usefulness of the proposed scheme.
      Citation: Electronics
      PubDate: 2019-11-08
      DOI: 10.3390/electronics8111314
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1315: Application of Reservoir Computing for
           the Modeling of Nano-Contact Vortex Oscillator

    • Authors: Ali Rida Ismail, Slavisa Jovanovic, Sébastien Petit-Watelot, Hassan Rabah
      First page: 1315
      Abstract: The Nano-Contact Vortex Oscillator (NCVO) is a highly nonlinear spintronic device that can depict chaotic and nonchaotic behaviors according to the current flowing through it. The potential use of such a device in the future-generation computing systems requires the knowledge of a realistic model capable of describing its exact dynamics. In this paper, we firstly investigate the behavior of NCVO based on the power spectral analysis. Furthermore, we propose and demonstrate two efficient approaches of reservoir computing for the modeling of such a device. The performances of the proposed models are addressed in two ways. First, the generated time-varying signals are compared with the simulated magnetizations of the NCVO at different operating currents. Then, the power spectral analysis of one of the two models is carried out to examine its overall behavior over the complete DC current operating range and its ability to diagnose chaotic and non-chaotic regimes. The proposed models show quite promising results that can be counted on for further research.
      Citation: Electronics
      PubDate: 2019-11-08
      DOI: 10.3390/electronics8111315
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1316: An Ultra-Wideband Bandpass Filter with a
           Notch Band and Wide Upper Bandstop Performances

    • Authors: Min-Hang Weng, Che-Wei Hsu, Siang-Wen Lan, Ru-Yuan Yang
      First page: 1316
      Abstract: This paper presents an ultra-wideband bandpass filter (UWB-BPF) with a notch band and a wide upper stopband. Two pairs of half-wavelength high-impedance line resonators tightly and strongly coupled to the input/output lines are used to provide the wideband responses. The first UWB responses of 3.4–5.0 GHz and the second UWB of 6.0–10.0 GHz are designed independently first and then combined together for the application of a direct-sequence ultra-wideband bandpass (DS-UWB) system. Without using any extra bandstop structure, a notch band at 5.2 GHz can be obtained. The fabricated UWB-BPF with a compact circuit size exhibits good passband performances including insertion losses of 1 ± 0.3 and 2 ± 0.4 dB for first and second passbands, respectively, a high isolation at 5.2 GHz with an attenuation level of 22.7 dB, and wide upper stopband responses from 11 GHz to 19 GHz, simultaneously. The measured results also exhibit good agreement with the simulated results.
      Citation: Electronics
      PubDate: 2019-11-08
      DOI: 10.3390/electronics8111316
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1317: A Ruggedness Improved Mobile Radio
           Frequency Power Amplifier Module with Dynamic Impedance Correction by
           Software Defined Atomization

    • Authors: Jooyoung Jeon, Myounggon Kang
      First page: 1317
      Abstract: A ruggedness improved multi-band radio frequency (RF) power amplifier (PA) module applicable to mobile handsets, which are required to survive against a serious load impedance change under extreme power and bias conditions, is presented. In this method, the load impedance of PA is adaptively adjusted with a digitally controlled impedance corrector to keep the PA safe by performing a load mismatch detection. The impedance mismatch detector, impedance corrector, and other RF switches were all integrated into a single integrated circuit (IC) using silicon on insulator (SOI) complementary metal oxide semiconductor (CMOS). For the verification purpose, a 2-stage hetero junction bipolar transistor (HBT) PA module adopting this method was fabricated. At a frequency of 1915 MHz, a collector bias voltage of 4.2 V, and over a wider range of load impedance variation between a VSWR of 1 and a VSWR of 5.5, it did not fail. When this technique was not applied with a voltage standing wave ratio (VSWR) range of 1 to 4, it resulted in an acceptable RF performance degradation of 1% power added efficiency (PAE) in envelope tracking (ET) mode. Moreover, it survived at a bias voltage 1V larger than when the technique was not applied for the same mismatch condition.
      Citation: Electronics
      PubDate: 2019-11-08
      DOI: 10.3390/electronics8111317
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1318: 5G Base Station Deployment Perspectives
           in Millimeter Wave Frequencies using Meta-Heuristic Algorithms

    • Authors: Ganame, Yingzhuang, Ghazzai, Kamissoko
      First page: 1318
      Abstract: It can be predicted that the infrastructure of the existing wireless networks will not fill the requirement of the fifth generation (5G) wireless network due to the high data rates and a large number of expected traffic. Thus, a novel deployment method is crucial to satisfy 5G features. Meta-heuristic is expected to be a promising method for the complex deployment optimization problem of the 5G network. This work presents an implementation of a meta-heuristic algorithm based on swarm intelligence, to minimize the number of base stations (BSs) and optimize their placements in millimeter wave (mmWave) frequencies (e.g., 28 GHz and 38 GHz) in the context of the 5G network while satisfying user data rates requirement. Then, an iterative method is applied to remove redundant BSs. We formulate an optimization problem that takes into account multiple 5G network deployment scenarios. Further, a comparative study is conducted with the well-known simulated annealing (SA) using Monte Carlo simulations to assess the performance of the developed model. In our simulation results, we divide the region of interest into two subareas with different user distributions for different network scenarios while considering the intercell interference. The results demonstrate that the proposed approach has better network coverage with low percentage users in outage. In addition, the developed approach has less computational times to reach the desired target network quality of service (QoS).
      Citation: Electronics
      PubDate: 2019-11-08
      DOI: 10.3390/electronics8111318
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1319: A CMOS Transmitter Analog Baseband for 5G
           Mobile Communication

    • Authors: Yen, Chen, Wei, Chung
      First page: 1319
      Abstract: CMOS analog baseband circuits including a low-pass filter (LPF) and a programmable gain amplifier (PGA) are designed and implemented for the fifth-generation (5G) mobile communication. The super source follower topology is adopted to achieve a wideband LPF with good linearity, while the constant current density gain control technique is used to implement gain cells of the PGA. The circuits are integrated as an analog baseband for a 5G transmitter (TX) and fabricated using TSMC 90-nm CMOS technology. The analog baseband exhibits the bandwidth from 1.03 to 1.05 GHz when the voltage gain is varied from −18.9 dB to 3.8 dB in 1-dB steps. The gain step errors are within −0.7 dB to 0.9 dB. In the highest gain mode, the analog baseband achieves the IP1dB of −10 dBv and the IIP3 of −0.2 dBv. Over the band of interest, the NF of the analog baseband is 24.4–40.0 dB.
      Citation: Electronics
      PubDate: 2019-11-08
      DOI: 10.3390/electronics8111319
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1320: Magnetic Loss Analysis in Coaxial
           Magnetic Gears

    • Authors: Mattia Filippini, Piergiorgio Alotto, Vincenzo Cirimele, Maurizio Repetto, Carlo Ragusa, Luca Dimauro, Elvio Bonisoli
      First page: 1320
      Abstract: This paper proposes a procedure for computing magnetic losses in coaxial magnetic gears. These magnetic structures are made of permanent magnets and ferromagnetic poles in relative motion transferring torque between two shafts in a contactless way. The loss computation in magnetic materials is crucial to define the system performance. The flux distribution inside the iron parts is computed by means of the finite element method and a model of iron losses taking into account the rotational nature of the flux loci is applied. The procedure highlights where the major loss sources are present and gives the opportunity to evaluate some corrective measures to reduce their effects. Particular attention is devoted to the 2D modeling in presence of permanent magnets segmentation.
      Citation: Electronics
      PubDate: 2019-11-09
      DOI: 10.3390/electronics8111320
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1321: Fast Convolutional Neural Networks in Low
           Density FPGAs Using Zero-Skipping and Weight Pruning

    • Authors: Mário P. Véstias, Rui Policarpo Duarte, José T. de Sousa, Horácio C. Neto
      First page: 1321
      Abstract: Edge devices are becoming smarter with the integration of machine learning methods, such as deep learning, and are therefore used in many application domains where decisions have to be made without human intervention. Deep learning and, in particular, convolutional neural networks (CNN) are more efficient than previous algorithms for several computer vision applications such as security and surveillance, where image and video analysis are required. This better efficiency comes with a cost of high computation and memory requirements. Hence, running CNNs in embedded computing devices is a challenge for both algorithm and hardware designers. New processing devices, dedicated system architectures and optimization of the networks have been researched to deal with these computation requirements. In this paper, we improve the inference execution times of CNNs in low density FPGAs (Field-Programmable Gate Arrays) using fixed-point arithmetic, zero-skipping and weight pruning. The developed architecture supports the execution of large CNNs in FPGA devices with reduced on-chip memory and computing resources. With the proposed architecture, it is possible to infer an image in AlexNet in 2.9 ms in a ZYNQ7020 and 1.0 ms in a ZYNQ7045 with less than 1% accuracy degradation. These results improve previous state-of-the-art architectures for CNN inference.
      Citation: Electronics
      PubDate: 2019-11-09
      DOI: 10.3390/electronics8111321
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1322: USB Artifact Analysis Using Windows Event
           Viewer, Registry and File System Logs

    • Authors: Ashar Neyaz, Narasimha Shashidhar
      First page: 1322
      Abstract: A USB mass storage device yields a lot of artifacts when connected to a system. These artifacts are persistent in nature and are retained even after the system has been shut down and the information they contain may assist in carrying out forensic analysis on a suspect system. In this paper, we demonstrate how Windows Event Viewer can be used to find forensic artifacts in a suspect system for investigative purposes. We also discuss the potential that Windows registry holds to identify USB devices’ information that have been connected to the system, to corroborate our findings from Windows Event Viewer. Finally, we use the Windows 10 file system to extract log details that contain the setup information of a USB device that was connected to the system the very first time, and obtain the necessary identifiers and time stamp details.
      Citation: Electronics
      PubDate: 2019-11-09
      DOI: 10.3390/electronics8111322
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1323: SDR Based Indoor Beacon Localization
           Using 3D Probabilistic Multipath Exploitation and Deep Learning

    • Authors: Donald L. Hall, Ram M. Narayanan, David M. Jenkins
      First page: 1323
      Abstract: Wireless indoor positioning systems (IPS) are ever-growing as traditional global positioning systems (GPS) are ineffective due to non-line-of-sight (NLoS) signal propagation. In this paper, we present a novel approach to learning three-dimensional (3D) multipath channel characteristics in a probabilistic manner for providing high performance indoor localization of wireless beacons. The proposed system employs a single triad dipole vector sensor (TDVS) for polarization diversity, a deep learning model deemed the denoising autoencoder to extract unique fingerprints from 3D multipath channel information, and a probabilistic k-nearest-neighbor (PkNN) to exploit the 3D multipath characteristics. The proposed system is the first to exploit 3D multipath channel characteristics for indoor wireless beacon localization via vector sensing methodologies, a software defined radio (SDR) platform, and multipath channel estimation.
      Citation: Electronics
      PubDate: 2019-11-10
      DOI: 10.3390/electronics8111323
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1324: Li-ion Battery Modeling and State of
           Charge Estimation Method Including the Hysteresis Effect

    • Authors: Antonucci, Artale, Brunaccini, Caravello, Cataliotti, Cosentino, Cara, Ferraro, Guaiana, Panzavecchia, Sergi, Tinè
      First page: 1324
      Abstract: In this paper, a new approach to modeling the hysteresis phenomenon of the open circuit voltage (OCV) of lithium-ion batteries and estimating the battery state of charge (SoC) is presented. A characterization procedure is proposed to identify the battery model parameters, in particular, those related to the hysteresis phenomenon and the transition between charging and discharging conditions. A linearization method is used to obtain a suitable trade-off between the model accuracy and a low computational cost, in order to allow the implementation of SoC estimation on common hardware platforms. The proposed characterization procedure and the model effectiveness for SoC estimation are experimentally verified using a real grid-connected storage system. A mixed algorithm is adopted for SoC estimation, which takes into account both the traditional Coulomb counting method and the developed model. The experimental comparison with the traditional approach and the obtained results show the feasibility of the proposed approach for accurate SoC estimation, even in the presence of low-accuracy measurement transducers.
      Citation: Electronics
      PubDate: 2019-11-10
      DOI: 10.3390/electronics8111324
      Issue No: Vol. 8, No. 11 (2019)
       
  • Electronics, Vol. 8, Pages 1325: Fuel Cell Hybrid Model for Predicting
           Hydrogen Inflow through Energy Demand

    • Authors: José-Luis Casteleiro-Roca, Antonio Javier Barragán, Francisca Segura Manzano, José Luis Calvo-Rolle, José Manuel Andújar
      First page: 1325
      Abstract: Hydrogen-based energy storage and generation is an increasingly used technology, especially in renewable systems because they are non-polluting devices. Fuel cells are complex nonlinear systems, so a good model is required to establish efficient control strategies. This paper presents a hybrid model to predict the variation of H2 flow of a hydrogen fuel cell. This model combining clusters’ techniques to get multiple Artificial Neural Networks models whose results are merged by Polynomial Regression algorithms to obtain a more accurate estimate. The model proposed in this article use the power generated by the fuel cell, the hydrogen inlet flow, and the desired power variation, to predict the necessary variation of the hydrogen flow that allows the stack to reach the desired working point. The proposed algorithm has been tested on a real proton exchange membrane fuel cell, and the results show a great precision of the model, so that it can be very useful to improve the efficiency of the fuel cell system.
      Citation: Electronics
      PubDate: 2019-11-10
      DOI: 10.3390/electronics8111325
      Issue No: Vol. 8, No. 11 (2019)
       
 
 
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