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  Subjects -> ELECTRONICS (Total: 175 journals)
Showing 1 - 200 of 277 Journals sorted alphabetically
Acta Electronica Malaysia     Open Access  
Advances in Biosensors and Bioelectronics     Open Access   (Followers: 7)
Advances in Electrical and Electronic Engineering     Open Access   (Followers: 5)
Advances in Electronics     Open Access   (Followers: 76)
Advances in Magnetic and Optical Resonance     Full-text available via subscription   (Followers: 8)
Advances in Microelectronic Engineering     Open Access   (Followers: 13)
Advances in Power Electronics     Open Access   (Followers: 33)
Advancing Microelectronics     Hybrid Journal  
Aerospace and Electronic Systems, IEEE Transactions on     Hybrid Journal   (Followers: 304)
American Journal of Electrical and Electronic Engineering     Open Access   (Followers: 24)
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: 13)
Autonomous Mental Development, IEEE Transactions on     Hybrid Journal   (Followers: 8)
Bell Labs Technical Journal     Hybrid Journal   (Followers: 28)
Bioelectronics in Medicine     Hybrid Journal  
Biomedical Engineering, IEEE Reviews in     Full-text available via subscription   (Followers: 19)
Biomedical Engineering, IEEE Transactions on     Hybrid Journal   (Followers: 35)
Biomedical Instrumentation & Technology     Hybrid Journal   (Followers: 6)
Broadcasting, IEEE Transactions on     Hybrid Journal   (Followers: 12)
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: 44)
China Communications     Full-text available via subscription   (Followers: 8)
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: 253)
Edu Elektrika Journal     Open Access   (Followers: 1)
Electrica     Open Access  
Electronic Design     Partially Free   (Followers: 104)
Electronic Markets     Hybrid Journal   (Followers: 7)
Electronic Materials Letters     Hybrid Journal   (Followers: 4)
Electronics     Open Access   (Followers: 85)
Electronics and Communications in Japan     Hybrid Journal   (Followers: 10)
Electronics For You     Partially Free   (Followers: 91)
Electronics Letters     Hybrid Journal   (Followers: 26)
Elkha : Jurnal Teknik Elektro     Open Access  
Embedded Systems Letters, IEEE     Hybrid Journal   (Followers: 50)
Energy Harvesting and Systems     Hybrid Journal   (Followers: 4)
Energy Storage Materials     Full-text available via subscription   (Followers: 2)
EPJ Quantum Technology     Open Access  
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: 185)
Haptics, IEEE Transactions on     Hybrid Journal   (Followers: 4)
IACR Transactions on Symmetric Cryptology     Open Access  
IEEE Antennas and Propagation Magazine     Hybrid Journal   (Followers: 96)
IEEE Antennas and Wireless Propagation Letters     Hybrid Journal   (Followers: 77)
IEEE Journal of Emerging and Selected Topics in Power Electronics     Hybrid Journal   (Followers: 46)
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: 65)
IEEE Transactions on Antennas and Propagation     Full-text available via subscription   (Followers: 69)
IEEE Transactions on Automatic Control     Hybrid Journal   (Followers: 55)
IEEE Transactions on Circuits and Systems for Video Technology     Hybrid Journal   (Followers: 19)
IEEE Transactions on Consumer Electronics     Hybrid Journal   (Followers: 39)
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: 70)
IEEE Transactions on Signal and Information Processing over Networks     Full-text available via subscription   (Followers: 11)
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 Microwaves, Antennas & Propagation     Hybrid Journal   (Followers: 35)
IET Nanodielectrics     Open Access  
IET Power Electronics     Hybrid Journal   (Followers: 45)
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: 56)
Industry Applications, IEEE Transactions on     Hybrid Journal   (Followers: 23)
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: 12)
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: 10)
International Journal of Antennas and Propagation     Open Access   (Followers: 11)
International Journal of Applied Electronics in Physics & Robotics     Open Access   (Followers: 5)
International Journal of Computational Vision and Robotics     Hybrid Journal   (Followers: 6)
International Journal of Control     Hybrid Journal   (Followers: 12)
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: 2)
International Journal of High Speed Electronics and Systems     Hybrid Journal  
International Journal of Image, Graphics and Signal Processing     Open Access   (Followers: 14)
International Journal of Microwave and Wireless Technologies     Hybrid Journal   (Followers: 8)
International Journal of Nano Devices, Sensors and Systems     Open Access   (Followers: 12)
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: 24)
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: 3)
Journal of Advanced Dielectrics     Open Access   (Followers: 1)
Journal of Artificial Intelligence     Open Access   (Followers: 10)
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: 23)
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: 7)
Journal of Electromagnetic Waves and Applications     Hybrid Journal   (Followers: 8)
Journal of Electronic Design Technology     Full-text available via subscription   (Followers: 6)
Journal of Electronics (China)     Hybrid Journal   (Followers: 4)
Journal of Energy Storage     Full-text available via subscription   (Followers: 4)
Journal of Field Robotics     Hybrid Journal   (Followers: 2)
Journal of Guidance, Control, and Dynamics     Hybrid Journal   (Followers: 162)
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: 7)
Journal of Low Power Electronics and Applications     Open Access   (Followers: 9)
Journal of Microelectronics and Electronic Packaging     Hybrid Journal  
Journal of Microwave Power and Electromagnetic Energy     Hybrid Journal  
Journal of Microwaves, Optoelectronics and Electromagnetic Applications     Open Access   (Followers: 10)
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: 28)
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 Rekayasa Elektrika     Open Access  
Jurnal Teknik 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: 5)
Microelectronics and Solid State Electronics     Open Access   (Followers: 18)
Nanotechnology Magazine, IEEE     Full-text available via subscription   (Followers: 33)
Nanotechnology, Science and Applications     Open Access   (Followers: 6)
Nature Electronics     Hybrid Journal  
Networks: an International Journal     Hybrid Journal   (Followers: 6)
Open Journal of Antennas and Propagation     Open Access   (Followers: 8)
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: 1)
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)
Security and Communication Networks     Hybrid Journal   (Followers: 2)
Selected Topics in Applied Earth Observations and Remote Sensing, IEEE Journal of     Hybrid Journal   (Followers: 53)
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: 75)
Solid-State Circuits Magazine, IEEE     Hybrid Journal   (Followers: 13)
Solid-State Electronics     Hybrid Journal   (Followers: 9)
Superconductor Science and Technology     Hybrid Journal   (Followers: 2)
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: 8)
Universal Journal of Electrical and Electronic Engineering     Open Access   (Followers: 6)
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
Journal Prestige (SJR): 0.548
Citation Impact (citeScore): 3
Number of Followers: 85  

  This is an Open Access Journal Open Access journal
ISSN (Print) 2079-9292
Published by MDPI Homepage  [205 journals]
  • Electronics, Vol. 8, Pages 136: An Efficient Equalizing Method for
           Lithium-Ion Batteries Based on Coupled Inductor Balancing

    • Authors: Ali Farzan Moghaddam, Alex Van den Bossche
      First page: 136
      Abstract: This article developed a coupled inductor balancing method to overcome cell voltage variation among cells in series, for Lithium Ion (Li-ion) batteries in Electrical Vehicles (EV). For an "eight cells in series" example, the developed balance circuit has four inductors, one magnetic circuit with one winding per two cells, and one control switch per cell, as compared to the traditional inductor-based equalizer that needs N-1 inductors and magnetic circuits for N number of cells and more switches. Therefore, ultimately, a more efficient, cost-effective circuit and low bill of materials (BOM) will be built up. All switches are logic-level N-Channel metal-oxide-semiconductor field-effect transistors (MOSFETs) and they are controlled by a pair of complementary signals in a synchronous trigger pattern. In the proposed topology, less components and fast equalization are achieved compared to the conventional battery management system (BMS) technique for electrical vehicles based on the inductor balancing method. This scheme is suitable for fast equalization due to the inductor-based balancing method. The inductors are made with a well-chosen winding ratio and all are coupled with one magnetic core with an air gap. Theoretical derivation of the proposed circuit was well-presented, and numerical simulation relevant to the electrochemical storage devices was conducted to show the validity of the proposed balance circuit. A complete balance circuit was built to verify that the proposed circuit could resolve imbalance problems which existed inside battery modules.
      Citation: Electronics
      PubDate: 2019-01-29
      DOI: 10.3390/electronics8020136
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 137: Multi-Objective Optimization of Fog
           Computing Assisted Wireless Powered Networks: Joint Energy and Time

    • Authors: Yuan Liu, Ke Xiong, Yu Zhang, Li Zhou, Fuhong Lin, Tong Liu
      First page: 137
      Abstract: This paper studies the optimal design of the fog computing assisted wireless powered network, where an access point (AP) transmits information and charges an energy-limited sensor device with Radio Frequency (RF) energy transfer. The sensor device then uses the harvested energy to decode information and execute computing. Two candidate computing modes, i.e., local computing and fog computing modes, are considered. Two multi-objective optimization problems are formulated to minimize the required energy and time for the two modes, where the time assignments and the transmit power are jointly optimized. For the local computing mode, we obtain the closed-form expression of the optimal time assignment for energy harvesting by solving a convex optimization problem, and then analyze the effects of scaling factor between the minimal required energy and time on the optimal time assignment. For the fog computing mode, we derive closed-form and semi-closed-form expressions of the optimal transmit power and time assignment for offloading by adopting the Lagrangian dual method, the Karush–Kuhn–Tucker (KKT) conditions and Lambert W Function. Simulation results show that, when the sensor device has poor computing capacity or when it is far away from the AP, the fog computing mode is the better choice; otherwise, the local computing is preferred to achieve a better performance.
      Citation: Electronics
      PubDate: 2019-01-29
      DOI: 10.3390/electronics8020137
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 138: Outage and Throughput of WPCN-SWIPT
           Networks with Nonlinear EH Model in Nakagami-m Fading

    • Authors: Ruihong Jiang, Ke Xiong, Yu Zhang, Li Zhou, Tong Liu, Zhangdui Zhong
      First page: 138
      Abstract: This paper analyzes outage probability and reliable throughput performance of a multi-user wireless-powered communication network-simultaneous wireless information and power transfer (WPCN-SWIPT) network with the logistic function-based (LG) nonlinear energy-harvesting (EH) model in Nakagami-m fading. Power-splitting (PS) receiver architecture is considered. The closed-form expressions of the system outage probability and the system reliable throughput are derived, and then the corresponding asymptotic expressions are also provided to achieve simpler calculation in the high-transmit power scenarios. Simulation results demonstrate the correctness of our derived analytical results and show that the systems under the LG nonlinear and linear EH models have very different performance behaviors. Moreover, since the LG nonlinear EH model is closer to the features of practical EH circuit than the linear one, using the LG nonlinear EH model can avoid the false output results of the system performance evaluation.
      Citation: Electronics
      PubDate: 2019-01-29
      DOI: 10.3390/electronics8020138
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 139: Performance Analysis of a Modernized
           Z-Source Inverter for Robust Boost Control in Photovoltaic Power
           Conditioning Systems

    • Authors: Nafis Subhani, Ramani Kannan, Md Apel Mahmud, Mohd Fakhizan Romlie
      First page: 139
      Abstract: In this paper, the performance of a new Z-source inverter (ZSI)-based single-stage power conditioning system (PCS) is analyzed for a standalone photovoltaic (PV) power generation system. The proposed ZSI-based PCS includes two main parts: one is the input from PV units and the other is the ZSI. In this work, a new topology, termed the switched inductor-assisted strong boost ZSI (SL-SBZSI), is introduced for improving the performance of the PCS. The proposed topology shows high boosting capability during the voltage sag in PV units due to variations in solar irradiation and temperature. Another key advantage is the reduced capacitor voltage stress and semiconductor switch voltage stress of the inverter bridge, which ultimately minimizes the size and cost of the single-stage PCS. The proposed ZSI topology falls under the doubly grounded category of inverter by sharing the common ground between the input and output. This is an additional feature that can minimize the leakage current of PV units at the ac output end. The operational principles, detailed mathematical modeling, and characteristics of the proposed SL-SBZSI for a standalone photovoltaic (PV) power generation system is presented in this paper for analyzing performance. The simulation results, which are performed in MATLAB/Simulink, demonstrate the improved performance of the proposed SL-SBZSI for the standalone PV system. The performance of the proposed topology is also evaluated through an experimental validation on a laboratory-based PV system.
      Citation: Electronics
      PubDate: 2019-01-29
      DOI: 10.3390/electronics8020139
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 140: Multi-Sensor Optimization Scheduling for
           Target Tracking Based on PCRLB and a Novel Intercept Probability Factor

    • Authors: Gongguo Xu, Ce Pang, Xiusheng Duan, Ganlin Shan
      First page: 140
      Abstract: In order to improve the survivability of active sensors, the problem of low probability of intercept (LPI) for a multi-sensor network system is studied in this paper. Two kinds of operational requirements are taken into account, the first of which is to ensure the survivability of sensors and the second is to improve the tracking accuracy of targets as much as possible. Firstly, the sensor tracking model and the posterior Carmér-Rao lower bound (PCRLB) of the target are presented to evaluate the sensor tracking benefits in next time. Then, a novel intercept probability factor (IPF) is proposed for multi-sensor multi-target tracking scenarios. At the basis of PCRLB and IPF, a myopic multi-sensor scheduling model for target tracking is set up to control the intercepted probability of sensors and improve the target tracking accuracy. At last, a fast solution algorithm based on an improved particle swarm optimization (PSO) algorithm is given to obtain the optimal scheduling actions. Simulation of experimental results show that the proposed model can effectively control the intercepted risk of every sensor, which can also obtain better target tracking performance than existing multi-sensor scheduling methods.
      Citation: Electronics
      PubDate: 2019-01-29
      DOI: 10.3390/electronics8020140
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 141: Ring-Shaped Sensitive Element Design for
           Acceleration Measurements: Overcoming the Limitations of Angular-Shaped

    • Authors: Sergey Yu. Shevchenko, Maria A. Khivrich, Oleg A. Markelov
      First page: 141
      Abstract: A new modification of an acceleration measurement sensor based on an acoustic waves resonance principle is proposed. Common angular-shaped sensors exhibit stress concentrations at the angular points near the origin points of destruction under external stresses; these points are the “Achilles’ heel” of the entire design. To overcome the above limitation, we suggest an angular-free ring-shaped sensitive element design that is characterized by enhanced robustness against external stress. The analytical treatment is validated by computer simulation results performed using the COMSOL Multiphysics software package. For an appropriate model parameterization, an original experiment has been carried out to estimate the stress-strained robustness of two potential candidates for sensitive console materials. Moreover, characteristics of the proposed sensor design, such as sensitivity threshold and maximum stress, have been obtained from the simulation data. The above results indicate that the proposed concept offers a promising advancement in surface acoustic waves (SAW) based accelerometer devices, and could, therefore, be used for several practical applications in such areas as biomedical and sports wearable devices; vehicular design, including unmanned solutions; and industrial robotics, especially those where high-G forces are expected.
      Citation: Electronics
      PubDate: 2019-01-29
      DOI: 10.3390/electronics8020141
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 142: Towards Human Motion Tracking:
           Multi-Sensory IMU/TOA Fusion Method and Fundamental Limits

    • Authors: Cheng Xu, Jie He, Xiaotong Zhang, Xinghang Zhou, Shihong Duan
      First page: 142
      Abstract: Human motion tracking could be viewed as a multi-target tracking problem towards numerous body joints. Inertial-measurement-unit-based human motion tracking technique stands out and has been widely used in body are network applications. However, it has been facing the tough problem of accumulative errors and drift. In this paper, we propose a multi-sensor hybrid method to solve this problem. Firstly, an inertial-measurement-unit and time-of-arrival fusion-based method is proposed to compensate the drift and accumulative errors caused by inertial sensors. Secondly, Cramér–Rao lower bound is derived in detail with consideration of both spatial and temporal related factors. Simulation results show that the proposed method in this paper has both spatial and temporal advantages, compared with traditional sole inertial or time-of-arrival-based tracking methods. Furthermore, proposed method is verified in 3D practical application scenarios. Compared with state-of-the-art algorithms, proposed fusion method shows better consistency and higher tracking accuracy, especially when moving direction changes. The proposed fusion method and comprehensive fundamental limits analysis conducted in this paper can provide a theoretical basis for further system design and algorithm analysis. Without the requirements of external anchors, the proposed method has good stability and high tracking accuracy, thus it is more suitable for wearable motion tracking applications.
      Citation: Electronics
      PubDate: 2019-01-29
      DOI: 10.3390/electronics8020142
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 143: An Accelerator Architecture of
           Changeable-Dimension Matrix Computing Method for SVM

    • Authors: Ruidong Wu, Bing Liu, Ping Fu, Junbao Li, Shou Feng
      First page: 143
      Abstract: Matrix multiplication is a critical time-consuming processing step in many machine learning applications. Due to the diversity of practical applications, the matrix dimensions are generally not fixed. However, most matrix calculation methods, based on field programmable gate array (FPGA) currently use fixed matrix dimensions, which limit the flexibility of machine learning algorithms in a FPGA. The bottleneck lies in the limited FPGA resources. Therefore, this paper proposes an accelerator architecture for matrix computing method with changeable dimensions. Multi-matrix synchronous calculation concept allows matrix data to be processed continuously, which improves the parallel computing characteristics of FPGA and optimizes the computational efficiency. This paper tests matrix multiplication using support vector machine (SVM) algorithm to verify the performance of proposed architecture on the ZYNQ platform. The experimental results show that, compared to the software processing method, the proposed architecture increases the performance by 21.18 times with 9947 dimensions. The dimension is changeable with a maximum value of 2,097,151, without changing hardware design. This method is also applicable to matrix multiplication processing with other machine learning algorithms.
      Citation: Electronics
      PubDate: 2019-01-30
      DOI: 10.3390/electronics8020143
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 144: A Simple Closed-Loop Active Gate Voltage
           Driver for Controlling diC/dt and dvCE/dt in IGBTs

    • Authors: Hamidreza Ghorbani, Vicent Sala, Alejandro Paredes Camacho, Jose Luis Romeral Martinez
      First page: 144
      Abstract: The increase of the switching speed in power semiconductors leads to converters with better efficiency and high power density. On the other hand, fast switching generates some consequences like overshoots and higher switching transient, which provoke electromagnetic interference (EMI). This paper proposes a new closed-loop gate driver to improve switching trajectory in insulated gate bipolar transistors (IGBTs) at the hard switching condition. The proposed closed-loop gate driver is based on an active gate voltage control method, which deals with emitter voltage (VEe) for controlling diC/dt and gets feedback from the output voltage (vCE) in order to control dvCE/dt. The sampled voltage signals modify the profile of the applied gate voltage (vgg). As a result, the desired gate driver (GD) improves the switching transients with minimum switching loss. The operation principle and implementation of the controller in the GD are thoroughly described. It can be observed that the new GD controls both dvCE/dt and diC/dt accurately independent of the variable parameters. The new control method is verified by experimental results. As a current issue, the known trade-off between switching losses and EMI is improved by this simple and effective control method.
      Citation: Electronics
      PubDate: 2019-01-30
      DOI: 10.3390/electronics8020144
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 145: Enhancing PUF Based Challenge–Response
           Sets by Exploiting Various Background Noise Configurations

    • Authors: Honorio Martin, Pedro Peris-Lopez, Giorgio Natale, Mottaqiallah Taouil, Said Hamdioui
      First page: 145
      Abstract: Physically Unclonable Functions (PUFs) are a cryptographic primitive that exploit the unique physical characteristics of Integrated Circuits (ICs). A PUF can be modeled as a black-box challenge–response system. The number and size of challenge–response pairs (CRPs) supported by a PUF determine and condition its strength. Ring Oscillators (RO)-based PUF, which are one of the most implemented on FPGA, suffer from a low number and size of CRPs. In this work, we propose an innovative mechanism to expand the size of the CRPs in a RO-PUF by using multiple bits of the two ROs under comparison. To satisfy the reliability and enhance the quality of these responses, we either switch the remaining ROs that are not used for the comparison off or use them as a background noise. We validated our proposal using FPGA measurements. The results show that, with the same number of Ring Oscillators, the CRP size can be doubled with a minimum area overhead.
      Citation: Electronics
      PubDate: 2019-01-30
      DOI: 10.3390/electronics8020145
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 146: Active Eavesdropping Detection Based on
           Large-Dimensional Random Matrix Theory for Massive MIMO-Enabled IoT

    • Authors: Li Xu, Jiaqi Chen, Ming Liu, Xiaoyi Wang
      First page: 146
      Abstract: The increasing Internet-of-Things (IoT) applications will take a significant share of the services of the fifth generation mobile network (5G). However, IoT devices are vulnerable to security threats due to the limitation of their simple hardware and communication protocol. Massive multiple-input multiple-output (massive MIMO) is recognized as a promising technique to support massive connections of IoT devices, but it faces potential physical layer breaches. An active eavesdropper can compromises the communication security of massive MIMO systems by purposely contaminating the uplink pilots. According to the random matrix theory (RMT), the eigenvalue distribution of a large dimensional matrix composed of data samples converges to the limit spectrum distribution that can be characterized by matrix dimensions. With the assistance of RMT, we propose an active eavesdropping detection method in this paper. The theoretical limit spectrum distribution is exploited to determine the distribution range of the eigenvalues of a legitimate user signal. In addition the noise components are removed using the Marčenko–Pastur law of RMT. Hypothesis testing is then carried out to determine whether the spread range of eigenvalues is “normal” or not. Simulation results show that, compared with the classical Minimum Description Length (MDL)-based detection algorithm, the proposed method significantly improves active eavesdropping detection performance.
      Citation: Electronics
      PubDate: 2019-01-31
      DOI: 10.3390/electronics8020146
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 147: Demand Forecasting DBA Algorithm for
           Reducing Packet Delay with Efficient Bandwidth Allocation in XG-PON

    • Authors: Kamran Ali Memon, Khalid H. Mohammadani, Noor ul Ain, Arshad Shaikh, Sibghat Ullah, Qi Zhang, Bhagwan Das, Rahat Ullah, Feng Tian, Xiangjun Xin
      First page: 147
      Abstract: In a typical 10G-Passive Optical Network (XG-PON), the propagation delay between the Optical Network Unit (ONU) and Optical Line Terminal (OLT) is about 0.3 ms. With a frame size of 125 μs, this amounts to three frames of data in the upstream and three frames of data in the downstream. Assuming no processing delays, the grants for any bandwidth requests reach the ONU after six frames in this request-grant cycle. Often, during this six-frame delay, the queue situation is changed drastically, as much, more data would arrive in the queue. As a result, the queued data that is delayed loses its significance due to its real-time nature. Unfortunately, almost all dynamic bandwidth allocation (DBA) algorithms follow this request-grant cycle and hence lacking in their performance. This paper introduces a novel approach for bandwidth allocation, called Demand Forecasting DBA (DF-DBA), which predicts ONU’s future demands by statistical modelling of the demand patterns and tends to fulfil the predicted demands just in time, which results in reduced delay. Simulation results indicate that the proposed technique out-performs previous DBAs, such as GigaPON access network (GIANT) and round robin (RR) employing the request-grant cycle in terms of Throughput and Packet delivery ratio (PDR). Circular buffers are introduced in statistical predictions, which produce the least delay for this novel DF-DBA. This paper, hence, opens up a new horizon of research in which researchers may come up with better statistical models to brew better and better results for Passive optical networks.
      Citation: Electronics
      PubDate: 2019-01-31
      DOI: 10.3390/electronics8020147
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 148: Trajectory Protection Schemes Based on a
           Gravity Mobility Model in IoT

    • Authors: Qiong Wu, Hanxu Liu, Cui Zhang, Qiang Fan, Zhengquan Li, Kan Wang
      First page: 148
      Abstract: With the proliferation of the Internet-of-Things (IoT), the users’ trajectory data containing privacy information in the IoT systems are easily exposed to the adversaries in continuous location-based services (LBSs) and trajectory publication. Existing trajectory protection schemes generate dummy trajectories without considering the user mobility pattern accurately. This would cause that the adversaries can easily exclude the dummy trajectories according to the obtained geographic feature information. In this paper, the continuous location entropy and the trajectory entropy are defined based on the gravity mobility model to measure the level of trajectory protection. Then, two trajectory protection schemes are proposed based on the defined entropy metrics to protect the trajectory data in continuous LBSs and trajectory publication, respectively. Experimental results demonstrate that the proposed schemes have a higher level than the enhanced dummy-location selection (enhance-DLS) scheme and the random scheme.
      Citation: Electronics
      PubDate: 2019-01-31
      DOI: 10.3390/electronics8020148
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 149: Economic Analysis of Grid-Connected PV
           System Regulations: A Hungarian Case Study

    • Authors: Henrik Zsiborács, Nóra Hegedűsné Baranyai, Szilvia Csányi, András Vincze, Gábor Pintér
      First page: 149
      Abstract: The energy demand of mankind is constantly growing, thus the utilization of various renewable energy sources, which also reduces negative environmental effects, is becoming more and more important. Because of the achievement of climate protection targets, photovoltaic (PV) energy has an increasing role in the global energy mix. This paper presents the technical and economic aspects of different photovoltaic system configurations designed to suit the Hungarian renewable energy regulations. In this study, five alternative PV configurations were examined for systems with a capacity from 50 kW to 500 kW, related to low- and medium-voltage installations. This article also introduces and explains the Hungarian economic PV and Feed-in-Tariff (FiT) regulations, where three different investment alternatives are analyzed with the help of economic indicators. This study could help stakeholders in the market (e.g., the Hungarian industry sector and local governments) understand the possible directions of technical and economic PV development. According to the results, the payback periods in all the studied economic-technical cases were below 10 years. The experimental results show that each investment option may be a good decision from an economic and technical point of view under the Hungarian regulations in force in 2019.
      Citation: Electronics
      PubDate: 2019-01-31
      DOI: 10.3390/electronics8020149
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 150: CMOS Interfaces for Internet-of-Wearables
           Electrochemical Sensors: Trends and Challenges

    • Authors: Michele Dei, Joan Aymerich, Massimo Piotto, Paolo Bruschi, Francisco Javier del Campo, Francesc Serra-Graells
      First page: 150
      Abstract: Smart wearables, among immediate future IoT devices, are creating a huge and fast growing market that will encompass all of the next decade by merging the user with the Cloud in a easy and natural way. Biological fluids, such as sweat, tears, saliva and urine offer the possibility to access molecular-level dynamics of the body in a non-invasive way and in real time, disclosing a wide range of applications: from sports tracking to military enhancement, from healthcare to safety at work, from body hacking to augmented social interactions. The term Internet of Wearables (IoW) is coined here to describe IoT devices composed by flexible smart transducers conformed around the human body and able to communicate wirelessly. In addition the biochemical transducer, an IoW-ready sensor must include a paired electronic interface, which should implement specific stimulation/acquisition cycles while being extremely compact and drain power in the microwatts range. Development of an effective readout interface is a key element for the success of an IoW device and application. This review focuses on the latest efforts in the field of Complementary Metal–Oxide–Semiconductor (CMOS) interfaces for electrochemical sensors, and analyses them under the light of the challenges of the IoW: cost, portability, integrability and connectivity.
      Citation: Electronics
      PubDate: 2019-01-31
      DOI: 10.3390/electronics8020150
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 151: Nano-Particle VO2 Insulator-Metal
           Transition Field-Effect Switch with 42 mV/decade Sub-Threshold Slope

    • Authors: Massood Tabib-Azar, Rugved Likhite
      First page: 151
      Abstract: The possibility of controlling the insulator-to-metal transition (IMT) in nano-particle VO2 (NP-VO2) using the electric field effect in a metal-oxide-VO2 field-effect transistor (MOVFET) at room temperature was investigated for the first time. The IMT induced by current in NP-VO2 is a function of nano-particle size and was studied first using the conducting atomic force microscope (cAFM) current-voltage (I-V) measurements. NP-VO2 switching threshold voltage (VT), leakage current (Ileakage), and the sub-threshold slope of their conductivity (Sc) were all determined. The cAFM data had a large scatter. However, VT increased as a function of particle height (h) approximately as VT(V) = 0.034 h, while Ileakage decreased as a function of h approximately as Ileakage (A) = 3.4 × 10−8e−h/9.1. Thus, an asymptotic leakage current of 34 nA at zero particle size and a tunneling (carrier) decay constant of ~9.1 nm were determined. Sc increased as a function of h approximately as Sc (mV/decade) = 2.1 × 10−3eh/6 and was around 0.6 mV/decade at h~34 nm. MOVFETs composed of Pt drain, source and gate electrodes, HfO2 gate oxide, and NP-VO2 channels were then fabricated and showed gate voltage dependent drain-source switching voltage and current (IDS). The subthreshold slope (St) of drain-source current (IDS) varied from 42 mV/decade at VG = −5 V to 54 mV/decade at VG = +5 V.
      Citation: Electronics
      PubDate: 2019-02-01
      DOI: 10.3390/electronics8020151
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 152: Multi-Sensor Satellite Data Processing for
           Marine Traffic Understanding

    • Authors: Marco Reggiannini, Luigi Bedini
      First page: 152
      Abstract: The work described in this document concerns the estimation of the kinematics of a navigating vessel. This task can be accomplished through the exploitation of satellite-borne systems for Earth observation. Indeed, Synthetic Aperture Radar (SAR) and optical sensors installed aboard satellites (European Space Agency Sentinel, ImageSat International Earth Remote Observation System, Italian Space Agency Constellation of Small Satellites for Mediterranean basin Observation) return multi-resolution maps providing information about the marine surface. A moving ship represented through satellite imaging results in a bright oblong object, with a peculiar wake pattern generated by the ship’s passage throughout the water. By employing specifically tailored computer vision methods, these vessel features can be identified and individually analyzed for what concerns geometrical and radiometric properties, backscatterers spatial distribution and the spectral content of the wake components. This paper proposes a method for the automatic detection of the vessel’s motion-related features and their exploitation to provide an estimation of the vessel velocity vector. In particular, the ship’s related wake pattern is considered as a crucial target of interest for the purposes mentioned. The corresponding wake detection module has been implemented adopting a novel approach, i.e., by introducing a specifically tailored gradient estimator in the early processing stages. This results in the enhancement of the turbulent wake detection performance. The resulting overall procedure may also be included in marine surveillance systems in charge of detecting illegal maritime traffic, combating unauthorized fishing, irregular migration and related smuggling activities.
      Citation: Electronics
      PubDate: 2019-02-01
      DOI: 10.3390/electronics8020152
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 153: Multiresolution Virtual Experiments for
           Microwave Imaging of Complex Scenarios

    • Authors: Martina T. Bevacqua, Roberta Palmeri, Rosa Scapaticci
      First page: 153
      Abstract: In this paper, a multiresolution approach for the quantitative microwave imaging of complex scenarios is introduced. The proposed strategy takes advantage of the combined use of a recently introduced iterative method known as distorted iterated virtual experiments (DIVE), based on the paradigm of “virtual experiments”, and a wavelet-based projection scheme. This strategy allows the unknown profiles to be represented at different resolution scales and, as such, it is particularly suitable for the imaging of highly heterogeneous targets. Moreover, the developed algorithm blends together the intrinsic multiresolution feature of the wavelet projection with the one gained by means of a frequency hopping technique. The method was tested against realistic heterogeneous scenarios of practical interest, such as breast and tree trunk phantoms, which are of interest in non-invasive medical diagnostics and the health monitoring of standing trees.
      Citation: Electronics
      PubDate: 2019-02-01
      DOI: 10.3390/electronics8020153
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 154: An Efficient LMS Platform and Its Test Bed

    • Authors: Sooyoung Jung, Jun-Ho Huh
      First page: 154
      Abstract: In order to develop an e-learning system as a method of education that frees both the teacher and learner from the constraints of time and space, it is necessary to develop software and to build the network equipment required to operate the software. The most basic system consists of a web server, a database server, and a video server. However, these elements are vulnerable to both internal and external threats. As for the web, database, and video servers, it is possible to respond to such threats by operating more than two devices, but this inevitably increases the cost of building the equipment. Therefore, this study proposed the use of a cloud service, such as AWS (Amazon Web Service), in order to save on the costs of purchasing, installing, and operating the servers, as well as a service designed to strengthen security by employees or trainees who understand the internal situation of the training institute. In other words, this study proposed the development of an efficient Learning Management System (LMS) platform and proved its efficiency using a test bed over a period of three years. The major contribution of this study is that the design of the proposed LMS has been improved to provide a more efficient performance than the existing LMSs by surmounting the traffic overload problem often found in video services. This is achieved by utilizing a lesser number of servers and maintaining the balance of the loads. Also, the interface used for the system can be adaptable to most of the web servers as they support Java, Android, and HTML-based systems. As a cloud-based LMS, this system has been tested for its efficiency and effectiveness for a period of three years during which the results have been satisfactory.
      Citation: Electronics
      PubDate: 2019-02-01
      DOI: 10.3390/electronics8020154
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 155: DC-Link Capacitor Voltage Imbalance
           Compensation Method Based Injecting Harmonic Voltage for Cascaded
           Multi-Module Neutral Point Clamped Inverter

    • Authors: Kyoung-Pil Kang, Younghoon Cho, Ho-Sung Kim, Ju-won Baek
      First page: 155
      Abstract: In a three-level (NPC) converter, the voltage imbalance problem in the DC-link capacitors is major issue. This paper proposes the DC-link capacitor voltage imbalance compensation method, where a common offset voltage is injected for a multi-module NPC inverter. The offset voltage consists of a harmonic voltage and a voltage difference between the upper and lower capacitors. The proposed method does not require any hardware modification, so that it is easily implemented. In order to show the effectiveness of the proposed balancing method, theoretical analysis is provided to balance the voltages, and both the simulations and the experiments were carried out to show that the voltage difference of the DC-link was decreased by the proposed method.
      Citation: Electronics
      PubDate: 2019-02-01
      DOI: 10.3390/electronics8020155
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 156: Mitigating the Load Frequency Fluctuations
           of Interconnected Power Systems Using Model Predictive Controller

    • Authors: Muhammad Gulzar, Syed Rizvi, Muhammad Javed, Daud Sibtain, Rubab Salah ud Din
      First page: 156
      Abstract: The penetration of renewable energy sources into the conventional power systems are evolving day by day. Therefore, in this paper, a photovoltaic (PV) connected thermal system is discussed and analyzed by keeping PV to operate at maximum power point (MPP). The main problem in the interconnection of these systems is load frequency fluctuations due to different load changing conditions. The model predictive controller (MPC) has the ability to predict the target value at real-time with fast convergence. Therefore, MPC is proposed to negate this problem by giving minimum oscillation. The comparison analysis is carried out with other conventional controllers, including genetic algorithm-based PI, firefly algorithm-based PI and PI controller. Simulation results clearly exhibit the outclass performance of MPC over all other controllers.
      Citation: Electronics
      PubDate: 2019-02-01
      DOI: 10.3390/electronics8020156
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 157: A New Type of AODF Based on an Imitation
           of the Weft Insertion of a Rapier Loom

    • Authors: Shimin Wei, Zheng Yang, Lei Guo, Yuan Song
      First page: 157
      Abstract: The main distribution frame (MDF) is an important component between the user and the operator that supplies a telecommunication service and is the only layer in the seven-layer communication architecture that is not fully automated. In this paper, a cross-connect method for simulating the rapier picking of a rapier loom (shuttleless loom) is proposed to imitate the shedding and the picking action to achieve quick switching. Using the designed “shedding device” and “picking device”, a model prototype of the automatic optical distribution frame (AODF) was constructed and tested for verification.
      Citation: Electronics
      PubDate: 2019-02-01
      DOI: 10.3390/electronics8020157
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 158: Compact UWB Band-Notched Antenna with
           Integrated Bluetooth for Personal Wireless Communication and UWB

    • Authors: MuhibUr Rahman, Mahdi NagshvarianJahromi, Seyed Sajad Mirjavadi, Abdel Magid Hamouda
      First page: 158
      Abstract: A compact band-notched UWB (Ultra-Wide Band) antenna with integrated Bluetooth is developed for personal wireless communication and UWB applications. The antenna operates at the UWB frequency band (3.1–10.6 GHz) as well as Bluetooth (2.4–2.484 GHz), with band-notch characteristics at the Wireless Local Area Network (WLAN) frequency band (5–6 GHz). A new technique of integrating Bluetooth within a UWB band-notched antenna is developed and analyzed. The UWB frequency band is realized by utilizing a conventional cylindrical radiating patch and a modified partial ground plane. The Bluetooth band is integrated using a miniaturized resonator with the addition of capacitors. Further, to mitigate the interference of the WLAN frequency band within the UWB spectrum, a conventional slot resonator is integrated within the radiator to achieve the task. The antenna is designed and fabricated, and its response in each case is provided. Moreover, the antenna exhibits a good radiation pattern with a stable gain in the passband. The present antenna is also compared to state-of-the-art structures proposed in the literature. The miniaturized dimensions (30 × 31 mm2) of the antenna make it an excellent candidate for UWB and personal wireless communication applications.
      Citation: Electronics
      PubDate: 2019-02-01
      DOI: 10.3390/electronics8020158
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 159: A Free Navigation of an AGV to a
           Non-Static Target with Obstacle Avoidance

    • Authors: Daniel Teso-Fz-Betoño, Ekaitz Zulueta, Unai Fernandez-Gamiz, Iñigo Aramendia, Irantzu Uriarte
      First page: 159
      Abstract: The industry is changing in order to improve the economy sector. This is the reason why technology is improving and developing new devices. The autonomous guided vehicle with free navigation is a new machine, which uses different techniques to move such as mapping, localization, path planning, and path following. In this paper, a path following is proposed. The path following is called moving to a point, which uses the proportional distance between the target and the autonomous guided vehicles (AGV) to calculate the velocity and direction. If some obstacles appear in the trajectory, however, the vehicle stops. Instead of stopping the machine, by using moving to a point logic, an obstacle avoidance function will be implemented. In this implementation, different parameters can be configured, such as: security distance, which determinates when the obstacle avoidance must correct the pose; and proportional values, which modify the velocity and steering commands. It is also compared to a dynamic window approach (DWA) obstacle avoidance solution. Additionally, the AGV navigates to a non-static target with a path following algorithm.
      Citation: Electronics
      PubDate: 2019-02-01
      DOI: 10.3390/electronics8020159
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 160: Optimization Algorithm for Multiple Phases
           Sectionalized Modulation Jamming Based on Particle Swarm Optimization

    • Authors: Jiawei Jiang, Yanhong Wu, Hongyan Wang, Yakun Lv, Lei Qiu, Daobin Yu
      First page: 160
      Abstract: Due to the difficulty in deducing the corresponding relationship between results and parameter settings of multiple phases sectionalized modulation (MPSM) jamming, a problem occurs when obtaining the optimal local suppression jamming effect, which limits the practical application of MPSM jamming. The traditional method struggles to meet the requirements by setting fixed parameters or random parameters. Therefore, an optimization algorithm for MPSM jamming based on particle swarm optimization (PSO) is proposed in this study to produce the optimal local suppression jamming effect and determine its corresponding parameter settings. First, we analyzed the relationship between the degree of mismatch and local suppression jamming effect. Then, we set appropriate fitness function and fitness value. Finally, we used PSO to calculate parameter settings of a section situation and phase situation, which minimizes the fitness function and fitness value. The optimization algorithm avoids the tremendous computation of traversing all parameter settings, is stable, the results are repeatable, and the algorithm provides the optimal local suppression jamming effect under different conditions. The simulation experiments demonstrate the feasibility and effectiveness of the optimization algorithm.
      Citation: Electronics
      PubDate: 2019-02-01
      DOI: 10.3390/electronics8020160
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 161: Generalized Cascaded Symmetric and Level
           Doubling Multilevel Converter Topology with Reduced THD for Photovoltaic

    • Authors: Karthikeyan D, Vijayakumar K, Jagabar Sathik M
      First page: 161
      Abstract: In this paper, two different converter topologies for a basic new switched capacitor diode converter with a reduced number of power electronics components, suitable for grid connected photovoltaic applications were proposed. The two different structures of switched diode multilevel converter proposed were: (i) cascaded switched diode and (ii) cascaded switched diode with doubling circuit. The switched-diode multilevel converter was compared with other recent converters. In addition, a new dc offset nearest level modulation technique was proposed. This proposed dc offset technique offers low voltage total harmonic distortion (THD) and high RMS output voltage. The proposed modulation technique was compared with conventional nearest level modulation (NLM) and modified NLM control techniques. The performance of the proposed dc offset modulation technique was implemented using a FPGA Spartan 3E controller and tested with a novel switched capacitor-diode multilevel converter. However, to prove the authenticity of the switched-diode multilevel converter and modulation technique, a laboratory-based prototype model for 7-level and 13-level converters was developed.
      Citation: Electronics
      PubDate: 2019-02-01
      DOI: 10.3390/electronics8020161
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 162: Current State of Multicast Routing
           Protocols for Disruption Tolerant Networks: Survey and Open Issues

    • Authors: Khang-Siang Wong, Tat-Chee Wan
      First page: 162
      Abstract: The deployment of Internet of Things (IoT) applications in remote areas, such as environmental sensing areas, requires Disruption Tolerant Networking (DTN) support due to the lack of continuous network connectivity. IoT devices in DTN generate and store data until a network link is available for data transmission. Data mules or ferries are scheduled to travel among intermittent networks to collect data and disseminate configuration updates from control centers to all participating nodes in a reliable manner. The incorporation of efficient, reliable multicast algorithms into DTN helps to overcome the current limitations in updating large numbers of nodes in remote areas with identical configurations. In this paper, the current state of multicast routing protocols in DTN is outlined according to their design aspects. Open issues are also discussed to provide impetus for further research into the Reliable Multicast DTN (RMDTN) protocol.
      Citation: Electronics
      PubDate: 2019-02-01
      DOI: 10.3390/electronics8020162
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 163: Application of Artificial Neural Network
           for Image Noise Level Estimation in the SVD domain

    • Authors: Emir Turajlic, Alen Begović, Namir Škaljo
      First page: 163
      Abstract: The blind additive white Gaussian noise level estimation is an important and a challenging area of digital image processing with numerous applications including image denoising and image segmentation. In this paper, a novel block-based noise level estimation algorithm is proposed. The algorithm relies on the artificial neural network to perform a complex image patch analysis in the singular value decomposition (SVD) domain and to evaluate noise level estimates. The algorithm exhibits the capacity to adjust the effective singular value tail length with respect to the observed noise levels. The results of comparative analysis show that the proposed ANN-based algorithm outperforms the alternative single stage block-based noise level estimating algorithm in the SVD domain in terms of mean square error (MSE) and average error for all considered choices of block size. The most significant improvements in MSE levels are obtained at low noise levels. For some test images, such as “Car” and “Girlface”, at σ = 1 , these improvements can be as high as 99% and 98.5%, respectively. In addition, the proposed algorithm eliminates the error-prone manual parameter fine-tuning and automates the entire noise level estimation process.
      Citation: Electronics
      PubDate: 2019-02-01
      DOI: 10.3390/electronics8020163
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 164: Automatic Emotion-Based Music
           Classification for Supporting Intelligent IoT Applications

    • Authors: Seo, Huh
      First page: 164
      Abstract: With the arrival of the fourth industrial revolution, new technologies that integrate emotional intelligence into existing IoT applications are being studied. Of these technologies, emotional analysis research for providing various music services has received increasing attention in recent years. In this paper, we propose an emotion-based automatic music classification method to classify music with high accuracy according to the emotional range of people. In particular, when the new (unlearned) songs are added to a music-related IoT application, it is necessary to build mechanisms to classify them automatically based on the emotion of humans. This point is one of the practical issues for developing the applications. A survey for collecting emotional data is conducted based on the emotional model. In addition, music features are derived by discussing with the working group in a small and medium-sized enterprise. Emotion classification is carried out using multiple regression analysis and support vector machine. The experimental results show that the proposed method identifies most of induced emotions felt by music listeners and accordingly classifies music successfully. In addition, comparative analysis is performed with different classification algorithms, such as random forest, deep neural network and K-nearest neighbor, as well as support vector machine.
      Citation: Electronics
      PubDate: 2019-02-01
      DOI: 10.3390/electronics8020164
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 165: Stochastic Gradient Matching Pursuit
           Algorithm Based on Sparse Estimation

    • Authors: Liquan Zhao, Yunfeng Hu, Yulong Liu
      First page: 165
      Abstract: The stochastic gradient matching pursuit algorithm requires the sparsity of the signal as prior information. However, this prior information is unknown in practical applications, which restricts the practical applications of the algorithm to some extent. An improved method was proposed to overcome this problem. First, a pre-evaluation strategy was used to evaluate the sparsity of the signal and the estimated sparsity was used as the initial sparsity. Second, if the number of columns of the candidate atomic matrix was smaller than that of the rows, the least square solution of the signal was calculated, otherwise, the least square solution of the signal was set as zero. Finally, if the current residual was greater than the previous residual, the estimated sparsity was adjusted by the fixed step-size and stage index, otherwise we did not need to adjust the estimated sparsity. The simulation results showed that the proposed method was better than other methods in terms of the aspect of reconstruction percentage in the larger sparsity environment.
      Citation: Electronics
      PubDate: 2019-02-01
      DOI: 10.3390/electronics8020165
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 166: SSCFM: Separate Signature-Based Control
           Flow Error Monitoring for Multi-Threaded and Multi-Core Environments

    • Authors: Kiho Choi, Daejin Park, Jeonghun Cho
      First page: 166
      Abstract: Soft error is a key challenge in computer systems. Without soft error mitigation, control flow error (CFE) can lead to system crash. Signature-based CFE monitoring scheme is a representative technique for detecting CFEs during runtime. However, most of the signature-based CFE monitoring schemes proposed thus far are based on a single thread. Currently, the widely used multi-threaded and multi-core environments have greatly improved the performance of the computing system, but, if the these schemes are applied in these environments, performance improvement is difficult to achieve, or rather performance degradation may occur. In this paper, we propose a separate signature-based CFE monitoring (SSCFM) scheme that separates the signature update and the signature verification on the thread level. The signature update is combined with application thread and signature verification and executed on separate monitor threads, so that we can expect performance improvements in multi-threaded or multi-core environments. Furthermore, the SSCFM scheme can fully cover inter-procedural CFE not covered by many signature-based CFE monitoring schemes by using inter-procedural control flow analysis. With the proposed SSCFM scheme, the execution time overhead is reduced by approximately 26.67% on average from the SEDSR scheme, and the average CFE detection rate with SSCFM is approximately 93.69%. In addition, this paper also introduces the LLVM compiler-based SSCFM generator that makes it easy to apply the SSCFM scheme to software applications.
      Citation: Electronics
      PubDate: 2019-02-01
      DOI: 10.3390/electronics8020166
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 167: Multi-Points Cooperative Relay in NOMA
           System with N-1 DF Relaying Nodes in HD/FD Mode for N User Equipments with
           Energy Harvesting

    • Authors: Thanh-Nam Tran, Miroslav Voznak
      First page: 167
      Abstract: Non-Orthogonal Multiple Access (NOMA) is the key technology promised to be applied in next-generation networks in the near future. In this study, we propose a multi-points cooperative relay (MPCR) NOMA model instead of just using a relay as in previous studies. Based on the channel state information (CSI), the base station (BS) selects a closest user equipment (UE) and sends a superposed signal to this UE as a first relay node. We have assumed that there are N UEs in the network and the N-th UE, which is farthest from BS, has the poorest quality signal transmitted from the BS compared the other UEs. The N-th UE received a forwarded signal from N - 1 relaying nodes that are the UEs with better signal quality. At the i-th relaying node, it detects its own symbol by using successive interference cancellation (SIC) and will forward the superimposed signal to the next closest user, namely the ( i + 1 ) -th UE, and include an excess power which will use for energy harvesting (EH) intention at the next UE. By these, the farthest UE in network can be significantly improved. In addition, closed-form expressions of outage probability for users over both the Rayleigh and Nakagami-m fading channels are also presented. Analysis and simulation results performed by Matlab software, which are presented accurately and clearly, show that the effectiveness of our proposed model and this model will be consistent with the multi-access wireless network in the future.
      Citation: Electronics
      PubDate: 2019-02-01
      DOI: 10.3390/electronics8020167
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 168: Automatic Spray Trajectory Optimization on
           Bézier Surface

    • Authors: Wei Chen, Junjie Liu, Yang Tang, Huilin Ge
      First page: 168
      Abstract: The trajectory optimization of automatic spraying robot is still a challenging problem, which is very important in the whole spraying work. Spray trajectory optimization consists of two parts: spray space path and end-effector moving speed. A large number of spraying experiments have proved that it is very important to find the best initial trajectory of spraying. This paper presents an automatic spray trajectory optimization that is based on the Bézier surface. Spray the workpiece for Bezier triangular surface modeling and find the best initial trajectory of the spraying robot, establish the appropriate spraying model, plan the appropriate space path, and finally plan the trajectory optimization along the specified painting path. The validity and practicability of the method presented in this paper are proved by an example. This method can also be extended to other applications.
      Citation: Electronics
      PubDate: 2019-02-01
      DOI: 10.3390/electronics8020168
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 169: A Review of Electric Impedance Matching
           Techniques for Piezoelectric Sensors, Actuators and Transducers

    • Authors: Rathod
      First page: 169
      Abstract: Any electric transmission lines involving the transfer of power or electric signal requires the matching of electric parameters with the driver, source, cable, or the receiver electronics. Proceeding with the design of electric impedance matching circuit for piezoelectric sensors, actuators, and transducers require careful consideration of the frequencies of operation, transmitter or receiver impedance, power supply or driver impedance and the impedance of the receiver electronics. This paper reviews the techniques available for matching the electric impedance of piezoelectric sensors, actuators, and transducers with their accessories like amplifiers, cables, power supply, receiver electronics and power storage. The techniques related to the design of power supply, preamplifier, cable, matching circuits for electric impedance matching with sensors, actuators, and transducers have been presented. The paper begins with the common tools, models, and material properties used for the design of electric impedance matching. Common analytical and numerical methods used to develop electric impedance matching networks have been reviewed. The role and importance of electrical impedance matching on the overall performance of the transducer system have been emphasized throughout. The paper reviews the common methods and new methods reported for electrical impedance matching for specific applications. The paper concludes with special applications and future perspectives considering the recent advancements in materials and electronics.
      Citation: Electronics
      PubDate: 2019-02-01
      DOI: 10.3390/electronics8020169
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 170: A Cost-Effective Air Quality Supervision
           Solution for Enhanced Living Environments through the Internet of Things

    • Authors: Marques, Pitarma
      First page: 170
      Abstract: We spend about 90% of our lives in indoor living environments. Thus, it is essential to provide indoor air quality monitoring for enhanced living environments. Advances in networking, sensors, and embedded devices have made monitoring and supply of assistance possible to people in their homes. Technological advancements have made possible the building of smart devices with significant capabilities for sensing and connecting, but also provide several improvements in ambient assisted living system architectures. Indoor air quality assumes an important role in building productive and healthy indoor environments. In this paper, the authors present an Internet of Things system for real-time indoor air quality monitoring named iAir. This system is composed by an ESP8266 as the communication and processing unit and a MICS-6814 sensor as the sensing unit. The MICS-6814 is a metal oxide semiconductor sensor capable of detecting several gases such as carbon monoxide, nitrogen dioxide, ethanol, methane, and propane. The iAir system also provides a smartphone application for data consulting and real-time notifications. Compared to other solutions, the iAir system is based on open-source technologies and operates as a totally Wi-Fi system, with several advantages such as its modularity, scalability, low cost, and easy installation. The results obtained are very promising, representing a meaningful contribution for enhanced living environments as iAir provides real-time monitoring for enhanced ambient assisted living and occupational health.
      Citation: Electronics
      PubDate: 2019-02-01
      DOI: 10.3390/electronics8020170
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 171: Dual Authentication-Based Encryption with
           a Delegation System to Protect Medical Data in Cloud Computing

    • Authors: Badr, Zhang, Umar
      First page: 171
      Abstract: The increasing use of cloud computing, especially in commercial, government and healthcare institutions, started with the use of computerized clouds. Clouds store important data, which reduces the cost of management and ensures easy access. To protect this data, cryptographic methods are used to ensure confidentiality of the data, as well as to secure access to user data and increase trust in cloud technology. In our paper, we suggest a new scheme to support an attribute-based encryption system (ABE) that involves multiple parties such as data owners, data users, cloud servers and authority. A verified and authenticated decryption process for the cloud environment is the imperative feature of our proposed architecture. The data owner encrypts their data and sends it to the cloud. The cloud server performs partial decryption and the final decrypted data are shared for users as per their privileges. Thus, the data owner reduces complexity of productivity by delegating the decryption process to the cloud server. Analysis of the experimental results confirms that data access in the electronic cloud atmosphere is safer due to a controlled multiple-users-rights scheme. Our performance evaluation results show that the proposed model condensed the communication overhead and made Digital Imaging and Communications in Medicine (DICOM) more secure.
      Citation: Electronics
      PubDate: 2019-02-01
      DOI: 10.3390/electronics8020171
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 172: An Experimental Study of the Failure Mode
           of ZnO Varistors Under Multiple Lightning Strokes

    • Authors: Chunlong Zhang, Hongyan Xing, Pengfei Li, Chunying Li, Dongbo Lv, Shaojie Yang
      First page: 172
      Abstract: In this study, in order to explore the failure mode of ZnO varistors under multiple lightning strokes, a five-pulse 8/20 μs nominal lightning current with pulse intervals of 50 ms was applied to ZnO varistors. Scanning electron microscopy (SEM) and X-ray diffractometry (XRD) were used to analyze the microstructure of the material. The failure processes of ZnO varistors caused by multiple lightning impulse currents were described. The performance changes of ZnO varistors after multiple lightning impulses were analyzed from both macro and micro perspectives. According to the results of this study’s experiments, the macroscopic failure mode of ZnO varistors after multiple lightning impulses involved the rapid deterioration of the electrical parameters with the increase of the number of impulse groups, until destruction occurred by side-corner cracking. The microstructural examination indicated that, after the multiple lightning strokes, the proportion of Bi in the crystal phases was altered, the grain size of the ZnO varistors became smaller, and the white intergranular phase (Bi-rich grain boundary layer) increased significantly. The failure mechanism was thermal damage and grain boundary structure damage caused by temperature gradient thermal stress, generated by multiple lightning currents.
      Citation: Electronics
      PubDate: 2019-02-02
      DOI: 10.3390/electronics8020172
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 173: A Comparative Study of Markerless Systems
           Based on Color-Depth Cameras, Polymer Optical Fiber Curvature Sensors, and
           Inertial Measurement Units: Towards Increasing the Accuracy in Joint Angle

    • Authors: Nicolas Valencia-Jimenez, Arnaldo Leal-Junior, Leticia Avellar, Laura Vargas-Valencia, Pablo Caicedo-Rodríguez, Andrés A. Ramírez-Duque, Mariana Lyra, Carlos Marques, Teodiano Bastos, Anselmo Frizera
      First page: 173
      Abstract: This paper presents a comparison between a multiple red green blue-depth (RGB-D) vision system, an intensity variation-based polymer optical fiber (POF) sensor, and inertial measurement units (IMUs) for human joint angle estimation and movement analysis. This systematic comparison aims to study the trade-off between the non-invasive feature of a vision system and its accuracy with wearable technologies for joint angle measurements. The multiple RGB-D vision system is composed of two camera-based sensors, in which a sensor fusion algorithm is employed to mitigate occlusion and out-range issues commonly reported in such systems. Two wearable sensors were employed for the comparison of angle estimation: (i) a POF curvature sensor to measure 1-DOF angle; and (ii) a commercially available IMUs MTw Awinda from Xsens. A protocol to evaluate elbow joints of 11 healthy volunteers was implemented and the comparison of the three systems was presented using the correlation coefficient and the root mean squared error (RMSE). Moreover, a novel approach for angle correction of markerless camera-based systems is proposed here to minimize the errors on the sagittal plane. Results show a correlation coefficient up to 0.99 between the sensors with a RMSE of 4.90 ∘ , which represents a two-fold reduction when compared with the uncompensated results (10.42 ∘ ). Thus, the RGB-D system with the proposed technique is an attractive non-invasive and low-cost option for joint angle assessment. The authors envisage the proposed vision system as a valuable tool for the development of game-based interactive environments and for assistance of healthcare professionals on the generation of functional parameters during motion analysis in physical training and therapy.
      Citation: Electronics
      PubDate: 2019-02-02
      DOI: 10.3390/electronics8020173
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 174: Retrieval of Three-Dimensional Surface
           Deformation Using an Improved Differential SAR Tomography System

    • Authors: Zhigui Wang, Mei Liu, Kunfeng Lv
      First page: 174
      Abstract: Conventional differential synthetic aperture radar tomography (D-TomoSAR) can only capture the scatterers’ one-dimensional (1-D) deformation information along the line of sight (LOS) of the synthetic aperture radar (SAR), which means that it cannot retrieve the three-dimensional (3-D) movements of the ground surface. To retrieve the 3-D deformation displacements, several methods have been proposed; the performance is limited due to the insufficient sensitivity for retrieving the North-South motion component. In this paper, an improved D-TomoSAR model is established by introducing the scatterers’ 3-D deformation parameters in slant range, azimuth, and elevation directions into the traditional D-TomoSAR model. The improved D-TomoSAR can be regarded as a multi-component two-dimensional (2-D) polynomial phase signal (PPS). Then, an effective algorithm is proposed to retrieve the 3-D deformation parameters of the ground surface by the 2-D product high-order ambiguity function (PHAF) with the relax (RELAX) algorithm. The estimation performance is investigated and compared with the traditional algorithm. Simulations and experimental results with semi-real data verify the effectiveness of the proposed signal model and algorithm.
      Citation: Electronics
      PubDate: 2019-02-02
      DOI: 10.3390/electronics8020174
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 175: Finite-Time Stabilization for Stochastic
           Interval Systems with Time Delay and Application to Energy-Storing
           Electrical Circuits

    • Authors: Guici Chen, Fei Wei, Wenbo Wang
      First page: 175
      Abstract: In this paper, the problem of stochastic finite-time stabilization is investigated for stochastic delay interval systems. A nonlinear state feedback controller with input-to-state delay is introduced. By employing the Lyapunov–Krasovskii functional method, some sufficient conditions on stochastic finite-time stabilization are derived for closed-loop stochastic delay interval systems using the I t o ^ ’s differential formula. Suitable nonlinear state feedback controllers can be designed in terms of linear matrix inequalities. The obtained results are finally applied to an energy-storing electrical circuit to illustrate the effectiveness of the proposed method.
      Citation: Electronics
      PubDate: 2019-02-02
      DOI: 10.3390/electronics8020175
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 176: An Optimized Methodology for a Hybrid
           Photo-Voltaic and Energy Storage System Connected to a Low-Voltage Grid

    • Authors: Sarvar Hussain Nengroo, Muhammad Umair Ali, Amad Zafar, Sadam Hussain, Tahir Murtaza, Muhammad Junaid Alvi, K.V.G. Raghavendra, Hee Jee Kim
      First page: 176
      Abstract: The growing human population and the increasing energy needs have produced a serious energy crisis, which has stimulated researchers to look for alternative energy sources. The diffusion of small-scale renewable distributed generations (DG) with micro-grids can be a promising solution to meet the environmental obligations. The uncertainty and sporadic nature of renewable energy sources (RES) is the main obstacle to their use as autonomous energy sources. In order to overcome this, a storage system is required. This paper proposes an optimized strategy for a hybrid photovoltaic (PV) and battery storage system (BSS) connected to a low-voltage grid. In this study, a cost function is formulated to minimize the net cost of electricity purchased from the grid. The charging and discharging of the battery are operated optimally to minimize the defined cost function. Half-hourly electricity consumer load data and solar irradiance data collected from the United Kingdom (UK) for a whole year are utilized in the proposed methodology. Five cases are discussed for a comparative cost analysis of the electricity imported and exported. The proposed scheme provides a techno-economic analysis of the combination of a BSS with a low-voltage grid, benefitting from the feed-in tariff (FIT) scheme.
      Citation: Electronics
      PubDate: 2019-02-02
      DOI: 10.3390/electronics8020176
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 177: A Smart Many-Core Implementation of a
           Motion Planning Framework along a Reference Path for Autonomous Cars

    • Authors: Gianpiero Cabodi, Paolo Camurati, Alessandro Garbo, Michele Giorelli, Stefano Quer, Francesco Savarese
      First page: 177
      Abstract: Research on autonomous cars, early intensified in the 1990s, is becoming one of the main research paths in automotive industry. Recent works use Rapidly-exploring Random Trees to explore the state space along a given reference path, and to compute the minimum time collision-free path in real time. Those methods do not require good approximations of the reference path, they are able to cope with discontinuous routes, they are capable of navigating in realistic traffic scenarios, and they derive their power from an extensive computational effort directed to improve the quality of the trajectory from step to step. In this paper, we focus on re-engineering an existing state-of-the-art sequential algorithm to obtain a CUDA-based GPGPU (General Purpose Graphics Processing Units) implementation. To do that, we show how to partition the original algorithm among several working threads running on the GPU, how to propagate information among threads, and how to synchronize those threads. We also give detailed evidence on how to organize memory transfers between the CPU and the GPU (and among different CUDA kernels) such that planning times are optimized and the available memory is not exceeded while storing massive amounts of fuse data. To sum up, in our application the GPU is used for all main operations, the entire application is developed in the CUDA language, and specific attention is paid to concurrency, synchronization, and data communication. We run experiments on several real scenarios, comparing the GPU implementation with the CPU one in terms of the quality of the generated paths and in terms of computation (wall-clock) times. The results of our experiments show that embedded GPUs can be used as an enabler for real-time applications of computationally expensive planning approaches.
      Citation: Electronics
      PubDate: 2019-02-02
      DOI: 10.3390/electronics8020177
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 178: On the Design of Low-Cost IoT Sensor Node
           for e-Health Environments

    • Authors: Nikos Petrellis, Michael Birbas, Fotios Gioulekas
      First page: 178
      Abstract: The proliferation of Internet of Things (IoT) devices for patient monitoring has gained much attention in clinical care performance, proficient chronic disease management, and home caregiving. This work presents the design of efficient medical IoT sensor nodes (SNs) in terms of low-cost, low power-consumption, and increased data accuracy based on open-source platforms. The method utilizes a Sensor Controller (SC) within the IoT SN, which is capable of performing medical checks supporting a broad coverage of medical uses. A communication protocol has been developed for data and command exchange among SC, local gateways, and physicians’ or patients’ mobile devices (tablets, smart phones). The SC supports moving average window (MAW) and principle component analysis (PCA) filtering algorithms to capture data from the attached low-cost body sensors of different sampling profiles. Significant extensions in SN’s portability is achieved through energy consumption minimization based on the idle time gaps between sensors’ activations. SN’s components are either deactivated or set to low activity operation during these idle intervals. A medical case study is presented and the evaluated results show that the proposed SN can be incorporated into e-health platforms since it achieves comparable accuracy to its certified and high-cost commercial counterparts.
      Citation: Electronics
      PubDate: 2019-02-02
      DOI: 10.3390/electronics8020178
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 179: A Current Reconstruction at Parallel Three
           Phase Inverters Using Two Current Sensors

    • Authors: Kim, Han, Wang, Wang, Cho
      First page: 179
      Abstract: In this paper, a current restoration method which can be applied to three phase parallel interleaved inverters (TPPII) using two current sensors has been proposed. In the proposed current reconstruction method, the branch current and the phase current of the two phases of the TPPII are sampled concurrently at the peak and valley of the pulse width modulation (PWM) carrier using two hall-effect sensors. Then, the phase current of each inverter is reconstructed by analyzing the sensed current with the current conduction path information according to the switch state in the peak and valley of the PWM carrier. This paper additionally analyzes the characteristics of the offset occurring in the detection process of two current sensors and it proposes a compensation method to reduce the offset on-line. In order to at once reduce the offset of the three-phase recovery current caused by the DC offset of the sensor, a coordinate conversion method and a low pass are used. To verify the performance of the proposed current recovery method and real-time offset compensation method, a simulation using PSIM software was performed, and experiments were conducted using a three phase parallel inverter composed of insulated gate bipolar transistor (IGBT) modules. In particular, the AC offset that occurred in the sampling process during the experiment was analyzed and modeled, and it was reduced by simple calculation.
      Citation: Electronics
      PubDate: 2019-02-04
      DOI: 10.3390/electronics8020179
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 180: A Weighted-Sum PSO Algorithm for HEMS: A
           New Approach for the Design and Diversified Performance Analysis

    • Authors: Bilal Hussain, Asif Khan, Nadeem Javaid, Qadeer Ul Hasan, Shahzad Malik, Amir Hanif Dar, Ahmad Kazmi, Omar Ahmad
      First page: 180
      Abstract: This research focuses on a decomposed-weighted-sum particle swarm optimization (DWS-PSO) approach that is proposed for optimal operations of price-driven demand response (PDDR) and PDDR-synergized with the renewable and energy storage dispatch (PDDR-RED) based home energy management systems (HEMSs). The algorithm for PDDR-RED-based HEMS is developed by combining a DWS-PSO-based PDDR scheme for load shifting with the dispatch strategy for the photovoltaic (PV), storage battery (SB), and power grid systems. Shiftable home appliances (SHAs) are modeled for mixed scheduling (MS). The MS includes advanced as well as delayed scheduling (AS/DS) of SHAs to maximize the reduction in the net cost of energy ( C E ). A set of weighting vectors is deployed while implementing algorithms and a multi-objective-optimization (MOO) problem is decomposed into single-objective sub-problems that are optimized simultaneously in a single run. Furthermore, an innovative method to carry out the diversified performance analysis (DPA) of the proposed algorithms is also proposed. The method comprises the construction of a diversified set of test problems (TPs), defining of performance metrics, and computation of the metrics. The TPs are constructed for a set of standardized dynamic pricing signal and for scheduling models for MS and DS. The simulation results show the gradient of the tradeoff line for the reduction in C E and related discomfort for DPA.
      Citation: Electronics
      PubDate: 2019-02-04
      DOI: 10.3390/electronics8020180
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 181: A Mixed Deep Recurrent Neural Network for
           MEMS Gyroscope Noise Suppressing

    • Authors: Jiang, Chen, Chen, Bo, Li, Tian, Guo
      First page: 181
      Abstract: Currently, positioning, navigation, and timing information is becoming more and more vital for both civil and military applications. Integration of the global navigation satellite system and /inertial navigation system is the most popular solution for various carriers or vehicle positioning. As is well-known, the global navigation satellite system positioning accuracy will degrade in signal challenging environments. Under this condition, the integration system will fade to a standalone inertial navigation system outputting navigation solutions. However, without outer aiding, positioning errors of the inertial navigation system diverge quickly due to the noise contained in the raw data of the inertial measurement unit. In particular, the micromechanics system inertial measurement unit experiences more complex errors due to the manufacturing technology. To improve the navigation accuracy of inertial navigation systems, one effective approach is to model the raw signal noise and suppress it. Commonly, an inertial measurement unit is composed of three gyroscopes and three accelerometers, among them, the gyroscopes play an important role in the accuracy of the inertial navigation system’s navigation solutions. Motivated by this problem, in this paper, an advanced deep recurrent neural network was employed and evaluated in noise modeling of a micromechanics system gyroscope. Specifically, a deep long short term memory recurrent neural network and a deep gated recurrent unit–recurrent neural network were combined together to construct a two-layer recurrent neural network for noise modeling. In this method, the gyroscope data were treated as a time series, and a real dataset from a micromechanics system inertial measurement unit was employed in the experiments. The results showed that, compared to the two-layer long short term memory, the three-axis attitude errors of the mixed long short term memory–gated recurrent unit decreased by 7.8%, 20.0%, and 5.1%. When compared with the two-layer gated recurrent unit, the proposed method showed 15.9%, 14.3%, and 10.5% improvement. These results supported a positive conclusion on the performance of designed method, specifically, the mixed deep recurrent neural networks outperformed than the two-layer gated recurrent unit and the two-layer long short term memory recurrent neural networks.
      Citation: Electronics
      PubDate: 2019-02-04
      DOI: 10.3390/electronics8020181
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 182: On Energy Efficiency and Performance
           Evaluation of Single Board Computer Based Clusters: A Hadoop Case Study

    • Authors: Basit Qureshi, Anis Koubaa
      First page: 182
      Abstract: Energy efficiency in a data center is a challenge and has garnered researchers interest. In this study, we addressed the energy efficiency issue of a small scale data center by utilizing Single Board Computer (SBC)-based clusters. A compact layout was designed to build two clusters using 20 nodes each. Extensive testing was carried out to analyze the performance of these clusters using popular performance benchmarks for task execution time, memory/storage utilization, network throughput and energy consumption. Further, we investigated the cost of operating SBC-based clusters by correlating energy utilization for the execution time of various benchmarks using workloads of different sizes. Results show that, although the low-cost benefit of a cluster built with ARM-based SBCs is desirable, these clusters yield low comparable performance and energy efficiency due to limited onboard capabilities. It is possible to tweak Hadoop configuration parameters for an ARM-based SBC cluster to efficiently utilize resources. We present a discussion on the effectiveness of the SBC-based clusters as a testbed for inexpensive and green cloud computing research.
      Citation: Electronics
      PubDate: 2019-02-04
      DOI: 10.3390/electronics8020182
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 183: Toward Network Worm Victims Identification
           Based on Cascading Motif Discovery

    • Authors: Hangyu Hu, Mingda Wang, Mingyu Ouyang, Guangmin Hu
      First page: 183
      Abstract: Network worms spread widely over the global network within a short time, which are increasingly becoming one of the most potential threats to network security. However, the performance of traditional packet-oriented signature-based methods is questionable in the face of unknown worms, while anomaly-based approaches often exhibit high false positive rates. It is a common scenario that the life cycle of network worms consists of the same four stages, in which the target discovery phase and the transferring phase have specific interactive patterns. To this end, we propose Network Flow Connectivity Graph (NFCG) for identifying network worm victims. We model the flow-level interactions as graph and then identify sets of frequently occurring motifs related to network worms through Cascading Motif Discovery algorithm. In particular, a cascading motif is jointly extracted from graph target discovery phase and transferring phase. If a cascading motif exists in a connected behavior graph of one host, the host would be identified as a suspicious worm victim; the excess amount of suspicious network worm victims is used to reveal the outbreak of network worms. The simulated experiments show that our proposed method is effective and efficient in network worm victims’ identification and helpful for improving network security.
      Citation: Electronics
      PubDate: 2019-02-05
      DOI: 10.3390/electronics8020183
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 184: Bio-inspired Autonomous Visual Vertical
           and Horizontal Control of a Quadrotor Unmanned Aerial Vehicle

    • Authors: Saul Armendariz, Victor Becerra, Nils Bausch
      First page: 184
      Abstract: Near-ground manoeuvres, such as landing, are key elements in unmanned aerial vehicle navigation. Traditionally, these manoeuvres have been done using external reference frames to measure or estimate the velocity and the height of the vehicle. Complex near-ground manoeuvres are performed by flying animals with ease. These animals perform these complex manoeuvres by exclusively using the information from their vision and vestibular system. In this paper, we use the Tau theory, a visual strategy that, is believed, is used by many animals to approach objects, as a solution for relative ground distance control for unmanned vehicles. In this paper, it is shown how this approach can be used to perform near-ground manoeuvres in a vertical and horizontal manner on a moving target without the knowledge of height and velocity of either the vehicle or the target. The proposed system is tested with simulations. Here, it is shown that, using the proposed methods, the vehicle is able to perform landing on a moving target, and also they enable the user to choose the dynamic characteristics of the approach.
      Citation: Electronics
      PubDate: 2019-02-05
      DOI: 10.3390/electronics8020184
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 185: A Hybrid Dead Reckon System Based on
           3-Dimensional Dynamic Time Warping

    • Authors: Jian Chen, Gang Ou, Ao Peng, Lingxiang Zheng, Jianghong Shi
      First page: 185
      Abstract: In recent years, using smartphones for indoor positioning has become increasingly popular with consumers. This paper presents an integrated localization technique for inertial and magnetic field sensors to challenge indoor positioning without Wi-Fi signals. For dead-reckoning (DR), attitude angle estimation, step length calculation, and step counting estimation are introduced. Dynamic time warping (DTW) usually calculates the distance between the measured magnetic field and magnetic fingerprint in the database. For DR/Magnetic matching (MM), we creatively propose 3-dimensional dynamic time warping (3DDTW) to calculate the distance. Unlike traditional DTW, 3DDTW extends the original one-dimensional signal to a two-dimensional signal. Finally, the weighted least squares further improves indoor positioning accuracy. In the three different experimental scenarios—teaching building, study room, office building—DR/MM hybrid positioning accuracy is about 3.34 m.
      Citation: Electronics
      PubDate: 2019-02-05
      DOI: 10.3390/electronics8020185
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 186: RPL Routing Protocol Performance in Smart
           Grid Applications Based Wireless Sensors: Experimental and Simulated

    • Authors: Shimaa A. Abdel Hakeem, Anar A. Hady, Kim
      First page: 186
      Abstract: The Advanced Metering Infrastructure (AMI) is one of the Smart Grid (SG) applications that used to upgrade the current power system by proposing a two-way communication system to connect the smart meter devices at homes with the electric control company. The design and deployment of an efficient routing protocol solution for AMI systems are considered to be a critical challenge due to the constrained resources of the smart meter nodes. IPv6 Routing Protocol for Low Power and Lossy Networks (RPL) was recently standardized by the IETF and originally designed to satisfy the routing requirements of lossy and low power networks like wireless sensors (WSN). We have two kinds of AMI applications, on one hand AMI based WSN and on the other hand AMI based PLC communication. In this paper, we proposed a real and simulated implementation of RPL behavior with proper modifications to support the AMI based WSN routing requirements. We evaluate RPL performance using 140 nodes from the wireless sensor testbed (IoT-LAB) and 1000 nodes using Cooja simulator measure RPL performance within medium and high-density networks. We adopted two routing metrics for path selection: First one is HOP Count (HC) and the second is Expected Transmission Unit (ETX) to evaluate RPL performance in terms of packet delivery ratio; network latency; control traffic overhead; and power consumption. Our results illustrate that routes with ETX calculations in low and medium network densities outperform routes using HC and the performance decreases as the network becomes dense. However, Cooja implementation results provides an average reasonable performance for AMI with high-density networks; still many RPL nodes suffering from high packet loss rates, network congestion and many retransmissions due to the selection of optimal paths with highly unreliable links.
      Citation: Electronics
      PubDate: 2019-02-05
      DOI: 10.3390/electronics8020186
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 187: Structural Improvements in Consensus-Based
           Cooperative Control of DC Microgrids

    • Authors: Mumtaz, khan, Fang, Shahid, Faiz
      First page: 187
      Abstract: This study is dedicated to establishing a comparative analysis of the performance ofdifferent local controllers on the cooperative control of DC microgrids. One of the elementary andchallenging issues in DC microgrids is the assurance of fairness in proportional current sharingwhile accomplishing voltage regulation in parallelly connected distributed energy sources. In thiswork, structural improvements are proposed to enhance the system stability and controlperformance. A finite-gain controller was employed in the outer voltage control loop with a simpleproportional (P) controller in the inner current control loop of a converter. Due to the finite-gaincontroller, droop-like power sharing was achieved without droop coefficient. In order to furtherenhance the power-sharing accuracy and DC voltage regulation, a different method was adopted inconsensus-based cooperative control to estimate the average current and average voltage difference.Moreover, small signal analysis was used to scrutinize the stability and control performance of thelocal controller, while different communication delays and current disturbances were applied toexamine the performance of the controller. Finally, a four-node-based DC microgrid setup wasdeveloped in MATLAB/Simulink environment, and simulation results of the proposed and existingtechniques were scrutinized. The simulations results demonstrated the effectiveness of the proposedcontroller.
      Citation: Electronics
      PubDate: 2019-02-06
      DOI: 10.3390/electronics8020187
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 188: Multi-Radio Integrated Navigation System
           M&S Software Design for GNSS Backup under Navigation Warfare

    • Authors: Kim, Lee, Oh, So, Hwang
      First page: 188
      Abstract: To avoid degradation of navigation performance in the navigation warfare environment, the multi-radio integrated navigation system can be used, in which all available radio navigation systems are integrated to back up Global Navigation Satellite System (GNSS) when the GNSS is not available. Before real-time multi-radio integrated navigation systems are deployed, time and cost can be saved when the modeling and simulation (M&S) software is used in the performance evaluation. When the multi-radio integrated navigation system M&S is comprised of independent function modules, it is easy to modify and/or to replace the function modules. In this paper, the M&S software design method was proposed for multi-radio integrated navigation systems as a GNSS backup under the navigation warfare. The M&S software in the proposed design method consists of a message broker and function modules. All the messages were transferred through the message broker in order to be exchanged between the function modules. The function modules in the M&S software were independently operated due to the message broker. A message broker-based M&S software was designed for a multi-radio integrated navigation system. In order to show the feasibility of the proposed design method, the M&S software was implemented for Global Positioning System (GPS), Korean Navigation Satellite System (KNSS), enhanced Long range navigation (eLoran), Loran-C, and Distance Measuring Equipment/Very high-frequency Omnidirectional Radio range (DME/VOR). The usefulness of the proposed design method was shown by checking the accuracy and availability of the GPS only navigation and the multi-radio integrated navigation system under the attack of jamming to GPS.
      Citation: Electronics
      PubDate: 2019-02-06
      DOI: 10.3390/electronics8020188
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 189: Regulating Scheduler (RSC): A Novel
           Solution for IEEE 802.1 Time Sensitive Network (TSN)

    • Authors: Joung
      First page: 189
      Abstract: Emerging applications such as industrial automation, in-vehicle, professional audio-video, and wide area electrical utility networks require strict bounds on the end-to-end network delay. Solutions so far to such a requirement are either impractical or ineffective. Flow based schedulers suggested in a traditional integrated services (IntServ) framework are O(N) or O(log N), where N is the number of flows in the scheduler, which can grow to tens of thousands in a core router. Due to such complexity, class-based schedulers are adopted in real deployments. The class-based systems, however, cannot provide bounded delays in networks with cycle, since the maximum burst grows infinitely along the cycled path. Attaching a regulator in front of a scheduler to limit the maximum burst is considered as a viable solution. International standards, such as IEEE 802.1 time sensitive network (TSN) and IETF deterministic network (DetNet) are adopting this approach as a standard. The regulator in TSN and DetNet, however, requires flow state information, therefore contradicts to the simple class-based schedulers. This paper suggests non-work conserving fair schedulers, called ‘regulating schedulers’ (RSC), which function as a regulator and a scheduler at the same time. A deficit round-robin (DRR) based RSC, called nw-DRR, is devised and proved to be both a fair scheduler and a regulator. Despite the lower complexity, the input port-based nw-DRR is shown to perform better than the current TSN approach, and to bind the end-to-end delay within a few milliseconds in realistic network scenarios.
      Citation: Electronics
      PubDate: 2019-02-06
      DOI: 10.3390/electronics8020189
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 190: An Alternative Carrier-Based
           Implementation of Space Vector Modulation to Eliminate Common Mode Voltage
           in a Multilevel Matrix Converter

    • Authors: Rząsa
      First page: 190
      Abstract: The main aim of the paper is to find a control method for a multilevel matrix converter (MMC) that enables the elimination of common mode voltage (CMV). The method discussed in the paper is based on a selection of converter configurations and the instantaneous output voltages of MMC represented by rotating space vectors. The choice of appropriate configurations is realized by the use of space vector modulation (SVM), with the application of Venturini modulation functions. A multilevel matrix converter, which utilizes a multilevel structure in a traditional matrix converter (MC), can achieve an improved output voltage waveform quality, compared with the output voltage of MC. The carrier-based implementation of SVM is presented in this paper. The carrier-based implementation of SVM avoids any trigonometric and division operations, which could be required in a general space vector approach to the SVM method. With use of the proposed control method, a part of the high-frequency output voltage distortion components is eliminated. The application of the presented modulation method eliminates the CMV in MMC what is presented in the paper. Additionally, the possibility to control the phase shift between the appropriate input and output phase voltages is obtained by the presented control strategy. The results of the simulation and experiment confirm the utility of the proposed modulation method.
      Citation: Electronics
      PubDate: 2019-02-06
      DOI: 10.3390/electronics8020190
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 191: Enhanced Dual-Spectrum Line Interpolated
           FFT with Four-Term Minimal Sidelobe Cosine Window for Real-Time Harmonic
           Estimation in Synchrophasor Smart-Grid Technology

    • Authors: Oruganti, Dhanikonda, Paredes, Simões
      First page: 191
      Abstract: The proliferation of nonlinear loads and integration of renewable energy sources require attention for accurate harmonic estimation along with estimation of fundamental amplitude, phase, and frequency for protection, improving power quality, and managing power effectively in a smart distribution grid. There are currently different Windowed Interpolated Fast Fourier Transform (WIFFT) algorithms for harmonic voltage estimation, but estimation of current harmonics using WIFFT is not explored sufficiently. The existing WIFFT algorithms, when used for current harmonic estimation result in low accuracy due to spectral leakage and picket fence effect. On the other hand, Interpolated Discrete Fourier Transform (DFT) is used for synchrophasor quality metrics, but it is effective only when there are no harmonics and the fundamental frequency is constant. This paper proposes a unified solution, comprising of peak location index search (PLIS)-based Dual-Spectrum Line Interpolated Fast Fourier Transform (DSLIFFT) algorithm with 4-Term Minimal Sidelobe Cosine Window (4MSCW) for estimating both low-amplitude voltage or current harmonics and synchrophasor under variable frequency conditions for high-penetration renewable energy utility grids. The effectiveness of the proposed algorithm is validated by simulation studies and real-time experimentation using the National Instruments reconfigurable embedded system under nonlinear loading conditions.
      Citation: Electronics
      PubDate: 2019-02-06
      DOI: 10.3390/electronics8020191
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 192: Using Wearable ECG/PPG Sensors for Driver

    • Authors: Lee, Lee, Shin
      First page: 192
      Abstract: This paper aims to investigate the robust and distinguishable pattern of heart rate variability (HRV) signals, acquired from wearable electrocardiogram (ECG) or photoplethysmogram (PPG) sensors, for driver drowsiness detection. As wearable sensors are so vulnerable to slight movement, they often produce more noise in signals. Thus, from noisy HRV signals, we need to find good traits that differentiate well between drowsy and awake states. To this end, we explored three types of recurrence plots (RPs) generated from the R–R intervals (RRIs) of heartbeats: Bin-RP, Cont-RP, and ReLU-RP. Here Bin-RP is a binary recurrence plot, Cont-RP is a continuous recurrence plot, and ReLU-RP is a thresholded recurrence plot obtained by filtering Cont-RP with a modified rectified linear unit (ReLU) function. By utilizing each of these RPs as input features to a convolutional neural network (CNN), we examined their usefulness for drowsy/awake classification. For experiments, we collected RRIs at drowsy and awake conditions with an ECG sensor of the Polar H7 strap and a PPG sensor of the Microsoft (MS) band 2 in a virtual driving environment. The results showed that ReLU-RP is the most distinct and reliable pattern for drowsiness detection, regardless of sensor types (i.e., ECG or PPG). In particular, the ReLU-RP based CNN models showed their superiority to other conventional models, providing approximately 6–17% better accuracy for ECG and 4–14% for PPG in drowsy/awake classification.
      Citation: Electronics
      PubDate: 2019-02-07
      DOI: 10.3390/electronics8020192
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 193: Full-Band Oversized Turnstile-Based
           Waveguide Four-Way Power Divider/Combiner for High-Power Applications

    • Authors: Juan Luis Cano, Franco Di Paolo, Angel Mediavilla, Paolo Colantonio
      First page: 193
      Abstract: Very high-power and high-efficiency microwave applications require waveguide structures to combine/divide the power from/to a variable number of high-power solid-state devices. In the literature, among the different waveguide configurations, those capable of providing the maximum output power show a limited relative bandwidth. To overcome this limitation, in this paper a full-band (40%) waveguide power divider/combiner specifically designed for high-power applications (up to several kW) is presented. The proposed structure uses an evolved turnstile junction with a standard rectangular waveguide common port, rotated 45°, with respect to its central axis, to divide/combine the signal to/from the four output/input rectangular ports. The inclusion of an oversized central cavity together with circular and rectangular waveguide impedance transformers at the common port allows the achievement of a full-band operation with excellent electrical performance, while maintaining a very simple and compact configuration. Only two layers of metal are required for the physical implementation of this structure in platelet configuration. A prototype has been designed covering the full Ka-band (26.5–40 GHz), showing an excellent measured performance with around 30 dB of return loss, 0.18 dB of insertion loss, and less than 1.5° of phase imbalance.
      Citation: Electronics
      PubDate: 2019-02-07
      DOI: 10.3390/electronics8020193
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 194: Multilayer Perceptron Neural Network-Based
           QoS-Aware, Content-Aware and Device-Aware QoE Prediction Model: A Proposed
           Prediction Model for Medical Ultrasound Streaming Over Small Cell Networks

    • Authors: Ikram U. Rehman, Moustafa M. Nasralla, Nada Y. Philip
      First page: 194
      Abstract: This paper presents a QoS-aware, content-aware and device-aware nonintrusive medical QoE (m-QoE) prediction model over small cell networks. The proposed prediction model utilises a Multilayer Perceptron (MLP) neural network to predict m-QoE. It also acts as a platform to maintain and optimise the acceptable diagnostic quality through a device-aware adaptive video streaming mechanism. The proposed model is trained for an unseen dataset of input variables such as QoS, content features and display device characteristics, to produce an output value in the form of m-QoE (i.e. MOS). The efficiency of the proposed model is validated through subjective tests carried by medical experts. The prediction accuracy obtained via the correlation coefficient and Root Mean-Square-Error (RMSE) indicates that the proposed model succeeds in measuring m-QoE closer to the visual perception of the medical experts. Furthermore, we have addressed two main research questions: (1) How significant is ultrasound video content type in determining m-QoE' (2) How much of a role does the screen size and device resolution play in medical experts’ diagnostic experience' The former is answered through the content classification of ultrasound video sequences based on their spatiotemporal features, by including these features in the proposed prediction model, and validating their significance through medical experts’ subjective ratings. The latter is answered by conducting a novel subjective experiment of the ultrasound video sequences across multiple devices.
      Citation: Electronics
      PubDate: 2019-02-07
      DOI: 10.3390/electronics8020194
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 195: Pre- and Post-Processing Algorithms with
           Deep Learning Classifier for Wi-Fi Fingerprint-Based Indoor Positioning

    • Authors: Haider, Wei, Liu, Hwang
      First page: 195
      Abstract: To accommodate the rapidly increasing demand for connected infrastructure, automation for industrial sites and building smart cities, the development of Internet of Things (IoT)-based solutions is considered one of the major trends in modern day industrial revolution. In particular, providing high precision indoor positioning services for such applications is a key challenge. Wi-Fi fingerprint-based indoor positioning systems have been adapted as promising candidates for such applications. The performance of such indoor positioning systems degrade drastically due to several impairments like noisy datasets, high variation in Wi-Fi signals over time, fading of Wi-Fi signals due to multipath propagation caused by hurdles, people walking in the area under consideration and the addition/removal of Wi-Fi access points (APs). In this paper, we propose data pre- and post-processing algorithms with deep learning classifiers for Wi-Fi fingerprint-based indoor positioning, in order to provide immunity against limitations in the database and the indoor environment. In addition, we investigate the performance of the proposed system through simulation as well as extensive experiments. The results demonstrate that the pre-processing algorithm can efficiently fill in the missing Wi-Fi received signal strength fingerprints in the database, resulting in a success rate of 88.96% in simulation and 86.61% in a real-time experiment. The post-processing algorithm can improve the results from 9.05–10.94% for the conducted experiments, providing the highest success rate of 95.94% with a precision of 4 m for Wi-Fi fingerprint-based indoor positioning.
      Citation: Electronics
      PubDate: 2019-02-08
      DOI: 10.3390/electronics8020195
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 196: Control Strategies of Mitigating Dead-time
           Effect on Power Converters: An Overview

    • Authors: Ji, Yang, Zhou, Ding, Guo, Padmanaban
      First page: 196
      Abstract: To prevent short-circuits between the upper and lower switches of power converters from over-current protection, the dead time is mandatory in the switching gating signal for voltage source converters. However, this results in many negative effects on system operations, such as output voltage and current distortions (e.g., increased level of fifth and seventh harmonics), zero-current-clamping phenomenon, and output fundamental-frequency voltage reduction. Many solutions have been presented to cope with this problem. First, the dead-time effect is analyzed by taking into account factors such as the zero-clamping phenomenon, voltage drops on diodes and transistors, and the parameters of inverter loads, as well as the parasitic nature of semiconductor switches. Second, the state-of-the-art dead-time compensation algorithms are presented in this paper. Third, the advantages and disadvantages of existing algorithms are discussed, together with the future trends of dead-time compensation algorithms. This article provides a complete scenario of dead-time compensation with control strategies for voltage source converters for researchers to identify suitable solutions based on demand and application.
      Citation: Electronics
      PubDate: 2019-02-08
      DOI: 10.3390/electronics8020196
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 197: Active Power Decoupling for Current Source
           Converters: An Overview Scenario

    • Authors: Zhang, Ding, Wang, Guo, Padmanaban
      First page: 197
      Abstract: For single-phase current source converters, there is an inherent limitation in DC-side low-frequency power oscillation, which is twice the grid fundamental frequency. In practice, it transfers to the DC side and results in the low-frequency DC-link ripple. One possible solution is to install excessively large DC-link inductance for attenuating the ripple. However, it is of bulky size and not cost-effective. Another method is to use the passive LC branch for bypassing the power decoupling, but this is still not cost-effective due to the low-frequency LC circuit. Recently, active power decoupling techniques for the current source converters have been sparsely reported in literature. However, there has been no attempt to classify and understand them in a systematic way so far. In order to fill this gap, an overview of the active power decoupling for single-phase current source converters is presented in this paper. Systematic classification and comparison are provided for researchers and engineers to select the appropriate solutions for their specific applications.
      Citation: Electronics
      PubDate: 2019-02-08
      DOI: 10.3390/electronics8020197
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 198: Control System in Open-Source FPGA for a
           Self-Balancing Robot

    • Authors: Juan Ordóñez Cerezo, Encarnación Castillo Morales, José María Cañas Plaza
      First page: 198
      Abstract: Computing in technological applications is typically performed with software running on general-purpose microprocessors, such as the Computer Processing Unit (CPU), or specific ones, like the Graphical Processing Unit (GPU). Application-Specific Integrated Circuits (ASICs) are an interesting option when speed and reliability are required, but development costs are usually high. Field-Programmable Gate Arrays (FPGA) combine the flexibility of software with the high-speed operation of hardware, and can keep costs low. The dominant FPGA infrastructure is proprietary, but open tools have greatly improved and are a growing trend, from which robotics can benefit. This paper presents a robotics application that was fully developed using open FPGA tools. An inverted pendulum robot was designed, built, and programmed using open FPGA tools, such as IceStudio and the IceZum Alhambra board, which integrates the iCE40HX4K-TQ144 from Lattice. The perception from an inertial sensor is used in a PD control algorithm that commands two DC motors. All the modules were synthesized in an FPGA as a proof of concept. Its experimental validation shows good behavior and performance.
      Citation: Electronics
      PubDate: 2019-02-09
      DOI: 10.3390/electronics8020198
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 199: Vehicle Sideslip Angle Estimation Based on
           Tire Model Adaptation

    • Authors: Singh
      First page: 199
      Abstract: Information about the vehicle sideslip angle is crucial for the successful implementation of advanced stability control systems. In production vehicles, sideslip angle is difficult to measure within the desired accuracy level because of high costs and other associated impracticalities. This paper presents a novel framework for estimation of the vehicle sideslip angle. The proposed algorithm utilizes an adaptive tire model in conjunction with a model-based observer. The proposed adaptive tire model is capable of coping with changes to the tire operating conditions. More specifically, extensions have been made to Pacejka's Magic Formula expressions for the tire cornering stiffness and peak grip level. These model extensions account for variations in the tire inflation pressure, load, tread depth and temperature. The vehicle sideslip estimation algorithm is evaluated through experimental tests done on a rear wheel drive (RWD) vehicle. Detailed experimental results show that the developed system can reliably estimate the vehicle sideslip angle during both steady state and transient maneuvers.
      Citation: Electronics
      PubDate: 2019-02-09
      DOI: 10.3390/electronics8020199
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 200: Design of an Open Platform for
           Multi-Disciplinary Approach in Project-Based Learning of an EPICS Class

    • Authors: Ngo, Phan
      First page: 200
      Abstract: Nowadays, global engineers need to be equipped with professional skills and knowledge to solve 21st century problems. The educational program, created in digital learning rooms of the Higher Engineering Education Alliance Program (HEEAP) program supported by Arizona State University, became a pioneer in teaching learners to work within the community. First, the combination of a novel instructional strategy and an integrated education in which project-based approach is employed to apply the technical knowledge. During this, students in mechatronics, computer science, and mechanics must collaborate with peers from industrial systems engineering. Second, in this paper, the design of an open structure connecting multi-disciplinary major is illustrated with a new teaching approach. It is proved to be better by combining specialized understandings of various types in a wide range of applications. From this basis support, participants could implement additional components quickly while keeping the cost low, making the products feasible and user-friendly. Last but not least, students are facilitated with a free library that helps to control simply despite lacking experience in robotics or automation. Several examples show that students are capable of developing things by themselves on open design. In brief, this platform might be an excellent tool to teach and visualize the practical scenario in a multi-disciplinary field.
      Citation: Electronics
      PubDate: 2019-02-10
      DOI: 10.3390/electronics8020200
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 201: Robot Motion Planning in an Unknown
           Environment with Danger Space

    • Authors: Jahanshahi, Jafarzadeh, Sari, Pham, Huynh, Nguyen
      First page: 201
      Abstract: This paper discusses the real-time optimal path planning of autonomous humanoid robots in unknown environments regarding the absence and presence of the danger space. The danger is defined as an environment which is not an obstacle nor free space and robot are permitted to cross when no free space options are available. In other words, the danger can be defined as the potentially risky areas of the map. For example, mud pits in a wooded area and greasy floor in a factory can be considered as a danger. The synthetic potential field, linguistic method, and Markov decision processes are methods which have been reviewed for path planning in a free-danger unknown environment. The modified Markov decision processes based on the Takagi–Sugeno fuzzy inference system is implemented to reach the target in the presence and absence of the danger space. In the proposed method, the reward function has been calculated without the exact estimation of the distance and shape of the obstacles. Unlike other existing path planning algorithms, the proposed methods can work with noisy data. Additionally, the entire motion planning procedure is fully autonomous. This feature makes the robot able to work in a real situation. The discussed methods ensure the collision avoidance and convergence to the target in an optimal and safe path. An Aldebaran humanoid robot, NAO H25, has been selected to verify the presented methods. The proposed methods require only vision data which can be obtained by only one camera. The experimental results demonstrate the efficiency of the proposed methods.
      Citation: Electronics
      PubDate: 2019-02-10
      DOI: 10.3390/electronics8020201
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 202: A Novel SWB Antenna with Triple
           Band-Notches Based on Elliptical Slot and Rectangular Split Ring

    • Authors: Zhang, Rahman, Cao, Gil, khan
      First page: 202
      Abstract: In this paper, a wideband antenna was designed for super-wideband (SWB) applications. The proposed antenna was fed with a rectangular tapered microstrip feed line, which operated over a SWB frequency range (1.42 GHz to 50 GHz). The antenna was implemented at a compact size with electrical dimensions of 0.16 λ × 0.27 λ × 0.0047 λ mm3, where λ was with respect to the lowest resonance frequency. The proposed antenna prototype was fabricated on a F4B substrate, which had a permittivity of 2.65 and 1 mm thickness. The SWB antenna exhibited an impedance bandwidth of 189% and a bandwidth ratio of 35.2:1. Additionally, the proposed antenna design exhibited three band notch characteristics that were necessary to eradicate interference from WLAN, WiMAX, and X bands in the SWB range. One notch was achieved by etching an elliptical split ring resonator (ESRR) in the radiator and the other two notches were achieved by placing rectangular split ring resonators close to the signal line. The first notch was tuned by incorporating a varactor diode into the ESRR. The prototype was experimentally validated with, with notch and without notch characteristics for SWB applications. The experimental results showed good agreement with simulated results.
      Citation: Electronics
      PubDate: 2019-02-10
      DOI: 10.3390/electronics8020202
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 203: 3D Printing Using a 60 GHz Millimeter Wave
           Segmented Parabolic Reflective Curved Antenna

    • Authors: Cai, Sun, Lei
      First page: 203
      Abstract: This paper proposes a segmented parabolic curved antenna, which can be used in the base station of a 60 GHz millimeter wave communication system, with an oblique Yagi antenna as a feed. By analyzing the reflection and multi-path interference cancellation phenomenon when the main lobe of the Yagi antenna is reflected, the problem of main lobe splitting is solved. 3D printing technology relying on PLA (polylactic acid) granule raw materials was used to make the coaxial connector bracket and segmented parabolic surface. The reflective surface was vacuum coated (via aluminum evaporation) with low-loss aluminum. The manufacturing method is environmentally friendly and the structure was printed with 0.1 mm accuracy based on large-scale commercial applications at a low cost. The experimental results show that the reflector antenna proposed in this paper achieves a high gain of nearly 20 dBi in 57–64 GHz frequency band and ensures that the main lobe does not split.
      Citation: Electronics
      PubDate: 2019-02-11
      DOI: 10.3390/electronics8020203
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 204: Multi-Layer Problems and Solutions in
           VANETs: A Review

    • Authors: Khan, Lee
      First page: 204
      Abstract: The Dedicated Short Range Communication (DSRC) technology supports the vehicular communications through Vehicle to Vehicle (V2V) and Vehicle to Infrastructure (V2I) Communication, by operating at 5.9 GHz band (U.S. Standard). The Physical (PHY) and Medium Access Control (MAC) Layer are defined by the IEEE 802.11p, while the IEEE 1609 family of standards define the Wireless Access in Vehicular Environment (WAVE); a suite of communication and security standards in the Vehicular Area Networks (VANETs). There has been a lot of research regarding several challenges in VANETs, from spectrum utilization to multichannel operation and from routing to security issues. The aim of all is to improve the performance of the network and support scalability in VANETs; which is defined as the ability of the network to handle the addition of vehicles (nodes) without suffering noticeable degradation of performance or administrative overhead. In this paper, we aim to highlight multilayer challenges concerning the performance of the VANETs, the already proposed solutions, and the possible future work.
      Citation: Electronics
      PubDate: 2019-02-11
      DOI: 10.3390/electronics8020204
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 205: Design of A Series Resonant Converter GMAW
           Welding Machine by Using the Harmonic Current Technique for Power Transfer

    • Authors: Altanneh, Uslu, Aydemir
      First page: 205
      Abstract: This paper proposes the use of a control algorithm that can yield soft switching both at turn-on and turn-off of the inverter of series resonance converter (SRC) gas metal arc welding (GMAW) machines. The technique takes advantage of the band-pass filter characteristics of the SRC and controls the power by using switching frequencies that are subharmonics of the resonance frequency. The design and the experimental results for a 5 kW prototype system are given to prove that the algorithm can be used in GMAW systems.
      Citation: Electronics
      PubDate: 2019-02-12
      DOI: 10.3390/electronics8020205
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 206: Resource Allocation in Wireless-Powered
           Mobile Edge Computing Systems for Internet of Things Applications

    • Authors: Liu, Xu, Zhou
      First page: 206
      Abstract: Wireless devices in Internet of Things (IoT) applications, such as wireless sensors and Radio Frequency Identifications (RFIDs), are faced with challenges of heavy computation tasks and limited energy, which can be solved by the importation of mobile edge computing (MEC) and wireless power transfer (WPT) techniques. As MEC can effectively enhance computation capability, and the wireless power transfer can ensure a sustainable supply of energy, it has drawn significant research interest in IoT applications. In this paper, we will study the resource allocation problem in the wireless-powered MEC system for IoT applications with one access point (AP) and many other wireless devices, and propose a Stackelberg dynamic game model to obtain the optimal allocated resource for the nodes in the IoT environment. The AP is a wireless power source that can charge wireless devices based on wireless power transfer techniques. The AP is also integrated with a MEC server that can carry out computation tasks that offload from wireless devices. The wireless devices can use the harvested energy to execute and offload computation tasks to the AP. Based on the proposed game model, the AP and wireless devices can control their optimal transmit power for energy transfer, and computation tasks offloading to the AP, respectively. The numerical simulation results show the correctness and effectiveness of the proposed model.
      Citation: Electronics
      PubDate: 2019-02-12
      DOI: 10.3390/electronics8020206
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 207: Robust Control of Heterogeneous Vehicular
           Platoon with Non-Ideal Communication

    • Authors: Liu, Gao, He, Wang
      First page: 207
      Abstract: The application of wireless communication to platooning brings such challenges as information delay and varieties of interaction topologies. To compensate for the information delay, a state predictor based control strategy is proposed, which transmits the future information of nodes instead of current values. Based on the closed loop dynamics of platoon with state predictor and feedback controller, a decoupling strategy is presented to analysis and design the platoon control system with lower order by adopting the eigenvalue decomposition of topological matrix. A numerical method based on LMI (Linear Matrix Inequality) is provided to find the required robust performance controller. Moreover, the influence of information delay on performance is studied theoretically and it is found that the tolerable maximum delay is determined by the maximum topological eigenvalue. The effectiveness of the proposed strategy is validated by several comparative simulations under various conditions with other methods.
      Citation: Electronics
      PubDate: 2019-02-12
      DOI: 10.3390/electronics8020207
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 208: Motion Equations and Attitude Control in
           the Vertical Flight of a VTOL Bi-Rotor UAV

    • Authors: Sergio Garcia-Nieto, Jesus Velasco-Carrau, Federico Paredes-Valles, Jose Vicente Salcedo, Raul Simarro
      First page: 208
      Abstract: This paper gathers the design and implementation of the control system that allows an unmanned Flying-wing to perform a Vertical Take-Off and Landing (VTOL) maneuver using two tilting rotors (Bi-Rotor). Unmanned Aerial Vehicles (UAVs) operating in this configuration are also categorized as Hybrid UAVs due to their ability of having a dual flight envelope: hovering like a multi-rotor and cruising like a traditional fixed-wing, providing the opportunity of facing complex missions in which these two different dynamics are required. This work exhibits the Bi-Rotor nonlinear dynamics, the attitude tracking controller design and also, the results obtained through Hardware-In-the-Loop (HIL) simulation and experimental studies that ensure the controller’s efficiency in hovering operation.
      Citation: Electronics
      PubDate: 2019-02-12
      DOI: 10.3390/electronics8020208
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 209: A Novel MFDFA Algorithm and Its
           Application to Analysis of Harmonic Multifractal Features

    • Authors: Jiming Li, Xinyan Ma, Meng Zhao, Xuezhen Cheng
      First page: 209
      Abstract: A power grid harmonic signal is characterized as having both nonlinear and nonstationary features. A novel multifractal detrended fluctuation analysis (MFDFA) algorithm combined with the empirical mode decomposition (EMD) theory and template movement is proposed to overcome some shortcomings in the traditional MFDFA algorithm. The novel algorithm is used to study the multifractal feature of harmonic signals at different frequencies. Firstly, the signal is decomposed and the characteristics of wavelet transform multiresolution analysis are employed to obtain the components at different frequency bands. After this, the local fractal characteristic of the components is studied by utilizing the novel MFDFA algorithm. The experimental results show that the harmonic signals exhibit obvious multifractal characteristics and that the multifractal intensity is related to the signal frequency. Compared with the traditional MFDFA algorithm, the proposed method is more stable in curve fitting and can extract the multifractal features more accurately.
      Citation: Electronics
      PubDate: 2019-02-13
      DOI: 10.3390/electronics8020209
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 210: Design of Experiment (DOE) Analysis of
           System Level ESD Noise Coupling to High-Speed Memory Modules

    • Authors: Jawad Yousaf, Muhammad Faisal, Jinsung Youn, Wansoo Nah
      First page: 210
      Abstract: This paper presents, for the first time, a comprehensive detailed design of experiment (DOE) based system level electrostatic discharge (ESD) coupling analysis of high-speed dynamic random access (DRAM) memory modules. The sensitive traces and planes on the high-speed DRAM modules (DDR3 and DDR4) against injected ESD noise are determined through full-wave numerical simulations of the memory modules using the developed 3D model of the ESD gun. The validity of the full-wave numerical setup is confirmed through measurements, prior to the DOE analysis. Besides, current distribution analysis of DRAMs, seven different DOE configurations based on the number of installed decoupling capacitors (decaps) and their values on memory modules, are analyzed. The findings of DOE analysis suggests that DDR4 is less susceptible (70–80 % less) to the coupled ESD noise compared to DDR3. In addition, the command address (CA) nets are most sensitive in both memory modules. The utilization of the maximum possible number of decaps covering low, medium and high frequency ranges, as well as separate power and ground layers in memory stack-up design, increase the robustness and immunity of memory modules for the transient ESD event. The suggested approach offers time-saving and financial advantages to high-speed memory community, with the robust design of the memory products at the design stage before the start of the production phase.
      Citation: Electronics
      PubDate: 2019-02-13
      DOI: 10.3390/electronics8020210
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 211: Hardware RTOS: Custom Scheduler
           Implementation Based on Multiple Pipeline Registers and MIPS32

    • Authors: Ionel Zagan, Vasile Gheorghiță Găitan
      First page: 211
      Abstract: The task context switch operation, the inter-task synchronization and communication mechanisms, as well as the jitter occurred in treating aperiodic events, are crucial factors in implementing real-time operating systems (RTOS). In practice and literature, several solutions can be identified for improving the response speed and performance of real-time systems. Software implementations of RTOS-specific functions can generate significant delays, adversely affecting the deadlines required for certain applications. This paper presents an original implementation of a dedicated processor, based on multiple pipeline registers, and a hardware support for a dynamic scheduler with the following characteristics: performs unitary event management, provides access to architecture shared resources, prioritizes and executes the multiple events expected by the same task. The paper also presents a method through which interrupts are assigned to tasks. Through dedicated instructions, the integrated hardware scheduler implements tasks synchronization with multiple prioritized events, thus ensuring an efficient functioning of the processor in the context of real-time control.
      Citation: Electronics
      PubDate: 2019-02-14
      DOI: 10.3390/electronics8020211
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 212: Safety Analysis of AADL Models for Grid
           Cyber-Physical Systems via Model Checking of Stochastic Games

    • Authors: Xiaomin Wei, Yunwei Dong, Pengpeng Sun, Mingrui Xiao
      First page: 212
      Abstract: As safety-critical systems, grid cyber-physical systems (GCPSs) are required to ensure the safety of power-related systems. However, in many cases, GCPSs may be subject to uncertain and nondeterministic environmental hazards, as well as the variable quality of devices. They can cause failures and hazards in the whole system and may jeopardize system safety. Thus, it necessitates safety analysis for system safety assurance. This paper proposes an architecture-level safety analysis approach for GCPSs applying the probabilistic model-checking of stochastic games. GCPSs are modeled using Architecture Analysis and Design Language (AADL). Random errors and failures of a GCPS and nondeterministic environment behaviors are explicitly described with AADL annexes. A GCPS AADL model including the environment can be regarded as a game. To transform AADL models to stochastic multi-player games (SMGs) models, model transformation rules are proposed and the completeness and consistency of rules are proved. Property formulae are formulated for formal verification of GCPS SMG models, so that occurrence probabilities of failed states and hazards can be obtained for system-level safety analysis. Finally, a modified IEEE 9-bus system with grid elements that are power management systems is modeled and analyzed using the proposed approach.
      Citation: Electronics
      PubDate: 2019-02-14
      DOI: 10.3390/electronics8020212
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 213: 16.8/15.2 ppm/°C 81 nW High PSRR
           Dual-Output Voltage Reference for Portable Biomedical Application

    • Authors: Hongwei Yue, Xiaofei Sun, Junxin Liu, Weilin Xu, Haiou Li, Baolin Wei, Taotao Wang, Siyu Lin
      First page: 213
      Abstract: A dual-output voltage reference circuit with two reference voltages of 281 mV (Vref1) and 320.5 mV (Vref2) is presented in this paper. With a novel and precise circuit structure, the proposed circuit, operating in the subthreshold region, integrates two different output voltages into a circuit to form a dual-output voltage reference, and cascode current mirrors are used to enhance the power supply rejection ratio (PSRR). The proposed circuit was designed in a standard 0.18-µm CMOS process and has a series of attractive features: low-temperature coefficient (TC), high-PSRR, low-Line sensitivity (LS), small-chip area and low-power consumption. Monte Carlo simulations for 2000 samples showed that the output voltages 281 mV and 320.5 mV had a variation coefficient of 1.73% and 1.44%, respectively. The minimum power consumption was 84.1 nW at 0.9 V supply, proving that the circuit is suitable for portable biomedical application. The active area of the proposed voltage reference was only 0.0086 mm2.
      Citation: Electronics
      PubDate: 2019-02-15
      DOI: 10.3390/electronics8020213
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 214: A Nonisolated Three-Port DC–DC Converter
           with Continuous Input and Output Currents Based on Cuk Topology for
           PV/Fuel Cell Applications

    • Authors: Balaji Chandrasekar, Chellammal Nallaperumal, Subranshu Sekhar Dash
      First page: 214
      Abstract: A nonisolated three-port DC–DC converter based on Cuk topology (NI-TPC) to handle the renewable sources (RS) is proposed in this paper. This converter includes two unidirectional input ports accommodating both a fuel cell (FC) and photovoltaic (PV) cell; and one output port with DC load. Due to the inductors at all the ports, it claims the advantage of continuous input and output currents. Additionally, it uses less number of switches, diodes and inductors compared with conventional ‘n-1’ separate Cuk converters. Synthesis procedure for a generalized n-port DC–DC structure is explained. The derivation law based on conventional Cuk converter, operating principle, design calculation, and analysis are presented in detail, and then the analysis is validated through simulation and a 100W prototype, verifying the performance of the proposed NI-TPC converter.
      Citation: Electronics
      PubDate: 2019-02-15
      DOI: 10.3390/electronics8020214
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 215: Design of XOR Photonic Gate using Highly
           Nonlinear Fiber

    • Authors: Mohammed A. Jasim, Adel Aldalbahi
      First page: 215
      Abstract: In this paper, a comprehensive design and simulation of an all-photonic XOR logic gate is proposed. The design is based on the third-order Kerr nonlinear effect in highly nonlinear fiber, i.e., utilizing the self-phase and cross-phase modulations phenomena. This work presents the first photonic logic gate based on highly nonlinear fiber component only that achieves a data rate of 20 Gbps. Moreover, the design is based on two input binary bit sequences, narrow pulsed by a Gaussian distribution as 8-bit incoming data streams. Also, optical cross connectors with different coupling coefficients are used to generate pump and probe signals and tuneable optical band pass filters are leveraged to perform the logic gate functionalities. Remarkable performance outcomes are concluded from the eye pattern diagram and bit error rate analyzers. Simulation results show that the proposed XOR optical logic gate design is achieved at very low power penalties, low bit error rates, a significant Q-factor, and high extinction ratios as compared to existing methods.
      Citation: Electronics
      PubDate: 2019-02-15
      DOI: 10.3390/electronics8020215
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 216: Small-Signal Stability Criteria in AC
           Distribution Systems—A Review

    • Authors: Atta Ur Rahman, Irtaza Syed, Mukhtar Ullah
      First page: 216
      Abstract: AC distribution grid is prone to instability due to negative impedance and constant power nature of the load if it is dominant with power electronics-based components. There are various time-domain and frequency-domain modelling methods which use various methodologies and analytical tools. Also, there are many small-signal stability analysis (SSSA) methods and their different variants for different specific conditions and situation. This paper presents a review of SSSA methods in AC distribution grid using impedance-based models in a synchronous reference frame (SRF). By simplifying and converting the system into load and source subsystem, the impedances of both subsystems are determined by perturbation method. For a single-phase system, Hilbert transform can be used to derive the equivalent SRF model. Afterwards, the Nyquist stability criterion can be used for stability analysis.
      Citation: Electronics
      PubDate: 2019-02-15
      DOI: 10.3390/electronics8020216
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 217: A Modified Model Predictive Power Control
           for Grid-Connected T-Type Inverter with Reduced Computational Complexity

    • Authors: Van-Quang-Binh Ngo, Minh-Khai Nguyen, Tan-Tai Tran, Joon-Ho Choi, Young-Cheol Lim
      First page: 217
      Abstract: This study proposed a modified power strategy based on model predictive control for a grid-connected three-level T-type inverter. The controller utilizes the mathematical model to forecast the performance of the grid current, the balance of DC-bus capacitor voltages and switching frequency. The proposed method outlines a new technique to formulate a control objective. The control objective includes the absolute error of the inverter voltage reference and its possible values instead of the grid current error. By using the modified equivalent transformations in the cost function, the execution time was reduced 22% compared to the traditional model predictive control while maintaining the high dynamic performances of the power and low total harmonic distortion of the current. A comparative investigation showed that the proposed method obtains a high-performance control compared with the classical power control scheme with linear PI controllers and space vector modulation. The feasibility of the proposed method was verified by the simulation and experimental results.
      Citation: Electronics
      PubDate: 2019-02-15
      DOI: 10.3390/electronics8020217
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 218: An Enhanced Multi-Objective Gray Wolf
           Optimization for Virtual Machine Placement in Cloud Data Centers

    • Authors: Aisha Fatima, Nadeem Javaid, Ayesha Anjum Butt, Tanzeela Sultana, Waqar Hussain, Muhammad Bilal, Muhammad Aqeel ur Rehman Hashmi, Mariam Akbar, Manzoor Ilahi
      First page: 218
      Abstract: Cloud computing offers various services. Numerous cloud data centers are used to provide these services to the users in the whole world. A cloud data center is a house of physical machines (PMs). Millions of virtual machines (VMs) are used to minimize the utilization rate of PMs. There is a chance of unbalanced network due to the rapid growth of Internet services. An intelligent mechanism is required to efficiently balance the network. Multiple techniques are used to solve the aforementioned issues optimally. VM placement is a great challenge for cloud service providers to fulfill the user requirements. In this paper, an enhanced levy based multi-objective gray wolf optimization (LMOGWO) algorithm is proposed to solve the VM placement problem efficiently. An archive is used to store and retrieve true Pareto front. A grid mechanism is used to improve the non-dominated VMs in the archive. A mechanism is also used for the maintenance of an archive. The proposed algorithm mimics the leadership and hunting behavior of gray wolves (GWs) in multi-objective search space. The proposed algorithm was tested on nine well-known bi-objective and tri-objective benchmark functions to verify the compatibility of the work done. LMOGWO was then compared with simple multi-objective gray wolf optimization (MOGWO) and multi-objective particle swarm optimization (MOPSO). Two scenarios were considered for simulations to check the adaptivity of the proposed algorithm. The proposed LMOGWO outperformed MOGWO and MOPSO for University of Florida 1 (UF1), UF5, UF7 and UF8 for Scenario 1. However, MOGWO and MOPSO performed better than LMOGWO for UF2. For Scenario 2, LMOGWO outperformed the other two algorithms for UF5, UF8 and UF9. However, MOGWO performed well for UF2 and UF4. The results of MOPSO were also better than the proposed algorithm for UF4. Moreover, the PM utilization rate (%) was minimized by 30% with LMOGWO, 11% with MOGWO and 10% with MOPSO.
      Citation: Electronics
      PubDate: 2019-02-16
      DOI: 10.3390/electronics8020218
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 219: Weighted Neighborhood Preserving Ensemble

    • Authors: Sumet Mehta, Bi-Sheng Zhan, Xiang-Jun Shen
      First page: 219
      Abstract: Neighborhood preserving embedding (NPE) is a classical and very promising supervised dimensional reduction (DR) technique based on a linear graph, which preserves the local neighborhood relations of the data points. However, NPE uses the K nearest neighbor (KNN) criteria for constructing an adjacent graph which makes it more sensitive to neighborhood size. In this article, we propose a novel DR method called weighted neighborhood preserving ensemble embedding (WNPEE). Unlike NPE, the proposed WNPEE constructs an ensemble of adjacent graphs with the number of nearest neighbors varying. With this graph ensemble building, WNPEE can obtain the low-dimensional projections with optimal embedded graph pursuing in a joint optimization manner. WNPEE can be applied in many machine learning fields, such as object recognition, data classification, signal processing, text categorization, and various deep learning tasks. Extensive experiments on Olivetti Research Laboratory (ORL), Georgia Tech, Carnegie Mellon University-Pose and Illumination Images (CMU PIE) and Yale, four face databases demonstrate that WNPEE achieves a competitive and better recognition rate than NPE and other comparative DR methods. Additionally, the proposed WNPEE achieves much lower sensitivity to the neighborhood size parameter as compared to the traditional NPE method while preserving more of the local manifold structure of the high-dimensional data.
      Citation: Electronics
      PubDate: 2019-02-16
      DOI: 10.3390/electronics8020219
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 220: Robust Visual Compass Using Hybrid
           Features for Indoor Environments

    • Authors: Ruibin Guo, Keju Peng, Dongxiang Zhou, Yunhui Liu
      First page: 220
      Abstract: Orientation estimation is a crucial part of robotics tasks such as motion control, autonomous navigation, and 3D mapping. In this paper, we propose a robust visual-based method to estimate robots’ drift-free orientation with RGB-D cameras. First, we detect and track hybrid features (i.e., plane, line, and point) from color and depth images, which provides reliable constraints even in uncharacteristic environments with low texture or no consistent lines. Then, we construct a cost function based on these features and, by minimizing this function, we obtain the accurate rotation matrix of each captured frame with respect to its reference keyframe. Furthermore, we present a vanishing direction-estimation method to extract the Manhattan World (MW) axes; by aligning the current MW axes with the global MW axes, we refine the aforementioned rotation matrix of each keyframe and achieve drift-free orientation. Experiments on public RGB-D datasets demonstrate the robustness and accuracy of the proposed algorithm for orientation estimation. In addition, we have applied our proposed visual compass to pose estimation, and the evaluation on public sequences shows improved accuracy.
      Citation: Electronics
      PubDate: 2019-02-16
      DOI: 10.3390/electronics8020220
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 221: Nonlinear Position Stabilizing Control
           with Active Damping Injection Technique for Magnetic Levitation Systems

    • Authors: Seok-Kyoon Kim
      First page: 221
      Abstract: This proposal suggests a novel nonlinear position-stabilizing controller for magnetic levitation (MAGLEV) applications. The proposed scheme is devised by combining the active damping injection technique and disturbance observers (DOBs), considering the inherent nonlinear dynamics, as well as parameter and load variations. The convergence and performance recovery properties are obtained by analyzing the closed-loop dynamics, which is the main contribution. The numerical verification confirms a considerable closed-loop robustness improvement, compared with the cascade-type feedback-linearization controller.
      Citation: Electronics
      PubDate: 2019-02-17
      DOI: 10.3390/electronics8020221
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 222: Ultra-Short Pulsed Laser Annealing Effects
           on MoS2 Transistors with Asymmetric and Symmetric Contacts

    • Authors: Hyeokjin Kwon, Seunghun Baik, Jae Eun Jang, Jaewon Jang, Sunkook Kim, Costas P. Grigoropoulos, Hyuk-Jun Kwon
      First page: 222
      Abstract: The ultra-short pulsed laser annealing process enhances the performance of MoS2 thin film transistors (TFTs) without thermal damage on plastic substrates. However, there has been insufficient investigation into how much improvement can be brought about by the laser process. In this paper, we observed how the parameters of TFTs, i.e., mobility, subthreshold swing, Ion/Ioff ratio, and Vth, changed as the TFTs’ contacts were (1) not annealed, (2) annealed on one side, or (3) annealed on both sides. The results showed that the linear effective mobility (μeff_lin) increased from 13.14 [cm2/Vs] (not annealed) to 18.84 (one side annealed) to 24.91 (both sides annealed). Also, Ion/Ioff ratio increased from 2.27 × 10 5 (not annealed) to 3.14 × 10 5 (one side annealed) to 4.81 × 10 5   (both sides annealed), with Vth shifting to negative direction. Analyzing the main reason for the improvement through the Y function method (YFM), we found that both the contact resistance (Rc) and the channel interface resistance (Rch) improves after the pulsed laser annealings under different conditions. Moreover, the Rc enhances more dramatically than the Rch does. In conclusion, our picosecond laser annealing improves the performance of TFTs (especially, the Rc) in direct proportion to the number of annealings applied. The results will contribute to the investigation about correlations between the laser annealing process and the performance of devices.
      Citation: Electronics
      PubDate: 2019-02-17
      DOI: 10.3390/electronics8020222
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 223: Open Embedded Real-time Controllers for
           Industrial Distributed Control Systems

    • Authors: Raimarius Delgado, Jaeho Park, Byoung Wook Choi
      First page: 223
      Abstract: This paper presents design details adopting open embedded systems (OES) as real-time controllers in industrial distributed control systems. OES minimize development cost and enhance portability while addressing widely known shortcomings of their proprietary counterparts. These shortcomings include the black box method of distribution which hinders integration to more complex systems. However, OES are highly dependent on the compatibility of each software components and essential benchmarking is required to ensure that the system can satisfy hard real-time constraints. To address these issues and the notion that OES will find broader distributed control applications, we provide detailed procedures in realizing OES based on an open source real-time operating system on various low-cost open embedded platforms. Their performance was evaluated and compared in terms of periodicity and schedulability, task synchronization, and interrupt response time, which are crucial metrics to determine stability and reliability of real-time controllers. Practical implementations, including the modernization of a multi-axis industrial robot controller, are described clearly to serve as a comprehensive reference on the integration of OES in industrial distributed control systems.
      Citation: Electronics
      PubDate: 2019-02-17
      DOI: 10.3390/electronics8020223
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 224: Transferring Know-How for an Autonomous
           Camera Robotic Assistant

    • Authors: Irene Rivas-Blanco, Carlos J. Perez-del-Pulgar, Carmen López-Casado, Enrique Bauzano, Víctor F. Muñoz
      First page: 224
      Abstract: Robotic platforms are taking their place in the operating room because they provide more stability and accuracy during surgery. Although most of these platforms are teleoperated, a lot of research is currently being carried out to design collaborative platforms. The objective is to reduce the surgeon workload through the automation of secondary or auxiliary tasks, which would benefit both surgeons and patients by facilitating the surgery and reducing the operation time. One of the most important secondary tasks is the endoscopic camera guidance, whose automation would allow the surgeon to be concentrated on handling the surgical instruments. This paper proposes a novel autonomous camera guidance approach for laparoscopic surgery. It is based on learning from demonstration (LfD), which has demonstrated its feasibility to transfer knowledge from humans to robots by means of multiple expert showings. The proposed approach has been validated using an experimental surgical robotic platform to perform peg transferring, a typical task that is used to train human skills in laparoscopic surgery. The results show that camera guidance can be easily trained by a surgeon for a particular task. Later, it can be autonomously reproduced in a similar way to one carried out by a human. Therefore, the results demonstrate that the use of learning from demonstration is a suitable method to perform autonomous camera guidance in collaborative surgical robotic platforms.
      Citation: Electronics
      PubDate: 2019-02-18
      DOI: 10.3390/electronics8020224
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 225: Evaluation of Multi-Beam Massive MIMO
           Considering MAC Layer Using IEEE802.11ac and FDD-LTE

    • Authors: Fumiya Muramatsu, Kentaro Nishimori, Ryotaro Taniguchi, Takefumi Hiraguri, Tsutomu Mitsui
      First page: 225
      Abstract: Massive multiple-input multiple-output (MIMO) transmission has attracted attention as a key technology for use in fifth-generation mobile communication systems. Multi-beam massive MIMO systems that apply beam selection in analog components and blind algorithms in digital components to eliminate the requirement for channel state information have been proposed as a method for reducing overhead. In this study, we developed an adaptive modulation scheme for implementing multi-beam massive MIMO and used computer simulation to compare it with digital and analog–digital hybrid beam-forming methods. The effectiveness of the proposed system was verified in a medium access control layer based on the IEEE802.11ac and frequency division duplex-LTE representative wireless communication standards.
      Citation: Electronics
      PubDate: 2019-02-18
      DOI: 10.3390/electronics8020225
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 226: LS-Solar-PV System Impact on Line

    • Authors: Qais Alsafasfeh, Omar A. Saraereh, Imran Khan, Sunghwan Kim
      First page: 226
      Abstract: Large-scale photovoltaic power station access to the grid will profoundly change the fault current characteristics of the power station’s outgoing lines. This change results in adaptive problems in traditional protection phase selection components, which may cause incorrect actions in reclosing, protection ranging, and distance protection. Based on the fault current characteristics of the large-scale photovoltaic power station transmission line, this paper analyzes the adaptability of the phase current difference mutation and the sequence component phase selection component in protecting the Photovoltaic (PV) power plant side of the transmission line. Based on the fault current analytical formula, the phase relationship between the phase current difference and the current sequence component under different control targets, such as suppressing negative sequence current, suppressing the active power fluctuation, and suppressing the reactive power fluctuation, is derived. The operational performances of the phase–phase current difference of the abrupt phase selection component and the sequence component phase selection component of the power station side are degraded, which may cause incorrect operation of the phase selection component. Based on the actual engineering parameters of a PV power plant, a simulation model was built in Power System Computer Aided Design (PSCAD) to verify the correctness of the theoretical analysis.
      Citation: Electronics
      PubDate: 2019-02-18
      DOI: 10.3390/electronics8020226
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 227: Voltage Multiplier Cell-Based
           Quasi-Switched Boost Inverter with Low Input Current Ripple

    • Authors: Minh-Khai Nguyen, Youn-Ok Choi
      First page: 227
      Abstract: A novel single-phase single-stage voltage multiplier cell-based quasi-switched boost inverter (VMC-qSBI) is proposed in this paper. By adding the voltage multiplier cell to the qSBI, the proposed VMC-qSBI has the following merits; a decreased voltage stress on an additional switch, a high voltage gain, a continuous input current, shoot through immunity, and a high modulation index. A new pulse-width modulation (PWM) control strategy is presented for the proposed inverter to reduce the input current ripple. To improve the voltage gain of the proposed inverter, an extension is addressed by adding the VMCs. The operating principle, steady-state analysis, and impedance parameter design guideline of the proposed inverter are presented. A comparison between the proposed inverter and other impedance source-based high-voltage gain inverters is shown. Simulation and experimental results are provided to confirm the theoretical analysis.
      Citation: Electronics
      PubDate: 2019-02-18
      DOI: 10.3390/electronics8020227
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 228: DSCBlocks: An Open-Source Platform for
           Learning Embedded Systems Based on Algorithm Visualizations and Digital
           Signal Controllers

    • Authors: Jonathan Álvarez Ariza
      First page: 228
      Abstract: DSCBlocks is an open-source platform in hardware and software developed in JavaFX, which is focused on learning embedded systems through Digital Signal Controllers (DSCs). These devices are employed in industrial and educational sectors due to their robustness, number of peripherals, processing speed, scalability and versatility. The platform uses graphical blocks designed in Google’s tool Blockly that can be used to build different Algorithm Visualizations (AVs). Afterwards, the algorithms are converted in real-time to C language, according to the specifications of the compiler for the DSCs (XC16) and they can be downloaded in one of the two models of development board for the dsPIC 33FJ128GP804 and dsPIC 33FJ128MC802. The main aim of the platform is to provide a flexible environment, drawing on the educational advantages of the AVs with different aspects concerning the embedded systems, such as declaration of variables and functions, configuration of ports and peripherals, handling of Real-Time Operating System (RTOS), interrupts, among others, that are employed in several fields such as robotics, control, instrumentation, etc. In addition, some experiments that were designed in the platform are presented in the manuscript. The educational methodology and the assessment provided by the students (n = 30) suggest that the platform is suitable and reliable to learn concepts relating to embedded systems.
      Citation: Electronics
      PubDate: 2019-02-18
      DOI: 10.3390/electronics8020228
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 229: Pansharpening with a Gradient Domain GIF
           Based on NSST

    • Authors: Jiao Jiao, Lingda Wu
      First page: 229
      Abstract: In order to improve the fusion quality of multispectral (MS) and panchromatic (PAN) images, a pansharpening method with a gradient domain guided image filter (GIF) that is based on non-subsampled shearlet transform (NSST) is proposed. First, multi-scale decomposition of MS and PAN images is performed by NSST. Second, different fusion rules are designed for high- and low-frequency coefficients. A fusion rule that is based on morphological filter-based intensity modulation (MFIM) technology is proposed for the low-frequency coefficients, and the edge refinement is carried out based on a gradient domain GIF to obtain the fused low-frequency coefficients. For the high-frequency coefficients, a fusion rule based on an improved pulse coupled neural network (PCNN) is adopted. The gradient domain GIF optimizes the firing map of the PCNN model, and then the fusion decision map is calculated to guide the fusion of the high-frequency coefficients. Finally, the fused high- and low-frequency coefficients are reconstructed with inverse NSST to obtain the fusion image. The proposed method was tested using the WorldView-2 and QuickBird data sets; the subjective visual effects and objective evaluation demonstrate that the proposed method is superior to the state-of-the-art pansharpening methods, and it can efficiently improve the spatial quality and spectral maintenance.
      Citation: Electronics
      PubDate: 2019-02-18
      DOI: 10.3390/electronics8020229
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 230: QoS-Based DWBA Algorithm for NG-EPON

    • Authors: Ammar Rafiq, Muhammad Faisal Hayat
      First page: 230
      Abstract: The next-generation Ethernet passive optical network (NG-EPON) is basically classified into two architectures on the basis of the wavelength sharing by the optical network units (ONUs). The single scheduling domain (SSD) and multi-scheduling domain (MSD) EPON are the two different design architectures for NG-EPON. A vital task in NG-EPON is to design dynamic wavelength bandwidth allocation (DWBA) algorithms that can meet the future demands of the network subscribers. A number of DWBA algorithms have been designed for time and wavelength division multiplex (TWDM) EPON. The existing DWBA algorithms for TWDM-EPON could be used in MSD-EPON by making necessary parametric changes. The design and implementation of new DWBA algorithms for MSD-EPON are still required specifically. In this paper, we have proposed a quality of service (QoS)-based DWBA algorithm for NG-EPON. We have comparatively analyzed our proposed DWBA with the existing algorithms like earlier finished time (EFT), weighted bipartite matching (WBM), and earlier finished time with void filling (EFT-VF). The results show that our proposed DWBA algorithm performs better as compared to EFT, WBM, and EFT-VF on the basis of average packet delay and average completion time for NG-EPON.
      Citation: Electronics
      PubDate: 2019-02-18
      DOI: 10.3390/electronics8020230
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 231: Online Tuning of a PID Controller with a
           Fuzzy Reinforcement Learning MAS for Flow Rate Control of a Desalination

    • Authors: Kofinas, Dounis
      First page: 231
      Abstract: This paper proposes a hybrid Zeigler-Nichols (Z-N) fuzzy reinforcement learning MAS (Multi-Agent System) approach for online tuning of a Proportional Integral Derivative (PID) controller in order to control the flow rate of a desalination unit. The PID gains are set by the Z-N method and then are adapted online through the fuzzy Q-learning MAS. The fuzzy Q-learning is introduced in each agent in order to confront with the continuous state-action space. The global state of the MAS is defined by the value of the error and the derivative of error. The MAS consists of three agents and the output signal of each agent defines the percentage change of each gain. The increment or the reduction of each gain can be in the range of 0% to 100% of its initial value. The simulation results highlight the performance of the suggested hybrid control strategy through comparison with the conventional PID controller tuned by Z-N.
      Citation: Electronics
      PubDate: 2019-02-18
      DOI: 10.3390/electronics8020231
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 232: Design of a Low-Cost PV Emulator Applied
           for PVECS

    • Authors: Intissar Moussa, Adel Khedher, Adel Bouallegue
      First page: 232
      Abstract: Applied tests on a real photovoltaic panel for a consolidated analysis require complex experiment setup and permanent availability of climatic conditions. This method is ineffective and can damage the PV system. As a result, PV emulators are highly requested in solar energy conversion and generation research, which rests essentially on a maximum power point tracking control algorithm (MPPT) and an adapting power stage as the DC-DC converter and PV inverter. The PV emulator guarantees a controllable light source environment to act as a real PV system in the laboratory. This paper deals with the study and development of an experimental PV emulator based on logarithmic approximation of the ideal single diode model (ISDM), which is implemented using analog electronic components. Mainly, the PV model, the controller, and the power stages, forming the PV emulator, are described. This simple, low-cost, and efficient device is considered as a nonlinear power supply template replacing the real PV system for any operating point irrespective of the environmental condition changes. The emulated current-voltage and power-voltage curves are validated via resistive load and batteries. Then, the performance of the proposed PV emulator is evaluated by its ability to recharge properly two 12V 7 Ah batteries.
      Citation: Electronics
      PubDate: 2019-02-19
      DOI: 10.3390/electronics8020232
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 233: Camera-Based Blind Spot Detection with a
           General Purpose Lightweight Neural Network

    • Authors: Yiming Zhao, Lin Bai, Yecheng Lyu, Xinming Huang
      First page: 233
      Abstract: Blind spot detection is an important feature of Advanced Driver Assistance Systems (ADAS). In this paper, we provide a camera-based deep learning method that accurately detects other vehicles in the blind spot, replacing the traditional higher cost solution using radars. The recent breakthrough of deep learning algorithms shows extraordinary performance when applied to many computer vision tasks. Many new convolutional neural network (CNN) structures have been proposed and most of the networks are very deep in order to achieve the state-of-art performance when evaluated with benchmarks. However, blind spot detection, as a real-time embedded system application, requires high speed processing and low computational complexity. Hereby, we propose a novel method that transfers blind spot detection to an image classification task. Subsequently, a series of experiments are conducted to design an efficient neural network by comparing some of the latest deep learning models. Furthermore, we create a dataset with more than 10,000 labeled images using the blind spot view camera mounted on a test vehicle. Finally, we train the proposed deep learning model and evaluate its performance on the dataset.
      Citation: Electronics
      PubDate: 2019-02-19
      DOI: 10.3390/electronics8020233
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 234: Simulation Model for Blockchain Systems
           Using Queuing Theory

    • Authors: Raheel Ahmed Memon, Jian Ping Li, Junaid Ahmed
      First page: 234
      Abstract: In recent years, blockchains have obtained so much attention from researchers, engineers, and institutions; and the implementation of blockchains has started to revive a large number of applications ranging from e-finance, e-healthcare, smart home, Internet of Things, social security, logistics and so forth. In the literature on blockchains, it is found that most articles focused on their engineering implementation, while little attention has been devoted to the exploration of theoretical aspects of the system; however, the existing work is limited to model the mining process only. In this paper, a queuing theory-based model is proposed for understanding the working and theoretical aspects of the blockchain. We validate our proposed model using the actual statistics of two popular cryptocurrencies, Bitcoin and Ethereum, by running simulations for two months of transactions. The obtained performance measures parameters such as the Number of Transactions per block, Mining Time of Each Block, System Throughput, Memorypool count, Waiting Time in Memorypool, Number of Unconfirmed Transactions in the Whole System, Total Number of Transactions, and Number of Generated Blocks; these values are compared with actual statistics. It was found that the results gained from our proposed model are in good agreement with actual statistics. Although the simulation in this paper presents the modeling of blockchain-based cryptocurrencies only, the proposed model can be used to represent a wide range of blockchain-based systems.
      Citation: Electronics
      PubDate: 2019-02-19
      DOI: 10.3390/electronics8020234
      Issue No: Vol. 8, No. 2 (2019)
  • Electronics, Vol. 8, Pages 235: Performance Analysis of Single-Step
           Localization Method Based on Matrix Eigen-Perturbation Theory with System

    • Authors: Qin, Ba, Wang
      First page: 235
      Abstract: Direct position determination (DPD) is a novel technique in passive localization field recently, receiving superior localization performance compared with the conventional two-step method. The DPD estimator using Doppler shifts is first proposed by Weiss, but it is not suitable for antenna arrays. Additionally, the performance analysis of this method with system errors is absent. This study discusses the single-step localization problem based on moving arrays and exhibits the performance analysis via matrix eigen-perturbation theory with system errors. First, the DPD method using angle of arrival and Doppler shifts is introduced. Then, by adding the eigenvalue perturbations to the estimated Hermitian matrix, the asymptotic linear formulation of localization errors is derived. Consequently, the mean square error of the DPD method is available. Finally, Cramér–Rao bound without system errors is presented, providing a benchmark for the best localization precision and revealing the influence of system errors on the localization precision. Simulation results demonstrate the theoretical analysis in this study.
      Citation: Electronics
      PubDate: 2019-02-19
      DOI: 10.3390/electronics8020235
      Issue No: Vol. 8, No. 2 (2019)
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