Previous Issue
Volume 8, August

Table of Contents

Electronics, Volume 8, Issue 9 (September 2019)

  • Issues are regarded as officially published after their release is announced to the table of contents alert mailing list.
  • You may sign up for e-mail alerts to receive table of contents of newly released issues.
  • PDF is the official format for papers published in both, html and pdf forms. To view the papers in pdf format, click on the "PDF Full-text" link, and use the free Adobe Readerexternal link to open them.
Order results
Result details
Select all
Export citation of selected articles as:
Open AccessFeature PaperReview
The Emerging Energy Internet: Architecture, Benefits, Challenges, and Future Prospects
Electronics 2019, 8(9), 1037; https://doi.org/10.3390/electronics8091037 (registering DOI) - 15 Sep 2019
Abstract
Energy Internet is a concept proposed to harness, control, and manage energy resources effectively, with the help of information and communication technology. It improves a reliability of the system, and provides an increased utilization of energy resources by integrating the smart grid with [...] Read more.
Energy Internet is a concept proposed to harness, control, and manage energy resources effectively, with the help of information and communication technology. It improves a reliability of the system, and provides an increased utilization of energy resources by integrating the smart grid with the Internet. A scalable and reliable information and communication architecture is a crucial factor for both the operation and management of the energy Internet. The routing or managing of electrical energy is performed through an energy router (ER), synonymous with a communication router, which routes data packets instead of energy packets. In this paper, a holistic review of the energy Internet evolution in terms of the architecture, types of ERs, and the benefits and challenges of its implementation is presented. An exhaustive summary of the designs and architectures of the different types of ERs is also presented in this paper. The benefits of the energy Internet, along with the challenges of its implementation on a large-scale distributed architecture with the inclusion of renewable energy resources, is discussed. Finally, future prospects for the energy Internet for achieving guaranteed reliability and security is presented. Full article
(This article belongs to the Special Issue Photovoltaic Systems for Sustainable Energy)
Show Figures

Figure 1

Open AccessFeature PaperArticle
A Low-Cost and Compact Three-Dimensional Microwave Holographic Imaging System
Electronics 2019, 8(9), 1036; https://doi.org/10.3390/electronics8091036 (registering DOI) - 15 Sep 2019
Abstract
With the significant growth in the use of non-metallic composite materials, the demands for new and robust non-destructive testing methodologies is high. Microwave imaging has attracted a lot of attention recently for such applications. This is in addition to the biomedical imaging applications [...] Read more.
With the significant growth in the use of non-metallic composite materials, the demands for new and robust non-destructive testing methodologies is high. Microwave imaging has attracted a lot of attention recently for such applications. This is in addition to the biomedical imaging applications of microwave that are also being pursued actively. Among these efforts, in this paper, we propose a compact and cost-effective three-dimensional microwave imaging system based on a fast and robust holographic technique. For this purpose, we employ narrow-band microwave data, instead of wideband data used in previous three-dimensional cylindrical holographic imaging systems. Three-dimensional imaging is accomplished by using an array of receiver antennas surrounding the object and scanning that along with a transmitter antenna over a cylindrical aperture. To achieve low cost and compact size, we employ off-the-shelf components to build a data acquisition system replacing the costly and bulky vector network analyzers. The simulation and experimental results demonstrate the satisfactory performance of the proposed imaging system. We also show the effect of number of frequencies and size of the objects on the quality of reconstructed images. Full article
(This article belongs to the Special Issue Applications of Electromagnetic Waves)
Show Figures

Figure 1

Open AccessArticle
Design and Implementation of an Arduino-Based Plug-and-Play Acquisition System for Seismic Noise Measurements
Electronics 2019, 8(9), 1035; https://doi.org/10.3390/electronics8091035 (registering DOI) - 15 Sep 2019
Abstract
The analysis of seismic noise provides a reliable estimation of the soil properties, which supposes the starting point for the assessment of the seismic hazard. The horizontal-to-vertical spectral ratio technique calculates the resonant frequency of the soil just by using a single three-component [...] Read more.
The analysis of seismic noise provides a reliable estimation of the soil properties, which supposes the starting point for the assessment of the seismic hazard. The horizontal-to-vertical spectral ratio technique calculates the resonant frequency of the soil just by using a single three-component sensor. Array measurements require at least several vertical sensors registering simultaneously and their analysis provides an estimation of the surface waves dispersion curve. Although these methods are relatively cheaper than other geotechnical techniques, the cost of the sensors and the multi-channel data acquisition system means that small research groups cannot afford this kind of equipment. In this work, two prototypes for registering seismic noise have been developed and implemented: a three-channel acquisition system, optimized for working with three-component sensors; and a twelve-channel acquisition system, prepared for working simultaneously with twelve vertical geophones. Both prototypes are characterized by being open-hardware, open-software, easy to implement, and low-cost. The main aim is to provide a data acquisition system that can be reproduced and applied by any research group. Both developed prototypes have been tested and compared with other commercial equipment, showing their suitability to register seismic noise and to estimate the soil characteristics. Full article
(This article belongs to the Section Circuit and Signal Processing)
Show Figures

Figure 1

Open AccessArticle
Robust Current Predictive Control-Based Equivalent Input Disturbance Approach for PMSM Drive
Electronics 2019, 8(9), 1034; https://doi.org/10.3390/electronics8091034 (registering DOI) - 15 Sep 2019
Abstract
The implementation and experimental validation of current control strategy based on predictive control and equivalent input disturbance approach is discussed for permanent magnet synchronous motor (PMSM) control system in the paper. First, to realize the current decoupling control, the deadbeat predictive current control [...] Read more.
The implementation and experimental validation of current control strategy based on predictive control and equivalent input disturbance approach is discussed for permanent magnet synchronous motor (PMSM) control system in the paper. First, to realize the current decoupling control, the deadbeat predictive current control technique is adopted in the current loop of PMSM. Indeed, it is well known that the traditional deadbeat current control cannot completely reject the disturbance and realize the zero error current tracking control. Then, according to the model uncertainties and the parameter variations in the motor, an equivalent input disturbance approach is introduced to estimate the lump disturbance in the system, which will be used in the feed-forward compensation. Thus, a compound current controller is designed, and the proposed algorithm reduces the tracking error caused by the disturbance; the robustness of the drive system is improved effectively. Finally, simulation and experiment are accomplished on the control prototype, and the results show the effectiveness of the proposed current control algorithm. Full article
(This article belongs to the Special Issue Advanced Control Systems for Electric Drives)
Show Figures

Figure 1

Open AccessArticle
An Efficient and Low-Power Design of the SM3 Hash Algorithm for IoT
Electronics 2019, 8(9), 1033; https://doi.org/10.3390/electronics8091033 (registering DOI) - 14 Sep 2019
Viewed by 136
Abstract
The Internet-of-Things (IoT) has a security problem that has become increasingly significant. New architecture of SM3 which can be implemented in loT devices is proposed in this paper. The software/hardware co-design approach is put forward to implement the new architecture to achieve high [...] Read more.
The Internet-of-Things (IoT) has a security problem that has become increasingly significant. New architecture of SM3 which can be implemented in loT devices is proposed in this paper. The software/hardware co-design approach is put forward to implement the new architecture to achieve high performance and low costs. To facilitate software/hardware co-design, an AHB-SM3 interface controller (AHB-SIC) is designed as an AHB slave interface IP to exchange data with the embedded CPU. Task scheduling and hardware resource optimization techniques are adopted in the design of expansion modules. The task scheduling and critical path optimization techniques are utilized in the compression module design. The proposed architecture is implemented with ASIC using SMIC 130 nm technology. For the purpose of comparison, the proposed architecture is also implemented on Virtex 7 FPGA with a 36 MHz system clock. Compared with the standard implementation of SM3, the proposed architecture saves the number of registers for approximately 3.11 times, and 263 Mbps throughput is achieved under the 36 MHz clock. This design signifies an excellent trade-off between performance and the hardware area. Thus, the design accommodates the resource-limited IoT security devices very well. The proposed architecture is applied to an intelligent security gateway device. Full article
(This article belongs to the Section Circuit and Signal Processing)
Open AccessArticle
Layer Selection in Progressive Transmission of Motion-Compensated JPEG2000 Video
Electronics 2019, 8(9), 1032; https://doi.org/10.3390/electronics8091032 (registering DOI) - 13 Sep 2019
Viewed by 131
Abstract
MCJ2K (Motion-Compensated JPEG2000) is a video codec based on MCTF (Motion- Compensated Temporal Filtering) and J2K (JPEG2000). MCTF analyzes a sequence of images, generating a collection of temporal sub-bands, which are compressed with J2K. The R/D (Rate-Distortion) performance in MCJ2K is better than [...] Read more.
MCJ2K (Motion-Compensated JPEG2000) is a video codec based on MCTF (Motion- Compensated Temporal Filtering) and J2K (JPEG2000). MCTF analyzes a sequence of images, generating a collection of temporal sub-bands, which are compressed with J2K. The R/D (Rate-Distortion) performance in MCJ2K is better than the MJ2K (Motion JPEG2000) extension, especially if there is a high level of temporal redundancy. MCJ2K codestreams can be served by standard JPIP (J2K Interactive Protocol) servers, thanks to the use of only J2K standard file formats. In bandwidth-constrained scenarios, an important issue in MCJ2K is determining the amount of data of each temporal sub-band that must be transmitted to maximize the quality of the reconstructions at the client side. To solve this problem, we have proposed two rate-allocation algorithms which provide reconstructions that are progressive in quality. The first, OSLA (Optimized Sub-band Layers Allocation), determines the best progression of quality layers, but is computationally expensive. The second, ESLA (Estimated-Slope sub-band Layers Allocation), is sub-optimal in most cases, but much faster and more convenient for real-time streaming scenarios. An experimental comparison shows that even when a straightforward motion compensation scheme is used, the R/D performance of MCJ2K competitive is compared not only to MJ2K, but also with respect to other standard scalable video codecs. Full article
Show Figures

Figure 1

Open AccessFeature PaperArticle
High-Density EEG Signal Processing Based on Active-Source Reconstruction for Brain Network Analysis in Alzheimer’s Disease
Electronics 2019, 8(9), 1031; https://doi.org/10.3390/electronics8091031 (registering DOI) - 13 Sep 2019
Viewed by 120
Abstract
Alzheimer’s Disease (AD) is a neurological disorder characterized by a progressive deterioration of brain functions that affects, above all, older adults. It can be difficult to make an early diagnosis because its first symptoms are often associated with normal aging. Electroencephalography (EEG) can [...] Read more.
Alzheimer’s Disease (AD) is a neurological disorder characterized by a progressive deterioration of brain functions that affects, above all, older adults. It can be difficult to make an early diagnosis because its first symptoms are often associated with normal aging. Electroencephalography (EEG) can be used for evaluating the loss of brain functional connectivity in AD patients. The purpose of this paper is to study the brain network parameters through the estimation of Lagged Linear Connectivity (LLC), computed by eLORETA software, applied to High-Density EEG (HD-EEG) for 84 regions of interest (ROIs). The analysis involved three groups of subjects: 10 controls (CNT), 21 Mild Cognitive Impairment patients (MCI) and 9 AD patients. In particular, the purpose is to compare the results obtained using a 256-channel EEG, the corresponding 10–10 system 64-channel EEG and the corresponding 10–20 system 18-channel EEG, both of which are extracted from the 256-electrode configuration. The computation of the Characteristic Path Length, the Clustering Coefficient, and the Connection Density from HD-EEG configuration reveals a weakening of small-world properties of MCI and AD patients in comparison to healthy subjects. On the contrary, the variation of the network parameters was not detected correctly when we employed the standard 10–20 configuration. Only the results from HD-EEG are consistent with the expected behavior of the AD brain network. Full article
(This article belongs to the Special Issue Multidimensional Digital Signal Processing)
Show Figures

Figure 1

Open AccessArticle
Design and Characterization of a Microwave Planar Sensor for Dielectric Assessment of Vegetable Oils
Electronics 2019, 8(9), 1030; https://doi.org/10.3390/electronics8091030 (registering DOI) - 13 Sep 2019
Viewed by 113
Abstract
We report on the numerical simulations and experimental validation of a microwave planar sensor based on two coupled rings operating in the 4–6 GHz range. The fabricated sensor is used to characterize the dielectric permittivity of vegetable oils. We optimized the geometrical parameters [...] Read more.
We report on the numerical simulations and experimental validation of a microwave planar sensor based on two coupled rings operating in the 4–6 GHz range. The fabricated sensor is used to characterize the dielectric permittivity of vegetable oils. We optimized the geometrical parameters in order to improve the overlap between the oil samples under study and the electric field. The experimental results showed an excellent match with the simulation results. The fabricated sensor allowed to retrieve the oil permittivity with a sensitivity of about 35 MHz per permittivity unit in the frequency range of interest. This paves the way to the realization of compact and sensitive sensors for a wide plethora of fields ranging from industry and food to chemistry and biology. Full article
(This article belongs to the Section Microwave and Wireless Communications)
Show Figures

Graphical abstract

Open AccessArticle
A Fractional-Order Element (FOE)-Based Approach to Wireless Power Transmission for Frequency Reduction and Output Power Quality Improvement
Electronics 2019, 8(9), 1029; https://doi.org/10.3390/electronics8091029 (registering DOI) - 13 Sep 2019
Viewed by 99
Abstract
A wireless power transmission (WPT) requires high switching frequency to achieve energy transmission; however, existing switching devices cannot satisfy the requirements of high-frequency switching, and the efficiency of current WPT is too low. Compared with the traditional power inductors and capacitors, fractional-order elements [...] Read more.
A wireless power transmission (WPT) requires high switching frequency to achieve energy transmission; however, existing switching devices cannot satisfy the requirements of high-frequency switching, and the efficiency of current WPT is too low. Compared with the traditional power inductors and capacitors, fractional-order elements (FOEs) in WPT can realize necessary functions though requiring a lower switching frequency, which leads to a more favorable high-frequency switching performance with a higher efficiency. In this study, a generalized fractional-order WPT (FO-WPT) is established, followed by a comprehensive analysis on its WPT performance and power efficiency. Through extensive simulations of typical FO wireless power domino-resonators (FO-WPDRS), the functionality of the proposed FO-WPT for medium and long-range WPT is demonstrated. The numerical results show that the proposed FOE-based WPT solution has a higher power efficiency and lower switching frequency than conventional methods. Full article
(This article belongs to the Special Issue Power Converters in Power Electronics)
Show Figures

Figure 1

Open AccessArticle
Micro-Motion Feature Extraction of a Rotating Target Based on Interrupted Transmitting and Receiving Pulse Signal in an Anechoic Chamber
Electronics 2019, 8(9), 1028; https://doi.org/10.3390/electronics8091028 (registering DOI) - 13 Sep 2019
Viewed by 111
Abstract
The pulse signal is widely used in micro-motion feature extraction of rapidly rotating targets as its pulse repetition frequency (PRF) can be high. However, when the pulse signal is implemented in a range-limited anechoic chamber for micro-motion feature extraction, the transmitted and reflected [...] Read more.
The pulse signal is widely used in micro-motion feature extraction of rapidly rotating targets as its pulse repetition frequency (PRF) can be high. However, when the pulse signal is implemented in a range-limited anechoic chamber for micro-motion feature extraction, the transmitted and reflected pulse signals may be coupled at the receiver. To solve this problem, the interrupted transmitting and receiving (ITR) method is applied to transmit the pulse signal with hundreds of sub-pulses. The target echo can be received when the sub-pulse is not transmitted. Hence, it avoids the coupling effect of transmitted signals and echoes. Then, the whole process of micro-motion feature extraction for rotating target is proposed based on the ITR method. At last, the simulations and experiments verify that the rotating target micro-Doppler can be extracted by the ITR pulse signal. Full article
Show Figures

Figure 1

Open AccessArticle
Bidirectional Information Transmission in SWIPT System with Single Controlled Chopper Receiver
Electronics 2019, 8(9), 1027; https://doi.org/10.3390/electronics8091027 - 12 Sep 2019
Viewed by 166
Abstract
The wireless power transfer (WPT) technology has the advantages of convenience, safety and reliability due to its non-metal contact power supply and has a broad application prospect in many occasions. In practical applications, the information communication between the primary and secondary side is [...] Read more.
The wireless power transfer (WPT) technology has the advantages of convenience, safety and reliability due to its non-metal contact power supply and has a broad application prospect in many occasions. In practical applications, the information communication between the primary and secondary side is necessary for output voltage control, load detection, condition monitoring and other functions, which makes the WPT system more intelligent and convenient. A simultaneous wireless information and power transfer (SWIPT) system with controlled chopper circuit receiver is proposed in this paper. The load voltage remains constant by adjusting the pulse width of the secondary controlled device through feedback control. The information bidirectional transmission methods and two modes are proposed, considering different application scenarios. Simulation and experiment results validate the proposed topology and the method of information bidirectional transmission. Full article
(This article belongs to the Section Power Electronics)
Open AccessArticle
Research on In-Vehicle Key Management System under Upcoming Vehicle Network Architecture
Electronics 2019, 8(9), 1026; https://doi.org/10.3390/electronics8091026 - 12 Sep 2019
Viewed by 170
Abstract
The intelligentization and connectedness of vehicles make vehicle cybersecurity an important research topic. In-vehicle key management is a critical function in vehicle cybersecurity countermeasures. After describing previous research on vehicle key management and the development trend of vehicle network architecture, a key management [...] Read more.
The intelligentization and connectedness of vehicles make vehicle cybersecurity an important research topic. In-vehicle key management is a critical function in vehicle cybersecurity countermeasures. After describing previous research on vehicle key management and the development trend of vehicle network architecture, a key management scheme for in-vehicle multi-layer electronic control units (ECUs) is proposed. The scheme is based on authenticated key exchange protocol 2 (AKEP2) and on-the-air (OTA) technology. Then, the key storage and trusted key usage based on secure hardware are analyzed and studied. Moreover, the AES Counter with CBC-MAC (AES-CCM) algorithm, which uses fewer keys, is introduced to in-vehicle secure communication. The simulation analysis for the proposed OTA-based key update protocol verifies the protocol’s security. The validity of the hardware-based trusted key usage environment and the feasibility of the AES-CCM algorithm for the CAN FD bus are proven with corresponding experiments. Full article
(This article belongs to the Section Electrical and Autonomous Vehicles)
Open AccessArticle
Design and Implementation Procedure for an Advanced Driver Assistance System Based on an Open Source AUTOSAR
Electronics 2019, 8(9), 1025; https://doi.org/10.3390/electronics8091025 - 12 Sep 2019
Viewed by 152
Abstract
In this paper, we present the detailed design and implementation procedures for an advanced driver assistance system (ADAS) based on an open source automotive open system architecture (AUTOSAR). Due to the increasing software complexity of ADAS, portability, component interoperability, and maintenance are becoming [...] Read more.
In this paper, we present the detailed design and implementation procedures for an advanced driver assistance system (ADAS) based on an open source automotive open system architecture (AUTOSAR). Due to the increasing software complexity of ADAS, portability, component interoperability, and maintenance are becoming essential development factors. AUTOSAR satisfies these demands by defining system architecture standards. Although commercial distributions of AUTOSAR are well established, accessibility is a huge concern as they come with very expensive licensing fees. Open source AUTOSAR addresses this issue and can also minimize the overall cost of development. However, the development procedure has not been well established and could be difficult for engineers. The contribution of this paper is divided into two main parts: First, we provide the complete details on developing a collision warning system using an open source AUTOSAR. This includes the simplified basic concepts of AUTOSAR, which we have organized for easier understanding. Also, we present an improvement of the existing AUTOSAR development methodology focusing on defining the underlying tools at each development stage with clarity. Second, as the performance of open source software has not been proven and requires benchmarking to ensure the stability of the system, we propose various evaluation methods measuring the real-time performance of tasks and the overall latency of the communication stack. These performance metrics are relevant to confirm whether the entire system has deterministic behavior and responsiveness. The evaluation results can help developers to improve the overall safety of the vehicular system. Experiments are conducted on an AUTOSAR evaluation kit integrated with our self-developed collision warning system. The procedures and evaluation methods are applicable not only on detecting obstacles but other variants of ADAS and are very useful in integrating open source AUTOSAR to various vehicular applications. Full article
(This article belongs to the Special Issue Autonomous Vehicles Technology)
Open AccessArticle
Preceding Vehicle Detection Using Faster R-CNN Based on Speed Classification Random Anchor and Q-Square Penalty Coefficient
Electronics 2019, 8(9), 1024; https://doi.org/10.3390/electronics8091024 - 12 Sep 2019
Viewed by 129
Abstract
At present, preceding vehicle detection remains a challenging problem for autonomous vehicle technologies. In recent years, deep learning has been shown to be successful for vehicle detection, such as the faster region with a convolutional neural network (Faster R-CNN). However, when the host [...] Read more.
At present, preceding vehicle detection remains a challenging problem for autonomous vehicle technologies. In recent years, deep learning has been shown to be successful for vehicle detection, such as the faster region with a convolutional neural network (Faster R-CNN). However, when the host vehicle speed increases or there is an occlusion in front, the performance of the Faster R-CNN algorithm usually degrades. To obtain better performance on preceding vehicle detection when the speed of the host vehicle changes, a speed classification random anchor (SCRA) method is proposed. The reasons for degraded detection accuracy when the host vehicle speed increases are analyzed, and the factor of vehicle speed is introduced to redesign the anchors. Redesigned anchors can adapt to changes of the preceding vehicle size rule when the host vehicle speed increases. Furthermore, to achieve better performance on occluded vehicles, a Q-square penalty coefficient (Q-SPC) method is proposed to optimize the Faster R-CNN algorithm. The experimental validation results show that compared with the Faster R-CNN algorithm, the SCRA and Q-SPC methods have certain significance for improving preceding vehicle detection accuracy. Full article
(This article belongs to the Special Issue Autonomous Vehicles Technology)
Open AccessArticle
A Resource Oriented Route Selection Framework Using Contextual Information Based on Fuzzy Logic
Electronics 2019, 8(9), 1023; https://doi.org/10.3390/electronics8091023 - 12 Sep 2019
Viewed by 126
Abstract
Internet of Things (IoT) is expected to have a significant impact on city’s service provisioning and make a smart city more accessible and pragmatic since the deployment of heterogeneous smart devices in each infrastructure of cities is increasing. So far, the IPv6 routing [...] Read more.
Internet of Things (IoT) is expected to have a significant impact on city’s service provisioning and make a smart city more accessible and pragmatic since the deployment of heterogeneous smart devices in each infrastructure of cities is increasing. So far, the IPv6 routing protocol for low power and lossy networks (RPL) is considered to fit on IoT infrastructure for achieving the expected network requirements. While RPL meets the IoT network requirements quite well, there are some issues that need to be addressed, such as adaptability to network dynamics. This issue significantly limits the use of RPL in many smart city application scenarios, such as emergency alerts with high traffic flows. As part of a smart city vision, IoT applications are becoming more diverse, which requires context-awareness in routing protocols to support the behavior of the network. To address this issue, we design an objective function that performs the route selection based on fuzzy logic techniques while using contextual information from the application. For this, we present a new context-oriented objective function (COOF) that comprises both nodes as well as link metrics. Further, we suggest two new routing metrics, known as queue fluctuation index (QFI) and residual energy index (REI), which consider the status of queue utilization and remaining energy, respectively. The metrics used are designed to respond to the dynamic needs of the network. The proposed approach has been examined and evaluated in different scenarios when compared to other similar approach and default RPL objective functions. Simulation experiments are conducted in Cooja network simulator for Contiki OS. The evaluation results show that COOF can cope with network dynamics and IoT-based smart city application requirements. Full article
(This article belongs to the Section Networks)
Open AccessReview
A Review of Impedance Matching Techniques in Power Line Communications
Electronics 2019, 8(9), 1022; https://doi.org/10.3390/electronics8091022 - 12 Sep 2019
Viewed by 122
Abstract
Impedance mismatch that degrades signal power transfer and affects communication reliability is a major obstacle for power line communications (PLC). Impedance matching techniques can be designed to effectively compensate for the impedance mismatch between PLC modems and power line networks at a specific [...] Read more.
Impedance mismatch that degrades signal power transfer and affects communication reliability is a major obstacle for power line communications (PLC). Impedance matching techniques can be designed to effectively compensate for the impedance mismatch between PLC modems and power line networks at a specific frequency or for a given frequency band. In this paper, we discuss the tradeoffs that need to be made when designing an effective impedance matching network. We also make a comprehensive review of previous state-of-the-art PLC impedance matching techniques and provide a useful classification of each technique. Finally, we discuss important issues (concerns) and provide suggestions for research directions deserving more attention. This review provides a useful guideline for researchers and manufacturers to quickly understand impedance matching principles and facilitate the design of an effective impedance matching coupler for PLC applications. Full article
(This article belongs to the Special Issue Advances of Power Line Communication (PLC))
Open AccessFeature PaperArticle
DALI LED Driver Control System for Lighting Operations Based on Raspberry Pi and Kernel Modules
Electronics 2019, 8(9), 1021; https://doi.org/10.3390/electronics8091021 - 12 Sep 2019
Viewed by 127
Abstract
Light emitting diodes (LEDs) as an efficient low-consumption lighting technology are being used increasingly in many applications. The move to LED lighting is also changing the way the lighting control systems are designed. Currently, most electronic ballasts and other digital lighting devices implement [...] Read more.
Light emitting diodes (LEDs) as an efficient low-consumption lighting technology are being used increasingly in many applications. The move to LED lighting is also changing the way the lighting control systems are designed. Currently, most electronic ballasts and other digital lighting devices implement the Digital Addressable Lighting Interface (DALI) standard. This paper presents a low-cost, low-power effective DALI LED driver controller, based on open-source Raspberry Pi3 microcontroller prototyping platform. The control software is developed as a Linux kernel module under UBUNTU 18.04.2 LTS patched with PREEMPT_RT (Preemptive Real-time) for real-time processing. This dynamically loaded kernel module performs all the processing, communication and control operations of the Raspberry Pi3-based DALI controller with the DALI LED driver and LED luminaire. Software applications written in C and Python were developed for performance testing purposes. The experimental results showed that the proposed system could efficiently and effectively manage DALI LED drivers and perform lighting operations (e.g. dimming). The system can be used for a variety of purposes from personal lighting control needs and experimental research in control of electronic ballasts and other control gears, devices and sensors, to advanced requirements in professional buildings, including energy management, lighting maintenance and usage. Full article
(This article belongs to the Section Computer Science & Engineering)
Open AccessArticle
Experimental and Numerical Analysis of the Effect of a New Lightning Protection System on Lightning Protection and Aerodynamic Noise Performance of Wind Turbine Blades
Electronics 2019, 8(9), 1020; https://doi.org/10.3390/electronics8091020 - 12 Sep 2019
Viewed by 104
Abstract
In order to tackle the problem of the high failure rate of blades of large wind turbine units due to lightning damage, a new lightning protection system (NLPS) for wind turbine blades is proposed based on the lightning damage mechanism of blades. Firstly, [...] Read more.
In order to tackle the problem of the high failure rate of blades of large wind turbine units due to lightning damage, a new lightning protection system (NLPS) for wind turbine blades is proposed based on the lightning damage mechanism of blades. Firstly, 10 high-voltage discharge tests are performed for blades with and without the NLPS to study the effect of lightning protection. The results show that when the surface of the blade without the NLPS is struck by lightning 10 times, the damage rate of the blade is 100%; for the blade with the NLPS and the lightning attachment position is always on the NLPS in 10 discharge tests, the damage rate of blades is 0% and the lightning protection rate of blades is 100%, indicating that the lightning protection effect for blades with the NLPS is greatly improved. Moreover, the static electric fields of the blades with and without the NLPS are calculated. The results show that the NLPS can shield the electric field around the lower lead wire of the blade, thus effectively reducing the electric field intensity. The NLPS initiates the upward leader more easily than the lower lead wire; therefore, the lightning attachment point is located on the NLPS, thus protecting the blade. Secondly, the aerodynamic and aero-noise characteristics of the blade with and without the NLPS are calculated. The results indicate that the NLPS has little influence on the aerodynamic performance of the blade but has some influence on the aero-noise of the blade. The aero-noise of the airfoil can be reduced at angles of attack of 4°, 8°, 11°, and 15°, but the influence of different phase angles of the airfoil on the amplitude of the sound pressure level (SPL) varies. The aero-noise of the airfoil with the NLPS decreases by 16% and 8% at angles of attack of 4° and 8°, respectively. In general, the design of the NLPS reaches the desired requirements, but it still needs to be further optimized in combination with the blade manufacturing process. Full article
(This article belongs to the Section Power Electronics)
Show Figures

Figure 1

Open AccessArticle
Wideband Noise Interference Suppression for Sparsity-Based SAR Imaging Based on Dechirping and Double Subspace Extraction
Electronics 2019, 8(9), 1019; https://doi.org/10.3390/electronics8091019 - 11 Sep 2019
Viewed by 174
Abstract
Sparsity-based synthetic aperture radar (SAR) imaging has attracted much attention since it has potential advantages in improving the image quality and reducing the sampling rate. However, it is vulnerable to deliberate blanket disturbance, especially wideband noise interference (WBNI), which severely damages the imaging [...] Read more.
Sparsity-based synthetic aperture radar (SAR) imaging has attracted much attention since it has potential advantages in improving the image quality and reducing the sampling rate. However, it is vulnerable to deliberate blanket disturbance, especially wideband noise interference (WBNI), which severely damages the imaging quality. This paper mainly focuses on WBNI suppression for SAR imaging from a new perspective—sparse recovery. We first analyze the impact of WBNI on signal reconstruction by deducing the interference energy projected on the real support set of the signal under different observation parameters. Based on the derived results, we propose a novel WBNI suppression algorithm based on dechirping and double subspace extraction (DDSE), where the signal of interest (SOI) is reconstructed by exploiting the known geometric prior and waveform prior, respectively. The experimental results illustrate that the DDSE-based WBNI suppression algorithm for sparsity-based SAR imaging is effective and outperforms the other algorithms. Full article
Open AccessArticle
The Control Parameter Determination Method for Bidirectional DC-DC Power Converters Interfaced Storage Systems Based on Large Signal Stability Analysis
Electronics 2019, 8(9), 1018; https://doi.org/10.3390/electronics8091018 - 11 Sep 2019
Viewed by 203
Abstract
In DC microgrid (DC-MG), the loads connected with converters under strict control are
considered as CPLs (constant power loads). When the voltage of CPLs decreases, the current
increases and the negative impedance characteristic of CPLs cause instability easily. Fortunately,
appropriate control for energy [...] Read more.
In DC microgrid (DC-MG), the loads connected with converters under strict control are
considered as CPLs (constant power loads). When the voltage of CPLs decreases, the current
increases and the negative impedance characteristic of CPLs cause instability easily. Fortunately,
appropriate control for energy storage units could improve the system stability. However, most
traditional control methods for bidirectional DC-DC power converters (BDC) connected with
battery storage units do not quantitatively consider the stability influences of control parameters.
This paper quantitatively analyzes the stability influence of the BDC current-mode control
parameters and the negative impact of CPLs and derives the control parameter determination
method for BDC interfaced storage systems. Large signal stability constraints are obtained in terms
of mixed potential function. According to the constraints, the large signal stability is improved when
the BDC control parameter kp increases, while the stability is degraded when the power of CPLs
increases. The control parameter determination method is very effective and convenient to apply,
and the appropriate parameter kp for BDC is determined. The regions of asymptotic stability (RAS)
identify that the proposed control parameter determination method could improve the system
stability effectively. The determination method is fully verified by the simulation and experimental results. Full article
(This article belongs to the Section Systems & Control Engineering)
Open AccessArticle
p-STFT: A Robust Parameter Estimator of a Frequency Hopping Signal for Impulsive Noise
Electronics 2019, 8(9), 1017; https://doi.org/10.3390/electronics8091017 - 11 Sep 2019
Viewed by 164
Abstract
Impulsive noise is commonly present in many applications of actual communication networks, leading to algorithms based on the Gaussian model no longer being applicable. A robust parameter estimator of frequency-hopping (FH) signals suitable for various impulsive noise environments, referred to as p [...] Read more.
Impulsive noise is commonly present in many applications of actual communication networks, leading to algorithms based on the Gaussian model no longer being applicable. A robust parameter estimator of frequency-hopping (FH) signals suitable for various impulsive noise environments, referred to as p-STFT, is proposed. The p-STFT estimator replaces the 2-norm by using the generalized version p-norm where 1 < p < 2 for the derivation of the short-time Fourier transform (STFT) as an objective function. It combines impulsive noise processing with any time-frequency analysis algorithm based on STFT. Considering the accuracy of parameter estimation, the double-window spectrogram difference (DWSD) algorithm is used to illustrate the suitability of p-STFT. Computer simulations are mainly conducted in α-stable noise to compare the performance of p-STFT with STFT and fractional low-order STFT (FLOSTFT), Cauchy noise, and Gaussian mixture noise as supplements of different background noises to better demonstrate the robustness and accuracy of p-STFT. Full article
(This article belongs to the Section Circuit and Signal Processing)
Show Figures

Figure 1

Open AccessArticle
Detecting Fake Finger-Vein Data Using Remote Photoplethysmography
Electronics 2019, 8(9), 1016; https://doi.org/10.3390/electronics8091016 - 11 Sep 2019
Viewed by 184
Abstract
Today, biometrics is being widely used in various fields. Finger-vein is a type of biometric information and is based on finger-vein patterns unique to each individual. Various spoofing attacks have recently become a threat to biometric systems. A spoofing attack is defined as [...] Read more.
Today, biometrics is being widely used in various fields. Finger-vein is a type of biometric information and is based on finger-vein patterns unique to each individual. Various spoofing attacks have recently become a threat to biometric systems. A spoofing attack is defined as an unauthorized user attempting to deceive a system by presenting fake samples of registered biometric information. Generally, finger-vein recognition, using blood vessel characteristics inside the skin, is known to be more difficult when producing counterfeit samples than other biometrics, but several spoofing attacks have still been reported. To prevent spoofing attacks, conventional finger-vein recognition systems mainly use the difference in texture information between real and fake images, but such information may appear different depending on the camera. Therefore, we propose a method that can detect forged finger-vein independently of a camera by using remote photoplethysmography. Our main idea is to get the vital sign of arterial blood flow, a biometric measure indicating life. In this paper, we selected the frequency spectrum of time domain signal obtained from a video, as the feature, and then classified data as real or fake using the support vector machine classifier. Consequently, the accuracy of the experimental result was about 96.46%. Full article
(This article belongs to the Section Bioelectronics)
Show Figures

Figure 1

Open AccessArticle
Analytical Solution of Fractional-Order Hyperbolic Telegraph Equation, Using Natural Transform Decomposition Method
Electronics 2019, 8(9), 1015; https://doi.org/10.3390/electronics8091015 - 11 Sep 2019
Viewed by 137
Abstract
In the current paper, fractional-order hyperbolic telegraph equations are considered for analytical solutions, using the decomposition method based on natural transformation. The fractional derivative is defined by the Caputo operator. The present technique is implemented for both fractional- and integer-order equations, showing that [...] Read more.
In the current paper, fractional-order hyperbolic telegraph equations are considered for analytical solutions, using the decomposition method based on natural transformation. The fractional derivative is defined by the Caputo operator. The present technique is implemented for both fractional- and integer-order equations, showing that the current technique is an accurate analytical instrument for the solution of partial differential equations of fractional-order arising in all branches of applied sciences. For this purpose, several examples related to hyperbolic telegraph models are presented to explain the procedure of the suggested method. It is noted that the procedure of the present technique is simple, straightforward, accurate, and found to be a better mathematical technique to solve non-linear fractional partial differential equations. Full article
Show Figures

Figure 1

Open AccessArticle
Energy Optimization for Software-Defined Data Center Networks Based on Flow Allocation Strategies
Electronics 2019, 8(9), 1014; https://doi.org/10.3390/electronics8091014 - 11 Sep 2019
Viewed by 171
Abstract
Nowadays, energy consumption has become an important issue in data center networks. The most promising energy-saving schemes are those that shut down unnecessary network devices and links while meeting the demand of traffic loads. Existing research mainly focuses on the strategies of energy [...] Read more.
Nowadays, energy consumption has become an important issue in data center networks. The most promising energy-saving schemes are those that shut down unnecessary network devices and links while meeting the demand of traffic loads. Existing research mainly focuses on the strategies of energy savings in software-defined data center networks (SD-DCN). Few studies have considered both energy savings and the quality of service (QoS) of the traffic load. In this paper, we investigate the energy savings guaranteed by traffic load satisfaction ratio. To ensure the minimum-power consumption in data centers, we formulate the SD-DCN energy consumption optimization problem as an Integer Linear Programming model. To achieve a high success rate for traffic transmission, we propose three flow scheduling strategies. On this foundation, we propose a strategy-based Minimum Energy Consumption (MEC) heuristic algorithm to ensure the QoS satisfaction ratio in the process of energy optimization. The results show that our algorithm can save energy efficiently under the conditions of low traffic load and medium traffic load. Under high traffic load, our algorithm can achieve better network performance than existing solutions in terms of quality of service satisfaction ratio of flow allocation. Full article
(This article belongs to the Section Computer Science & Engineering)
Show Figures

Figure 1

Open AccessArticle
Design of a SIW Variable Phase Shifter for Beam Steering Antenna Systems
Electronics 2019, 8(9), 1013; https://doi.org/10.3390/electronics8091013 - 11 Sep 2019
Viewed by 180
Abstract
This paper proposes a new beam steering antenna system consisting of two variable reflection-type phase shifters, a 3 dB coupler, and a 90° phase transition. The entire structure is designed and fabricated on a single layer of substrate integrated waveguide (SIW), which makes [...] Read more.
This paper proposes a new beam steering antenna system consisting of two variable reflection-type phase shifters, a 3 dB coupler, and a 90° phase transition. The entire structure is designed and fabricated on a single layer of substrate integrated waveguide (SIW), which makes it a low loss and low-profile antenna system. Surface mount tuning varactor diodes are chosen as electrical phase control elements. By changing the biasing voltage of the varactor diodes in the phase shifter circuits, the far-field radiation pattern of the antenna steers from −25° to 25°. The system has a reflection coefficient better than −10 dB for a 2 GHz bandwidth centered at 17 GHz, a directive radiation pattern with a maximum of 10.7 dB gain at the mid-band frequency, and cross polarization better than 20 dB. A prototype is fabricated and measured for design verification. The measured far-field radiation patterns, co and cross polarization, and the reflection coefficient of the antenna system agree with simulated results. Full article
(This article belongs to the Special Issue Millimeter-Wave (mmWave) Communications)
Show Figures

Figure 1

Open AccessArticle
State of Charge Estimation for Lithium-Ion Batteries Based on Temperature-Dependent Second-Order RC Model
Electronics 2019, 8(9), 1012; https://doi.org/10.3390/electronics8091012 - 10 Sep 2019
Viewed by 173
Abstract
Accurate estimation of battery state of charge (SOC) is of great significance for extending battery life, improving battery utilization, and ensuring battery safety. Aiming to improve the accuracy of SOC estimation, in this paper, a temperature-dependent second-order RC equivalent circuit model is established [...] Read more.
Accurate estimation of battery state of charge (SOC) is of great significance for extending battery life, improving battery utilization, and ensuring battery safety. Aiming to improve the accuracy of SOC estimation, in this paper, a temperature-dependent second-order RC equivalent circuit model is established for lithium-ion batteries, based on the battery electrical characteristics at different ambient temperatures. Then, a dual Kalman filter algorithm is proposed to estimate the battery SOC, using the proposed equivalent circuit model. The SOC estimation results are compared with the SOC value obtained from experiments, and the estimation errors under different temperature conditions are found to be within ±0.4%. These results prove that the proposed SOC estimation algorithm, based on a temperature-dependent second-order RC equivalent circuit model, provides accurate SOC estimation performance with high temperature adaptability and robustness. Full article
Show Figures

Figure 1

Open AccessFeature PaperArticle
Spectrum Occupancy Measurements and Analysis in 2.4 GHz WLAN
Electronics 2019, 8(9), 1011; https://doi.org/10.3390/electronics8091011 - 10 Sep 2019
Viewed by 180
Abstract
High time resolution spectrum occupancy measurements and analysis are presented for 2.4 GHz WLAN signals. A custom-designed wideband sensing engine records the received power of signals, and its performance is presented to select the decision threshold required to define the channel state (busy/idle). [...] Read more.
High time resolution spectrum occupancy measurements and analysis are presented for 2.4 GHz WLAN signals. A custom-designed wideband sensing engine records the received power of signals, and its performance is presented to select the decision threshold required to define the channel state (busy/idle). Two sets of measurements are presented where data were collected using an omni-directional and directional antenna in an indoor environment. Statistics of the idle time windows in the 2.4 GHz WLAN are analyzed using a wider set of distributions, which require fewer parameters to compute and are more practical for implementation compared to the widely-used phase type or Gaussian mixture distributions. For the omni-directional antenna, it was found that the lognormal and gamma distributions can be used to model the behavior of the idle time windows under different network traffic loads. In addition, the measurements show that the low time resolution and angle of arrival affect the statistics of the idle time windows. Full article
Show Figures

Figure 1

Open AccessArticle
Numerical Laplace Inversion Method for Through-Silicon Via (TSV) Noise Coupling in 3D-IC Design
Electronics 2019, 8(9), 1010; https://doi.org/10.3390/electronics8091010 - 10 Sep 2019
Viewed by 168
Abstract
Typical 3D integrated circuit structures based on through-silicon vias (TSVs) are complicated to study and analyze. Therefore, it seems important to find some methods to investigate them. In this paper, a method is proposed to model and compute the time-domain coupling noise in [...] Read more.
Typical 3D integrated circuit structures based on through-silicon vias (TSVs) are complicated to study and analyze. Therefore, it seems important to find some methods to investigate them. In this paper, a method is proposed to model and compute the time-domain coupling noise in 3D Integrated Circuit (3D-IC) based on TSVs. It is based on the numerical inversion Laplace transform (NILT) method and the chain matrices. The method is validated using some experimental results and the Pspice and Matlab tools. The results confirm the effectiveness of the proposed technique and the noise is analyzed in several cases. It is found that TSV noise coupling is affected by different factors such as source characteristics, horizontal interconnections, and the type of Inputs and Outputs (I/O) drivers. Full article
(This article belongs to the Special Issue Signal Processing and Analysis of Electrical Circuit)
Show Figures

Figure 1

Open AccessArticle
An Energy-Efficient and Fault-Tolerant Topology Control Game Algorithm for Wireless Sensor Network
Electronics 2019, 8(9), 1009; https://doi.org/10.3390/electronics8091009 - 09 Sep 2019
Viewed by 233
Abstract
Due to resource constraints and severe conditions, wireless sensor networks should be self-adaptive to maintain certain desirable properties, such as energy efficiency and fault tolerance. In this paper, we design a practical utility function that can effectively balance transmit power, residual energy, and [...] Read more.
Due to resource constraints and severe conditions, wireless sensor networks should be self-adaptive to maintain certain desirable properties, such as energy efficiency and fault tolerance. In this paper, we design a practical utility function that can effectively balance transmit power, residual energy, and network connectivity, and then we investigate a topology control game model based on non-cooperative game theory. The theoretical analysis shows that the topology game model is a potential game and can converge to a state of the Nash equilibrium. Based on this model, an energy-efficient and fault-tolerant topology control game algorithm, EFTCG, is proposed to adaptively constructs a network topology. In turn, we present two subalgorithms: EFTCG-1 and EFTCG-2. The former just guarantees network single connectivity, but the latter can guarantee network biconnectivity. We evaluate the energy-efficient effect of EFTCG-1. Meanwhile, we also analyze the fault-tolerant performance of EFTCG-2. The simulation results verify the validity of the utility function. EFTCG-1 can efficiently prolong the network lifetime compared with other game-based algorithms, and EFTCG-2 performs better in robustness, although does not significantly reduce the network lifetime. Full article
Show Figures

Figure 1

Open AccessArticle
Balancing Distributed Key-Value Stores with Efficient In-Network Redirecting
Electronics 2019, 8(9), 1008; https://doi.org/10.3390/electronics8091008 - 09 Sep 2019
Viewed by 167
Abstract
Today’s cloud-based online services are underpinned by distributed key-value stores (KVSs). Keys and values are distributed across back-end servers in such scale-out systems. One primary real-life performance bottleneck occurs when storage servers suffer from load imbalance under skewed workloads. In this paper, we [...] Read more.
Today’s cloud-based online services are underpinned by distributed key-value stores (KVSs). Keys and values are distributed across back-end servers in such scale-out systems. One primary real-life performance bottleneck occurs when storage servers suffer from load imbalance under skewed workloads. In this paper, we present KVSwitch, a centralized self-managing load balancer that leverages the power and flexibility of emerging programmable switches. The balance is achieved by dynamically predicting the hot items and by creating replication strategies according to KVS loading. To overcome the challenges in realizing KVSwitch given the limitations of the switch hardware, we decompose KVSwitch’s functions and carefully design them for the heterogeneous processors inside the switch. We prototype KVSwitch in a Tofino switch. Experimental results show that our solution can effectively keep the KVS servers balanced even under highly skewed workloads. Furthermore, KVSwitch only replicates 70 % of hot items and consumes 9.88 % of server memory rather than simply replicating all hot items to each server. Full article
(This article belongs to the Section Networks)
Show Figures

Figure 1

Previous Issue
Back to TopTop