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Topic Review
Takagi–Sugeno Fuzzy-PI Controller Hardware
The intelligent system Field Programmable Gate Array (FPGA) is represented as Takagi--Sugeno Fuzzy-PI controller. The implementation uses a fully parallel strategy associated with a hybrid bit format scheme (fixed-point and floating-point). Two hardware designs are proposed; the first one uses a single clock cycle processing architecture, and the other uses a pipeline scheme. The bit accuracy was tested by simulation with a nonlinear control system of a robotic manipulator. The area, throughput, and dynamic power consumption of the implemented hardware are used to validate and compare the results of this proposal. The results achieved allow the use of the proposed hardware in applications with high-throughput, low-power, and ultra-low-latency requirements such as teleoperation of robot manipulators, tactile internet, or industry 4.0 automation, among others.
  • 1.0K
  • 29 Oct 2020
Topic Review
LoRaWAN Technology
Low-power wide-area network (LPWAN) technologies play a pivotal role in IoT applications, owing to their capability to meet the key IoT requirements (e.g., long range, low cost, small data volumes, massive device number, and low energy consumption). Between all obtainable LPWAN technologies, long-range wide-area network (LoRaWAN) technology has attracted much interest from both industry and academia due to networking autonomous architecture and an open standard specification. 
  • 1.0K
  • 21 Jan 2022
Topic Review
Massive MIMO Techniques for 5G
The general concept of massive MIMO is defined as a physical-layer technology which equips each BS with a huge number of active antennas that can be used to spatially multiplex many UEs so that it is possible to communicate with them on the same time-frequency resource. The spectral efficiency per cell can be improved by orders-of magnitude over classical cellular networks by coping with the signal attenuation and interference through spatial signal processing with techniques such as receive combining and transmit precoding. To resume, massive MIMO is an upgraded version of the Space-Division Multiple Access (SDMA), pushing the spatial multiplexing to an extreme level.
  • 1.0K
  • 12 Aug 2021
Topic Review
Facial Expression Recognition
Facial expression recognition (FER) is a challenging problem in the fields of pattern recognition and computer vision. The recent success of convolutional neural networks (CNNs) in object detection and object segmentation tasks has shown promise in building an automatic deep CNN-based FER model. However, in real-world scenarios, performance degrades dramatically owing to the great diversity of factors unrelated to facial expressions, and due to a lack of training data plus an intrinsic imbalance in the existing facial emotion datasets. To tackle these problems, this paper not only applies deep transfer learning techniques but also proposes a novel loss function called weighted-cluster loss, which is used during the fine-tuning phase. Specifically, the weighted-cluster loss function simultaneously improves the intra-class compactness and the inter-class separability by learning a class center for each emotion class. It also takes the imbalance in a facial expression dataset into account by giving each emotion class a weight based on its proportion of the total number of images. In addition, a recent, successful deep CNN architecture, pre-trained in the task of face identification with the VGGFace2 database from the Visual Geometry Group at Oxford University, is employed and fine-tuned using the proposed loss function to recognize eight basic facial emotions from the AffectNet database of facial expression, valence, and arousal computing in the wild. Experiments on an AffectNet real-world facial dataset demonstrate that our method outperforms the baseline CNN models that use either weighted-softmax loss or center loss.
  • 1.0K
  • 09 Feb 2021
Topic Review
Field Measurement Studies on Indoor Air Quality
The Indoor Air Quality (IAQ) is one of the key factors that influence the quality of the indoor environment, as well as the human health.
  • 1.0K
  • 16 Feb 2022
Topic Review
Photovoltaic Systems (PVSs)
In a grid-connected photovoltaic system (PVS) synchronization and islanding detection techniques have to operate in coordination. Abnormal conditions can arise on the utility grid which require a prompt response from the PVS, hence the information provided by the synchronization system are fundamental for the grid voltage monitoring. The islanding detection techniques are based also on the information provided by the synchronization techniques and some islanding detection techniques require additional synchronization systems. Besides, after an islanding event, the PVS reconnection procedure has to be managed with two synchronization systems. For all these reasons synchronization and islanding detection issues have been analyzed together. 
  • 1.0K
  • 13 Jul 2020
Topic Review
PV based EV Charging Modelling
Electric vehicles (EVs) are one of a prominent solution for the sustainability issues needing dire attention like global warming, depleting fossil fuel reserves, and greenhouse gas (GHG) emissions. Conversely, EVs are shown to emit higher emissions (measured from source to tailpipe) for the fossil fuel-based countries, which necessitates renewable energy sources (RES) for maximizing EV benefits. EVs can also act as a storage system, to mitigate the challenges associated with RES and to provide the grid with ancillary services, such as voltage regulation, frequency regulation, spinning reserve, etc. For extracting maximum benefits from EVs and minimizing the associated impact on the distribution network, modelling optimal integration of EVs in the network is required.
  • 1.0K
  • 02 Nov 2023
Topic Review
Smart Charging of Electric Vehicles
There is a continuous and fast increase in electric vehicles (EVs) adoption in many countries due to the reduction of EVs prices, governments’ incentives and subsidies on EVs, the need for energy independence, and environmental issues. It is expected that EVs will dominate the private cars market in the coming years. These EVs charge their batteries from the power grid and may cause severe effects if not managed properly. On the other hand, they can provide many benefits to the power grid and get revenues for EV owners if managed properly.  This article presents the potential negative impacts of EVs charging on electric power systems mainly due to uncontrolled charging and how through controlled charging and discharging those impacts can be reduced and become even positive impacts through an energy management for electric vehicles.
  • 1.0K
  • 01 Nov 2023
Topic Review
Plug-in Electric Vehicles in Germany
The adoption of plug-in electric vehicles in Germany is actively supported by the German Federal Government. Under its National Plattform for Electric Mobility, Chancellor Angela Merkel set an initial goal in 2010 to deploy one million electric vehicles on German roads by 2020. Initially, the government did not provide subsidies to promote sales of plug-in electric vehicles, however, by the end of 2014 it was recognized that the country was well behind the set sales targets. A purchase bonus scheme was approved in 2016, but premium cars were not eligible to the incentive. In order to meet the climate targets for the transport sector, in 2016 the government set the goal to have from 7 to 10 million plug-in electric cars on the road by 2030, and 1 million charging points deployed by 2030. In June 2020, and as a result of the economic impact of the COVID-19 pandemic, the government approved a recovery plan which included €8 billion to promote electric vehicle adoption and deployment of charging infrastructure. The purchase bonus for all-electric cars was raised temporarily from €6,000 to €9,000 for cars costing less than €40,000. There are lower bonuses for the purchase of plug-in hybrids, used cars and for leasing. The additional bonus will be available until the end of 2025. The initial one million goal was achieved in July 2021. The stock of plug-in electric vehicles in Germany is the largest in Europe, and (As of July 2021), there were 1 million plug-in electric vehicles on the road, including buses and commercial vehicles. The German fleet in use consists of 54% all-electric vehicles and 46% plug-in hybrids. (As of December 2019), Germany had a stock of 21,890 light-duty electric commercial vehicles, the second largest in Europe after France. (As of March 2020), the country had 27,730 public charging stations. The plug-in electric car segment market share was 1.58% in 2017 and 1.9% in 2018. The segment market share rose to 3.10% in 2019, and despite the global strong decline in car sales brought by the COVID-19 pandemic, the uptake rate achieved a record 13.6% in 2020. (As of January 2021), the stock of German plug-in electric cars on the road totaled 588,944 units, representing 1.2% of all registered passenger cars, up from 0.5% the previous year. In 2019, Germany surpassed Norway as Europe's top selling country market in terms of annual sales, and with a record volume of 394,632 plug-in passenger cars registered in 2020, up 263% from 2019, Germany listed for a second year running as the best selling European plug-in market. Both years, the German market led both the fully electric and plug-in hybrid segments. The only country that outsold Germany in 2020 was China.
  • 1.0K
  • 10 Oct 2022
Topic Review
Application of Optical Fibers in Temperature Monitoring
The current generation is witnessing a huge interest in optical waveguides due to their salient features: they are of low cost, immune to electromagnetic interference, easy to multiplex, have a compact size, etc. These features of optical fibers make them a useful tool for various sensing applications including in medicine, automotives, biotechnology, food quality control, aerospace, physical and chemical monitoring. Among all the reported applications, optical wave guides have been widely exploited to measure the physical and chemical variations in the surrounding environment. Optical fiber-based temperature sensors have played a crucial role in this decade to detect high fever and tackle COVID-19-like pandemics. Recognizing the major developments in the field of optical fibers, this entry provides recent progress in temperature sensors utilizing several sensing configurations including conventional fiber, photonic crystal fiber, and Bragg grating fibers. Additionally, this entry also highlights the advantages, limitations, and future possibilities in this area.
  • 1.0K
  • 08 Mar 2023
Topic Review
Switchgear
In an electric power system, switchgear is the combination of electrical disconnect switches, fuses or circuit breakers used to control, protect and isolate electrical equipment. Switchgear is used both to de-energize equipment to allow work to be done and to clear faults downstream. This type of equipment is directly linked to the reliability of the electricity supply. The earliest central power stations used simple open knife switches, mounted on insulating panels of marble or asbestos. Power levels and voltages rapidly escalated, making opening manually operated switches too dangerous for anything other than isolation of a de-energized circuit. Oil-filled equipment allowed arc energy to be contained and safely controlled. By the early 20th century, a switchgear line-up would be a metal-enclosed structure with electrically operated switching elements, using oil circuit breakers. Today, oil-filled equipment has largely been replaced by air-blast, vacuum, or SF6 equipment, allowing large currents and power levels to be safely controlled by automatic equipment. High-voltage switchgear was invented at the end of the 19th century for operating motors and other electric machines. The technology has been improved over time and can now be used with voltages up to 1,100 kV. Typically, switchgear in substations are located on both the high- and low-voltage sides of large power transformers. The switchgear on the low-voltage side of the transformers may be located in a building, with medium-voltage circuit breakers for distribution circuits, along with metering, control, and protection equipment. For industrial applications, a transformer and switchgear line-up may be combined in one housing, called a unitized substation (USS).
  • 1.0K
  • 21 Nov 2022
Topic Review
Sensor and Actuator Fault Diagnosis
Sensors and actuators are key components in the robot system, but their working environment is very complex, with electromagnetic interference, vibration, etc., which will affect the output of the sensors and then the actuators. Moreover, the variable load on manipulators is also a challenge for system state feedback or estimation. All of the above factors make the faults diagnosis of robot system sensors and actuators an urgent task. The DCNN is used to deal with sensor and actuator faults of robot joints, such as gain error, offset error, and malfunction for both sensors and actuators, and different fault types are diagnosed using the trained neural network.
  • 1.0K
  • 29 Jun 2021
Topic Review
Piezoelectric MEMS Laterally Vibrating Resonators
Piezoelectric MEMS Laterally Vibrating Resonators (LVRs), which belong to one type of micromachined resonators that uses piezoelectric transduction, are characterized by dominant mechanical vibration in the lateral direction (within the plane of the device). In piezoelectric MEMS LVRs, the electric field is mainly applied across the thickness of the piezoelectric film to generate a lateral strain within the plane of the device with suspended free edges. Due to the lithographically definable resonant frequency, piezoelectric LVRs feature wide operation frequency coverage (from tens of MHz to several GHz) and provide a pathway towards realizing a multi-frequency integrated solution on a single chip. Depending on the structure of resonators, piezoelectric MEMS LVRs can be categorized into two types. The first type of LVRs consists of a piezoelectric film, both as the transducer and acoustic cavity. The second type of LVRs uses the thin piezoelectric film as a transducer only while having most of the acoustic energy propagating in the underlying thicker substrate. Such resonators are usually referred to as thin-film piezoelectric-on-substrate (TPoS) resonators. Typical applications of piezoelectric MEMS LVRs include resonant sensors, oscillators and RF filters.
  • 1.0K
  • 14 Sep 2020
Topic Review
LPWAN
LPWAN stands for Low Power Wide Area Network;  LPWAN provides long-distance communication for rural and urban areas to support IIoT devices considered by a ten-year provision time to acclimate IIoT applications with higher extensibility, availability of intelligent monitoring infrastructure for a small portion of data exchanges. LoRa is favorable to use with smart sensing applications working IIoT non-authored spectrum. NBIoT is suitable for supporting agriculture and environmental data collection and observations, industrial data tracking and monitoring, inventory tracking, smart billing, and smart buildings, smart metering, and smart cities. Machine-to-machine (M2M) communication uses the Bluetooth Low Energy (BLE) technique for the data communication, the other IIoT applications used in healthcare, smart agriculture, intelligent home, smart vehicles, smart city, smart gadgets, and industries use the cognitive LPWAN, LoRA, Sigfox.  There is a need to mix most LPWAN technologies in heterogeneous IIoT applications to provide more efficient and convenient intelligent services. In heterogeneous IIoT applications, there a need to mix most LPWAN technologies to provide more efficient and convenient intelligent services. This will be deployed by cognitive LPWAN 
  • 1.0K
  • 20 Jan 2021
Topic Review
Meo (Telecommunication Service)
MEO is a mobile and fixed telecommunications service and brand from Altice Portugal (formerly Portugal Telecom), managed by MEO - Serviços de Comunicações e Multimédia. The service was piloted in Lisbon in 2006 and was later extended to Porto and Castelo Branco.
  • 1.0K
  • 03 Nov 2022
Topic Review
Ultra-Reliable Low-Latency V2X Communications
Vehicular communication is a promising technology that has been announced as a main use-case of the fifth-generation cellular system (5G). Vehicle-to-everything (V2X) is the vehicular communication paradigm that enables the communications and interactions between vehicles and other network entities, e.g., road-side units (RSUs). This promising technology faces many challenges related to reliability, availability and security of the exchanged data. 
  • 1.0K
  • 07 Jan 2022
Topic Review
Flying Ad Hoc Network
Unmanned aerial vehicles (UAVs), or drones, have made them able to communicate and collaborate, forming flying ad hoc networks (FANETs). FANETs are becoming popular in many application domains, including precision agriculture, goods delivery, construction, environment and climate monitoring, and military surveillance. These interesting new avenues for the use of UAVs are motivating researchers to rethink the existing research on FANETs. 
  • 998
  • 01 Dec 2022
Topic Review
Machines Additive Manufacturing
Modern-day machine applications require extraordinary performance parameters such as high power-density, integrated functionalities, improved thermal, mechanical & electromagnetic properties. Additive manufacturing (AM)offers a higher degree of design flexibility to achieve these performance parameters, which is impossible to realize through conventional manufacturing techniques.
  • 996
  • 26 Aug 2021
Topic Review
Direct Current Distribution System Configurations
The developments in renewable energy installations in buildings have highlighted the potential improvement in energy efficiency provided by direct current (DC) distribution over traditional alternating current (AC) distribution. Despite the progress and optimal efficiency of DC distribution system implementation, there is still no consensus on standardization and regulation. It has been shown that the DC system performance could vary in terms of efficiency depending on load profile, utilized renewable energy sources, and utility grid integration.
  • 995
  • 11 Oct 2022
Topic Review
Harmonics Affect Power Quality
Harmonic estimation is essential for mitigating or suppressing harmonic distortions in power systems. 
  • 995
  • 04 May 2023
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