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Topic Review
Electrically Powered Spacecraft Propulsion
An electrically powered spacecraft propulsion system uses electrical, and possibly also magnetic fields, to change the velocity of a spacecraft. Most of these kinds of spacecraft propulsion systems work by electrically expelling propellant (reaction mass) at high speed. Electric thrusters typically use much less propellant than chemical rockets because they have a higher exhaust speed (operate at a higher specific impulse) than chemical rockets. Due to limited electric power the thrust is much weaker compared to chemical rockets, but electric propulsion can provide thrust for a longer time. Electric propulsion is now a mature and widely used technology on spacecraft. Russia n satellites have used electric propulsion for decades. (As of 2019), over 500 spacecraft operated throughout the Solar System use electric propulsion for station keeping, orbit raising, or primary propulsion. In the future, the most advanced electric thrusters may be able to impart a delta-v of 100 km/s, which is enough to take a spacecraft to the outer planets of the Solar System (with nuclear power), but is insufficient for interstellar travel. An electric rocket with an external power source (transmissible through laser on the photovoltaic panels) has a theoretical possibility for interstellar flight. However, electric propulsion is not suitable for launches from the Earth's surface, as it offers too little thrust. On a journey to Mars, an electrically powered ship might be able to carry 70% of its initial mass to the destination, while a chemical rocket could carry only a few percent.
  • 1.8K
  • 23 Nov 2022
Topic Review
Autonomous Vehicle
An Autonomous Vehicle (AV), or a driverless car, or a self-driving vehicle is a car, bus, truck, or any other vehicle that is able to drive from point A to point B and perform all necessary driving operations and functions without any human intervention. An Autonomous Vehicle is normally equipped with different types of sensors to perceive the surrounding environment, including Normal Vision Cameras, Infrared Cameras, RADAR, LiDAR, and Ultrasonic Sensors.  An autonomous vehicle should be able to detect and recognise all type of road users including surrounding vehicles, pedestrians, cyclists, traffic signs, road markings, and can segment the free spaces, intersections, buildings, and trees to perform a safe driving task.  Currently, no realistic prediction expects we see fully autonomous vehicles earlier than 2030. 
  • 1.8K
  • 17 Feb 2021
Topic Review
Hybrid HVAC–HVDC Grids
The concept of hybrid high-voltage alternating current (HVAC) and high-voltage direct current (HVDC) grid systems brings a massive advantage to reduce AC line loading, increased utilization of network infrastructure, and lower operational costs. However, it comes with issues, such as integration challenges, control strategies, optimization control, and security. The combined objectives in hybrid HVAC–HVDC grids are to achieve the fast regulation of DC voltage and frequency, optimal power flow, and stable operation during normal and abnormal conditions.
  • 1.8K
  • 20 Sep 2021
Topic Review
Cuff-Less Blood Pressure Monitoring Technology
Initial calibration is a great challenge for cuff-less blood pressure (BP) measurement. The traditional one point-to-point (oPTP) calibration procedure had a strong sensitivity in the selection of initial value because of only using one sample/point to obtain unknown parameters of specific model in a calm state. In this study, a mean point-to-point (mPTP) paring calibration method through averaging and balancing calm or peaceful state was proposed for the first time. Thus, based on mPTP, a factor point-to-point (fPTP) paring calibration method through introducing the penalty factor was further proposed to improve and optimize the performance of BP estimation.
  • 1.8K
  • 29 Oct 2020
Topic Review
Commercialization of Electric Vehicles
Electric Vehicles (EVs) are a promising alternative to internal combustion engine vehicles as the city is transitioning to clean energy.
  • 1.7K
  • 10 Feb 2022
Topic Review
Recent Advances of Wearable Sweat-Sensing Devices
A sweat-sensing device requires a wearable device for the temporary attachment of its main components, including sensors, sweat collection devices, and electronic devices to the body’s skin region.
  • 1.7K
  • 21 Oct 2022
Topic Review
Robust Speed Control Techniques
The permanent magnet synchronous motor (PMSM) is a highly efficient energy saving machine. Due to its simple structural characteristics, good heat radiation capability, and high efficiency, PMSMs are gradually replacing AC induction motors in many industrial applications. The PMSM has a nonlinear system and lies on parameters that differ over time with complex high-class dynamics. To achieve the excessive performance operation of a PMSM, it essentially needs a speed controller for providing accurate speed tracking, slight overshoot, and robust disturbance repulsion. 
  • 1.7K
  • 03 Mar 2022
Topic Review
Audi E-tron
The Audi e-tron family is a series of electric and hybrid concept cars shown by Audi from 2009 onwards. In 2012 Audi unveiled a plug-in hybrid version, the Audi A3 Sportback e-tron, released to retail customers in Europe in August 2014, and slated for the U.S. in 2015.
  • 1.7K
  • 12 Aug 2023
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.
  • 1.7K
  • 11 Oct 2022
Topic Review
Passenger Traffic-Flows
Information and Communication Technology (ICT) enabled optimisation of train's passenger traffic flows is a key consideration of transportation under Smart City planning (SCP). Traditional mobility prediction based optimisation and encryption approaches are reactive in nature; however, Artificial Intelligence (AI) driven proactive solutions are required for near real-time optimisation. Leveraging the historical passenger data recorded via Radio Frequency Identification (RFID) sensors installed at the train stations, mobility prediction models can be developed to support and improve the railway operational performance vis-a-vis 5G and beyond. In this paper we have analysed the passenger traffic flows based on an Access, Egress and Interchange (AEI) framework to support train infrastructure against congestion, accidents, overloading carriages and maintenance. This paper predominantly focuses on developing passenger flow predictions using Machine Learning (ML) along with a novel encryption model that is capable of handling the heavy passenger traffic flow in real-time. We have compared and reported the performance of various ML driven flow prediction models using real-world passenger flow data obtained from London Underground and Overground (LUO). Extensive spatio-temporal simulations leveraging realistic mobility prediction models show that an AEI framework can achieve 91.17% prediction accuracy along with secure and light-weight encryption capabilities. Security parameters such as correlation coefficient (<0.01), entropy (>7.70), number of pixel change rate (>99%), unified average change intensity (>33), contrast (>10), homogeneity (<0.3) and energy (<0.01) prove the efficacy of the proposed encryption scheme.
  • 1.7K
  • 29 Jan 2021
Topic Review
Laser-Induced Graphene Based Flexible Electronic Devices
Since it was reported in 2014, laser-induced graphene (LIG) has received growing attention for its fast speed, non-mask, and low-cost customizable preparation, and has shown its potential in the fields of wearable electronics and biological sensors that require high flexibility and versatility. The achievements of LIG based devices for detecting diverse bio-signal, serving as monitoring human motions, energy storage, and heaters are highlighted here, referring to the advantages of LIG in flexible designability, excellent electrical conductivity, and diverse choice of substrates.
  • 1.7K
  • 09 Feb 2022
Topic Review
EV Charging
EVs or Plug-In EVs (PEVs) are powered by rechargeable batteries and classified in the green technology vehicles, which will replace the Internal Combustion Engine (ICE). The transferring technologies from petroleum-based transportation to green transportation has a number of benefits in several areas like economic, environment, and technical support.
  • 1.7K
  • 31 Oct 2023
Topic Review
Lithium-Ion Batteries-Energy Storage
Lithium-ion (Li-ion) batteries are a good energy storage solution for plug-in electric vehicles. However, the performance and health of these batteries is highly dependent on the use case, including operating temperature, power consumption profile, and control strategy (heavy forced alternating charge–discharge modes) imposed by the battery management system.
  • 1.7K
  • 16 Dec 2021
Topic Review
Allying Meta-Structures with Diverse Optical Waveguides for Integrated-Photonics
Recent years have witnessed tremendous interest in synergizing various functional subwavelength structures into diverse optical waveguide platforms to enable versatile photonic meta-devices. The advancement of meta-waveguides not only extends meta-optics into the manipulation of guided wave, but may also reshape the landscapes of photonic integrated circuits and massive emergent applications. A recent review paper outlined latest progress on meta-waveguides-based photonics devices and systems. Both forward and inverse designed scenarios are cataloged showcasing vibrant opportunities.
  • 1.7K
  • 13 Dec 2021
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).
  • 1.7K
  • 21 Nov 2022
Topic Review
Harmonics Affect Power Quality
Harmonic estimation is essential for mitigating or suppressing harmonic distortions in power systems. 
  • 1.7K
  • 04 May 2023
Topic Review
Secure Key Establishment Mechanism
Key establishment means the process of generating a usable and shared secret key between one or more entities. Key establishment includes key generation, key agreement, key distribution and so on. Among them, key generation and key agreement refer to the process of establishing a shared key between entities, in which no entity can determine the value of the key in advance. With smart sensing systems, the communications between sensors, actuators, and edge computing systems and robots are prone to be attacked due to the highly dynamic and distributed environment. Since smart robots are often distributed in open environments, as well as due to their limited hardware resources and security protection capabilities, the security requirements of their keys cannot be met with traditional key distribution algorithms. In this paper, we propose a new mechanism of key establishment based on high-order polynomials to ensure the safe key generation and key distribution. Experiments show that the key establishment mechanism proposed in this paper guarantees the security of keys; its storage cost and communication cost are smaller than state-of-the-art mechanisms; and it allows robot components to join and leave the network dynamically, which is more suitable for multi-robot systems.
  • 1.7K
  • 29 Oct 2020
Topic Review
Flexible Electronic System
Flexible Electronic System (FES,) known as flex circuits, have been growing rapidly in industries and organisations such as medical healthcare, energy and power, aerospace, industrial automation, military and defence, sports and entertainment are now the array of various devices are generally comprised of organic substances as a substrate.
  • 1.7K
  • 18 Mar 2021
Topic Review
Oscilloscope History
The history of the oscilloscope reaches back to the first recordings of waveforms with a galvanometer coupled to a mechanical drawing system in the second decade of the 19th century. The modern day digital oscilloscope is a consequence of multiple generations of development of the oscillograph, cathode-ray tubes, analog oscilloscopes, and digital electronics.
  • 1.7K
  • 21 Nov 2022
Topic Review
Optimizing Use of RTKLIB for Smartphone-Based GNSS Measurements
The Google Smartphone Decimeter Challenge (GSDC) was a competition held in 2021, where data from a variety of instruments useful for determining a phone’s position (signals from GPS satellites, accelerometer readings, gyroscope readings, etc.) using Android smartphones were provided to be processed/assessed in regard to the most accurate determination of the longitude and latitude of user positions. One of the tools that can be utilized to process the GNSS measurements is RTKLIB. RTKLIB is an open-source GNSS processing software tool that can be used with the GNSS measurements, including code, carrier, and doppler measurements, to provide real-time kinematic (RTK), precise point positioning (PPP), and post-processed kinematic (PPK) solutions.
  • 1.7K
  • 30 May 2022
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