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Topic Review
Biography
Topic Review
Video
Modular Multilevel Converters
A modular multilevel converter (MMC) is an advanced voltage source converter applicable to a wide range of medium and high-voltage applications. It has competitive advantages such as quality output performance, high modularity, simple scalability, and low voltage and current rating demand for the power switches. The generalized configuration of a three-phase MMC is comprised of a DC terminal, an AC terminal, and a converting kernel involving three phase legs. Each leg/phase has two symmetric arms referred to as the upper arm and lower arm. The upper arm and lower arm contain a group of identical submodules connected in series together with a chock inductor to suppress high-frequency components in the arm current. The research interests of MMCs are primarily associated with the topologies, mathematical modeling, output voltage and current control, submodule balancing control, circulating current control, and modulation methods. And the incorporation of wideband gap (WBG) semiconductors are prospected to facilitate the MMC application with further advantages of high-voltage and high-power operations, low power losses, high efficiency, improved reliability, and reduced module size and cooling system.
23.0K
18 Aug 2021
Topic Review
Sensors for Health Monitoring
The use of wearable equipment and sensing devices to monitor physical activities, whether for well-being, sports monitoring, or medical rehabilitation, has expanded rapidly due to the evolution of sensing techniques, cheaper integrated circuits, and the development of connectivity technologies. In this scenario, this paper presents a state-of-the-art review of sensors and systems for rehabilitation and health monitoring. Although we know the increasing importance of data processing techniques, our focus was on analyzing the implementation of sensors and biomedical applications. Although many themes overlap, we organized this review based on three groups: Sensors in Healthcare, Home Medical Assistance, and Continuous Health Monitoring; Systems and Sensors in Physical Rehabilitation; and Assistive Systems.
22.9K
19 Feb 2021
Topic Review
MP3 Player
An MP3 player is an electronic device that can play MP3 digital audio files. It is a type of digital audio player (DAP), or portable media player. Most players play more than the MP3 file format, such as Windows Media Audio (WMA), Advanced Audio Coding (AAC), Vorbis, FLAC, Speex and Ogg.
22.5K
19 Oct 2022
Topic Review
TCP-based Congestion Control Algorithms
In today’s data networks, the main protocol used to ensure reliable communications is the transmission control protocol (TCP). The TCP performance is largely determined by the used congestion control (CC) algorithm, which main purpose is to avoid the congestion of the network that can be caused by a large burst of data traffic. TCP CC algorithms have evolved over the past three decades and a large number of CC algorithm variations have been developed to accommodate various communication network environments. Considering the importance of CC in communication networks, the fundamentals of the TCP as the main transport layer protocol and CC process have been explained in detail. Also, an encyclopedic overview of the most popular single-flow and multi-flow TCP CC algorithms with corresponding alternatives has been present. Future directions in the possible improvement of CC algorithms for implementation in complex heterogeneous networks composed of wired and wireless elements are lastly discussed in this encyclopedic work.
20.8K
21 Jul 2021
Topic Review
List of Qualcomm Snapdragon Systems-on-chip
This is a list of Qualcomm Snapdragon chips. Snapdragon is a family of mobile system on a chip (SoC) made by Qualcomm for use in smartphones, tablets, laptops, 2-in-1 PCs, smartwatches , and smartbooks devices.
20.5K
19 Oct 2022
Topic Review
Shaft Mining
Shaft mining or shaft sinking is excavating a vertical or near-vertical tunnel from the top down, where there is initially no access to the bottom. Shallow shafts, typically sunk for civil engineering projects differ greatly in execution method from deep shafts, typically sunk for mining projects. When the top of the excavation is the ground surface, it is referred to as a shaft; when the top of the excavation is underground, it is called a winze or a sub-shaft. Small shafts may be excavated upwards from within an existing mine as long as there is access at the bottom, in which case they are called Raises. A shaft may be either vertical or inclined (between 45 and 90 degrees to the horizontal), although most modern mine shafts are vertical. If access exists at the bottom of the proposed shaft and ground conditions allow then raise boring may be used to excavate the shaft from the bottom up, such shafts are called borehole shafts. Shaft sinking is one of the most difficult of all development methods: restricted space, gravity, groundwater and specialized procedures make the task quite formidable. Historically mine shaft sinking has been among the most dangerous of all the mining occupations and the preserve of mining contractors called sinkers. Today shaft sinking contractors are concentrated in Canada , Germany and South Africa .
20.2K
17 Nov 2022
Topic Review
History of VFX
The History of Visual Effects (VFX) is intertwined with that of cinematography, special effects, animation and computer-generated imagery.
20.0K
10 Oct 2022
Topic Review
Photovoltaic Cell Generations
Solar energy is one of the most demanding renewable sources of electricity. Electricity production using photovoltaic technology not only helps meet the growing demand for energy, but also contributes to mitigating global climate change by reducing dependence on fossil fuels. The level of competitiveness of innovative next-generation solar cells is increasing due to the efforts of researchers and scientists related to the development of new materials, particularly nanomaterials and nanotechnology.
19.1K
25 Aug 2022
Topic Review
EEG Power Spectrum
The electrical activity of the brain reflected in the electroencephalogram (EEG) is determined by neurons, glia cells, and the blood-brain barrier, which is mainly caused by nerve cells.
18.9K
30 Oct 2020
Topic Review
High Voltage Direct Current (HVDC) Technology
Two main high voltage direct current (HVDC) technologies: line-commutated converters (LCC), also known as current-source converters (CSC) using thyristors, and voltage-source converters (VSC)-HVDC, using IGBT transistors, both are suitable for a wide range of applications.
18.2K
07 Mar 2022
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