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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. 
  • 20.4K
  • 21 Jul 2021
Topic Review
History of VFX
The History of Visual Effects (VFX) is intertwined with that of cinematography, special effects, animation and computer-generated imagery.
  • 19.5K
  • 10 Oct 2022
Topic Review
Antenna Aperture
In electromagnetics and antenna theory, antenna aperture, effective area, or receiving cross section, is a measure of how effective an antenna is at receiving the power of electromagnetic radiation (such as radio waves). The aperture is defined as the area, oriented perpendicular to the direction of an incoming electromagnetic wave, which would intercept the same amount of power from that wave as is produced by the antenna receiving it. Assume a plane wave in a particular direction has an irradiance or power flux density [math]\displaystyle{ S }[/math]; this is the amount of power passing through a unit area of one square meter. Then if an antenna delivers [math]\displaystyle{ P_o }[/math] watts to the load connected to its output terminals (e.g. the receiver) when irradiated by a uniform field of power density [math]\displaystyle{ S }[/math] watts per square meter, the antenna's aperture for the direction of that plane wave is [math]\displaystyle{ A_e }[/math] in square meters, given by: So the power received by an antenna (in watts) is equal to the power density of the electromagnetic energy (in watts per square meter), multiplied by its aperture (in square meters). Radio waves from a direction where the antenna's aperture is larger thus collect a greater amount of that wave's power; this is more often referred to as antenna gain. To actually obtain that available power [math]\displaystyle{ P_o }[/math], the incoming radiation must be in the state of polarization specified for that antenna, and the load (receiver) must be impedance matched to the antenna's feedpoint impedance. The meaning of aperture is thus based on a receiving antenna, however any receiving antenna can also be used for transmission. Due to reciprocity, an antenna's gain in receiving and transmitting are identical, so the power transmitted by an antenna in different directions (the radiation pattern) is always proportional to the effective area [math]\displaystyle{ A_e }[/math] in each direction; that proportionality factor is derived below. When no direction is specified, [math]\displaystyle{ A_e }[/math] (or "antenna gain") is understood to refer to its maximum value, that is, in the intended direction(s) that the antenna is designed to receive from and/or transmit toward.
  • 8.7K
  • 27 Oct 2022
Topic Review
Broadcast Programming
Television scheduling strategies are employed to give programs the best possible chance of attracting and retaining an audience. They are used to deliver programs to audiences when they are most likely to want to watch them and deliver audiences to advertisers in the composition that makes their advertising most likely to be effective. Digitally based broadcast programming mechanisms are known as electronic program guides (EPG). At a micro level, scheduling is the minute planning of the transmission; what to broadcast and when, ensuring an adequate or maximum utilization of airtime.
  • 8.5K
  • 28 Nov 2022
Topic Review
Gaming Computer
A gaming computer, also known as a gaming PC, is a specialized personal computer designed for playing video games. Gaming PCs typically differ from mainstream personal computers by using high-performance video cards and high core-count central processing units with raw performance. Gaming PCs are also used for other demanding tasks such as video editing. Many gamers and computer enthusiasts choose to overclock their CPU(s) and GPU(s) in order to gain extra performance. The added power draw needed to overclock either processing unit often requires additional cooling, using upgraded air cooling or water cooling.
  • 8.3K
  • 01 Nov 2022
Topic Review
Optical Phase Shifters
Optical phase shifters have the functionality to control the phase of light by a change in the effective refractive index. In a Si photonics platform, it is an essential part composing optical modulators as well as switches in Si photonics. The realization of a silicon optical phase shifter marked a cornerstone for the development of silicon photonics, and it is expected that optical interconnects based on the technology relax the explosive datacom growth in data centers. High-performance silicon optical modulators and switches, integrated into a chip, play a very important role in optical transceivers, encoding electrical signals onto the light at high speed and routing the optical signals, respectively. The development of the devices is continuously required to meet the ever-increasing data traffic at higher performance and lower cost.
  • 7.3K
  • 08 Jun 2021
Topic Review
VDM-1
The Processor Technology VDM-1, for Video Display Module, was the first video card for S-100 bus computers. Created in 1975, it allows an S-100 machine to produce its own display, and when paired with a keyboard and their 3P+S card, it eliminates the need for a separate video terminal. Using a 7 x 9 dot matrix and ASCII characters, it produces a 64-column by 16-row text display. The VDM-1 is a complex card and was soon replaced by an increasing number of similar products from other companies. An early competitor was the Solid State Music VB-1, which offers an identical display from a much simpler card. Later cards using LSI chips have enough room to include the keyboard controller as well.
  • 7.2K
  • 08 Oct 2022
Topic Review
Softmod
A softmod is a method of using software to modify the intended behavior of hardware, such as video cards, sound cards, or game consoles in a way that can overcome restrictions of the firmware, or install custom firmware.
  • 6.3K
  • 23 Nov 2022
Topic Review
The Intelligent Reflecting Surface
The Intelligent Reflecting Surface (IRS) is a revolutionary technology to improve the performance of wireless data transmission systems. In particular, the wireless signal transmission environment is reconfigured by jointly adjusting a large number of small reflective units
  • 5.5K
  • 08 Apr 2022
Topic Review
Broadcasting of Sports Events
The broadcasting of sports events (also known as a sportscast) is the live coverage of sports as a television program, on radio, and other broadcasting media. It usually involves one or more sports commentators describing events as they happen.
  • 5.2K
  • 01 Dec 2022
Topic Review
Broadcasting
Broadcasting is the distribution of audio or video content to a dispersed audience via any electronic mass communications medium, but typically one using the electromagnetic spectrum (radio waves), in a one-to-many model. Broadcasting began with AM radio, which came into popular use around 1920 with the spread of vacuum tube radio transmitters and receivers. Before this, all forms of electronic communication (early radio, telephone, and telegraph) were one-to-one, with the message intended for a single recipient. The term broadcasting evolved from its use as the agricultural method of sowing seeds in a field by casting them broadly about. It was later adopted for describing the widespread distribution of information by printed materials or by telegraph. Examples applying it to "one-to-many" radio transmissions of an individual station to multiple listeners appeared as early as 1898. Over the air broadcasting is usually associated with radio and television, though more recently, both radio and television transmissions have begun to be distributed by cable (cable television). The receiving parties may include the general public or a relatively small subset; the point is that anyone with the appropriate receiving technology and equipment (e.g., a radio or television set) can receive the signal. The field of broadcasting includes both government-managed services such as public radio, community radio and public television, and private commercial radio and commercial television. The U.S. Code of Federal Regulations, title 47, part 97 defines "broadcasting" as "transmissions intended for reception by the general public, either direct or relayed". Private or two-way telecommunications transmissions do not qualify under this definition. For example, amateur ("ham") and citizens band (CB) radio operators are not allowed to broadcast. As defined, "transmitting" and "broadcasting" are not the same. Transmission of radio and television programs from a radio or television station to home receivers by radio waves is referred to as "over the air" (OTA) or terrestrial broadcasting and in most countries requires a broadcasting license. Transmissions using a wire or cable, like cable television (which also retransmits OTA stations with their consent), are also considered broadcasts but do not necessarily require a license (though in some countries, a license is required). In the 2000s, transmissions of television and radio programs via streaming digital technology have increasingly been referred to as broadcasting as well.
  • 4.6K
  • 24 Nov 2022
Topic Review
CubeSat Missions and Their Antenna Designs
CubeSats are a class of miniaturized satellites that have become increasingly popular in academia and among hobbyists due to their short development time and low fabrication cost. Their compact size, lightweight characteristics, and ability to form a swarm enables them to communicate directly with one another to inspire new ideas on space exploration, space-based measurements, and implementation of the latest technology. CubeSat missions require specific antenna designs in order to achieve optimal performance and ensure mission success. Over the past, a plethora of antenna designs have been proposed and implemented on CubeSat missions. Several challenges arise when designing CubeSat antennas such as gain, polarization, frequency selection, pointing accuracy, coverage, and deployment mechanisms.
  • 3.7K
  • 18 Jul 2022
Topic Review
IPTV
Internet Protocol television (IPTV) is the delivery of television content over Internet Protocol (IP) networks. This is in contrast to delivery through traditional terrestrial, satellite, and cable television formats. Unlike downloaded media, IPTV offers the ability to stream the source media continuously. As a result, a client media player can begin playing the content (such as a TV channel) almost immediately. This is known as streaming media. Although IPTV uses the Internet protocol it is not limited to television streamed from the Internet, (Internet television). IPTV is widely deployed in subscriber-based telecommunications networks with high-speed access channels into end-user premises via set-top boxes or other customer-premises equipment. IPTV is also used for media delivery around corporate and private networks. IPTV in the telecommunications arena is notable for its ongoing standardisation process (e.g., European Telecommunications Standards Institute). IPTV services may be classified into three main groups:  Live television and live media, with or without related interactivity; Time-shifted media: e.g. catch-up TV (replays a TV show that was broadcast hours or days ago), start-over TV (replays the current TV show from its beginning); Video on demand (VOD): browse and view items in a stored media catalogue.
  • 3.2K
  • 27 Oct 2022
Topic Review
GeForce 4 Series
The GeForce 4 series (codenames below) refers to the fourth generation of GeForce-branded graphics processing units (GPUs) manufactured by Nvidia. There are two different GeForce4 families, the high-performance Ti family, and the budget MX family. The MX family spawned a mostly identical GeForce4 Go (NV17M) family for the laptop market. All three families were announced in early 2002; members within each family were differentiated by core and memory clock speeds. In late 2002, there was an attempt to form a fourth family, also for the laptop market, the only member of it being the GeForce4 4200 Go (NV28M) which was derived from the Ti line.
  • 3.1K
  • 21 Oct 2022
Topic Review
35 Mm Film
35 mm film (millimeter) is the film gauge most commonly used for motion pictures and chemical still photography (see 135 film). The name of the gauge refers to the width of the photographic film, which consists of strips 34.98 ±0.03 mm (1.377 ±0.001 inches) wide. The standard negative pulldown for movies ("single-frame" format) is four perforations per frame along both edges, which results in 16 frames per foot of film. For still photography, the standard frame has eight perforations on each side. A variety of largely proprietary gauges were devised for the numerous camera and projection systems being developed independently in the late 19th century and early 20th century, ranging from 13 to 75 mm (0.51 to 2.95 in), as well as a variety of film feeding systems. This resulted in cameras, projectors, and other equipment having to be calibrated to each gauge. The 35 mm width, originally specified as ​1 3⁄8 inches, was introduced in 1892 by William Dickson and Thomas Edison, using 120 film stock supplied by George Eastman. Film 35 mm wide with four perforations per frame became accepted as the international standard gauge in 1909, and remained by far the dominant film gauge for image origination and projection until the advent of digital photography and cinematography, despite challenges from smaller and larger gauges, because its size allowed for a relatively good trade-off between the cost of the film stock and the quality of the images captured. The gauge has been versatile in application. It has been modified to include sound, redesigned to create a safer film base, formulated to capture color, has accommodated a bevy of widescreen formats, and has incorporated digital sound data into nearly all of its non-frame areas. Eastman Kodak, Fujifilm and Agfa-Gevaert are some companies that offered 35 mm films. Today Kodak is the last remaining manufacturer of motion picture film. The ubiquity of 35 mm movie projectors in commercial movie theaters made 35 mm the only motion picture format that could be played in almost any cinema in the world, until digital projection largely superseded it in the 21st century. It is difficult to compare the quality of film to digital media, but a good estimate would be about 33.6 megapixels (67.2 megapixels DSLR Bayer equivalent) would equal one 35-millimeter high quality color frame of film.
  • 3.1K
  • 18 Oct 2022
Topic Review
Over the Shoulder Shot
The over the shoulder shot (OTS) is a camera angle used in film and television, where the camera is placed above the back of the shoulder and head of a subject. This shot is most commonly used to present conversational back and forth between two subjects. With the camera placed behind one character, the shot then frames the sequence from the perspective of that character. The over the shoulder shot is then utilised in a shot-reverse-shot sequence where both subject's OTS perspectives are edited consecutively to create a back and forth interplay, capturing dialogue and reactions. This inclusion of the back of the shoulder allows audiences to understand the spatial relationships between two subjects, while still being able to capture a closer shot of each subject’s facial expression. In film and television, the filmmaker or cinematographer’s choice of an OTS shot’s camera height, the use of focus and lenses affect the way audiences interpret subjects and their relationships to others and space.
  • 3.1K
  • 02 Dec 2022
Topic Review
Nielsen Ratings
Nielsen TV ratings (commonly referred to as "Nielsen ratings") are the audience measurement systems operated by Nielsen Media Research that seek to determine the audience size and composition of television programming in the United States using a rating system. Nielsen Media Research was founded by Arthur C. Nielsen, a market analyst who started his career in the 1920s with marketing research and performance analysis. The company expanded into radio market analysis in the late 1930s, culminating in the Nielsen Radio Index in 1942, which was meant to provide statistics as to the markets of radio shows. The first Nielsen ratings for radio programs were released the first week of December 1947. They measured the top 20 programs in four areas: total audience, average audience, cumulative audience, and homes per dollar spent for time and talent. In 1950, Nielsen moved to television, developing a ratings system using the methods he and his company had developed for radio. That method became the primary source of audience measurement information in the US television industry.
  • 2.9K
  • 29 Sep 2022
Topic Review
Cinéma Pur
Cinéma Pur (French for "Pure Cinema") was an avant-garde film movement begun by filmmakers, like René Clair, who "wanted to return the medium to its elemental origins" of "vision and movement."
  • 2.9K
  • 09 Nov 2022
Topic Review
Drone Detection and Defense Systems
Drones are small and low-cost unmanned aerial vehicles (UAVs). With the decrease in the cost and size of drones in recent years, their number has also increased exponentially. As such, the concerns regarding security aspects that are raised by their presence are also becoming more serious.
  • 2.8K
  • 10 Mar 2022
Topic Review
GeForce 700 Series
The GeForce 700 series (stylized as GEFORCE GTX 700 SERIES) is a series of graphics processing units developed by Nvidia. While mainly a refresh of the Kepler microarchitecture (GK-codenamed chips), some cards use Fermi (GF) and later cards use Maxwell (GM). GeForce 700 series cards were first released in 2013, starting with the release of the GeForce GTX Titan on February 19, 2013, followed by the GeForce GTX 780 on May 23, 2013. The first mobile GeForce 700 series chips were released in April 2013.
  • 2.4K
  • 17 Oct 2022
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