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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.
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  • 24 Nov 2022
Topic Review
Quote Notation
Quote notation is a representation of the rational numbers based on Kurt Hensel's p-adic numbers. In quote notation, arithmetic operations take particularly simple, consistent forms, producing exact answers with no roundoff error. Quote notation’s arithmetic algorithms work in a right-to-left direction; addition, subtraction, and multiplication algorithms are the same as for natural numbers, and division is easier than the usual division algorithm. The notation was invented by Eric Hehner of the University of Toronto and Nigel Horspool, then at McGill University, and published in the SIAM Journal on Computing, v.8, n.2, May 1979, pp. 124–134.
  • 1.4K
  • 24 Nov 2022
Topic Review
At-Large Advisory Committee
The At-Large Advisory Committee (ALAC) is an advisory committee to ICANN, the organization that administers the Internet's Domain Name System and addressing system. According to ICANN Bylaw XI.4.a, "ALAC is the primary organizational home within ICANN for individual Internet users", with a mandate to "consider and provide advice on the activities of ICANN, insofar as they relate to the interests of individual Internet users".
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  • 24 Nov 2022
Topic Review
Halemaʻumaʻu Crater
Halemaʻumaʻu Crater (six syllables: HAH-lay-MAH-oo-MAH-oo) is a pit crater located within the much larger summit caldera of Kīlauea in Hawaii Volcanoes National Park. The roughly circular crater was 770 meters (2,530 ft) x 900 m (2,950 ft) prior to collapses that roughly doubled the size of the crater after May 3, 2018. Halemaʻumaʻu is home to Pele, goddess of fire and volcanoes, according to the traditions of Hawaiian religion. Halemaʻumaʻu means "house of the ʻāmaʻu fern". The crater until recently contained an active lava lake. From 2008, when the current vent inside Halemaʻumaʻu crater first erupted, to April 2015, lava was present inside the vent, fluctuating from 20 to 150 meters below the crater rim. On April 24, 2015 molten lava in the vent, known as the Overlook Crater, became directly visible for the first time from the Jaggar Museum overlook at the Hawaiian Volcano Observatory, when the lava rose to an all-time high level since the Overlook Crater first opened. A few days later, on April 29, the lava started spilling over the rim of the Overlook Crater and onto the floor of Halemaʻumaʻu Crater, ultimately adding a layer of lava approximately 30 feet (9 m) thick to the crater floor. For three years from 2015 to 2018 the lava lake level remained close to the rim, with a further minor overflow event in October 2016 and a significant one in April 2018 that covered a majority of the crater floor in new lava. In early May 2018 the lava level in the Overlook Crater dropped over 700 feet and out of sight, resulting in explosions, earthquakes and large clouds of ash and toxic gas, causing closure of the Kīlauea summit area of the national park from May 10 to September 22. While the park visitor center and headquarters have reopened to the public, the crater is currently in a state of collapse that includes substantial portions of Kīlauea Caldera. The Jaggar Museum overlooking the crater remains closed.
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  • 24 Nov 2022
Topic Review
Benign Migratory Stomatitis
Geographic tongue, also known by several other terms,[note 1] is a condition of the mucous membrane of the tongue, usually on the dorsal surface. It is a common condition, affecting approximately 2–3% of the general population. It is characterized by areas of smooth, red depapillation (loss of lingual papillae) which migrate over time. The name comes from the map-like appearance of the tongue, with the patches resembling the islands of an archipelago. The cause is unknown, but the condition is entirely benign (importantly, it does not represent oral cancer), and there is no curative treatment. Uncommonly, geographic tongue may cause a burning sensation on the tongue, for which various treatments have been described with little formal evidence of efficacy.
  • 1.9K
  • 24 Nov 2022
Topic Review
Muhajir (Pakistani)
The Muhajir (Urdu: مہاجر‎, also spelled Mahajir and Mohajir) are Muslim immigrants, of multi-ethnic origin, and their descendants, who migrated from various regions of India after the Partition of India to settle in the newly independent state of Pakistan . The term Muhajirs refers to those Muslim migrants from India who mostly settled in urban Sindh.
  • 14.9K
  • 23 Jan 2024
Topic Review
Attacks on Humanitarian Workers
Humanitarian aid workers belonging to United Nations organisations, PVOs / NGOs or the Red Cross / Red Crescent have traditionally enjoyed both international legal protection, and de facto immunity from attack by belligerent parties. However, attacks on humanitarian workers have occasionally occurred, and became more frequent since the 1990s and 2000s. In 2017, the Aid Worker Security Database (AWSD) documented 139 humanitarian workers killed in intentional attacks out of the estimated global population of 569,700 workers. In every year since 2013, more than 100 humanitarian workers were killed. This is attributed to a number of factors, including the increasing number of humanitarian workers deployed, the increasingly unstable environments in which they work, and the erosion of the perception of neutrality and independence. In 2012 road travel was seen to be the most dangerous context, with kidnappings of aid workers quadrupling in the last decade, reaching more aid workers victims than any other form of attack. The foremost collector of data on attacks against humanitarian workers is the Aid Worker Security Database, which has strict parameters allowing for the data to be compared across the globe over time, producing useful analysis for the humanitarian, policy and academic community. Armed Conflict Location & Event Data Project (ACLED) is another database that includes attacks on humanitarian workers in addition to other conflict related incidents. Insecurity Insight produces monthly Aid in Danger reports that highlight attacks during the month from news media, the AWSD and ACLED.
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  • 24 Nov 2022
Topic Review
USS Aramis (SP-418)
USS Aramis (SP-418/PY-7) was a yacht acquired by the United States Navy during World War I which served as a patrol boat off New York City, was then fitted with an experimental "underwater detection system" and depth charges as an anti-submarine vessel, and was briefly the flagship of a battleship squadron. She ended her career as a tender and houseboat to a survey vessel off the coast of Cuba, until disposed of in 1933.
  • 606
  • 24 Nov 2022
Topic Review
Muntanya Assolada
Muntanya Assolada is a Bronze Age settlement located on the right bank of the Xúquer river, in Spain, built on the top of a spur of the Corbera mountain range, dominating the river plain from a height of 227 metres (745 ft) above sea level. It is located in the municipality of Alzira, Valencia, Spain. Excavation campaigns began in 1978, under the direction of Bernat Martí Oliver, and continued until 1996, and work on the site was resumed in 2004. From the 1990s Rosa Enguix Alemany and María Jesús de Pedro joined the direction of the site. At present the excavated area covers 700 square metres (7,500 sq ft) and includes different structures, like a central street and rectangular departments on both sides; a wall of two meters wide that preserves almost three meters of height (6.6 × 9.8 ft); occupancy soils and abandonment episodes; livestock stabling; and terracing of the slopes to expand its surface. At present the site is property of the Alzira City council, and the new beginning of the excavations by the Servei d'Investigació Prehistòrica has as objective the consolidation of the exhumed structures and its signposting for visitor access. A nearby burial cave indicates the continuity in the use of natural caves as necropolis, and an individual burial has been found in a pit in the interior of the area too. On the other hand, the recovered remains show a wide chronological sequence between the Early Bronze and the Late Bronze.
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  • 24 Nov 2022
Topic Review
Open Knowledge International
Open Knowledge International (OKI) (known as the Open Knowledge Foundation (OKF) until April 2014, then Open Knowledge until May 2016) is a global non-profit network that promotes and shares information at no charge, including both content and data. It was founded by Rufus Pollock on 24 May 2004 in Cambridge, UK.
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  • 24 Nov 2022
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