Random Articles (Page 2)
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π Johns Hopkins Beast
The Johns Hopkins Beast was a mobile automaton, an early pre-robot, built in the 1960s at the Johns Hopkins University Applied Physics Laboratory. The machine had a rudimentary intelligence and the ability to survive on its own. As it wandered through the white halls of the laboratory, it would seek black wall outlets. When it found one it would plug in and recharge.
The robot was cybernetic. It did not use a computer. Its control circuitry consisted of dozens of transistors controlling analog voltages. It used photocell optics and sonar to navigate. The 2N404 transistors were used to create NOR logic gates that implemented the Boolean logic to tell it what to do when a specific sensor was activated. The 2N404 transistors were also used to create timing gates to tell it how long to do something. 2N1040 Power transistors were used to control the power to the motion treads, the boom, and the charging mechanism.
The original sensors in Mod I were physical touch only. The wall socket was detected by physical switches on the arm that followed the wall. Once detected, two electrical prongs were extended until they entered the wall socket and made the electrical connection to charge the vehicle. The stairway, doors, and pipes on the hall wall were also detected by physical switches and recognized by appropriate logic.
The sonar guidance system was developed for Mod I and improved for Mod II. It used two ultrasonic transducers to determine distance, location within the halls, and obstructions in its path. This provided "The Beast" with bat-like guidance. At this point, it could detect obstructions in the hallway, such as people in the hallway. Once an obstruction was detected, the Beast would slow down and then decide whether to stop or divert around the obstruction. It could also ultrasonically recognize the stairway and doorways to take appropriate action.
An optical guidance system was added to Mod II. This provided, among other capabilities, the ability to optically identify the black wall sockets that contrasted with the white wall.
The Hopkins Beast Autonomous Robot Mod II link below was written by Dr. Ronald McConnell, at that time a co-op student and one of the designers for Mod II.
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- "Johns Hopkins Beast" | 2022-03-30 | 198 Upvotes 48 Comments
π Ghoti
Ghoti is a creative respelling of the word fish, used to illustrate irregularities in English spelling and pronunciation.
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- "Ghoti" | 2020-06-20 | 317 Upvotes 239 Comments
π Lithophone
A lithophone is a musical instrument consisting of a rock or pieces of rock which are struck to produce musical notes. Notes may be sounded in combination (producing harmony) or in succession (melody). The lithophone is an idiophone comparable to instruments such as the glockenspiel, vibraphone, xylophone and marimba.
In the Hornbostel-Sachs classification system, lithophones are designated as '111.22' β directly-struck percussion plaques.
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- "Lithophone" | 2020-02-22 | 54 Upvotes 7 Comments
π Assassination of Kim Jong-Nam
On 13 February 2017, the eldest son of Kim Jong-il and half-brother of Kim Jong-un, Kim Jong-nam, was attacked with the nerve agent VX at Kuala Lumpur International Airport in Malaysia. He had been exiled from North Korea in 2003 and had been living abroad.
Following his visit to the resort island Langkawi, Kim Jong-nam had arrived at terminal 2 sometime before 9:00 a.m. to take a 10:50 a.m. AirAsia flight to Macau. At approximately 9:00 a.m., two women attacked Kim Jong-nam with the VX nerve agent. He died about 15 to 20 minutes later.
The women were identified as Siti Aisyah, an Indonesian and ΔoΓ n Thα» HΖ°Ζ‘ng, a Vietnamese. Both were charged with the murder of Kim Jong-nam. The charges were dropped, although HΖ°Ζ‘ng pled guilty to "voluntarily causing hurt by dangerous weapons or means" and received a sentence of three years and four months. Four North Korean suspects left the airport shortly after the assassination and reached Pyongyang without being arrested. Other North Koreans were arrested but were released without charge.
It is widely believed that Kim Jong-nam was murdered on the orders of Kim Jong-un.
π Eichmann in Jerusalem: A Report on the Banality of Evil
Eichmann in Jerusalem: A Report on the Banality of Evil is a 1963 book by political thinker Hannah Arendt. Arendt, a Jew who fled Germany during Adolf Hitler's rise to power, reported on the trial of Adolf Eichmann, one of the major organizers of the Holocaust, for The New Yorker. A revised and enlarged edition was published in 1964.
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- "Eichmann in Jerusalem: A Report on the Banality of Evil" | 2023-11-15 | 30 Upvotes 6 Comments
π List Of Adhesive Tapes
The following is a list of adhesive tapes with pressure-sensitive adhesives:
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- "List Of Adhesive Tapes" | 2022-04-15 | 162 Upvotes 135 Comments
π Distributism
Distributism is an economic theory asserting that the world's productive assets should be widely owned rather than concentrated.
Developed in Europe in the late 19th and early 20th centuries, distributism was based upon the principles of Catholic social teaching, especially the teachings of Pope Leo XIII in his encyclical Rerum novarum (1891) and Pope Pius XI in Quadragesimo anno (1931). It views both capitalism and socialism as equally flawed and exploitative, and it favors economic mechanisms such as cooperatives and member-owned mutual organizations as well as small businesses, and large-scale antitrust regulations.
Some Christian democratic political parties have advocated distributism in their economic policies.
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- "Distributism" | 2019-04-01 | 209 Upvotes 113 Comments
π Museum Fatigue
Museum fatigue is a state of physical or mental fatigue caused by the experience of exhibits in museums and similar cultural institutions. The collection of phenomena that characterize museum fatigue was first described in 1916, and has since received widespread attention in popular and scientific contexts.
The first known description of museum fatigue was made by Benjamin Ives Gilman in the January 1916 edition of The Scientific Monthly. Gilman mainly focused on the efforts of museum fatigue on how the viewing displays are placed. Gilman went on to say that the way the displays were presented caused museum fatigue. In other later studies, Edward Robinson in 1928 spoke more about museum fatigue, specifically of four museums that showed a lot of characteristics of museum fatigue because of how the displays were placed. Arthur Melton provided more proof for Robinson by observing visitors' interest in the displays decreased as the number of displays increased.
In a more recent study of the phenomenon, Falk, Koran, Direking, and Dreblow studied museum fatigue at the Florida Museum of Natural History in 1985. While observing visitors they noticed a pattern of high interest in anything in the museum for about 30 minutes and then a decrease in interest. In 1997β1998, Beverly Serrell in her research determined that in less than 20 minutes people became apathetic towards the museum. Museum fatigue has also been applied in zoos to see if they had the same effect. In one study in 1986, Bitgood, Patterson, and Benefeld observed the reptile house of the Birmingham Zoo. While observing they noticed that the pattern was different from museum fatigue.
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- "Museum Fatigue" | 2024-07-16 | 51 Upvotes 21 Comments
π Parsons code
The Parsons code, formally named the Parsons code for melodic contours, is a simple notation used to identify a piece of music through melodic motion β movements of the pitch up and down. Denys Parsons developed this system for his 1975 book The Directory of Tunes and Musical Themes. Representing a melody in this manner makes it easier to index or search for pieces, particularly when the notes values are unknown.
The book was also published in Germany in 2002 and reprinted by Piatkus as The Directory of Classical Themes in 2008.
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- "Parsons code" | 2017-12-06 | 85 Upvotes 22 Comments