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🔗 Mathematics

In knot theory, Conway notation, invented by John Horton Conway, is a way of describing knots that makes many of their properties clear. It composes a knot using certain operations on tangles to construct it.

🔗 France 🔗 France/Paris 🔗 Psychology 🔗 Travel and Tourism

Paris syndrome (French: syndrome de Paris, Japanese: パリ症候群, pari shōkōgun) is a condition exhibited by some individuals when visiting or going on vacation to Paris, as a result of extreme shock at discovering that Paris is different from their expectations. The syndrome is characterized by a number of psychiatric symptoms such as acute delusional states, hallucinations, feelings of persecution (perceptions of being a victim of prejudice, aggression, or hostility from others), derealization, depersonalization, anxiety, and also psychosomatic manifestations such as dizziness, tachycardia, sweating, and others, such as vomiting. Similar syndromes include Jerusalem syndrome and Stendhal syndrome. The condition is commonly viewed as a severe form of culture shock. It is particularly noted among Japanese travellers. It is not listed as a recognised condition in the Diagnostic and Statistical Manual of Mental Disorders.

🔗 Computing 🔗 Mathematics

Wireworld is a cellular automaton first proposed by Brian Silverman in 1987, as part of his program Phantom Fish Tank. It subsequently became more widely known as a result of an article in the "Computer Recreations" column of Scientific American. Wireworld is particularly suited to simulating transistors, and Wireworld is Turing-complete.

🔗 Mathematics

Toom–Cook, sometimes known as Toom-3, named after Andrei Toom, who introduced the new algorithm with its low complexity, and Stephen Cook, who cleaned the description of it, is a multiplication algorithm for large integers.

Given two large integers, a and b, Toom–Cook splits up a and b into k smaller parts each of length l, and performs operations on the parts. As k grows, one may combine many of the multiplication sub-operations, thus reducing the overall complexity of the algorithm. The multiplication sub-operations can then be computed recursively using Toom–Cook multiplication again, and so on. Although the terms "Toom-3" and "Toom–Cook" are sometimes incorrectly used interchangeably, Toom-3 is only a single instance of the Toom–Cook algorithm, where k = 3.

Toom-3 reduces 9 multiplications to 5, and runs in Θ(n^{log(5)/log(3)}) ≈ Θ(n^1.46). In general, Toom-k runs in Θ(c(k) n^e), where e = log(2k − 1) / log(k), n^e is the time spent on sub-multiplications, and c is the time spent on additions and multiplication by small constants. The Karatsuba algorithm is a special case of Toom–Cook, where the number is split into two smaller ones. It reduces 4 multiplications to 3 and so operates at Θ(n^{log(3)/log(2)}) ≈ Θ(n^1.58). Ordinary long multiplication is equivalent to Toom-1, with complexity Θ(n²).

Although the exponent e can be set arbitrarily close to 1 by increasing k, the function c unfortunately grows very rapidly. The growth rate for mixed-level Toom–Cook schemes was still an open research problem in 2005. An implementation described by Donald Knuth achieves the time complexity Θ(n 2^{√2 log n} log n).

Due to its overhead, Toom–Cook is slower than long multiplication with small numbers, and it is therefore typically used for intermediate-size multiplications, before the asymptotically faster Schönhage–Strassen algorithm (with complexity Θ(n log n log log n)) becomes practical.

Toom first described this algorithm in 1963, and Cook published an improved (asymptotically equivalent) algorithm in his PhD thesis in 1966.

🔗 Mathematics 🔗 Cryptography 🔗 Cryptography/Computer science

TWINKLE (The Weizmann Institute Key Locating Engine) is a hypothetical integer factorization device described in 1999 by Adi Shamir and purported to be capable of factoring 512-bit integers. It is also a pun on the twinkling LEDs used in the device. Shamir estimated that the cost of TWINKLE could be as low as $5000 per unit with bulk production. TWINKLE has a successor named TWIRL which is more efficient.

🔗 United States 🔗 Biography 🔗 Women's History 🔗 Christianity 🔗 Gender Studies 🔗 United States/Rhode Island 🔗 Christianity/Religious Society of Friends (Quakers)

The Public Universal Friend (born Jemima Wilkinson; November 29, 1752 – July 1, 1819) was an American preacher born in Cumberland, Rhode Island, to Quaker parents. After suffering a severe illness in 1776, the Friend claimed to have died and been reanimated as a genderless evangelist named the Public Universal Friend, and afterward shunned both birth name and gendered pronouns. In androgynous clothes, the Friend preached throughout the northeastern United States, attracting many followers who became the Society of Universal Friends.

The Public Universal Friend's theology was broadly similar to that of most Quakers. The Friend stressed free will, opposed slavery, and supported sexual abstinence. The most committed members of the Society of Universal Friends were a group of unmarried women who took leading roles in their households and community. In the 1790s, members of the Society acquired land in Western New York where they formed the township of Jerusalem near Penn Yan, New York. The Society of Universal Friends ceased to exist by the 1860s. Many writers have portrayed the Friend as a woman, and either a manipulative fraudster, or a pioneer for women's rights; others have viewed the preacher as transgender or non-binary and a figure in trans history.

🔗 Biography 🔗 Military history 🔗 Military history/North American military history 🔗 Military history/United States military history 🔗 Women's History 🔗 Military history/Military biography 🔗 Military history/Early Modern warfare 🔗 Military history/American Revolutionary War 🔗 Biography/military biography 🔗 Military history/Intelligence

Agent 355 (died after 1780) was the code name of a female spy during the American Revolution, part of the Culper Ring. Agent 355 was one of the first spies for the United States, but her real identity is unknown. The number, 355, could be de-crypted from the system the Culper Ring used to mean "lady."

"Pierre Menard, Author of the Quixote" (original Spanish title: "Pierre Menard, autor del Quijote") is a short story by Argentine writer Jorge Luis Borges.

It originally appeared in Spanish in the Argentine journal Sur in May 1939. The Spanish-language original was first published in book form in Borges's 1941 collection El jardín de senderos que se bifurcan (The Garden of Forking Paths), which was included in his much-reprinted Ficciones (1944).

🔗 Central Asia 🔗 Mining 🔗 Central Asia/Turkmenistan 🔗 Turkmenistan

The Darvaza gas crater (Turkmen: Garagum ýalkymy), also known as the Door to Hell or Gates of Hell, or, officially, the Shining of Karakum, is a burning natural gas field collapsed into a cavern near Darvaza, Turkmenistan. The floor and especially rim of the crater is illumined by hundreds of natural gas fires. The crater has been burning for an unknown amount of time, as how the crater formed and ignited remains unknown.

🔗 Electronic music 🔗 Music/Music genres

Lowercase is an extreme form of ambientminimalism where very quiet, usually unheard sounds are amplified to extreme levels. Minimal artist Steve Roden popularized the movement with an album entitled Forms of Paper, in which he made recordings of himself handling paper in various ways. These recordings were commissioned by the Hollywood branch of the Los Angeles Public Library.