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πŸ”— Tommy Flowers

πŸ”— Biography πŸ”— London πŸ”— Biography/science and academia πŸ”— Engineering

Thomas Harold Flowers MBE (22 December 1905 - 28 October 1998) was an English engineer with the British General Post Office. During World War II, Flowers designed and built Colossus, the world's first programmable electronic computer, to help decipher encrypted German messages.

πŸ”— Secretary Problem

πŸ”— Mathematics πŸ”— Statistics

The secretary problem is a problem that demonstrates a scenario involving optimal stopping theory. The problem has been studied extensively in the fields of applied probability, statistics, and decision theory. It is also known as the marriage problem, the sultan's dowry problem, the fussy suitor problem, the googol game, and the best choice problem.

The basic form of the problem is the following: imagine an administrator who wants to hire the best secretary out of n {\displaystyle n} rankable applicants for a position. The applicants are interviewed one by one in random order. A decision about each particular applicant is to be made immediately after the interview. Once rejected, an applicant cannot be recalled. During the interview, the administrator gains information sufficient to rank the applicant among all applicants interviewed so far, but is unaware of the quality of yet unseen applicants. The question is about the optimal strategy (stopping rule) to maximize the probability of selecting the best applicant. If the decision can be deferred to the end, this can be solved by the simple maximum selection algorithm of tracking the running maximum (and who achieved it), and selecting the overall maximum at the end. The difficulty is that the decision must be made immediately.

The shortest rigorous proof known so far is provided by the odds algorithm (Bruss 2000). It implies that the optimal win probability is always at least 1 / e {\displaystyle 1/e} (where e is the base of the natural logarithm), and that the latter holds even in a much greater generality (2003). The optimal stopping rule prescribes always rejecting the first ∼ n / e {\displaystyle \sim n/e} applicants that are interviewed and then stopping at the first applicant who is better than every applicant interviewed so far (or continuing to the last applicant if this never occurs). Sometimes this strategy is called the 1 / e {\displaystyle 1/e} stopping rule, because the probability of stopping at the best applicant with this strategy is about 1 / e {\displaystyle 1/e} already for moderate values of n {\displaystyle n} . One reason why the secretary problem has received so much attention is that the optimal policy for the problem (the stopping rule) is simple and selects the single best candidate about 37% of the time, irrespective of whether there are 100 or 100 million applicants.

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πŸ”— Kwangmyong, the North-Korea-Wide-Web

πŸ”— Mass surveillance πŸ”— Computing πŸ”— Korea πŸ”— Korea/North Korea

Kwangmyong (literally β€œBright Light”) is a North Korean "walled garden" national intranet service opened in 2000.

The network uses domain names under the .kp top level domain that are not accessible from the global Internet. As of 2016 the network uses IPv4 addresses reserved for private networks in the 10.0.0.0/8 range. North Koreans often find it more convenient to access sites by their IP address rather than by URL using Latin characters. Like the global Internet, the network hosts content accessible with web browsers, and provides an internal web search engine. It also provides email services and news groups.

Only foreigners and a small number of government officials/scholars/elites are allowed to use the global Internet in North Korea, making Kwangmyong the only computer network available to most North Korean citizens. It is a free service for public use.

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πŸ”— The Jakarta Incident, or Rebooting 747 Engines In Flight

πŸ”— Aviation πŸ”— Disaster management πŸ”— Aviation/Aviation accident πŸ”— United Kingdom πŸ”— Indonesia

British Airways Flight 9, sometimes referred to by its callsign Speedbird 9 or as the Jakarta incident, was a scheduled British Airways flight from London Heathrow to Auckland, with stops in Bombay, Kuala Lumpur, Perth, and Melbourne.

On 24 June 1982, the route was flown by the City of Edinburgh, a Boeing 747-200. The aircraft flew into a cloud of volcanic ash thrown up by the eruption of Mount Galunggung (approximately 110 miles (180Β km) south-east of Jakarta, Indonesia), resulting in the failure of all four engines. The reason for the failure was not immediately apparent to the crew or air traffic control. The aircraft was diverted to Jakarta in the hope that enough engines could be restarted to allow it to land there. The aircraft glided out of the ash cloud, and all engines were restarted (although one failed again soon after), allowing the aircraft to land safely at the Halim Perdanakusuma Airport in Jakarta.

The crew members of the accident segment had boarded the aircraft in Kuala Lumpur, while many of the passengers had been aboard since the flight began in London.

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πŸ”— Golden hat

πŸ”— Germany πŸ”— Time πŸ”— Archaeology πŸ”— Visual arts πŸ”— Fashion

Golden hats (or Gold hats) (German: GoldhΓΌte, singular: Goldhut) are a very specific and rare type of archaeological artifact from Bronze Age Europe. So far, four such objects ("cone-shaped gold hats of the Schifferstadt type") are known. The objects are made of thin sheet gold and were attached externally to long conical and brimmed headdresses which were probably made of some organic material and served to stabilise the external gold leaf. The following Golden Hats are known as of 2012:

  • Golden Hat of Schifferstadt, found in 1835 at Schifferstadt near Speyer, c. 1400–1300 BC.
  • Avanton Gold Cone, incomplete, found at Avanton near Poitiers in 1844, c. 1000–900 BC.
  • Golden Cone of Ezelsdorf-Buch, found near Ezelsdorf near Nuremberg in 1953, c. 1000–900 BC; the tallest known specimen at c. 90Β cm.
  • Berlin Gold Hat, found probably in Swabia or Switzerland, c. 1000–800 BC; acquired by the Museum fΓΌr Vor- und FrΓΌhgeschichte, Berlin, in 1996.

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πŸ”— Capitol Hill's mystery soda machine

πŸ”— United States πŸ”— United States/Washington - Seattle πŸ”— United States/Washington

Capitol Hill's mystery soda machine was a Coke vending machine in Capitol Hill, Seattle, that was in operation since at least the early 1990s until its disappearance in 2018. It is unknown who stocked the machine.

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πŸ”— Autopen

πŸ”— Technology πŸ”— Writing

An autopen or signing machine is a device used for the automatic signing of a signature or autograph. Many celebrities, politicians and public figures receive hundreds of letters a day, many of which request a personal reply; this leads to a situation in which either the individual must artificially reproduce their signature or heavily limit the number of recipients who receive a personal response. Given the exact verisimilitude to the real hand signature, the use of the autopen allows for a small degree of wishful thinking and plausible deniability as to whether a famous autograph is real or reproduced, thus increasing the perception of the personal value of the signature by the lay recipient. However, known or suspected autopen signatures are also vastly less valuable as philographic collectibles; legitimate hand-signed documents from individuals known to also use an autopen usually require verification and provenance to be considered valid.

The early autopens used a plastic matrix of the original signature which is a channel cut into an engraved plate in the shape of a wheel. A stylus driven by an electric motor followed the x and y axis of a profile or shape engraved in the plate (which is why it is called a matrix). The stylus is mechanically connected to an arm which can hold almost any common writing instrument, so the favourite pen and ink can be used to suggest authenticity. The Autopen signature is made with even pressure (and indentation in the paper), which is how these machines are distinguishable from original handwriting where the pressure varies.

Modern day autopens use a signature smart card or USB flash drive to store signatures and phrases instead of the plastic matrices. In addition, certain models can replicate entire pages of writing once a custom font has been created in a user's handwriting.

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πŸ”— How to get bias into a Wikipedia article

Tilt! How to get bias into a Wikipedia article

To all you budding propagandists in Wikiland: too many of you are working like a bunch of amateurs. Sorry to be so negative, but you have to understand that getting bias into the Wikipedia is a skill; it requires practice, finesse and imagination. It has to be learned; it is not a natural thing, though some have more talent for it than others.

I have been following the Middle East Wikipedia battleground for a few years now, and have been very impressed with the skill of some editors in introducing bias into articles. To ingenuous editors, some of these techniques may seem innocuous enough; in many cases, it is hard to see how proposed edits are biasing an article one way or another. It is, in fact, only in the last few months that I have been able to define what these techniques are and how they work to introduce bias.

The first thing you need to know as a budding propagandist is this: there are two levels at which bias is introduced into the Wikipedia: at the article level, and at the topic level. You need to set your sights high: you don't want to merely bias a single article, you want the entire Wikipedia on your side. Without understanding the importance of topic bias, it is hard to understand many of the article-level techniques, so I will start with the topic level.

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πŸ”— List of Hoaxes on Wikipedia

πŸ”— Lists πŸ”— Skepticism πŸ”— Counter-Vandalism Unit

This is a list of known historical hoaxes on Wikipedia. Its purpose is to document hoaxes on Wikipedia, in order to improve our understanding of them and our ability to detect them. For the purpose of this list, a hoax is defined as a clear and deliberate attempt to deceptively present false information as fact. Libel, vandalism, and honest factual errors are not considered hoaxes. A hoax is considered notable enough for inclusion in this list if it evaded detection for more than one month or was discussed by reliable sources in the media. This list is incomplete, as many hoaxes remain undiscovered.

Hoaxes can be added to this page if they meet the requirements above. Do not list Wikipedia April Fools' Day pranks or factual articles about encyclopedically notable hoaxes. Start/Deletion date and Length are the dates and approximate time the article was generally visible.

For many of the below hoaxes, you can see an archived version of the deleted article by clicking on its title (see also list of archived hoaxes). Some also remain available from mirror sites. Any administrator can create an archived version of a hoax upon request by following the instructions below.

Academic research has investigated the impact and characteristics of Wikipedia hoaxes, and has proposed automated methods for detecting them. Researchers found that the automatic classification system was better at identifying hoaxes on Wikipedia than humans (86% vs. 63% accuracy) and used their algorithm to identify previously undiscovered hoaxes like "Steve Moertel" which went undetected for almost 7 years.

One way to identify hoax articles included examining the article structure and content, its mentions in other articles on Wikipedia (i.e., embeddedness), and features of the editor who created the page. Specifically, hoax articles are likely to be longer than a legitimate article, less likely to have links to other Wikipedia articles, references, images, or other "wiki-like" markup, less likely to be mentioned in other Wikipedia articles before its creation, and more likely to be created by a new account with few to no other edits.

While most hoaxes on Wikipedia are short-lived (90% of discovered hoaxes are flagged within one hour of creation and only 1% of hoaxes persist for more than a year), those that make it past this initial screening have an increased probability of continuing to "survive" and remain a part of Wikipedia for much longer (if a hoax survives past its first day, it has an 18% probability of lasting for a year or more). Compared to unsuccessful hoaxes, successful hoaxes that survive for long periods of time are more likely to include some "wiki-like" mark-up and more likely to include links to other articles on Wikipedia.

Compared to legitimate articles, successful hoaxes generally receive less daily traffic, have a longer median article length (134 vs. 71 words), and include fewer links to other Wikipedia articles when considering their article length.

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πŸ”— Celtuce

πŸ”— China πŸ”— Food and drink πŸ”— Plants πŸ”— Taiwan πŸ”— Project-independent assessment

Celtuce () (Lactuca sativa var. augustana, angustata, or asparagina), also called stem lettuce, celery lettuce, asparagus lettuce, or Chinese lettuce, is a cultivar of lettuce grown primarily for its thick stem or its leaves, which are known as A-choy. It is used as a vegetable. In China, the family is informally called woju (traditional Chinese: 萡苣; simplified Chinese: θŽ΄θ‹£; pinyin: wōjΓΉ), which is also the name of a cultivar. It is especially popular in both China and Taiwan, where the stem is interchangeably called wosun (traditional Chinese: 萡筍; simplified Chinese: θŽ΄η¬‹; pinyin: wōsΗ”n) or qingsun(青筍; 青笋; qΔ«ngsΗ”n).

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