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๐Ÿ”— Chernoff face

๐Ÿ”— Mathematics ๐Ÿ”— Statistics

Chernoff faces, invented by Herman Chernoff in 1973, display multivariate data in the shape of a human face. The individual parts, such as eyes, ears, mouth and nose represent values of the variables by their shape, size, placement and orientation. The idea behind using faces is that humans easily recognize faces and notice small changes without difficulty. Chernoff faces handle each variable differently. Because the features of the faces vary in perceived importance, the way in which variables are mapped to the features should be carefully chosen (e.g. eye size and eyebrow-slant have been found to carry significant weight).

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๐Ÿ”— The Scottish Play

๐Ÿ”— Scotland ๐Ÿ”— Theatre ๐Ÿ”— Shakespeare

The Scottish play and the Bard's play are euphemisms for William Shakespeare's Macbeth. The first is a reference to the play's Scottish setting, the second a reference to Shakespeareโ€™s popular nickname. According to a theatrical superstition, called the Scottish curse, speaking the name Macbeth inside a theatre, other than as called for in the script while rehearsing or performing, will cause disaster. A variation of the superstition also forbids quoting lines from the play within a theatre except as part of an actual rehearsal or performance of the play.

Because of this superstition, the lead character is often referred to as the Scottish King or Scottish Lord. Lady Macbeth is often referred to as the Scottish Lady. Sometimes Mackers or MacB is used to avoid saying the name.

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๐Ÿ”— Boustrophedon

๐Ÿ”— Greece ๐Ÿ”— Writing systems

Boustrophedon (Ancient Greek: ฮฒฮฟฯ…ฯƒฯ„ฯฮฟฯ†ฮทฮดฯŒฮฝ, boustrophฤ“dรณn "ox-turning" from ฮฒฮฟแฟฆฯ‚, bous, "ox", ฯƒฯ„ฯฮฟฯ†ฮฎ, strophฤ“, "turn" and the adverbial suffix -ฮดฯŒฮฝ, "like, in the manner of"; that is, turning like oxen in ploughing) is a type of bi-directional text, mostly seen in ancient manuscripts and other inscriptions. Alternate lines of writing are flipped, or reversed, with reversed letters. Rather than going left-to-right as in modern European languages, or right-to-left as in Arabic and Hebrew, alternate lines in boustrophedon must be read in opposite directions. Also, the individual characters are reversed, or mirrored. It was a common way of writing in stone in Ancient Greece.

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๐Ÿ”— Conway's Law

๐Ÿ”— Computing ๐Ÿ”— Systems ๐Ÿ”— Computing/Software ๐Ÿ”— Computing/Computer science ๐Ÿ”— Systems/Systems engineering

Conway's law is an adage stating that organizations design systems that mirror their own communication structure. It is named after computer programmer Melvin Conway, who introduced the idea in 1967. His original wording was:

Any organization that designs a system (defined broadly) will produce a design whose structure is a copy of the organization's communication structure.

The law is based on the reasoning that in order for a software module to function, multiple authors must communicate frequently with each other. Therefore, the software interface structure of a system will reflect the social boundaries of the organization(s) that produced it, across which communication is more difficult. Conway's law was intended as a valid sociological observation, although sometimes it's used in a humorous context. It was dubbed Conway's law by participants at the 1968 National Symposium on Modular Programming.

In colloquial terms, it means software or automated systems end up "shaped like" the organizational structure they are designed in or designed for. Some interpretations of the law say this organizational pattern mirroring is a helpful feature of such systems, while other interpretations say it's merely a result of human nature or organizational bias.

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๐Ÿ”— Thousandth of an Inch

๐Ÿ”— Metalworking ๐Ÿ”— Measurement

A thousandth of an inch is a derived unit of length in a system of units using inches. Equal to 1โ„1000 of an inch, a thousandth is commonly called a thou (used for both singular and plural) or particularly in North America a mil (plural mils).

The words are shortened forms of the English and Latin words for "thousand" (mille in Latin). In international engineering contexts, confusion can arise because mil is a formal unit name in North America but mil or mill is also a common colloquial clipped form of millimetre. The units are considerably different: a millimetre is approximately 39 mils.

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๐Ÿ”— Project Coldfeet

๐Ÿ”— United States/U.S. Government ๐Ÿ”— United States

Project COLDFEET was a 1962 Central Intelligence Agency (CIA) operation to extract intelligence from an abandoned Soviet Arctic drifting ice station. Due to the nature of its abandonment as the result of unstable ice, the retrieval of the operatives used the Fulton surface-to-air recovery system.

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๐Ÿ”— Antifuse, the opposite of a fuse

๐Ÿ”— Electronics

An antifuse is an electrical device that performs the opposite function to a fuse. Whereas a fuse starts with a low resistance and is designed to permanently break an electrically conductive path (typically when the current through the path exceeds a specified limit), an antifuse starts with a high resistance, and programming it converts it into a permanent electrically conductive path (typically when the voltage across the antifuse exceeds a certain level). This technology has many applications.

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๐Ÿ”— Thyratron

๐Ÿ”— Electronics ๐Ÿ”— Electrical engineering

A thyratron is a type of gas-filled tube used as a high-power electrical switch and controlled rectifier. Thyratrons can handle much greater currents than similar hard-vacuum tubes. Electron multiplication occurs when the gas becomes ionized, producing a phenomenon known as a Townsend discharge. Gases used include mercury vapor, xenon, neon, and (in special high-voltage applications or applications requiring very short switching times) hydrogen. Unlike a vacuum tube (valve), a thyratron cannot be used to amplify signals linearly.

In the 1920s, thyratrons were derived from early vacuum tubes such as the UV-200, which contained a small amount of argon gas to increase its sensitivity as a radio signal detector, and the German LRS relay tube, which also contained argon gas. Gas rectifiers, which predated vacuum tubes, such as the argon-filled General Electric "Tungar bulb" and the Cooper-Hewitt mercury-pool rectifier, also provided an influence. Irving Langmuir and G. S. Meikle of GE are usually cited as the first investigators to study controlled rectification in gas tubes, about 1914. The first commercial thyratrons appeared circa 1928.

The term "thyratron" is derived from Ancient Greek "ฮธฯฯฮฑ" ("thyra"), meaning "door" or "valve". The term "thyristor" was further derived from a combination of "thyratron" and "transistor". Since the 1960s thyristors have replaced thyratrons in most low- and medium-power applications.

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๐Ÿ”— 1989 Tiananmen Square Protests

๐Ÿ”— Human rights ๐Ÿ”— History ๐Ÿ”— Military history ๐Ÿ”— Crime ๐Ÿ”— China ๐Ÿ”— Politics ๐Ÿ”— Socialism ๐Ÿ”— Law Enforcement ๐Ÿ”— Sociology ๐Ÿ”— Sociology/social movements ๐Ÿ”— Military history/Cold War ๐Ÿ”— Military history/Asian military history ๐Ÿ”— Military history/Chinese military history

The Tiananmen Square protests or Tiananmen Square Incident, commonly known in mainland China as the June Fourth Incident (Chinese: ๅ…ญๅ››ไบ‹ไปถ; pinyin: liรนsรฌ shรฌjiร n, literally six-four incident), were student-led demonstrations held in Tiananmen Square in Beijing during 1989. The popular national movement inspired by the Beijing protests is sometimes called the '89 Democracy Movement (Chinese: ๅ…ซไนๆฐ‘้‹; pinyin: bฤjiว” mรญnyรนn). The protests started on April 15 and were forcibly suppressed on June 4 when the government declared martial law and sent the military to occupy central parts of Beijing. In what became known as the Tiananmen Square Massacre (Chinese: ๅคฉๅฎ‰้–€ๅคงๅฑ ๆฎบ; pinyin: tiฤn'ฤnmรฉn dร  tรบshฤ), troops with assault rifles and tanks fired at the demonstrators and those trying to block the military's advance into Tiananmen Square. Estimates of the death toll vary from several hundred to several thousand, with thousands more wounded.

Set off by the death of pro-reform Communist general secretary Hu Yaobang in April 1989, amid the backdrop of rapid economic development and social changes in post-Mao China, the protests reflected anxieties about the country's future in the popular consciousness and among the political elite. The reforms of the 1980s had led to a nascent market economy which benefited some people but seriously disaffected others, and the one-party political system also faced a challenge of legitimacy. Common grievances at the time included inflation, corruption, limited preparedness of graduates for the new economy, and restrictions on political participation. The students called for greater accountability, constitutional due process, democracy, freedom of the press, and freedom of speech, although they were highly disorganized and their goals varied. At the height of the protests, about 1ย million people assembled in the Square.

As the protests developed, the authorities responded with both conciliatory and hardline tactics, exposing deep divisions within the party leadership. By May, a student-led hunger strike galvanized support for the demonstrators around the country, and the protests spread to some 400 cities. Ultimately, China's paramount leader Deng Xiaoping and other Communist Party elders believed the protests to be a political threat and resolved to use force. The State Council declared martial law on May 20 and mobilized as many as 300,000 troops to Beijing. The troops advanced into central parts of Beijing on the city's major thoroughfares in the early morning hours of June 4, killing both demonstrators and bystanders in the process.

The international community, human rights organizations, and political analysts condemned the Chinese government for the massacre. Western countries imposed arms embargoes on China. The Chinese government made widespread arrests of protesters and their supporters, suppressed other protests around China, expelled foreign journalists, strictly controlled coverage of the events in the domestic press, strengthened the police and internal security forces, and demoted or purged officials it deemed sympathetic to the protests. More broadly, the suppression halted the policies of liberalization in the 1980s. Considered a watershed event, the protests set the limits on political expression in China up to the present day. Its memory is widely associated with questioning the legitimacy of Communist Party rule and remains one of the most sensitive and most widely censored topics in China.

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๐Ÿ”— Pixel Art Scaling Algorithms

๐Ÿ”— Computer graphics

Pixel-art scaling algorithms are graphical filters that are often used in video game console emulators to enhance hand-drawn 2D pixel art graphics. The re-scaling of pixel art is a specialist sub-field of image rescaling.

As pixel-art graphics are usually in very low resolutions, they rely on careful placing of individual pixels, often with a limited palette of colors. This results in graphics that rely on a high amount of stylized visual cues to define complex shapes with very little resolution, down to individual pixels. This makes image scaling of pixel art a particularly difficult problem.

A number of specialized algorithms have been developed to handle pixel-art graphics, as the traditional scaling algorithms do not take such perceptual cues into account.

Since a typical application of this technology is improving the appearance of fourth-generation and earlier video games on arcade and console emulators, many are designed to run in real time for sufficiently small input images at 60 frames per second. This places constraints on the type of programming techniques that can be used for this sort of real-time processing. Many work only on specific scale factors: 2ร— is the most common, with 3ร—, 4ร—, 5ร— and 6ร— also present.

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