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π Core War
Core War is a 1984 programming game created by D. G. Jones and A. K. Dewdney in which two or more battle programs (called "warriors") compete for control of a virtual computer. These battle programs are written in an abstract assembly language called Redcode.
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- "Core War, a very old game about programming" | 2023-08-14 | 66 Upvotes 14 Comments
- "Core War" | 2022-02-11 | 236 Upvotes 50 Comments
π ACTA will force border searches of laptops, smartphones for pirated content
The Anti-Counterfeiting Trade Agreement (ACTA) was a proposed multilateral treaty for the purpose of establishing international standards for intellectual property rights enforcement. The agreement aims to establish an international legal framework for targeting counterfeit goods, generic medicines and copyright infringement on the Internet, and would create a new governing body outside existing forums, such as the World Trade Organization, the World Intellectual Property Organization, and the United Nations.
The agreement was signed in October 2011 by Australia, Canada, Japan, Morocco, New Zealand, Singapore, South Korea, and the United States. In 2012, Mexico, the European Union and 22 countries that are member states of the European Union signed as well. One signatory (Japan) has ratified (formally approved) the agreement, which would come into force in countries that ratified it after ratification by six countries.
Industrial groups with interests in copyright, trademarks and other types of intellectual property said that ACTA was a response to "the increase in global trade of counterfeit goods and pirated copyright protected works". Organizations such as the Motion Picture Association of America and International Trademark Association are understood to have had a significant influence over the ACTA agenda.
Organisations representing citizens and non-governmental interests argued that ACTA could infringe fundamental rights including freedom of expression and privacy. ACTA has also been criticised by Doctors Without Borders for endangering access to medicines in developing countries. The nature of negotiations was criticized as secretive and has excluded non-governmental organization, developing countries and the general public from the agreement's negotiation process and it has been described as policy laundering by critics including the Electronic Frontier Foundation and the Entertainment Consumers Association.
The signature of the EU and many of its member states resulted in widespread protests across Europe. European Parliament rapporteur Kader Arif resigned. His replacement, British MEP David Martin, recommended that the Parliament should reject ACTA, stating: "The intended benefits of this international agreement are far outweighed by the potential threats to civil liberties". On 4 July 2012, the European Parliament declined its consent, effectively rejecting it, 478 votes to 39, with 165 abstentions.
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- "ACTA will force border searches of laptops, smartphones for pirated content" | 2012-01-22 | 412 Upvotes 191 Comments
π Timeline of programming languages
This is a record of historically important programming languages, by decade.
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- "Timeline of programming languages" | 2017-12-17 | 56 Upvotes 23 Comments
π Emperor Norton
Joshua Abraham Norton (February 4, 1818Β β January 8, 1880), known as Emperor Norton, was a citizen of San Francisco, California, who proclaimed himself "Norton I, Emperor of the United States" in 1859. In 1863 he took the secondary title of "Protector of Mexico" after Napoleon III invaded that country. Norton was born in England but spent most of his early life in South Africa. He sailed west after the death of his mother in 1846 and his father in 1848, arriving in San Francisco possibly in November 1849.
Norton initially made a living as a businessman, but he lost his fortune investing in Peruvian rice to sell in China due to a Chinese rice shortage. He bought rice at 12 cents per pound from Peruvian ships, but more Peruvian ships arrived in port which caused the price to drop sharply to 4 cents. He then lost a lawsuit in which he tried to void his rice contract, and his public prominence faded. He re-emerged in September 1859, laying claim to the position of Emperor of the United States. Though Norton received many favors from the city, merchants also capitalized on his notoriety by selling souvenirs bearing his name. "San Francisco lived off the Emperor Norton," Norton's biographer William Drury wrote, "not Norton off San Francisco."
Norton had no formal political power; nevertheless, he was treated deferentially in San Francisco, and currency issued in his name was honored in the establishments that he frequented. Some considered him insane or eccentric, but citizens of San Francisco celebrated his imperial presence and his proclamations, such as his order that the United States Congress be dissolved by force and his numerous decrees calling for the construction of a bridge and tunnel crossing San Francisco Bay to connect San Francisco with Oakland.
On January 8, 1880, Norton collapsed at the corner of California and Dupont (now Grant) streets and died before he could be given medical treatment. Upwards of 30,000 people lined the streets of San Francisco to pay him homage at his funeral. Norton has been immortalized as the basis of characters in the literature of Mark Twain, Robert Louis Stevenson, Christopher Moore, Morris and RenΓ© Goscinny, Selma LagerlΓΆf, and Neil Gaiman.
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- "Emperor Norton" | 2019-08-09 | 92 Upvotes 26 Comments
- "Norton I, Emperor of the United States" | 2018-01-30 | 32 Upvotes 1 Comments
- "Emperor Norton" | 2015-06-08 | 89 Upvotes 14 Comments
π Sortition
In governance, sortition (also known as selection by lot, allotment, demarchy, or Stochocracy) is the selection of political officials as a random sample from a larger pool of candidates. Filling individual posts or, more usually in its modern applications, to fill collegiate chambers. The system intends to ensure that all competent and interested parties have an equal chance of holding public office. It also minimizes factionalism, since there would be no point making promises to win over key constituencies if one was to be chosen by lot, while elections, by contrast, foster it. In ancient Athenian democracy, sortition was the traditional and primary method for appointing political officials, and its use was regarded as a principal characteristic of democracy.
Today, sortition is commonly used to select prospective jurors in common law-based legal systems and is sometimes used in forming citizen groups with political advisory power (citizens' juries or citizens' assemblies).
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- "Sortition" | 2022-10-14 | 12 Upvotes 1 Comments
- "Sortition" | 2020-06-01 | 189 Upvotes 116 Comments
- "Sortition" | 2015-11-11 | 108 Upvotes 62 Comments
π Floyd-Steinberg Dithering Algorithm
FloydβSteinberg dithering is an image dithering algorithm first published in 1976 by Robert W. Floyd and Louis Steinberg. It is commonly used by image manipulation software, for example when an image is converted into GIF format that is restricted to a maximum of 256 colors.
The algorithm achieves dithering using error diffusion, meaning it pushes (adds) the residual quantization error of a pixel onto its neighboring pixels, to be dealt with later. It spreads the debt out according to the distribution (shown as a map of the neighboring pixels):
The pixel indicated with a star (*) indicates the pixel currently being scanned, and the blank pixels are the previously-scanned pixels. The algorithm scans the image from left to right, top to bottom, quantizing pixel values one by one. Each time the quantization error is transferred to the neighboring pixels, while not affecting the pixels that already have been quantized. Hence, if a number of pixels have been rounded downwards, it becomes more likely that the next pixel is rounded upwards, such that on average, the quantization error is close to zero.
The diffusion coefficients have the property that if the original pixel values are exactly halfway in between the nearest available colors, the dithered result is a checkerboard pattern. For example, 50% grey data could be dithered as a black-and-white checkerboard pattern. For optimal dithering, the counting of quantization errors should be in sufficient accuracy to prevent rounding errors from affecting the result.
In some implementations, the horizontal direction of scan alternates between lines; this is called "serpentine scanning" or boustrophedon transform dithering.
In the following pseudocode we can see the algorithm described above. This works for any approximately linear encoding of pixel values, such as 8-bit integers, 16-bit integers or real numbers in the range [0,1].
for each y from top to bottom do
for each x from left to right do
oldpixelΒ := pixel[x][y]
newpixelΒ := find_closest_palette_color(oldpixel)
pixel[x][y]Β := newpixel
quant_errorΒ := oldpixel - newpixel
pixel[x + 1][y ]Β := pixel[x + 1][y ] + quant_error Γ 7 / 16
pixel[x - 1][y + 1]Β := pixel[x - 1][y + 1] + quant_error Γ 3 / 16
pixel[x ][y + 1]Β := pixel[x ][y + 1] + quant_error Γ 5 / 16
pixel[x + 1][y + 1]Β := pixel[x + 1][y + 1] + quant_error Γ 1 / 16
When converting 16 bit greyscale to 8 bit, find_closest_palette_color() may perform just a simple rounding, for example:
find_closest_palette_color(oldpixel) = round(oldpixel / 256)
The pseudocode can result in pixel values exceeding the valid values (such as greater than 1 in a [0,1] representation). Such values should ideally be clipped by the find_closest_palette_color() function, rather than clipping the intermediate values, since a subsequent error may bring the value back into range. However, if fixed-width integers are used, wrapping of intermediate values would cause inversion of black and white, and so should be avoided.
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- "Floyd-Steinberg Dithering Algorithm" | 2020-12-30 | 11 Upvotes 7 Comments
π M4 (computer language)
m4 is a general-purpose macro processor included in all UNIX-like operating systems, and is a component of the POSIX standard.
The language was designed by Brian Kernighan and Dennis Ritchie for the original versions of UNIX. It is an extension of an earlier macro processor m3, written by Ritchie for an unknown AP-3 minicomputer.
The macro preprocessor operates as a text-replacement tool. It is employed to re-use text templates, typically in computer programming applications, but also in text editing and text-processing applications. Most users require m4 as a dependency of GNU autoconf.
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- "M4 (computer language)" | 2018-08-17 | 70 Upvotes 26 Comments
π Commons-based peer production
Commons-based peer production (CBPP) is a term coined by Harvard Law School professor Yochai Benkler. It describes a model of socio-economic production in which large numbers of people work cooperatively; usually over the Internet. Commons-based projects generally have less rigid hierarchical structures than those under more traditional business models. Oftenβbut not alwaysβcommons-based projects are designed without a need for financial compensation for contributors. For example, sharing of STL (file format) design files for objects freely on the internet enables anyone with a 3-D printer to digitally replicate the object saving the prosumer significant money.
The term is often used interchangeably with the term social production.
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- "Commons-based peer production" | 2016-01-10 | 13 Upvotes 2 Comments
π Solar storm of 1859
The solar storm of 1859 (also known as the Carrington Event) was a powerful geomagnetic storm during solar cycle 10 (1855β1867). A solar coronal mass ejection (CME) hit Earth's magnetosphere and induced the largest geomagnetic storm on record, September 1β2, 1859. The associated "white light flare" in the solar photosphere was observed and recorded by British astronomers Richard C. Carrington (1826β1875) and Richard Hodgson (1804β1872). The storm caused strong auroral displays and wrought havoc with telegraph systems. The now-standard unique IAU identifier for this flare is SOL1859-09-01.
A solar storm of this magnitude occurring today would cause widespread electrical disruptions, blackouts and damage due to extended outages of the electrical grid. The solar storm of 2012 was of similar magnitude, but it passed Earth's orbit without striking the planet, missing by nine days.
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- "Solar Storm of 1859" | 2020-05-04 | 148 Upvotes 84 Comments
- "Solar storm of 1859" | 2018-11-04 | 109 Upvotes 45 Comments
π Eagle Cash
Eagle Cash (stylized as EagleCash), and sister program EZpay, are cash management applications that use stored-value card technology to process financial transactions in "closed-loop" operating environments. The United States Department of the Treasury sponsors the programs for the U.S. Armed Forces. The Federal Reserve Bank of Boston administers the programs for the Treasury, and they are in use at approved U.S. military facilities inside and outside the continental United States. The systems use a plastic payment card, similar to a credit or debit card, which has an embedded microchip that tracks the card's balance and interfaces with encrypted card readers. This method allows soldiers to purchase goods and services at U.S. military posts and canteens, without carrying cash, or manage their personal bank accounts while on deployment or in training. The program reduces the amount of American currency required overseas, reduces theft, saves thousands of man-hours in labor, helps reduce the risk of transporting cash in combat environments, and increases security and convenience for service members. It helped reduce or eliminate the need for cash and money orders.
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- "Eagle Cash" | 2021-01-01 | 137 Upvotes 103 Comments