Random Articles (Page 6)

Have a deep view into what people are curious about.

πŸ”— The Illiac IV Computer

πŸ”— Computing πŸ”— Computing/Computer hardware

The ILLIAC IV was the first massively parallel computer. The system was originally designed to have 256 64-bit floating point units (FPUs) and four central processing units (CPUs) able to process 1 billion operations per second. Due to budget constraints, only a single "quadrant" with 64 FPUs and a single CPU was built. Since the FPUs all had to process the same instruction – ADD, SUB etc. – in modern terminology the design would be considered to be single instruction, multiple data, or SIMD.

The concept of building a computer using an array of processors came to Daniel Slotnick while working as a programmer on the IAS machine in 1952. A formal design did not start until 1960, when Slotnick was working at Westinghouse Electric and arranged development funding under a US Air Force contract. When that funding ended in 1964, Slotnick moved to the University of Illinois and joined the Illinois Automatic Computer (ILLIAC) team. With funding from Advanced Research Projects Agency (ARPA), they began the design of a newer concept with 256 64-bit processors instead of the original concept with 1,024 1-bit processors.

While the machine was being built at Burroughs, the university began building a new facility to house it. Political tension over the funding from the US Department of Defense led to the ARPA and the University fearing for the machine's safety. When the first 64-processor quadrant of the machine was completed in 1972, it was sent to the NASA Ames Research Center in California. After three years of thorough modification to fix various flaws, ILLIAC IV was connected to the ARPANet for distributed use in November 1975, becoming the first network-available supercomputer, beating the Cray-1 by nearly 12 months.

Running at half its design speed, the one-quadrant ILLIAC IV delivered 50Β MFLOP peak, making it the fastest computer in the world at that time. It is also credited with being the first large computer to use solid-state memory, as well as the most complex computer built to date, with over 1 million gates. Generally considered a failure due to massive budget overruns, the design was instrumental in the development of new techniques and systems for programming parallel systems. In the 1980s, several machines based on ILLIAC IV concepts were successfully delivered.

Discussed on

πŸ”— COVFEFE Act

πŸ”— United States/U.S. Government πŸ”— Internet culture πŸ”— Telecommunications πŸ”— Law πŸ”— Politics πŸ”— Popular Culture πŸ”— Donald Trump

The Communications Over Various Feeds Electronically for Engagement Act (COVFEFE Act) is a bill introduced into the United States House of Representatives in 2017 (on June 12), during the 115th United States Congress.

The bill would amend the Presidential Records Act to preserve Twitter posts and other social media interactions of the President of the United States, and to require the National Archives to store such items.

U.S. Representative Mike Quigley, Democrat of Illinois, introduced the legislation in the wake of Donald Trump's routine use of Twitter, stating "In order to maintain public trust in government, elected officials must answer for what they do and say; this includes 140-character tweets. If the president is going to take to social media to make sudden public policy proclamations, we must ensure that these statements are documented and preserved for future reference." If enacted, the bill "would bar the prolifically tweeting president from deleting his posts, as he has sometimes done."

If the bill were enacted, it would see US law treat US presidents' personal social media accounts (such as Trump's "@realDonaldTrump" Twitter account) the same as "official" social media accounts (such as the "@POTUS" Twitter account).

Discussed on

πŸ”— Geneva drive

πŸ”— Technology πŸ”— Physics

The Geneva drive or Maltese cross is a gear mechanism that translates a continuous rotation movement into intermittent rotary motion.

The rotating drive wheel is usually equipped with a pin that reaches into a slot located in the other wheel (driven wheel) that advances it by one step at a time. The drive wheel also has an elevated circular blocking disc that "locks" the rotating driven wheel in position between steps.

Discussed on

πŸ”— Mt.Gox does not mean "Mount" Gox

πŸ”— Companies πŸ”— Internet πŸ”— Crime πŸ”— Finance & Investment πŸ”— Numismatics πŸ”— Websites πŸ”— Websites/Computing πŸ”— Numismatics/Cryptocurrency πŸ”— Cryptocurrency

Mt. Gox was a bitcoin exchange based in Shibuya, Tokyo, Japan. Launched in July 2010, by 2013 and into 2014 it was handling over 70% of all bitcoin (BTC) transactions worldwide, as the largest bitcoin intermediary and the world's leading bitcoin exchange.

In February 2014, Mt. Gox suspended trading, closed its website and exchange service, and filed for bankruptcy protection from creditors. In April 2014, the company began liquidation proceedings.

Mt. Gox announced that approximately 850,000 bitcoins belonging to customers and the company were missing and likely stolen, an amount valued at more than $450 million at the time. Although 200,000 bitcoins have since been "found", the reasons for the disappearanceβ€”theft, fraud, mismanagement, or a combination of theseβ€”were initially unclear. New evidence presented in April 2015 by Tokyo security company WizSec led them to conclude that "most or all of the missing bitcoins were stolen straight out of the Mt. Gox hot wallet over time, beginning in late 2011."

Discussed on

πŸ”— Bang Bang Control

πŸ”— Systems πŸ”— Systems/Control theory

In control theory, a bang–bang controller (2 step or on–off controller), also known as a hysteresis controller, is a feedback controller that switches abruptly between two states. These controllers may be realized in terms of any element that provides hysteresis. They are often used to control a plant that accepts a binary input, for example a furnace that is either completely on or completely off. Most common residential thermostats are bang–bang controllers. The Heaviside step function in its discrete form is an example of a bang–bang control signal. Due to the discontinuous control signal, systems that include bang–bang controllers are variable structure systems, and bang–bang controllers are thus variable structure controllers.

Discussed on

πŸ”— Preparedness Paradox

πŸ”— Disaster management

The preparedness paradox is the proposition that if a society or individual acts effectively to mitigate a potential disaster such as a pandemic, natural disaster or other catastrophe so that it causes less harm, the avoided danger will be perceived as having been much less serious because of the limited damage actually caused. The paradox is the incorrect perception that there had been no need for careful preparation as there was little harm, although in reality the limitation of the harm was due to preparation. Several cognitive biases can consequently hamper proper preparation for future risks.

Discussed on

πŸ”— Flocken Elektrowagen

πŸ”— Environment πŸ”— Automobiles πŸ”— Environment/Green vehicle

The Flocken Elektrowagen is a four-wheeled electric car designed by Andreas Flocken (1845–1913), manufactured in 1888 by Maschinenfabrik A. Flocken in Coburg. It is regarded as the first real electric car.

Discussed on

πŸ”— 100 prisoners problem

πŸ”— Mathematics

The 100 prisoners problem is a mathematical problem in probability theory and combinatorics. In this problem, 100 numbered prisoners must find their own numbers in one of 100 drawers in order to survive. The rules state that each prisoner may open only 50 drawers and cannot communicate with other prisoners. At first glance, the situation appears hopeless, but a clever strategy offers the prisoners a realistic chance of survival. Danish computer scientist Peter Bro Miltersen first proposed the problem in 2003.

Discussed on

πŸ”— Great Woman of Mathematics: Marie-Sophie Germain, 1776-1831

πŸ”— Biography πŸ”— Mathematics πŸ”— France πŸ”— Women scientists πŸ”— Biography/science and academia πŸ”— Women's History πŸ”— Mathematics/Mathematicians

Marie-Sophie Germain (French:Β [maʁi sΙ”fi ʒɛʁmΙ›Μƒ]; 1 April 1776 – 27 June 1831) was a French mathematician, physicist, and philosopher. Despite initial opposition from her parents and difficulties presented by society, she gained education from books in her father's library, including ones by Leonhard Euler, and from correspondence with famous mathematicians such as Lagrange, Legendre, and Gauss (under the pseudonym of Β«Monsieur LeBlancΒ»). One of the pioneers of elasticity theory, she won the grand prize from the Paris Academy of Sciences for her essay on the subject. Her work on Fermat's Last Theorem provided a foundation for mathematicians exploring the subject for hundreds of years after. Because of prejudice against her sex, she was unable to make a career out of mathematics, but she worked independently throughout her life. Before her death, Gauss had recommended that she be awarded an honorary degree, but that never occurred. On 27 June 1831, she died from breast cancer. At the centenary of her life, a street and a girls’ school were named after her. The Academy of Sciences established the Sophie Germain Prize in her honor.

πŸ”— Bunkers in Albania

πŸ”— Military history πŸ”— Military history/Fortifications πŸ”— Military history/Cold War πŸ”— Military history/Balkan military history πŸ”— Albania πŸ”— Military history/European military history

Concrete military bunkers are a ubiquitous sight in Albania, with an average of 5.7 bunkers for every square kilometer (14.7 per square mile). The bunkers (Albanian: bunkerΓ«t) were built during the Hoxhaist government led by the Leader Enver Hoxha from the 1960s to the 1980s, as the government fortified Albania by building more than 750,000 bunkers.

Hoxha's program of "bunkerization" (bunkerizimi) resulted in the construction of bunkers in every corner of the then-People's Socialist Republic of Albania, ranging from mountain passes to city streets. They were never used for their intended purpose during the years that Hoxha governed. The cost of constructing them was a drain on Albania's resources, diverting them away from dealing with the country's housing shortage and poor roads.

The bunkers were abandoned following the dissolution of the communist government in 1992. A few were used in the Insurrection of 1997 and the Kosovo War of 1999. Most are now derelict, though some have been reused for a variety of purposes, including residential accommodation, cafΓ©s, storehouses, and shelters for animals or the homeless.

Discussed on