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πŸ”— Triple Fault

πŸ”— Computing πŸ”— Computing/Computer hardware πŸ”— Computing/Software

On the x86 computer architecture, a triple fault is a special kind of exception generated by the CPU when an exception occurs while the CPU is trying to invoke the double fault exception handler, which itself handles exceptions occurring while trying to invoke a regular exception handler.

x86 processors beginning with the 80286 will cause a shutdown cycle to occur when a triple fault is encountered. This typically causes the motherboard hardware to initiate a CPU reset, which, in turn, causes the whole computer to reboot.

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πŸ”— Valid Email Addresses

πŸ”— Technology πŸ”— Internet πŸ”— Computing πŸ”— Computing/Networking

An email address identifies an email box to which email messages are delivered. A wide variety of formats were used in early email systems, but only a single format is used today, following the specifications developed for Internet mail systems since the 1980s. This article uses the term email address to refer to the addr-spec defined in RFC 5322, not to the address that is commonly used; the difference is that an address may contain a display name, a comment, or both.

An email address such as John.Smith@example.com is made up of a local-part, an @ symbol, then a case-insensitive domain. Although the standard requires the local part to be case-sensitive, it also urges that receiving hosts deliver messages in a case-independent fashion, e.g., that the mail system at example.com treat John.Smith as equivalent to john.smith; some mail systems even treat them as equivalent to johnsmith. Mail systems often limit their users' choice of name to a subset of the technically valid characters, and in some cases also limit which addresses it is possible to send mail to.

With the introduction of internationalized domain names, efforts are progressing to permit non-ASCII characters in email addresses.

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πŸ”— Lotka–Volterra Equations

πŸ”— Ecology

The Lotka–Volterra equations, also known as the Lotka–Volterra predator–prey model, are a pair of first-order nonlinear differential equations, frequently used to describe the dynamics of biological systems in which two species interact, one as a predator and the other as prey. The populations change through time according to the pair of equations: d x d t = Ξ± x βˆ’ Ξ² x y , d y d t = βˆ’ Ξ³ y + Ξ΄ x y , {\displaystyle {\begin{aligned}{\frac {dx}{dt}}&=\alpha x-\beta xy,\\{\frac {dy}{dt}}&=-\gamma y+\delta xy,\end{aligned}}}

where

  • the variable x is the population density of prey (for example, the number of rabbits per square kilometre);
  • the variable y is the population density of some predator (for example, the number of foxes per square kilometre);
  • d y d t {\displaystyle {\tfrac {dy}{dt}}} and d x d t {\displaystyle {\tfrac {dx}{dt}}} represent the instantaneous growth rates of the two populations;
  • t represents time;
  • The prey's parameters, Ξ± and Ξ², describe, respectively, the maximum prey per capita growth rate, and the effect of the presence of predators on the prey death rate.
  • The predator's parameters, Ξ³, Ξ΄, respectively describe the predator's per capita death rate, and the effect of the presence of prey on the predator's growth rate.
  • All parameters are positive and real.

The solution of the differential equations is deterministic and continuous. This, in turn, implies that the generations of both the predator and prey are continually overlapping.

The Lotka–Volterra system of equations is an example of a Kolmogorov population model (not to be confused with the better known Kolmogorov equations), which is a more general framework that can model the dynamics of ecological systems with predator–prey interactions, competition, disease, and mutualism.

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πŸ”— Perl 6 new regexp rules

πŸ”— Computing πŸ”— Perl

Raku rules are the regular expression, string matching and general-purpose parsing facility of Raku, and are a core part of the language. Since Perl's pattern-matching constructs have exceeded the capabilities of formal regular expressions for some time, Raku documentation refers to them exclusively as regexes, distancing the term from the formal definition.

Raku provides a superset of Perl 5 features with respect to regexes, folding them into a larger framework called rules, which provide the capabilities of a parsing expression grammar, as well as acting as a closure with respect to their lexical scope. Rules are introduced with the rule keyword, which has a usage quite similar to subroutine definitions. Anonymous rules can be introduced with the regex (or rx) keyword, or simply be used inline as regexes were in Perl 5 via the m (matching) or s (substitution) operators.

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πŸ”— Reversible computing

πŸ”— Technology πŸ”— Computing πŸ”— Computer science

Reversible computing is a model of computing where the computational process to some extent is time-reversible. In a model of computation that uses deterministic transitions from one state of the abstract machine to another, a necessary condition for reversibility is that the relation of the mapping from (nonzero-probability) states to their successors must be one-to-one. Reversible computing is a form of unconventional computing.

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πŸ”— Wikipedia lets you create books

This Help page is about Wikipedia books created on Wikipedia.

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πŸ”— Windy City Heat

πŸ”— Film πŸ”— Film/American cinema πŸ”— Comedy πŸ”— Chicago

Windy City Heat is a made-for-TV reality film produced by Comedy Central. It first aired on October 12, 2003.

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πŸ”— Door to Hell

πŸ”— Christianity πŸ”— Mythology

The gates of hell are various places on the surface of the world that have acquired a legendary reputation for being entrances to the underworld. Often they are found in regions of unusual geological activity, particularly volcanic areas, or sometimes at lakes, caves, or mountains.

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πŸ”— John McCarthy Has Died

πŸ”— Biography πŸ”— California πŸ”— Computing πŸ”— Chess πŸ”— Biography/science and academia πŸ”— Computing/Computer science πŸ”— Robotics πŸ”— Stanford University

John McCarthy (September 4, 1927 – October 24, 2011) was an American computer scientist and cognitive scientist. McCarthy was one of the founders of the discipline of artificial intelligence. He coined the term "artificial intelligence" (AI), developed the Lisp programming language family, significantly influenced the design of the ALGOL programming language, popularized time-sharing, invented garbage collection, and was very influential in the early development of AI.

McCarthy spent most of his career at Stanford University. He received many accolades and honors, such as the 1971 Turing Award for his contributions to the topic of AI, the United States National Medal of Science, and the Kyoto Prize.

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πŸ”— 2022 Oder Environmental Disaster

πŸ”— International relations πŸ”— Germany πŸ”— Disaster management πŸ”— Poland πŸ”— Current events πŸ”— Rivers

The 2022 Oder environmental disaster is a mass die-off of fish, beavers and other wildlife in the Oder river in Poland and Germany, causing a health and environmental crisis in large parts of the country and subsequently a political scandal.

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