All articles A–Z
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Simple group
A simple group is a nontrivial group whose only normal subgroups are the identity and itself, playing the role in group theory that primes play in arithmetic.
Simple harmonic motion
Simple harmonic motion is oscillatory motion in which the restoring force is proportional to displacement from equilibrium, as with a mass on a spring obeying Hooke's law.
Simple interest
Simple interest is interest computed only on the principal, with I = P·r·t and total A = P(1 + rt), so growth is linear, unlike compound interest where interest earns interest.
Simple interrupted stitch
The simple interrupted stitch is a basic surgical suturing technique in which each stitch is a single loop tied off individually, so one failed stitch leaves the others intact.
Simple Kapadia
Simple Kapadia (1958–2009) was a Hindi film actress and costume designer, younger sister of Dimple Kapadia, who won the National Film Award for Rudaali (1992).
Simple Knowledge Organization System
Simple Knowledge Organization System, or SKOS, is a W3C standard data model, expressed as an RDF vocabulary, for publishing thesauri, taxonomies, and classification schemes on the Web.
Simple linear regression
Simple linear regression, or simple regression, is a statistical method that models one response variable as a straight-line function of one explanatory variable, fitted by least squares.
Simple living
Simple living (voluntary simplicity): a voluntarily chosen, less consumption-focused lifestyle coined as a term by Richard Gregg in 1936 and popularized by Duane Elgin; linked to modestly higher well-being (g = .28) and a 23% smaller ecological footprint.
Simple machine
A simple machine is a device with few or no moving parts that changes the force needed to do work, such as a lever, pulley, or ramp.
Simple Mail Transfer Protocol
Simple Mail Transfer Protocol (SMTP) is the Internet standard protocol for transferring email between servers over TCP, first defined in RFC 821 in August 1982.
Simple Minds
Simple Minds: Scottish rock band formed in Glasgow in 1977 from Johnny & the Self-Abusers, led by Jim Kerr and Charlie Burchill. Known for New Gold Dream (1982), Sparkle in the Rain (1984), and the US number-one "Don't You (Forget About Me)"; new album Sacrosanct due 2027.
Simple module
A simple module, also called an irreducible module, is a nonzero module over a ring whose only submodules are zero and itself, corresponding to irreducible representations.
Simple Network Management Protocol
The Simple Network Management Protocol (SNMP) is an Internet-standard application-layer protocol for monitoring and managing network devices such as routers and switches, in use since 1990 and now recommended only in its secure SNMPv3 form.
Simple past
The simple past (past simple, preterite, past indefinite) is the English tense for completed actions, habits, and states at a definite past time, formed with -ed or irregular forms and did in questions and negatives.
Simple Plan
Simple Plan, Canadian pop-punk band formed 1999 in Montreal by Pierre Bouvier, Chuck Comeau, Jeff Stinco, Sebastien Lefebvre, and David Desrosiers; debut No Pads, No Helmets…Just Balls (2002), breakthrough Still Not Getting Any... (2004) with Welcome to My Life.
Simple preference optimization
Simple preference optimization (SimPO) is a reference-free preference optimization algorithm for aligning large language models, introduced by Princeton NLP in May 2024 as a simpler alternative to DPO.
Simple present
Simple present (present simple): English verb form using the base verb with third-person-singular -s, for habits, general truths, permanent states, timetable futures, and instructions; negatives and questions use do/does.
Simple random sample
A simple random sample is a sample drawn so that every subset of units has the same chance of selection, the baseline probability sampling design in statistics.
Simple renal cyst
Simple renal cyst (simple kidney cyst): benign, thin-walled, fluid-filled sac in the kidney, found in about 1 in 10 people and nearly 1 in 5 over age 50, more common in men; usually symptomless, treated only if symptomatic with sclerotherapy or laparoscopic surgery.
Simple Sabotage Field Manual
Simple Sabotage Field Manual: 1944 OSS guide (authorized by Donovan, declassified by CIA in 2008) teaching citizen-saboteurs in occupied Europe to disrupt the enemy via petty physical damage and organizational obstruction tactics.
Simple Service Discovery Protocol
The Simple Service Discovery Protocol (SSDP) is a UDP-based protocol for advertising and discovering services on local networks, best known as the discovery layer of UPnP.
Simple set (computability theory)
A simple set, introduced by Emil Post in 1944, is a recursively enumerable set of natural numbers whose complement is infinite but contains no infinite recursively enumerable subset.
Simple suspension bridge
A simple suspension bridge is a bridge whose walkway lies on or between two sagging cables anchored at each end, without vertical suspenders, so it is restricted to pedestrians and suits difficult terrain.
Simple theory (model theory)
In model theory, a simple theory is a complete first-order theory in which no formula has the tree property. Introduced by Shelah, the class properly contains the stable theories.
Simple Verses
Simple Verses (Versos sencillos) is an 1891 collection of 46 poems by the Cuban poet and patriot José Martí, published in New York during his exile from Cuba.
SimpleBet
SimpleBet was a New York-based B2B sports-betting technology company founded in 2018 that used machine learning to turn live sports moments into bettable micro-markets; DraftKings acquired it in 2024.
SimpleFOC
SimpleFOC, also known as Arduino-FOC or Arduino Simple Field Oriented Control, is an open-source MIT-licensed Arduino library implementing field oriented control of brushless DC and stepper motors on hobby-grade microcontrollers.
SimpleQA
SimpleQA is an OpenAI factuality benchmark released in November 2024, containing 4,326 short fact-seeking questions with single verifiable answers, built adversarially against GPT-4 to measure hallucination rates.
Simplex
A simplex, plural simplexes or simplices, is the simplest convex polytope of a given dimension, the convex hull of k + 1 points: point, segment, triangle, tetrahedron, and beyond.
Simplex algorithm
The simplex algorithm, also called the simplex method, is a pivoting method for solving linear programs by moving between vertices of the feasible polyhedron. George Dantzig formulated it in 1947.