All articles starting with S
44,216 articles
Surrogacy laws by country
Surrogacy laws by country: national rules on whether surrogacy is banned, altruistic-only, or commercial. No international treaty governs cross-border recognition; ECtHR Mennesson case law, HCCH project, and differing US, Italian, Greek, UK rules.
Surrogate data testing
Surrogate data testing is a Monte Carlo hypothesis test for time series, comparing a statistic against randomized copies that preserve linear properties like the Fourier spectrum.
Surrogate key
Surrogate key: warehouse-generated artificial identifier (usually a sequential integer) replacing a source natural key as a dimension table's primary key; enables multi-source consolidation and SCD type 2 history, with the date dimension a YYYYMMDD exception.
Surrogate model
A surrogate model is a computationally cheap approximation of an expensive simulator, built from a modest number of training evaluations and used for prediction, optimization, and sensitivity analysis.
Surrogate optimization
Surrogate optimization finds optima of expensive black-box functions by building a cheap approximate model, the surrogate, to decide where to evaluate next; Bayesian optimization is the most common form.
Surrogate Safety Assessment Model
The Surrogate Safety Assessment Model (SSAM) is a free software tool from the U.S. Federal Highway Administration that evaluates road safety from traffic simulation data.
Surrogate-based optimization
Surrogate-based optimization (SBO) is an engineering optimization strategy that replaces a costly model, such as a CFD simulation, with a cheap surrogate approximation to find optimized designs with fewer expensive evaluations.
Surrogate-V
Surrogate-V (Суррогат-В, code name Vedomy) is a Russian extra-large autonomous underwater vehicle by Rubin, designed to work with submarines by imitating their signatures as a decoy.
Surrogates
Surrogates is a 2009 American science fiction action film directed by Jonathan Mostow, in which people live through robotic duplicates and Bruce Willis plays an FBI agent.
Surround sound
Surround sound: multichannel audio over speakers around the listener, from 1941 Fantasound and 1970s quadraphonic to Dolby Digital 5.1, DTS, and object-based Dolby Atmos, DTS:X, and Auro-3D.
Surrounded (web series)
Surrounded is Jubilee Media's viral YouTube debate web series, premiered September 2024, in which one guest debates about 20 opposing participants who vote debaters out with red flags.
Surrounded by Idiots
Surrounded by Idiots (Omgiven av idioter), Thomas Erikson's 2014 Swedish bestseller (English 2019), popularizes a four-color DISC/DISA personality model; researchers classify it as pseudoscience.
Surrounded Islands
Surrounded Islands was a temporary 1983 environmental installation by Christo and Jeanne-Claude, surrounding eleven artificial islands in Biscayne Bay, Miami, with floating pink fabric for two weeks.
Surrozen, Inc.
Surrozen, Inc. is a South San Francisco, California biotechnology company, founded in 2017, that develops Wnt pathway antibodies and pivoted to retinal disease programs in 2025.
Surry County, Virginia
Surry County, Virginia: rural county formed in 1652 from James City County, named for Surrey, England; population 6,561 (2020); linked to Jamestown by the free Jamestown-Scotland Ferry; home of Bacon's Castle and Chippokes State Park.
Surry Power Station
Surry Power Station is a two-unit nuclear power plant on the James River in Surry County, Virginia, operated by Dominion Energy and providing about 15 percent of its Virginia customers' electricity.
Sursagar
Sursagar (सूरसागर, "Sur's Ocean") is the principal collection of Krishna-devotion poetry attributed to the sixteenth-century Braj poet Surdas, retelling Krishna's life from birth to the reunion at Kurukshetra, and the only work universally accepted as his.
Surströmming
Surströmming, Swedish fermented Baltic herring from the 16th century, ripened in 17% brine by Haloanaerobium bacteria, sold from the third Thursday of August, eaten in tunnbröd wraps.
SURTAVI trial
SURTAVI (Surgical Replacement and Transcatheter Aortic Valve Implantation), NCT01586910: Medtronic-funded randomized trial showing self-expanding CoreValve/Evolut R TAVR noninferior to surgery at 2 and 5 years in 1,746 intermediate-risk aortic stenosis patients.
Surtr
Surtr (Surt, Surtur), Old Norse "the black one," is the Norse fire giant ruling Muspell in the south; at Ragnarök he leads the sons of Muspell over Bifröst, kills Freyr, and burns the world, also giving his name to Surtshellir cave and Surtsey.
Surtrac
Surtrac (Scalable Urban Traffic Control) is a decentralized adaptive traffic signal control system developed at Carnegie Mellon University, first deployed in Pittsburgh in 2012, cutting travel times by about 25%.
Surtsey
Surtsey is a volcanic island about 32 km off Iceland's south coast, formed by eruptions from 1963 to 1967 and protected since birth as a pristine natural laboratory for studying biological colonization of new land.
Surtshellir
Surtshellir is a lava tube cave about 1,600 m long in the Hallmundarhraun lava field of western Iceland, containing a Viking Age archaeological site once thought an outlaw shelter.
Surufatinib
Surufatinib (HMPL-012, Sulanda) is HUTCHMED's oral kinase inhibitor of VEGFR1-3, FGFR1, and CSF-1R, approved in China (2020, 2021) for extrapancreatic and pancreatic neuroendocrine tumors based on the SANET-ep and SANET-p phase 3 trials; not FDA or EMA approved.
Surulere
Surulere is a residential and commercial Local Government Area on the Lagos mainland, Nigeria, created in 1991, home to the National Stadium (1972), Teslim Balogun Stadium, Fela Kuti's Kalakuta Republic, and the Ojuelegba transport hub.
Surupa Dorsa
Surupa Dorsa is a ~981 km groove belt (extensional ridge feature) on Venus at 71.7N, 209E in Vinmara Planitia, IAU-named 1997 for a Hindu rain-bringing sky goddess; interpreted as possible localized spreading.
Šuruppak
Šuruppak (modern Tell Fara, Iraq), major Sumerian city on the Euphrates between Nippur and Uruk, occupied c. 3000–2000 BC; Fara-period tablets, flood-hero tradition, excavated 1902–03 and 2022–2024.
Sururu Oil and Gas Field
Sururu is a pre-salt oil field in the Santos Basin, offshore Brazil, part of the Iara cluster, producing through the P-68 floating vessel since November 2019.
Surus
Surus, also given as Syrus, was a Carthaginian war elephant, the only one of Hannibal's elephants named in ancient sources, notable for one broken tusk.
Surveen Chawla
Surveen Chawla is an Indian actress and dancer, born in 1984 in Chandigarh, who rose from television serials to Punjabi films, Hate Story 2, and streaming series.