All articles starting with R

Rapidly-exploring random graph

The rapidly-exploring random graph (RRG) is a sampling-based motion planning algorithm introduced by Sertac Karaman and Emilio Frazzoli at MIT in 2010, whose best path converges to the optimal path as samples grow.

RapidMiner

RapidMiner is a data science and machine learning software platform, begun as the open-source tool YALE, in which users build analyses as visual workflows of operators without writing code.

Rapido (company)

Rapido, legally Roppen Transportation Services, is an Indian ride-hailing platform founded in Bengaluru in 2015 that provides bike taxi, auto rickshaw, and cab services in more than 100 cities.

RAPIDO trial

RAPIDO trial (NCT01558921), a phase 3 study of short-course radiotherapy plus preoperative CAPOX/FOLFOX before surgery versus chemoradiotherapy in high-risk locally advanced rectal cancer; reduced 3-year disease-related treatment failure (23.7% vs 30.4%) and doubled pCR, with no overall survival difference.

RapidSOS

RapidSOS is an American emergency-response technology company that sends location, health, and vehicle data from connected devices to 911 centers and responders. It was founded in 2012.

Rapidum

Rapidum (Sour Djouab) was a Roman camp founded in 122 AD under Hadrian by the Cohors II Sardorum in Mauretania Caesariensis, Algeria, which grew into a walled town of about 8,000 inhabitants, was destroyed around 270-275, rebuilt under the Tetrarchy, and disappeared in the fourth century.

Rapier

A rapier, or espada ropera, is a long, slender one-handed sword with an elaborate guard, worn with civilian dress in Europe from the early 1500s for thrusting in duels.

Rapier (missile)

Rapier, also known as Rapier FSC, is a British short-range surface-to-air missile system developed by BAC to defend troops and airfields, entering service in the 1960s.

Rapini

Rapini, also called broccoli rabe or broccoli raab, is a bitter green vegetable in the mustard family, a turnip relative grown for its leaves, stems, and small unopened buds.

Rapinium

Rapinium, an ancient coastal positio and harbor of Etruria between Centumcellae and Graviscae, named in the Itinerarium Maritimum; proposed near the Mignone mouth and at La Frasca, Civitavecchia.

Sep 19, 2026

Rapiqum

Rapiqum, also written Rapiqu, was an ancient city on the Euphrates between Suhûm and Babylonia, probably at Tell Anbar near Fallujah, Iraq, attested from the early second millennium BC into Assyrian times.

Rapiscan Systems

Rapiscan Systems is an American security screening company, a subsidiary of OSI Systems, that makes X-ray, CT, and metal detection systems for inspecting baggage, cargo, and people.

Rapman

Rapman (Andrew Onwubolu) is a British rapper, writer, and film director from Deptford, south London, creator of the YouTube series Shiro's Story, the 2019 film Blue Story, and Netflix's Supacell (2024).

Rappahannock River

Rappahannock River: Virginia river rising at Chester Gap, flowing about 184 miles to the Chesapeake Bay; 2,715 sq mi watershed, fall line at Fredericksburg, State Scenic upper 62 miles.

Rappaport

"Rappaport" is a proposed monospecific bacterial genus erected in 2017 for a bacterium isolated from a human blood culture in Israel; its name has not been validly published.

Rapper's Delight

Rapper's Delight, also known as the Sugarhill Gang's debut single, is the 1979 Sylvia Robinson-produced rap record on Sugar Hill Records that became hip hop's first commercial hit, built on Chic's "Good Times" and reaching Billboard's Top 40.

Sep 19, 2026

Rappi

Rappi is a Colombian on-demand delivery and digital commerce company founded in Bogotá in 2015, operating a multi-service super-app across nine Latin American countries at a valuation above $5 billion.

RaPPID trial

RaPPID trial (NCT03719170), a VA cluster-randomized pragmatic trial evaluating a national proton pump inhibitor de-prescribing program across 17 Veterans Integrated Service Networks, 9 intervention versus 8 control, with 12-month PPI prescribing as the primary outcome.

Rappin' for Jesus

Rappin' for Jesus is a viral 2013 YouTube music video of two Iowa pastors rapping about their faith, which drew nearly 100 million views.

Rapping

Rapping, or rap (MCing), is rhythmic rhymed speech performed over a beat; one of hip-hop's four elements, born in the 1970s Bronx with DJ Kool Herc, popularized by Sugarhill Gang's 1979 "Rapper's Delight", now the leading US streaming genre.

Rapport

Rapport: a quality interaction experience defined by mutual attentiveness, positivity, and coordination (Tickle-Degnen & Rosenthal, 1990). Central to professional interviews, therapy, and healthcare; 126 measures reviewed in 2024 show no agreed definition or validated common scale.