All articles starting with P
28,818 articles
Perceptive Xontogeny Venture
Perceptive Xontogeny Venture (PXV) is the early-stage biotech venture capital platform of New York's Perceptive Advisors, which raised funds of $210 million in 2018 and $515 million in 2021.
Percepto
Percepto is an Israeli technology company, founded in 2014, that provides autonomous drone-in-a-box inspection and monitoring systems for energy, utility, oil and gas, and mining sites.
Perceptron
The perceptron is a linear binary classifier described by Frank Rosenblatt in 1957, which learns by adjusting its weights only when it misclassifies a training example.
Perceptual evaluation of speech quality
Perceptual evaluation of speech quality (PESQ) is an ITU-T standard, P.862, that predicts perceived speech quality by comparing a degraded signal against a clean reference.
Perceptual hashing
A perceptual hash is a short fingerprint of an image, video, or audio file that stays similar under resizing, compression, and noise, enabling near-duplicate detection and media retrieval.
Perceval, the Story of the Grail
Perceval, the Story of the Grail (Perceval ou le Conte du Graal) is an unfinished Old French verse romance by Chrétien de Troyes and the earliest known story of the Holy Grail.
Perch
Perch: true perch are Perca fluviatilis and P. flavescens of the family Percidae (over 190 holarctic freshwater species); the name also covers unrelated fish like Sebastes alutus and Morone americana.
Perche (unit)
The perche was a French pre-metric unit of length used for measuring land, equal to 3 toises or 18 French feet, though it varied by province.
Perched water table
A perched water table is a local zone of saturation sitting above the regional water table, held there by a low-permeability layer and separated from the main groundwater by unsaturated soil.
Percheron
The Percheron is a French draft horse breed from the Perche region of northern France, now bred on every continent and used for driving, farm, and forestry work.
Percheron Capital
Percheron Capital is a San Francisco private equity firm founded in 2020 by Chris Collins and Chris Lawler, investing in North American essential services businesses.
Perchlorate
Perchlorate is the anion ClO4−, the conjugate base of perchloric acid, best known as a rocket propellant oxidizer and a drinking water contaminant affecting the thyroid.
Perchlordecone
Perchlordecone, also called chlordecone or Kepone (CAS 143-50-0), is a banned persistent organochlorine insecticide, C10Cl10O, tied to the 1975 Hopewell worker poisonings and long-term soil, water, and prostate cancer contamination in the French West Indies.
Perchloric acid
Perchloric acid (HClO4), also called hydrogen perchlorate, is the strongest common oxyacid of chlorine, a strong acid and powerful oxidizer that becomes explosive when concentrated above 72%.
Perchloroethylene
Perchloroethylene, also called perc, is a nonflammable chlorinated solvent used chiefly in dry cleaning and metal degreasing, the leading US dry cleaning solvent since the 1940s.
Perchta
Perchta, also Berchta or Percht, is the Alpine and southern German folklore figure of the Twelve Days between Christmas and Epiphany, who rewards the diligent and slits open the lazy's bellies; leader of the masked Perchten and counterpart of Frau Holle.
Perchta Corona
Perchta Corona is a 500 km diameter corona on Venus at 17.0°N, 234.5°E, named 1994 for a German fertility goddess, lying along Hecate Chasma in Ulfrun Regio with a central plateau and radiating graben system.
Perci Cendaña
Percival "Perci" Cendaña is a Filipino politician, Akbayan party-list representative in the Philippine House of Representatives since September 2024, former National Youth Commission commissioner, author of the Kian Bill and SOGIESC anti-discrimination measure.
Percidae
Percidae, the perch family (Rafinesque, 1815), is a Northern Hemisphere freshwater fish family in Perciformes with 11 genera and about 248 species, including perch, zander, walleye, ruffe, and the species-rich North American darters.
Perciformes
Perciformes, perch-like fishes, an order of ray-finned fishes containing perches, groupers, tunas, gobies, and wrasses; once the largest vertebrate order with 160 families, redefined monophyletically in 2013 to 61 families within Eupercaria.
Percilla Bejano
Percilla Bejano (Percilla Román/Lauther, 1911–2001), the Monkey Girl and Bearded Lady, was a Puerto Rican-born sideshow performer with hypertrichosis and hyperdontia who married the Alligator Skin Boy, Emmitt Bejano, in 1938 and appeared in Carny (1980).
Percipient.ai
Percipient.ai is a private American artificial-intelligence company founded in 2017 and based in Santa Clara, California, whose Mirage platform applies computer vision and machine learning to national-security intelligence analysis.
Percipio XYZ
Percipio XYZ, also known as 图漾科技 or Shanghai Percipio Technology, is a Chinese company founded in Shanghai in 2015 that makes 3D depth cameras for industrial automation, logistics, and mobile robots.
Percival
Percival (Perceval, Parzival) is the original Grail knight of Arthurian legend, first appearing in Chrétien de Troyes's unfinished Conte du Graal and Wolfram's Parzival, later displaced by Galahad.
Percival Bailey
Percival Bailey (1892–1973) was an American neurosurgeon and neuropathologist best known for the first histological classification of brain gliomas with Harvey Cushing and for showing in 1921 that diabetes insipidus originates in the hypothalamus.
Percival Everett
Percival Everett (born 1956) is an American novelist, poet, and USC English professor, author of Erasure, The Trees, Dr. No, and James, the 2024 National Book Award and 2025 Pulitzer Prize-winning retelling of Huckleberry Finn.
Percival Lowell
Percival Lowell (1855–1916) was an American astronomer and businessman from Boston who founded Lowell Observatory in Flagstaff, Arizona, in 1894 and promoted the theory of Martian canals.
Percival Molson Memorial Stadium
Percival Molson Memorial Stadium, McGill Graduates' Stadium, Montreal Alouettes and McGill home field; opened 1915, smallest CFL stadium, about 23,000 seats on Mount Royal.
Percolation
Percolation is a mathematical model of random media, introduced by Broadbent and Hammersley in 1957, centered on a critical threshold where isolated clusters become system-spanning.
Percolation model
The percolation model is a mathematical and simulation method studying how connected clusters form and grow in random media, with a critical threshold p_c marking the onset of system-spanning clusters.