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Operational Safety Case (UK CAA)
The Operational Safety Case (OSC) was the UK Civil Aviation Authority's document-based risk assessment for higher-risk drone operations, replaced by UK SORA in April 2025.
Operational semantics
Operational semantics is a formal method of defining programming languages by inference rules describing how programs execute on an abstract machine, introduced by Gordon Plotkin in 1981.
Operational space formulation
The operational space formulation, introduced by Oussama Khatib at Stanford in 1987, is a robot control framework that unifies motion and force control of a manipulator's end-effector.
Operational technology
Operational technology (OT) is the hardware and software that detects or causes changes in the physical world, running factories, power grids, water systems, and transit networks, distinct from information technology.
Operational transconductance amplifier
The operational transconductance amplifier (OTA) is an integrated-circuit amplifier whose output is a current proportional to the voltage between its inputs, with electronically tunable gain via a bias current.
Operational transformation
Operational transformation (OT) is a consistency-control technique for collaborative editing, introduced by Ellis and Gibbs in 1989, that transforms concurrent operations so replicas converge; it underpins Google Docs, Microsoft Office, and Overleaf.
Operations management
Operations management is the design, management, and improvement of systems that create goods or services, with decisions spanning processes, quality, capacity, inventory, and human resources.
Operations research
Operations research (OR), also called operational research, is an interdisciplinary field using mathematical models, optimization, and simulation to improve decisions, efficiency, and resource allocation in organizations.
Operations support system
An operations support system (OSS) is software a telecom enterprise uses to monitor, analyze, and manage its networks, covering provisioning, inventory, fault handling, and configuration.
Operator (computer programming)
In computer programming, an operator is a symbol or reserved word that performs a defined operation on one or more operands, such as the + in 3 + 4.
Operator assistance
Operator assistance, also called operator services, is telephone service in which an operator, human or automated, helps place or bill a call, now mainly collect, person-to-person, and international calls.
Operator inference
Operator inference (OpInf) is a non-intrusive scientific machine learning method that fits low-dimensional polynomial dynamical systems to simulation snapshots, introduced by Peherstorfer and Willcox in 2016.
Operator learning
Operator learning is a machine learning approach that trains neural networks to approximate mappings between infinite-dimensional function spaces, typically PDE solution operators, serving as fast surrogates in design and uncertainty quantification.
Operator overloading
Operator overloading is a programming language feature letting programmers define standard operators like + for their own types, central to C++, C#, Python, and Rust.
OPET (fuel company)
OPET is a Turkish fuel distribution company founded in 1992 by Fikret and Nurten Öztürk, half owned by Koç Group, with about 1,882 stations under the OPET and SUNPET brands.
Opifex
Opifex (Latin: maker, craftsman) names an open-source JAX/Flax NNX scientific machine learning framework by avitai, an indie app studio behind Return, and unrelated companies in Australia, Norway, Poland, India, the UK, and the US.
OPIR (satellite program)
OPIR, or Next Generation Overhead Persistent Infrared, is a United States Space Force program of missile-warning satellites built by Lockheed Martin and Northrop Grumman that will replace SBIRS.
OPIS Conway
OPIS Conway, also written Conway In-Well, is the daily spot price assessment for propane at the Conway, Kansas hub, published by OPIS and settling exchange-traded futures.
OPML
OPML, or Outline Processor Markup Language, is an XML-based format for outlines, developed by UserLand Software in 2000 and best known for exchanging RSS feed lists.
Opole power station
The Opole power station (Elektrownia Opole) is a hard coal-fired power station near Opole, Poland, operated by PGE with about 3,300 MW of capacity, among the largest coal plants in Poland.
Oppau explosion
The Oppau explosion, also called the Oppau disaster, destroyed much of the German town of Oppau on 21 September 1921, when blasting at a BASF fertilizer silo killed more than 500 people.
Oppenheimer pole
An Oppenheimer pole is a galvanized iron telegraph pole of three telescoping tubes, patented by German-born engineer Joseph Oppenheimer in 1867 and used across Australia's Overland Telegraph Line.
Oppo
Oppo, also known as OPPO Electronics, is a Chinese consumer electronics company founded in 2004 in Dongguan, Guangdong, and one of the world's largest smartphone makers.
Oppo Find X9
The Oppo Find X9 is an Android flagship smartphone released by OPPO in late 2025, with a Dimensity 9500 chip, 7025 mAh battery, and triple 50 MP Hasselblad cameras.
Opportunistic beamforming
Opportunistic beamforming is a multi-antenna wireless technique that varies antenna phases pseudorandomly and schedules users whose channels peak, introduced by Viswanath, Tse, and Laroia in 2002.
Opportunistic relaying
Opportunistic relaying is a cooperative wireless communication technique that selects the single best relay from several candidates using local channel measurements, achieving diversity gains on the order of the number of relays without multi-relay coordination.
Opportunistic scheduling
Opportunistic scheduling is a wireless network technique that assigns each time slot to the user whose channel conditions are momentarily best, exploiting multiuser diversity to raise total throughput.
Opportunistic spectrum access
Opportunistic spectrum access is a spectrum-sharing model in which unlicensed secondary users transmit in radio bands that licensed users are not using, exploiting temporarily vacant channels.
Opportunistic Wireless Encryption
Opportunistic Wireless Encryption (OWE) is a Wi-Fi security method that encrypts open networks without authentication, specified in RFC 8110 in 2017 and certified as Enhanced Open.
Opportunity (rover)
Opportunity, nicknamed Oppy, was a NASA Mars rover that landed in 2004 and found evidence of ancient water, operating for nearly 15 years against a planned 90-day mission.