61,984 articles
Explosively formed penetrator
An explosively formed penetrator (EFP), also called a self-forging fragment or platter charge, is a warhead that deforms a metal liner into a kinetic slug.
Expo (software)
Expo is a framework and set of tools for building React Native applications, letting developers write one JavaScript or TypeScript project that runs natively on Android, iOS, and web.
Exponential backoff
Exponential backoff is a retry strategy in which the delay between attempts grows by a constant factor after each failure, usually combined with jitter to prevent synchronized retries.
Exponential search
Exponential search, also called doubling search or galloping search, is a search algorithm for sorted arrays, described by Jon Bentley and Andrew Yao in 1976.
Export of cryptography from the United States
The export of cryptography from the United States has been controlled since the Cold War, first under ITAR as a munition and since 1996 under the Commerce Department's regulations.
Exposed node problem
The exposed node problem, also called the exposed terminal problem, is a wireless networking issue in which a station defers transmission although it would not interfere, reducing throughput.
Exposure (photography)
Exposure, also known as photographic exposure, is the amount of light reaching film or a digital sensor in photography, controlled by shutter speed, aperture, and ISO.
Express mail
Express mail is the fastest class of postal delivery service, offered domestically by national posts and internationally as Express Mail Service (EMS), available in around 200 countries.
Express Oil Pipeline System
The Express Oil Pipeline System, also known as Line 40A, is a crude oil pipeline carrying Western Canadian crude from Hardisty, Alberta, to Casper, Wyoming, since 1997; it connects there with the Platte Pipeline.
Express trains in India
Express trains in India are the principal long-distance passenger services of Indian Railways, stopping at major towns and including named trains like the Rajdhani and Shatabdi.
Express.js
Express.js is a fast, unopinionated, minimalist web application framework for Node.js, created by TJ Holowaychuk in 2010, whose middleware and routing model makes it the most widely used Node.js framework.
ExpressCard
ExpressCard, also known as Newcard, is a laptop expansion-card standard unveiled by PCMCIA in 2003 as the successor to PC Card, carrying PCI Express and USB 2.0 signals.
Expressed sequence tag
An expressed sequence tag (EST) is a short single-pass sequence read from a cDNA clone, typically under 1,000 base pairs, that tags genes expressed in the sampled tissue.
Expression (computer science)
An expression in computer science is a combination of variables, values, operators, and function calls that is evaluated to produce a value, such as 2+3 yielding 5.
Expressive motion
Expressive motion in robotics is the use of a robot's own body movement, rather than a separate display, to communicate emotion, mood, or task status to people.
ExpressLRS
ExpressLRS is an open-source radio control link that sends pilot commands to model aircraft and telemetry back, built for low latency and long range, mainly for FPV drones.
ExpressVPN
ExpressVPN is a commercial virtual private network service founded in 2009, registered in the British Virgin Islands and owned by Kape Technologies since 2021, with a no-logs policy.
Expressways of India
Expressways of India are the country's highest class of road: fully access-controlled highways whose operational network grew from 93 km in 2014 to 3,052 km by 2026.
Expressways of Singapore
The expressways of Singapore are ten limited-access, dual-carriageway roads without traffic lights, including the 42.8 km Pan Island Expressway, first planned in the 1971 Concept Plan.
Expro Group
Expro Group is an international energy services company serving oil, gas, and geothermal operators in more than 50 countries, founded in 1973 and listed on the NYSE under XPRO.
EXPSPACE
EXPSPACE (exponential space) is the complexity class of decision problems solvable by a deterministic Turing machine using memory bounded exponentially in input length; equivalence of regular expressions with squaring requires it.
EXPTIME
EXPTIME, also written EXP, is the complexity class of decision problems solvable by a deterministic Turing machine in time 2^(n^k); it strictly contains P, and its complete problems include generalized chess, checkers, and Go.
Exsolution in perovskite catalysts
Exsolution in perovskite catalysts is the in situ growth of metal nanoparticles on a perovskite oxide surface, where socketed particles resist agglomeration, coking, and poisoning in fuel cells and electrolysers.
Ext2
Ext2, also called second extended file system or Ext2fs, is a Linux filesystem released in January 1993 by Rémy Card, Theodore Ts'o, and Stephen Tweedie, once the predominant Linux filesystem.
Ext3
Ext3, or the third extended filesystem, is a journaling filesystem for Linux released in 1999 by Stephen Tweedie as ext2 plus a journal, and long the default in most distributions.
Ext4
Ext4, also called the fourth extended file system, is the journaling Linux file system evolved from ext3, which records file data in extents and supports files up to 16 TiB.
Extended aeration
Extended aeration is a low-rate modification of the activated sludge wastewater treatment process with long aeration times, most commonly built as oxidation ditches or package plants serving small communities.
Extended ASCII
Extended ASCII (EASCII) is a loose term for 8-bit encodings that add accented letters, currency symbols, and graphics above 7-bit ASCII, in incompatible families like ISO 8859 and Windows code pages.
Extended attributes
Extended attributes, abbreviated xattrs, are name:value pairs that filesystems store with files and directories to hold metadata such as access control lists and security labels.
Extended Display Identification Data
Extended Display Identification Data (EDID) is a VESA metadata format, introduced in 1994, that a display uses to tell a video source its manufacturer, timings, and capabilities.