Technology and the built world

Line card

A line card is a printed circuit board in a telephone exchange that provides the electronic interface between one subscriber's line and the switching system.

Line level

Line level is the nominal signal strength used to carry audio between components like mixers and amplifiers, at +4 dBu professional or −10 dBV consumer level.

LINE MAN

LINE MAN is a Thai on-demand services app launched by LINE Corporation, offering food and grocery delivery, taxi, and messenger services; it merged with Wongnai in 2020.

LINE Music

LINE Music is a Japanese subscription music streaming service launched by LINE Corporation in 2015, available only in Japan and known for sharing songs in LINE chats.

Line of action

The line of action, also called the pressure line or generating line, is the common normal to two meshing gear teeth at their point of contact.

Line of balance

Line of balance is a graphical scheduling method for repetitive work, such as housing projects and high-rise floors, in which each trade is a sloped line showing its production rate.

Line Operations Safety Audit

The Line Operations Safety Audit (LOSA) is a voluntary, non-punitive observational program in which trained peer observers ride flight decks and record how airline crews manage threats and errors.

Line pack, also written linepack, is gas stored within a pipeline at pressure and released by pressure reduction when demand exceeds supply, giving gas networks built-in short-term storage that electricity lines lack.

Line segment detector

A line segment detector is a computer vision algorithm that finds straight contours in images; the best-known example is LSD, a linear-time, parameter-free method published in 2009.

Line shaft

A line shaft, also called line shafting, is a long rotating overhead shaft whose pulleys and belts carried power from one engine to dozens of factory machines.

LINE Stickers

LINE Stickers are illustrations or images sent in LINE chats to convey greetings or emotions, sold as themed packs featuring official characters and independent artists' work.

Line-commutated converter

A line-commutated converter (LCC) is a power-electronic converter that changes power between AC and DC using thyristor valves, the conventional technology dominating long-distance bulk HVDC transmission.

Line-crossing ceremony

The line-crossing ceremony, also called Crossing the Line, is a naval initiation rite performed when a ship crosses the equator, with first-time crossers initiated as shellbacks.

Line-edge roughness

Line-edge roughness (LER) is the deviation of a lithographically patterned line edge from its ideal straight form, measured as rms roughness, and a growing limit in semiconductor manufacturing.

Line-oriented flight training

Line-oriented flight training (LOFT) is a simulator-based airline training method in which a flight crew flies an uninterrupted, real-time scenario to develop coordination and decision-making.

Line-scan imaging

Line-scan imaging is a machine vision technique in which a camera captures an image one line at a time as the object moves, suiting continuous web inspection.

LineageOS

LineageOS is a free and open-source operating system for mobile devices, based on Android and forked from CyanogenMod in 2016 after Cyanogen Inc. shut down.

Linear (software)

Linear is a web-based issue tracking and product development system for software teams, founded in 2019, known for a fast, keyboard-driven interface, and used by more than 40,000 companies.

Linear actuator

A linear actuator is a device that creates motion in a straight line, converting energy such as motor rotation, compressed air, or hydraulic fluid into push or pull force.

Linear amplifier

A linear amplifier is an amplifier whose output faithfully reproduces its input waveform; in radio practice it uses Class A or AB operation for AM and digital signals.

Linear attention

Linear attention is a family of approximations to transformer self-attention, introduced by Katharopoulos et al. in 2020, that replaces softmax with kernel feature maps to reduce computation from quadratic to linear.

Linear classifier

A linear classifier assigns a class label by taking the sign of a weighted sum of feature values, and is the standard fast method for text classification.

Linear complementarity problem contact formulation

The linear complementarity problem contact formulation writes rigid-body contact dynamics with Coulomb friction as an LCP; the Anitescu-Potra version of 1997 was the first proved solvable for any contact configuration.

Linear compressor

A linear compressor is a gas compressor in which a linear electric motor drives the piston directly, without a crank mechanism, first commercialized by LG in 2001.

Linear congruential generator

A linear congruential generator (LCG) is a pseudorandom number generator defined by the recurrence X(n+1) = (aXn + c) mod m, proposed by Lehmer in 1951.

Linear cryptanalysis

Linear cryptanalysis is a known-plaintext attack that recovers bits of a cipher's key from linear approximations; Matsui used it to break full DES in 1994.

Linear filter

A linear filter transforms a signal or image by convolution with a small array of weights called a kernel, to smooth, sharpen, denoise, detect edges, or undo blur.

Linear Fresnel reflector

A linear Fresnel reflector (LFR) is a concentrating solar power collector in which long, parallel mirror strips reflect sunlight onto a fixed elevated receiver, trading optical efficiency for lower cost.

Linear friction welding

Linear friction welding is a solid-state joining process that rubs two workpieces together under compressive force, generating frictional heat that bonds them without melting; it is used mainly for aircraft engine blisks.