Technology and the built world

Multiobjective evolutionary algorithm

A multiobjective evolutionary algorithm (MOEA) is a population-based optimization method that uses evolutionary search to approximate the Pareto front of problems with several conflicting objectives.

Multipath mitigation

Multipath mitigation is the set of antenna, correlator, estimator, and machine learning techniques that reduce GNSS positioning errors from signals reflecting off nearby surfaces, often the dominant error source in urban areas.

Multipath propagation

Multipath propagation occurs when a radio signal reaches a receiver along several reflected paths, causing fading, ghosting in television, and limits on mobile and microwave systems.

Multipath routing

Multipath routing is a networking method that forwards traffic between a source and destination over several paths at once, improving throughput, reliability, and load balancing; variants include ECMP and Multipath TCP.

Multipath TCP

Multipath TCP (MPTCP) is an extension of TCP that lets a single connection use multiple network paths at once, specified in RFC 8684 and used by Apple's Siri.

Multiphase buck converter

A multiphase buck converter is a DC-DC converter with staggered parallel buck stages, used in voltage regulator modules to power microprocessors at high current and low voltage.

Multiphoton lithography

Multiphoton lithography, also called two-photon polymerization or multiphoton absorption polymerization, is a laser technique that polymerizes a photoresist point by point, building free-form 3D structures with features below the diffraction limit.

Multiplan

Microsoft Multiplan was a spreadsheet application introduced in 1982 as Microsoft's first end-user program; it competed with VisiCalc and Lotus 1-2-3 before Excel replaced it.

Multiple (switchboard)

The multiple is the repetition of every subscriber's line in parallel jacks at every third position of a manual telephone switchboard, letting each operator reach every line.

Multiple dispatch

Multiple dispatch is a programming language mechanism that selects which method runs based on the runtime types of more than one argument, as in Julia and CLOS.

Multiple encryption

Multiple encryption is a cryptographic technique that applies a cipher several times with independent keys, best known through Triple DES, though double encryption gains little against meet-in-the-middle attacks.

Multiple exciton generation

Multiple exciton generation (MEG), also called carrier multiplication, is a process in which one absorbed high-energy photon creates two or more electron-hole pairs in a semiconductor.

Multiple independently targetable reentry vehicle

A multiple independently targetable reentry vehicle (MIRV) is a ballistic missile payload carrying several warheads, each aimed at a different target, first deployed by the United States in 1970.

Multiple inheritance

Multiple inheritance is the ability of a class to have more than one base class, so it inherits members from several direct parents, with the diamond problem as its best-known difficulty.

Multiple integrated laser engagement system

The Multiple Integrated Laser Engagement System (MILES) is a US Army tactical engagement simulation system, developed in the late 1970s, in which weapons fire coded laser "bullets" and worn detectors register hits.

Multiple kernel learning

Multiple kernel learning (MKL) is a machine learning method that learns a weighted combination of several kernel functions, letting each kernel represent a different data source.

Multiple patterning

Multiple patterning is a semiconductor lithography technique that creates chip features finer than one exposure can resolve, by repeating exposure and etch steps or using deposited spacers.

Multiple rocket launcher

A multiple rocket launcher, or multiple launch rocket system, is rocket artillery firing several rockets in salvo from one vehicle, introduced in World War II with the Soviet Katyusha.

Multiple signal classification

Multiple signal classification (MUSIC) is a subspace-based spectral estimation method invented by Ralph Schmidt in 1979 that estimates directions of arrival of wavefronts from sensor array data.

Multiple Spanning Tree Protocol

Multiple Spanning Tree Protocol (MSTP) is an IEEE 802.1Q protocol, standardized as 802.1s-2002, that maps multiple VLANs onto fewer spanning-tree instances, extending RSTP while interoperating with older STP bridges.

Multiple-alarm fire

A multiple-alarm fire, also called a three alarm fire, is one where a fire department dispatches additional predefined sets of engines and chiefs beyond the first alarm.

Multiple-arch dam

A multiple-arch dam is a concrete buttress dam in which thin arches span between buttresses, developed by John S. Eastwood from 1908 to save concrete.

Multiple-criteria decision analysis

Multiple-criteria decision analysis (MCDA), also called multi-criteria decision-making (MCDM), is a subfield of operational research that helps decision-makers choose, rank, or sort alternatives against several conflicting criteria.

Multiple-effect distillation

Multiple-effect distillation (MED) is a thermal desalination method that evaporates seawater in connected vessels at successively lower pressures, reusing latent heat across effects for low energy consumption.

Multiple-effect evaporator

A multiple-effect evaporator is a series of evaporator vessels in decreasing pressure, where vapor boiled off in one effect heats the next, reusing latent heat to save steam.

Multiple-input multiple-output equalization

Multiple-input multiple-output (MIMO) equalization is an adaptive filtering technique in which several input signals are jointly filtered into several outputs, separating mixed channels in coherent optical receivers.

Multiple-instance learning

Multiple-instance learning (MIL) is a weakly supervised machine learning method in which labels apply to whole bags of instances, introduced in 1997 for drug-activity prediction.

Multiplexer

A multiplexer, or data selector, selects one of several input signals and forwards it to a single output, or combines several signals into one composite signal for transmission.

Multiplexing

Multiplexing is the set of techniques for combining multiple information channels onto one shared transmission facility, such as a fiber or radio carrier, so they travel simultaneously.