All articles starting with M

Multijunction solar cell

A multijunction solar cell is a photovoltaic device that stacks several semiconductor junctions, each tuned to a different part of the solar spectrum, reaching record efficiencies above 45%.

Multilateral Agreement on Investment

Multilateral Agreement on Investment (MAI): OECD treaty negotiations launched May 1995 for high-standard investment liberalization and protection; drafted through 1998, suspended October 1998 after France withdrew; no agreement concluded.

Multilateral Convention to Implement Tax Treaty Related Measures to Prevent Base Erosion and Profit Shifting

The Multilateral Instrument (BEPS MLI, OECD/LEGAL/0432) is a multilateral tax treaty adopted 24 November 2016 under OECD/G20 BEPS Action 15, in force 1 July 2018, that modifies existing bilateral tax treaties to counter treaty abuse and improve dispute resolution.

Oct 10, 2026

Multilateral Debt Relief Initiative

The Multilateral Debt Relief Initiative (MDRI) is a 2005 arrangement under which the IMF, IDA, and African Development Fund cancel 100 percent of claims on qualifying poor countries.

Oct 10, 2026

Multilateral Investment Guarantee Agency

The Multilateral Investment Guarantee Agency (MIGA) is the World Bank Group's political risk insurer, established in 1988, which has issued over $100 billion in guarantees protecting investors in developing countries.

Multilateral treaty

A multilateral treaty is a written international agreement between more than two states, governed by international law and defined in the 1969 Vienna Convention on the Law of Treaties.

Multilateralism

Multilateralism is a form of international relations in which three or more states coordinate their conduct on generalized principles, rather than through bilateralism or unilateralism.

Multilateration

Multilateration is a positioning technique that determines an object's location from time-based signal measurements at multiple stations, notably used for air traffic surveillance of aircraft.

Multilayer insulation (cryogenics)

Multilayer insulation, also called superinsulation, is a thermal insulation system of many reflective shields separated by spacers under high vacuum, used on spacecraft, cryogenic transfer lines, and liquid hydrogen storage.

Multilayer mirror

A multilayer mirror is an optical element for X-ray and extreme ultraviolet light, made of tens to hundreds of alternating layers that reflect by Bragg constructive interference, used in EUV lithography.

Multilayer perceptron

A multilayer perceptron (MLP) is a feedforward neural network whose units compute weighted sums plus biases through nonlinear activations, trained by backpropagation; it is the quintessential deep learning model.

Multilevel feedback queue

The multilevel feedback queue (MLFQ) is a CPU scheduling algorithm that moves processes between priority queues by observed behavior, demoting CPU-bound jobs and boosting interactive ones.

Multilevel inverter

A multilevel inverter is a power converter that combines several DC voltage levels into a stepped AC waveform with lower harmonic distortion than a conventional two-level inverter.

Multilevel logistic regression

Multilevel logistic regression is a regression method for binary outcomes that adds normally distributed random effects at several levels, such as patients within hospitals, to model clustering.

Multilevel meta-analysis

Multilevel meta-analysis is a statistical method combining effect sizes from multiple studies while modeling their nested structure, such as several effect sizes from the same study, using hierarchical random-effects models.

Multilevel model

A multilevel model, also called hierarchical linear modeling, is a regression model for nested data, such as pupils within schools, estimating effects at each level.

Multilevel Monte Carlo

Multilevel Monte Carlo (MLMC) is a variance reduction technique, introduced by Michael Giles in 2008, that estimates expectations by simulation through a telescoping sum of corrections across levels of increasing accuracy.

Multilevel regression

Multilevel regression, also called hierarchical linear modeling, is a statistical method for fitting regression models to nested or clustered data such as students within schools.

Multilevel regression and poststratification

Multilevel regression and poststratification (MRP, sometimes Mister P) is a statistical method introduced by Gelman and Little in 1997 that estimates state-level opinion from a single national poll.

Multilinear algebra

Multilinear algebra is the branch of algebra dealing with multilinear maps between vector spaces, whose central objects are tensors; it underlies tensor calculus, differential forms, and tensor decompositions used in data analysis.

Multilingual BERT

Multilingual BERT, or mBERT, is a single BERT model pretrained by Google on Wikipedia text in 104 languages with no cross-lingual signal, released in late 2018.

Multilingual jailbreak

A multilingual jailbreak is an attack on a large language model that phrases harmful requests in low-resource languages, exploiting safety training concentrated in English, with defenses including English-proxy prompting.

Multilingual LibriSpeech

Multilingual LibriSpeech (MLS) is an open-source corpus of transcribed read speech released by Facebook AI in 2021, containing over 50,000 hours of LibriVox audiobook audio in eight languages.

Multilingual pretraining corpora

Multilingual pretraining corpora are web-scale text collections that give foundation models training signal in languages other than English, built by filtering and deduplicating web crawls; open examples include MADLAD-400, CulturaX, HPLT, and mOSCAR.