6,052 articles
Vopěnka's principle
Vopěnka's principle is a large cardinal axiom of set theory, formulated by Petr Vopěnka around 1960, stating there is no rigid proper class of graphs.
Voter model
The voter model is a stochastic interacting-particle model, introduced in 1973 and 1975, in which each vertex of a graph copies a random neighbor's opinion until consensus.
W. Edwards Deming
W. Edwards Deming (1900–1993) was an American statistician and management theorist whose statistical quality control teaching transformed Japanese industry after World War II and later reshaped American management.
W. T. Tutte
W. T. Tutte, born William Thomas Tutte, was a British-born Canadian mathematician and cryptanalyst who deduced the Lorenz cipher without seeing it, and proved foundational theorems in graph theory.
Wacław Sierpiński
Wacław Sierpiński, fully Wacław Franciszek Sierpiński, was a Polish mathematician (1882–1969) who worked in set theory and number theory, founded the journal Fundamenta Mathematicae, and gave his name to the Sierpiński triangle and carpet.
Wald test
The Wald test, also known as the Wald statistic, is a statistical test of hypotheses about model parameters, introduced by Abraham Wald in 1943 and widely used for regression coefficient p-values.
Wallace tree
A Wallace tree is a parallel digital circuit for summing binary numbers, combining bits in groups of three with carry-save adders, described by Chris Wallace in 1964.
Waring–Goldbach problem
The Waring–Goldbach problem is a question in additive number theory asking how few kth powers of primes suffice to represent large integers, merging Waring's problem with Goldbach's.
Waring's problem
Waring's problem, posed by Edward Waring in 1770, asks how many k-th powers suffice to represent every natural number as a sum; Hilbert proved a bound exists in 1909.
Warranty data analysis
Warranty data analysis is the modeling of warranty claims data to estimate field reliability, forecast future claims and costs, and detect product quality problems as they emerge.
Wason selection task
The Wason selection task is a four-card logic puzzle devised by psychologist Peter Wason in 1966, where most people fail to pick the cards that can test the rule.
WASPAS method
The WASPAS method is a multi-criteria decision-making method, presented by Zavadskas and colleagues in 2012, that ranks alternatives by combining weighted sum and weighted product scores.
Wasserstein metric
The Wasserstein metric, also called the Mallows distance and earth mover's distance, measures the minimum cost of moving probability mass from one distribution to match another, with roots in Monge's 1781 problem.
Water cycle algorithm
The water cycle algorithm (WCA) is a nature-inspired metaheuristic for constrained engineering optimization, introduced by Hadi Eskandar and colleagues in 2012, in which streams flow toward rivers and a sea.
Wave maps
A wave map is a map from Minkowski space into a Riemannian manifold that is a critical point of a natural action, the hyperbolic analog of a harmonic map.
Wavelet coherence analysis
Wavelet coherence analysis is a time-series method measuring the local correlation between two signals across time and frequency, revealing how their co-movement changes over scales in nonstationary data.
Wavelet packet decomposition
Wavelet packet decomposition is a signal processing method that recursively splits a signal into wavelet subbands at every frequency scale, forming a binary tree of coefficient sets.
Wavelet packet transform
The wavelet packet transform is a signal processing method that decomposes a signal into wavelet packets for a finer time-frequency representation than the discrete wavelet transform.
Wavelet transform
The wavelet transform, or wavelet transformation, is a linear mathematical transform that decomposes signals into components localized in both time and frequency, unlike the Fourier transform.
Weaire–Phelan structure
The Weaire–Phelan structure is a foam geometry proposed by physicists Denis Weaire and Robert Phelan in 1994, dividing space into equal-volume cells with the lowest known surface area.
Weak Galerkin method
The weak Galerkin method, introduced by Junping Wang and Xiu Ye in 2012, is a finite element method for numerically solving partial differential equations on general polytopal meshes.
Weak ordering
A weak ordering is a transitive and complete binary relation on a set, equivalent to a total preorder. It also refers to the weak Bruhat order on Coxeter groups.
Weak solution
A weak solution satisfies a partial differential equation through integral identities against test functions rather than pointwise differentiation, also called a generalized or distributional solution.
Weak topology
The weak topology on a Banach space X is the coarsest topology making every bounded linear functional in X continuous, introduced by von Neumann in 1929.
Weakly compact cardinal
A weakly compact cardinal is a large cardinal that is inaccessible and has the tree property, equivalent to satisfying the partition relation κ → (κ)²₂.
Weibull analysis
Weibull analysis is a statistical method that fits a Weibull distribution to failure-time data to estimate failure rates, lifetimes, and reliability, named after the Swedish mathematician Waloddi Weibull.
Weibull distribution
The Weibull distribution, also called the Rosin–Rammler distribution, is a continuous probability distribution with a power-law hazard, used to model failure times and wind speeds.
Weibull model
The Weibull model is a parametric probability model for failure times and other positive event times, used to estimate survival probabilities, failure rates, and life quantiles in reliability engineering.
Weierstrass function
The Weierstrass function, defined by a convergent trigonometric series, is continuous at every point yet differentiable at none; Karl Weierstrass presented it in 1872, and its graph is an early fractal.
Weight (representation theory)
In representation theory, a weight of a representation of a Lie algebra is a linear functional on a Cartan subalgebra recording the eigenvalues with which it acts on certain vectors.