All articles starting with R
22,461 articles
Random vibration
Random vibration is vibration whose amplitude and frequency vary unpredictably in time, described statistically by power spectral density and used in engineering to simulate launch, transport, and turbulent-flow environments.
Random vibration analysis
Random vibration analysis is a probabilistic structural-dynamics method that predicts how structures respond to random excitation described by a power spectral density, yielding RMS stresses and fatigue damage.
Random walk
A random walk, also called a drunken walk, is a stochastic process describing a path formed by successive random steps, used to model diffusion and fluctuation.
Random walk hypothesis
The random walk hypothesis is the finance claim that successive price changes of a traded asset are statistically independent, so past movements cannot predict future ones.
Random-access machine
A random-access machine (RAM) is an abstract model of computation: a program operating on an array of registers, any of which can be read or written directly by index.
Random-access memory
Random-access memory (RAM) is read/write memory in which any bit is accessed as fast as any other, usually volatile semiconductor chips holding data a processor is using.
Random-effects meta-analysis
Random-effects meta-analysis is a statistical method for combining effect estimates from multiple studies assumed to vary, following a distribution with a mean and a between-study variance.
Random-field Ising model
The random-field Ising model is a lattice spin model in which ferromagnetic Ising spins couple to frozen random fields, introduced by Imry and Ma in 1975 and central to disordered systems.
Random-matrix theory of quantum transport
Random-matrix theory of quantum transport describes scattering in mesoscopic systems like quantum dots by ensembles of random scattering matrices, yielding universal conductance averages and fluctuations.
Randomization (clinical trials)
Randomization, also called simple or complete randomization, is the procedure in clinical trials that assigns participants to treatment groups by chance, preventing selection bias in enrollment.
Randomization inference
Randomization inference, also known as permutation inference, is a statistical method for testing treatment effects in experiments by computing a test statistic's distribution over all possible random assignments, requiring no distributional assumptions.
Randomization test
A randomization test is a statistical significance test that evaluates a treatment effect by repeatedly reassigning group labels at random, giving exact Type I error control without distributional assumptions.
Randomized algorithm
A randomized algorithm is an algorithm whose steps depend on random bits, split into Las Vegas algorithms, always correct, and Monte Carlo algorithms, which may err.
Randomized benchmarking
Randomized benchmarking is an experimental protocol that estimates the average error rate of quantum gates by fitting how survival probability decays over random gate sequences, avoiding dependence on state preparation and measurement errors.
Randomized block design
A randomized block design is a statistical experimental design that groups similar units into blocks and randomizes treatments within each block, removing block-to-block variation from experimental error.
Randomized compiling
Randomized compiling (RC) is a quantum computing protocol, proposed by Wallman and Emerson in 2015, that inserts random single-qubit gates to turn coherent errors into stochastic Pauli errors.
Randomized controlled trial
Randomized controlled trial (RCT), also called randomized clinical trial: a study assigning participants by chance to treatment and control groups; the gold standard for testing treatment safety and efficacy, reported under CONSORT.
Randomized experiment
A randomized experiment is a study design in which participants are assigned to treatment or control groups by a random mechanism, allowing causal effects to be estimated.
Randomized rounding
Randomized rounding is a technique in combinatorial optimization that turns a fractional linear programming solution into an integer one, introduced by Raghavan and Thompson in 1987.
Randomized singular value decomposition
The randomized singular value decomposition (randomized SVD, or RSVD) is a numerical linear algebra algorithm that computes an approximate truncated SVD of a large matrix using random sampling.
Randomized smoothing
Randomized smoothing is a machine learning technique that turns an arbitrary classifier into a smoothed classifier with a certified robustness guarantee against adversarial perturbations, proven at ICML 2019.
Randomized storage (warehousing)
Randomized storage, also called random or scattered storage, is a warehouse policy of placing items in any open location, trading longer picker travel for better space use.
Randomized trial
A randomized trial is an experimental study in which chance assigns participants to interventions, making groups comparable; the randomized controlled trial is the standard form used in clinical research.
Randomness
Randomness is the absence of exact predictability in the outcome of a process, modeled by assigning probabilities to each possible outcome and quantified by entropy.
Randomness test
A randomness test is a statistical procedure judging whether an ordered data sequence was produced randomly, detecting trends, oscillation, and autocorrelation; common examples include the Wald–Wolfowitz runs test.
Randonautica
Randonautica (Randonauts app) is a quantumly generated adventure app sending users to random GPS coordinates after setting an intention, testing Mind-Matter Interaction via Attractor, Void, Power, and Blind Spot points.
Randstad
Randstad: Dutch polycentric urban region around Amsterdam, Rotterdam, The Hague, and Utrecht, named by KLM founder Albert Plesman in 1938, ringed around the Green Heart, fourth largest European metro economy.
Randstad N.V.
Randstad N.V. is a Dutch human resources and staffing multinational founded in 1960 by Frits Goldschmeding, providing temporary staffing, permanent placement, and outsourced HR services in 39 markets.
RandstadRail
RandstadRail is a light rail network in the Rotterdam–The Hague conurbation of the Netherlands, created by converting former Dutch Railways suburban lines and opened in stages during 2006 and 2007.
Randwick
Randwick is a south-eastern Sydney suburb named by Simeon Pearce after Randwick, Gloucestershire. Its municipality was proclaimed 22 February 1859, the second oldest LGA in NSW, and it hosts Randwick Racecourse and Prince of Wales Hospital.