42,772 articles
Inverse problem
An inverse problem, also called inverse theory or inverse modeling, is the task of determining the unknown causes of observed consequences using a forward model; it is usually ill-posed and handled by regularization or Bayesian inference.
Inverse Problems
Inverse Problems is an interdisciplinary peer-reviewed journal published by IOP Publishing since 1985, combining mathematical and experimental papers with theoretical, numerical, and practical approaches to inverse problems.
Inverse problems in plasma diagnostics
Inverse problems in plasma diagnostics reconstruct unmeasurable plasma quantities, such as emissivity or current density, from indirect detector measurements by inverting an ill-posed forward model.
Inverse scattering
Inverse scattering is a mathematical method that reconstructs an object's shape or a medium's refractive index and scattering potential from measurements of scattered waves, a nonlinear and ill-posed problem.
Inverse scattering transform
The inverse scattering transform, also called the nonlinear Fourier transform, solves integrable nonlinear PDEs like the KdV equation by converting them into linear scattering problems.
Inverse seesaw mechanism
The inverse seesaw mechanism is a neutrino mass model, proposed by Mohapatra and Valle in 1986, in which small neutrino masses come from a small lepton-number-violating parameter.
Inverse semigroup
An inverse semigroup is a semigroup in which every element has a unique inverse, the algebraic structure capturing partial symmetries, defined independently by Vagner and Preston in the 1950s.
Inverse transform sampling
Inverse transform sampling, also called inversion, generates random samples from a probability distribution by applying the inverse of its cumulative distribution function to a uniform random number.
Inverse trigonometric functions
The inverse trigonometric functions, also known as cyclometric or arc functions, are six functions that invert the sine, cosine, and tangent to return the angle for a given value.
Inverse vulcanization
Inverse vulcanization is a copolymerization process, introduced by Jeffrey Pyun in 2013, in which molten elemental sulfur is crosslinked by organic molecules to form stable polymers.
Inverse-gamma distribution
The inverse-gamma distribution, or inverted gamma distribution, is a continuous probability distribution obtained as the reciprocal of a gamma-distributed variable, used mainly as a conjugate prior for a normal variance.
Inverse-square law
The inverse-square law is the physical rule that a quantity spreading from a point source, like gravity or light, falls off as the square of the distance.
Inversion (meteorology)
In meteorology, an inversion, or temperature inversion, is an atmospheric layer in which air temperature rises with height, acting as a lid that traps fog, smoke, and pollutants.
Inversion (symmetry)
Inversion is the symmetry operation reflecting every point through a central point, mapping (x, y, z) to (−x, −y, −z); a crystal with it is centrosymmetric, symbol 1̄.
Inversion recovery
Inversion recovery is an MRI pulse sequence in which a 180° pulse inverts magnetization, whose recovery yields T1; choosing the delay nulls a tissue's signal, as in STIR and FLAIR.
Inversion tectonics
Inversion tectonics is the geological process in which a basin formed by extension is later shortened, so its controlling faults reverse movement and the basin fill is uplifted.
Inversion temperature
The inversion temperature of a gas is the temperature at which the Joule–Thomson coefficient changes sign, so expansion below it cools and above it heats the gas, governing liquefaction.
Inversion theorem (probability theory)
An inversion theorem in probability theory recovers a probability distribution, its density, or mass function from a transform, most famously via the Lévy inversion theorem for characteristic functions.
Inverted pendulum
The inverted pendulum, also known as the cart and pole, is a pendulum with its mass above its pivot, making it unstable and a standard benchmark in control theory since 1960.
Invertible matrix
An invertible matrix, also called a non-singular matrix, is a square matrix with an inverse that multiplies it to give the identity; such an inverse exists exactly when the determinant is nonzero.
Involute
An involute of a plane curve is the curve traced by the end of a taut string unwound from it, described by Christiaan Huygens in 1673.
Involution (mathematics)
An involution in mathematics is a function that is its own inverse, so applying it twice gives back the original; examples include negation, reciprocals, and complex conjugation.
INVOLVE
INVOLVE was the United Kingdom's national advisory group for public involvement in health and social care research, established in 1996 and funded by the NIHR until 2020.
Io (moon)
Io, also known as Jupiter I, is the innermost of Jupiter's Galilean moons and the most volcanically active world in the solar system, with about 400 active volcanoes.
Io (Ἰώ)
Io is Jupiter's innermost Galilean moon, slightly larger than Earth's Moon, and the most volcanically active body in the Solar System, with roughly 400 active volcanoes.
Ioannis George Kevrekidis
Ioannis George Kevrekidis, known as Yannis Kevrekidis, is a Greek-born chemical engineer and applied mathematician at Johns Hopkins University, known for pioneering equation-free multiscale computation.
Ioannis Iliopoulos
Ioannis (John) Iliopoulos, born 1940 in Kalamata, Greece, is a Greek theoretical physicist who co-invented the GIM mechanism, which introduced the charm quark into weak-interaction theory.
Iobenguane
Iobenguane, also called metaiodobenzylguanidine or MIBG, is a norepinephrine analog radiolabeled with iodine: the iodine-123 form images tumors, and iodine-131 iobenguane, Azedra, treats pheochromocytoma and paraganglioma.
Iodide
Iodide is the anion I⁻, the reduced ionic form of iodine that living organisms handle: the thyroid concentrates it from food and iodized salt to make thyroid hormones.
Iodine
Iodine (Jodium) is the chemical element with symbol I and atomic number 53, a halogen best known for its role in thyroid hormones, medical imaging, and disinfection.