Reduction, reduced, or reduce may refer to:

Science and technology

Chemistry

  • Reduction (chemistry), part of a reduction-oxidation (redox) reaction in which atoms have their oxidation state changed.
  • Organic redox reaction, a redox reaction that takes place with organic compounds
  • Ore reduction: see smelting

Computing and algorithms

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  • Reduction (complexity), a transformation of one problem into another problem
  • Reduction (recursion theory), given sets A and B of natural numbers, is it possible to effectively convert a method for deciding membership in B into a method for deciding membership in A?
  • Bit Rate Reduction, an audio compression method
  • Data reduction, simplifying data in order to facilitate analysis
  • Graph reduction, an efficient version of non-strict evaluation
  • L-reduction, a transformation of optimization problems which keeps the approximability features
  • Partial order reduction, a technique for reducing the size of the state-space to be searched by a model checking algorithm
  • Strength reduction, a compiler optimization where a function of some systematically changing variable is calculated more efficiently by using previous values of the function
  • Reduce (computer algebra system), a general-purpose computer algebra system geared towards applications in physics
  • Reduce (higher-order function), in functional programming, a family of higher-order functions that process a data structure in some order and build up a return value
  • Reduced instruction set computing, a CPU design philosophy favoring an instruction set reduced in size and complexity of addressing, to simplify implementation, instruction level parallelism, and compiling
  • Reduction operator, a type of operator that is commonly used in parallel programming to reduce the elements of an array into a single result.

Pure mathematics and statistics

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  • Reducible as the opposite of irreducible (mathematics)
  • Reduction (mathematics), the rewriting of an expression into a simpler form
  • Beta reduction, the rewriting of an expression from lambda calculus into a simpler form
  • Dimension reduction, the process of reducing the number of random variables under consideration
  • Lattice reduction, given an integer lattice basis as input, to find a basis with short, nearly orthogonal vectors
  • Subject reduction or preservation, a rewrite of an expression that does not change its type
  • Reduction of order, a technique for solving second-order ordinary differential equations
  • Reduction of the structure group, for a <math>G</math>-bundle <math>B</math> and a map <math>H \to G</math> an <math>H</math>-bundle <math>B_H</math> such that the pushout <math>B_H \times_H G</math> is isomorphic to <math>B</math>
  • Reduction system, reduction strategy, the application of rewriting systems to eliminate reducible expressions
  • Reduced form, in statistics, an equation which relates the endogenous variable X to all the available exogenous variables, both those included in the regression of interest (W) and the instruments (Z)
  • Reduced homology, a minor modification made to homology theory in algebraic topology, designed to make a point have all its homology groups zero
  • Reduced product, a construction that generalizes both direct product and ultraproduct
  • Reduced residue system, a set of φ(n) integers such that each integer is relatively prime to n and no two are congruent modulo n
  • Reduced ring, a ring with no non-zero nilpotent elements
  • Reduced row echelon form, a certain reduced row echelon form of a matrix which completely and uniquely determines its row space
  • Reduced word, in a free group, a word with no adjacent generator-inverse pairs
  • Variance reduction, a procedure used to increase the precision of the estimates that can be obtained for a given number of iterations

Medicine

Medical procedures

  • Lung volume reduction surgery, a treatment for chronic obstructive pulmonary disease
  • Selective reduction (or fetal reduction), the practice of reducing the number of fetuses in a multifetal pregnancy
  • Reduction (orthopedic surgery), a medical procedure to restore a fracture or dislocation to the correct alignment
  • Ventricular reduction, a type of operation in cardiac surgery
  • Cosmetic surgery:
  • Breast reduction
  • Jaw reduction

Other uses in medicine

  • Weight loss
  • In epidemiology:
  • Relative risk reduction, the absolute risk reduction by the control event rate
  • Absolute risk reduction, the decrease in risk of a given activity or treatment in relation to a control activity or treatment
  • Urea reduction ratio (URR), a dimensionless number used to quantify hemodialysis treatment adequacy

Physics

  • Dimensional reduction, the limit of a compactified theory where the size of the compact dimension goes to zero
  • Reduction criterion, in quantum information theory, a necessary condition a mixed state must satisfy in order for it to be separable
  • Reduced mass, the "effective" inertial mass appearing in the two-body problem of Newtonian mechanics
  • Reduced properties (pressure, temperature, or volume) of a fluid, defined based on the fluid's critical point

Other uses in science and technology

  • Lithic reduction, in Stone Age toolmaking, to detach lithic flakes from a lump of tool stone
  • Noise reduction, in acoustic or signal processing
  • Reduction drive, a mechanical device to shift rotational speed

Arts and media

  • Reducing (film), a 1931 American film
  • Reduction (music), music arranged for smaller resources (piano) for easier analysis or performance

Linguistics

  • Accent reduction, modifying one's foreign accent towards that of a native speaker
  • Vowel reduction, any change in vowel quality perceived as "weakening"
  • Vowel reduction in English
  • Relaxed pronunciation, slurring of syllables of common words
  • Definite article reduction, use of vowel-less forms of the English definite article in Northern England

Philosophy

  • Reductionism, a range of philosophical systems
  • Reductio ad absurdum, a form of argument in which a proposition is disproven by following its implications to an absurd consequence
  • Eidetic reduction, a technique in the study of essences in phenomenology whose goal is to identify the basic components of phenomena
  • Bracketing (phenomenology), also known as phenomenological reduction or transcendental reduction
  • Intertheoretic reduction, in philosophy of science, one theory makes predictions that perfectly or almost perfectly match the predictions of a second theory

Settlements

  • Reductions, settlements in Spanish America intended to control and Christianize Indians
  • Indian reductions in the Andes, settlements in the Andes to control and Christianize Indians

Other uses

  • Reduction (cooking), the process of thickening or intensifying the flavor of a liquid mixture such as a soup, sauce, wine, or juice by evaporation
  • Reduction (military), the siege and capture of a fortified place
  • Reduction (Sweden), a return to the Crown of fiefs that had been granted to the Swedish nobility
  • Reduce (waste), practices of minimizing waste
  • Reduction, Pennsylvania, unincorporated community, United States
  • Reduction in rank, in military law
  • Reduction to practice, in United States patent law, the embodiment of the concept of an invention
  • Ego reduction, predicated on the use of Sigmund Freud's concept of the ego
  • Reductions, resettlement of indigenous peoples during the Spanish colonization of the Americas

See also

  • Prevention (disambiguation)
  • Risk reduction (disambiguation)