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Narrowing By Exclusion Of Dependent Values
Narrowing may refer to: *Narrowing (computer science), a type of algorithm for solving equations between symbolic expressions **Narrowing of algebraic value sets, a method for the elimination of values from a solution set which are inconsistent with the equations being solved *Narrowing (historical linguistics), a type of semantic change *Collisional narrowing of a spectral line due to collisions of the emitting species *Motional narrowing of a resonant frequency due to the inhomogeneity of the system averaging out over time *Perceptual narrowing, a process in brain development *Q-based narrowing, a concept in pragmatics *Stenosis, the narrowing of a blood vessel or other tubular organ See also *Narrow (other) {{Disambiguation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Narrowing (computer Science)
In logic and computer science, specifically automated reasoning, unification is an algorithmic process of solving equations between symbolic expression (mathematics), expressions, each of the form ''Left-hand side = Right-hand side''. For example, using ''x'',''y'',''z'' as variables, and taking ''f'' to be an uninterpreted function, the Singleton (mathematics), singleton equation set is a syntactic first-order unification problem that has the substitution as its only solution. Conventions differ on what values variables may assume and which expressions are considered equivalent. In first-order syntactic unification, variables range over first-order terms and equivalence is syntactic. This version of unification has a unique "best" answer and is used in logic programming and programming language type system implementation, especially in Hindley–Milner based type inference algorithms. In higher-order unification, possibly restricted to higher-order pattern unification, terms may ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Narrowing Of Algebraic Value Sets
Like logic programming, narrowing of algebraic value sets gives a method of reasoning about the values in unsolved or partially solved equations. Where logic programming relies on resolution, the algebra of value sets relies on narrowing rules. Narrowing rules allow the elimination of values from a solution set which are inconsistent with the equations being solved. Unlike logic programming, narrowing of algebraic value sets makes no use of backtracking. Instead all values are contained in value sets, and are considered in parallel. The approach is also similar to the use of constraints in constraint logic programming, but without the logic processing basis. Probabilistic value sets is a natural extension of value sets to deductive probability. The value set construct holds the information required to calculate probabilities of calculated values based on probabilities of initial values. History Early programming languages were imperative. These implement functionali ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Narrowing (historical Linguistics)
Semantic change (also semantic shift, semantic progression, semantic development, or semantic drift) is a form of language change regarding the evolution of word usage—usually to the point that the modern meaning is radically different from the original usage. In diachronic (or historical) linguistics, semantic change is a change in one of the meanings of a word. Every word has a variety of senses and connotations, which can be added, removed, or altered over time, often to the extent that cognates across space and time have very different meanings. The study of semantic change can be seen as part of etymology, onomasiology, semasiology, and semantics. Examples in English * Awful – Literally "full of awe", originally meant "inspiring wonder (or fear)", hence "impressive". In contemporary usage, the word means "extremely bad". * Awesome – Literally "awe-inducing", originally meant "inspiring wonder (or fear)", hence "impressive". In contemporary usage, the word means "ext ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Collisional Narrowing
In spectroscopy, the Dicke effect, also known as Dicke narrowing or sometimes collisional narrowing, named after Robert H. Dicke, refers to narrowing of the Doppler broadening of a spectral line due to collisions the emitting species (usually an atom or a molecule) experiences with other particles. Mechanism When the mean free path of an atom is much smaller than the wavelength of the radiative transition, the atom changes velocity and direction many times ''during'' the emission or absorption of a photon. This causes an averaging over different Doppler states and results in an atomic linewidth that is narrower than the Doppler width. See also * Mössbauer effect * Motional narrowing * Stark effect and Zeeman effect The Zeeman effect () is the splitting of a spectral line into several components in the presence of a static magnetic field. It is caused by the interaction of the magnetic field with the magnetic moment of the atomic electron associated with ... References ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Motional Narrowing
In physics and chemistry, motional narrowing is a phenomenon where a certain resonant frequency has a smaller linewidth than might be expected, due to motion in an inhomogeneous system.''Solid state: nuclear methods'' by J. N. Mundy, section 6.2.1.1, page 441. The discovery of motional narrowing has been attributed to during his thesis work in the 1940s Example: NMR spectroscopy A common example is . In this process, the |
Perceptual Narrowing
Perceptual narrowing is a developmental process during which the brain uses environmental experiences to shape perceptual abilities. This process improves the perception of things that people experience often and causes them to experience a decline in the ability to perceive some things to which they are not often exposed.Scott, L. S., Pascalis, O., & Nelson, C. A. (2007). A domain-general theory of the development of perceptual discrimination. Current Directions in Psychological Science (Wiley-Blackwell), 16(4), 197-201. This phenomenon is a result of neuroplasticity, including Hebbian learningTichko, P., & Large, E. W. (2019). Modeling infants’ perceptual narrowing to musical rhythms: neural oscillation and Hebbian plasticity. Annals of the New York Academy of Sciences, 1453(1), 125–139. https://doi.org/10.1111/nyas.14050McClelland, J. L., Thomas, A. G., McCandliss, B. D., & Fiez, J. A. (1999). Understanding failures of learning: Hebbian learning, competition for representatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Q-based Narrowing
In the Neo-Gricean approach to semantics and pragmatics championed by Yale linguist Laurence Horn, the Q-principle ("Q" for "Quantity") is a reformulation of Paul Grice's maxim of quantity (''see'' Gricean maxims) combined with the first two sub-maxims of manner. The Q-principle states: "Say as much as you can (given R)." As such it interacts with the R-principle, which states: "Say no more than you must (given Q).""Implicature" in the ."The Gricean Model" in the Encyclopedi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stenosis
Stenosis () is the abnormal narrowing of a blood vessel or other tubular organ or structure such as foramina and canals. It is also sometimes called a stricture (as in urethral stricture). ''Stricture'' as a term is usually used when narrowing is caused by contraction of smooth muscle (e.g. achalasia, prinzmetal angina); ''stenosis'' is usually used when narrowing is caused by lesion that reduces the space of lumen (e.g. atherosclerosis). The term coarctation is another synonym, but is commonly used only in the context of aortic coarctation. Restenosis is the recurrence of stenosis after a procedure. Examples Examples of vascular stenotic lesions include: * Intermittent claudication (peripheral artery stenosis) * Angina ( coronary artery stenosis) * Carotid artery stenosis which predispose to (strokes and transient ischaemic episodes) * Renal artery stenosis Types In heart valves The types of stenoses in heart valves are: * Pulmonary valve stenosis, which is th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
