# effective

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**Effective demand**— In economics, effective demand in a market is the demand for a product or service which occurs when purchasers are constrained in a different market. It contrasts with notional demand, which is the demand that occurs when purchasers are not… …82

**Effective population size**— In population genetics, the concept of effective population size N e was introduced by the American geneticist Sewall Wright, who wrote two landmark papers on it (Wright 1931, 1938). He defined it as the number of breeding individuals in an… …83

**Effective interest rate**— The effective interest rate, effective annual interest rate, Annual Equivalent Rate (AER) or simply effective rate is the interest rate on a loan or financial product restated from the nominal interest rate as an interest rate with annual… …84

**Effective frequency**— In advertising, the effective frequency is the number of times a person must be exposed to an advertising message before a response is made and before exposure is considered wasteful.The subject on effective frequency is quite controversial. Many …85

**Effective dimension**— In mathematics, effective dimension is a modification of Hausdorff dimension and other fractal dimensions which places it in a computability theory setting. There are several variations (various notions of effective dimension) of which the most… …86

**Effective action**— In quantum field theory, the effective action is a modified expression for the action, which takes into account quantum mechanical corrections, in the following sense: In classical mechanics, the equations of motion can be derived from the action …87

**Effective temperature**— Star The effective temperature of a star is the temperature of a black body with the same luminosity per surface area (mathcal{F} {Bol}) as the star and is defined according to the Stefan–Boltzmann law mathcal{F} {Bol}=sigma T {eff}^4. Notice… …88

**Effective dose**— An effective dose in pharmacology is the amount of drug that produces a therapeutic response in 50% of the people taking it, sometimes also called ED 50. In radiation protection it is an estimate of the stochastic effect that a non uniform… …89

**Effective stress**— Karl von Terzaghi first proposed the relationship for effective stress in 1936. [http://fbe.uwe.ac.uk/public/geocal/SoilMech/stresses/stresses.htm] For him, the term ‘effective’ meant the calculated stress that was effective in moving soil, or… …90

**Effective method**— An effective method (also called an effective procedure) for a class of problems is a method for which each step in the method may be described as a mechanical operation and which, if followed rigorously, and as far as may be necessary, is bound… …