enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Error correction model - Wikipedia

    en.wikipedia.org/wiki/Error_correction_model

    The term error-correction relates to the fact that last-period's deviation from a long-run equilibrium, the error, influences its short-run dynamics. Thus ECMs directly estimate the speed at which a dependent variable returns to equilibrium after a change in other variables.

  3. Planck's law - Wikipedia

    en.wikipedia.org/wiki/Planck's_law

    1) The number r can be interpreted as the number of photons in the mode. For r = 0 the energy of the mode is not zero. This vacuum energy of the electromagnetic field is responsible for the Casimir effect . In the following we will calculate the internal energy of the box at absolute temperature T . According to statistical mechanics , the equilibrium probability distribution over the energy ...

  4. Vertex distance - Wikipedia

    en.wikipedia.org/wiki/Vertex_distance

    The formula for vertex correction is = (), where F c is the power corrected for vertex distance, F is the original lens power, and x is the change in vertex distance in meters. Derivation [ edit ] The vertex distance formula calculates what power lens ( F c ) is needed to focus light on the same location if the lens has been moved by a distance x .

  5. Penman–Monteith equation - Wikipedia

    en.wikipedia.org/wiki/Penman–Monteith_equation

    The Penman–Monteith equation approximates net evapotranspiration (ET) from meteorological data, as a replacement for direct measurement of evapotranspiration. The equation is widely used, and was derived by the United Nations Food and Agriculture Organization for modeling reference evapotranspiration ET 0 .

  6. Larmor formula - Wikipedia

    en.wikipedia.org/wiki/Larmor_formula

    This is a coherent process, so the total power radiated is proportional to the square of the number of electrons accelerating. In electrodynamics, the Larmor formula is used to calculate the total power radiated by a nonrelativistic point charge as it accelerates. It was first derived by J. J. Larmor in 1897, [1] in the context of the wave ...

  7. Snell's law - Wikipedia

    en.wikipedia.org/wiki/Snell's_law

    Snell's law (also known as the Snell–Descartes law, the ibn-Sahl law, [1] and the law of refraction) is a formula used to describe the relationship between the angles of incidence and refraction, when referring to light or other waves passing through a boundary between two different isotropic media, such as water, glass, or air.

  8. Prism compressor - Wikipedia

    en.wikipedia.org/wiki/Prism_compressor

    A prism compressor is an optical device used to shorten the duration of a positively chirped ultrashort laser pulse by giving different wavelength components a different time delay. It typically consists of two prisms and a mirror. Figure 1 shows the construction of such a compressor. Although the dispersion of the prism material causes ...

  9. Quadratic formula - Wikipedia

    en.wikipedia.org/wiki/Quadratic_formula

    Quadratic formula. The roots of the quadratic function y = 1 2 x2 − 3x + 5 2 are the places where the graph intersects the x -axis, the values x = 1 and x = 5. They can be found via the quadratic formula. In elementary algebra, the quadratic formula is a closed-form expression describing the solutions of a quadratic equation.