Search results
Results from the WOW.Com Content Network
A pyrgeometer is a device that measures near-surface infra-red (IR) radiation, approximately from 4.5 μm to 100 μm on the electromagnetic spectrum (thereby excluding solar radiation). It measures the resistance / voltage changes in a material that is sensitive to the net energy transfer by radiation that occurs between itself and its ...
The earliest example of a pyrometer thought to be in existence is the Hindley Pyrometer held by the London Science Museum, dating from 1752, produced for the Royal collection. The pyrometer was a well known enough instrument that it was described in some detail by the mathematician Euler in 1760.
The Feynman–Kac formula, named after Richard Feynman and Mark Kac, establishes a link between parabolic partial differential equations and stochastic processes.In 1947, when Kac and Feynman were both faculty members at Cornell University, Kac attended a presentation of Feynman's and remarked that the two of them were working on the same thing from different directions. [1]
Any non-linear differentiable function, (,), of two variables, and , can be expanded as + +. If we take the variance on both sides and use the formula [11] for the variance of a linear combination of variables (+) = + + (,), then we obtain | | + | | +, where is the standard deviation of the function , is the standard deviation of , is the standard deviation of and = is the ...
Test functions in real analysis and distribution theory, which are infinitely differentiable functions on the real line that are 0 everywhere outside of a given limited interval. An example of such a function is the test function, φ ( t ) = { e − 1 / ( 1 − t 2 ) , − 1 < t < 1 , 0 , otherwise . {\displaystyle \varphi (t)={\begin{cases}e ...
In order to increase the calculation speed for viscosity calculations based on CS theory, which is important in e.g. compositional reservoir simulations, while keeping the accuracy of the CS method, Pedersen et al. (1984, 1987, 1989) [17] [18] [2] proposed a CS method that uses a simple (or conventional) CS formula when calculating the reduced ...
This can be used to calculate mean values (expectations) of the flow rates, head losses or any other variables of interest in the pipe network. This analysis has been extended using a reduced-parameter entropic formulation, which ensures consistency of the analysis regardless of the graphical representation of the network. [3]
For example, a quadratic for the numerator and a cubic for the denominator is identified as a quadratic/cubic rational function. The rational function model is a generalization of the polynomial model: rational function models contain polynomial models as a subset (i.e., the case when the denominator is a constant).