Reflectance values express the percentage of light that is reflected back from a surface, the difference having been absorbed or transmitted by the surface. Reflectances of room surfaces are used in determining coefficient of utilization values for luminaires.
The last three lines show you how to define your own awk function. The format is simple -- type function, then the function name, and then the parameters separated by commas, inside parentheses. After this, a { } code block contains the code that you'd like this function to execute.
When PPK stands for Process Performance Index, CPK stands for Process Capability Index. 2. CPK is a measure that tells how close an organisation is in achieving the target and how much consistent an organisation is with regard to average performance.