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.
Phase-shift keying. Phase-shift keying (PSK) is a digital modulation process which conveys data by changing (modulating) the phase of a reference signal (the carrier wave). The modulation occurs by varying the sine and cosine inputs at a precise time. It is widely used for wireless LANs, RFID and Bluetooth communication.