axial compression ratio and slenderness ratio

B-C ratio (benefit-cost ratio)

benefit-cost ratio (B-C ratio)

focal ratio (=focal-length ratio)

grinding ratio(G-ratio)

maximum ratio combing according to signal to noise ratio

recirculation ratio recycle ratio

recycle ratio recirculation ratio

signal-noise ratio (=signal-to-noise ratio =SNR)

stop ratio and start ratio in time segment

price--earnings ratio;P/E ratio

active daylight guidance system

artifical daylight

artificial daylight

as plain as daylight

Atlantic daylight time

burn daylight

by daylight

coefficient to adjust daylight average temperature