Assertion: wave's value | /r/CapableOf | stay above the x-axis
Facets:
value: always
type: TEMPORAL
Source sentences:
text: The current of a direct current full-wave rectification system, used to convert AC into DC, can be modeled using an absolute value sine wave, where the wave is similar to a normal sine wave because the value always stays above the x-axis, but has twice as many peaks.