A convex function is a real-valued function defined on an interval with the property that its epigraph (the set of points on or above the graph of the function) is a convex set.
A rectifier is a electrical device that converts alternating current to direct current, a process known as rectification. Rectifiers are used as components of power supplies and as detectors of radio signals. Rectifiers may be made of solid state diodes, vacuum tube diodes, mercury arc valves, and other technologies.
Basic half wave rectifier circuit. The half wave rectifier circuit can be used in a number of different applications. The half wave rectifier circuit normally utilises a single diode. This passes one half of the cycle, and blocks the other. In this way only half of the cycle is used, but current is only allowed to flow in one direction.