An exercise machine including a weight measurement system which provides a signal representative of a user’s weight. This invention allows information relating to the source of an electronic document, whether the document is an original, document processing operations performed on the document, distribution of the document, and other historical characteristics be extracted from indicia applied to the document. The first flight path may include a substantially circular path that allows the aerial vehicle to generate the power. During a fluid flow surge event, the fluid flow diverting element is capable of diverting at least some of the fluid from the first fluid flow path to a second fluid flow path. A second set of wheels is disposed on the side of the tree stand and allows for tipped translation. Damage to the head is detected based on the determined actuation efficiency.