Somewhat earlier, in medieval China, gunpowder had been invented, and was increasingly used by the military in combat. The use of gunpowder in the early vase-like mortars in Europe, and advanced versions of the long bow and cross bow, which all had armour-piercing arrowheads, that put an end to the dominance of the armoured knight. After the long bow, which required great skill and strength to use, the next most significant technological advance was the musket, which could be used effectively, with little training. In time, the successors to muskets and cannon, in the form of rifles and artillery, would become core battlefield technology.
The operational level is at a scale bigger than one where line of sight and the time of day are important, and smaller than the strategic level, where production and politics are considerations. Formations are of the operational level if they are able to conduct operations on their own, and are of sufficient size to be directly handled or have a significant impact at the strategic level. This concept was pioneered by the German army prior to and during the Second World War. At this level, planning and duration of activities takes from one week to a month, and are executed by Field Armies and Army Corps and their naval and air equivalents.[31]
In the Navy, the rank of Admiral of the Navy theoretically corresponds to that of General of the Armies, though it was never held by active-duty officers at the same time as persons who held the rank of Fleet Admiral. George Dewey is the only person to have ever held this rank. After the establishment of the rank of Fleet Admiral in 1944, the Department of the Navy specified that the rank of Fleet Admiral was to be junior to the rank of Admiral of the Navy. However, since Dewey died in 1917 before the establishment of the rank of Fleet Admiral, the six-star rank has not been totally confirmed.
Standard Scores are scores that have a fixed mean and standard deviation in the population of examinees. A Standard Score indicates how many units of the standard deviation a particular score is above or below the mean. In the case of the ASVAB subtests, the mean is set to 50 and the standard deviation is set to 10. Thus, a Standard Score of 40 indicates that the examinee scored 1 standard deviation below the mean. A Standard Score of 70 indicates that the examinee scored 2 standard deviations above the mean. To learn more about how standard scores are derived and used, click here.