âº EVC System. A disabled refuge is a relatively safe area within a building or exit staircase for mobility impaired occupants, allowing building management and emergency services to safely assist these people from the building.
Standard deviation is a number used to tell how measurements for a group are spread out from the average (mean), or expected value. A low standard deviation means that most of the numbers are very close to the average. A high standard deviation means that the numbers are spread out.
Nigel Clark, engineer. Views. The standard deviation is a calculated value of the square root of the variance which is an accumulation of each paired data set (data point less the mean) which is squared. The value is then divided by the number of data points. By adding a constant A, you adjust the mean by that constant and then subtract it out.