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.
Sample Standard Deviation. A standard deviation of a sample estimates the standard deviation of a population based on a random sample. The sample standard deviation, unlike the population standard deviation, is a statistic that measures the dispersion of the data around the sample mean.