design effect of actions

[EnglishAbeille]

E(d,fi) is the design effect of actions for the fire situation <...> including effects of thermal expansions and deformations. (тематика: огнестойкость железобетонных конструкций)

Помогите со словосочетанием design effect of actions, пожалуйста.

[Coleen Bon]

Эх

The design effect (DEFF) is the ratio of the true variance of a statistic (taking the complex sample design into account) to the ----variance of the statistic for a simple random sample with the same number of cases. Design effects differ for different subgroups and different statistics; no single design effect is universally applicable to any given survey or analysis.

колебания свойств конструкции под воздействием тепла при пожаре

[EnglishAbeille]

Спасибо огромное.